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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #285709
Title: Development and evaluation of a new aerator for the catfish industry: an update

Author
item Brown, Travis
item Torrans, Eugene

Submitted to: Aquaculture
Publication Type: Abstract Only
Publication Acceptance Date: 11/16/2012
Publication Date: 2/24/2013
Citation: Brown, T.W., Torrans, E.L. 2013. Development and evaluation of a new aerator for the catfish industry: an update. Aquaculture. P. 727.

Interpretive Summary:

Technical Abstract: Modifications to an existing “Power Tube” aerator began in 2010 and the first prototype, known as the “Power Tube Airlift” (PTA), was utilized in a series of oxygen transfer tests in 2011. After thorough evaluation, a second prototype PTA was designed. Two second generation PTAs were fabricated, and installed in a 7.7-ac traditional catfish production pond. Each PTA consisted of a 3.0 ft diameter intake (downcomer) and a 4.0 ft diameter outflow (riser). A twin lobe rotary positive displacement blower was used to supply air to each PTA. Power was supplied to each blower by a 10-hp, 3-phase electric motor that had a rated rotational speed of 1,755 rpm. An 8.00-inch diameter deep-V, dual-groove pulley was attached to the output end of the motor and two V-belts connected the pulley of the electric motor to a second pulley (4.75-inch diameter) that was attached to the input end of the blower. At a rotational speed of 2,950 rpm the blower supplied approximately 130 ft3/min of air (˜12 PSI) to the PTA via a main air supply line. The main air supply line was plumbed into a sparger assembly positioned at a 25 ft water depth on the riser side. Approximately 10-15% of the total air flow was diverted to a diffuser grid place at an 8 ft water depth on the downcomer side. Hybrid catfish, Ictalurus punctatus x I. furcatus, with an average weight of 0.60 lb were stocked at a conservative rate of 2,116/ac and feed daily to satiation. Dissolved oxygen was continuously monitored with an automated system that controlled the operation of the PTAs throughout the study. Total run times were recorded and all repairs and maintenance were accounted for. We expect to harvest large food fish due to the lower than normal stocking density and have an elevated efficiency (lb fish/kW·h). This preliminary evaluation in a commercial-size catfish pond will allow us to begin to define loading limits for the second generation PTAs and to prepare for a higher than normal stocking density in 2013.We also expect additional units to be installed on commercial fish farms for further field tests. The total capital cost to construct the two PTAs including (but not limited to) pond modification (excavation), fabrication and installation of aeration tubes, and blower foundation was $9,857 or $1,280/ac. The total equipment and machinery costs including (but not limited to) complete blower packages, air supply lines, fittings, diffuser grid, and hardware was $12,828 or $1,666/ac. A total capital, equipment, and machinery cost of $22,685 ($11,343 each) was required to build and install these aerators. A partial budget will be developed to look at the profitability of changing from traditional paddle-wheel aerators to PTA type aerators in the same test pond. Some of the material discussed in this abstract comprises the subject matter of a patent application currently pending with the US Patent and Trademark Office.