Cooling towers: how to get peak efficiency.Cooling towers take hot (Condenser condenserDevice for reducing a gas or vapour to a liquid. Condensers are used in power plants to condense exhaust steam from turbines and in refrigeration plants to condense refrigerant vapours, such as ammonia and Freons. ) water and mix it with cold air to get colder water which returns to the Chiller chill·er n. 1. One that chills. 2. A frightening story, especially one involving violence, evil, or the supernatural; a thriller. chiller Noun 1. , picks up more heat and starts the cycle again. There are two types of Cooling towers used to cool water in commercial properties. The types are Cross Flow and Counter Flow. In the Cross Flow Tower, water flows by gravity through honey-combed Fill. Air flows perpendicular to the water, hence the name Cross Flow. Counter Flow Tower, the air moves upward through the fill as the water fall gravity, hence the name Counter Flow. Condenser water is pumped to the top of the tower, distributed of the tower and piped back to the chiller. Fans move the air through the tower fill and out of the tower. Some components of the Cooling Tower are: * Fill - Spreads the water into a very thin layer and allows the air to contact the water for as long as possible * Drift Eliminators - Material configured con·fig·ure tr.v. con·fig·ured, con·fig·ur·ing, con·fig·ures To design, arrange, set up, or shape with a view to specific applications or uses: to make air pass through changing direction enough times to remove the water picked up in the fill * Distribution System - The condenser water is distributed throughout the tower and broken up into small droplets * Fans - Must move air through the tower to achieve the correct change in the condenser water temperature Cooling Towers produce the desired results if air water produce the required heat transfer. This happens when the following are present: 1. Air a. Velocity through the Fill and Drift Eliminators must be slow as possible to keep the air in contact with the water for the greatest cooling. b. Fans in Cooling Towers are either centrifugal centrifugal /cen·trif·u·gal/ (sen-trif´ah-gal) efferent (1). cen·trif·u·gal adj. 1. Moving or directed away from a center or axis. 2. or propeller propeller, device consisting of a hub with one or more blades that propels a craft to which it is attached by rotating its blades in a fluid such as air or water. type 2. Water a. Flow to the tower should match the towers' capability. Too much does not allow the tower to cool it; too little does not allow for even distribution b. Distribution in the tower allows the water to be broken up into very small droplets so the air can mix and cool it. To increase the amount of heat transfer a Cooling, a process of Evaporative Cooling Evaporative cooling is a physical phenomenon in which evaporation of a liquid, typically into surrounding air, cools an object or a liquid in contact with it. Latent heat describes the amount of heat that is needed to evaporate the liquid; this heat comes from the liquid itself and , a process where some condenser liquid is changed to a vapor. To make this happen, it is necessary to add heat. The heat comes from the remaining liquid which is in turn cooled. Some ways to improve Cooling Tower Performance: 1. Distribute water and air over the complete heat transfer surface - check for blockages 2. Keep fans running rated conditions a. Adjust pitch of fan blades b. See that gear boxes or belt drives are in top condition 3. Keep pumps operating at peak efficiency 4. Chemically treat condenser water 5. Keep Cooling Tower clean 6. Add filtration filtration: see sewerage; water supply. Filtration The separation of solid particles from a fluidsolids suspension of which they are a part by passage of most of the fluid through a septum or membrane that retains most of the solids system to cut down on blockage blockage of intestine, urethra, etc. See obstruction under anatomical location, e.g. intestinal, urethral. blockage Wax, see there in piping condenser and chiller Remember that a Cooling Tower is a very good filter and it picks up and retains any of the dust in the air or the system. A recent concern associated with Cooling Towers is the amount of asbestos asbestos, mineral asbestos, common name for any of a variety of silicate minerals within the amphibole and serpentine groups that are fibrous in structure and more or less resistant to acid and fire. which was previously used in Towers. If these items are moved, extreme caution and qualified, experienced personnel should be used. To conclude, it is very important for money saving reason to have the Cooling Tower operate at its peal efficiency If problems are encountered, corrections should be performed by qualified people. |
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