Project Number: 6402-13320-003-03
Project Type: Nonfunded Cooperative Agreement

Start Date: Nov 12, 2003
End Date: Sep 30, 2008

Objective:
The objective of this project is to develop/test a powered u-tube (Power Tube) aerator for use in commercial channel catfish ponds. Target performance parameters would be: 1)One 10-hp Power Tube using a 5-hp motor to move water and a 5-hp blower to inject air) should be capable of supporting 33,000 lbs. of catfish with a pond dissolved oxygen(D.O) concentration of 0 mg/L. 2)The Power Tube must be capable of increasing the D.O. concentration in the worst possible water (0 mg/L) by 4 mg/L. 3)Assuming a catfish respiratory rate of 225 mg 02/lb/hr, water velocity through the 3' diameter inner tube must be approximately 3.3 ft/second to meet the estimated respiratory demand.

Approach:
A motor-powered u-tube aerator ("Power Tube"), scaled to commercial catfish ponds will be constructed and tested. The initial unit will have a 36" diameter tube. A 5-hp three-phase electric motor will power the impeller, which will draw water down and discharge it through a 90 EL. A 5-hp blower, with a capacity to produce up to a 20% air/water mix will inject air into the water before it is drawn down to the bottom of the tube. Measurements will be conducted using a YSI Model 55 dissolved oxygen meter and a General Oceanic Model 2035 MKIV flow meter with a Model 2031H remote digital acquisition readout. The performance parameters to be determined include: water velocity and volume flow in the tube; increase in D.O. concentration at various inlet (environmental) D.O. concentrations; the effect of the air/water mix (determined from 0-20%) on the increase in oxygen saturation. These data will be used to develop the final design recommendations.