Gearing is typically 14, slipnominal is typically 50 rpm and Hznominal is either 50 or
60 Hz. SAE was based upon electric power consumption, rather than mechanical
energy delivered to the paddles. This more fairly represents the cost of operation,
but yields figures that are numerically lower than those normally advertised.
The test basin was 8.85 m long and 4.173 m at the greatest width, oval shaped
as illustrated in Fig. 2. Spatial replicate tests were carried out with the aerators
always situated as shown. Our oxygen transfer measurements were generally in
accordance with the ASCE/ANSI 2-91 standard (1993), except only one DO probe
was used. Data were acquired at 10 s intervals, providing a high-resolution
representation of DO levels as water circulated around the testing basin. Fig. 3
illustrates the density of data, where bumps are the tracks of individual parcels of
water passing by the probe. The circulation period of the test basin was on the
order of 1 min when paddling at full speed.