BATCHFRAC Run Until Conditions

Usage

Required entries include selecting the condition, entering its value, and specifying where it is to be evaluated.

Criterion

First select the desired type of condition. This activates all related data fields, if any. If appropriate, enter the corresponding value for the condition to be met.

The criterion types are:

Time: The policy segment ends when the total elapsed time since the beginning of the current policy segment reaches the specified value. Note that this is simulated distillation time, not elapsed computer time. Time may be selected in only one Run Until element in a policy segment.

Temperature: Segment calculations end when the specified temperature is reached; either in the stillpot, or on any stage in the column other than reboiler.

Amount: Segment calculations end when the specified amount is attained in either the stillpot or any of the accumulators.

Purity: Segment calculations end when the specified purity (of the specified components) is attained in either the stillpot or any stage. The purity of the liquid in the accumulator also may be specified.

Evaluated As

Select where the condition is to be evaluated. Only the options applicable to the selected condition will be available, as shown in the table:

Criterion Evaluated as Options

Amount Accumulator, Stillpot

Purity Accumulator, Stillpot, Stage (1 to N-1)

Temperature Stillpot, Stage (1 to N-1)

Component Selection

Press this button to display the BATCHFRAC - Component Selection window. Once the window opens, select the first and last component in the range for the condition. If the Criterion is Amount, all components are included by default (hence disabled). If Purity is selected, the component range must be supplied.

Approached From

This allows specifying that the condition is met only if approached from above or below. User must select one of the options. When amount is selected for any Accumulator contents, the user cannot select the Approach From buttons.

To change the dimensional units for entries shown on the screen, highlight the field of interest; then press the UOM button to open the Unit of Measure Selection Window.

How to get to this window

The BATCHFRAC - Run Until Conditions window is accessed by selecting Run Until in the Action/Condition table in the BATCHFRAC - Policy Segment window and then clicking on the linked text under Description.

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