河北某钢厂使用的炼钢转炉炉口冷却热水循环泵,流量410m3/h,扬程47m,轴功率65. 6kW,配套电机功率75kW， 钢额定电流值为139.7A在设备调试中发现电机电流达到了145A， 超过了电机额定电流。
The hot water circulating pump used in a steelmaking converter in Hebei Province has a flow of 410m3 / h, a lift of 47m, a shaft power of 65.6kw, a matched motor power of 75kW, and a steel rated current of 139.7a. It is found that the motor current has reached 145a, exceeding the rated current of the motor.
Solution process: it is observed that the current of the motor is indeed 145a on site, and the pump head is only 38m according to the calculation of the pump inlet and outlet pressure. The analysis shows that the pump head is too high, the pump rotates under the super flow, resulting in the increase of the pump power, and the motor power reserve system of the pump is small, resulting in the motor super current under the large flow of the pump. Therefore, it is decided to close the outlet valve of the small pump to the current rating. It is suggested that when the pump is overhauled, the outside of the impeller of the pump can be cut properly to reduce the outside of the impeller so as to save energy. Slurry pump manufacturer