Burst evap/water in refrig circuit, need suggestions for clean up

[Arkma]

20 ton r-22 chiller system froze evap. Have water in compressor and refrig circuit. Need suggestions for clean up. Mostly concerned with compressor.

[stuartedm]

remove all water. put on vac for as long as poss then fit high capacity liquid line dryers and change after a day for new one.How did the water get in there?

[Carlo Hansen]

Hi Arkma

For many eyars ago, we used some heat regaining systems and thise system was leaking the refrigerant and we got water in the entire system.
To deal with this, we used 2-3 vacum pumps and used electrical fan heaters to rise the temperature in the tank
and by the colling unit.
Then we changed the filter dryers and mounted filters in the suction line to.
You will have to check the system daily by start up and change the filters 2-3 times.
I dount think you have be warried for the compressor, but
i can tell you, it can take a some time to get the system
working without any problems.
Hope this can help you.

Best regards
Carlo Hansen

[Toosh]

Hi, First of all locate the lowest points of the evap, drain all the water. Then find which tubes are burst some manufacturers allow 10% (in todays world that might not be correct due to cost cutting) to be plugged without losing much capacity. The compressor will have to be stripped and cleaned out which should include replacement parts. Then the system will have to be leak checked using dry nitrogen and a tracer of refrigerant and all leaks repaired. As far as the evacuation of the system i advise that you use a knock out pot before the pump or you will stand there all day changing oil. * the knock out pot is usually a open pot surrounded by an enclosed vessel which the vac pump in and out ports connect to, in the open pot place ice which will knock out the water, by the way it will need a drain on the enclosed vessel to drain the trapped water.

Regards Toosh

ps If you have any other questions feel free to pm me

[slingblade]

The compressor will have to be stripped and cleaned out which should include replacement parts.

such as what? oil?

as long as the system eventually retains a suitable vacum and new oil and driers are fitted then there should be no problem.

[Frosty]

Hi Arkma, this is your worst nightmare come true. How much water has gone in? I've just been sorting out a solvent recovery unit that suffered a burst shell and tube condenser, 300 litres of water entered the system!! Got most out by draining etc. However, remaining moisture difficult to recover due to very low ambients - the vac procedure actually causes the moisture to freeze in low ambients and you just can't get it out!! Had BOC in today, they have a device called a zuggy beast that can distill 2000 kg's of refrigerant per hour - not cheap though - 9k!!!!!!!

[Johnny Rod]

Arkma, Hudson in the US have the same technology we have in the UK, which can remove enormous amounts of water from refrigerant, and depending on the system etc. you can usually do it without shutting down. Frosty's right it isn't cheap but believe me it works. I doubt I can say much more without being labelled as advertising, but as you're in the US anyway check out Hudson:

http://www.hudsontech.com/

Liquid line driers have a very limited capacity and if the mositure level is anywhere near saturation point then they will block anyway.

[Andy]

Johnny,

what about removing water from Ammonia in a plant in N.Ireland

Might know someone who needs this, not much water, but conductive level probes are feeling the effects

Kind Regards. Andy

[Johnny Rod]

I wish I had a quid for every time someone asked me about ammonia...

Simple answer is no I'm afraid, I'm not sure how it is dried on an industrial scale but the driers we use for fluorocarbons are honking great molecular sieves so aren't suitable. Given how cheap ammonia is I think a lot of people simply recharge the system, but it's not an area I know much about. What sort of level is giving these problems?

That said, it seems pretty easy to get old fluorocarbons recovered and disposed of, is this (still) a problem area for ammonia refrigerant?

[US Iceman]

what about removing water from Ammonia?

Andy, the device you are looking for is called an ammonia regenerator. A fancy name for a distillation device.

The ones I am familiar with are essentially a large vessel. Liquid ammonia is allowed to flow into the vessel up to a certain level. The liquid valve is shut off, and a heating device is turned on (usually a steam coil). The hot steam boils off the ammonia. The vapor is allowed to vent back into the refrigeration system through a back-pressure regulator valve.

After all of the liquid ammonia is boiled off, the remaining liquid (water) is drained out of the vessel. Once the water is drained out, more liquid ammonia is allowed to flow into the vessel.

The process continues until the ammonia is dry again.

A very similar process as a refrigerated purger.

[Julian]

Johnny,

what about removing water from Ammonia in a plant in N.Ireland

Might know someone who needs this, not much water, but conductive level probes are feeling the effects

Kind Regards. Andy

Are you sure that the problem with your capacintance rods is not due to oil, these rods as good practice should be removed & cleaned annually, as only a thin film of oil on the rods will give incorrect readings & high level problems

cheers

Julian

[Andy]

Hi Julian
we have not ruled out an oil problem, although the oil pot is just below the connections for the level column

However the fact that when we removed the probe the water and ice came running out the drain valve at the bottom of the level column might not be a good sign

On the oil coating of the probe, I have not heard of that before, but I will look for this the next time a need to calibrate a probe

Kind Regards. Andy

[Andy]

Andy, the device you are looking for is called an ammonia regenerator. A fancy name for a distillation device.

The ones I am familiar with are essentially a large vessel. Liquid ammonia is allowed to flow into the vessel up to a certain level. The liquid valve is shut off, and a heating device is turned on (usually a steam coil). The hot steam boils off the ammonia. The vapor is allowed to vent back into the refrigeration system through a back-pressure regulator valve.

After all of the liquid ammonia is boiled off, the remaining liquid (water) is drained out of the vessel. Once the water is drained out, more liquid ammonia is allowed to flow into the vessel.

The process continues until the ammonia is dry again.

A very similar process as a refrigerated purger.

Thank you Iceman

I was thinking of using a small suction accumulator, with a hot gas boil off coil to boil off the liquid and a rotary feed valve from the chiller shell with a suction solinoide which could be shut, with a pressure regulating valve operating accross the suction solinoide when it is shut.

Hopefully the hot gas will have enough heat

Kind Regards. Andy

[US Iceman]

Hopefully the hot gas will have enough heat

That's the tricky part. It will take a lot of hot gas or electricity to boil off the liquid ammonia. Steam works very well, but only if you have a low-pressure steam source.

[Johnny Rod]

Found out yesterday, as it happens, that York have a gadget I think they call WDO (water dirt and oil) which distils the ammonia. It's not very quick I believe and is something you bolt on to the system and leave there, boils the ammonia gently so not as hot as hot gas would (I guess).

[Josip]

Hello,

this is Phillips Refrigeration product but only for ammonia. Water does not impact ammonia system too much.

In Saudi Arabia-Riyadh when changed old pipes in one pipe pocket (due to valve construction) was more then 70 lit of water. Water was frozen (-40C, 8" very long suction pipe ) and system was running for 25+ years. After pump down of ammonia we leave system 2-3 days to heat a little to evaporate remain ammonia from remain oil, then Niagara came out..

It was also without air purger or anhydrator. Just manual purging from time to time.

Now we install air purger and thinking about installation of anhydrator.

[Josip]

Last page of anhydrator