Pump head
Thread Content
A set of pumps, one in operation and one as backup, with a transfer distance of 1500 meters; the density of the liquid is around 1.2. The required head is 38 meters for liquid injection, which is equivalent to 45 meters of water column pressure. News came from the pump factory: the maximum head is 40 meters of water column, otherwise it will overheat. The theoretical power consumption is 39 KW, so a 45 KW motor is selected. Is it possible?
Can you tell if it’s overheating without checking the traffic?
All pumps have a thermostatically controlled minimum flow rate; this is because when the flow rate is low, the heat generated by disk friction cannot be dissipated, resulting in heating. What’s the point of talking about head alone, without considering flow rate?
This is not heat accumulation due to the minimum flow rate; the flow rate in this project is around 200 cubic meters, and the issue mainly lies in the design of the pump. My question is: I have chosen a head of 38 meters, which requires 39 KW of power. The manufacturer is offering a motor with 45 KW of power – will this be sufficient to achieve a head of 40 meters?
Whether the head can reach 40 meters is determined by the rotational speed, impeller diameter, and flow rate. The motor is not overloaded, and it does not get hot. To check whether the pump is hot or not, look at the flow rate
Since it’s a buyer’s market these days when making purchases, it’s enough to make a few adjustments to the supply contract; after all, the supplier will guarantee everything, right?
One could consider increasing the pipe diameter slightly to reduce the head pressure.
When specifying requirements to the manufacturer, one usually only mentions the head pressure and the density of the liquid in question; there is no need to convert it into terms of water columns. So if you tell them to calculate the head pressure and density, they will carry out the conversion on their own. If you mention two parameters at once, it’s likely the manufacturer will be confused :)
For Chinese people, contracts are sometimes used as a reference only; some suppliers don’t even read the contract terms or technical agreements. If you give it to them, they’ll sign it, and then they’ll try to avoid responsibility if something goes wrong. A demand of 39Kw with a 45Kw motor may not be sufficient to handle it. The efficiency of the pump is not 1