Cooling Tower ?
A cooling tower is a structure specially built to reject excessive and waste heat into the atmosphere. Cooling towers are heat exchangers where air and water are brought into direct contact with each other so as to expel the excessive heat out. As this action takes place in the best cooling tower, a small amount of water gets evaporated; this helps in reducing the amount of heat present in the water.
This heat rejection device, cooling tower rejects the waste heat present in the water to the atmosphere by cooling a water stream at a lower pressure. Cooling tower can either use the process of evaporation of water to remove heat from water or the process used in closed circuit dry cooling tower that are based on cooling of air to lower the temperature.
FRP Cooling Tower
There is a type of cooling tower, the FRP Cooling tower that is the best cooling tower structure for smaller cooling towers. The FRP Cooling tower (Fiber Reinforced Plastic) is known for its capability to resist corrosion. FRP Cooling tower has become one of the most common and best cooling tower structural materials for small cooling towers.
Process of Heat Rejection in Cooling Tower
The most common type of heat rejection process used in the best cooling tower is the ‘evaporative technique’ that allows a small amount of water to evaporate after cooling the water stream. This heat evaporated from the water stream is transferred to the air stream present in cooling tower that raises the temperature of the air and its relative humidity by 100%, and then this air is finally discharged to the atmosphere. Cooling tower are an evaporative heat rejection device that are commonly used to lower the water temperatures better than the ones achieved with air cooling or dry heat rejection devices such as the radiator of the car. Therefore the technique of using the best cooling tower is cost-effective and energy efficient for cooling. The cooling potential of a cooling tower is immense and cannot be ignored.
Cooling towers have two types of rejection equipment: direct (open circuit) and indirect (closed circuit). The most common, popular and best cooling tower is an open direct contact rejection device but there is another one that is the closed circuit cooling tower which too is a cooling tower.
An open circuit(direct) cooling tower is an enclosed structure that has external means to distribute the warm water supplied to it over a packing like the labyrinth or fill. This fill provides an expanded air-water interface for heating of the air as well as the evaporation process. The water is cooled as it falls down by the force of gravity while being in direct contact of the air that passes over it. This cooled water is later collected in a water basin that is exactly below the fill from there it is pumped back through the process to absorb more heat and this heat is finally released into the air.
The closed circuit (indirect) cooling tower functions without any direct contact of the air and the fluid being cooled. Unlike the open circuit cooling towers, the indirect cooling tower has two different fluid circuits. One circuit is external where the water is re-circulated on the outside of the second circuit that is composed of tube bundles which are further connected to the hot fluid that being cooled and later returns in a closed circuit. Air is finally drawn out through the re-circulating water that is outside the hot tubes, helping cooling water vapors to evaporate to the opening of the cooling tower.
Common Application of Cooling Tower
The cooling tower can be installed for various applications, but following are the most common applications of the best cooling towers by Kool Drop Cooling Tower Pvt. Ltd.:
- Cooled water for air-conditioning
- Electric power generation
- Cooled water for the circulating water in:
- Oil Refineries
- Chemical Plants
- Petrochemical Plants
- Thermal Power Stations
ROUND TYPE COOLING TOWER
WELLTECH manufactures frp round bottle shape cooling towers based on induced draft counter flow design using rotary water distribution system using aluminium/ ss / gun metal sprinkler
Casing (F. R. P.)
The F. R. P. cooling tower casing has sufficient strength to adequately withstand wind velocities up to 60m/sec. (134 mph), earthquakes and vibrations.
Water Basin (F. R. P.)
The water basin like the tower casing is made of FRP. It is bowl shaped, with a cylindrical auxiliary suction tank at the bottom. This construction eliminates the danger of drawing air into the pump when operating with minimum water in the basin. A drain is provided to facilitate the removal if accumulated dirt from the bottom of the tank. The bowl shape of the water basin facilitates the cleaning of the tower interior.
The fillings are made of PVC. They have excellent heat exchange efficiency and remarkably good chemical resistance. These fills are totally enclosed in the tower, thus excluding them from sunlight and minimizing the growth of algae .
A pre-eminent quality and long life fill consists of modular block of PVC honey combs construction to create prolonged contact time of hot air with water for maximum heat transfer.
TECHNICAL DATA OF PVC FILLS
|1||Standard Type of PVC Fills||: 600 mm X 300 mm X 150 mm|
|2||PVC Honey Combs||: 25 mm (12.5 + 12.5)|
|3||Corrugation Pitch||: 2.8 mm|
|4||Corrugation Depth||: 3 mm|
|5||Spiral Angus||: 21|
|6||No. of PVC sheets per 150 mm width||: 12|
|7||Heat Transfer area / Cu Ft fill vol.||: 1 Cu Ft.|
|8||Thickness of finished fill||: 0.25 mm|
The sprinkler consists of four PVC sprinkler pipes screwed into a rotating bead and is mounted on the top of the stand pipe mounted centrally in the tower. The sprinkler assembly rotates at 5 to 7 RPM by reaction force from the circulating water which is discharged at low pressure out of holes along the sprinkler pipes. The sprinkler pipes require a water head loss of only 2 meters to give the necessary rotation. As the sprinkler pipes are screwed into the rotary head and secured by threaded lockouts the specified revolution speed can be maintained by adjusting the sprinkling angle in accordance with the flow of water.
Special design consideration has been given to the rotary sprinkler head with respect of corrosion, abrasion assembling. The sprinkler head is made of aluminum alloy and fitted with ball bearings to take thrust and radial loads. These bearings ensure that the sprinkler head revolves smoothly even with reduced circulation water flow.
Spirally bound Drift Eliminator is made of PVC it is designed to reduces drift losses and cause negligible drop in air pressure.
An aerodynamically designed axial flow type fan is specifically designed for cooling tower use. A well balanced fan delivers large air volume at high efficiency and low noise level. The fan blades and hub are of cast aluminium alloy (LM-6). The direct driven fan with variable pitched blades . Fans are coupled to slow speed weather proof motor in IP-55 construction. The mechanical equipment is so designed that maintenance of motor and fan blades can easily be carried out without removal of the entire system.