You have an air dryer unit installed before the pump?

There is a dryer system for the entire building. I've looked at some point of use dessicant units (need to research cfm requirements) - but I don't want to invest in one if it will only provide a minor improvement. Do you think it would help with the ice?

Is this new plant? If not, was the problem there last time the ambient temp. was about the same?

If no problem last time, then something needs fixing.

I am new to the company - about six months, so I started in at the end of the cold season ... a few cold days in May and June seem to support the correlation between low ambient temp. and difficulty with pumping. John, you and RVZ717 seem to be tracking along the same idea of wet air.

Cheers

You may be exceeding the capacity of the drier to remove water from the air supply. As water accumulates in the air compressor's storage tank, new air heated adiabatically by the compressor will take it up. This water vapor will re-condense as the temperature in the supply line drops due to the lower ambient in cold weather. The air storage tank may just need to be drained oftener. Air supply piping should also be sloped so that it will drain any water that condenses in the supply line back to the storage tank, not to the machinery.

If this has already been done, you might consider installing a supplementary drier at the location of any machine that is experiencing a problem. Something as simple as a water trap might do. Good luck.

Sir:

Expanding exhaust air from the diaphragm pump cools below the freezing point of water....... hence the ice formation. Same as refrigeration principle

If it were my job to solve, I would use a ..high velocity/small diameter cyclone to remove the moisture ahead of the exhaust....this, with proper experimentation may be able to eliminate the "muffler" if exhausted vertically above the roof line for acoustic control.

It may need multiple cyclones manifolded to accommodate the air flow volume.

Or..an infra red bulb aimed at the existing muffler.

MR. GUY

Does your filter press have two pumps? One a high volume per stroke low pressure and one a low volume per stroke high pressure. The first one fills the filter press and the other one adds pressure to force the water out of the sludge. If so, which one is freezing up? Is the de-watering time too long? Or does the pump stall before it completes the cycle because it is frozen? It doesn't take much water in the air to cause problems with an air operated pump. There may be a few other things you can do to shorten the cycle time and improve filter cake quality, but I need to know the operation of this press to help.

Have you talked to the Head of the Maintance Department? He will know.

I would check the incomming air first for the amount of moisture.

I have seen high pressure pumps freeze up after running at high speed in 90 degree heat.

You may have to run smaller batches to give the system time to recover (THAW)when it is cold.

The ice is probably restricting the air flow exiting the pump and increasing the back pressure which reduces the pumps efficiency. Taking the water out before the pump will be doable but more difficult than after when it condenses naturally. Look at a cyclone after the pump and before the exhaust.

All,

Thanks much for all of the advice. I'll take some steps and post the results soon.

if your air dryer package is working properly, one solution is to change the cycle time of the dryers. my guess is that your dewpoint of the dried air is not low enough. by changing how often the dryer must purge, this will lower your dewpoint. this will not cost you anything except a little more power since more compressed air is vented.