refrigerant

[Steve]

R404 in particular. What happens when its burnt?

A guy came to swap out a compressor at our shop, in an open-top freezer. Someone had cut the cables too short underneath, so he couldnt get the compressor trays out and had to do it all laying on his back.

I've seen a few compressor swaps before, but this was ridiculous. He had to put bags over the smoke detectors. There were bits of black soot flying everywhere. Clouds of smoke and loud pops and flashes coming from where he was working.

I asked what he was doing and he said it was the refrigerant burning off. He had vacuumed the system before he sweated the compressor off, so why was there any refrigerant to burn off when he got his oxy-acetylene out?

The smell was horrendous, very offensive, and there was a woman walking around with a pushchair asking if it was safe, the guy said "as long as you dont breathe too much in" Muttered something about nerve gas to me.

Anyway, the freezer now works, but im forever finding chunks of black soot on top of the shelves.

 

[bernardgreen]

I suspect it was more the oils from the compressor that was burning. The gas would just evaporate.

 

[tim west]

And an even bigger hole up there

 

[Steve]

And an even bigger hole up there

Nope, R404 (might have been 410a) isn't an ozone depleting gas. Even so, the system was vacuumed beforehand and as bernard said, it was probably the oils from the compressor that were burning.

 

[tim west]

sorry Crafty but reading the above i couldn't make the connection between the R404 and what was next said, So i commented regarding the system containing CFC's. was the refrigerant in that particular system R404? or was the OP generalising?

 

[racket]

When a compressor has been off for a period of time the oil absorbs the refrigerant gas, so when the heat is applied when he unsweats the pipe the gas will leave the oil and when it escapes it is burnt by the Oxy torch.

The black soot was from his oxy set, he should have opened the accetelene and the oxygen together before lighting his torch, he must have just lit the accetelene which gives off a lot of soot.

He should have reclaimed all the gas properly with a reclaim unit, then he should have cut the whole stub off the compressor and removed the compressor. This would then leave him just the stub on the end of the pipe to unsweat, and because there was no oil or gas present you wouldn't get the nasty smell, by the way when the old CFC gases were burnt in a naked fame they produce Phosgene gas

The guy who did it sounds like a bit of a cowboy to me, he didn't reclaim all the gas properly, it is illegal to vent any refrigerant to atmosphere.

 

[empip]

Don't worry, we are but a droplet in the ocean !

Demand exploding in India, China for air conditioners that use chemicals being banned here...
... Keith Bradsher New York Times
MUMBAI - Until recently, it looked like the depleted ozone layer protecting the Earth from harmful solar rays was on its way to being healed.
But thanks in part to an explosion of demand for air conditioners in hot places like India and southern China - mostly relying on refrigerants already banned in Europe and in the process of being phased out in North America - the ozone layer is proving very hard to repair...

Industrial countries currently must phase out production of HCFC-22 by 2020 and are ahead of schedule, with the United States banning domestic production in 2010. The Environmental Protection Agency is studying whether to ban imports of the gas and sales of new products using the gas by then as well.

By contrast, the Montreal Protocol, which governs the phase-out of ozone-depleting chemicals, allows developing countries to continue using HCFC-22 through 2040.

China, in particular, is stepping up exports to the United States of air conditioners using the chemical, often labelled as R22, especially after the European Union finished phasing out the production and import of such air conditioners in 2004.

Pound for pound, HCFC-22 is only 5 per cent as harmful to the ozone layer as the chlorofluorocarbons it replaced. But it still inflicts damage, especially when emitted in enormous quantities by China, now the world's dominant producer of window air conditioners, and by India, a fast-growing market and manufacturer.

The latest estimate from technical experts is that output of the chemical in developing countries is rising 20 per cent to 35 per cent each year and could continue at that pace for years: slightly over 2 per cent of Indian households currently have air conditioners, according to LG Electronics of South Korea, a giant maker of air conditioners...

In China, ownership soared to 87.2 air conditioners per 100 urban households in September, from 24.4 seven years earlier. The countryside, home to two-thirds of the nation's population, is poised for even greater growth. In 2005, there were 6.4 air conditioners per 100 rural households, a 35-fold increase from a decade earlier...

... Developing countries like China and India enjoy exemptions from global environmental standards. The Kyoto Protocol, which governs emissions of global-warming gases, is also lenient toward them, on the grounds that industrialized countries have released the great bulk of the offending gases and poorer countries should be allowed to catch up economically before taking on additional environmental costs.

Ah, the lynch pin -- 'developing country' -- As in 'do not deny development by imposing expensive methodoligies for reduction of harmful emissions.'

The great governmental balancing act, curb the great industrial west, whilst allowing the east to proliferate ... Whilst their labour costs are less of course...
This could all end in tears.
When the levelling begins to hurt will the door spring open for extreme government? Perhaps mankind is writing the final chapter(s)....

 

[Steve]

When a compressor has been off for a period of time the oil absorbs the refrigerant gas, so when the heat is applied when he unsweats the pipe the gas will leave the oil and when it escapes it is burnt by the Oxy torch.

The black soot was from his oxy set, he should have opened the accetelene and the oxygen together before lighting his torch, he must have just lit the accetelene which gives off a lot of soot.

He should have reclaimed all the gas properly with a reclaim unit, then he should have cut the whole stub off the compressor and removed the compressor. This would then leave him just the stub on the end of the pipe to unsweat, and because there was no oil or gas present you wouldn't get the nasty smell, by the way when the old CFC gases were burnt in a naked fame they produce Phosgene gas

The guy who did it sounds like a bit of a cowboy to me, he didn't reclaim all the gas properly, it is illegal to vent any refrigerant to atmosphere.

I'm not sure now, the age of the freezer is unclear. It looks pretty new, and came to our shop in 2005 during a refit, with instructions and QC certs etc. But it is second hand according to the guy who changed the compressor, as it has been worked on before (wires on compressor trays cut too short). So it might have had old refrigerant in it, with the new compressor being charged with new gas.

I take it Phosgene was the puffs of smoke and nasty smell, I think this was the name he mentioned to me.

 

[racket]

I cant see it being on the old gas as 404A came into use around 1997, More to the point if it was on the old gas the system used a mineral oil and the new gas uses a synthetic oil and you cant mix them, if you do the oils turn to a wax and knacker your compressor. Look for an identification plate on the cabinet,the old gas was R22. If the plate says R22 and he is fitting a 404A compressor then he needs to flush out the complete system, this is an expensive and time consuming job.

good luck

 

[Softus]

Perhaps mankind is writing the final chapter(s)....

 

[Nige F]

Phosgene Mustard Gas sure it wasn`t Zyclon........like they named the fairground ride on Brighton Pier once .........in 5 foot high neon letters.......didn`t stay there long

 

[joe-90]

That's a 'cyclone'. Zyklon B was used to delouse clothing in WW11. It was rather ineffective.

 

[ricicle]

That's a 'cyclone'. Zyklon B was used to delouse clothing in WW11. It was rather ineffective.

And to gas millions of innocent people it was very effective at that

 

[empip]

Invented by a Jew ... too.

Perhaps they should have spent some of their undoubted wealth on soap for the poor ... Could have changed history.
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