Flooding valve trays

Klein [201] refers toThorngren [206, 207] but suggests that this proposed valve tray flooding is reasonably involved, although considered useful. 

Thorngren, J. T, Valve Tray Flooding Generalized, Hydrocarbon Processing 57, 8, (1978) p. 111. 

A conservative design would be to take 90% of the Glitsch value as the flooding load with Sin. bubble caps, and 70% of the valve-tray flooding load for a tray wifh 6 in. caps (Fractionation Research, Tulsa, Oklahoma, U.S.A., private communication). 

Thorngren, J.T. Valve tray flooding generalized. Hydrocarbon Process. 1978, 57 (8), 111-113. 

Downcomer Backup Flood. For downcomer backup. Equation 4 can be used. Reference 15 states that if the downcomer backup for valve trays exceeds 40% of tray spacing for high vapor density systems I3.01bs/ft-), 50% for medium vapor densities, and 60% for vapor densities... 

Kister and Haas [184] recommend using 25 dynes/cm in Equation 8-286 when the actual surface tension is a 25 dynes/cm. This correlation is reported [94, 184] to give better effects of physical properties, and predicts most sieve and valve tray entrainment flood data to 15 to 20%, respectively. 

Fair [183] relates sieve trays and includes valve tray remarks to the extensive work done for bubble cap trays. Figure 8-137 and 8-139 show flooding data for 24-in. spacing of bubble cap trays from [81] and represents data well for 36-in. diameter columns, and is conservative for smaller columns. Fair s work has been corrected to 20 dynes/ cm surface tension by ... 

Figure 13.34. Chart for finding the diameters of valve trays. Basis of 24 in. tray spacing and 80% of flood for nonfoaming services. Use Figure 13.32(b) for approximate adjustment to other tray spacings, and divide the Vload= V-J——— by the...

Figure 13.42. Efficiency of Glitsch V-l valve trays on isobut-ane/butane and cyclohexane/n-heptane as a function of vapor density and percent of flood, measured by Fractionation Research Inc. (Glitsch Inc., Bulletin 160, Dallas, TX, 1958).

A correlation for valve tray entrainment flooding that has gained respect and popularity throughout the industry is the Glitsch Equation 13 (Glitsch, Inc., Ballast Tray Design Manual, 6th ed., 1993 ... 

FIG. 14-30 Flood capacity of moving valve trays. (Courtesy ofKoch-Glitch LP.)... 

The jet flood equation is also based on the work of Souders and Brown [12]. This equation computes the ratio of the square power of the vapor load (noted in this chapter as Vload) to a constant, 8.75, to derive the tray flood. It has been used for over three decades by tray vendors (Koch and F.W. Glitsch [3]) to design and rate sieve-type trays. In many cases, especially for sieve-type tray design, jet flood governs tray flood and thus is the primary sieve tray design and rating equation. In contrast, Eqs. (3.88) through (3.90) are the principal equations for flood determination for both valve- and bubble cap-type trays. 

It was shown to predict most of the presently published sieve-tray and valve-tray entrainment flood data to within 15 and 20 percent, respectively. This is an improvement compared to the previous correlations above,... 

Flooding- mechanism Entrainment (jet) flood only Tray typee Sieve or valve trays only Pressure 1,5-500 psia (Note 1)... 

Valve trays. Manufacturer literature contains correlations for entrainment flooding (7-9). The three sieve tray correlations above are also applicable to valve trays. Of the three, the author recommends the Kister and Haas (15) correlation because it was specifically extended for valve trays and because it possesses the advantages listed above. When applying this correlation to valve trays, is the fractional hole... 

Figure 6.18 Flooding factor for sieve, bubble cap, and valve trays. From Ref. 52 with permission.

Capps [188] examines sieve and valve tray capacity performance and Figure 8-151 [188] is offered for preliminary colunm sizing or for determining whether a debottlenecking study is justified. The correlation for flooding, tray rating, and design of a tray are all based on the capacity factor, Cx, equation (Souders and Brown [68] by Capps [188]). 

Kister, H. Z. andj. R., Haas, Predict Entrainment Flooding on Sieve and Valve Trays, American Institute of Chemical Engineers, Chem. Eng. Aog. V. 86, No. 9 (1990), p. 63. 

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