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Hi Guys,
I met an engineer from Germany who was also in refrigeration field. He told me that using Ammonia in Europe is discouraged by the government. What he was saying is that there is no regulation about using Ammonia but the government places such a difficult requirements so that the designer or the owner prefers to go with CFC, HCHC, ... refrigerants.
Guys from Europe, can you elaborate on that. Is it true?
Cheers:)
Well I'm not from Europe but I do have a question.
Is the ammonia system use that restrictive, or does it seem that way because the other refrigerants have so many less requirements?
Some of the safety regulations for large ammonia systems here in the US are very stringent.
The funny thing is, a small ammonia system should have the same requirements as a large system. And, once you get past the smell issue, all refrigeration systems should be treated the same.
When you start to work with large ***** systems they are essentially no different than a large ammonia system except on two points; the smell and the panic.
Ammonia is always good for this. With the other refrigerants (say R-22) a large leak does not carry the same panic as even a small ammonia leak. However, you don't have to worry about fainting or going to sleep from oxygen exclusion with ammonia.
Ammonia does not sneak up on you the same way the other stuff will.;)
Hi, Here In England the Ammonia safety regulations for Ammonia plants seem to be very stringent. But with the new "F" gas regulations the use of ***** system's look like they may become the same.(as a Ammonia man on a large freezing and coldstore plant this is what it looks like to me.)
Arthur.
Quote:
Originally Posted by lana
In the UK ammonia has always been used in the industrial market.
Its popularity depends on lots of factors but it is not dicouraged by the govenment.
Local planning and risk assessments are required but ammonia is becomeing more and more popular in the commercial market as well because its such a usefull refrigerant.
taz.
I can speak for Belgium where the law is not that stringent: it's the installer who decides what will be installed.
But I can tell just the opposite: in Luxembourg, every plant going over 90 kg (198 lbs) of refrigerant must be a NH3 or absorption plant.
I agree with what Mike explains about the use of NH3 adnd especially the smell: everybody should work first once a time with ammonia to learn the proper way handling refrigerants in general.
Once yo have the right habits to handle NH3, and you should apply these habits for all the other refrigerants, we should have a lot less losses in the environment.
They better should add a very strong stinking smell (rotten eggs or huge farts smell :D :D ) to all the refrigerants which should stays in you clothes for some hours. :p
Thanks guys for your useful inputs.
As you all know, ammonia has incredible thermodynamic properties which are not comparable with other refrigerants. The only set back is the safety issues which can be followed and make it safe.
Anyway, the guy was from Germany and maybe he was trying to advertise the use of CFC, HCFC,...
Any other comments will be appreciated.
Cheers:)
That is a very good idea Peter. I'm serious.:)Quote:
Originally Posted by Peter
If the other refrigerants had an odor added to them more people would be MORE careful with handling refrigerants.
The odor in natural gas is added for a safety reason. Natural gas in the original form does not have an odor. I believe the chemical ethyl mercaptan is added to make the smell.
If everyone had to work with ammonia, or better yet, sulphur dioxide you WOULD be more careful.:D
The people who do not sell ammonia equipment can find all sorts of interesting (but false) information to sell their products.
And it would be easier to trace leaks! One constant thread I come across is the hours it can take to find ***** leaks with OFN on big plants. The customer is jumping up and down wanting his plant running again and, by rights, you should pump down, isolate and leak test each section to narrow down your options.Quote:
Originally Posted by US Iceman
This pressure (no pun intended) to get it going again leads to people charging plants with ***** to test for leaks using a sniffer just to speed up the process and get the customer off their backs.
Surely this is a case of legislation running too far ahead of currently available practice. It is OK when you are working on a split and only have a few joints. Big (like 1000kg plus) ***** plants are a different matter and I can't help thinking that the law-makers didn't take a big enough step back to consider all the implications.
So, who does "smelly" OFN or another inert gas that would fire off some kind of detector......?
Steve
I think the odor should be in the refrigerant. That would save a lot of time and trouble initially and afterwards when trying to find the leak. It would also offer an initial alarm that something is going wrong.Quote:
Originally Posted by SteveDixey
I think one of the biggest hurdles will be the refrigerant manufacturers themselves. For over 30-40 years they have advertised their refrigerants as odorless or as a slight ethereal odor (as a safety benefit no doubt).:rolleyes:
Someone would have to prove to me that some of this legislation is not done in the interests of refrigerant manufacturers. If there are no special interests involved, then it should be relatively easy to get the odor in the refrigerant.
There have probably been more people killed by the HFC's, HCFC's, etc. than ever killed by an ammonia system. You will simply not stand there and breathe it for very long, where the other stuff you may breathe it for hours before you begin to notice it. At that point the damage is mostly done.
If the plant has emptied itself over a weekend shut-down, (no on-site refrig techs, not an uncommon scenario for halocarbons), you still need smelly test gas because charging halocarbons into a system known to be leaking is an enviromental no-no. In the UK, you are supposed to assume an undercharged system is leaking unless you can prove otherwise.Quote:
Originally Posted by US Iceman
Bigger fixed systems are supposed to have leak monitoring systems fitted but Murphy's Law says the leak will occur somewhere else, like in the middle of a condenser tube stack.....:confused:
Steve
I would agree with that. So... it seems we actually have two requirements where the smell would be helpful.Quote:
Originally Posted by SteveDixey
And something that a lot of fridge techs would like now.Quote:
Originally Posted by US Iceman
A few have used ultrasonic testers but they are only useful if there are no other leaks in the vicinity (show me a working factory with no air or steam leaks and I'll show you a flying pig :rolleyes: )
Steve
:D :DQuote:
Originally Posted by SteveDixey
Just when I thought I had seen it all.
I bet the flying pig is more common than we think.
Just think how many times we have heard the comment "Not me".:rolleyes: Never a culprit to be found, yet it happens.
Mike, the more it leaks, the better for the manufacturers.Quote:
Originally Posted by US Iceman
I still charge a leaking system with some HC to find the leak.Quote:
Originally Posted by SteveDixey
I feel that it is better to find the leak asap then following the law precisely. And if I have to use then some HC for it, then it will be so. As long as there are no othe reliable and quick methods, I will do it this way.There's no other solution for the moment.
I personally find that the cure is better then the outcome (not finding the leak and recharging it anyhow)
We installed last months 19 outdoor units of Mitsubishi.
How we leak tested these?
Well, we first vacuumed them all each for +/- 1 hour with a digital vacuum gauge in line with the vacuum line. You then see very fast - within 15 to 30 minutes - where you have forgotten to tighten some nuts. This costs nothing, just some electricty.
If we then achieved a reasonable vacuum, and we could suppose that the system was airtight, we then pressurised the system with 10 bar (145 psi) OFN and let it there for a weekend.
After the weekend, those who their pressure was stable were further pressurised till 25 bar (360 psi) for 2 days.
Those who dropped more then 0.2 bar (7 psi), released the OFN, add some tracer gas in it (R404a) till 4 bar (58 psi) and pressurised further till 25 bar (360 psi)
Searching for the leak, releasing teh pressure, repair it (2 in the Refnets!!) and re-pressure again till 25 bar (360 psi) for 2 days.
Then vacuum the system till at least 50 Pa.
Hi guys,
Interesting .....:rolleyes: :rolleyes:
But I think this thread is drifting from its original idea :confused: :confused: :D :D
I will keep reading anyway.
Cheers
Yeah, the threads have a way of doing that now and then.Quote:
Originally Posted by lana
The original question was a valid one, and I'm anxious to find out more on this also.
I'm a little bit skeptical of claims others make when ammonia is concerned. I have seen too many attempts to get it "black-listed" because it does not fit with the marketing plans of others.;)
Hi USIceman,
I am in "*****" business not ammonia, but I agree with you completely. Some people try to dis-advertise, if you like, for something they don't make money with or it is their competitor.:mad: :mad:
But in reality both refrigerants have their advantages and disadvantages.
I also would like to know the real situation in Europe or in the world for that matter.:confused: :confused:
Cheers:)
Hi Guys
I don't know about Yours countries but in Italy, the only idea of use Ammonia already give a headache :eek: :eek: As to get the license to handle toxic gases You need to
go to the shrink to say that You are not crazy
go to the doctor to say that Yuo are healthy
pay few Euro of taxes and fee (the gov always wanna be part of your life and let You know that they love You..)
do an exam with fire Dep.t
All this for an approx time of two months, whoops and every five years... Same process again.... :confused:
All the NH3 industrial plant need to meet explosion proof requirements... Instead for the ***** plants..... almost nothing..... Guess for which plants customers and contractors are going?? Well done!! *****s!
Also if I don't agree because I think that Ammonia is the an old technology ready for the future as well....
Evapcoil
Several years ago, I was working on a large chemical plant in the US which was owned by a German company. The system was designed well beyond normal US standards as was typical of most chemical plants. During the meeting which had two corporate engineers from Germany, they proceeded to tell us that the Americans knew absolutely nothing about designing a system for the safe use of ammonia and our codes and standards were all wrong. We were to follow the German codes as a minimum.
With such and authority telling us what to do, I simply told them it was their check book and I would be more than pleased to help them empty it.
The German parent had initially pushed for an R-134a system and the local plant had insisted on ammonia.
Ken
Your design was or theirs was Ken?Quote:
Originally Posted by TXiceman
The US practice in chemical plants is nothing to sneeze at (which I know you are aware of), unless someone is trying to build it to a nuclear code!
What is more stringent than B31.3, etc. Unless you get into power piping?
This sounds an awful lot like a difference in interpretations!
Hi Guys
I just want to say that i don't know about US standards but in Italy , only mentioning the word Ammonia give goosebumps even to the most capable designer, only because all the burocracy and stupid rules that We have... As I had already say , don't takes me wrong, I would love that NH3 will become more popular in Italy...
Mike, the system design was mine, but we were meeting ANSI B31.3 for piping, ASME Section VIII (did not use the para UCS 66 exclusion), and evaporators per TEMA R and other heat exchangers per TEMA B. All piping and valving was carbon steel or the correct alloy per 31.3.
A big discussion came on the the effect of "auto refrigeration" and the effect of cold on the piping system n the event of a massive rupture. They wanted the entire system to be alloys suitable for -40 dF. They could not understand the fact that in the event of a rupture you will not have high pressure and low temperature at the same time. The physical laws and properties of the refrigerant will not allow this unless by some freak occurrence, you manage to pressurize a vessel with a pool of -28 dF liquid which you can not get to unless the liquid has been at atmospheric pressure.
We eventually got adds to design the system with low temp alloy of Charpy impact tested steel designed to 300 PSIG at -40 dF to 400 dF. This was for a system on the US Gulf Coast. I had designed systems going to the North Slope that had to meet the low temp materials due to the ambient during the winter.
It was a nice profitable job thanks to the added cost at the customers insistence.
Ken
NH3 because of its noxious smell often gets bad press if and when it escapes; here in NZ where it is used extensively in large freezer plants, the incidents are few and far between.
It is by far the most energy efficient refrigerant in general use and its high Latent Heat value reduces the refrigerant mass /TR required .
So in a world ; NZ in the forefront, where the use of energy , is being threatened with a "Carbon" tax, ammonia as the preferred refrigerant should be all the more encouraged .
Due to the stringent requirements by most states regarding design , installation, the costs have to measured against alternatives so that it is commercially acceptable to the end user but once installed and operating, provided that the plant is properly maintained by competent engineers the operational life will surely repay the initial cost in operational costs and performance