Pumparound Specifications
Every pumparound must have two defined conditions, or specifications, selected in this window.
Usage
From the Column Main Window, push the Pumparounds button.
From the Column Pumparounds Window, check the "Add Pumparounds" option.
Add pumparounds using the tabular input. Click on the various text strings to provide base information for the pumparound.
Click on the text string "two specifications" to access the Pumparound Specifications Window.
Select the desired "Specification" option to select the two conditions being specified. The choices are:
Rate and Duty : The Rate Specification and Duty Specification fields become available for input. For this option the pumparound return conditions (temperature and liquid fraction) are calculated by heat balance.
Rate Without Heater : The Rate Specification field becomes available. No other input is permitted.
Rate and Return Condition : The Rate Specification and Return Condition Specification fields become available for input. The duty for the associated heater/cooler is calculated by heat balance.
Duty and Return Condition : The Duty Specification and Return Condition Specification fields become available for input. The pumparound rate is determined with a heat balance.
The dimensional units for duties, rates, and return conditions may be changed by using the Unit-Of-Measure Selection Window which is displayed when the UOM button on the Toolbar is pushed.
Additional Information
Rate Specification
The "Total Pumparound" button is only available for columns using the Enhanced I/O and Sure algorithms. Total liquid pumparounds normally pump down to the tray below. If not there should be a cooling source or feed to that tray to provide reflux below the total pumparound draw. Similarly, a total vapor pumparound normally flows to the tray above. If not, a heating source or feed must be provided to that tray to create boil-up.
Return Condition Specification
Only one option may be selected for pumparounds for which a return condition is specified.
Duty Specification
A heater name is supplied for each duty for reference purposes. Convention for duties is minus for cooling and positive for heating.
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