Chimney tower

Hyperbolic (chimney towers)—counterflow or cross-flow... 

Commonly, amine absorbers include an integral gas. scrubber section in the bottom of the tower. This scrubber would be the same diameter as required for the tower. The gas entering the tower would have to pass through a mist eliminator and then a chimney tray. The purpose of this scrubber is to remove entrained water and hydrocarbon liquids from the gas to protect the amine solution from contamination. 

This tower depends upon natural draft action the same as a chimney to draw cool air in at the bottom and expel it out the top as warm moist air (Figure 9-101). The action of the tower depends upon the atmospheric temperature therefore, on a hot day the action of the tower may be less than on a cool day. These towers are relatively large, and require power for pumping the water to a point in the tower which is usually lower than for an atmospheric tower. There are no fan costs. Units have been built 310 ft high, base diameter 210 ft and a throat of 120 ft, wdening to 134 ft in diameter at the top [30]. 

Chimney-assisted natural draft towers are of hyperboloidal shapes because they have greater strength for a given thickness a tower 250 ft high has concrete walls 5-6 in. thick. The enlarged cross section at the top aids in dispersion of. exit humid air into the atmosphere. 

As a result, the tower flooded above the holddown plate. To fix this problem, the packing holddown was dropped 15 in below the chimney, orifice plate, distributor. As a result, the tower fractionated properly. 

Fan power consumption is the major operating cost and can be counterbalanced in part by greater investment in natural draft construction. In the majority of process applications, fen-operated towers are preferred. Very large installations such as those in power plants employ chimney assisted natural draft installations. A limited use of atmospheric towers is made in areas where power costs are especially high. 

As noted, two principles of heat transfer are involved evaporation and convection. The rate of heat transfer by both convection and evaporation increases with an increase in air-to-water interfacial surface, relative velocity, contact time and temperature differential. Packing and fill in a tower serve to increase the interfacial surface area the tower chimney or fans create the relative air-to-water velocity and contact time is a function of tower size. These three factors all may be influenced by the tower design. 

In an atmospheric spray tower the air movement - is dependent on atmospheric conditions and the aspirating effect of the spray nozzles. Natural-draft cooling tower operation depends on a chimney or stack to induce air movement. Mechanical-draft cboling towers utilize fans to move ambient air through the tower. Deck-filled towers contain tiers of splash bars or decks to assist in the breakup of water drops to increase the total water surface and subsequently the evaporation rate. Spray-filled towers depend only on spray nozzles for water breakup. Coil shed towers are comprised of a combination structure of a cooling tower installed on top of a substructure that contains atmospheric section coils. Hyperbolic natural-draft cooling towers are typically large-capacity systems. 

These depend on a chimney or stack to induce air movement through the tower (Figure 4.3). 

The paper presents a method for the rational design of reinforced concrete chimneys or cement silos, towers for warm liquids and cooling towers subject to the effects of thermal gradients. The loads acting on the structure are divided into general loads and local loads. The effects of these loads on the concrete, the vertical reinforcement, and the horizontal (annular) reinforcement are studied with the aid of tables to obtain the significant stresses. A numerical example is given. 8 refs, cited. 

The efficient operation of the distillation, or fractionating, tower requires the rising vapors to mix with the liquid on each tray. This is usually achieved by installing a short chimney on each hole in the plate and a cap with a serrated... 

The chemistry laboratories, designed by the chemist Vernon Harcourt, did not open until 1889. Martha Whiteley (see Chap. 3), a chemistry student at RHC at the time, noted "... there were only four science students, and no laboratories. They used three rooms in the North Tower, which to this day have sinks and taps in them, and did Chemistry, Physics or Botany according to the way the wind blew, because one chimney always smoked. 53 Student life at RHC was very regimented in the early years, as one student, a Miss Dabis, recounted in 1888 ... 

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