Crossflow cooling tower

Another type of crossflow cooling tower is the wet-dry tower, which consists of a normal crossflow tower over which a few air coils are placed. The hot water is first cooled by an air cooled heat exchanger and then drops to the wet cooling tower where more cooling is obtained by the evaporative mechanism. Figures 5 and 6 provide examples. In contrast, deck-filled towers contain tiers of splash bars or decks to aid in the breakup of water drops to increase the total water surface and, subsequently, the evaporation rate. 

Analysis of a Multi-Unit Cocurrent Crossflow Cooling Tower... 

An analysis of multi-unit cocurrent crossflow cooling towers is made. Towers were placed in series and the results obtained were compared with that of multi-unit countercurrent crossflow cooling towers. The experimental data on the multi-unit cocurrent crossflow cooling tower were, analyzed in terms of enthalpy efficiency of single-unit, heat capacity ratio and number of transfer units. An outline of design calculations of multi-unit cocurrent crossflow cooling towers is presented. 4 refs, cited. 

Accurate Performance Testing of Crossflow Cooling Towers... 

An Analysis of Crossflow Cooling Towers. The Change in the Water Flow Rate is Considered... 

Cooling towers are broadly classified on the basis of the type of draft natural draft (natural convection), mechanical draft (forced convection) and mechanical and natural. Further distinction is made based on (1) the type of flow i.e. - crossflow, counterflow, cocurrent flow (2) the type of heat dissipation-wet (evaporative cooling), dry, wet-dry and (3) the type of application-industrial or power plant. Each of the major types of cooling towers has a distinct configuration. The major designs are summarized in Figures 1 through 8 and a brief description of each follows. 

Water quality is important, not only from an environmental point of view but also in relation to the type of packing to be specified. Analysis of the circulating water is simple to obtain, but it is very seldom offered to the cooling tower designer. The quality, or lack of it, will determine the type of pack to be used, the selection of structural materials and whether the tower should be induced or forced draft, counterflow or crossflow. Water treatment, in the shape of chemicals to control pH and to act as counter-corrosion agents or as biocides, all has a bearing on tower selection. 

Mechanical-draft cooling towers are normally supplied with either central baffles or inlet louvers. This depends on the tower dimensions. On these towers the wind or spray blowout is generally confined to relatively small singlecell units where an inlet may be provided on all four faces. In this case the major remedy is to provide internal diagonal baffles to prevent crossflow of air through the air inlets. 

Figure 9.18. Main types of cooling towers, (a) Atmospheric, dependent on wind velocity, (b) Hyperbolic stack natural draft, (c) Hyperbolic assisted with forced draft fans, (d) Counterflow-induced draft, (e) Crossflow-induced draft, (f) Forced draft, (g) Induced draft with surface precooler for very hot water also called wet/dry tower, [(fc)-(e) from Cheremisinoff and Cheremisinoff, 1981).

Increases in loading, cooling range and humidity all tend to improve cooling tower performance. Two basic types of hyperbolic towers are counterflow and crossflow, as shown in Figure 4.12. 

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