Transport properties of evaporative cooling in a seashell packed bed cooling tower

Abstract

Packing material is the most crucial part in the operation of cooling tower. This project was aimed to investigate the transport properties of evaporative cooling using seashell as packing material in a packed bed tower. A laboratory scale of cooling tower were used to cooled the water discarded from a water distiller, recycle back to the condenser. Cockle shell was used as the packing material, which usually discharged as waste from marine life and fishery industry. The packing section is 15 inch high and filled with seashell which consists of 15 mm to 14 mm of equivalent diameter. The seashell is treated by acid and alkali treatment for surface cleaning and neutralization. The shells were selected according to size range and physical properties of seashell studied which involved of size measurements in terms of equivalent diameter, De, sphericity, , and aspect ratio and density,  of shell. This investigation is focused mainly on cooling tower performance and the effect of circulation rate and cooling water temperature on distill water production rate. The performance of cooling tower using seashell packing is compared to HDPE pipe packing. The results show that seashell packing have higher cooling water range, lower cooling approach and higher cooling tower efficiency than HDPE pipe packing. Meanwhile, cooling water range, R and cooling tower efficiency, e decrease with increasing of water to air ratio, L/G for all circulation rate. The heat transfer coefficient, KaV/L decreases with increasing of L/G ratio with lower circulation rate. The relationship between heat transfer coefficient, KaV/L and water to air ratio, L/G is obtained by linear fitting.