Question for an expert about Danfoss Maneurop compressor

[rolocz]

Hello all,

About two weeks ago I had serviced a water cooler that uses a Danfoss Maneurop Model MT144 that uses R22 gas and 160p mineral oil.

The water cooler has been sitting unused for 18 months, and there is no way to know when was the last maintenance and how old it is.

As the technician opened a valve to let the gas out (to the free air :eek:) some oil dripped from that valve and I asked if that was normal, the technician shrugged and said that yes.

Now the water cooler seems to be working well and the temperature of the water in the pool is maintained at the correct level. There are no strange sounds and the compressor seems to be working smoothly.

But later, I told to a friend (who works with natural gas powered refrigerators) about the oil that is apparently mixed with the gas and he said that that is the indication of an internal leak and that could be a serious problem.

Well, as may be clear at this point I know next to nothing about those compressors and would like to know if someone out there who knows about this stuff could clear a few doubts:

1)is the oil in the gas normal? Is that the indication of an internal, dangerous leak? why?

2)how often should the compressor be maintained? the answers from the different people I've asked range from 6 months to 1 year.

3)The oil and gas must be changed at the same time always? some said that only the gas must be changed.

4)What else can I easily check to make sure that the compressor is ok?

What else should I know about those machines (which are to me surprisingly complex)? I'm afraid that I could be easily lied to due to my ignorance.

I've read your 101 but I think that that wasn't that helpful.

I'll give any other information that is needed.

Thanks in advance!

[Brian_UK]

Oil is moved around the system with the gas, this is quite normal.

When you open a valve some oil may come out, also normal.

Gas should not need changing from the day of first use unless it is removed for replacement/repair of parts.

Check the system 6 moths/year.


and he said that that is the indication of an internal leak and that could be a serious problem.This is untrue, as previously stated the oil is lightly mixed with the refrigerant and moves around the system.

If the system is working then don't try and fix it. ;)

[josei]

water cooler that uses a Danfoss Maneurop Model MT144 that uses R22 gas and 160p mineral oil.

...I know next to nothing about those compressors and would like to know if someone out there who knows about this stuff could clear a few doubts...

Thanks in advance!

Rolocz pls find a poster and manual for MT series of Maneurop Compressor here>> http://j.mp/Blog-Josei-100406

Saludos desde Colombia,
Josei :cool:

[Brian_UK]

Unfortunately I think that OP is a one post wonder. ;)

[rolocz]

Unfortunately I think that OP is a one post wonder. ;)

Hello
Sorry for having been a "one post wonder"! :D Thanks for your reply, it was good for my peace of mind, but I don't agree in waiting for things to fail before taking preventive action. :cool:

The compressor about which I originally asked in this thread is now dead. Oil was mixed with the water. The new compressor is in the way but the refrigerator technician is frowning upon the fact that the water that circulates in the circuit is full of fine sand. I fear that he may use that to avoid a warraty claim.

The refrigerator helps in regulating the temperature of the water of a pool where concrete test specimens are left for hardening a few days. These specimens leave a fine sand that the pump pumps through the whole system, (pipes, pump, electrovalves, heater and cooler).

There is a filter system in place but it gets saturated in about 3 days so the local maintenance technician simply removed the cartridges due to the high cost and scarce availability of the replacements. It was more important to keep the water at the right temperature. That way and with no maintenance the refrigerator worked for about 18 months after a maintenance that followed an unknown period of time being out of service.

The refrigerator technician says that the system should only pour cool water into the pool and drain the extra water so that the "dirty" water never recirculates into the refrigerator.

That would be very wasteful because in that city the temperature is usually above 30 celcius (86F) and the refrigerator works almost continuously except for a few weeks during winter.

My questions is: Is there something that I can install that help remove the thermal energy off the pool water while keeping the water of the refrigerator circuit separated from the water in the pool?

As far as I could search it looks like the only solution is a large capacity and self cleaning filter, but that is too costly, well above the budget.

I promise that this time I will tell you about the final setup. ;)

Regards

[chillerman2006]

Hello

My questions is: Is there something that I can install that help remove the thermal energy off the pool water while keeping the water of the refrigerator circuit separated from the water in the pool?

As far as I could search it looks like the only solution is a large capacity and self cleaning filter, but that is too costly, well above the budget.

I promise that this time I will tell you about the final setup. ;)

Regards

Hi Rolocz

the way to comabat your issue is to run two seperate water circuits through heat exchangers

your pool water runs through one part & the chiller water runs through the other

this way you can keep filters in the chiller circuit and leave them out of pool circuit

sand is very abrasive so I would suggest two pumping circuits for the pool

so one can be isolated and serviced while the other is in use

R's chillerman

[monkey spanners]

Have seen dairy milk filters used in similar aplications,

http://www.milkingmachines.co.uk/uk2shop-22.htm

They can be taken apart for regular cleaning.

If the compressor oil has got into the water circuit the heat exchanger must be broken, if its not fixed the new compressor will fail also.

[rolocz]

Hi Rolocz

the way to comabat your issue is to run two seperate water circuits through heat exchangers

your pool water runs through one part & the chiller water runs through the other

this way you can keep filters in the chiller circuit and leave them out of pool circuit

sand is very abrasive so I would suggest two pumping circuits for the pool

so one can be isolated and serviced while the other is in use

R's chillerman


Thanks for the answer, indeed, a heat exchanger seems to be the best alternative.

When asked, another refrigerator technician suggested installing a heat exchanger using glycol for the refrigerator circuit.

Seems a nice solution as it would be a simple add on and there is no need to modify electrical, electronical circuits or other parts of the system.

Thanks for the suggestion

[chillerman2006]

Have seen dairy milk filters used in similar aplications,

http://www.milkingmachines.co.uk/uk2shop-22.htm

They can be taken apart for regular cleaning.

If the compressor oil has got into the water circuit the heat exchanger must be broken, if its not fixed the new compressor will fail also.

Hi Jon

just had a look at them myself

would suit his purpose nicely

he could run triple bypass circuits so he can always have one clean, one in use & one being changed

would certainly be a cheaper option than heat exchangers in the short term but I wonder how this would balance out long term, bearing in mind the abrassiveness of sand and its effect on a heat exchanger

R's chillerman

[simon@parker]

hi CM have given this some brain time could he not fit a stainless steel heat ex to cut out the alkalie corrosion and if he fitted a settlement tank ( take pipe to a low level have section approx 3x size of running bore ) to take out or settle out small particles ie sand if it was made to be easily removed could be binned everytime it changed also as its concrete it would harden in tank at lowest point as it heavier just a thought what do you think ?

[chillerman2006]

Evening Simon

Sounds good to me mate, any reduction in the % of sand in the mix would reduce wear/tear on the hx's

I have seen once, a system similar to your suggestion, it was a chiller for a swimming pool in Dubia, where they were using the pool to reabilitate race horses after injury and the horses dont get out the pool to do there business

R's chillerman

[monkey spanners]

Make ice blocks, chuck in tank as required :D

[simon@parker]

Make ice blocks, chuck in tank as required :D
dam i knew i was missing somat :)

[simon@parker]

Evening Simon

Sounds good to me mate, any reduction in the % of sand in the mix would reduce wear/tear on the hx's

I have seen once, a system similar to your suggestion, it was a chiller for a swimming pool in Dubia, where they were using the pool to reabilitate race horses after injury and the horses dont get out the pool to do there business

R's chillerman
the longer u made the settlement vessle the more you would remove also the lower u made it to rest of system just an idea think it would work a treat so how do i get some fractions on my board is it like super tech points an ya gotta be kudosed up to get em ? lol :)

[rolocz]

Hi Jon

just had a look at them myself

would suit his purpose nicely

he could run triple bypass circuits so he can always have one clean, one in use & one being changed

would certainly be a cheaper option than heat exchangers in the short term but I wonder how this would balance out long term, bearing in mind the abrassiveness of sand and its effect on a heat exchanger

R's chillerman



We are leaving filtering out for now. We are adding a cleaning circuit that will have to be run maybe once a week. The valves set a circuit that pump clean water from a reservoir to drainage so the operator must push a few buttons and leave water running until it is visibly clear.

Also, we found that the whole refrigerator system was purchased 10 years ago, but there is no way to know how long it's been working and there is no maintenance record.

The water feels very smooth but leaves hands very dry. I was told that it isn't exactly "a very fine sand", rather puzzolane. Probably it can be rough on the surfaces when pushed by the pump. It also seems to stick and accumulate on the surfaces that are in contact with the water.

Thanks for the assistance

[rolocz]

Have seen dairy milk filters used in similar aplications,

If the compressor oil has got into the water circuit the heat exchanger must be broken, if its not fixed the new compressor will fail also.

Indeed, the heat exchanger failed and is being replaced.

Thanks

[chillerman2006]

the longer u made the settlement vessle the more you would remove also the lower u made it to rest of system just an idea think it would work a treat so how do i get some fractions on my board is it like super tech points an ya gotta be kudosed up to get em ? lol :)
The system I worked on in Dubia was using a rather huge buffer tank, water in at the middle, water out at the top, with a large gauze typr filter above the inlet to catch the straw, this allowed the horses stuff in the mix to fall to the bottom, where there was a 8inch drain valve..........as for the tech points :confused:

[simon@parker]

We are leaving filtering out for now. We are adding a cleaning circuit that will have to be run maybe once a week. The valves set a circuit that pump clean water from a reservoir to drainage so the operator must push a few buttons and leave water running until it is visibly clear.

Also, we found that the whole refrigerator system was purchased 10 years ago, but there is no way to know how long it's been working and there is no maintenance record.

The water feels very smooth but leaves hands very dry. I was told that it isn't exactly "a very fine sand", rather puzzolane. Probably it can be rough on the surfaces when pushed by the pump. It also seems to stick and accumulate on the surfaces that are in contact with the water.

Thanks for the assistance
the concrete will have a high level of lime in it making it very alkalie am guessing you will have a dusty atmosphere as well so water will have a high corosion rate as well will make it feel strange so would suggest you change water as much as you can to reduce the damage to chiller system if it has been in 10 yrs go fo a complete new system with a new design will be worth the outlay in long run :)

[AUScooler:-)]

Another option is to build a small tank, make a metal frame, line it with ply wood and then coat it with an epoxy resin fibreglass and seal it. Make a customised stainless steel cooling coil ( no fins required ) and lower it into the tank.