Effects of J-groove casing treatment on internal flow states of shaft-less centrifugal pump

摘要

The shaft-less centrifugal pump was developed based on the magnetic inductive system. The main feature is no shaft and floating impeller rotates in an independent condition because of bearing less and seal less structure. However, in low flow condition, the floating impeller rotate in instable condition. And, it was because of pressure fluctuation in internal flow. On the other hand, J-grooves is developed by KROKAWA for the purpose of improvement in unstable phenomena of mixes tuebo machine. It was reported that J-grooves was affect the internal pressure field. In this paper, we tried to control impeller attitude by use of J-grooves. Furthermore, the pump performance and floating condition of impeller were measured in order to make clear the effects of J-groove casing treatment on the shaft-less centrifugal pump.