Article

Design and peroormance of paddle wheel aerators

Department of Fisheries and Allied Aquacultures, Alabama Agricultural Experiment Station, Auburn University, Alabama 36849, USA
Aquacultural Engineering (Impact Factor: 1.23). 01/1988; 7(1):39-62. DOI: 10.1016/0144-8609(88)90037-4

ABSTRACT An apparatus was constructed for testing the influence of paddle shape and depth and paddle wheel speed and diameter on oxygen-transfer characteristics of paddle wheel aerators. Paddles triangular in crosssection were more efficient than other paddle shapes. Standard oxygen transfer rate (SOTR) increased with increasing paddle depth and paddle wheel speed while standard aeration efficiency (SAE) declined. For a particular depth and speed, SOTR increased with increasing paddle wheel diameter. The greatest SAE (2·96 kg O2 kWh−1) was achieved with a 91 cm diameter paddle wheel with triangular paddles operated at 77 rev min−1 and 12·5 cm paddle depth. Three companies made floating, 7·5 kW electric paddle wheel aerators according to design specifications developed in this research. These commercial aerators had high values for SOTR (18·8–21·8 kg O2 h−1) and SAE (2·7–2·9 kg O2 kWh−1) and were much more efficient than other aerators used in channel catfish farming.

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    • "A wide variation in performance of aerators in terms of standard aeration efficiency was found, like, Taiwanese aerator (1.17 kg 0 2 /kWh), Japanese aerator (1.03 kg 0 2 /kWh) and Auburn university design (2.25 kg 0 2 /kWh) (Busch et al. 1974; Boyd and Watten 1989; Boyd, 1998; Colt, 2000a; 2000b). Ahmad and Boyd (1988) provided optimum designs of paddle wheels and Moulick et al. (2002) used similarity criteria in predicting the oxygen transfer performance of paddle wheel aerators. The centrifugal surface aerator along with the paddle wheel surface aerator had been traditionally used in wastewater treatment (Stukenberg et al., 1977; ASCE, 1997). "
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