Packed Column Design Outline

Designing a column usually starts with heat and material balance calculations, preferably using a computer simulation program. These calculations determine the liquid and vapor flow rates and the number of equilibrium stages required to meet the design performance specifications (separation, recovery, etc.). Fluid properties, such as densities and viscosities, may also be generated by the computer program. 

If the resulting ratio of packing size to column diameter is reasonable, an appropriate column diameter has been determined. Otherwise, the calculations are repeated with a new packing size. 

The next step is to determine the column packing height. The HETP is estimated using any of the methods described in Section 15.4.1. The column packing height is simply the number of equilibrium stages multiplied by the HETP. 

A check on the column height may be carried out based on mass transfer rate. This requires the availability of mass transfer coefficient data. Depending on appropriate assumptions. Equation 15.22 or 15.24, or their equivalent counterparts may then be used to calculate the column height, as discussed in Section 15.3. 

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The most important aspects of packed-column internals and their design are outlined in the following paragraphs. 

Related Calculations. Alternatively, a packed column can be considered for this separation. Its design should follow the procedure outlined in Example 8.4. 

This chapter examines common distributor and redistributor types and inlet arrangements used in packed columns, outlines the preferred practices, highlights consequences of poor practices, and supplies guidelines for troubleshooting and reviewing designs of distributors, redistributors, and feed and reflux inlets to packed towers. 

As expected from the design of the experiment, the HPLC column packed with CSP 14 containing all 36 members of the library with tt-basic substituents separated 7t-acid substituted amino acid amides. Although encouraging since it suggested the presence of at least one useful selector, this result did not reveal which of the numerous selectors on CSP 14 was the most powerful one. Therefore, a deconvolution process involving the preparation of series of beads with smaller numbers of attached selectors was used. The approach is schematically outlined in Fig. 3-17. 

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