Cooling towers fogging

Under certain conditions, the exhaust air of conventional mechanical draft cooling towers may form a fog plume, causing visibility and icing problems to highways and equipment. In cases where this cannot be tolerated, a combination wet/dry cooling tower is shown to be effective fog plume control method. The paper describes the basic phenomena of cooling tower fog formation. The operation and performance characteristics of the wet/dry tower are discussed as well as a method of select wet/dry design criteria. 11 refs, cited. 

Cooling Tower Fog Control and Abatement Veldhuizen, H. Ledbetter, J. 

Offsite Facilities/How to Prevent Cooling Tower Fog Campbell, J. C. 

In cold weather, water vapor exhausted from cooling towers condenses and fog is formed as a plume. What are one or two economically practical methods of preventing such cooling tower fog ... 

Cooling-Tower Plumes. An important consideration in the acceptabiHty of either a mechanical-draft or a natural-draft tower cooling system is the effect on the environment. The plume emitted by a cooling tower is seen by the surrounding community and can lead to trouble if it is a source of severe ground fog under some atmospheric conditions. The natural-draft tower is much less likely to produce fogging than is the mechanical-draft tower. Nonetheless, it is desirable to devise techniques for predicting plume trajectory and attenuation. 

Not only may the cooling-tower plume be a source of fog, which in some weather conditions can ice roadways, but the plume also carries salts from the cooling water itself. These salts may come from salinity in the water, or may be added by the cooling-tower operator to prevent corrosion and biological attack in the column. 

In places in which ground fog is undesirable, the dry-wet mechanical-draft cooling tower is the best solution. It will have its wet peaking tower out of service during the cooler months of the year, thereby substantially eliminating the fog problem and totally eliminating the icing problems of wet towers. 

The effect of condensation upon transfer rates with application to flue-gas washing plants and cooling towers are discussed. Theoretical models were developed for determining the rate of heat and mass transfer under conditions where fog formation prevails. Derived relationships are functions of the vapor and liquid equilibria and local heat and mass transfer of driving forces. They were used for a numerical study of the amount of fog formation as a function of the operational variables of a flue-gas washing plant in which the inlet gas temperature is typically... 

Fog and Ice Formation During Cooling Tower Operation Bach, H. 

Cooling Tower Plumes/Probabilities of Cooling Systein Fogging Decker, F. W. 

Where possible, cooling towers should be downwind from substations, pipe racks, and process equipment so that fog developed will not cause corrosion or obstruct vision. 

Processes involving coupled heat and mass transfer occur frequently in nature. They are central to the formation of fog, to cooling towers, and to the wet-bulb thermometer. They are important in the separation of uranium isotopes and in the respiration of water lilies. This chapter analyzes a few of these processes. Not unexpectedly, such processes are complex, for they involve equations for both diffusion and heat conduction. These equations are coupled, often in a nonlinear way. As a result, our descriptions will contain approximations to reduce the complexities involved. 

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