Trays design, details

Figure 8-86 (page 139) is a 3-ft 0-in. diameter tray, and is representative of details associated with tray design.A typical 4-in. pressed cap is shown in Figures 8-79 and 81. 

Formulas and procedures for calculation of detailed tray specifications are presented, for example, by Glitsch Inc. (Bulletin 4900, Ballast Tray Design Manual, Dallas, TX, 1974), and illustrated with a completely solved numerical problem. 

Wafers are transported, in Inconel trays, on a moving belt through a reactant gas flow while being heated from below by quartz radiant heaters. Reactant gases are introduced through a unique disperser head design. Details of the gas introduction are shown in Figure 2. 

As stated in the introduction to Chapter 6, detailed tray layout is performed in the sscondary phase of tray design. A preliminary layout, however, is needed at the primary phase, because the layout influences column size. In the present example, the preliminary layout will be based on tray layout guidelines detailed in a companion book (1). 

Engineers will find detailed information on key fractionation concepts. .. column process design and shortcut calculations. .. tray design and operation. .. tray efficiency. .. packing design and operation. .. packing efficiency and scaleup. .. packing capacity and pressure drop. .. and much more. 

OTHER FACTORS. Design details of the column, such as vapor-opening dimensions, plate iayout, or the total number of trays can have an effect on the efficiencies. The exact influence of these factors is best determined by experimental tests. 

The column has 74 valve trays, the design details of which can be found in Example 11. The feed was introduced onto tray 37. 

Tray design is complex and design optimization involves many steps and decisions. Entire books have been written on the subject. The procedure here is for a general system with no special features. For those investigating the subject in detail the standard references are only a starting point for detailed discussions. 

Multiple factors influence tray efficiency. These include the physical properties of the system, operating conditions, vapor and liquid loads, compositions, tray type, fabrication details of the tray, and many others. A range of experimental studies have examined tray efficiency under different conditions. These studies show often conflicting results for the influence of the mechanical and process conditions involved. Study results reveal few useful engineering guidelines for tray design and efficiency. 

Summarizing, the details of the sieve-tray design are as follows ... 

Calculate some further details of the tray design 2... 

Technological details and operating characteristics of various types of plate columns are extensively discussed in textbooks on mass transfer (e.g., see Treybal [44]). The results of extensive research on bubble tray design is reported in the American Institute Chemical Engineers Bubble Tray Manual [45]. Flooding and weeping limits and further aspects of sizing are mentioned in a review by Zenz [5]. 

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