Location: Warmwater Aquaculture Research UnitTitle: Pumping performance of a slow-rotating paddlewheel for split-pond aquaculture systems Author
Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/19/2012
Publication Date: 1/23/2013
Citation: Brown, T.W., Tucker, C.S. 2013. Pumping performance of a slow-rotating paddlewheel for split-pond aquaculture systems. North American Journal of Aquaculture. 75:153-158. Interpretive Summary: Split-pond systems are the most common intensification variant of the partitioned aquaculture system used commercially and are of great interest to the industry. Split-ponds consist of two sections (fish side and waste treatment side) and water is circulated between the two to remove fish waste and provide dissolved oxygen to the fish. This study evaluated performance of a slow-rotating paddlewheel pump as it related to power input, rotational speed, water velocity, and water flow rate. Measured power input was greater than the calculated power input and water discharge per unit power input decreased as rotational speed increased. The addition of fish barriers increased frictional losses and reduced water flow rate. Results from this study can be used as an aid to design split-pond aquaculture systems.
Technical Abstract: Commercial catfish farmers are intensifying production by retrofitting ponds with variations of the partitioned aquaculture system (PAS). The split-pond system is the most common variation used commercially. The split-pond consists of a small fish-holding basin connected to a waste treatment lagoon by two conduits. Water is circulated between the two basins to remove fish waste and provide oxygenated water to the fish holding basin. Although much research has been devoted to algal and fish production dynamics in variations of the PAS, little information is available on basic engineering considerations for devices to circulate water in these systems. This study evaluated performance characteristics for a slow-rotating paddlewheel pump, including relationships among power input, rotational speed (circular tip velocity), water velocity, and water flow rate. Rotational speeds of 1.0, 2.0, 3.0, and 4.0 rpm were evaluated in open channels and in channels with fish barriers. Measured power input was greater than the calculated power input for all four rotational speeds and ranged from 0.11 to 1.80 horsepower. Water flow rate ranged from 4,548 to 19,330 gal/min and water discharge per unit power input decreased dramatically as rotational speed increased. Installation of fish barriers decreased channel open area and the resulting frictional losses reduced water flow rates. Results from this study provide initial pump performance data for designing split-pond aquaculture systems.