Tower Internals

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They are perforated trays with small round holes. Vapor enters vertically through these holes and bubbles through the liquid, providing high efficiency at a low cost. The perforations on active Deck are typically ½” holes. The hole size may vary from 0.18” to 1” depending upon the application. Sieve Trays are conventional Trays with lower capacity than valve trays with similar efficiency. Sieve trays depend on vapor velocity to hinder liquid from falling through the perforations on the tray deck. Lower vapor velocity than design lets liquid flow through the perforations rather than into the downcomer. This condition is known as weeping. Where weeping is severe, the equilibrium efficiency will be very low. For this reason, sieve trays have a very small turndown ratio. Their standard operating range is 2:1 which can be extended to 2.5:1 with slightly higher pressure drop. At the other extreme, a very high vapour velocity leads to excessive entrainment of the upper tray and loss of tray efficiency. Sieve Tray design factors include the hole arrangement, quantity, and size. The number of holes and their size depends upon the vapor flow rate in the tower. Sieve trays are not too good in terms of Capacity, Flexibility and Fouling resistance.

Perforated plates with vertically moveable valves on the perforations. Some of the stagnant liquid section areas of the tray may have small directional fixed valves as well. These Trays have higher Turn Down than Sieve Trays. Since valves of different weights can be put on the perforations, these Trays have a bigger operating range with reduced tendency to weep. They offer more operational flexibility compared to fixed valve trays. By simple turn up or turn down of the vapor flow rate within a certain range, one may operate moving valve trays over a wide operating range. Their nominal turn down is 4:1.The Turndown performance of moving valve tray can be improved by installing valves in rows with alternating valve thickness. For eg one can put 14 ga and 16ga valves in alternate rows to improve Tray Turn  Down performance. They have acceptability for varied applications as they can be constructed with valves with different lifts (leg lengths). The moving valves can be circular or rectangular or circular caged valves, depending upon the need. These Trays are more prone to fouling than fixed valve trays because they have more surface area available for the deposition of contaminants.

Mesh Pad is a great Tower Internal device  for Mist elimination. We can provide various kinds of Mist Removers, depending upon the application.

Liquid Distributors play a very important role as a Tower Internal. Depending upon the application, a pipe OR gravity Distributor may be provided in various materials. The Figure here shows a Trough Baffle Distributor with side orifice in troughs. This is most suitable for a very low specific liquid rate. This distributor is equipped with integrated hold down grid. This distributor is equipped with high open area to minimize pressure drop. The distributor design consists of several troughs equipped with enhanced baffle plate. The trough walls are equipped with elevated distribution holes that feed onto a special liquid spreading baffle that is attached to it. The baffle spreads the liquid from each distribution hole into several streams feeding them in a controlled way onto the top of the packed bed. This drip point multiplier effect allows the use of larger holes within individual troughs, providing greater fouling resistance while achieving optimum liquid distribution quality even at very low liquid rates. The proposed distributor is equipped with pre-distributor parting box that receives the incoming liquid, reduces its momentum and feeds into individual troughs in proportion to area they are covering ensuring optimum distribution quality across entire operating range of liquid distributor. 

The packed bed will be equipped with GT-S101 Packing Support Grid.

We are quoting our GT-A10 deck type collector tray to collect the Rich TEG solution and transfer it to column boot in line with requisition documents.