Trays carbon-steel

Formex pro-cess, Snam-progetti /V-formyl-morph o-line (FM) water is added to the FM to increase its se-lectivity and also to avoid high reboiler temperatures during solvent recovery by distillation 40 perforated-tray ex-tractor, FM density at 1.15 aids phase separation low corrosion allows use of carbon steel equipment... 

Materials of construction Relative cost per ft of tray area (based on carbon steel = 1)... 

Tower shells may be ferrous, non-ferrous, stainless alloys or clad (such as monel-clad-steel). The trays are usually light gage metal consistent with the corrosion and erosion problems of the system. The velocity action of vapors flowing through holes and slots accentuates the erosion-corrosion problems, and often a carbon steel tower will use... 

Tray types are selected for performance. However, when a particular type is not specifically required, it is well to consider that, in carbon steel, the trays installed (not including tower shell) cost approximately ... 

One of the most frequent causes of flooding is the use of carbon steel trays. Especially when the valve caps are also carbon steel, the valves have a tendency to stick in a partially closed position. This raises the pressure drop of the vapor flowing through the valves, which, in turn, pushes up the liquid level in the downcomer draining the tray. The liquid can then back up onto the tray deck, and promote jet flood, due to entrainment. 

Rotary steam tube C = 3FA° eo, 500carbon steel, F= 1.75 for 304 stainless Cabinet dryer C = ). 5fpA0 77, 10[Pg.666]

Materials of construction. Due to the thin sheets of structured packings, their materials of construction need to have better resistance to oxidation or corrosion. For a service in which carbon steel is usually satisfactoiy with trays, stainless steel is usually required with structured packings. 

Section 6.5 because of the detailed design information now available. The costing was done in accordance with the recommendations of Mu let, Corripio and Evans (Ref. Al 3). Their method utilizes correlations for the cost of a simple carbon-steel structure. Factors are then applied to account for the cost of other materials, the inclusion of trays, for operating pressure, and for incidentals such as ladders and railings. The cooling circuit was costed on the basis of heat-transfer area using similar correlations. Details of the cost estimation calculations are included in Appendix G.5. 

A 25-tray distillation column, carbon steel, rated for 300 psig and 8-ft... 

Use 12Cr for valve trays and valves Sieve trays and stationary bubble cap trays may be made of carbon steel,... 

Costs for vessel (January, 1990—Including nozzles, manholes, and saddle or skirt but no special internals such as trays or agitators) as dollars per pound of weight of fabricated unit f.o.b. with carbon steel as the cost basis = 80O ) 0-34 where W is the total weight in pounds (applicable in Wv range of 800 lb to 100,000 lb). 

Lang factors to convert from the base cost of the delivered vessel (costed as if it were of carbon-steel material of construction so that weight becomes the primary measure of installation cost) to the cost of the vessel installed with all necessary auxiliaries except special internals such as trays or agitators are 3.0 for vessels installed in a horizontal position and 4.0 for vessels installed in a vertical position. 

FIGURE 8.11 Discharge coefficient for sieve-tray performance. Note Most perforated trays are fabricated from 14-gauge stainless steel or 12-gauge carbon-steel plates. 

Vacuum Tray Batch Dryers (carbon steel)... 

Tubular heat exchangers appear to have zero exponents, implyinig feftt direct labor cost is independent of size. This reflects the fact that s h equipment is set with cranes and hoists, which, when adequately sized for the task, recognize no appreciable difference in size of weight of the equipment. The higher labor exponent for installing carbon-steel towers indicates the increasing complexity of tower internals (trays, downcomers, etc.) as tower diameter increases. 

After filtration of the reactor outstream. the propane is extracted in a depropanizer and partly recycled. Excess benzene and cumene, which is obtained in a purity of 99.9 per cent weight, are recovered by distillation in columns with about 30 trays each. The cumene contains about 1200 ppm of impurities, usually consisting of 0.02 per cent weight ethylbenzene. 0.05 per cent weight n-propvlbenzene, and 0.05 per cent weight butyl benzene. The yield is 96 to 97 molar per cent in relation to benzene, and 91 to 92 per cent in relation to propylene. The fractionation section of the unit is of carbon steel In some cases, part of the reactor and other equipment may be of stainless steeL... 

Bubble-cap trays in the exdiange towers are made of stainless steel, preferably type 304 18-8. Carbon steel is unsuitable because the impingement of spray to which the trays are sulqected prevents an iron sulfide layer from forming, and under these conditions carbon steel conodes rapidly. The same ccmsiderations apply to other parts exposed to erosion by spray... 

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