Mechanical draught water cooling towers

Figure 13.13. Visco 2000 series steel framed, mechanical draught, water cooling tower...

INDUSTRIAL Water Society Guide to Mechanical Draught Evaporative Cooling Towers Selection. Operation and Maintenance (London, 1987). 

On the large scale, air and water are brought into countercurrent contact in a cooling tower which may employ either natural draught or mechanical draught. The water flows down over a series of wooden slats which give a large interfacial area and promote turbulence in the liquid. The air is humidified and heated as i( rises, while the water is cooled mainly by evaporation. 

Again as in Problem 13.8, the relation between enthalpy and temperature at the interface Hf vs. Of is drawn in Fig. 13b. It is seen that the operating line cuts the saturation curve, which is clearly an impossible situation and, indeed, it is not possible to cool the water to 285 K under these conditions. As discussed in Section 13.6.1, with mechanical draught towers, it is possible, at the best, to cool the water to within, say, 1 deg K of the wet... 

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