Ion Exchange (INX) Column Washing

General Description

The main objective of this operation is to estimate the time and volume of solution required for washing a column.

Unit Procedure Availability

      Ion Exchange Procedure (for Demineralization)

INX Column Washing: Modeling Calculations

The user has flexibility in specifying any of the following combinations: Washing Time and Flowrate, Time and Volume, or Volume and Flowrate. Further, there is considerable flexibility in specifying the flowrate and volume. Note that these quantities correspond to the solution that is consumed in a single column per cycle.

Solution Volume Calculation

The wash solution volume is equal to the bed volume of the column times the volume factor (in packed bed volumes) that is specified by the user. Since the flowrate of a wash stream is adjusted by the model, the user must make sure that the composition of the stream is correct and not worry about the total stream flowrate.

Process Time Calculation

When the user specifies the Approach Velocity (also known as Linear Velocity), the process time is calculated using the following equation:

ColumnFeedProcessTime00781.jpg 

eq. (A.166)

The feed (wash) volume in the above equation is expressed in ‘packed bed volumes’.

Material Balances

All materials used for washing a column end up in a waste stream.

INX Column Washing: Interface

The interface of this operation has the following tabs:

      Oper. Cond’s, see INX Column Washing: Oper. Conds Tab

      Labor, etc, see Operations Dialog: Labor etc. Tab

      Description, see Operations Dialog: Description Tab

      Batch Sheet, see Operations Dialog: Batch Sheet Tab

      Scheduling, see Operations Dialog: Scheduling Tab