Tower internals

Tower Internals and Equipment Modification. Tower capacity expansion can be achieved through the use of random or stmctured packing, or through the use of higher capacity trays such as the UOP multiple downcomer tray. Packing has been used in the gasoline fractionator, water quench tower, caustic and amine towers, demethanizer, the upper zone of the deethanizer, debutanizer, and condensate strippers. Packing reduces the pressure drop and increases the capacity. 

Pressure at the pulsing device and the conditions for cavitation and water hammer may be estimated by the methods of Wilhams and Little [Trans. Jnst. Chem. Eng. (London), 32, 174 (1954)] provided the pressure-drop characteristics of the tower internals are known. Jealous and Johnson (loc. cit) have had good success in computing the power required for pulsing. Since power requirement alternates, the use of a flywheel on the pulse mechanism to act as an energy reservoir is suggested as a means of reducing power requirements. Alterna-... 

With respect to selecting measurements, emphasis should include measurements within the equipment such as tower internal temperatures and compositions, internal reac tor conditions, and intermediate exchanger temperatures in multipass exchangers. Trace component compositions provide particular insight into distillation-column performance. Those components that fall between the heavy and light keys and distribute in the products can usually be described by a variety of models and parameter estimates They provide little insight into the column performance. 

Kitterman, Layton, Tower Internals and Accessories, paper presented at Congresso Brasileiro de Petro Quimiea, Rio de Janeiro, November 8-12, 1976. 

TOWER INTERNALS SPECIFICATIONS TRAY TYPE COLUMNS... 

Figure 8-156B. Tower internals specifications form, tray type columns.

Deviations from optimal design of trays, packings and other tower internals, e.g., distributors and baffles. 

Note 25 Intalox , Norton = app. 1-in. size 40 Intalox , Norton = app. lJ4-in. size 50 Intalox , Norton = app. 2-in. size See Figure 9-22 for C, s. tower internals. 

Figure 9-74B. Tower internal specifications, Spray or Packed Columns.

Revamp the tower internals with high-capacity trays or packing. 

AREA = total tower internal cross-sectional area, ft2 DC = side downcomer width dimension, in DCAREA = side downcomer area, ft2... 

Separation equipment tends to have less flexible design limits and can be costly to modify. For example, the C02 absorber and solvent regenerator towers in a wet scrubbing unit are difficult to replace. Fortunately, it is often possible to make changes to tower internals, or to change the solvent composition, to provide more capacity86. 

The bottoms pressure is usually selected to permit use of a readily available heating medium (steam or hot oil), as well as to stay below a temperature that could cause product degradation. In the ECH-EB system, degradation is not considered a problem, and column bottoms pressure is solely a function of the pressure drop across the tower internals. Because, as seen in step 1, relative volatility can vary appreciably with pressure, it is advantageous in this case to install low-pressure-drop, high-efficiency tower internals. 

PROCESS DESIGN SECTION TOWER INTERNALS CORPORATE ENGINEERING DATA SHEET ... 

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. 

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