# PHREEQC Evaporator

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Navigation: Models ➔ TCE Models ➔ PHREEQC Add-On ➔ PHREEQC Evaporator

Latest SysCAD Version: 2 August 2022 - SysCAD 9.3 Build 139.31388

Related Links: PHREEQC SysCAD Project Workflow, Potash Evaporator, Evaporator

## General Description

The Evaporator is used to 'flash' a feed stream to produce a liquid and vapour product at a set pressure or temperature. The unit may also have connections to an Embedded or External Heat Exchanger.

There are two operational modes for the Evaporator:

1. as a stand-alone unit; or
2. as part of a Flash Train.

The user sets the operational mode of the Evaporator. However, if the user sets the mode as Flash Train and the Evaporator is NOT connected to another Evaporator (Embedded Shell), Barometric Condenser, Heat Exchangers of any Flash Train aware destination unit, the model will go to an error state.

### Crystallization

The Evaporator model may be used as a Crystallizer, as it behaves in the same way. Vapour is flashed off and the remaining solution is then supersaturated with the required species. This species then precipitates out as the crystal product.

If the PHREEQC model being used by the PHREEQC Evaporator has solubility data for the species, then the amount of species that precipitates will be automatically calculated. The solution properties will be calculated by PHREEQC and by the selected SysCAD species model.

At this time, PHREEQC evaporation models are suitable for water evaporation. This is because gases are treated as pure phases in the PHREEQC calculations. Only insoluble gases can be included in these models.

### Heat Exchange Options

The user may select any of the following 3 options for heat exchange:

1. None - no Heat Exchange is required.
2. Embedded - The Embedded Heat Exchange model uses a Shell and Tube style heat exchanger. The user connects the Steam (or other cooling or heating medium) to the Embedded HX Shell connection and the Condensate (or return heat exchange medium) to the Embedded HX Shell. The recycle flow to the heat exchanger must to be specified, but this is handled internally within the unit.
3. External - External Heat Exchange models the use of external heat exchangers taking a recycle stream from the Evaporator contents and heating, or cooling, this recycle stream. The user must connect the Recycle stream from the Evaporator to an external heat exchanger. This recycle stream is either heated or cooled then returned to the Evaporator via the Recycle stream. The recycle flow to the heat exchanger must to be specified, and this is sent to the Recycle connection.

NOTES:

1. The difference between the two heat exchange methods:
• With Embedded heat exchange, the steam and condensate streams (or other heat exchange medium) are connected directly to Evaporator via the Embedded HX Shell connections. The Recycle stream to the heat exchanger is handled internally within the unit.
• With external heat exchange, the recycle stream is sent to an external heat exchanger via the Recycle output connection and returned to the Evaporator via the Recycle input connection.
2. For both Embedded and external heat exchange the user must set the recycle flow to the heat exchanger.

### Diagram

• The diagram shows default drawings of the Evaporator with connecting streams, with heat exchanger connections.
• The Heat Exchanger connections are optional.
• The user does not have to connect a stream to the 'Overflow' connection, as the Evaporator will operate without this connection.
• The physical location of the streams connecting to the Evaporator is unimportant. The user may connect the streams to any position on the unit.
• When inserting an Evaporator into a flowsheet, the user may choose a different symbol from the menu.

## Inputs and Outputs

 Label RequiredOptional InputOutput Number of Connections Description Min Max. Feed 1 Required In 1 20 Feed to the Evaporator. Embedded HX Shell Optional In 0 10 Inlet stream to the Shell side of internal Shell and Tube Heat Exchanger (often the steam inlet). Recycle Optional In 0 1 Recycle stream from an external Shell and Tube Heat Exchanger to the Evaporator. Product Required Out 1 1 Product Slurry outlet - this stream normally contains the majority of the solids. Vent Required Out 1 1 Vent outlet containing all Vapours from the unit. Overflow Optional Out 0 1 Overflow liquor outlet. Embedded HX Shell Optional Out 0 1 Outlet stream from the Shell side of internal Shell and Tube Heat Exchanger (often the condensate). Recycle Optional Out 0 1 Recycle stream from the Evaporator to an external Shell and Tube Heat Exchanger.

## Behaviour when Model is OFF

If the user disables the unit, by un-ticking the On tick box, then the following actions occur:

• All material in streams connected to the 'Feed' and 'Recycle' inlets will flow straight out of the 'Product' outlet, with no change in phase or energy exchange with material flowing through the internal heat exchanger;
• All material in streams connected to the 'Embedded HX Shell' connections will have no change in phase or energy exchange with material flowing through the Evaporator;
• No sub-models will be called.

So basically, the unit will be 'bypassed' without the user having to change any connections.

## Model Theory

Vapour Liquid Equilibrium

The unit is configured to achieve vapour : liquid equilibrium at a required pressure (or temperature) using the user defined VLE method. Any solids that may be in the stream entering the unit are ignored in the flash calculations. However the enthalpy balance does include the solids. For further information on the theory for the VLE calculations see Vapour Liquid Equilibrium (VLE).

Pressure used for Evaluation Block Calculations

For an Evaporator in the Stand Alone mode the calculations, including the PHREEQC Calculations may be performed at either:

• The Feed pressure; or
• The final pressure; or
• The pressure into the Body of the Evaporator if the user has chosen Final Temperature as the mode.

The user enables the 'UseFeedP' tickbox on the first tab of the Evaporator to use the Feed pressure.

Using the Feed or other pressure may produce small differences in the final results from the Evaporator.

### PHREEQC

The PHREEQC Evaporator Model uses the PHREEQC algorithms and data to determine the status of the aqueous solution.

Mapping of SysCAD to PHREEQC streams is done as illustrated below.

The streams are mixed using the SysCAD enthalpy context prior to being loaded into PHREEQC.

The PHREEQC Evaporator can be incorporated into a SysCAD flowsheet, it can be connected with SysCAD inlet and outlet streams.

1. User connects the PHREEQC Evaporator with SysCAD input streams,
2. The SysCAD feed stream(s) using SysCAD species is converted into PHREEQC "Input" using PHREEQC Species. The species mapping is defined in the corresponding PHREEQC Model Configuration unit model.
3. The PHREEQC Evaporator calls the PHREEQC algorithms to determine the status of the mixture using the converted PHREEQC "input" data.
4. The PHREEQC results are displayed in the "output" tab using PHREEQC species.
5. The results are converted back into SysCAD species. Please see Species Mapping for more information.

NOTES:

• The Input, Output and Diff tab pages are displayed using PHREEQC species, as defined in the PHREEQC database file (.dat) specified in the corresponding PHREEQC Model Configuration unit model.
• The species used in the SysCAD project are shown on the optional Sp pages, shown as part of the QFeed, QBypass, QUnmapped, QRxnProdBypass and QProd pages.
• The calculations performed are similar to using PHREEQC directly, except the contents of the SysCAD stream are mapped to equivalent PHREEQC species using the settings defined in the PHREEQC Model Configuration unit model. Please see wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc for more information.

### Calculation of Osmotic Pressure

PHREEQC calculates the activity of water, which is then used to calculate the osmotic pressure by the Van't Hoff formula. The Van't Hoff formula is:

$\displaystyle{ \Pi=-\frac{RT}{\overline{V}}ln(a_w) }$

where $\displaystyle{ \Pi }$ is the osmotic pressure, $\displaystyle{ \overline{V} }$ is the partial molar volume of water (ideal), and $\displaystyle{ a_w }$ is the activity of water (mole fraction basis).

## WorkFlow

The suggested workflow for configuring the model is:

1. Make sure the project contains at least one of the PHREEQC Model Configuration model, and the model is loaded with the correct PHREEQC database you would like to use for the PHREEQC Evaporator.
2. On the PHREEQCEvaporator Tab Page, select the correct "ChemModel" (to match step 1)
3. Configure the model - methods, pressures (if applicable)
4. Select any sub-models
5. Perform an equilibrium calculation by pressing Solve in SysCAD.
6. The Results are displayed in the PHREEQCResults and Output tabs.
7. Check and fix any species mapping issues. (PHREEQC resulting species may change if the operating conditions change, so it is likely a change of temperature or feed composition will result in different PHREEQC species.)

## Data Sections

The default access window consists of several sections:

1. Evaporator - The first tab contains general information relating to the unit and allows the user to set the Heat Exchange type and flows.
2. Results - This tab contains the results fields for the Evaporator.
3. HX - Optional tab, only visible if an Internal Heat Exchanger is selected. (In this case the Internal HX connections should be connected).
4. Separ - Only visible if the Overflow stream is connected. The tab allows the user to specify the split between the Product and Overflow streams.
5. VLE - Always on.
6. CFE - Optional tab, only visible if the UseCFE option is enabled on the first tab page.
7. Bypass - Always on, with H2O(g) bypassed.
8. PHREEQCResults tab - This tab displays the key results of the calculations.
9. Input tab - This tab displays a summary of the mapped Input stream as PHREEQC species.
10. Output tab - This tab displays the Output stream results including the amounts of each PHREEQC species present in the final mixture.
11. Diff tab - Optional tab, only visible if the ShowRxnDiff option is enabled on the first tab page. This tab displays the amounts of each species which are formed or reacted as part of the calculations.
12. ElemBal tab - This tab displays an elemental balance between the Input and Output streams.
13. PhDeport tab - Optional tab, only visible if the PhaseElemDeportment option is enabled on the first tab page. This tab shows the movement of elements for the Solid, Liquid and Gas phases.
14. IPhDeport tab - Optional tab, only visible if the IPhaseElemDeportment option is enabled on the first tab page. This tab shows the movement of elements for the individual PHREEQC phases.
15. ParamSweep tab - Optional tab, only visible if the ShowPlotter option is enabled on the first tab page. This tab allows the user to generate sets of data.
16. SpForPlot tab - Optional tab, only visible if the SelectSp option is enabled on the ParamSweep tab. This tab allows the user to select which species to be reported in the sets of data to be generated.
17. QUnmapped - Optional tab, only visible if ShowQUnmapped is enabled on the first tab page.
18. QBypass - Optional tab, only visible if ShowQBypass is enabled on the first tab page.
19. QRxnBypass - Optional tab, only visible if ShowQRxnBypass is enabled on the first tab page.
20. QFeed - Optional tab, only visible if ShowQFeed is enabled. This page shows the properties of the mixed stream as the feed to the Evaporator.
21. QBodyFeed - Optional tab, only visible if ShowQBodyFeed is enabled. This page shows the properties of the mixed stream as the feed to the Body of the Evaporator.
22. QRecycle - Optional tab, only visible if ShowQRecycle is enabled. This page shows the properties of the recycle stream.
23. QProd - This page shows the properties of the Evaporator discharge as a single stream.
24. Info tab - contains general settings for the unit and allows the user to include documentation about the unit and create Hyperlinks to external documents.
25. Links tab, contains a summary table for all the input and output streams.
26. Audit tab - contains summary information required for Mass and Energy balance. See Model Examples for enthalpy calculation Examples.

### Evaporator Page

Unit Type: Evaporator - The first tab page in the access window will have this name.

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options Tag Display This name tag may be modified with the change tag option. Condition Display OK if no errors/warnings, otherwise lists errors/warnings. ConditionCount Display The current number of errors/warnings. If condition is OK, returns 0. GeneralDescription / GenDesc Display This is an automatically generated description for the unit. If the user has entered text in the 'EqpDesc' field on the Info tab (see below), this will be displayed here. If this field is blank, then SysCAD will display the unit class ID. Requirements On Tickbox This variable in used to turn the unit ON or OFF. If this not ticked, the material will flow out of the Product outlet with no change in state, i.e. the unit acts as a pipe. Mode Stand Alone (Manual) The Evaporator will act as a 'Stand Alone' unit and the user may set the required operating Pressure or Temperature. Flash Train The Evaporator will act as part of a Flash Train. In this mode the Evaporator vent must be connected to a steam consumer, such as a Barometric Condenser, Shell and Tube Heat Exchanger, Shell and Tube Heat Exchanger 2 or a Direct Contact Heater. The steam requirements of the steam consumer will drive the operating pressure of the Evaporator, therefore the user may NOT set the operating temperature or pressure. OperatingP The user may only set the operating pressure or temperature of the Evaporator if it is NOT part of a Flash Train. Method Atmospheric This method is only available if 'Stand Alone' Mode is chosen. All flash calculations will be done at Atmospheric Pressure. The atmospheric pressure is calculated by SysCAD based on the user defined elevation (default elevation is at sea level = 101.325 kPa). The elevation can be changed on the Environment tab page of the Plant Model. RequiredP This method is only available if 'Stand Alone' Mode is chosen. All flash calculations will be done at the user specified pressure (and saturated temperature @ P). RequiredT This method is only available if 'Stand Alone' Mode is chosen. All flash calculations will be done at the user specified temperature (and saturated pressure @ T). Saturated 'The OperatingP - Method will be set to Saturated if 'Flash Train' Mode is chosen. All flash calculations will be done at the saturated pressure. PressureReqd / P_Reqd Input This field is only visible if the RequiredP method is chosen. This is user specified flash pressure. TemperatureReqd / T_Reqd Input This field is only visible if the RequiredT method is chosen. This is user specified flash temperature. Result Calc The actual pressure used for the sum of the feeds which will also be the outlet pressure (unless further model options change the pressure). MinFlashP Input This is only visible when 'Flash Train' Mode is chosen. The Minimum Flash Pressure. UseFeedP Tickbox This is only visible if the mode = Stand Alone. If this field is enabled then all of the Evaluation Block calculations will be performed at the Feed pressure. Otherwise, if it is not enabled, the calculations will be performed at the final pressure. See also Model Theory. ======== Body PHREEQC Block ======== This program contains PHREEQC Copyright U.S. Geological Survey (USGS) Requirements Select actions if species unmapped FwdSpMap.UnmappedAction Bypass Any unmapped SysCAD species will be bypassed, ie will not be present in the PHREEQC input Stop Solver Any unmapped SysCAD species will cause the solver to stop, user will need to fix the species mapping before solving again. RevSpMap.UnmappedAction Make Inactive The unit model will become "inactive" (off) if a required PHREEQC product species is unmapped. Stop Solver Any unmapped PHREEQC product species will cause the solver to stop, user will need to fix the species mapping before solving again. Allow Solve Any unmapped PHREEQC product species will be ignored, the results may have mass balance issues. User will need to check the species and fix mapping if the species is important. Chemistry Model ChemModel... UnitTag List The tag of the relevant PHREEQC Model Configuration unit model- this may be chosen from the drop down list of all PHREEQC Model Configuration unit models available in the project. ChemModel.Selected Display The tag of the relevant PHREEQC Model Configuration unit model. Check If the user clicks on this button, SysCAD will check that the UnitTag is a valid PHREEQC Model Configuration unit model. ConnOK Tickbox If SysCAD finds a valid PHREEQC Model Configuration unit model, then this field will be enabled. Status OK The specified chemistry model (PHREEQC Model Configuration) has been initialised correctly and the database file has been found and loaded correctly. ChemModel Tag not Specified No tag has been specified for the Chemistry Model. Specify the desired Chemistry Model (PHREEQC Model Configuration) in the UnitTag field. Valid ChemModel Tag Required The tag specified for the Chemistry Model in the UnitTag field is invalid and needs to be corrected. Init Required The specified Chemistry Model (PHREEQC Model Configuration) needs to be initialised. ChemModel Load Required The database of the specified Chemistry Model (PHREEQC Model Configuration) needs to be loaded. DLL or Version Error There is a problem with the PHREEQC DLL or version. Init Failed Initialisation of the specified Chemistry Model (PHREEQC Model Configuration) has been attempted but failed. UseCFE Tickbox If this is ticked, then the CFE (Constrained Free Energy) tab page will appear. If CFE is not available, this ticked box will be greyed out. This option allows a portion of a species to be locked up and not allowed to react. Applying CFE can have a significant effect on the final composition, use of this feature requires detailed knowledge of the process chemistry. WithBypass Tickbox Always On, the Bypass tab page will be set with steam bypass = 100%. Options ShowQUnmapped Tickbox Allows the user to view the QUnmapped and associated tab pages. See Material Flow Section. This is the SysCAD species flows which are not mapped to PHREEQC species, and therefore are not taken into account in the PHREEQC calculation. ShowQBypass Tickbox Only visible when WithBypass is ticked. Allows the user to view the QBypass and associated tab pages. See Material Flow Section. This is the SysCAD species flows which bypass the PHREEQC calculation. ShowQRxnBypass Tickbox Only visible when WithBypass is ticked. Allows the user to view the QRxnBypass and associated tab pages. See Material Flow Section. ShowRxnDiff Tickbox Allows the user to view the Diff tab page. This shows the difference between the mapped input stream seen by PHREEQC and the PHREEQC calculation results. ShowPlotter Tickbox Only visible after the model has been successfully solved for at least one iteration. Allows the user to perform a parameter sweep using the product stream of the unit. If this is ticked, then the ParamSweep tab page will appear. ShowSpIonRebuildRxns Tickbox If this is ticked, then the SpIonRxns tab page will appear. This shows how ions from the PHREEQC product stream were assembled into SysCAD species. PhaseElemDeportment Tickbox Allows the user to view the Phase element deportment tab page. This shows how the elements move between phases due to the PHREEQC calculation results. IPhaseElemDeportment Tickbox Allows the user to view the IPhase element deportment tab page. This shows how the elements move between individual phases due to the PHREEQC calculation results. CopyPHREEQCInputToClipboard When this button is pressed, user can select to copy the Feed or Product information to clipboard. PHREEQC Environmental Heat Transfer PHREEQC.HeatLossMethod None No heat transfer between the unit and the environment. Fixed HeatFlow The user specifies a fixed heat loss between the unit and the environment. Ambient SysCAD calculates the overall heat loss based on user specified HTC and Area and the temperature difference between the Feed and environmental temperatures. The environmental temperature is assumed to remain constant. PHREEQC.EHX.HeatLossReqd Input Visible when the HeatLossMethod = Fixed HeatFlow. The required heat loss. PHREEQC.EHX.HTC Input Visible when the HeatLossMethod = Ambient. The Overall Heat Transfer coefficient. PHREEQC.EHX.Area Input Visible when the HeatLossMethod = Ambient. The Heat Transfer area. PHREEQC.EHX.AmbientT Display Visible when the HeatLossMethod = Ambient. The ambient temperature. The ambient temperature is specified in the Plant Model - Environment_Tab PHREEQC.EHX.HeatLoss Calc Visible when the HeatLossMethod = Ambient. The calculated heat flowrate. Vapour Entrainment FlashVapToLiquid Input This field allows the user to set a proportion of the flash vapour bypassing to the liquid stream. The default is 0%. OtherGasToLiquid Input This field allows the user to set a proportion of any non-condensable gas bypassing to the liquid stream. The default is 0%. Evaporator Heat Exchanger Options HXType None The unit is not connected to a Heat Exchanger. No other fields are visible for the Heat Exchanger if this option is chosen. External The Evaporator is connected to an External Heat Exchanger unit. This external unit may be any type of SysCAD model. Embedded Heater The Evaporator contains an Embedded Heater. If this option is chosen, an additional page HX becomes visible and the user configures the Heat Exchanger within the Evaporator. Embedded Cooler The Evaporator contains an Embedded Cooler. If this option is chosen, an additional page HX becomes visible and the user configures the Heat Exchanger within the Evaporator. HXOut.SplitMethod Off No flow is sent to the Heat Exchanger. Ratio to Feed MassFlow The flow to the Heat Exchanger (either Embedded or External) is a Ratio of the Feed mass. The composition and temperature of the stream to the Heat Exchanger is the same as the Combined Feed to the Evaluation Block. Ratio to Prod MassFlow The flow to the Heat Exchanger (either Embedded or External) is a Ratio of the Product mass. The composition and temperature of the stream to the Heat Exchanger is the same as the Product from the Evaluation Block. Note: The Product mass includes both the Overflow and the Product streams. MassFlow The flow to the Heat Exchanger (either Embedded or External) is a fixed mass flow. The composition and temperature of the stream to the Heat Exchanger is the same as the Product from the Evaluation Block. Note: The Product mass includes both the Overflow and the Product streams. VolumeFlow The flow to the Heat Exchanger (either Embedded or External) is a fixed volumetric flow. The composition and temperature of the stream to the Heat Exchanger is the same as the Product from the Evaluation Block. Note: The Product mass includes both the Overflow and the Product streams. MassFlow Per Heater This option can be used for the Embedded Heater option, where user can define the number heaters used. The flow to each Embedded Heater is mass based. The composition and temperature of the stream to the Heat Exchanger is the same as the Product from the Evaluation Block. Note: The Product mass includes both the Overflow and the Product streams. VolumeFlow Per Heater This option can be used for the Embedded Heater option, where user can define the number heaters used. The flow to each Embedded Heater is volume based. The composition and temperature of the stream to the Heat Exchanger is the same as the Product from the Evaluation Block. Note: The Product mass includes both the Overflow and the Product streams. HXOut.RatioToFeedQm Input The flow to the Heat Exchanger (either Embedded or External) is Feed Flow times by Ratio. HXOut.RatioToProdQm Input The flow to the Heat Exchanger (either Embedded or External) is Product Flow times by Ratio. Note: The Product mass includes both the Overflow and the Product streams. HXOut.MassFlowRqd Input The required Product mass flow to the Heat Exchanger (either Embedded or External). HXOut.VolumeFlowRqd Input The required Product volumetric flow to the Heat Exchanger (either Embedded or External). HXOut.EachHeaterQmRqd Input The required Product mass flow to the each Heater (Embedded Heater method only). HXOut.EachHeaterQvRqd Input The required Product volumetric flow to the each Heater (Embedded Heater method only). Options VapStandardSpModel Tickbox This forces the vent stream to revert to the Standard species model. If this is NOT ticked, then the species model in the vent will be the same as the species model used in the Evaporator.Normally this is left ticked, as the vent contains steam and the Standard species model will calculate all of the properties of steam correctly. ShowQFeed Tick Box QFeed and associated tab pages (e.g. Qm) will become visible if this is enabled. These tabs will show the properties of the combined feed stream to the Unit. These values are BEFORE the Evaluation Block is processed. ShowQBodyFeed Tick Box QBodyFeed and associated tab pages (e.g. Qm) will become visible if this is enabled. These tabs will show the properties of the feed to the Evaporator Body. ShowQRecycle Tickbox This is only visible if an Embedded Heat Exchanger is used. If this option is ticked then the recycle stream to the Heat Exchanger is displayed as 'QRecycle' and the user may access properties of the stream feeding the Heat Exchanger. ShowQProd Tick Box QProd and associated tab pages (eg Qm) will become visible if this is enabled. These tabs will show the properties of the product stream from the Unit, AFTER the Evaluation Block is processed, but BEFORE the stream is split to overflow and product.

### Results Page

The page contains the results and the user may enable the Heat Exchanger function and set the type of Heat Exchanger (Internal or External) and the flow to the Heat Exchanger.

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options Operating Conditions TemperatureIn / Ti Calc The temperature of the combined Feed stream to the Evaporator. PressureIn / Pi Calc The pressure of the combined Feed stream to the Evaporator. VapFlashed.MassFlow / VapFlashed.Qm Calc The quantity of flashed vapour. BPE Calc The Boiling Point Elevation used in the Flash calculations in the Evaporator. FlashT Calc The final temperature (the Flash Temperature) in the Evaporator. FlashP Calc The final pressure (the Flash Pressure) in the Evaporator. Flash Train Macro Model These extra fields are only visible if the unit is part of a Flash Train. VapourMassFlow / VQm Calc The mass flow of flashed vapour. PressureReqd / P_Reqd Calc The required flash pressure calculated by the Flash Train. TotalPressChange / TotaldP Calc The total pressure change calculated by the Flash Train. FlashTrain Display A unique tag assigned to the flash train by SysCAD. Each unit in the flash train will have the same tag in this block. FlashTearBlock Display Displays the name of the tear block that is part of the Flash Train. FlashTrainEqp List This contains a list of all of the equipment tags in this flash train. the list might be as follows: FT_EVAPORATOR_2_HX FT_EVAPORATOR_1_Evap PAdvBase Input Additional damping or acceleration for calculated pressure change (DP) for the iteration. DP = DP * PAdvBase when PAdvExtra=0. PAdvExtra Input Additional damping or acceleration for calculated pressure change (DP) for the iteration. DP = DP * (PAdvBase + PAdvExtra*(VQmReqd-VQm)/Max(VQmReqd,VQm)). Summary of input and output streams The following tags are shown for Feed, Vapour, Overflow (OF) and Product (Prod) streams: Temperature / T Display The temperature of the stream. MassFlow / Qm Display The Mass flowrate of the stream. SolidMassFlow / SQm Display The solids Mass Flow of the stream. SolidFrac / Sf Display The solids Mass fraction of the stream. Results BFeed.Temperature / BFeed.T Calc The temperature of the Feed to the Evaporator evaluation block. BFeed.Pressure / BFeed.P Calc The Pressure used in the calculations in the Evaporator evaluation block. If the user has ticked the 'UseFeedP' then this will be the feed pressure to the Evaporator. BFeed.MassFlow / BFeed.Qm Calc The mass flow of Feed to the Evaporator evaluation block. BFeed.SolidMassFlow /BFeed.SQm Calc The mass flow of solids to the Evaporator evaluation block. Body.SolidsYield Calc The mass flow of solids in the Product - mass flow of solids in the Feed. SolidsYield Calc The mass flow of solids in the Product - mass flow of solids in the Feed. Evaporator to Embedded or External Heater / Cooler HXOut.MassFlow / HXOut.Qm Calc The mass flow to the specified Heat Exchanger. HXOut.EachHeaterQm Calc The mass flow to the specified Heat Exchanger (per heater if more than one is used). HXOut.VolFlow / HXOut.Qv Calc The volume flow to the specified Heat Exchanger. HXOut.EachHeaterQv Calc The volume flow to the specified Heat Exchanger (per heater if more than one is used). HXOut.Temperature / HXOut.T Calc The temperature of the stream to the specified Heat Exchanger. Embedded Heater Recycle Loop convergence RecycleConvergeMethod FullStream User can select to solve the recycle loop using Full stream data (loop has to solve and converge all mass and energy terms.) Stream Mass Only User can select to solve the recycle loop using mass only. Loop will be solved when mass is converged, ignoring energy. Duty User can select to solve the recycle loop using energy only. Duty from "shell" side of heat exchanger is added directly to the feed (recycle mass flow is not actually added). Loop will be solved when duty is matched, ignoring mass balance. MaxIter(Global) Input The maximum number of iteration allowed within the recycle solver loop. Only shown for Stream Recycle Converge Methods. IterSteps Calc The number of iteration used in the current step to solve the recycle loop. Only shown for Stream Recycle Converge Methods. IterLastStep Calc The number of iteration used in the last step to solve the recycle loop. Only shown for Stream Recycle Converge Methods. IterMaxInAStep Calc The maximum number of iterations (in a step) used to solve the recycle loop. Only shown for Stream Recycle Converge Methods. IterTotal Calc The total number of iterations used to solve the recycle loop. Only shown for Stream Recycle Converge Methods. FeedMaxDuty Calc The maximum amount of Duty that can be added to feed before temperature exceeds water critical temperature. Only shown for Duty Recycle Converge Method. IterDuty Calc The number of iterations to apply duty and flash. When this is greater then 1 then the Duty from the condensing steam is applied in iterations, the values displayed on the VLE page reflect this. Only shown for Duty Recycle Converge Method.

### HX Page

HX - Optional tab, only visible if an Internal Heat Exchanger is selected. (In this case the Internal HX connections should be connected).

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options Heater / Cooler Requirements On Tick Box Switches the Embedded Heat Exchanger on/off NumofHeater Input Visible when Embedded Heater / cooler is used. Specifies the number of embedded heat exchangers in the evaporator. Type Fixed Heat Flow This will exchange a fixed amount of heat between two streams. No phase change will take place automatically. Sensible This will allow sensible heat exchange between two streams. No phase change will take place. Condensing Only visible when Embedded Heater is used. This is used to condense the steam. Steam must be connected to Embedded HX Shell (inlet). Evaporating Only visible when Embedded Cooler is used. This is used to evaporate the water. Water (or another component with Predefined Flashing Data) must be connected to Embedded HX Shell (inlet). CondensingMethod (Only visible when Embedded Heater is used) All The Steam addition is manually specified by the user. All steam will condense. All (Calc Demand) The steam demand is calculated base on the user specified Heater HTC and Area (UA). User needs to set the steam flow based on the calculated amount. All-Demand General The steam supply comes from (directly or indirectly) a Feeder with Demand.on selected. All-Demand Flashtrain The steam supply comes from another process unit in Flash train mode (usually the vapour from the preceding evaporation stage) EvaporatingMethod (Only visible when Embedded Cooler is used) All The component defined in the VLE Tab will fully evaporate. All (Calc Demand) The demand is calculated base on the user specified Heater HTC and Area (UA). User needs to set the flow based on the calculated amount. All-Demand General The flow supply comes from (directly or indirectly) a Feeder with Demand.on selected. DutyReqd Input The required fixed heat flow to be exchanged between the two streams. Only visible when Fixed Heat Flow method is used. HTC Input/Calc Visible with method set to any of the demand methods, allows the user to specify the heat transfer coefficient. Area Input/Calc Visible with method set to any of the demand methods, allows the user to specify the heat transfer area per heater. Heater / Cooler Results Duty Calc The calculated Heat Exchanger Duty TotalArea Calc The total Area used (HX Area * number of HX). U*A / UA Calc The heat exchanger UA. LMTD Calc The calculated log mean temperature difference. TheoreticalDuty / TheorDuty Calc The theoretical duty of the heat exchanger. HeatFlow Calc The total heat exchanged. Calculated Vapour/Liquid Flow Demand DemandFlow.Reqd Calc The calculated demand flow to meet the Heat Exchanger requirements. When the HX is not in Demand General or Demand FlashTrain mode, use a General controller or SetTag Controller to get this value to set the Embedded HX Shell (in) flowrate. DemandFlow.Actual Calc The actual demand flow to Heater Exchanger . DemandFlow.Error Calc The mass imbalance in the unit operation. This will warn the user if the amount of flow supplied exceeds the heat exchanger requirements. Most common when the heater is not in Demand General or Demand FlashTrain mode and the steam flow has not been set up to auto adjust. Tube Side (Recycle Stream) Tube.TemperatureIn / Tube.Ti Calc Tube in temperature. Tube.TemperatureOut / Tube.To Calc Tube out temperature. Tube.PressureIn / Tube.Pi Calc Tube in pressure. Tube.MassFlow / Tube.Qm Calc The mass flowrate going through the tube side.. Shell Side (Condensing / Evaporating) Shell.TemperatureIn / Shell.Ti Calc Shell in temperature. Shell.TemperatureOut / Shell.To Calc Shell out temperature. Shell.PressureIn / Shell.Pi Calc Shell in pressure. Shell.MassFlow / Shell.Qm Calc The mass flowrate going through the Shell side. Shell.DmdQm Calc Only visible if part of a flash train. This is the amount of steam needed from connected flash train units (flash tank or steam feeders), not including any fixed amount of steam input. Shell.FxdQm Calc Only visible if part of a flash train. This is the amount of steam added in manually, thus not from connected flash train units. Note this portion of steam addition is not included in the pressure calculation of the flash train group. Flash Train Macro Model Note: Extra fields are visible if the unit is part of a Flash Train. These fields are described below. Please refer to Flash Train. VapourMassFlowReqd / VQmReqd Calc The calculated mass flow of steam required by the Embedded Heater Condenser. CondMassFlow / CondQm Calc The amount of steam condensed by the Embedded Heater Condenser. MinSatPress Calc The minimum saturated pressure of steam that could satisfy the heating requirements of the Embedded Heater Condenser. FlashTrain Display A unique tag assigned to the flash train by SysCAD. Each unit in the flash train will have the same tag in this block. FlashTearBlock Display Displays the name of the tear block that is part of the Flash Train. FlashTrainEqp List This contains a list of all of the equipment tags in this flash train. the list might be as follows: FT_EVAPORATOR_2_HX FT_EVAPORATOR_3_Evap PAdvBase Input Additional damping or acceleration for calculated pressure change (DP) for the iteration. DP = DP * PAdvBase when PAdvExtra=0. PAdvExtra Input Additional damping or acceleration for calculated pressure change (DP) for the iteration. DP = DP * (PAdvBase + PAdvExtra*(VQmReqd-VQm)/Max(VQmReqd,VQm)).

### Separ Page

The page allows the user to specify the split between the Underflow and Overflow streams.

Tag (Long/Short) Input / Calc Description/Calculated Variables / Options
Requirements
Split Method Mass Fraction The users may specify the mass fraction split between the Underflow and Overflow streams.
Mass Flow The user may specify the mass flow to either the Underflow or Overflow stream - either as total flow or on a phase basis.
Volume Fraction The users may specify the volumetric fraction split between the Underflow and Overflow streams.
Volume Flow The user may specify the Volume flow to either the Underflow or Overflow stream - either as total flow or on a phase basis.
Solid Separation The user may specify the solid split between the Underflow and Overflow streams.
Each of the above Split Methods will be described separately below:

#### Mass Fraction

With this method the user can specify the mass fraction to either the Underflow or the Overflow on a total or by phase basis.

SplitTo Underflow The user specifies the mass fraction split to the Underflow stream.
Overflow The user specifies the mass fraction split to the Overflow stream.
SplitBy Total The user specifies the total mass fraction split to the defined stream.
Phase The user specifies the solid and liquid mass fraction splits to the defined stream.
FracToUF or FracToOF Input This is visible if SplitBy = Total. The user sets the total mass fraction split to the defined stream.
SolidsToUF or SolidsToOF Input This is visible if SplitBy = Phase. The user sets the solid mass fraction split to the defined stream.
LiquidsToUF or LiquidsToOF Input This is visible if SplitBy = Phase. The user sets the liquid mass fraction split to the defined stream.

#### Mass Flow

With this method the user can specify the mass flow to either the Underflow or the Overflow on a total or by phase basis.

SplitTo Underflow The user specifies the mass flow to the Underflow stream.
Overflow The user specifies the mass flow to the Overflow stream.
SplitBy Total The user specifies the total mass flow to the defined stream.
Phase The user specifies the solid mass flow and the liquid mass flow to the defined stream.
UF or OF.MassFlowReqd /
UF or OF.QmReqd
Input This is visible if SplitBy = Total. The user sets the total mass flow to the defined stream.
UF or OF.SolidMassFlowReqd /
UF or OF.SolidQmReqd
Input This is visible if SplitBy = Phase. The user sets the solid mass flow to the defined stream.
UF or OF.LiquidMassFlowReqd /
UF or OF.LiquidQmReqd
Input This is visible if SplitBy = Phase. The user sets the liquid mass flow to the defined stream.

#### Volume Fraction

With this method the user can specify the volume fraction to either the Underflow or the Overflow on a total or by phase basis.

SplitTo Underflow The user specifies the volume fraction split to the Underflow stream.
Overflow The user specifies the volume fraction split to the Overflow stream.
SplitBy Total The user specifies the total volume fraction split to the defined stream.
Phase The user specifies the solid and liquid volume fraction splits to the defined stream.
FracToUF or FracToOF Input This is visible if SplitBy = Total. The user sets the total volume fraction split to the defined stream.
SolidsToUF or SolidsToOF Input This is visible if SplitBy = Phase. The user sets the solid volume fraction split to the defined stream.
LiquidsToUF or LiquidsToOF Input This is visible if SplitBy = Phase. The user sets the liquid volume fraction split to the defined stream.

#### Volume Flow

With this method the user can specify the volume flow to either the Underflow or the Overflow on a total or by phase basis.

SplitTo Underflow The user specifies the volume flow to the Underflow stream.
Overflow The user specifies the volume flow to the Overflow stream.
SplitBy Total The user specifies the total volume flow to the defined stream.
Phase The user specifies the solid Volume flow and the liquid volume flow to the defined stream.
UF or OF.VolFlowReqd /
UF or OF .QvReqd
Input This is visible if SplitBy = Total. The user sets the total volume flow to the defined stream.
UF or OF.SolVolFlowReqd /
UF or OF.SolidQvReqd
Input This is visible if SplitBy = Phase. The user sets the solid volume flow to the defined stream.
UF or OF.LiqVolFlowReqd /
UF or OF.LiquidQvReqd
Input This is visible if SplitBy = Phase. The user sets the liquid volume flow to the defined stream.

#### Solid Separation

With this method the user can choose between setting the solids composition of the Overflow stream or defining the Underflow flowrate and then specifying the solids composition of the Underflow.

SolidsSeparMethod OF Solids Fraction The user specifies the solids mass fraction in the Overflow stream.
OF Solids Conc The user specifies the solids concentration in the Overflow stream.
OF Solids Conc25 The user specifies the solids concentration at 25°C in the Overflow stream.
Recovery to UF The user specifies the solids recovery to the Underflow stream, i.e. how much of the solids in the unit reports to the Underflow stream.
UF MassFlow The user specifies the total mass flow of the Underflow stream.
UF VolumeFlow The user specifies the total volume flow of the Underflow stream.
Solids Density Each solid species is split between the Overflow and Underflow streams based on the user specified SolidsCutDensity.
Solids PSD The user then specifies one of the Solid Methods for defining a partition curve which then separates the solids based on PSD data in the feed.
OFSolidFracReqd Input This is visible if SolidsSeparMethod = OF Solids Fraction. The user sets the solids mass fraction in the Overflow stream.
OFSolidConcReqd Input This is visible if SolidsSeparMethod = OF Solids Conc. The user sets the solids concentration in the Overflow stream.
OFSolidConc25Reqd Input This is visible if SolidsSeparMethod = OF Solids Conc25. The user sets the solids concentration at 25°C in the Overflow stream.
SolidsToUFReqd Input This is visible if SolidsSeparMethod = Recovery to UF. The user sets the mass fraction of solids in the unit that must report to the Underflow stream.
UFQmReqd Input This is visible if SolidsSeparMethod = UF MassFlow. The user sets the total mass flow of the Underflow stream.
UFQvReqd Input This is visible if SolidsSeparMethod = UF VolumeFlow. The user sets the total volume flow of the Underflow stream.
CutDensityMethod This is visible if SolidsSeparMethod = Solids Density.
Simple If the density of a solid species is greater than the SolidsCutDensity then it is all sent to the Underflow stream, otherwise it is all sent to the Overflow stream.
Erf An error function is used to determine the split of each solid species between the Overflow and Underflow streams based on the species density, SolidsCutDensity and alpha.
Logistic This method is based on a Logisitic type of function. It is used to determine the split of each solid species between the Overflow and Underflow streams based on the species density, SolidsCutDensity and alpha.
SolidsCutDensity Input This is visible if SolidsSeparMethod = Solids Density. The user sets the solids cut density which is used to determine how much of each solid species to send to the Overflow and Underflow streams.
ErfAlpha Input This is visible if SolidsSeparMethod = Solids Density and CutDensityMethod = Erf. User specified efficiency parameter, alpha. See Erf Cut Density Method for more information.
LogisticAlpha Input This is visible if SolidsSeparMethod = Solids Density and CutDensityMethod = Logistic. User specified efficiency parameter, alpha. See Logistic Cut Density Method for more information.
SolidsBypassToUF Input This is visible if SolidsSeparMethod = Solids Density. The fraction of solids which bypasses the separation by density calculations and passes straight to the underflow.
The following Solids Method (with Solids PSD) assumes the Solid-Liquid separator is used to emulate the screen.
Solid Separation Requirements.
SolidMethod Simple (no PSD) The feed does not need size distribution for this method and the unit acts as a simple mass splitter. If the user chooses this mode then they must define the solids and liquids split from the unit. (This option is visible for the Screen 2 model only)
Partition Curve The user inputs a Partition curve (fraction of feed solids per size interval reporting to the oversize) on the PartCrv(deck number) tab. The screen will use this curve, so the size distribution in the feed to the screen has no effect on products.
Note: A single partition curve is used for all the size distributions.
Whiten The screen model will calculate the solids split using the Whiten method. The user must specify the d50 and alpha, a measure of the sharpness of separation.
Karra The screen model will calculate the solids split using the Karra method. The user may specify either the d50 or the Screen area and Cut aperture.
Rosin-Rammler This method is based on a Rosin-Rammler type of function with the efficiency curve expression derived by Reid and Plitt. User must specify d50, sharpness of separation, maximum size allowed to undersize and minimum percent of solids reporting to oversize.
Lynch This method is based on a Lynch type of function. User must specify d50, sharpness of separation (m), maximum size allowed to undersize and minimum percent of solids reporting to oversize.
DelVillar-Finch This method is similar to Rosin-Rammler, but includes a term for the "fish hook" effect for entrainment.

#### Solid Method - Whiten

Whiten.CalcMethod d50 The user specifies the d50 of the screen.
d50 with Beta The user specifies the d50 of the screen and uses the Beta method to adjust for uncertainties in the finer fractions.
Aperture, Eff The user specifies the Screen Aperture and Efficiency. The unit then calculates the d50 of the Screen deck.
Aperture, Eff with Beta The user specifies the Screen Aperture and Efficiency and uses the Beta method to adjust for uncertainties in the finer fractions. The unit then calculates the d50 of the Screen deck.
Whiten.Aperture Input Only visible if one of the two Aperture CalcMethods are chosen. The Screen Aperture, used to calculate the d50.
Whiten.Efficiency / Eff Input The Whiten Efficiency of the Screen.
• If the user selects one of the 'Aperture' methods, then this is used to calculate the d50.
• If the user selects one of the 'd50' methods, then this value is used to calculate the Screen aperture (see Theoretical Nominal Screen Aperture).
Whiten.d50 Input/Calc If either of the d50 methods are chosen, this is entered by the user. If the Aperture method is chosen, this is a calculated value. This is the particle size with a 50% probability of reporting to the over or under size.
Whiten.Alpha Input The Efficiency parameter, alpha. An alpha value of between 8 and 15 is normal for screening. However, this does depend on the screening conditions and hence experience and/or test or plant data is required for accurate results.
Whiten.Beta Input Only visible if the d50 with Beta or Aperture,Eff with Beta CalcMethods are chosen. The Beta Efficiency parameter. This value takes into account uncertainties in the finer size fractions.
Whiten.Beta* Calc Only visible if the d50 with Beta or Aperture,Eff with Beta CalcMethods are chosen. Efficiency parameter.
Whiten.MaxSizeToUS Input The model will ensure that all particles LARGER than this size all report to the Screen deck oversize product. This value is often = Screen Deck Aperture. (See Model Theory).
Whiten.MinToOS Input The model will ensure that a minimum fraction of solids in each size distribution reports to the oversize product. For example, if the user specifies a minimum of 5%, then at least 5% of each size distribution will report to oversize. (See Model Theory).
Whiten.Rf Input The proportion of feed liquid reporting to the over size product to be used in the fines calculation.
Note: This value is only used to adjust the solids fine fraction to the screen oversize and NOT to set the fraction of liquid reporting to the oversize stream.

If the user has selected SolidMethod=Whiten and Whiten.CalcMethod = d50 or d50 with Beta, the following fields will be visible:

Theoretical Nominal Screen Aperture

Whiten.Efficiency / Eff Input The Whiten Efficiency of the Screen. Used to calculate the Screen aperture.
Whiten.TheorAperture Calc The calculated screen aperture, based on the specified d50, alpha and efficiency. Refer to equation 2 in Whiten Method.

#### Solid Method - Karra

Karra.CalcMethod d50 The user specifies the d50 of the screen.
Area The user specifies the Area and Cut aperture of the screen and the model calculates the d50 of the screen.
Karra.d50 Input Only visible if CalcMethod=d50. The user specified d50 of the screen.
Karra.TotalArea Input Only visible if CalcMethod=Area. The deck area.
Karra.Aperture Input Only visible if CalcMethod=Area. The deck cut aperture.
Karra.Wet Tick Box Only visible if CalcMethod=Area. This must be ticked if this is a wet screening application.
Karra.Factor Input Only visible if CalcMethod=Area. This is a tuning factor that may be used to adjust the calculated d50 of the screen deck. The default value is 1.
Karra.MaxSizeToUS Input The model will ensure that all particles LARGER than this size all report to the Screen deck oversize product. This value is often = Screen Deck Aperture. (See Model Theory).
Karra.MinToOS Input The model will ensure that a minimum fraction of solids in each size distribution reports to the oversize product. For example, if the user specifies a minimum of 5%, then at least 5% of each size distribution will report to oversize. This accounts for fines adhering to coarse particles or fines in the liquid.
Karra.Calc_d50 Calc Only visible if CalcMethod=Area. The calculated d50 of the deck, using the Karra equations.
Karra.d50 Calc Only visible if CalcMethod=Area. The d50 that is used to determine the screen partition curve. This is normally equal to the field above. But, if the calculated d50 > screen deck aperture, then the model will use the screen deck aperture.
Karra.FeedOversize Calc Only visible if CalcMethod=Area. The fraction of oversize material (Q) in the Feed to the deck.
Karra.FeedHalfsize Calc Only visible if CalcMethod=Area. The fraction of half size material (R) in the Feed to the deck.
Karra.FeedNearsize Calc Only visible if CalcMethod=Area. The fraction of near size material (Xn) in the Feed to the deck.
Karra.SolQmPerArea Calc Only visible if CalcMethod=Area. The calculated solids flow rate divided by the screen area.

#### Solid Method - Rosin-Rammler

RR.d50 Input The user specifies the d50 of the screen, the size which divides equally between oversize and undersize.
RR.Sharpness Input The user specifies the sharpness factor for separation, high values for sharper separation
RR.MaxSizeToUS Input The maximum size allowed to report to undersize.
RR.MinToOS Input The minimum percent solids (from feed) to report to oversize.

#### Solid Method - Lynch

Lynch.d50 Input The user specifies the d50 of the screen, the size which divides equally between oversize and undersize.
Lynch.Sharpness (m) Input The user specifies the sharpness factor for separation, high values for sharper separation.
Lynch.Alpha Calc Calculated from the Sharpness (m), refer to Lynch Method for more information.
Lynch.MaxSizeToUS Input The maximum size allowed to report to undersize.
Lynch.MinToOS Input The minimum percent solids (from feed) to report to oversize.

#### Solid Method - DelVillar-Finch

Finch.d50 Input The user specifies the d50 of the screen, the size which divides equally between oversize and undersize.
Finch.Sharpness Input The user specifies the sharpness factor (m) for separation, high values of m for sharper separation
Finch.d0 Input The largest particle size affected by the fish-hook for entrainment function.
Finch.MaxSizeToUS Input The maximum size allowed to report to undersize.
Finch.MinToOS Input The minimum percent solids (from feed) to report to oversize.
Finch.Rf Input Proportion of feed liquid reporting to the over size product.
UnderFlow (or Oversize Material when using PSD) Requirements
UFSolidsMethod UF Solids Fraction The user specifies the solids mass fraction in the Underflow stream.
UF Solids Conc The user specifies the Solids concentration in the Underflow stream.
UF Solids Conc25 The user specifies the Solids concentration in the Underflow stream at 25°C.
UF Density The user specifies the density of the Underflow stream.
UFSolidFracReqd Input This is visible if UFSolidsMethod = UF Solids Fraction. The user sets the solids mass fraction in the Underflow stream.
UFSolidConcReqd Input This is visible if UFSolidsMethod = UF Solids Conc. The user sets the solids concentration in the Underflow stream.
UFSolidConc25Reqd Input This is visible if UFSolidsMethod = UF Solids Conc25. The user sets the solids concentration at 25°C in the Underflow stream.
UFRhoReqd Input This is visible if UFSolidsMethod = UF Density. The user sets the density of the Underflow stream.

#### Selected Solid Species Calculation Method

With this method the user may specify fractions of any number of solid species to bypass to either the Underflow or Overflow streams, or the user may specify the bypass to both Over and Under flow streams. Please see the examples in Model Theory.

Method None There is no overriding of solid species to the Underflow or Overflow streams.
Bypass to Underflow The user may specify the fractions of one or more Solid species that bypass to the Underflow stream.
Bypass to Overflow The user may specify the fractions of one or more Solid species that bypass to the Overflow stream.
Bypass to Both The user may specify the fractions of one or more Solid species that bypass the Solid-Liquid calculation block and is then split between the Over and Under flow streams.
BypassSeparCalcs Tick Box If this is enabled then the unit will NOT include the bypassed species fraction in the solid/liquid separation calculations. If it is not ticked, then the unit will include the fraction of bypassed species in the solid/liquid separation calculations. Please see the examples in Model Theory for clarification.
ShowByPassSolids Tick Box If this is enabled then the Count and Speciesx fields will be shown, otherwise they will be hidden.
Count Input Only visible if ShowByPassSolids is enabled. The number of solid species for which the user wishes to configure bypasses. This may be up to 10 species.
Solids Species Overall Bypass to Underflow, Overflow or Both
Speciesx Species List Only visible if ShowByPassSolids is enabled. The user may select a species from a drop down list of all of the Solid species in the project.
BypassFracx Input The user sets that fraction of species x that must bypass to the Underflow or Overflow streams OR that must bypass Both.
Example 1: The user chooses Bypass to Overflow, with Count = 1, Species1 = B(s) and BypassFrac1 = 10%, then 10% of B(s) will bypass the solids separation step and will report to the Overflow stream. 90% of B(s) will be involved in the solid-liquid calculation.
Example 2: The user chooses Bypass to Both, with Count = 1, Species1 = B(s), BypassFrac1 = 100% and FracToOF1 = 10%. ALL of B(s) will bypass the solids separation step, 10% of B(s) and will report to the Overflow stream and the remaining 90% will report to the Underflow stream.
FracToOFx Input This field is only visible if the user selects Bypass to Both. The user sets that fraction of species x that must bypass to the Overflow streams.
For example: The user chooses Bypass to Both, with Count = 1, Species1 = C(s), FracToOf1 = 100% and FracToOF1 = 50%. ALL of the C(s) will bypass the solids separation step, 50% of C(s) and will report to the Overflow stream and 50% will report to the Underflow stream.

#### Results

Temperature / T Display The temperature of mixture in the solid liquid separator.
MassFlow / Qm Display The total mass flow to the Underflow and Overflow streams.
VapourMassFlow / VQm Display The total flow of vapour to the Underflow and Overflow streams. (This does NOT include the vapour to the Vent)
UF.BypassMassFlow / UF.BypassQm Display The mass flow of the material that bypasses the underflow.
OF.BypassMassFlow / OF.BypassQm Display The mass flow of the material that bypasses the overflow.
BypassMassFlow / BypassQm Display The mass flow of the solids in the unit that bypasses the separation section.
UF.SolidsTakeoffQm Display Only visible for Classifying Precipitator. The solids mass flow takeoff from the underflow for recycle.
UF.SolidsTakeoffFrac Display Only visible for Classifying Precipitator. The mass fraction of solids in the underflow that reports to takeoff for recycle.
UF.FinalSf Display Only visible for Classifying Precipitator. The final underflow solids mass fraction after removal of solids takeoff.

#### Slurry Separation Results

If the BypassSeparCalcs tickbox is selected (visible with Solid Species Bypass Calculation Method used), then the table heading will display "Slurry Separation Results (excluding bypass)"

UFSolidsRecovery Display The fraction of feed solids sent to the underflow.
UFLiquidRecovery Display The fraction of feed liquid sent to the underflow.
The following table displays the flows and compositions of the Underflow and Overflow streams. Note: These are for slurry only, vapours are excluded.
MassFlow / Qm Display The total mass flow in each of the Underflow and Overflow streams.
VolFlow / Qv Display The total volume flow in each of the Underflow and Overflow streams.
SolidMassFlow / SQm Display The solids mass flow in each of the Underflow and Overflow streams.
LiquidMassFlow / LQm Display The liquid mass flow in each of the Underflow and Overflow streams.
SolidFrac / Sf Display The solid fraction in each of the Underflow and Overflow streams.
Density / Rho Display The total density of each of the Underflow and Overflow streams.
SolidConc Display The solid concentration (mass of solids/density of slurry) in each of the Underflow and Overflow streams.
SolidConc25 Display The solid concentration at 25°C (mass of solids/density of slurry at 25°C) in each of the Underflow and Overflow streams.

### CFE tab page

This tab is only visible if the UseCFE option is enabled on the first tab page.

• This option allows a portion of a species to be locked up and not allowed to react.
• Applying CFE can have a significant effect on the final composition, use of this feature requires detailed knowledge of the process chemistry.
• This feature is unavalable if using SysCAD VLE with PHREEQC.
 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options Constrained Free Energy (CFE) Configuration CFE... SpeciesName The Species:Long or Short button is used to change the display of the Species names between the Short form, the Chemical compound, or the longer species names. Filter View Filter This button will enable or disable the species filter options. ShowUnmapped(Only visible if Filter is enabled) Tickbox When enabled, all species will be displayed. When disabled, only species that are mapped to a SysCAD species will be shown. Phases(Only visible if Filter is enabled) All No filtering of species based on phase. Solids Only show solid phase species, hide other species. Liquids Only show liquid phase species, hide other species. Vapours Only show vapour (gaseous) phase species, hide other species. Solids & Liquids Only show solid and liquid phase species, hide other species. Solids & Vapours Only show solid and vapour (gaseous) phase species, hide other species. Liquids & Vapours Only show liquid and vapour (gaseous) phase species, hide other species. IPhase Only show "IPhase" individual phase species, hide other species. The individual phases shown will depend on the PHREEQC database chosen. Filters Display Always set to 'Content'. Content(Only visible if Filter is enabled) All No filtering of species based on element or name. Contains Any Element This will display all species that contain any of the elements entered in their elemental definition. Contains All Elements This will display only species that contain ALL of the elements entered in their elemental definition. Starts with ... This will display species that start with the text entered based on the short or long species tag depending on the current SpeciesTag selection. Contains any ... This will display species that contain the text entered in the currently displayed short or long species tag. Contains All ... This will display species that contain ALL the separate text entered in the currently displayed short or long species tag. Select Input Only visible if Filter is enabled and Content is NOT set to All. The user specified Elements or text to filter the species list. Refer to Species Filter for more information and examples. (The following tables (one per phase) display the PHREEQC species from the selected database. The user can set the Inert Fraction for each species. Note that liquid ions are not shown on this page as the Inert Fractions cannot be set for them.)(Each table has the following column (one row per PHREEQC species):) InertFrac Input The user specified fraction of the species that is considered inert, ie. cannot react to form other species/ions. The presence of the inert fraction is still taken into account when calculating stream properties. This is only available as an input for molecular species (not ions).

### Bypass tab page

This tab is only visible if the WithBypass option is enabled on the first tab page. This will allow some or all of the SysCAD species to bypass the thermodynamic engine calculations.

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options Species bypass configuration BypassMode Species A bypass fraction can be set for each species in the project. Phases A bypass fraction can be set for each phase (Solid, Liquid or Vapour) in the project. BypassUnmapped If this button is pressed then the bypass fraction for all Unmapped Species will be set to 100%. This is only relevant if BypassMode = Species. NOTE: There is no automatic undo for this function. It is recommended to bypass all species in the SysCAD model which are not present in the PHREEQC model you are using. ShowUnmappedSpecies Tickbox If ticked, all the unmapped species will be displayed in a list immediately under this field. PhaseBypass... (only displayed if BypassMode = Phases) PhaseBypass.Solid.MF Input Only displayed if BypassMode = Phases. The user specified Bypass fraction for all SysCAD solid species. A non-zero value will allow some or all (100%) of the SysCAD solid species to bypass the thermodynamic engine calculations. PhaseBypass.Liquid.MF Input Only displayed if BypassMode = Phases. The user specified Bypass fraction for all SysCAD liquid species. A non-zero value will allow some or all (100%) of the SysCAD liquid species to bypass the thermodynamic engine calculations. PhaseBypass.Vapour.MF Input Only displayed if BypassMode = Phases. The user specified Bypass fraction for all SysCAD vapour species. A non-zero value will allow some or all (100%) of the SysCAD vapour species to bypass the thermodynamic engine calculations. The remaining fields are only displayed if BypassMode = Species) On This button will enable or disable the species filter options. Phases(Only visible if Filter is enabled) All No filtering of species based on phase. Solids Only show solid phase species, hide other species. Liquids Only show liquid phase species, hide other species. Vapours Only show vapour (gaseous) phase species, hide other species. Solids & Liquids Only show solid and liquid phase species, hide other species. Solids & Vapours Only show solid and vapour (gaseous) phase species, hide other species. Liquids & Vapours Only show liquid and vapour (gaseous) phase species, hide other species. IPhase Only show "IPhase" individual phase species, hide other species. The individual phases shown will depend on the PHREEQC database chosen. Filters Display Always set to 'Content'. Content(Only visible if Filter is enabled) All No filtering of species based on element or name. Contains Any Element This will display all species that contain any of the elements entered in their elemental definition. Contains All Elements This will display only species that contain ALL of the elements entered in their elemental definition. Starts with ... This will display species that start with the text entered based on the short or long species tag depending on the current SpeciesTag selection. Contains any ... This will display species that contain the text entered in the currently displayed short or long species tag. Contains All ... This will display species that contain ALL the separate text entered in the currently displayed short or long species tag. Select Input Only visible if Filter is enabled and Content is NOT set to All. The user specified Elements or text to filter the species list. Refer to Species Filter for more information and examples. GroupValue Input The user specified bypass value that will be used for all species displayed when the Set to GroupValue button is pressed. SetVisible When pressed, this button will set the bypass parameter for all species currently displayed (based on Filter settings) equal to the GroupValue. SysCAD Feed Stream Bypass (The following table displays all the SysCAD species in the project (unless restricted by the Filter settings). The table has the following column (one row per SysCAD species):) Bypass.XXX Input The user specified Bypass fraction for SysCAD species XXX. A non-zero value will allow some or all (100%) of the SysCAD species to bypass the thermodynamic engine calculations.

### PHREEQCResults tab page

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options PHREEQC Calculation Results Summary Feed Massflow Summary Bypass.MassFlow / Qm Display The mass flow of material in the feed which bypasses the calculation due to user selection of bypass species. Use show ShowQBypass to view full stream. Unmapped.MassFlow / Qm Display The mass flow of material in the feed which is not forward mapped to a species and therefore bypasses the calculation. Use show ShowQUnmapped to view full stream. PHREEQC.Feed.MassFlow / Qm Display The mass flow of material in the feed to the PHREEQC calculation. Same value as tag Feed.Qm. TotalFeed.MassFlow / Qm Display The total feed mass to the PHREEQC model block. Sum of bypasses and feed to PHREEQC calculation. Product Massflow Summary PHREEQC.Prod.MassFlow / Qm Display The mass flow of material in the product of the PHREEQC calculation. Same value as tag Prod.Qm. RxnBypass.MassFlow / Qm Display The mass flow of material for RxnUnmapped.MassFlow / Qm Display The mass flow of material in the prod which is not reverse mapped to SysCAD species. TotalProd.MassFlow / Qm Display The total product mass for the PHREEQC model block. Sum of bypasses and product of PHREEQC calculation. Stream Properties Summary Prod... Temperature / T Display The Temperature of the final solution. Pressure / P Display The Pressure of the final solution. MassFlow / Qm Display The Mass flow of the final solution. [email protected] Display The Enthalpy of the final solution per unit mass. Enthalpy / [email protected] Display The Enthalpy of the final solution. AqDensity / AqRho Display The density of aqueous species (solution) in the final solution. IonicStrength / I Display The molar Ionic Strength of the final solution. pH Display The pH of the final solution. Alkalinity Display The alkalinity of the final solution. WaterActivity Display The water activity of the final solution. TotalDissolvedSolids / TDS Display The mass concentration of Total Dissolved Solids (total aqueous-water) in the final solution. OsmoticPressure / OsmP Display The Osmotic Pressure of the final solution. ElecConductivity / [email protected] Display The electric conductivity of the final solution. pKw Display The pKw of the final solution. Feed... Feed Phase Flowrate Summary PhaseZeros If the Hide Zeros button is clicked, all species that have NO mass flow will be hidden.If the Show Zeros button is clicked, all species will be displayed, including those with zero mass flow. (The following table displays a summary of results for the different phases. The table has the following columns (one row per phase)): MassFlow / Qm Display The mass flow of the relevant phase in the feed. MassFrac / Mf Display The mass fraction of the relevant phase in the feed. MoleFlow / QMl Display The mole flow of the relevant phase in the feed. MoleFrac / Mlf Display The mole fraction of the relevant phase in the feed. Prod... Prod Phase Flowrate Summary PhaseZeros If the Hide Zeros button is clicked, all species that have NO mass flow will be hidden.If the Show Zeros button is clicked, all species will be displayed, including those with zero mass flow. (The following table displays a summary of results for the different phases. The table has the following columns (one row per phase)): MassFlow / Qm Display The mass flow of the relevant phase in the final solution. MassFrac / Mf Display The mass fraction of the relevant phase in the final solution. MoleFlow / QMl Display The mole flow of the relevant phase in the final solution. MoleFrac / Mlf Display The mole fraction of the relevant phase in the final solution. Energy Balance PHREEQC.HeatFlow Display Difference in enthalpy between the product and feed of the PHREEQC reactions calculated by SysCAD. Bypass.HeatFlow Display The heat required to adjust the temperature and pressure of the bypass stream to exit conditions. HeatLoss Display The environmental heat loss. HeatFlow Display The heat flow required to achieve the product conditions relative to the feed conditions. Includes environmental heat loss if applicable. This is calculated by SysCAD and accounts for bypass and heat loss. Note that Bypass heat is calculated by SysCAD. Summary... Calculation Summary LastCalcType Display This displays the type of calculation (OpMode) used for the last calculation. LastCalcTime Display The amount of time taken to calculate the last set of conditions. Remove If the user clicks on this button, SysCAD will remove duplicate error messages received. ErrorCount Display The total number of errors encountered in the last calculation. ErrorXX Display If there are error messages associated with the last calculation, they will be displayed here. ConvergenceError Display The largest numerical convergence error. This is often zero when the solution converges with no errors.

### Input tab page

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options Stream Properties Summary Feed... Temperature / T Display The Temperature of the feed solution. This is calculated using the SysCAD enthalpy context. Pressure / P Display The Pressure of the feed solution. Enthalpy / [email protected] Display The Enthalpy of the feed solution. This is calculated using the SysCAD enthalpy context. Feed... SpeciesName The Species:Long or Short button is used to change the display of the Species names between the Short form, the Chemical compound, or the longer species names. Zeros If the Hide Zeros button is clicked, all species that have NO mass flow will be hidden.If the Show Zeros button is clicked, all species will be displayed, including those with zero mass flow. StreamView If the Mass button is clicked, the species will be shown in mass flow view. If the Mole button is clicked, the species will be shown in mole flow view. Stream Mass Copy stream contents to clipboard, mass basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Mole Copy stream contents to clipboard, mole basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Unmapped Mass Copy unmapped stream contents to clipboard, mass basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Unmapped species are those which will not be mapped to the exiting SysCAD stream. Unmapped Mole Copy unmapped stream contents to clipboard, mole basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Unmapped species are those which will not be mapped to the exiting SysCAD stream. Filter View Filter This button will enable or disable the species filter options. ShowUnmapped(Only visible if Filter is enabled) Tickbox When enabled, all species will be displayed. When disabled, only species that are mapped to a SysCAD species will be shown. Phases(Only visible if Filter is enabled) All No filtering of species based on phase. Solids Only show solid phase species, hide other species. Liquids Only show liquid phase species, hide other species. Vapours Only show vapour (gaseous) phase species, hide other species. Solids & Liquids Only show solid and liquid phase species, hide other species. Solids & Vapours Only show solid and vapour (gaseous) phase species, hide other species. Liquids & Vapours Only show liquid and vapour (gaseous) phase species, hide other species. IPhase Only show "IPhase" individual phase species, hide other species. The individual phases shown will depend on the PHREEQC database chosen. Filters(Only visible if Filter is enabled) Content All species which meet the Phase and Content criteria will be displayed. Content & MassFrac Limit Only species which meet the Phase and Content criteria AND have a mass fraction greater than or equal to the user specified MassFrac.Limit will be displayed. Content & MassFrac Largest Only the top N species (based on Mass Fraction) which meet the Phase and Content criteria will be displayed, where N = the user specified MassFrac.Count. Content & MassFrac Smallest Only the bottom N species (based on Mass Fraction) which meet the Phase and Content criteria will be displayed, where N = the user specified MassFrac.Count. MassFrac Limit Only species which meet the Phase criteria AND have a mass fraction greater than or equal to the user specified MassFrac.Limit will be displayed. MassFrac Largest Only the top N species (based on Mass Fraction) which meet the Phase criteria will be displayed, where N = the user specified MassFrac.Count. MassFrac Smallest Only the bottom N species (based on Mass Fraction) which meet the Phase criteria will be displayed, where N = the user specified MassFrac.Count. Content(Only visible when one of the Content Filter options is selected) All No filtering of species based on element or name. Contains Any Element This will display all species that contain any of the elements entered in their elemental definition. Contains All Elements This will display only species that contain ALL of the elements entered in their elemental definition. Starts with ... This will display species that start with the text entered based on the short or long species tag depending on the current SpeciesTag selection. Contains any ... This will display species that contain the text entered in the currently displayed short or long species tag. Contains All ... This will display species that contain ALL the separate text entered in the currently displayed short or long species tag. Select Input Only visible if Content is NOT set to All. The user specified Elements or text to filter the species list. Refer to Species Filter for more information and examples. MassFrac.Limit Input Only visible if Filters = Content & MassFrac Limit or MassFrac Limit. The user specified MassFrac Limit, the maximum mass fraction to be displayed. MassFrac.Count Input Only visible if Filters = Content & MassFrac Largest, Content & MassFrac Smallest, MassFrac Largest or MassFrac Smallest. The user specified Mass Frac Count, the maximum number of species to be displayed. (The following tables display the mass/mole flow, mass/mole fraction of the individual species.)(Each table (one for each phase) has the following columns (one row for each species):) MassFlow / Qm Display Visible when StreamView = Mass. The mass flow of the species in the feed stream. MassFrac / Mf Display Visible when StreamView = Mass. The mass fraction of the species in the feed stream. PhaseMassFrac / IPh:Mf Display Visible when StreamView = Mass. The mass fraction of the species in the displayed phase. MoleFlow / QMl Display Visible when StreamView = Mole. The mole flow of the species in the feed stream. MoleFrac / Mlf Display Visible when StreamView = Mole. The mole fraction of the species in the feed stream. PhaseMoleFrac / IPh:Mlf Display Visible when StreamView = Mole. The mole fraction of the species in the displayed phase.

### Output tab page

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options Stream Properties Summary Prod... Temperature / T Display The Temperature of the product solution. This is calculated using the SysCAD enthalpy context. Pressure / P Display The Pressure of the product solution. Enthalpy / [email protected] Display The Enthalpy of the product solution. This is calculated using the SysCAD enthalpy context. AqDensity / AqRho Display The density of aqueous species (solution) in the final solution. IonicStrength / I Display The molal Ionic Strength of the final solution, based on the molality (moles/mass of H2O) and charge of the individual ions. pH Display The pH of the final solution. Alkalinity Display The alkalinity of the final solution. WaterActivity Display The water activity of the final solution. TotalDissolvedSolids / TDS Display The mass concentration of Total Dissolved Solids (total aqueous-water) in the final solution. OsmoticPressure / OsmP Display The Osmotic Pressure of the final solution. Please refer to Model Theory - Calculation of Osmotic Pressure for more information. ElecConductivity / [email protected] Display The electric conductivity of the final solution. pKw Display The pKw of the final solution. RevMap.IonRxns A table of Ion Rebuild Reactions (ions->species) and their extents will be copied to the clipboard. Prod... SpeciesName The Species:Long or Short button is used to change the display of the Species names between the Short form, the Chemical compound, or the longer species names. Zeros If the Hide Zeros button is clicked, all species that have NO mass flow will be hidden.If the Show Zeros button is clicked, all species will be displayed, including those with zero mass flow. StreamView If the Mass button is clicked, the species will be shown in mass flow view. If the Mole button is clicked, the species will be shown in mole flow view. Stream Mass Copy stream contents to clipboard, mass basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Mole Copy stream contents to clipboard, mole basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Unmapped Mass Copy unmapped stream contents to clipboard, mass basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Unmapped species are those which will not be mapped to the exiting SysCAD stream. Unmapped Mole Copy unmapped stream contents to clipboard, mole basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Unmapped species are those which will not be mapped to the exiting SysCAD stream. Filter View Filter This button will enable or disable the species filter options. ShowUnmapped(Only visible if Filter is enabled) Tickbox When enabled, all species will be displayed. When disabled, only species that are mapped to a SysCAD species will be shown. Phases(Only visible if Filter is enabled) All No filtering of species based on phase. Solids Only show solid phase species, hide other species. Liquids Only show liquid phase species, hide other species. Vapours Only show vapour (gaseous) phase species, hide other species. Solids & Liquids Only show solid and liquid phase species, hide other species. Solids & Vapours Only show solid and vapour (gaseous) phase species, hide other species. Liquids & Vapours Only show liquid and vapour (gaseous) phase species, hide other species. IPhase Only show "IPhase" individual phase species, hide other species. The individual phases shown will depend on the PHREEQC database chosen. Filters(Only visible if Filter is enabled) Content All species which meet the Phase and Content criteria will be displayed. Content & MassFrac Limit Only species which meet the Phase and Content criteria AND have a mass fraction greater than or equal to the user specified MassFrac.Limit will be displayed. Content & MassFrac Largest Only the top N species (based on Mass Fraction) which meet the Phase and Content criteria will be displayed, where N = the user specified MassFrac.Count. Content & MassFrac Smallest Only the bottom N species (based on Mass Fraction) which meet the Phase and Content criteria will be displayed, where N = the user specified MassFrac.Count. MassFrac Limit Only species which meet the Phase criteria AND have a mass fraction greater than or equal to the user specified MassFrac.Limit will be displayed. MassFrac Largest Only the top N species (based on Mass Fraction) which meet the Phase criteria will be displayed, where N = the user specified MassFrac.Count. MassFrac Smallest Only the bottom N species (based on Mass Fraction) which meet the Phase criteria will be displayed, where N = the user specified MassFrac.Count. Content(Only visible when one of the Content Filter options is selected) All No filtering of species based on element or name. Contains Any Element This will display all species that contain any of the elements entered in their elemental definition. Contains All Elements This will display only species that contain ALL of the elements entered in their elemental definition. Starts with ... This will display species that start with the text entered based on the short or long species tag depending on the current SpeciesTag selection. Contains any ... This will display species that contain the text entered in the currently displayed short or long species tag. Contains All ... This will display species that contain ALL the separate text entered in the currently displayed short or long species tag. Select Input Only visible if Content is NOT set to All. The user specified Elements or text to filter the species list. Refer to Species Filter for more information and examples. MassFrac.Limit Input Only visible if Filters = Content & MassFrac Limit or MassFrac Limit. The user specified MassFrac Limit, the maximum mass fraction to be displayed. MassFrac.Count Input Only visible if Filters = Content & MassFrac Largest, Content & MassFrac Smallest, MassFrac Largest or MassFrac Smallest. The user specified Mass Frac Count, the maximum number of species to be displayed. (The following tables display the mass/mole flow, mass/mole fraction of the individual species.)(Each table (one for each phase) has the following columns (one row for each species):) MassFlow / Qm Display Visible when StreamView = Mass. The mass flow of the species in the product stream. MassFrac / Mf Display Visible when StreamView = Mass. The mass fraction of the species in the product stream. PhaseMassFrac / IPh:Mf Display Visible when StreamView = Mass. The mass fraction of the species in the displayed phase. MoleFlow / QMl Display Visible when StreamView = Mole. The mole flow of the species in the product stream. MoleFrac / Mlf Display Visible when StreamView = Mole. The mole fraction of the species in the product stream. PhaseMoleFrac / IPh:Mlf Display Visible when StreamView = Mole. The mole fraction of the species in the displayed phase. ActivityCoeff Display Only shown for liquid/aqueous or solid species. The activity coefficient of the species. Fugacity Display Only shown for gaseous species. The fugacity of the species.

### Diff tab page

This tab is only visible if ShowRxnDiff is ticked. The displayed results are the difference between input and output streams.

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options Stream Properties Summary Diff... Temperature / T Display The Temperature difference between the feed and product solutions. This is calculated using the SysCAD enthalpy context. Pressure / P Display The Pressure difference between the feed and product solutions. Enthalpy / [email protected] Display The Enthalpy difference between the feed and product solutions. This is calculated using the SysCAD enthalpy context. Diff... SpeciesName The Species:Long or Short button is used to change the display of the Species names between the Short form, the Chemical compound, or the longer species names. Zeros If the Hide Zeros button is clicked, all species that have NO mass flow will be hidden.If the Show Zeros button is clicked, all species will be displayed, including those with zero mass flow. StreamView If the Mass button is clicked, the species will be shown in mass flow view. If the Mole button is clicked, the species will be shown in mole flow view. Stream Mass Copy stream contents to clipboard, mass basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Mole Copy stream contents to clipboard, mole basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Unmapped Mass Copy unmapped stream contents to clipboard, mass basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Unmapped species are those which will not be mapped to the exiting SysCAD stream. Unmapped Mole Copy unmapped stream contents to clipboard, mole basis, for pasting into Excel. If Zeros is set to hide, zero values will not be copied to the clipboard. Unmapped species are those which will not be mapped to the exiting SysCAD stream. Filter View Filter This button will enable or disable the species filter options. ShowUnmapped(Only visible if Filter is enabled) Tickbox When enabled, all species will be displayed. When disabled, only species that are mapped to a SysCAD species will be shown. Phases(Only visible if Filter is enabled) All No filtering of species based on phase. Solids Only show solid phase species, hide other species. Liquids Only show liquid phase species, hide other species. Vapours Only show vapour (gaseous) phase species, hide other species. Solids & Liquids Only show solid and liquid phase species, hide other species. Solids & Vapours Only show solid and vapour (gaseous) phase species, hide other species. Liquids & Vapours Only show liquid and vapour (gaseous) phase species, hide other species. IPhase Only show "IPhase" individual phase species, hide other species. The individual phases shown will depend on the PHREEQC database chosen. Filters(Only visible if Filter is enabled) Content All species which meet the Phase and Content criteria will be displayed. Content & MassFrac Limit Only species which meet the Phase and Content criteria AND have a mass fraction greater than or equal to the user specified MassFrac.Limit will be displayed. Content & MassFrac Largest Only the top N species (based on Mass Fraction) which meet the Phase and Content criteria will be displayed, where N = the user specified MassFrac.Count. Content & MassFrac Smallest Only the bottom N species (based on Mass Fraction) which meet the Phase and Content criteria will be displayed, where N = the user specified MassFrac.Count. MassFrac Limit Only species which meet the Phase criteria AND have a mass fraction greater than or equal to the user specified MassFrac.Limit will be displayed. MassFrac Largest Only the top N species (based on Mass Fraction) which meet the Phase criteria will be displayed, where N = the user specified MassFrac.Count. MassFrac Smallest Only the bottom N species (based on Mass Fraction) which meet the Phase criteria will be displayed, where N = the user specified MassFrac.Count. Content(Only visible when one of the Content Filter options is selected) All No filtering of species based on element or name. Contains Any Element This will display all species that contain any of the elements entered in their elemental definition. Contains All Elements This will display only species that contain ALL of the elements entered in their elemental definition. Starts with ... This will display species that start with the text entered based on the short or long species tag depending on the current SpeciesTag selection. Contains any ... This will display species that contain the text entered in the currently displayed short or long species tag. Contains All ... This will display species that contain ALL the separate text entered in the currently displayed short or long species tag. Select Input Only visible if Content is NOT set to All. The user specified Elements or text to filter the species list. Refer to Species Filter for more information and examples. MassFrac.Limit Input Only visible if Filters = Content & MassFrac Limit or MassFrac Limit. The user specified MassFrac Limit, the maximum mass fraction to be displayed. MassFrac.Count Input Only visible if Filters = Content & MassFrac Largest, Content & MassFrac Smallest, MassFrac Largest or MassFrac Smallest. The user specified Mass Frac Count, the maximum number of species to be displayed. (The following tables display the mass/mole flow, mass/mole fraction of the individual species.)(Each table (one for each phase) has the following columns (one row for each species):) MassFlow / Qm Display Visible when StreamView = Mass. The difference in mass flow of the species. MassFrac / Mf Display Visible when StreamView = Mass. The difference in mass fraction of the species. PhaseMassFrac / IPh:Mf Display Visible when StreamView = Mass. The difference in mass fraction of the species in the displayed phase. MoleFlow / QMl Display Visible when StreamView = Mole. The difference in mole flow of the species. MoleFrac / Mlf Display Visible when StreamView = Mole. The difference in mole fraction of the species. PhaseMoleFrac / IPh:Mlf Display Visible when StreamView = Mole. The difference in mole fraction of the species in the displayed phase.

### ElemBal tab page

This tab performs an element balance between the PHREEQC Input and Output streams and separately, between the SysCAD Input and Output streams.

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options ElemBal... Tol.SigDigits Input Tol.Rel Input PHREEQC... ElementBalanceView If the Mass button is clicked, the elements will be shown in mass flow view.If the Mole button is clicked, the elements will be shown in mole flow view. Zeros If the Hide Zeros button is clicked, all elements that have NO mass flow will be hidden.If the Show Zeros button is clicked, all elements will be displayed, including those with zero mass flow. PHREEQC Element Balance (The following table displays the mass/molar flows, and absolute and relative errors of the individual elements.)The table has the following columns (one row for each element): FlowIn / Qm.In Display Visible when ElementBalanceView = Mass. The mass flow of the element in the PHREEQC Input stream. FlowOut / Qm.Out Display Visible when ElementBalanceView = Mass. The mass flow of the element in the PHREEQC Output stream. The QRxnBypass stream is also included in this total. This can be viewed by clicking "ShowQRxnBypass". AbsErr / Qm.Err Display Visible when ElementBalanceView = Mass. The difference in mass flow of the element between the PHREEQC Output and Input streams. FlowIn / QMl.In Display Visible when ElementBalanceView = Mole. The molar flow of the element in the PHREEQC Input stream. FlowOut / QMl.Out Display Visible when ElementBalanceView = Mole. The molar flow of the element in the PHREEQC Output stream. AbsErr / QMl.Err Display Visible when ElementBalanceView = Mole. The difference in molar flow of the element between the PHREEQC Output and Input streams. RelErr Display The relative difference in flow of the element between the PHREEQC Output and Input streams, relative to the Input stream. Scd... SysCAD Element Balance (The following table displays the mass/molar flows, and absolute and relative errors of the individual elements.)The table has the following columns (one row for each element): FlowIn / Qm.In Display Visible when ElementBalanceView = Mass. The mass flow of the element in the SysCAD Input stream. FlowOut / Qm.Out Display Visible when ElementBalanceView = Mass. The mass flow of the element in the SysCAD Output stream. The QRxnBypass stream is also included in this total. This can be viewed by clicking "ShowQRxnBypass". AbsErr / Qm.Err Display Visible when ElementBalanceView = Mass. The difference in mass flow of the element between the SysCAD Output and Input streams. FlowIn / QMl.In Display Visible when ElementBalanceView = Mole. The molar flow of the element in the SysCAD Input stream. FlowOut / QMl.Out Display Visible when ElementBalanceView = Mole. The molar flow of the element in the SysCAD Output stream. AbsErr / QMl.Err Display Visible when ElementBalanceView = Mole. The difference in molar flow of the element between the SysCAD Output and Input streams. RelErr Display The relative difference in flow of the element between the SysCAD Output and Input streams, relative to the Input stream.

### PhDeport tab page

This tab is only visible if PhaseElemDeportment is ticked. This tab shows the mass movement of elements for the Liquid, Solid and Gas phases.

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options PD... ElementBalanceView If the Mass button is clicked, the elements will be shown in mass flow view.If the Mole button is clicked, the elements will be shown in mole flow view. Zeros If the Hide Zeros button is clicked, all elements that have NO mass flow will be hidden.If the Show Zeros button is clicked, all elements will be displayed, including those with zero mass flow. PHREEQC.Liquid... PHREEQC Deportment (The following table displays the mass/molar flows, and absolute and relative changes of the individual elements.)The table has the following columns (one row for each element): FlowIn / Qm.In Display Visible when ElementBalanceView = Mass. The mass flow of the element in the liquid phase of the Input stream. FlowOut / Qm.Out Display Visible when ElementBalanceView = Mass. The mass flow of the element in the liquid phase of the Output stream. Change / Qm.Chng Display Visible when ElementBalanceView = Mass. The change in mass flow of the element between the liquid phase of the Output and Input streams. FlowIn / QMl.In Display Visible when ElementBalanceView = Mole. The molar flow of the element in the liquid phase of the Input stream. FlowOut / QMl.Out Display Visible when ElementBalanceView = Mole. The molar flow of the element in the liquid phase of the Output stream. Change / QMl.Chng Display Visible when ElementBalanceView = Mole. The difference in molar flow of the element between the liquid phase of the Output and Input streams. RelChange Display The relative change in flow of the element between the liquid phase of the Output and Input streams, relative to the Input stream. PHREEQC.Solid... PHREEQC Deportment (The following table displays the mass/molar flows, and absolute and relative changes of the individual elements.)The table has the following columns (one row for each element): FlowIn / Qm.In Display Visible when ElementBalanceView = Mass. The mass flow of the element in the solid phase of the Input stream. FlowOut / Qm.Out Display Visible when ElementBalanceView = Mass. The mass flow of the element in the solid phase of the Output stream. Change / Qm.Chng Display Visible when ElementBalanceView = Mass. The change in mass flow of the element between the solid phase of the Output and Input streams. FlowIn / QMl.In Display Visible when ElementBalanceView = Mole. The molar flow of the element in the solid phase of the Input stream. FlowOut / QMl.Out Display Visible when ElementBalanceView = Mole. The molar flow of the element in the solid phase of the Output stream. Change / QMl.Chng Display Visible when ElementBalanceView = Mole. The difference in molar flow of the element between the solid phase of the Output and Input streams. RelChange Display The relative change in flow of the element between the solid phase of the Output and Input streams, relative to the Input stream. PHREEQC.Gas... PHREEQC Deportment (The following table displays the mass/molar flows, and absolute and relative changes of the individual elements.)The table has the following columns (one row for each element): FlowIn / Qm.In Display Visible when ElementBalanceView = Mass. The mass flow of the element in the gas phase of the Input stream. FlowOut / Qm.Out Display Visible when ElementBalanceView = Mass. The mass flow of the element in the gas phase of the Output stream. Change / Qm.Chng Display Visible when ElementBalanceView = Mass. The change in mass flow of the element between the gas phase of the Output and Input streams. FlowIn / QMl.In Display Visible when ElementBalanceView = Mole. The molar flow of the element in the gas phase of the Input stream. FlowOut / QMl.Out Display Visible when ElementBalanceView = Mole. The molar flow of the element in the gas phase of the Output stream. Change / QMl.Chng Display Visible when ElementBalanceView = Mole. The difference in molar flow of the element between the gas phase of the Output and Input streams. RelChange Display The relative change in flow of the element between the gas phase of the Output and Input streams, relative to the Input stream.

### IPhDeport tab page

This tab is only visible if IPhaseElemDeportment is ticked. This tab shows the mass movement of elements for each PHREEQC phase.

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options IPD... ElementBalanceView If the Mass button is clicked, the elements will be shown in mass flow view.If the Mole button is clicked, the elements will be shown in mole flow view. Zeros If the Hide Zeros button is clicked, all elements that have NO mass flow will be hidden.If the Show Zeros button is clicked, all elements will be displayed, including those with zero mass flow. PHREEQC.... PHREEQC Deportment (The following table displays the mass/molar flows, and absolute and relative changes of the individual elements.)The table has the following columns (one row for each element): FlowIn / Qm.In Display Visible when ElementBalanceView = Mass. The mass flow of the element in the selected PHREEQC phase of the Input stream. FlowOut / Qm.Out Display Visible when ElementBalanceView = Mass. The mass flow of the element in the selected PHREEQC phase of the Output stream. Change / Qm.Chng Display Visible when ElementBalanceView = Mass. The change in mass flow of the element between the selected PHREEQC phase of the Output and Input streams. FlowIn / QMl.In Display Visible when ElementBalanceView = Mole. The molar flow of the element in the selected PHREEQC phase of the Input stream. FlowOut / QMl.Out Display Visible when ElementBalanceView = Mole. The molar flow of the element in the selected PHREEQC phase of the Output stream. Change / QMl.Chng Display Visible when ElementBalanceView = Mole. The difference in molar flow of the element between the selected PHREEQC phase of the Output and Input streams. RelChange Display The relative change in flow of the element between the selected PHREEQC phase of the Output and Input streams, relative to the Input stream.

### ParamSweep tab page

This tab is only visible if ShowPlotter is ticked. This option is only shown if this model has been successfully run.

This tab allows the user to perform multiple calculations to generate a set of data. The data can be copied and pasted into external programs such as Excel to allow the data to be plotted and analysed.

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options Use tools on this page to generate tabular data on clipboard from parameter sweep ParamSweep... Method AdjustT The chosen independent variable is Temperature. AdjustQMl The chosen independent variable is flow of an individual species. MinTemperature / MinT Input Only visible if Method = AdjustT. The minimum temperature of the final solution in the data set. MaxTemperature / MaxT Input Only visible if Method = AdjustT. The maximum temperature of the final solution in the data set. SelPhase... Filter Input Only visible if Method = AdjustQMl. Allows user to optionally shorten the Phase Selection list (SelPhase) by entering in some letters from the desired phase. PhaseFilter List Only visible if Method = AdjustQMl. List of available phases to choose from. The list will not show all phases if user has entered some letters in the Filter field above. SelSp... Filter Input Only visible if Method = AdjustQMl. Allows user to optionally shorten the Species Selection list (TargetSpAdjust) by entering in some letters from the desired species. TargSpAdjust List Only visible if Method = AdjustQMl. The user can select a single species from the list of all species in the PHREEQC database to have its flow varied. The list will be limited to those in the selected phase (SelPhase) and will not show all species if user has entered some letters in the Filter field above. MoleBasis Tickbox Only visible if Method = AdjustQMl. If this box is ticked, user specifies the minimum and maximum mole flow of selected species. If this is not ticked, user can specify these flows in terms of mass flow. MinSpMassFlow / MinSpQm / QmMin Input Only visible if Method = AdjustQMl and MoleBasis is not ticked. The minimum mass flow of the selected species in the final solution. MaxSpMassFlow / MaxSpQm / QmMax Input Only visible if Method = AdjustQMl and MoleBasis is not ticked. The maximum mass flow of the selected species in the final solution. MinSpMoleFlow / MinSpQMl / QMlMin Input Only visible if Method = AdjustQMl and MoleBasis is ticked. The minimum mole flow of the selected species in the final solution. MaxSpMoleFlow / MaxSpQMl / QMlMax Input Only visible if Method = AdjustQMl and MoleBasis is ticked. The maximum mole flow of the selected species in the final solution. StepSize Input The step size between each data point. If the user changes this value, then SysCAD will automatically adjust DataPoints (Below). (=(Max-Min)/(DataPoints-1)) DataPoints Input The number of calculations to perform/rows of data to generate. If the user changes this value, then SysCAD will automatically adjust StepSize (Above). (=(Max-Min)/StepSize + 1) IndVarRanges If the user clicks on this button, the inputs for the independent variable limits will be reset to their default values. (Applied to the temperature option only). PlotDataCreate If the user clicks on this button, SysCAD will perform the requested calculations based on the chosen parameters, to generate the required data. PlotDataTable If the user clicks on this button, SysCAD will perform the requested calculations based on the chosen parameters, to generate the required data. SysCAD will also copy the generated data to the clipboard, allowing it to be pasted into an external program such as MS Excel. Select Dependent Variables for Output SelectSpecies / SelectSp Tickbox Allows the user to select species to be reported. If this option is enabled, the SpForPlot tab will appear. ShowActCoeff / ShowAC Tickbox Only visible if the SelectSp option is available. If this option is enabled, the activity coefficients of the species selected on the SpForPlot tab will be reported. HideZeros Tickbox Only visible if the SelectSp option is available. If this option is enabled, the outputted table will be filtered so that only species which have a non-zero value in any of the calculations in the sweep will be shown in the table. SelectedSpCount Display Only visible if the SelectSp option is available. The number of species selected on the SpForPlot tab. Select Properties For Output PropertiesCount / PropsCount Input The number of properties to be included in the reported data set. PropX List The property to be reported from the list of available properties. Note: This field is only visible if the entry for NumPropsForOutput is greater then 0. If there is one property then X=1. If there are two properties, then X=1 and X=2, etc.

### SpForPlot tab page

This tab is only visible if the SelectSp option is enabled on the ParamSweep tab. It allows the user to select which species to be reported in the sets of data to be generated.

 Tag (Long/Short) Input / Calc Description/Calculated Variables / Options SpForPlot... SpeciesName The Species:Long or Short button is used to change the display of the Species names between the Short form, the Chemical compound, or the longer species names. SelectVisible User can select all the species which are currently visible in the access window. The ones that are visible may be limited by use of the Filter (see options below). UnselectVisible User can unselect all the species which are currently visible in the access window. The ones that are visible may be limited by use of the Filter (see options below). Filter View Filter This button will enable or disable the species filter options. ShowUnmapped(Only visible if Filter is enabled) Tickbox When enabled, all species will be displayed. When disabled, only species that are mapped to a SysCAD species will be shown. Phases(Only visible if Filter is enabled) All No filtering of species based on phase. Solids Only show solid phase species, hide other species. Liquids Only show liquid phase species, hide other species. Vapours Only show vapour (gaseous) phase species, hide other species. Solids & Liquids Only show solid and liquid phase species, hide other species. Solids & Vapours Only show solid and vapour (gaseous) phase species, hide other species. Liquids & Vapours Only show liquid and vapour (gaseous) phase species, hide other species. IPhase Only show "IPhase" individual phase species, hide other species. The individual phases shown will depend on the PHREEQC database chosen. Filters Display Always set to 'Content'. Content(Only visible if Filter is enabled) All No filtering of species based on element or name. Contains Any Element This will display all species that contain any of the elements entered in their elemental definition. Contains All Elements This will display only species that contain ALL of the elements entered in their elemental definition. Starts with ... This will display species that start with the text entered based on the short or long species tag depending on the current SpeciesTag selection. Contains any ... This will display species that contain the text entered in the currently displayed short or long species tag. Contains All ... This will display species that contain ALL the separate text entered in the currently displayed short or long species tag. Select Input Only visible if Filter is enabled and Content is NOT set to All. The user specified Elements or text to filter the species list. Refer to Species Filter for more information and examples. (The following tables (one per phase) display the PHREEQC species from the selected database. The user can select any number of species.)(Each table has the following column (one row per PHREEQC species):) Select Tickbox The properties (selected on the ParamSweep tab) of the selected species will be reported when the Generate function (ParamSweep tab) is used. SetAll...(displayed at the end of each phase) SelectAll User can select all the species in the relevant phase. UnselectAll User can unselect all the species in the relevant phase.

## Adding this Model to a Project

Insert into Configuration file

Sort either by DLL or Group.

 DLL: ScdPHREEQC.dll → Units/Links → PHREEQC: PHREEQC Evaporator or Group: Energy Transfer → Units/Links → PHREEQC: PHREEQC Evaporator

See Model Selection for more information on adding models to the configuration file.

Insert into Project

 Insert Unit → PHREEQC → PHREEQC Evaporator

See Insert Unit for general information on inserting units.

## Hints and Comments

1. The information in the VLE Section must be correct for the Evaporator to operate as required. If the VLE configuration requires information that is not available, then the flashing will not occur.
2. PHREEQC uses the SysCAD VLE submodel to perform flashing. Vapour-Liquid Equilibrium is not directly calculated by PHREEQC.