How to increase the abrasion resistance of rotor

[Santhosh KN]

For Kaolin slurry filter presing we are using progressive cavity pumps.After three months of operation we found that the pumping rate is reduced a lot.Upon investigation we found taht this is because of the abrasion. 150 micron Chromium coating done, still after three months ,this again failed.

The rotor is having 125mm diameter and is of 2.8m long. As the medium handled is Clay Slurry with low pH the MOC of the rotor is SS316. This rotor rotates inside a neoprene rubber stator while pumping the slurry. For the pump to develop a pressure of 10 bar the sealing between th rotor and stator is very important and the damage to the sealing area reduces the pump through put.

We are looking for a suitable method for increasing the abrasion resistance of the rotor along the sealing area.

Any suggestions?

Santhosh

 

[BenchTop]

What about pressurised water to lubricate the seal?

 

[FredGarvin]

If abrasion is really what your problem is, then you definitely need a rotor material change. 316 is not a very good choice for this. It sounds like the chromium coating was supposed to give you the wear resistance you needed, but it too failed. I don't see how you can get away with not changing rotor material to something with a higher hardness.

Did anyone inspect your rotors to make sure the chromium coating had the required hardness?

 

[Danger]

Maybe a ceramic coating?

 

[tyroman]

This kind of equipment is used extensively in the oil field and is often referred to as a "mud pump" or "mud motor". It is used to deliver drilling fluid (aka "drilling mud") to the drill bit. Do not know the comparability of your kaolin slurry to the (typically bentonite) clay found in drilling mud - but you might look for a solution within the oil industry experience with this equipment. One thing you probably will not be able to replicate in your application is the oil industry's use of various additives to change the mud's properties.

Have you considered another kind of equipment to accomplish the task... such as an inclined conveyor?