Performance Evaluation of Different Aeration Systems for Aquaculture

Abstract

Abstract. Aeration system plays a vital role to increase the production rate of semi intensive and intensive aquaculture system. Various types of aeration systems have been developed over the years to maintain the desired level of dissolved oxygen concentration in the pond water. Proper performance evaluation and comparison of aeration systems are essential before selecting them. In this study four different types of aerators; paddle wheel aerator, propeller-aspirator-pump aerator, circular stepped cascade aerator and pooled circular stepped cascade aerator were selected to evaluate their efficiency in terms of standard oxygen transfer rate and standard aeration efficiency. Aeration tests were conducted in a brick masonry tank at Indian Institute of Technology Kharagpur, India. The maximum standard aeration efficiency of 1.65 kg O2/kWh was estimated for a single hub paddle wheel aerator. In case of propeller-aspirator-pump aerator, the maximum standard aeration efficiency of 0.42 kg O2/kWh was obtained at a positional angle of 75 degree, rotational speed of 2840 rpm and submergence depth of 0.14 m of propeller shaft. Standard aeration efficiencies based on estimated brake power of the prototype circular stepped cascade and pooled circular stepped cascade aerators ranged between 2.16 to 2.70 kg O2/kWh and 2.43 to 3.23 kg O2/kWh respectively. It has been found that the pooled circular stepped cascade aerator has more standard aeration efficiency compared to the other aerators tested.