How Air Conditioning Work

Wednesday, January 7, 2009

COOLING TOWERS

- Cooling towers is a equipment that passes air over the water to remove the system heat from the water.
- Cooling towers are broadly divided into two type:

(1) The natural-draft or atmospheric tower, in which the air movement through the tower depends upon natural wind movement.
(b) The mechanical-draft tower through which air is drawn by fans.

Natural-Draft

-It's designed to cool water by means of air moving through the tower at the low velocities usually existing in open spaces.
-For this reason the roof of a building is an excellent location.
-These cooling towers should be so located that sufficient space is available all around the tower for free movement of air.
-Water returning from the condenser is sprayed down the tower through nozzles.
-The heat transfer from water to air is dependent upon the surface of water exposed to the air stream.
-Therefore for a good spray pattern, to produce as many fine droplets of water as possible, it is essential for good performance of the cooling tower.
-So clean nozzles are a must.
-Worn-out nozzles, scale or dirt in nozzles and piping, clogged strainers and pump impellers, all these can cause a reduction in the capacity of the cooling tower.

Mechanical-Draft

-The difference between this tower and the atmospheric type is that the draft in the mechanical-draft cooling tower is mechanically created by a fan.
-These are further classified as forced-draft or induced-draft towers.
-In the forced-draft, a fan forces the air up through the tower, while in the induced-draft type, a fan sucks the air through the tower.
-The return water from a condenser is fed into trough/troughs at the top of the cooling tower.
-Water is spread over the cooling tower area through orifices on the trough.
- Spray nozzles are seldom used.
- The towers are generally filled with a network of staggered wooden slats, to break the fall of the water over a larger surface.
-This provides more intimate contact with the air that is forced up through the cooling tower.
-The condenser water is cooled while the air is warmed and its vapor content is increased.
- The air leaves the tower in a nearly saturated condition.
-Eliminators have to be used to minimize the carry-over of entrained water in the air stream.

2 comments:

  1. Top 10 Cooling Tower Manufacturers India (Cooling Towers)– ABR Cooling, one of the leading cooling tower manufacturers in Delhi/NCR offers all type of cooling towers with mechanical & structural Spares.

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  2. Delhi, India Manufacturer and Supplier of Cooling Tower Fans, Frp airwashers, axil flow fans, cooling tower fan motor, cooling tower heat exchanger and etc. used to extracts heat from other materials, usually water.

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