BATCHFRAC Policy Condenser

Specific information pertaining to the condenser is entered in this window. The condenser always is defined as a heat sink on stage one.

Usage

Check Define Condenser Specification for Policy box to override the condenser types in any policy. Select the desired condenser type from the following options. Once the Condenser Specifications are changed, that and the subsequent policies use the changed type of condenser. You cannot change condenser type for the first policy.

Bubble Temperature: This is the default condenser type and no data are required. The condenser temperature is computed such that the vapor entering the condenser is condensed to a bubble point liquid phase. Some liquid is returned to the column as reflux and some is fed to the accumulator.

When the policy type is "Total Reflux", condenser type is internally changed to Bubble Type.

Partial: The partial condenser corresponds to an equilibrium stage, with both equilibrium liquid and vapor produced from the reflux drum. All of the condensed liquid is returned to the top tray as reflux. The equilibrium vapor is not fed to the accumulator, but is withdrawn as the "overhead" product. The equilibrium vapor fraction is determined by the ratio of total distillate rate to top vapor (vapor entering condenser) rate. This condition also determines the condenser temperature.

When the policy type is "Total Reflux", condenser type is internally changed to Bubble Type.

Partial, Mixed: The mixed condenser may produce both vapor and liquid distillates. The equilibrium vapor is withdrawn as the "overhead" product. The liquid distillate is sent to the accumulator. The condenser operates at specified Vapor Fraction.

When the policy type is "Total Reflux", condenser type is internally changed to Bubble Type.

Subcooled, Fixed Temperature: For this option the column top vapor is condensed and usually cooled below its bubble point or "subcooled". You must provide a value for the Fixed Temperature. If the temperature specified is above the bubble temperature for any part of the distillation, the condenser will operate at the bubble point for that part. You can specify Subcooled condenser even to a Total Reflux type of policy.

Fixed Temperature

This entry must be supplied for the Subcooled, Fixed Temperature condensers. Users may change the dimensional units by using the Unit-Of-Measure Selection Window, which is displayed when the UOM button on the Toolbar is pushed.

Distillate Vapor Fraction

This entry is required to specify the Partial, Mixed condenser.

Distillate Vapor Fraction Basis

The vapor fraction basis can be mass or mole (default).

Limitations:

How to get to this window

The BATCHFRAC- Policy Condenser window is accessed by pressing the Condenser button on the BATCHFRAC Policy Segment window.

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