Submersible pump selection
Thread Content
Our company is an ammonia synthesis plant; the temperature of the secondary water is around 45 degrees. The original model of the secondary water pump is 300QJ 300-44, with a flow rate of 300 cubic meters, a head of 44 meters, and a motor power of 63 kW. I would like to purchase a new secondary pump with a flow rate of 300 cubic meters, a head of 35 meters, and compatibility with temperatures up to 40 degrees Celsius. Would it be feasible to use one of these instead? Considering that the head has decreased compared to before, and although the medium temperature is high, the motor does less work – is this reasonable?
The pump model used by the poster is problematic; the flow rate of 300QJ does not reach 300 cubic meters – it should be 350QJ. For pumps that comply with national standards, the flow rate should be 320 cubic meters, with a head of 44 meters at stage 4. At such high temperatures, the QJR type should be used instead of the QJ type. Also, would it be possible to use a new secondary pump with a flow rate of 300 cubic meters, a head of 35 meters, and a suitable operating temperature below 40 degrees Celsius instead? Given that the head is lower than before, it makes no sense to try to use the motor even though the temperature of the medium is high; a medium temperature of 45 degrees already means that the QJ type cannot be used (the maximum operating temperature for QJ is only 20 degrees Celsius – don’t be deceived by the manufacturers!) Even if a flow guide is added outside the motor, it cannot be used at 45 degrees for the medium.)