This article details  upon the new developments and upgraded process of cooling tower.
 Cooling towers are a very important part of many industries. The primary task of a cooling tower is to reject heat into the atmosphere. They represent a relatively inexpensive and dependable means of removing low-grade heat from cooling water with the help of atmospheric air by evaporative cooling. The make-up water source is used to replenish water lost to evaporation. Hot water from heat exchangers is sent to the cooling tower. The water exits the cooling tower and is sent back to the exchangers or to other units for further cooling.
Cooling towers fall into two main categories: Natural draft and mechanical draft.
Natural draft towers use very large concrete chimneys to introduce air through the media. Due to the large size of these towers, they are generally used for water flow rates above 45,000 cu.m. per hour. These types of towers are used only by utility power stations.
Mechanical draft towers utilise large fans to force (in forced draft cooling tower) or suck air (in induced draft cooling tower) through circulated water. The water falls downward over fill surfaces, which help increase the contact time between the water and the air – this helps maximise heat transfer between the two.Cooling tower size is affected by the flow, range (hot water temperature minus cold water temperature), approach (cold water temperature minus wet bulb temperature) and wet bulb temperature. When three of these four quantities are held constant, tower size increases in the following manner:

Directly with the flow
Directly with the range
Inversely with the approach
Inversely with the inlet wet bulb temperature.
Mechanical draft towersMechanical draft towers are available in two airflow arrangements: induced draft cooling tower; and forced draft cooling tower. Accordingly to direction of air flow cooling tower are further classified as follows:

Counter flow induced draft.
Cross flow induced draft.
In the counter flow induced draft design, hot water enters at the top, while the air is introduced at the bottom and exits at the top.  In cross flow induced draft towers, the water enters at the top and passes over the fill. The air, however, is introduced at the side either on one side (single-flow tower) or opposite sides (double-flow tower). An induced draft fan draws the air across the wetted fill and expels it through the top of the structure.
Mechanical draft towers are available in a large range of capacities. Normal capacities range from approximately 10 tonnes, 2.5 cu.m. per hour flow to several thousand tonnes and cu.m. per hour. Towers can be either factory built or field erected.
Many towers are constructed so that they can be grouped together to achieve the desired capacity. Thus, many cooling towers are assemblies of two or more individual cooling towers or cells. Multiple-cell towers can be lineal, square, or round depending upon the shape of the individual cells and whether the air inlets are located on the sides or bottoms of the cells.
Components of cooling towerThe basic components of an evaporative tower are: Frame and casing, fill, cold water basin, drift eliminators, air inlet, louvers, nozzles and fans.
Frame and casing: Most towers have structural frames that support the exterior enclosures (casings), motors, fans, and other components. For some smaller designs, such as some glass fibre units, the casing may essentially be the frame.Fill: Most towers employ fills (made of plastic or wood) to facilitate heat transfer by maximising water and air contact. Fill can either be splash or film type. With splash fill, waterfalls over successive layers of horizontal splash bars, continuously breaking into smaller droplets, while also wetting the fill surface. Plastic splash fill promotes better heat transfer than the wood splash fill. Film fill consists of thin, closely spaced plastic surfaces over which the water spreads, forming a thin film in contact with the air. These surfaces may be flat, corrugated, honeycombed, or other patterns. The film type of fill is the more efficient and provides same heat transfer in a smaller volume than the splash fill.
Cold water basin: The cold water basin, located at or near the bottom of the tower, receives the cooled water that flows down through the tower and fill. The basin usually has a sump or low point for the cold water discharge connection.
Drift eliminators: These capture water droplets entrapped in the air stream that otherwise would be lost to the atmosphere.
Air inlet: This is the point of entry for the air entering a tower. The inlet may take up an entire side of a tower–cross flow design– or be located low on the side or the bottom of counter flow designs.

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This article details  upon the new developments and upgraded process of cooling tower.
 Cooling towers are a very important part of many industries. The primary task of a cooling tower is to reject heat into the atmosphere. They represent a relatively inexpensive and dependable means of removing low-grade heat from cooling water with the help of atmospheric air by evaporative cooling. The make-up water source is used to replenish water lost to evaporation. Hot water from heat exchangers is sent to the cooling tower. The water exits the cooling tower and is sent back to the exchangers or to other units for further cooling.
Cooling towers fall into two main categories: Natural draft and mechanical draft.
Natural draft towers use very large concrete chimneys to introduce air through the media. Due to the large size of these towers, they are generally used for water flow rates above 45,000 cu.m. per hour. These types of towers are used only by utility power stations.
Mechanical draft towers utilise large fans to force (in forced draft cooling tower) or suck air (in induced draft cooling tower) through circulated water. The water falls downward over fill surfaces, which help increase the contact time between the water and the air – this helps maximise heat transfer between the two.Cooling tower size is affected by the flow, range (hot water temperature minus cold water temperature), approach (cold water temperature minus wet bulb temperature) and wet bulb temperature. When three of these four quantities are held constant, tower size increases in the following manner:

Directly with the flow
Directly with the range
Inversely with the approach
Inversely with the inlet wet bulb temperature.
Mechanical draft towersMechanical draft towers are available in two airflow arrangements: induced draft cooling tower; and forced draft cooling tower. Accordingly to direction of air flow cooling tower are further classified as follows:

Counter flow induced draft.
Cross flow induced draft.
In the counter flow induced draft design, hot water enters at the top, while the air is introduced at the bottom and exits at the top.  In cross flow induced draft towers, the water enters at the top and passes over the fill. The air, however, is introduced at the side either on one side (single-flow tower) or opposite sides (double-flow tower). An induced draft fan draws the air across the wetted fill and expels it through the top of the structure.
Mechanical draft towers are available in a large range of capacities. Normal capacities range from approximately 10 tonnes, 2.5 cu.m. per hour flow to several thousand tonnes and cu.m. per hour. Towers can be either factory built or field erected.
Many towers are constructed so that they can be grouped together to achieve the desired capacity. Thus, many cooling towers are assemblies of two or more individual cooling towers or cells. Multiple-cell towers can be lineal, square, or round depending upon the shape of the individual cells and whether the air inlets are located on the sides or bottoms of the cells.
Components of cooling towerThe basic components of an evaporative tower are: Frame and casing, fill, cold water basin, drift eliminators, air inlet, louvers, nozzles and fans.
Frame and casing: Most towers have structural frames that support the exterior enclosures (casings), motors, fans, and other components. For some smaller designs, such as some glass fibre units, the casing may essentially be the frame.Fill: Most towers employ fills (made of plastic or wood) to facilitate heat transfer by maximising water and air contact. Fill can either be splash or film type. With splash fill, waterfalls over successive layers of horizontal splash bars, continuously breaking into smaller droplets, while also wetting the fill surface. Plastic splash fill promotes better heat transfer than the wood splash fill. Film fill consists of thin, closely spaced plastic surfaces over which the water spreads, forming a thin film in contact with the air. These surfaces may be flat, corrugated, honeycombed, or other patterns. The film type of fill is the more efficient and provides same heat transfer in a smaller volume than the splash fill.
Cold water basin: The cold water basin, located at or near the bottom of the tower, receives the cooled water that flows down through the tower and fill. The basin usually has a sump or low point for the cold water discharge connection.
Drift eliminators: These capture water droplets entrapped in the air stream that otherwise would be lost to the atmosphere.
Air inlet: This is the point of entry for the air entering a tower. The inlet may take up an entire side of a tower–cross flow design– or be located low on the side or the bottom of counter flow designs.

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