Column internals constructions

Packed Columns A packed column is constructed from glass, stainless steel, copper or aluminum and is typically 2-6 m in length, with an internal diameter of 2-4 mm. The column is filled with a particulate solid support, with particle diameters ranging from 37-44 pm to 250-354 pm. 

Capillary Columns Capillary, or open tubular columns are constructed from fused silica coated with a protective polymer. Columns may be up to 100 m in length with an internal diameter of approximately 150-300 )J,m (Figure 12.17). Larger bore columns of 530 )J,m, called megabore columns, also are available. 

The column operation is gravity induced, with the heavier liquid flowing downward and the lighter liquid flowing upward by buoyancy. For the process to be workable, it is therefore required that one liquid phase be of a distinctly higher density than the other. The internal construction of an extractor column could be of several types, including trayed columns, packed columns, or spray columns with or without agitation. 

Table 2.6 shows the applications and the materials typically used. It is clear from the table that fluoropolymers are used principally for barriers (linings) and other applications such as column internals, seals and gaskets. In rare situations they are used to construct self-supporting stmctures. 

Construction supervisors should be made aware of the functions of column internals and of any unique requirements of the service. For instance, if leakage is to be minimized, the construction crew should be made well aware of this need. They should also be alerted to the common installation traps that deserve specific attention (Sec. 10.9). 

A detailed review of existing equipment s design and construction drawings will also provide insights into various equipment and plot limitations. For example, increased feed rate, improper internals and level controls can adversely affect a separator s efficiency. A review of these details in the existing separators will be very useful for revamp projects. Similarly, careful review of column internal details is required to check possible modification to increase capacity/efficiency and reduce flooding/weeping. 

Hong, X.H. 2013. Discussion on Column internal force and beam-column joint design of concrete column and light steel roof structure. Fujian Construction Science Technology 2 31-33. 

A. Column Internals. The analogy of brine softening to water softening does not extend to mechanical design. The systems used to soften water are not suitable for our application, where exposure conditions are quite different. More robust construction is necessary. While chemical compatibility with brine is essential, it is not the only consideration. Mechanical and thermal stability is also important. Distortion of a distributor or collecting screen, for example, can allow loss of resin or channeling of fluid. 

Figure 18.17 Details of Internal Construction of a Distillation Column (From S. Walas, Chemical Process Equipment Selection and Design. Boston, MA Butterworths, 1988. Reprinted with permission.)...

As indicated in Table 3.3, the mass transfer coefiicient in the Sherwood group Sh is not only affected by the geometry of equipment and internal construction, such as the dll ratio or the ratio of column diameter to packing size, but also the fluid properties such as p, p, a in the dimensionless group. 

A1.3.1 Azobenzene Percolation Column, glass constructed from 12.0-mm outside diameter and 6.0-mm outside diameter standard glass tubing with a reservoir of approximately 125 mL near the top. The top of the column shall be a female spherical ground-glass joint. The bottom of the cblumn has a stopcock with internal metering valve attached by means of a standard taper joint. The entire percolation assembly is illustrated in Fig. 3. 

Analytical Columns The most commonly used columns for HPLC are constructed from stainless steel with internal diameters between 2.1 mm and 4.6 mm, and... 

The carbon bed can be supported by glass wool, wire cloth, etc. Columns and fixtures can be constructed from glass, plastic, reinforced fiberglass, or metal. Borosilicate glass is commonly used. It is essential that all columns used in the pilot system have at least the same internal diameter. 

Distillation column, tray absorber Diameter, height, internal pressure, material of construction, tray type, number of trays, condenser, reboiler (see item 3)... 

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