Tray Installation

Install trays, junction boxes, and outlet boxes... 

Installing trays and junction boxes Laying wire on trays Making connections on both the motor and MCC sides Ringing" out system... 

Factor to remove trays to install packing 0.1 times cost of new hardware Factor to remove packing to install trays 0.07 times cost of new hardware... 

Figure 10.8 Incorrectly installed tray panels cause inadequate downcomer sealing (a) Correct (6) incorrect. Courtesy of Scott W. Golden, Glitsch Inc., private communication.)...

Vertical towers for absorption, distillation, and stripping utilize trays (plates) and/or packing. Mulct et al. (1981b) present a method for estimating the purchase cost of trays installed in a vertical tower. This cost is added to Eq. (16.52) to obtain the total purchase cost. The cost for the installed trays, Cj, all with downcomers, is given by... 

Install tray decks fitted with venturi openings. This will reduce tray AP. 

Of course, these sorts of design dimensions are meaningless unless both the weirs and bottom edge of the downcomers are level. So inspect the installed trays for weir and downcomer levelness. 

Also, I ll inspect the installed trays to assure myself that the downcomer itself is not too flexible at its bottom edge. This is a good application for downcomer bracing brackets. 

No, that s not possible," I replied, as I had personally inspected the installed trays and approved the tower as ready for closure. No, the trays were designed and installed properly They must have been damaged on start-up. I advised that we should now order new replacement trays. We should shut down the debutanizer as soon as the replacement trays arrived. 

Nonisothermal Gas Absorption. The computation of nonisothermal gas absorption processes is difficult because of all the interactions involved as described for packed columns. A computer is normally required for the enormous number of plate calculations necessary to estabUsh the correct concentration and temperature profiles through the tower. Suitable algorithms have been developed (46,105) and nonisothermal gas absorption in plate columns has been studied experimentally and the measured profiles compared to the calculated results (47,106). Figure 27 shows a typical Hquid temperature profile observed in an adiabatic bubble plate absorber (107). The close agreement between the calculated and observed profiles was obtained without adjusting parameters. The plate efficiencies required for the calculations were measured independendy on a single exact copy of the bubble cap plates installed in the five-tray absorber. 

Ethylbenzene Separation. Ethylbenzene [100-41-4] which is primarily used in the production of styrene, is difficult to separate from mixed Cg aromatics by fractionation. A column of about 350 trays operated at a refluxTeed ratio of 20 is required. No commercial adsorptive unit to accomplish this separation has yet been installed, but the operation has been performed successhiUy in pilot plants (see Table 5). About 99% of the ethylbenzene in the feed was recovered at a purity of 99.7%. This operation, the UOP Ebex process, requires about 40% of the energy that is required by fractional distillation. 

Design Methods for Turbo-Tray Dryers The heat- and mass-transfer mechanisms are similar to those in batch tray diyers, except that constant turning over and mixing of the solids significantly improves diying rates. Design must usually be based on previous installations or pilot tests by the manufacturer apparent heat-transfer... 

FIG. 14-81 Fabricated costs and installation time of towers. Costs are for shell with two beads and sldrt, but without trays, packing, or connections. (Peters and Timmerhatis, Plant Design and Economics for Chemical Engineers, 4th ed., McGraw-Hill, New Yoik, 1991. )... 

Removal factor for removing trays to install new trays ... 

Tray active panels installed with valves under downcomer of tray above. Limited capacity. High and unstable pressure drop at moderate rates. Installation and inspection error. 

Trays from one section installed in wrong section. Limited capacity. High pressure drop. Flooding in restricted section. Installation error. 

Sieve trays installed with holes behind false downcomer. Entrained liquid overhead. Limited lean oil flow. Vessel manufacturer error. 

Manways left off trays. Poor separation. Everything looked good. Scan interpretation did not identify problem until after the tower was opened. In fact, the trays with properly installed manways were thought to be entraining. Installation error. 

Leaving tray support rings in towers revamped with packed beds. Poor separation. Premature flooding. Installation error. There are too many examples of this for us to continue to make this one. If you are not confident enough to remove the tray support rings, don t pack the tower. 

Installing the standard antijump baffles for certain inboard downcomer trays to keep droplets (produced by tray blowing ) from entering the downcomer. 

Solution The sparger (feedpipe) w as turned so that the holes w ere on top rather than the bottom. This ensured that the sparger remained full of liquid even at low feed rates. A deflector w as installed above the orifices to keep feed from impinging on the tray above. This solution w as... 

The cost,, of the stripper (including installation and auxiliaries, but excluding the sieve trays) is given by... 

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