Cooling towers water loss

Figure 9-130. Atmospheric cooling tower water loss for various wind velocities. Used by permission of Plastics Technical Service, The Dow Chemical Co., Midland Mich, with data added from Fuller, A. L, et al. Chemical Engineering Progress, V. 53, No. 10 (1957) p. 501 all rights reserved.

Figure 12.13 illustrates severe damage suffered by a component of a cooling tower water pump. The jagged, undercut, spongelike metal loss characteristic of cavitation damage is apparent in Fig. 12.14. All damage occurred along the inner curvature of the specimen.

Loss of utilities including electrical power, steam, cooling tower water, instrument air, and nitrogen. 

These are instrument system loops that are necessary to avoid a failure which could result in nonreportable environmental releases, equipment or production losses, or reduced economic life, plus all other systems and alarms that assist operations that require prooftesting. These alarms and shutdown systems include refrigeration units that have less impact or safety or environmental issues than the Class 2 units, important pump shutdown alarms, low pressure utility alarms (well water, cooling tower water, natural gas, instrument air, nitrogen), and numerous low-pressure lubrication alarms. 

Despite this concern, some users of Ciass II cosolvent machines do not use chilled brine. Obviously, these users will experience reduced energy costs and required investment, and also experience increased costs of solvent loss. Certainly, chilled brine is not required for effective cleaning. In Table 1.5 is tabulated a comparison of cooling tower performance vs. that of mechanical refrigeration of "brine." The choice between chilled brine and cooling tower water is simply one of optimization. 

The utihty iadustry utilizes fans typically from 6.7—10 m diameter ia banks of 8 to 12 fans ia wet cooling towers. These towers cool the water used to condense the steam from the turbiaes. Many towers may be needed ia large plants requiring as many as 50 to 60 fans 12 m in diameter. These fans typically utilize velocity recovery stacks to recoup some of the velocity pressure losses and convert it to useful static pressure work. 

Performance, 387 Ground Area vs. Height, 391 Pressure Losses, 393 Fan Horsepower for Mechanical Draft Tower, 392 Water Rates and Distribution, 393 Blow-Down and Continuation Build-Up, 394 Example 915 Determining Approximate Blow-Down for Cooling Tower, 395 Pre-... 

Another complication that often arises is loss of water from the system. This could be, for example, the loss of water to effluent from a hosing operation or the evaporative loss to atmosphere from a cooling tower, neither of which becomes available for reuse. To illustrate how water losses can be accounted for, suppose that an operation is added to those in Table 26.5 with a maximum inlet concentration of 80 ppm and a flowrate of 10 t-h-1, all of which is lost. 

A Comparison of Evaporative Loss in Cooling Towers and in River Water Cooling... 

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