For coking preheating, what type of pump should be used for oil transfer – a steam reciprocating pump or a screw pump? What are their advantages and disadvantages? ?
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Our unit is a steam reciprocating pump. During preheating, it leaks severely, stops operating without any apparent reason, and the flow rate is unstable. How can this be resolved? What would be the effect if a screw pump were used? ?
I hope the experts will come and discuss this; waiting for everyone’s replies
The steam reciprocating pump is still the better choice; the amount of oil discharged is inconsistent, which can easily damage the screw pump. Personally, I think as long as the entire system heats up properly and the liquid level in the oil drain tank isn’t high, then it’s fine
Our reciprocating pumps often fail to produce any flow rate. They seem to be operating properly from an external perspective, but no flow is generated; we’re not sure what’s causing this issue, and even the maintenance technicians can’t figure it out
The operating temperature of screw pumps does not meet the required standards; generally, the temperature for screw pumps should not exceed 200 degrees, whereas the oil rejection temperature is above 300 degrees
My device is just a regular centrifugal pump
The coking plant built in 2015 has been using screw pumps for oil drainage, and they have been operating smoothly for over a year now. I used reciprocating pumps before, and I faced all the same problems you mentioned. At first I was hesitant to use screw pumps, but once I did, things became much easier. The screw pump outlet has a return circuit to the tank, equipped with a control valve; by properly regulating the liquid level in the oil rejection tank, it is possible to prevent the tank from becoming empty.
Steam reciprocating pumps are also prone to vacuuming; therefore, the vapor from the oil stripping tank during the preheating stage of the coke tower can be directed into the vent tower to vaporize as much water as possible, which can solve the problem.
There are already many cases of using screw pumps as oil displacement pumps
Increase the pressure in the oil rejection tank in a short period of time without increasing the flow rate, and push it out