Wind tower

For land-based wind farms, once the wind towers are installed, the land area around them can be used for other purposes, such as agricultural use. 

Other issues include concerns over the visual impact of the wind towers, the noise they make and their impact on birds. 

Transport Determined from a Network of Wind Towers, NOAA Technical Memorandum ERLTM-ARL 25 (1970). 

The use of wind towers dedicated to produce electricity for water and CO2 co-electrolysis to afford products (Fig. 39.1) is an interesting alternative. 

Cooling Towers. The cooling tower location relative to the prevailing wind direction should be such that the wind hits the short side or the side perpendicular to the inlet louvers. This helps balance the air flow to the two inlet sides. 

Plant layout and noise suppression material are two general noise abatement methods. Plant layout does not affect noise levels at any given point however, noise can be abated by screening off a section of the plant. An example of this is to orient cooling towers with their closed faces toward the critical location. This method must also consider wind direction to balance air draft. Tankage can be located to act as a noise screen. 

Thermal turbulence is turbulence induced by the stability of the atmosphere. When the Earth s surface is heated by the sun s radiation, the lower layer of the atmosphere tends to rise and thermal turbulence becomes greater, especially under conditions of light wind. On clear nights with wind, heat is radiated from the Earth s surface, resulting in the cooling of the ground and the air adjacent to it. This results in extreme stabihty of the atmosphere near the Earth s surface. Under these conditions, turbulence is at a minimum. Attempts to relate different measures of turbulence of the wind (or stability of the atmosphere) to atmospheric diffusion have been made for some time. The measurement of atmospheric stabihty by temperature-difference measurements on a tower is frequently ntihzed as an indirect measure of turbulence, particularly when climatological estimates of turbulence are desired. 

Seed hairs from the grass formed, matured, and were carried by the wind into the basin of the cooling tower. 

Tower This may be tubular or lattice type to mount the mill s mechanism. The structural design is based on the cutout wind speed. 

Measurements of wind, turbulence, and temperature aloft may also be made at various heights on meteorological towers taller than 10 m. WTiere possible, the sensors should be exposed on a boom at a distance from the tower equal to two times the diameter of the tower at that height. 

The use of a measurement generally dictates the circumstances of data collection. For example, to provide a best estimate of plume transport direction, hour by hour, of a release from a 75-m stack, a wind vane at the 100-m level of a tower will probably provide more representative wind direction measurements than a vane at 10 m above ground. If the release has buoyancy so that it rises appreciably before leveling off, even the 100-m measurement may not be totally adequate. 

Windage The loss of water through the air-intake louvers as a result of malfunctioning of the wind cheek walls in the lower section of the tower. 

Wind Load Design Criteria Wind load criteria for design of structure, buildings, towers, etc, and their parts shall conform with the requirements of the... 

Normal recirculation in average installations for forced draft may run 3-10% of total inlet air, and 1-8% for induced draft towers, all depending upon the location and wind conditions during any day or season. Some towers can be arranged to have less than 1% recirculation. If conditions are suspected of being conductive to recirculation, it should definitely be allowed for in design of the tower. Recirculation increases the wet bulb temperature of entering air, increases the total air required (and hence size of... 

The evaluation of atmospheric and natural draft towers has not been completely presented in the detail comparable to mechanical draft towers. Some data are available in estimating form, but the evaluation of transfer rates is only adequate for estimating purposes [4]. The design of such towers by the process engineer must be made only after due consideration of this, and ample factor of safety should be included. Figure 9-130 presents general information on water loss due to wind on the tower. 

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.

The rate of evaporation from a cooling tower is approximately 1 per cent of the circulation rate for each 5°C drop in temperature across the tower, or about 7 liters/h per ton of refrigeration. Windage losses will obviously depend on the prevailing wind conditions and the design of the tower with regard to spray elimination but, typically, these are about 0.2 per cent of the circulation rate. 

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. 

On larger multi-celled mechanical-draft towers of both counterflow and crossflow variety, the air inlets are confined to the two opposing faces and windage or drift loss is unlikely to occur, except under exceptionally high wind conditions. Here again, remedial work, depending upon the location, can be applied but at additional cost (see Figure 34.10). 

Limit the tower height to about 175 ft max because of wind load and foundation considerations. An additional criterion is that L/D be less than 30. 

Cooling towers should be sited so that under the prevailing wind the plume of condensate spray drifts away from the plant area and adjacent properties. 

Different snow and ice making systems have been tested. The first years both fan type snow guns and one LowEnergyTower were used. The fan-type machines required a lot of maintenance and surveillance the first years and a lot of the snow from the LowEnergyTower landed outside the storage. The last year s two fan type snow guns have been used, mounted on 5 m high towers and now only operated in the wind direction. This worked well. 

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