Rising to the challenge
If these media are also boiling-sensitive or contain gas, it is often necessary to empty the tank completely, for example in the case of waste water containing hazardous liquids, such as those often found in refinery waste tanks. Hydrocarbons often occur here together with boiling-sensitive media, under atmospheric conditions and at high temperatures.
If solids additionally occur in the medium, this generally exceeds the capabilities of standard submerged column pumps.
A distinction needs to be made between submerged column pumps and submerged motor pumps.
With the former, the pump hydraulics are submerged in the pumping liquid. With submerged motor pumps, not only is the hydraulic components, but also the motor are submerged in the pumped medium.
Standard pumps with these designs, equipped with product-lubricated slide bearings and a double mechanical seal, are often unsuitable for dangerous and challenging applications.
Their seals and bearings are not safe to run dry, because the slide bearings, seals and...