Bubble trays

Fig. 26. Numbering plates and concentrations in a bubble tray column.

A general, approximate, short-cut design procedure for adiabatic bubble tray absorbers has not been developed, although work has been done in the field of nonisothermal and multicomponent hydrocarbon absorbers. An analytical expression which will predict the recovery of each component provided the stripping factor, ie, the group is known for each component on each tray of the column has been developed (102). This requires knowledge... 

Capacity Limitations. The fluid flow capacity of a bubble tray may be limited by any of three principal factors. 

E-factor for bubble tray gas load moles of component j gas flow rate flow rate of iaert gas... 

The once-mn tar acids are fractionated in three continuous-vacuum stills heated by superheated steam or circulating hot oil. These stills contain 40—50 bubble trays and operate at reflux ratios between 15 and 20 1. The overhead product from the first column is 90—95% phenol from the second, 90% (9-cresol and from the third, a 40 60 y -cresol—p-cresol mixture. Further fractionation gives the pure products. 

Sprudel-platte, /. bubble tray, -salz, n. Karlsbad salt, -stein, m. deposit from hot springs. Spruh-apparat, m. spraying or sprinklmg apparatus. -diise,/. spray nozzle, -elektrode, /. ionizing electrode. 

Column diameter for a particular service is a function of the physical properties of the vapor and liquid at the tray conditions, efficiency and capacity characteristics of the contacting mechanism (bubble trays, sieve trays, etc.) as represented by velocity effects including entrainment, and the pressure of the operation. Unfortunately the interrelationship of these is not clearly understood. Therefore, diameters are determined by relations correlated by empirical factors. The factors influencing bubble cap and similar devices, sieve tray and perforated plate columns are somewhat different. 

Although each plot must be for a specific system of conditions, Figures 8-102 and 8-103 are extremely valuable in analyzing the action of a bubble tray. 

A bubble tray blows when the vapor rate is extremely high, regardless of the liquid rate, causing large vapor streams or continuous bubbles to be blown through the liquid. The efficiency and contact is low and entrainment is usually high. Here also low slot seals contribute to the sensitivity of the tray to such action. 

A bubble tray cones when the liquid seal over the slot is low and the vapor rate is so high as to force the liquid completely away from the cap, thus bypassing the liquid entirely. Obviously, efficiency is unsatisfactory. The dynamic slot seals recommended in Table 8-18 normally will prevent such action. 

Tray spacing can usually be about 6 in. less than for a corresponding bubble tray. Sieve trays are operating on spac-ings of 9 in. and up to 30 in., the latter being necessary for high vacuum service. Spacing of 12-16 in. is common. 

Downcomers are designed for the same conditions as bubble tray towers. 

Figure 8-147 indicates minimum values of Fh to initiate acceptable bubbling tray action. Efficiency at this activation or load point might be expected to be low however Myers results indicate good values at this rate. 

American Institute of Chemical Engineers, Bubble Tray Design Manual, Prediction of Fractionation Efficiency, Amer. Inst. Chem. Engrs. (1958). 

Dauphine, T. C. Pressure Drops in Bubble Trays, Sc. D. Thesis, Mass. Inst. Technology (1939). 

Slurry reactors may take on several physical forms they may be simple stirred autoclaves they may be simple vessels fitted with an external pump to recirculate the liquid and suspended solids through an external heat exchanger or they may resemble a bubble-tray rectifying... 

AV reciprocating tachycardia, 5 108 Axial dispersion coefficient, 10 762 Axial dispersion/mixing, 10 762-763 in adsorption columns, 2 604 in bubble tray absorbers, 2 88-89 chromatographic adsorption, 2 610 in packed column absorbers, 2 61-65 Axial dissolved oxygen profiles, 25 707-708 Axial filtration, 22 385-386 Axial-flow angular-momentum flowmeter, 22 672-673... 

Bubbles, in fluidized beds, 11 805-806 Bubble size control, 11 805 in fluidized beds, 11 819, 821 Bubble size distribution, 12 14 in foams, 12 11 Bubble tear-offs, 20 229 Bubble tray absorbers, 1 27, 29 design, 1 83-86 Bubble-tube reactor, 25 194 Bubble tube viscometer, 21 739 Bubble two-phase theory of fluidization, 11 805-806... 

Krausening, in beer making, 3 584 Krebs cycle, 6 632-633 Kremser-Brown method, of bubble tray absorber design, 1 85 Kreysiginone, 2 91... 

Nonisothermal gas absorption in bubble tray absorbers, 1 86-87 in packed column absorbers,... 

Pebax, commercial block copolymer, 7 648t Pebble mills, 25 64 Pebble quicklime, 15 28 Peclet numbers (Pe), 2 63 10 763 22 746 25 686t, 687t 25 279. See also Mass transfer Peclet number (PeMT) axial dispersion in bubble tray absorbers, 2 89... 

Figure 12.17. Glitsch truss type bubble-tray in stainless steel for a 1.9 m absorption column...

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