George Askew
06-03-2008, 04:56 PM
Hi Guys I am new to the forum so Hi to you all
Also new at this type of Forum thing. If I cant send / attach pix can anyone responding please send me their E addresses and I`ll send them.
I am running a refrigerated depot in the Congo as a favour for a friend and in semi retirement as it’s a great place to live – if you like the simple clean unpolluted life (and great diving and fishing!)
I last worked on fridge systems 42 years ago and there have been some changes and my memory lets me down sometimes. So I recently spent 10 days at a friends workshop in S Africa getting in touch again and he passed me as OK and able to do most things – but if I was stuck to just write or phone him for advice or write.
Well this is not working out too well as phoning is bad and complicated from here so E mail and Skype are better – but currently skype is not working here, and he seems too busy to respond to me. As I have so much catching up to do I am sure you are going to see a lot of me. All any help will be greatly appreciated by this Old Fart.
Trouble is one can get nothing sophisticated here [Like refrig or welding gasses, Nitrogen - anything], and normally that has to be imported via S Africa and that can take from weeks [air-freight] to months via land transport (Just look at a map!). And bottles of gas cant go by air.
We also have very little in the way of tools and spare as this is Grass-roots fishing business and prior to me no-one who knew anything about fridges.My friend [who owns the Co] was told that all the used gear he got was in good condition. [But thats not the case!And I have some problems with a used Blast Freezer mounted on a 20ft container that I would appreciate some comments on.
The blast freezer was cut between the condensing and evaporating side with the former put inside the container for the massive journey from way past Cape Town to Kalemie on Lake Tanganyika. Vibrations caused some pipes to fracture on the evap coil.
So, a couple of things please;
1. After we had brazed the blast freezer evaporator and conds unit together again we found 3 fractured bends on the “spider” /”distributor’ which couldn’t be easily seen and impossible to work on where it was and with our primitive brazing gear [O2 and home made Acetylene from Carbide rocks being put into an old fire extinguisher] - so had to drop the coil.
2. We fixed the ‘spider’ with a Propane burner and huge petrol blow-torch – but they just don’t deliver the heat.
3. it is evident that the system has suffered a compressor burnout in the past judging from the crap [Black oil with bits of charred windings shellac in the oil that I found in the bottom of the suction line on the evap], and in the expansion valve. [See pix]
4. So it looks like I may have a major overhaul in our quiet season [July] when I`ll have to strip everything and clean it out. And if so maybe I`ll have all the stuff I need by then.
5. What really puzzles me is how this gunk got past the drier???
6. For want of anything better here I managed to buy some rubbing alcohol from the hospital and my plan was to put the evap on its end and pour alcohol into the evap through the exp v/v block. The plan was to pass it right thru the coils [shaking it as we did so] and dump it out of the suction line. But we were not too successful in getting more than a few litres in. It just wouldn’t run in and kept overflowing – could I have had airlocks or something else that would prevent the fluid from going in fully?
7. I have used our fart-arse [100psi] little tyre compressor to blow air thru the coil to get the alco out. I had one big gush of fluid come out and then just ‘spitting’. There is not enough air pressure and volume to really give it a good hard blow. I think from the volume I collected that most of it is out now. But how do I be sure? Otherwise I`m stuck with flushing the evap and getting the alco out as it has not evaporated out and there must be traces of it left.
8. Without wasting a whole 13kg bottle of R408 what are my other options for flushing it out – and for how long must I flush?
9. If I hook up the little compressor and leave it running for a few hours is the air movement going to help it evaporate?
10. What I was pleased to see was that the mixture of alco and oil that was blown out of the evap was yellow not black. And this has really confused me.
11. If the evap suction ‘sump’ [before it rises back up to go the compressor], had contaminated oil but the rest of the evap is clean – How did it get there? Could it have somehow have been sucked back from the compressor – but stayed in the ‘sump’ and not been able to penetrate the coil? It is the only explanation that I can come up with.
12. The oil that comes out in a foam from the compressors suction & discharge valves nipples is the usual frothy yellow - so it looks like the compressor is clean and might be OK.
13. So my dilemma is this : I have conflicting evidence. Some parts of the system look/are clean and yet I found the dirt in the evap sump and in the expansion v/v. What is going on?
14. How can I be absolutely sure that the system is OK and does not need a major flushing?
15. The coil has 2 sensors/ thermometers ?? that are dangling on the expansion valve side. They are hollowed out as tho they sit on a ˝ inch pipe but the pipes there are mainly half round chiller ends and I can’t figure out where they should go exactly and how they would be held in place. With cable ties – or?? [See photo showing where I put them].
16. Can they be placed anywhere – or is position critical?
Comments please.
George
Also new at this type of Forum thing. If I cant send / attach pix can anyone responding please send me their E addresses and I`ll send them.
I am running a refrigerated depot in the Congo as a favour for a friend and in semi retirement as it’s a great place to live – if you like the simple clean unpolluted life (and great diving and fishing!)
I last worked on fridge systems 42 years ago and there have been some changes and my memory lets me down sometimes. So I recently spent 10 days at a friends workshop in S Africa getting in touch again and he passed me as OK and able to do most things – but if I was stuck to just write or phone him for advice or write.
Well this is not working out too well as phoning is bad and complicated from here so E mail and Skype are better – but currently skype is not working here, and he seems too busy to respond to me. As I have so much catching up to do I am sure you are going to see a lot of me. All any help will be greatly appreciated by this Old Fart.
Trouble is one can get nothing sophisticated here [Like refrig or welding gasses, Nitrogen - anything], and normally that has to be imported via S Africa and that can take from weeks [air-freight] to months via land transport (Just look at a map!). And bottles of gas cant go by air.
We also have very little in the way of tools and spare as this is Grass-roots fishing business and prior to me no-one who knew anything about fridges.My friend [who owns the Co] was told that all the used gear he got was in good condition. [But thats not the case!And I have some problems with a used Blast Freezer mounted on a 20ft container that I would appreciate some comments on.
The blast freezer was cut between the condensing and evaporating side with the former put inside the container for the massive journey from way past Cape Town to Kalemie on Lake Tanganyika. Vibrations caused some pipes to fracture on the evap coil.
So, a couple of things please;
1. After we had brazed the blast freezer evaporator and conds unit together again we found 3 fractured bends on the “spider” /”distributor’ which couldn’t be easily seen and impossible to work on where it was and with our primitive brazing gear [O2 and home made Acetylene from Carbide rocks being put into an old fire extinguisher] - so had to drop the coil.
2. We fixed the ‘spider’ with a Propane burner and huge petrol blow-torch – but they just don’t deliver the heat.
3. it is evident that the system has suffered a compressor burnout in the past judging from the crap [Black oil with bits of charred windings shellac in the oil that I found in the bottom of the suction line on the evap], and in the expansion valve. [See pix]
4. So it looks like I may have a major overhaul in our quiet season [July] when I`ll have to strip everything and clean it out. And if so maybe I`ll have all the stuff I need by then.
5. What really puzzles me is how this gunk got past the drier???
6. For want of anything better here I managed to buy some rubbing alcohol from the hospital and my plan was to put the evap on its end and pour alcohol into the evap through the exp v/v block. The plan was to pass it right thru the coils [shaking it as we did so] and dump it out of the suction line. But we were not too successful in getting more than a few litres in. It just wouldn’t run in and kept overflowing – could I have had airlocks or something else that would prevent the fluid from going in fully?
7. I have used our fart-arse [100psi] little tyre compressor to blow air thru the coil to get the alco out. I had one big gush of fluid come out and then just ‘spitting’. There is not enough air pressure and volume to really give it a good hard blow. I think from the volume I collected that most of it is out now. But how do I be sure? Otherwise I`m stuck with flushing the evap and getting the alco out as it has not evaporated out and there must be traces of it left.
8. Without wasting a whole 13kg bottle of R408 what are my other options for flushing it out – and for how long must I flush?
9. If I hook up the little compressor and leave it running for a few hours is the air movement going to help it evaporate?
10. What I was pleased to see was that the mixture of alco and oil that was blown out of the evap was yellow not black. And this has really confused me.
11. If the evap suction ‘sump’ [before it rises back up to go the compressor], had contaminated oil but the rest of the evap is clean – How did it get there? Could it have somehow have been sucked back from the compressor – but stayed in the ‘sump’ and not been able to penetrate the coil? It is the only explanation that I can come up with.
12. The oil that comes out in a foam from the compressors suction & discharge valves nipples is the usual frothy yellow - so it looks like the compressor is clean and might be OK.
13. So my dilemma is this : I have conflicting evidence. Some parts of the system look/are clean and yet I found the dirt in the evap sump and in the expansion v/v. What is going on?
14. How can I be absolutely sure that the system is OK and does not need a major flushing?
15. The coil has 2 sensors/ thermometers ?? that are dangling on the expansion valve side. They are hollowed out as tho they sit on a ˝ inch pipe but the pipes there are mainly half round chiller ends and I can’t figure out where they should go exactly and how they would be held in place. With cable ties – or?? [See photo showing where I put them].
16. Can they be placed anywhere – or is position critical?
Comments please.
George