A flow straightener has been incorporated into a rotary liquid separator that originally comprised an inlet tube, a shroud plate, an impeller, an inner drum, an outer drum, a housing, a pitot tube, and a hollow shaft motor. As a consequence of the original geometry of the impeller, shroud, inner drum, and hollow shaft, swirl was created in the airflow inside the hollow shaft during operation. The swirl speed was large enough to cause a significant pressure drop. The flow straightener consists of vanes on the back side of the shroud plate. These vanes compartmentalize the inside of the inner drum in such a way as to break up the flow path and thereby stop the air from swirling; as a result, the air enters the hollow shaft with a predominantly axial velocity instead of a swirl. Tests of the rotary liquid separator at an airflow rate of 10 ft3/min (0.0047 m3/s) revealed that the dynamic pressure drop was 8 in. of water (≈2 kPa) in the absence of the flow straightener and was reduced to 1 in. of water (≈0.25 kPa) in the presence of the flow straightener.

This work was done by James R. O'Coin, David G. Converse, and Donald W. Rethke of Hamilton Sundstrand Space Systems International, Inc., for Johnson Space Center. For further information, contact Kristen M. Balukonis, Contract Administrator Hamilton Sundstrand Space System International, Inc. One Hamilton Road Windsor Locks, CT 06096-1010 Telephone No.: (860) 654-6000 MSC-23149

NASA Tech Briefs Magazine

This article first appeared in the April, 2004 issue of NASA Tech Briefs Magazine.

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