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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

nike123
06-03-2008, 05:17 PM
Please, edit this post with some paragraphs, because my eyes hurt me when I trying to read this post, and I have 20/20 vision.:eek:

Josip
06-03-2008, 05:32 PM
Hi, George Askew :)

Welcome to RE forums...


Hi Guys I am new to the forum so Hi to you all ..................................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!) ......................Comments please.George

no comments so far;)....I believe that place and life there is nice......

Best regards, Josip :)

frank
06-03-2008, 06:49 PM
Please, edit this post with some paragraphs, because my eyes hurt me when I trying to read this post, and I have 20/20 vision.:eek:
Sorted now :)

And moved to the correct area.

nike123
06-03-2008, 07:12 PM
Thanks Frank, you are realy Site Moderator : and general nice guy.:):)

nike123
06-03-2008, 07:52 PM
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?


I think, when I was in one factory, they told me, that after welding they wash exchangers with water and some deterđent, and then they dehydrate them. I don't know any detail how they do that, but if you carefully taught every aspect of that approach, it could be your way of cleaning that exchanger.

Springbok
06-03-2008, 09:47 PM
Hi george.Looking at that exp valve,seems someone try to seal the leak with leak-lock ( the blue caotings ),if the valve was leaking.If you have experience with it,and you have it handy,try flushing the system with 141B.Its a cleaning liquid used for flushing out a system.

I've seen those containers before.I'm from South Africa and I worked for a company in Cape Town where we built containers,refrigerated them,then sent them out to Zambia.( Banana ripining rooms ) We had a few old containers which we had t "clean up" and we used 141B.

The coil looks pretty corroded,so I don't know how many years its got left.You could pressure test it for 24 - 36 hours.This always happens when they send these containers via tankers,it tends to create leaks.If you want to re-commision the system again,I would just retrofit it to R404A and change to POE oil.

Hope it helps friend......:cool:

George Askew
07-03-2008, 03:39 PM
Hi All
Thanks to Frank for editing my 1st posting. My apologies to all as it also 'hurt' my eyes.
But if anyone has time please explain this. I copied it from a word doc and it was as Frank corrected it.
When I saw the pasting it was sort of jumbled so I did some spacing, but thought that it was normal for it to appear condensed - as I have seen this in a few postings I have made in comments on other websites.

My apologies I hope I get it right next time, as I have found the site a tad difficult to navigate.

Where did I go wrong?

How do I edit that message? Because its Jungle NOT J`ungle.

How do I get the "Bubble"for comments?

Regards
George.file:///C:/DOCUME%7E1/GEORGE%7E1/LOCALS%7E1/Temp/msohtml1/05/clip_image001.gif

George Askew
07-03-2008, 03:51 PM
To nike 123
"..they wash exchangers with water and some deterđent, and then they dehydrate them.."
"
Thanks nike. Will look into it but we dont have any decent water pressure here nor a pump - nor a decent strong air supply. - and thats the whole town not just us! Dont even know if I can hire a big compressor here - then I dont have fittings and doubt if I can get them here. Like I said a "Grass-Roots" operation and everything just takes soooooo long to get or get done here.

George Askew
07-03-2008, 04:12 PM
To the Bok:
"....If you have experience with it,and you have it handy,try flushing the system with 141B.Its a cleaning liquid used for flushing out a system...."

"...re-commision the system again,I would just retrofit it to R404A and change to POE oil..."

Thanks boet. Appreciate your comments. You at least have an idea of the joys of Africa - but like I said I have been out of Refrig so long I havent even heard of these products. (I am devouring this sites old posting to try and learn more).
Where would I get the141B? How much do I need? What is so special about it? Can it be airfreighted or is it banned? {land transport is a nightmare and slooooow} [
Now why should I change the refrigerant and oil? What is so special / different about them to justify the horrid expense of getting stuff here?

This position I have was supposed to be more of a caretaking one - connect up the blast freezer , evacuate it, change drier, recharge and Hey Presto! Then just keep an eye on things. E.g Our 2 running 40ft reefers [but found one has a gas leak - we havent had electricity to run the other one for a length of time so its a ??] - the blaster and the ice-machine [I need electricity and decent water supply for that - Govt supplied! - and no doubt will have some comments for the forum on that from what problems I saw when I was able to run it for a short time.
So here I get dropped into the deep end of Funsville with no gadgets, tools,spares etc so I have to be creative (Which I am - having spent 94 & 95 in the Congo losing money diving for diamonds and recently 1.5 years in Mozambique).

nike123
07-03-2008, 04:13 PM
Go to User CP and then Edit options. At bottom you have Miscellaneous Options and select " Enhanced interface"

frank
07-03-2008, 04:50 PM
Hi All
Thanks to Frank for editing my 1st posting. My apologies to all as it also 'hurt' my eyes.
No problem with the post George, it always takes time to learn something new ;)

But if anyone has time please explain this. I copied it from a word doc and it was as Frank corrected it.
When I saw the pasting it was sort of jumbled so I did some spacing, but thought that it was normal for it to appear condensed - as I have seen this in a few postings I have made in comments on other websites.The paste and copy function appears to have lost all of the formatting :(


How do I edit that message? Because its Jungle NOT J`ungle.

How do I get the "Bubble"for comments?On the bottom of a post is a green 'Quote' button. press this and the screen will open up for you to reply with the original words in {quote} marks. I've amended the title as well :)


Regards
George.file:///C:/DOCUME%7E1/GEORGE%7E1/LOCALS%7E1/Temp/msohtml1/05/clip_image001.gif

Looks like your signature needs some work too George :D

Springbok
07-03-2008, 06:30 PM
Hey George.:DYeah,I understand the fact that you've been out of the game for a while,and because the trade is so diverse,it makes it harder to keep up with all the changes going on in this trade.

I also understand the expenses resting on your shoulders should you consider the retrofitting procedure.The only main reason I suggested to change to R404A and POE oil,is that is more easily available than R408A.

You could just keep it at R408A and POE oil,and just flush it with 141b.As far as i know,141b has been banned since 2003 in the usa,but not sure elsewhere.Also not too sure how long R408A will be around for,the replacement is Isceon 79.

I'll give you a couple of suppliers names in South Africa,and you can contact them if you wish too.They could give you more insight on the upgrade on 141b,if they'll supply it,and importantly at what cost.

Its nasty that your position and conditions by you don't always swing in your favour.:eek:Hope all the info helps,mate...:D

(1.) ACR Components,Cape Town,South Africa
+27 21 511 7101

(2.) Reco,Cape Town,South Africa
+27 21 511 9186

Gary
07-03-2008, 11:31 PM
Whichever fluid you use to clean the coil, you will need to pump it into the bottom of the coil and let it flow out the top in order to completely fill the coil (every little nook and cranny), so you will need a small liquid pump of some sort. You would pump the fluid out of the bottom (actually near the bottom) of a container, up through the coil and let it overflow back into the container. Does that make sense?

Then after you are done, you will need to seal the coil and evacuate it several times, breaking the vacuum with refrigerant vapor in between evacuations. Do you have a good vacuum pump?

Gary
08-03-2008, 12:01 AM
You could just keep it at R408A and POE oil,and just flush it with 141b.

The good news is that POE oil is highly detergent and will scrub the inside of the system sparkling clean. The bad news is that it then needs to deposit all of the gunk somewhere... and that somewhere will be the drier and/or TXV. You may need to change the oil and drier several times... and possibly overhaul the TXV as well.

George Askew
17-03-2008, 03:01 PM
[quote=Springbok;96207]Hey George.:DYeah,I understand the fact that you've been out of the game for a while,

Thanks Bok

George Askew
17-03-2008, 03:52 PM
[quote=Gary;96253]Whichever fluid you use to clean the coil, you will need to pump it into the bottom of the coil

Thanks for this Gary
G:o

George Askew
17-03-2008, 03:55 PM
[quote=Gary;96257]The good news is that POE oil is highly detergent and will scrub the inside of the system sparkling clean.

Thanks Gary:cool:

George Askew
17-03-2008, 04:02 PM
No problem with the post George, it always takes time to learn something new ;)

Looks like your signature needs some work too George :D



Thanks for all Frank - but I didnt put all this garbage on my signature - so how do I prevent it?
G

The MG Pony
17-03-2008, 04:41 PM
Methyle alcohol, or Isopropyle alcohol, or even some good stout moonshine to flush it, then warm it up and blow through with air for a bit to evapourate any remaining alcohol, then pull a vac whilst it is still hot.

I been doing this to recover used heat exchangers, I've ised a circulation pump and isopropyle alcohol with a filter to clean the coil out.

The MG Pony
17-03-2008, 04:43 PM
http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=59_201&products_id=21689 Here is a cheap yet very sturdy 12V pump.

frank
18-03-2008, 09:12 AM
Thanks for all Frank - but I didnt put all this garbage on my signature - so how do I prevent it?
G
Go into your CP (Control Panel) and 'Edit Signature' :)