Classifier

From SysCAD Documentation
Jump to navigation Jump to search

Navigation: Models ➔ Mass Separation Models ➔ Classifier


General Description

The classifier mixes perfectly all the incoming feed streams and then, based on the user configuration, calculates the amount, temperature and composition of material reporting to the products.

Diagram

Models-Classifier-image001.gif

The diagram shows the default drawing of the Classifier, with all of the streams that are required for operation of the unit. The physical location of the streams connecting to the unit is unimportant. The user may connect the streams to any position on the unit.

Inputs and Outputs

Label Required
Optional
Input
Output
Number of Connections Description
Min Max.
Feed 1 Required In 1 20 The slurry feed to the Classifier
Overflow Required Out 1 1 The classifier overflow.
Underflow Required Out 1 1 The classifier underflow.
Vent Optional Out 0 1 Vent Stream (Vapour only)

Behaviour when Model is OFF

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

  • The field MassFracToUF becomes visible and the user may set the fraction of the feed stream that reports to the 'Underflow' outlet. The default is 100%.
  • All streams connected to the unit will flow out of the 'Underflow' outlet, unless the user has changed the above field from 100%. In which case the user defined fraction of the feed will report to the Overflow stream;

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

Model Theory

The Classifier is based on user defined variables that define the solids / liquids split. There are three methods available in this model:

  1. UFSolRec User specified feed solids recovery and underflow solids concentration.
  2. OFConc User specified underflow and overflow solids concentrations.
  3. UFVolFlow User specified underflow solids concentration and volume flowrate.

Flowchart

The following shows the sequence of events if sub model options are switched on. See next heading for more information.

Models-Classifier-Image002.gif

Data Sections

The default access window consists of several sections,

  1. Classifier tab - Contains general information relating to the unit.
  2. PC - Optional tab that is visible if EB.Solubility.On and/or EB.PhaseChange@T.On is enabled in the Evaluation Block.
  3. RB - Optional tab, only visible if the Reactions are enabled.
  4. EHX - Optional tab, only visible if the EnvironHX is enabled.
  5. Evap - Optional tab that is visible if Evaporator is enabled.
  6. MU - Optional tab, or multiple tabs if more than 1 Makeup is selected. Only visible if one of more Makeups are enabled in the Evaluation Block.
  7. DB - Optional tab, or multiple tabs if more than 1 Discard Block is selected. Only visible if one of more Discard Blocks are enabled in the Evaluation Block. Only available in Build 138 or later.
  8. QFeed - Optional tab, only visible if ShowQFeed is enabled. This page shows the properties of the mixed stream as the feed to the unit. If user has specified a required pressure in the unit, the mixed feed will be set to this pressure. This may cause the temperature of the mixture to change if the delta P is significantly different.
  9. QUF - Only available in Build 139 or later. Optional tab, only visible if ShowQUF is enabled. This page shows the properties of the Underflow stream. The tags in the QUF tab are valid even when the ShowQUF option is not selected.
  10. QOF - Only available in Build 139 or later. Optional tab, only visible if ShowQOF is enabled. This page shows the properties of the Overflow stream. The tags in the QOF tab are valid even when the ShowQOF option is not selected.
  11. Info tab - Contains general settings for the unit and allows the user to include documentation about the unit and create Hyperlinks to external documents.
  12. Links tab, contains a summary table for all the input and output streams.
  13. Audit tab - Contains summary information required for Mass and Energy balance. See Model Examples for enthalpy calculation Examples.

Classifier Page

Unit Type: Classifier - 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 Tick Box This allows the user to enable or disable the unit. If the unit is disabled, no reactions will occur and the field MassFracToUF becomes visible.
MassFracToUF_WhenOff / MassFracToUF Input This field is only visible if the On tickbox is NOT ticked. This field allows the user to specify the fraction of the incoming streams that will flow to the classifier underflow when the unit is disabled.
Method UFSolRec User specifies the required feed solids recovery to the underflow and underflow solids concentration at 25°C.
OFConc User specifies the required underflow and overflow solids concentration at 25°C.
UFVolFlow User specifies the required underflow volume flowrate and solids concentration at 25°C.
The visibility of the variables below will depend on method selection above.
SolidsToUF Input The required percentage of the feed solids reporting to the underflow, this is the underflow solids recovery.
UFSolidConc25Reqd Input The required underflow solids concentration measured at 25°C.
OFSolidConc25Reqd Input The required overflow solids concentration measured at 25°C.
UFQv25Reqd Input The required underflow volumetric flowrate measure at 25°C.
OperatingP - NOTE: this pressure is applied to the (combined) feed, before sub-models (if any).
Method AutoDetect If there are any liquids AND no vapours present in the feed, outlet streams will take the highest pressure of the feeds. Else (eg. some vapours present) outlet streams will take the lowest pressure of the feeds.
LowestFeed Outlet streams will take the lowest pressure of the feeds.
HighestFeed Outlet streams will take the highest pressure of the feeds.
Atmospheric Outlet streams will be 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 Outlet streams will be at the user specified pressure.
IgnoreLowMassFlow / IgnoreLowQm Tick Box This option is only visible if the AutoDetect, LowestFeed or HighestFeed methods are chosen. When calculating the outlet pressure and temperature of the tank, SysCAD will ignore the low flow feed streams should this option be selected. The low flow limit is set in the field below.
LowMassFlowFrac / LowQmFrac Input This field is only visible if the IgnoreLowQm option is selected. This is the amount any stream contributes to the total flow. For example, if the total feed to the tank is 10 kg/s, and this field is set to 1%. Then any feed streams with less than 0.1 kg/s will be ignored in the pressure calculations.
PressureReqd / P_Reqd Input This field is only visible if the RequiredP method is chosen. This is user specified pressure.
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).

EB (Flow Evaluation Block)

Solubility.On Tickbox Only visible if Solubility has been defined for at least one species in the project and Plant Model - Soluble Tab - Global.Solubility = OFF. Allows the user to switch on any predefined solubility curve to adjust the composition of material in the unit.
PhaseChange@T.On Tickbox Only visible if Phase Change at Temperature has been defined for at least one species in the project and Plant Model - Species Tab - PhaseChange@T = OFF. Allows the user to switch on any predefined phase changes at temperature in the unit.
EvalSequence Calc The sequence in which the sub models (which are part of the evaluation blocks) will be calculated. The sequence is determined by the priority selection for the individual sub-models.
Note: If the user chooses On-AutoSequence then SysCAD will determine the sequence of the sub-models. The auto evaluation sequence followed will be the order the sub models are listed below.
Makeups Input The number of Makeup Blocks required. Extra dropdown options Makeup1, Makeup2, etc will be added to allow these to be switched on and off and prioritised in relation to the other sub-models.
MakeupX List This can be used to switch the Makeup Block (MU) on or off and prioritise it in relation to the other sub-models. If this is 'On' then the associated page, MUX becomes visible and may be configured.
Note: This field is only visible if the entry for 'Makeups' is greater than 0. If there is one makeup then X=1. If there are two makeups, then X=1 and X=2, etc.
Reactions List Reaction Block (RB) - Enable or disable Reactions and set the sequence in relation to the other sub-models. If this is 'On' then the associated page, RB becomes visible and may be configured.
Note: The user does not have to configure a reaction file, even if this block is checked.
EnvironHX List Environmental Heat Exchanger (EHX) - Enable or disable Environmental Heat Exchange and set the sequence in relation to the other sub-models. If this is 'On' then the associated page, EHX becomes visible and may be configured.
Note: The user does not have to configure an environmental heat exchange, even if this block is checked.
Evaporation List Evaporation Block (Evap) - Enable or disable the Evaporator and set the sequence in relation to the other sub-models. If this is 'On' then the associated page, Evap becomes visible and may be configured.
Note: The user does not have to configure an evaporator, even if this block is checked.
Discard Input Only available in Build 138 or later. The number of discard blocks required. Extra dropdown options Discard1, Discard2, etc will be added to allow these to be switched on.
DiscardX List Only available in Build 138 or later. This can be used to switch the Discard Block (DB) on or off and prioritise it in relation to the other sub-models. If this is 'On' then the associated page, DBX becomes visible and may be configured.
Note: This field is only visible if the entry for 'Discards' is greater than 0. If there is one discard then X=1. If there are two discards, then X=1 and X=2, etc.

Residence Time

ResTime...
Calc Tickbox Allows the user to specify the volume of the unit, from which a residence time can be calculated.
Volume Input Only visible if the Calc option has been enabled. The operating volume of the unit. This will be used to calculate the apparent residence time in the unit. This is based on the volumetric flow of all outlets from the unit.
MassFlow / Qm Calc Only visible if the Calc option has been enabled. The mass flow of material from the unit.
Temperature / T Calc Only visible if the Calc option has been enabled. The temperature of the material leaving the unit.
Slurry Calc Only visible if the Calc option has been enabled. The residence time of the slurry in the unit.
Total Calc Only visible if the Calc option has been enabled. The residence time for the slurry and the vapours in the unit. If there are any vapours leaving the unit, then this value will be smaller than the Slurry figure.

Options

ShowQFeed Tick Box QFeed and associated tab pages (eg Qm) will become visible, showing the properties of the combined feed stream. See Material Flow Section. This will be prior to any sub-model (eg reactions) actions.
showQUFTickbox Only available in Build 139 or later. When selected, the QUF and associated tab pages (eg Sp) will become visible, showing the properties of the Underflow stream. See Material Flow Section. Tags in the QUF tab can be used for controllers (eg: PGM files) and reports even when this option is not selected.
showQOFTickbox Only available in Build 139 or later. When selected, the QOF and associated tab pages (eg Sp) will become visible, showing the properties of the Overflow stream. See Material Flow Section. Tags in the QOF tab can be used for controllers (eg: PGM files) and reports even when this option is not selected.
TrackStatus Tick Box Allows warning messages be displayed if requirements are not met.

Slurry Separation Results

UFSolidsRecovery Display The fraction of feed solids sent to the underflow.
UFLiquidRecovery Display The fraction of feed liquid sent to the underflow.
VapourMassFlow / VQm Calc Only available in SysCAD 9.3 Build 137 or later. The total flow of vapour to the Underflow and Overflow streams. (This does NOT include the vapour to the Vent)
The following table displays the flows and compositions of the Underflow stream. Note: This for slurry only, vapours are excluded.
UF.MassFlow / UF.Qm Calc The total mass flow of the Underflow stream.
UF.VolFlow / UF.Qv Calc The total volume flow of the Underflow stream.
UF.SolidMassFlow / UF.SQm Calc The solids mass flow in the Underflow stream.
UF.LiquidMassFlow / UF.LQm Calc The liquid mass flow in the Underflow stream.
UF.SolidFrac / UF.Sf Calc The solids mass fraction in the Underflow stream.
UF.LiquidFrac / UF.Lf Calc The Liquid mass fraction in the Underflow stream.
UF.Temperature / UF.T Calc Temperature of the Underflow stream.
UF.Density / UF.Rho Calc The total density of the Underflow stream.
UF.SolidConc Calc The solid concentration (mass of solids/density of slurry) of the Underflow stream.
UF.SolidConc25 Calc The solid concentration at 25°C (mass of solids/density of slurry at 25°C) of the Underflow stream.
The following table displays the flows and compositions of the Overflow stream. Note: This for slurry only, vapours are excluded.
OF.MassFlow / OF.Qm Calc The total mass flow of the Overflow stream.
OF.VolFlow / OF.Qv Calc The total volume flow of the Overflow stream.
OF.SolidMassFlow / OF.SQm Calc The solids mass flow in the Overflow stream.
OF.LiquidMassFlow / OF.LQm Calc The liquid mass flow in the Overflow stream.
OF.SolidFrac / OF.Sf Calc The solids mass fraction in the Overflow stream.
OF.LiquidFrac / OF.Lf Calc The Liquid mass fraction in the Overflow stream.
OF.Temperature / OF.T Calc Temperature of the Overflow stream.
OF.Density / OF.Rho Calc The total density of the Overflow stream.
OF.SolidConc Calc The solid concentration (mass of solids/density of slurry) of the Overflow stream.
OF.SolidConc25 Calc The solid concentration at 25°C (mass of solids/density of slurry at 25°C) of the Overflow stream.
GridDisplay Tick Box This is a global selection, if this is selected, then where available, variables will display in a table format, if not selected, they will be listed in separate groups as a single list.

Adding this Model to a Project

Insert into Configuration file

Sort either by DLL or Group.

  DLL:
Separation.dll
Units/Links Separation: Thickener - Classifier
DLL:(Build135 or earlier)
Separ1.dll
Units/Links Separation: Thickener - Classifier
or Group:
Mass Separation
Units/Links Separation: Thickener - Classifier

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


Insert into Project

  Insert Unit Separation Thickener - Classifier

See Insert Unit for general information on inserting units.