Cooling Tower:
Cooling Tower is used to cool the hot water coming from different units of a process plant and after cooling it is sent back to units. cooling tower is of the following types:
Natural Draft
Force Draft
Balance Draft
Natural Draft cooling tower
It works based on the natural flow of air. dry air from atmosphere is entering into the bottom inlet section of tower and flows up.hot water from different process units is collected and fed at the top of the cooling tower. hot water and dry air comes in contact in counter current manner and evaporative cooling occurs. some water droplets evaporate with upflowing air and latent heat required for evaporation is taken from hot water. so temperature of the cooling water reduce.
packing fill is used inside the cooling tower to get intimate contact and higher residence time between hot water and air.demister pad is used above the packing to minimize entrainment of water droplets.
The shape of a Natural Draft cooling tower is hyperbolic. hyperbolic shape helps to increase the velocity of moist air after coming out from the packed section.
The efficiency of a Natural Draft cooling tower is less in compare to Force Draft and Balance Draft cooling tower. moist air coming out from top of the tower may mix and recirculate with atmospheric air to enter into tower and hence reduce the efficiency of tower.so long structure is needed to reduce back mixing of moist air with atmospheric air.
Cooling Tower is used to cool the hot water coming from different units of a process plant and after cooling it is sent back to units. cooling tower is of the following types:
Natural Draft
Force Draft
Balance Draft
Natural Draft cooling tower
It works based on the natural flow of air. dry air from atmosphere is entering into the bottom inlet section of tower and flows up.hot water from different process units is collected and fed at the top of the cooling tower. hot water and dry air comes in contact in counter current manner and evaporative cooling occurs. some water droplets evaporate with upflowing air and latent heat required for evaporation is taken from hot water. so temperature of the cooling water reduce.
packing fill is used inside the cooling tower to get intimate contact and higher residence time between hot water and air.demister pad is used above the packing to minimize entrainment of water droplets.
The shape of a Natural Draft cooling tower is hyperbolic. hyperbolic shape helps to increase the velocity of moist air after coming out from the packed section.
The efficiency of a Natural Draft cooling tower is less in compare to Force Draft and Balance Draft cooling tower. moist air coming out from top of the tower may mix and recirculate with atmospheric air to enter into tower and hence reduce the efficiency of tower.so long structure is needed to reduce back mixing of moist air with atmospheric air.
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