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AIM :

To determine the overall heat transfer coefficient in a forced draft counter current cooling tower. To measure Tower Characteristic parameter KV/L for various liquid and air flow rates (L/G) in a counter-current Forced draft Cooling Tower.

INTRODUCTION :

Water from condensers and heat exchangers is usually cooled by an air stream in spray ponds or in Cooling Towers using natural draft or forced flow of the air. Mechanical draft towers are of the forced draft type, where the air is blown into the tower by a fan at the bottom. The forced draft materially reduces the effectiveness of the cooling.

THEORY :

Water may be cooled by the air as long as its temperature is above the wet bulb temperature of the entering air. Markel’s theory is used which is based on enthalpy potential difference as the driving force.

 

 

For heat transfer operation: Each particle of water is assumed to be surrounded by a film of air and the enthalpy difference between the film and the surrounding air provides the driving force for the cooling process. Assume that liquid is warmer than gas.

For mass transfer operation: Each particle of water is assumed to be surrounded by a film of air and the enthalpy difference between the film and the surrounding air provides the driving force for the cooling process.