Proprietary valve tray design

Due to the need to use case-by-case analysis the Kister studies [136, 137] focused on item 1. The data evaluated came from published reports by Fractionation Research (FRI) and Separation Research Program (SRP) at the University of Texas, taken from commercial size equipment rather than laboratory research columns. The FRI data includes No. 2 and No. 2.5 Nutter random rings packing, aind Norton s Intalox 2T structured packing, each considered currently state-of-the-art or close to it, while the sieve and valve trays were of FRI s latest designs, plus Nutter s proprietary valve trays, all using 24-in. tray spacing. 

Valve trays are proprietary, and it is always best to have the manufacturer specify and design the tray layout. The amount of information available on valve tray design is limited, although some is available in manufacturers literature (138, 211, 307). 

Valve trays, because of their proprietary nature, are usually designed by manufacturers, although it is possible to obtain an estimate of design and performance from published literature 63 and from the methods summarised in Volume 6. 

Because of their proprietary nature, valve trays are usually designed by their respective vendors based on process specifications supplied by the customer. However, most fabricators publish technical manuals that make it possible to estimate some of the design parameters. The procedure for calculating valve-tray pressure drop outlined here has been adapted from the Koch Design Manual. As for the other column specifications required, they can be obtained via the same calculation procedures outlined above for the sieve-tray design. 

Manufacturers of valve trays, such as Koch-Glitsch, Inc., of Wichita, Kansas (Ballast trays and Flexitrays), and Sulzer-Chemtech (formerly Nutter Engineering Co.), of Tulsa, Oklahoma (Float Valve Trays), have prepared proprietary design manuals. Hence, only limited discussion will be given here. As for bubble-cap trays, design methods follow those for sieve trays. The vapor capacity chart (Figure 12.29) covers valve trays, as does the alternate method of Kister and Haas. Information on liquid entrainment is proprietary, but measurements have been made by Fractionation Research, Inc. Because of the vapor flow reversal, one would not expect entrainment from valve trays to be greater than that from sieve trays. Liquid capacity considerations follow exactly those for sieve trays. 

High capacity/high efficiency trays have valves or sieve holes oi bodi They typically achieve higher efficiencies and capacities by taking advantage of the active area under the downcomer. At this time, each ot the major vendors has its own version of these trays, and the designs arc proprietary. 

The lifeblood of engineering fabricators is their proprietary design manual, which contains formulas and graphs for calculating column parameters such as flooding, capacity, downcomer velocities, vapor capacity, tray diameters, column diameters, downcomer area, pressure drop, flow path width, tray layout, and cap, valve, or perforation size. Of key importance also are some of the other column internals such as ... 

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