AIR ENTRAINMENT IN A PARTIALLY FILLED HORIZONTAL PUMP SUCTION LINE

摘要

Several investigations have been conducted concerning vortexing and air entrainment in horizontal suction lines from pump sumps [1 through 11]. All of these investigations are for conditions where the water level remains above the top of the horizontal suction line. Recent changes to the D. C. Cook nuclear plant emergency operating procedures has resulted in the need to allow the water level in the Refueling Water Storage Tank (RWST) to drop below the top of the horizontal pump suction line for short periods of time. Since the available data were not applicable to this situation, hydraulic testing was conducted using a 1:4 geometric scale model of the RWST and associated pump suction piping. Several water levels and flow rates were tested with the water level both above and below the top of the suction pipe. The test results show that for Froude numbers less than about 0.33, the water level can be lowered below the top of the pipe without significant air entrainment.