Aspects of enhancement and retardation of evaporation rate of soak liquor in tannery solar pans

The present study is meant to enhance the amount of evaporation of soaking/ pickle liquor by using a non-conventional (solar) energy source. An increas e in surface area of evaporation is achieved by floating glass tubes covere d with black cloth. Experiments on the rate of evaporation of water from sa lt solution were performed with and without the floating glass tubes under identical conditions. The results indicated about 26% enhancement in the ev aporation rate in the presence of floating glass tubes. It has been establi shed that the degree of enhancement varies depending on the number of float ing glass tubes, concentration of the solution and the wind velocity. The i ncrease in the rate of evaporation is due to the additional surface area ma de available and also the higher energy absorbed from the sun by the black surface. Experimental results on the effect of increasing the depth of the fluid surface from the top of the solar pan on the evaporation rate are als o furnished. They show a continuous decrease in the evaporation rate with i ncrease in the depth of the fluid. This paper presents the experimental dat a and discusses the design aspects of solar evaporation pans.