In some places in industries, a lower temperature (compared to atmospheric) is required from process point of view or from comfort point of view. Air conditioning is out of question, as it would require large capital and huge running payment of electricity bills. Evaporative cooling is the solution in this case. This is just a scaled up model of home air coolers.
Working Principle Of Evaporative Coolers
Evaporative cooling is known to humanity since ages. Earthen clay pots have been providing coldwater during summer when there was no air conditioning or refrigeration. The fired clay pots have tiny holes through which water comes out and when it comes to surface, it evaporates. The heat required for evaporation is taken out from the water inside the pot. The heat transfer from the water is possible only because of the tiny passage in earthenware pots. The same principle is used in industrial evaporative coolers.
Air circulating fans draw air through a curtain of water. The water trickles down a path and during passage; water is broken down to tiny droplets giving it a large surface area. Air drawn through these tiny droplets and is cooled the same way as it happens in an earthen pot. The cold is circulated through the industrial installation. This gives installation an air which has a lower than atmospheric temperature. Evaporative cooling gives you comfortable atmosphere when outside is too hot to bear.
Advantages Of Evaporative Cooling
Advantage of evaporative cooling is the initial low cost and low operating costs. All that is required is the water pumps and the air circulating fans. The whole set up is compact. Evaporative cooling is the only method of removing large quantity of heat from cooling water used in many industrial plants. Here instead of removing heat from atmospheric air, heat from water is rejected to atmospheric air.
