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Vacuum Pump

Vacuum Pump

Vacuum Pump

We currently use a Stokes 412H pump which is used for pulling solvent laden vapors out of a process vessel.  The solvents contamintae the oil in the pump and destroy the pump.  I assume people have used pumps succesfully for thi soperation and wonder what type and brand of pumps were used?

THe solvents can be xylene, toluene, water, heptane...

RE: Vacuum Pump

We are using Kinney vacuum pump. We have the same problems. Right now we install a decant line from the oil tank and drain the solvent frequently. It works well so far. I am not sure whether this will work for long term.

RE: Vacuum Pump

liquid ring pumps are commonly used in such services (depending on the vapor pressure of components that you are working with).

in any event you need to use coalescer filters and possible a cooler upstream of you pump to catch and condense the vapors.

liquid jet pumps also work well and the circulating fluid is stripped before returning to the pump nozzle.

RE: Vacuum Pump

Dear Dideyjohn,

Solvent recovery is an ideal application for a dry (oil free) pump combined with a condenser on discharge.
Using an oil lubricated pump, check your starting and shut-down procedure: 15mn preheating will help to avoid solvent condensation in the pump also an N2-purge before shut-down.

Hope it helps,


RE: Vacuum Pump


Replace your Stokes 412H Pump with an eductor that can draw a high vacuum (28" Hg).  Ensure that the pump you use to provide the motive fluid to the eductor can pump a liquid saturated with a gas.  Discflow pumps are ideal for this situation.

NOTE:  The eductor must beable to handle various flow rates and pressures.  Very few eductors on the market can accomplish that task.  

RE: Vacuum Pump

I can't seem to loacte discflow pumps in the USA - who manufacturers them?

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