When cooling water in cooling towers, the more surface contact of water with air, the more favorable conditions for heat transfer. Contact with air, water and an increase in the surface of this contact is achieved in various ways. Cooling towers can be classified mainly by the method of supplying air to the water and the type of irrigation device. By way of supplying air coolers are divided into three main groups: the first – fan cooling tower through which air is pumped injection wells or suction fan, the second – Cooling towers, which creates a high thrust air exhaust tower. third – open or atmospheric cooling tower in which to air flow through them using the wind force and partly by natural convection. Depending on the construction of the irrigation device and method, which is achieved by increasing the contact surface water and air, cooling towers are subdivided into film, drip and bryzgialnye. Each of these types of cooling towers can have very different types and designs of individual elements of irrigators, their different sizes and distances between them, and be made of various materials. Cooling towers hold sectional or stand-alone – odnoventilyatornymi, the plan has the shape of a rectangle, square, polygon or circle.
Cooling towers allow for higher thermal loads and provide better cooling of the water due to the increased relative (to water flow) of air flow passing through the cooling tower. On cooling towers may be the specific heat load of 90-120 thousand W/m2 80-100 thousand kcal / (h * m2) and above, while, for example, Cooling towers, other things being equal, these loads do not exceed 90 Thousands W/m2 80 thousand kcal / (h * m2). For atmospheric cooling towers maximum heat load is 35-60 thousand W/m2 30 – 50 thousand kcal / (h * m2). The dependence of the cooling effect of atmospheric cooling tower of strength and direction of the wind limits their application. With fan coolers chilled water temperature obtained at 4-6 (in some cases, 2-3 ) above the air temperature wet bulb, with turret towers – at 8-10 . With the "dry" (radiator) cooling towers chilled water temperature can be obtained just above the air temperature dry bulb. Replacement of cooling air economical only in the case of cooling a product with a high initial temperature to temperature about 20 higher than the dry bulb temperature. The value of temperature drop of water in cooling towers is assigned depending on the temperature of incoming water in cooling towers, which, in turn, determined by the manufacturing equipment that uses water as coolant.
On cooling towers is possible to achieve a temperature difference of water to 25 C or more (depending on the initial temperature of the water). In practice, the use of tower cooling towers (for example, in thermal power plants), the maximum temperature drop of water is 8-10 . Cooling towers provide a more sustainable given cooling water, and more maneuverable than the tower, control its temperature. Jobs fan coolers are more easily amenable to automation to maintain chilled water temperature at a given level. Cooling towers require smaller area of development in comparison with other water cooler, while achieving the same cooling effect. In comparison with the cooling towers they operate at lower water pressure. Construction of the fan cooling towers are cheaper by 50-80% than the tower, and by 30-50% than the spray pond.