Centrifugal shielded pump: issue with oversized selection?
Thread Content
Our factory has an infusion pump capable of operating at a temperature of -30 degrees Celsius. The actual height of the building is 20 meters, and the pipeline resistance is unknown. The technicians selected a model with a head capacity of 48 meters and a flow rate of 10. The pump cannot be started during debugging; a pressure difference error occurs, with the pressure difference set at 1 kg. Therefore, the pump’s outlet valve was closed to create a manual resistance of 48 meters of head. Drive it for only about one round to see the current adjusted to the rated value. It is assumed that the traffic volume also meets the standard. With such abnormal use, is the current also proportional to the power flow? The liquid being transported is at -30 degrees, so it should cool down well. The problem is that among the several pumps in the same container, some are very cold with their housings frozen, while the housings of other pumps are around +70 degrees and feel hot to the touch. Why is it like this
1. The head of a pump is generally calibrated using water; I’m not aware of the density of your low-temperature liquid, so the head value can be converted accordingly. 2. The flow rate and current of a centrifugal pump are not directly proportional to each other; the pump has its own flow rate characteristic curve, which you can find information about online. 3. High temperatures may be caused by poor circulating cooling of the pump; make sure to thoroughly check the circulating cooling system of pumps with high temperatures to prevent the bearings from being damaged.
High temperatures should result in more intake and less output, as the medium undergoes repeated work!
Repetitive work does indeed cause a rise in temperature, but I adjust the opening degree of the pump outlet valve according to the rated current, that is, the pump outlet valve is gradually opened until the rated current is reached. Could you please indicate that the traffic volume has also reached the specified limit?
It’s not the case that everything will be fine just by following normal procedures! What if it’s a selection issue? Since not that much head is required, the impeller can be modified by cutting it (keeping the front and rear covers while only machining the flow channel blades!) If the turning tool cannot reach such a deep depth, remove part of the back cover)! It is also possible to add an additional ring inside the inlet ring of the impeller in order to reduce the amount of fluid entering! If you have any issues with WeChat 18615002545, feel free to reach out at any time!