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deepakrbhat
09-04-2004, 11:08 AM
hello
i am trying to build a low capacity ammonia refrigerator,which could be used to manufacture ice.is this possible? the idea is to charge an open type compressor(say a gun metal compressor,so that ammonia doesent react with it), use aluminium pipes all round, aluminium evaporator and condenser.waht are going to be the possible areas of failure? why has ammonia refrigeration not been done on a small scale till date(or has it been done?)?

Peter_1
09-04-2004, 01:06 PM
IS already done many time.
Small chillers which cool brines or a secundary fluid and then pumped around to cooling coils in meat processing.

Andy
09-04-2004, 09:32 PM
deepakrbhat :)
how small is small.
10kW 100KW
size is relative :D
Regards. Andy :)

deepakrbhat
10-04-2004, 03:10 AM
thank you for yuor response.
small is something in the range of 1 to 2 kW.well if it has been made before then should not have much problems.
thanks again.
deepak bhat

Latte
10-04-2004, 05:02 PM
Can sombody explain to me the advantages of an ammonia system as opposed to an HCFC system. I have witnessed first had the effects of a leak, It laid my boss out better than mike tyson could. I don't like the idea of ammonia purely fo this reason, is it far cheaper to install & run or am i missing something.

Regards

Raymond

RogGoetsch
10-04-2004, 08:31 PM
Can sombody explain to me the advantages of an ammonia system as opposed to an HCFC system. I have witnessed first had the effects of a leak, It laid my boss out better than mike tyson could. I don't like the idea of ammonia purely fo this reason, is it far cheaper to install & run or am i missing something.

If memory serves, ammonia is thermodynamically a better refrigerant than the halocarbon-based. Add to that its relatively low cost, ease of leak detection and its environmental friendliness (add water and it's fertilizer). It also cleans out your sinuses, drives annoying people away and kills foolish people, thus increasing the average intelligence of refrig techs in general, always a good thing!

One thing to remember is that under most codes, it cannot be employed where people congregate. As I recall, codes in California do not allow it to be used in any confined space with an occupancy denser than one person per 100 square feet, effectively limiting its use to industrial applications.

According to my first instructor, the danger from an ammonia release is not so much from the ammonia itself as from people trampling others in their panic to escape.

In his lifetime of ammonia work, he had known of only one fatality: a tech draining oil from a receiver who took a leak directly in the face, jerked his head back and knocked himself unconscious on a pipe. The tech was alone at the time and was not discovered until his body had been partially frozen by the leak dripping on him. If not unconscious, you will flee the area due to respiratory distress long before you will be overcome.

A water spray will mitigate the effects of an anhydrous ammonia release since it will become ammonium hydroxide, hopefully before it finds the moisture in your lungs!

How did your boss get knocked out?

Rog

Latte
10-04-2004, 10:19 PM
From what i can remember, We were all working at at transport company that operates four very large coldstores. One had a leak and as he was walking accross the yard it hit him. I'm faily sure he wasn't actually knocked out but suffered breathing problems. If Grabber01 is reading this he knows the person very well and maybe able to give you more information.

Regards

Raymond

deepakrbhat
11-04-2004, 03:03 AM
well thanks !
the advantages of ammonia have been clearly stated by rdocwra,to which i can onlly add the emphasis to the ecofriendly nature of ammonia.i do know the the immediate argument to this would be to use either R134a or others,but it does seeem to be the future of refrigeration.as soon as the global warming and ozone depletion problem become reallly serious,people will have to start looking for different alternatives.
also one must know that ammonia is hazardous only when it is about 330ppm in still air covering 100sq m area.
in developing countries the laws regarding ammonia are not all that stringent and thus it allows freaks like me and my friends to try out things like this.
the attempt here is t cool a secondary refrigerant and to use this to cool small chillers used in malls ect.the compressor unit need not necessarily be close to the cooling area.
if anyone one out there knows about the technical difficulties faced in using ammonia then plz help me with your valuable comments.
thanl you once again.
deepak bhat

Peter_1
11-04-2004, 07:30 AM
Everybody can dowload the compressor selection software of he German Bitzer compressors which are one of the best available in Europe (in my experience)
You can simulate a screw or piston compressor working on let's say R404a and NH3.
Have a look at the COP when evaporting at -10°C and -30°C (same condensing temperature of course) for both gasses.
COP is not better (even worser) when using it for freezer applications.

chemi-cool
11-04-2004, 03:01 PM
I only know ammonia, used as a fertilizer, even then, the smell is one of the worst.

those who get the kick by pushing their luck to the limit, fine with me.
I will keep a good distance.

I like your story rog, its all right and safe untill...........
I wonder how many good techs, lost their lives in the fumes of ammonia.

for those who insist of doing it, bare in mind that someone is waiting for you to come back from work. work very carefull.

chemi

baker
13-04-2004, 07:54 AM
I live in a modern city of 1.2 million and NH3 plants appear to be spread around without much concern. An inner suburban factory that I have toured uses 60 tonnes of NH3 and is surrounded by housing. I find it amusing that its neighbours worry about cellular phone towers, and are always protesting to get them moved, but are oblivious to the ammonia.

As mentioned previously, NH3 has great thermodynamic properties and is cheap. I would hate to guess the cost of 60 tonnes of R404A. Its hydroscopic feature can easily destroy eyeballs. A blast of NH3 to the eyes will extract all the water from them immediately, destroying the eyeball.

Although R717 cannot be used with brass or copper, R723 is an azerotropic mixture of ammonia and diethyl ether and can be used with these metals. It is still rated B2.

Personally, I think that the NH3 industry has been lucky. They would be such as easy target for "safety ratbags".

Andy
13-04-2004, 06:24 PM
[QUOTE=

those who get the kick by pushing their luck to the limit, fine with me.
I will keep a good distance.


chemi[/QUOTE]

Chemi
BULL****, R717 is only a little less safe than R22. R22 will gas you without a warning, NH3 lets you know where the leak is. You can only be harmed with NH3 if you break into a system or something fails. When breaking in properly trained techs will pumpdown and purge into water, then finally purge with nitrogen. Only fools open the valve and let rip :mad:
Statements like this are what hinder progress, I have never had an incident with NH3, but I have been overcome with fumes from ***** plants.
NH3 plants have proper leak detection and ventilation, how many ***** plantrooms have this :confused:
Retract your comments or face the wrath of NH3 techs everywhere :D
Kind Regards. Andy. :)

Mark
13-04-2004, 06:30 PM
how many ***** plantrooms have this

Quite a few actually Andy ;)

chemi-cool
13-04-2004, 07:03 PM
hi andy,

nothing personal, I'm glad to see that you have pride of your work.

NH3 plants have proper leak detection and ventilation

here is the answer! you have to have leak detection! this is the difference.

I will never install an air conditioner in a place below ground level from that reason.

I'm sure andy that you will never have a serius accident because you do not make short cuts during your work, but how many techs do?

I think that in all my working years, the amount of R-22 that went through my lungs, can charge a 20 ton unit and i'm at tip top phisical condition. would I survive breathing 1/1000 of the amount if it was R-717?

driving on the roads here, is the most dangerous thing I do.

chemi :)

deepakrbhat
13-04-2004, 08:17 PM
hey guys
your discussions are proving to be helpful.this is wat i have done till now.
i have selected a standard open type R22 car AC compressor, built up the entire unit with pipings made of aluminium, twin condensers which are to be water cooled,a standard cooling coil of Al,the setup is ready but now is the major problem!ammonia in my area ia available in large quantites (cylinders of 40kg at very high pressure) and i definitely will not be able to take the risk of charging 100gms of ammonia from such a huge tank!
well the search for small ammonia cylinders does continue

plz suggest
thanks

Andy
14-04-2004, 09:50 AM
Hi deepakrbhat :)
NH3 is available in smaller quanities from companies that supply laboratories and others for scenitific use. Try BOC gases.
Receiving NH3 through the post will be a problem.
You have yet to understand the temperature pressure relationship.
200 grams of NH3 will be at the same pressure as 200kG in the cylinder sitting beside it. :)
Best of luck.
Kind Regards. Andy :)

Andy
14-04-2004, 09:53 AM
Mark,
supermarket all or nearly all use leak detection and ventilation. Industrial ***** plantroom usually don't. This is one are that commercial refrigeration is ahead od industrial refrig.
I would fing it hard to think off one industrial plant I have worked on that has leak detection (I can only think of two).
Kind Regards. Andy. :)

chemi-cool
14-04-2004, 02:36 PM
hi andy,

dont ammonia attacks aluminium?

chemi

deepakrbhat
14-04-2004, 05:46 PM
hey andy
thank u. i will look up for people selling chemicals to colleges/labs in the yellow pages.well about the pressure temp relationship , what i ment was that the pressure in the 40kg cylinder is too high for my small capacity plant(i want to restrict it to around 7-8bar) is there any way in which i can transfer ammonia into a small cylinder at lower pressure?

well about reaction of ammonia with aluminium,i have tested aluminium fillings with liquid ammonia and there hardly seems to be any reaction (the size of the aluminium particles has been the same,it has been around 2 months) havent found any documentation on any serious reaction of aluminium with ammonia.in fact "Mycroll" in colaboration with Hitachi air conditioners have already buit a hermatically sealed compressor for ammonia made of aluminium.
thank you.

chemi-cool
14-04-2004, 06:28 PM
hi deepakrbhat,

all you need is a small container that can hold the presure, vacum it, freeze it and you can fill from a larger gas bottle liquid wise.

check that weight is ok and there you go.

I've started to read and leard about ammonia refigeraition on the www
but everywhere they write about the death toll, impressive numbers!

andy - "BULL****, R717 is only a little less safe than R22"
is not exactly right but give me some time and I will gain some more knowlege on the subject.

chemi

Andy
14-04-2004, 08:41 PM
Hi deepakrbhat :)
Aluminium will be fine. Don't do as Chemi says, if you vaccumn the cylinder and add liquid the thermal shock might damage the cylinder.
Just lower the the pressure in the large cylinder by cooling it.
The pressure in the small cylinder at room temp will be the same as the large cylinder :o NH3 at 10.5barg is approximatly 30 deg C saturation,regardless of what vessel you put it in.
lower the temperature of the cylinder to 10 degC and the cylinder will be at 5.1barg :)
When designing the system decide on a PS or allowablw pressure and select components to suit, say either 17barg or 20.7barg or 25barg.
Pressure test to 1.1 to 1.3 times that, not exceeding the maximun allowable pressure for each component.
Evacuate the system to 100 micron or below and add first gas not liquid until above -10degC saturation, then add liquid to the minimun that the system will safely run at, adding there remaining charge as required.
Word or warning, were propper protective gear, work in a well ventilated area and if possible employ a good refrigeration Tech to do the charging.
Also please fit a pressure relief valve that vents outside the area you are working in (set to the PS) and all will be fine.
These rules apply to all refrigeration systems, but people take short cuts and get away with it with *****.
Happy inventing :D
Kind Regards. Andy. :)

Peter_1
14-04-2004, 09:04 PM
I have to disagree Andy and follow Chemi.
I will explain why.

When I was younger, my colleague and I were working on a ammonia evaporator (shell and tube) We were plugging off temporarily some leaking tubes.
Valves were shut off but for some reason – never found out why – there was a sudden vent of +/- 2 seconds of ammonia out of the tubes.
He felt backwards and in 30 seconds, blood was coming out of his nose and mouth.
He was at home for months.
With R22, he should just feel a little bit dizzy and after 5 minutes continuing his job.
Not dangerous?

Another story: we had some years ago a leak on an ammonia PM valve (broken flange) We couldn’t come closer then 30 ft around the PM to shut off the valves. The guy who did had to dress him in a special suit wit an oxygen mask and we had to spray him under water while he was shutting off the PM.
If it was R22, we perhaps needed oxygen but no special suit , nor spraying on the guy.
Not dangerous?

Another one: at Mac Cain in Ostend – a food processor – they had a serious leak on a discharge tube to the condenser. Result: fire brigade had to come, factory closed for 2 days and neighbours all had to move for a day. Even the Civil Protection Brigade (a special section here in Belgium when there is a disaster) had to come.
If it was R22, well.. perhaps the ozone whole a little bit bigger, but the same day, they should work again.
Not dangerous?

I know that when I’m working on an ammonia plant, I’m always very prudent and always double check what I’m doing. I know that accidents can’t sometimes not been foreseen.

Last week I had to replace a faulty CVP on a bypass between hot gas an liquid out of a freezer (hot gas defrost) I had a gas mask on but even then, I felt the twinkling on my skin of the ammonia vapour (no liquid) when venting only 1 ft of ½ lines.
I left it for -15 minutes before continuing.

Anybody already tried the Bitzer software for screws or reciprocating for a freezer application? CIOP is worse for ammonia till evaporating at -15°C. Advantages??

So what’s then the advantage? I know some and those are for some the most important reason to justify the use of it: there is in Belgium between those companies who still install ammonia systems a silent agreement to skyrocket the prices of ammonia systems.
It has become a privileged section of refrigeration where they dare to ask the double of wage to the clients and they always come with 2 man, so 4 times the normal price.

Andy
14-04-2004, 09:23 PM
Hi Peter
glad I stimulated some debate. Different classification for R717, sure it is more danagerous than R22, but how danagerous is R22 :( people underestimate the danger. R22 has been proven to cause Cancer in lab rats when mixed with oil. Many people have been gased with R22 on ships, I can think on one sad case where three chineese sailors were gased in Ireland, trying to save a guy who had been overcome.
If you can fit 1/4" service valves on areas to be serviced on NH3 systems the gas can be blown off into water, then the section purged with nitrogen to flush out the remaining NH3 into water, no smell or little. Masks are for escape purposes, if you are wearing a mask to service you are in danger :(
this is an unsafe practice. Also on the service valves, all valves need kitted or repair every 5 years, if a valve is never serviced it will not hold when you need it :(
With regards to the large leaks evacuating areas this is down to poor maintenance.
We charge the same price for any tech NH3 or *****, but as you say two people are required whwn breaking into NH3 systems, this should be the case when breaking into any system, you must minimise the risks ;)

As for NH3 system prices, yes NH3 is more costly, but I cannot see prices being artificially increased, market forces would not allow for this.
We will quite willingly sell NH3 systems in Belgium, if prices are so high :) :)
with a finders fee for an valid introduction :)
Kind Regards. Andy. :)

shogun7
14-04-2004, 11:40 PM
Ammonia is an economical choice for industrial systems. Although ammonia has superior thermodynamic properties, it is considered toxic at low concentration levels of 35 to 50 ppm. Large quantities of ammonia should not be vented to enclosed areas near open flames or heavy sparks. Ammonia at 16 to 25% by volume
burns and can explode in air in the presence of an open flame.

Also in the installation of this equipment consideration must be given to oblique X-ray photographs of welded pipe joints and ultrasonic inspection of vessels may be used to disclose defects. Only vendor-certified parts for pipe, valving, and pressure-containing components according to designated assembly drawings should be used to reduce hazards. In adition, only certified pipe welders should be allowed to weld up the pipe and fittings. Cold liquid refrigerant should not be confined between closed valves in a pipe where the liquid can warm and expand to burst piping components. In addition all piping should be installed to proper piping practices for refrigeration.
Roger

Peter_1
15-04-2004, 08:45 AM
Hi Peter
...sure it is more dangerous than R22, but how dangerous is R22 :( people underestimate the danger. R22 has been proven to cause Cancer in lab rats when mixed with oil. Many people have been gased with R22 on ships, I can think on one sad case where three Chinese sailors were gassed in Ireland, trying to save a guy who had been overcome.

Heard same story but this - I think - it's not related to R22 but to the fact that 'the' gas (R22 in this case) has pushed away the oxygen for breathing.
It - R22 and many others - gives perhaps cancer but if you should inhalate the same amount of ammonia, or even a fraction of it then you shouldn't have any chance that you had ever again cancer :eek:
All that lab tests with mices is when they're exposed for long time (days, even weeks) to gasses.

We had in Belgium a deadly accident (cancer) with a leaking gas (R114 as far as I can remember me) hose in a big crane. There was a central cooling unit which cooled R114a as a secundary fluid which was then pumped to small coils in the cranes. Due to the long exposure (talking now of months and months) 1 died and two others had seriously cancer. Happened +/- 8 yeras ago.




If you can fit 1/4" service valves on areas to be serviced on NH3 systems the gas can be blown off into water, then the section purged with nitrogen to flush out the remaining NH3 into water, no smell or little. Masks are for escape purposes, if you are wearing a mask to service you are in danger :(

Will make a picture this afternoon of that specific CVP I had to replace.
Even the spindles of the shut off valves are leaking when you turn on them.

Installation was build in 1985 and they only call when something is going wrong. When you want to purge, you need two connections. I'm lucky if I have one service valve, if the ammonia don't comes out the spindle when opening the cover, and finally, if that SV closes firmly.


this is an unsafe practice. Also on the service valves, all valves need kitted or repair every 5 years, if a valve is never serviced it will not hold when you need it :(

It's because it's not safe I'm wearing a mask.


With regards to the large leaks evacuating areas this is down to poor maintenance.

Not at all: in the case of the discharge leak, someone hit it with a reach truck.
In the other case, you can never foresee a fault on a PM or you should replace it every 5 years or so. But even then, it always remains possible that even a new one will fail.



We charge the same price for any tech NH3 or *****, but as you say two people are required when breaking into NH3 systems, this should be the case when breaking into any system, you must minimize the risks ;)
To give you an idea, we charge 35 €/hour for servicing, the ammonia guys charge +/- 60 €/hour.


As for NH3 system prices, yes NH3 is more costly, but I cannot see prices being artificially increased, market forces would not allow for this.
Market force will allow it if you're like in Belgium only with a few - I think +/- 5 to 8 companies - who still install ammonia systems.

deepakrbhat
15-04-2004, 04:58 PM
hey thanks guys
the developement uptil now,i have found an experienced tech who is ready to charge ammonia for me.there is a small sacle industry that is ready to give ammonia in small quantities.
about the debate that has been striied up.plz be kind to note that all the stories about 100's of tech having lost their life behind ammonia no doubt is true,but in my case i intend to charge not more that 100gms of ammonia.i intend to make really small unit,(like the ones used for household puroposescapacity not more than 1 kw)
the unit, i intend to keep in a 1680 ftcube area(14*10*12)ft even if all the gas is to leak from the system the effective ppm of ammonia in the room will be really small.plz note that ammonia is hazardous only if the air contains 330ppm of ammonia.
well the advantages of ammonia:the most crucial factor is that the refrigerants used 40 years ago have caudes a huge hole in the ozone layer!the number and quantity of refrigerants used after that time have only increased exponiantially.ther is potential danger to the ozone from the halocarbons that we have over the years used as refrigerants.
the ozone depletion potential of ammonia is "zero" this makes it a refrigerant which has to be most researched upon and tried to implement(of course not at the stake of human life,which can dely be avoided if proper precautions are taken)it is definitely the the best refrigerant (highest COP)list of advantages of ammonia:
High enthalpy of vaporization.
High COP.
High refrigeration efficiency.
Large range of operating temperatures.
Low cost.
Available in abundance.
Easiest leakage detection.
Not miscible in oil.
Less energy of reaction
well it is toxic and dangerous but i definitely feel that without these small time trials like the one i intend to do,it will definitely be difficult to create a planet that is safe from ozone depletion.
thanks again and i will keep updating u guys on the developments.
kind regards
Deepak R Bhat

david.findlay
15-04-2004, 08:09 PM
Ammonia is without doubt the most efficient refrigerant known, (I believe it has a lot to do with it's very low surface tension). It is cheap, ozone benign, & has no GWP & lets face it you know when you have a leak!!!
Accidents happen when untrained engineers apply there normal working practices or experienced engineers become complacent.

Long Live NH3!!!!

frank
15-04-2004, 08:21 PM
Hi Deepakrbhat

Have you made a Will?? :p

Latte
15-04-2004, 08:45 PM
Hello All,
Whilst i see the advantages of ammonia, i believe it will never be used for anything apart from industrial uses as it now is and therefore will see little in development.
Could you imagine it ever being used in offices/supermakets ect. All you need is a leak and then the whole site would have to be cleared.
Yes, perhaps i am a chicken but having to wear gas masks working on a plant does not appeal to me.

Good luck to you guys out there working on it, you certainly earn your'e money. I will stick to the gases.

Regards

Raymond

Andy
15-04-2004, 09:19 PM
Hi Raymond :)
er R717 is a gas some of the time :D :p
The point is you should use the mask for escape purposes only, not for routine servicing :( if you have to don a mask something is defective, either a shut of valve or a proceedure :rolleyes:

Frank,
must make a will :D :D never thought working on R717 was such an issue, it's not like propane or something dangerous :D
Kind Regards. Andy. :)

frank
15-04-2004, 09:44 PM
Andy

:D :D

Latte
15-04-2004, 09:50 PM
Hello Andy,
Sorry i meant proper gas R404/R134/R22, not that old smelly stuff you use.

Regards

Raymond

Latte
15-04-2004, 10:44 PM
Good evening Grabber01,
just seen your'e name pop up as being online, about time i caught you on at the same time as me. I know how much of a fan of ammonia you are any comments.
PS how are you coping in your'e area or are you running backups at weekends as well :D

Regards

Raymond

jg/oz
16-04-2004, 07:26 AM
Raymond, there is a new refrigerant out called R723 which is 60% NH3
and 40% de-methyl-ether supposed to be better oil mixing and also capable in small plants, Frigopol Austria has installed a number of plants with the fluid
and was very sucessfull.

It is even usable if moisture content is kept low (below 1000 ppm) for copper as far as I know. The ILK Dresden ( Uni) designed the fluid.

Ozone zero ,GW zero

have a look at the ILK website

jg/oz

Andy
16-04-2004, 09:16 AM
Hi jg/oz :)
R717 can be used on copper if you can keep the moisture levl down low :D :D
don't think I will bother trying that :eek:
Kind Regards. Andy.

Peter Croxall
16-04-2004, 09:31 AM
Hi Rdocwra,
I beleive that in the states they are using NH3 in residential units. Possibly a type of absortion unit.

Peter Croxall
16-04-2004, 09:42 AM
Hi Andy,
I agree with you. It's the level of skill of the engineer that's important. All refrigerants are dangerous if not treated with respect. I've worked on many units in the past with highly toxic refigerants in them, i.e. R40 and SO2, and I am still here to tell the tale.

NH3 is a fantastic refrigerant, but should be treated with respect. We had a plant at Britsh Aerospace ( Vickers Armstrong in those days) that always smelled when you went into the plant room. They were open type compressors and I guess the mechanical seals used to leak a bit. I had alot of respect for the guys who worked on that plant. It was a stratoshere chamber by the way and it could pull down from 200 deg F to - 40 in a couple of hours.

:)

Peter_1
16-04-2004, 08:23 PM
Andy (and others)

Here's the picture of the CVP I changed.
You can see at the rest of the system that its condition is not that good.

On the second picture, you can see the service valve.

Peter

jg/oz
17-04-2004, 07:17 AM
Andy,
I told about R723 which is a azeotrope with 2 fluids NH3 and de-methylether, the substance smells like NH3 but mixes very well with oils, NH3 does not.
This allows smaller equipment to be used ( smaller commercial aplications with this fluid and have Nill Ozone and extreme low GW damage.
As you will know NH3 can be smelled at 3 ppm (parts per million) which is bugger all but any NH3 palnt you enter smell because always some NH3 is around.
One of the reasons we use in Australia HCs easely because it has a Mercaptan
smell similar to LPG and even that is smelled in extreme small quantaties.

http://www.frigopol.com/?var_lang=en&rq=proj

++++++++++++++++++++++++++++++++++++++++++++++++++++
An air conditioning system with R723 as refrigerants - an alternative to ammonia, but with better characteristics.

This air conditioning system is operated with a azeotropen mixture from 60% Massen% ammonia and 40% mass per cent of Dimethylether as refrigerant.

Apart from higher cooling capacities, better COP and better oil solubility smaller compression temperatures are obtained.
With the employment of R723 the condensation is possible with an air cooling, which replaces that complex to employment of a cooling tower.

Project description:

Non-artificial refrigerants, aircondition with two circuits.
2x 35L-DLYD-10

Technical Data
Qo=6,5 kW
to= +5°C
tc=+35°C

Refrigerant circuit1 R717
Refrigerant circuit2 R723







FRIGOPOL RHL - Kälteanlagen GmbH, Gamser Str. 21, A-8523 Frauental
Tel. +43 (0) 3462 70 000, Fax +43 (0) 3462 70 000-50, office@frigopol.com
[ top ] © e-dvertising.at [ back ]



Try this websire and read

jg/oz

Mark C
19-04-2004, 02:21 PM
Hi guys.... I am amazed at all the fear and disinformation found here. You are obviously posting things about which you have no experience or understanding.

http://www.coldprofessionals.com/_borders/conbtn21f.gif

First, Ammonia is widely and safely used throughout the world. It is commonly available everywhere, and other refrigerants are not. Couple this with the fact that there is ZERO of the so-called "Ozone depletion" factor, ammonia escapes and cleanses the air and is a fertilizer.

I would much rather be in a room full of ammonia gas, than one filled with a HCFC gas!

I am one of the 9% of the human population that gets heart palpatations when breathing other typical refrigerants such as 12, 22, etc. I would undoubtedly suffer a heart attack should I be exposed significant amounts. These other non-naturally-occuring molecules are never "good" for anything but heat transfer or oil removal. We won't even go into the cancer causing aspects of the non-ammonia refrigerant.

There is a complete misunderstanding of the nature of ammonia used as a refrigerant in this forum. First, you do NOT bleed from the mouth or nose after being exposed. The ammonia is absorbed into the mucous membranes and the body reacts to found the tissues with water. Pulmonary edema is the most likely event as the body attempts to dilute and process the irritant. If someone did bleed from the mouth it was the result of another injury.

Peter, the leak you describe happened because you did something for which you were not trained and you did it wrong. Ever hear of hydrostatic trapping? You also were a danger to yourselves and placed yourself in danger and got hurt. Unless you were sweating profusely from your fear in your recent service of ammonia systems, you would not have felt anything on your skin from what you describe you were venting. It was fear you were feeling.

Who cares if a small leak occurs through a packing when the valve is turned? It is part and parcel of the equipment design and is not a danger. Remember, ZERO environmental damage.

Ammonia is used by the power generation industry to clean stack emmissions from hydrocarbon burning facilities. If you have an ammonia leak, the government ought to reward you for clensing the air instead of fining you. Ammonia is a bouyant gas and rises quickly under most circumstances to disperse in the upper atmosphere. It does not hug the ground as the non-natural refrigerants do, thereby not causing wide-spread death and panic. (I complete the air modeling for my ammonia refrigeration clients.)

Ammonia is NOT a poison. It is not a carcinogenic material. It is an irritant. It is NOT toxic. The mechanism of damage is that of a chemical burn where the body will food the tissue with water to dilute. Yes, people can die from ammonia exposure, but it is extremely rare. The last person to die from it in the USA was a handicapped person living with emphasima (sp?) next to an ammonia refrigeration facility. (Where he should have never been.) He was unable to escape effectively and was overcome because of the lung disease.

I have been on the forefront of the service and installation of Ammonia refrigeration systems for over 25 years. I have been involved in many accidents, some fun, some serious, in my years. I have breathed many times what is regulated to be the "Immediately Dangerous to Life and Health" level of fumes with no long term effect and no scars.

Ammonia systems are not inherently dangerous, any more than anyother type of refrigerant is. Training and understanding and respect are the key. Disinformation and being scared are not. Ammonia will be used in more and more smaller systems as the codes are changed to reflect the technology and current design capabilities of systems designed as such. Get over the fear, and LEARN about this great method of refrigerating and you will know what a bunch mule marbles has been written about it and how wrong your views of it are.

Unless you are trapped in a closed room with ammonia, you are unlikely to be hurt, seriously or otherwise. I have had ammonia sprayed on me many times from mistakes made (mostly by others lesss trained than I). I have had liquid sprayed into my eyes and I have no long term effects because of my training and reactions. I have been sprayed with liquid and had my skin frozen to my shirt several times and I have no long term effects because of my training and reactions. I have had it sprayed on my bare skin, and I have no long term effects because of my training and reactions. I have breathed it on the job so many times it is not something I panic over, and I am more likely to go looking for the leak than run, and I have no long term effects because of my training and reactions. You guessed it, TRAINING and DISCIPLINE are the key to safely using it.

Ammonia is used for many things and truly much closer to people and by untrained ill-educated people. Billions of pounds are dumped into the ground all over the world as fertilizer by people every year. Many of these folks have no clue but to run if something goes wrong. We would hear of countless deaths in this regard if there was anything so dangerous used such as has been discussed incorrectly here!

There is no commonly used (Or legally useable) refrigerant that has a better actual COP in use, with the refrigeration design optimized equally for each refrigerant used, than ammonia. It's all about physics, and not marketing. (IE: You cannot use ammonia efficiently when comparing it to an air-cooled system.) Ammonia is the best from the standpoint of eco-friendly, ease of use and system additions, and efficiency. BAR NONE. Get anything else out of your mind.

Azeotropes using ammonia as one component is a crutch used by people who use inferior equipment from other refrigeration industries (commercial) because they do not understand how to handle the oil in a true industrial ammonia system. These systems are sub-standard and completely unneeded. I won't even go into my experience with bitzer and their attempt to sell compressors to the companies I have worked with. Bitzer does not (at least to my mind) make any compressor that I would consider using in a true, industrial ammonia refrigeration system. (Qualifier: I have not spoken with them in the last three years, and I may not know of their newest products.) I would say categorically that any equipment designed first for a CFC or an HCFC (or any other refrigerant) is not optimally useful for application with ammonia.

A water cooled condenser is NOT a complex piece of equipment! You cannot get any simpler than that!

We in ths USA are not "lucky". The OSHA and EPA regulations class us in the same category as poisonous chemicals where one or two molecules absorbed into the skin will kill. We take great pains to use and design ammonia systems safely. Education and training are the key to the safe use of this refrigerant. Virtually every system has detectors to start remote response to a leak in any form.

Ammonia refrigeration trained personnel are at the top of training and ability. They deserve to make better money. However, in the USA, ammonia systems are actually less expensive to install and to maintain. Elsewhere, welllll... have you ever tried to get 2000 pounds of R22 (back in the early 80s) in the middle of nowhere Kenya? Ammonia was readily available!

Anybody who thinks that oil must mix freely with the refrigerant may go directly to the back of the class for remedial training.

Anytime a company allows a system to deteriorate and fail, and does not train their people to use the tool properly to refrigerate, they are allowing this bad information to be reinforced, and your fear will be greater.

As long as you folks in this industry promulgate this fear and disinformation you are so content to parrot here, you will be missing one of the chances to utilize one of the best and safest refrigerants.

Andy
19-04-2004, 02:56 PM
Hi :)
and you thought I was ticked off at the lack of understanding of NH3 and it's safe application :D :D
Mark C :) there is one alternative for NH3 when applied in low temperature blast freezing and that is a CO2/NH3 cascade. Higher COP lower and if required a lower evaporation. But that is the exception. If fairness to bitzer their open screws actually perform better on Low Pressure Receiver NH3 systems than can be simulated in their software. (we use them for small loads, in dual or tri compressor pacs up to say 200kW at deep freeze conditions).
Kind Regards. Andy :)

Mark C
19-04-2004, 03:29 PM
Hi :)
and you thought I was ticked off at the lack of understanding of NH3 and it's safe application :D :D
Mark C :) there is one alternative for NH3 when applied in low temperature blast freezing and that is a CO2/NH3 cascade. Higher COP lower and if required a lower evaporation. But that is the exception. Kind Regards. Andy :)

That is not an apples to apples comparison. :cool:

Peter_1
19-04-2004, 05:01 PM
Hino experience or understanding.
No??? How you determine this on a distance of some thousands of miles.



I would much rather be in a room full of ammonia gas, than one filled with a HCFC gas!

Well, that's your decision. I wanna live some longer.


First, you do NOT bleed from the mouth or nose after being exposed.

Hey, you say I'm a lier. I know what I saw and I know he was at home for at least 2 months. These are facts.



Peter, the leak you describe happened because you did something for which you were not trained and you did it wrong. Ever hear of hydrostatic trapping? You also were a danger to yourselves and placed yourself in danger and got hurt. Unless you were sweating profusely from your fear in your recent service of ammonia systems, you would not have felt anything on your skin from what you describe you were venting. It was fear you were feeling.

Jesus, you make fast conclusions. Hydro trapping? No never heard of it, we use the Dutch expression for it. :D
Hydro tapping is only possible Mr ammonia if you can vent via a servicevalve to water. And if there is no service valve or the service valve is so rusty that you can't open it anymore. What then wise guy?

You don't know my history at all but make statements. You've become just like Bush.

Your statement about the fact that you don't feel ammonia on your skin, are you a carpenter or so?
I don' t have fear when working on it, I'm just very prudent. That's all.
I will post some pictures from a installation - some of the posters saw them already - we did and you will need to revise your opinion.
Well, why should I post them anyway. Perhaps you should learn from the pictures how you must hydrotrapping. :D


Remember, ZERO environmental damage.
And your lungs?



Ammonia systems are not inherently dangerous, any more than any other type of refrigerant is. Training and understanding and respect are the key.
The first reasonable quote.


...and I have no long term effects because of my training and reactions.
You THINK you haven't them, that's something else.


TRAINING and DISCIPLINE are the key to safely using it.
I bet a former Marine.


A water cooled condenser is NOT a complex piece of equipment! You cannot get any simpler than that!
I didn't said it was.


We in ths USA are not "lucky". The OSHA and EPA regulations class us in the same category as poisonous chemicals where one or two molecules absorbed into the skin will kill. We take great pains to use and design ammonia systems safely. Education and training are the key to the safe use of this refrigerant.

You think that regulations are elsewhere less strict then in Cowboyland??
Come on!!
Why Bush won't sign the Kyoto agreement or at least why won't he follow the proposed limitations?


Virtually every system has detectors to start remote response to a leak in any form.
Why you install them anyway? Because it's more danger IF something should happen.


Ammonia refrigeration trained personnel are at the top of training and
Waw, glad you say it from yourself. Makes it very believable. All we, the other ***** guys are de facto the stupid ones now.


They deserve to make better money. However, in the USA, ammonia systems are actually less expensive to install and to maintain.

I don't believe this.


Elsewhere, welllll... have you ever tried to get 2000 pounds of R22 (back in the early 80s) in the middle of nowhere Kenya? Ammonia was readily available!
Didn't met Marc over there. Lucky for you.


As long as you folks in this industry promulgate this fear and disinformation you are so content to parrot here, you will be missing one of the chances to utilize one of the best and safest refrigerants.

sure the best but safest???


PS: that logo, is that from sort of Hells Angels Bike club?

You can see - saw it on your (is it anyway yours?) website that you're in fact not long in business. And I mean as a self-employed one.
You're fallen high but you can fall quick much deeper and faster if you threat all your clients like this. Knowing yyour job and running a business is something completely different. It's not because you're a succesfull tech that you will be succesfull doing the same job but then self-employed. You need that little charisma and adapted attitude (which you are missing)

You have to polish your website a little bit because most of the links aren't working.

Mark C
19-04-2004, 10:17 PM
Peter, I was not speaking directly to you in all of my posting. However, it is painfully clear that you have a limited and somewhat fanciful experience when it comes to using or experiencing ammonia as a refrigerant. Fear of it seems to rule your focus.

I would know the ammonia is in the room and would leave. If I was in the room of HCFC gas, I would not know it... Until asphyxsia or a heart attck occurred. Ammonia is not poisonous or otherwise harmful if you get away from it. Nor is it carcinogenic.

If indeed you did see blood as you describe, you do not understand or know what actually happened. Exposure to ammonia inhalation does not cause blood from orifices. It causes pulmonary edema. You misinterpreted the cause of the blood. There had to be another cause. Period.

The fact that you have never heard of hydrostatic trapping proves you were not servicing correctly and speaks volumes towards your abilities. I teach refrigeration professionally, both in the private sector, and have taught at the college level. Maybe you should consider a little more education? Hydrostatic trapping of liquid is the trapping of liquid between two valves when servicing without vapor present. This causes pressures hundreds of times what the normal P-h diagram would indicate.

"What then wise guy"??? I don't really know, as I was not there, but I assure you I would have completed the work differently without getting a "snoot full".

Your hatred of our government leaders shows through. You seem to only wish to cling to, and foist upon us, these insults. It is a pity. You do not know me at all, but wish to use your political views to disparage me.

It is also a fact that you would not feel ammonia vapor on your skin under the circumstances you describe. I have no idea why or what, but ammonia vapor in that concentration is not going to be felt on your skin. You would have suffered pulmonary problems at this level.

I have no lung damage, and have been around ammonia in high concentrations for many years.

The condenser information was from another member in Australia. The fact that you think I said this about you is telling me that you do not read and understand well what is in this thread.

Actually, I was an officer in the US Army. What does that have to do with anything, except to attempt another disparaging comment?

"Cowboyland"??? ...another attempt to disparage me and my country, no doubt. Be an adult and think. I know not of your regulations you deal with in your country, but your assertion that we are not encumbered with such and react to them as such is a load of mule marbles. Grow up! We are professionals here as well.

Bush will not sign the Kyoto Agreement because it is based upon pseudo-science and conjecture. It is bad for the USA and is not fairly applied to all. For your information, we are under tighter control in many facets than the Kyoto Agreement demands. ANyway, that's a dead issue, and good for it!

I cannot figure out what your objection to my statement of the fact that we employ ammonia detectors in our facilities? This is a rational design requirement to provide the safest system possible to protect life, property and limb.

I never disparaged the ***** guys. That is you. I only said that good ammonia refrigeration tech are at the top of the training and ability "heap". The level of required training is much higher in the USA than for a "*****" residential or commercial technician. A good ammonia tech can virtually be working anywhere, at a higher than average wage. Simple facts.

I care not a whit about what you believe or theorize. I'm stating that an ammonia system for an industrial application such as a winery, cold storage, hog or beef kill facility, etc..... ammonia is a less expensive system to install and maintain. In the USA, anyway.

non-sequitur.... Ammonia is available anywhere in the world. Odd CFC, HCFC, and other refrigerants are not. (Certainly not the odd azeotropes and patented ones.) I guess you have no experience in this?

There have been more deaths in the USA due to non-ammonia refrigerants than there have been caused by ammonia refrigerants. That is fact.

That "logo" you describe is a patch I sell and give to my clients. It is used to identify in an eye-catching way the persons who are trained at a higher level to respond to an ammonia incident. It is a team builder id for use on the uniform and jackets. It is well thought of and I have hundreds of requests for them monthly. (Much better than a pen to give a client too.)

Again you attempt to disparage me and my experience. I have been an owner, Chief Engineer or Senior Engineer of several ammonia refrigeration contracting and enginnering firms and businesses over the years, not just my current one. (I started as a stock boy and welder's helper.) I have served at the national level for our professional organizations. I am known, and a recognized leader in our industry here in the USA. You are clueless as to my business. (Yes, my website does need a refresh, however, it does not really pay the bills directly, and I am much too busy to do so right now.)

You find me abrasive, largely because of your hatred of all that is "cowboy". I pull no punches and speak plainly and truthfully. I owe you nothing but my knowledge and experience to help the industry better itself and possibly help an ammonia techinician to not hurt himself or others and to work safely.

In short, yes, when used properly, there is no better, nor safer, refrigerant to use than ammonia!

shogun7
20-04-2004, 01:12 AM
Now Adolf, there you go again picking on America's Hero
Don't forget Blair is in bed with him, or do you dislike daddy also and who's WE is that all of you :D
OH, and Mark watch out for the idiot previous to my post

Mark C
20-04-2004, 01:51 AM
Perhaps because of Bush and his profoundly well demonstrated "Texan Idiot" characteristics we have all become a little prejudiced in our views of Americans.
:)

Funny, My family has known the Bush family through business contact for years. It's really odd how you "Eurocentric Bush bashers" ... nee "Haters".... have swallowed that press-induced "Dumb Bush" thing hook, line, and sinker. Really, I thought you folks were brighter than that! I teach my kids to examine what they are told and not just believe everything.... :eek: (Psst.... Bush ain't really a "Texan".)

Gee, I'll even bet you think that President Ford was a bumbling pratfall waiting to happen, or that Dan Quayle was stupid too!?? EH? :rolleyes: If you would take the time to examine first hand, instead of parroting the same old political clap-trap, I might believe you were anything more than a.... well, I digress. :D

shogun7
20-04-2004, 02:15 AM
HIP HIP Hurrah, HIP HIP Hurrah, Well said Dear Yank!! :D

baker
20-04-2004, 03:31 AM
Gosh, a little confrontation happening here. Nice one :)

Perhaps because of Bush and his profoundly well demonstrated "Texan Idiot" characteristics we have all become a little prejudiced in our views of Americans.

You know, it's funny, we don't blame zimbabweans for Mugabe and we don't blam Iraqi's for Sadam but we blame the Germans for Hitler and the Americans for Bush... funny world :)

This got me thinking. Consider Hilter. To successfully fight him, we had to believe that all 50 million germans were nazi goons, baby bayoneting hun. The fact that most were peace loving normal people tricked into war was ignored. The fact that Hilter dressed SS troops in Polish uniforms and "invaded" Germany on Sep 1, 1939, starting WW2 shows how he had to manipulate his population.

In these politically correct times, you cannot use the "nigger" word unless you are black. You can't criticise Israel unless you are jewish, and you can't point out Bush's lies and deceits without being considered anti-american. This is a pity, since many people confuse the issues and take offense when none was meant.

I have been accused of racism because I think that changing the name of Bombay is stupid. This doesn't bother me, but the accuser now sees more "racist enemies" surrounding him.

We need less anger in the world. Unfortunately, some influential people see it to their advantage to encourage this.

Mark C
20-04-2004, 03:39 AM
....and you can't point out Bush's lies and deceits....

If you can prove any of this, the world wants to know!!! Please do tell, and let's not just parrot that crap you hear on the news that is unsubstantiated and wishful thinking on the part of those opposed.

Mark C
20-04-2004, 12:36 PM
However, observing the American way of thinking has become quite a horror show. In these parts Americans used to be referred to as merely loud clumbsy thinking people, now they're referred to as stupid people. It's "stupid americans" these days, not "americans" anymore and the locals in these parts don't even realise they're saying it...lol.

Not even poor old push, he's trapped himself into that "Texan Idiot" roll for the rest of his life. Listen to his explainations, despite failing misserably at everything he's tried to do, he always has to explain that, despite reality, "he still believes in his heart that he's doing the right thing"... But to people in these parts it's no mystery why he is only ever thinking with his heart. :)

Actually, Marc....

In these parts, Europeans for the most part, including most of Britain, are viewed as being the same old appeasing boobs, completely unable to do anything that needs done. More and more shrill words to condemn, yet nothing is actually accomplished! ....Especially if it is not in their backyard. Where is Winston when your country needs him? OH, Tony Blair stands up to be counted! Europe is business as usual. Appeasement, and inaction. Where did it get you before?

I do listen to what Bush says; He speaks plainly and from the heart. I wonder if, Marc, you actually watched the entirety of what Bush says, or just the edited sound bites the press wishes to show to massage your views? Your press, it is my conclusion, manipulates your opinion through what they choose to show, and most Europeans, and Britons, do not get the entire truth. Like I said, don't live an unexamained life; Why don't you think for yourself?

Once again, this forum, despite being a "Refrigeration" forum, is jaded by the blinders of your politics. Your views come out, I can only assume, to disparage me. Let's get back to the subject!

Mark C
20-04-2004, 04:35 PM
hi andy,

dont ammonia attacks aluminium?

chemi

Yes, and no. Certain Aluminum Alloys are more prone to corrosion than others, but mostly it is a function of the fabrication properties of that alloy which determines what one is used. Aluminum tubes are frequently used for Ammonia systems. Care must be taken of course to use dielectric couplings where transitioning to a steel piping system.

Peter_1
20-04-2004, 06:15 PM
More and more shrill words to condemn, yet nothing is actually accomplished! ....

What has the US lost in Afghanistan? Only the fact that you need the country to install a huge oil -pipeline from Turkmenistan to Pakistan. The other route was via Russia which they didn't of course not preferred.

Don't forget also that they created there Bin Laden, they funded him with billions of dollars. Or was this not in your news?

What have they lost in Iraq now? Mass destructions weapons? The troupes didn't found any Gas weapons? Nuclear weapons? Zero decimal zero?
The only thing they wanted was a complete control of the oil.
The reasons why they attacked Iraq were seen afterwards all been false.

That's what Richard Clarke, anti-terror expert since 30 years 'Against all enemies' also said 2 weeks ago in his new book (was it in your bookstores or Bush bought them all at once?)
The whole state was shaking man.
Clarke know his job I think, otherwise they shouldn't let him there for so many yeras.

Exact same story for Kuwait? Such a small country. Why didn't they interfered in Rwanda where hundred thousands were killed, why they didn' t helped in the Sahel... One simple answer.

What have they lost in Israel?


I wonder if, Marc, you actually watched the entirety of what Bush says, or just the edited sound bites the press wishes to show to massage your views?
The speeches he gives is what other has written for him. Those who fund him, he's only a puppet on a string and has to do what his fund raisers advise him (if he wants to be elected in June)


Your press, it is my conclusion, manipulates your opinion through what they choose to show, and most Europeans, and Britons, do not get the entire truth. Like I said, don't live an unexamined life

It's the world upside down, you don't have a clue what we ares seeing here and what they tell us here. That's clear now.

It's your media which is so hypocrite. They beep the words f**k and s**t and some other obscene ( are they anyway?) out in every ting on the television but on the same time when they say f**k, they shoot somebody or put a knife in someone's stomach, completely unsecured and if they let show a breast, they fade it out. (what a pity) What's the logic in this.
What will frighten a kid more? Do you think kid never saw a breast before? It was the first he saw when he was born.

We dare to say for what we stand for, even if it's not the opinion of the US. And sometimes with great consequences. Look what happened with the Iraq crisis in Belgium. Belgium refused to cooperate without a UN resolution which was fair.
And that's why they have installed the UN: to prevent peoples like Bush doing stupid things in the world. Beut he was so egocentric when he said "well, i will attack, even without a UN approval"
He thinks he is God himself.

What was Bush' reaction to this: we will move the NATO headquarters in Brussels. Bush forgot that NATO not stands for US, he thinks that this building is a US building.

Thats the reaction of a child. I you don't do what I' saying, then I will take your candy.

I didn't turned my head when Janet Jackson showed her breast. And in the US it was big news, it even overwhelmed the Iraq news.

Mark C
20-04-2004, 07:02 PM
What has the US lost in Afghanistan? ....

Hey Peter, you Euro-boob. Get back to the topic at hand... Refrigerants, specifically in this thread ammonia. I tire of your diatribe of stupidity and blathering.

Mark C
20-04-2004, 08:57 PM
Hey, Peter, did I tell you what they call Americans around here these days? Lol, seems I did :)

Oh, Marc?? If you cannot keep topics "on topic", in a professional refrigeration fourm, and cannot resist delving into that trashing of members and participating in such.... Well, you are not much of a "Moderator".

Andy
20-04-2004, 09:13 PM
Hi :)
we Irish are slowly learning to keep our politics to ourselves, it has been a painfull slow lesson played with peoples lives :(
I suggest you guys keep your politics to yourselves, for fear you end up like we did in the North of Ireland :(

On a lighter note why do we even bother using ***** :D Ahh now I remember so we can charge the customer for endless hours leak testing :D :D

Kind Regards. Andy. :)

Mark C
20-04-2004, 09:17 PM
"....On a lighter note why do we even bother using ***** :D

Hold that thought!! I like that idea.... http://www.mboxcommunity.com/images/Jester.gif

baker
21-04-2004, 03:53 AM
I wonder how much of ammonia's success is due to it not being miscible with oil. Lack of oil in the evaporator must surely make it more efficient.

It has been reported that R410A is inferior to R22 theoretically (thermodynamic calculations) but better in practice. With oilless compressors now becoming available, it will be interesting to see if they are ever used with NH3.

jg/oz
22-04-2004, 01:50 AM
Friends,
if this is the way we are going to correspond to each other than I am
out of this conversation. I think we have an ethical Code of Conduct
to behave on this Forum
jg/oz

RogGoetsch
22-04-2004, 07:06 AM
In scientific circles, there is a testing procedure known as "double-blind testing" in which neither the test subjects nor the professionally-trained observer knows which subject received the real drug and which received an inert compound.

It has been discovered that this procedure is essential because even a professionally-trained observer trying only to be unbiased is unable to do so if he knows which drug is real. His beliefs about the test affect his observations.

Since our biases affect our very observations themselves, how can we possibly hope to know the truth if we can only perceive what we already believe to be true? We can't. We tend to accept evidence that supports our beliefs and discount evidence that does not.

Moreover we identify with our beliefs and feel that anyone attacking those is attacking us personally.

The scientist recognizes that everything rests on assumptions, fallible observations and fallible processes. So to think rationally means we must doubt our own conclusions and seek the errors in our own thinking all the time.

The opposite of this is certainty. This is the hallmark of those who have closed their minds. If you are certain you are right, you are not operating in the domain of rational thought but in that of emotional "rationalizing" thought. This is natural because our experience is more powerful than our thinking. If you experience a feeling, the rationalizing brain has the relatively simple task of rationalizing the feeling rather than reasoning towards the truth. Evidence which contradicts the feeling can be ignored since it is obviously in error.

So the first clue that you are not really thinking is that you have a strong feeling about the subject. The second clue is that you are convinced you are right. The third clue is that your thinking is simplified: you think in categories (liberal vs conservatives, evil vs. good), generalizations (those people are all jerks, inferior), and other simplifications. The fourth clue is that you don't refute ideas, you attack the holder of the idea (ad hominem attacks).

My own technique for trying to approach the truth is to assume that human nature is pretty much the same everywhere. Self interest tends to bias perception for everyone about the same. I think most people are sincere in believing what they are about is in the best interests of humanity.

The men who piloted the airliners into the World Trade Center believed they were doing God's work and striking a blow against Satan. The men who called for a bunker-busting bomb to be dropped on a residential Baghdad neighborhood because they thought Sadaam was there believed they were waging a war against "evildoers" and the loss of innocent lives would prevent larger losses later.

I suspect what we are seeing is a stage in the evolution of humankind. We have evolved to a point where we are altering our entire environment by using our rational minds, but we have not yet learned to act rationally. Will we make it?

Rog

Andy
22-04-2004, 08:13 AM
jg/oz :)
don,t take these guys seriously, they are all piss and wind :D I don't think any of them are entirely serious about the political ideals they are coming out with.
I know for a fact that Marc is taking part in a little known past time called Yank bating, which to date has been quite sucessful. :D
I fear our friends accross the Atlantic take critisim from europeans much too much to heart. If the same debate was to go on between two europeans, the needling would not be taking anyway near as seriously. ;)
Kind Regards. Andy :)

Mark C
22-04-2004, 11:47 AM
Says who?

Says, me, you twit. "Pouncing" ... "tearing apart"??? Get a life and get real. You came to a battle of wits unarmed. You are not much of a moderator in a professional forum in which you take part in this O/T baiting game. You are a "Euro-boob" yourself.

GET BACK ON TOPIC, or go elsewhere. This is the absolute last time I will respond to anything you ever say that is not refrigeration related. You are a failure.... GOODBYE!

Mark C
22-04-2004, 12:06 PM
I wonder how much of ammonia's success is due to it not being miscible with oil. Lack of oil in the evaporator must surely make it more efficient.

It has been reported that R410A is inferior to R22 theoretically (thermodynamic calculations) but better in practice. With oilless compressors now becoming available, it will be interesting to see if they are ever used with NH3.

Oil management is indeed quite different with ammonia. It does require a different mindset. I sure would not say that there is a complete lack of oil in the evaporators and throughout the system! The immisicibility of oil in ammonia is one of its attributes!

It is quite possible to completely log an avaporator with oil, and, like all oil in a refrigeration system, it acts like an insulator. It is not an uncommon experience for me to have shown up on a service call that a room will not cool to find an oil-logged evap! Usually, this is at a time when the hot gas has not kept pressure high enough to blow the oil through on defrost. (As in winter or other low ambient conditions) Sometimes, it is just an accident of piping or valving (disrepair) that allows this to happen.

Make no mistake, oil needs to be managed in the ammonia system.... It needs to be recognized that it settles in and needs to be removed!! :D I have one client who lets it accumulate for the entire grape cooling season in California. When all the grapes are shipped after that season, it is their time to drain oil.... hundreds of gallons of it! Per coil. Mind you, these are huge pressure cooling systems that have huge coils in a bunker-coil setup.

I have not played with the newer replacement "*****s" to have any opinion on them. However, I do not believe that any design consideration will call for the ammonia industry to attempt the use of "oil free" compressors. It just is not a big deal to go drain oil once in a while!

Mark C
22-04-2004, 12:16 PM
In scientific circles, there is a testing procedure....

Rog

<<<Scratching head>>> Ever the diplomat, Roger! (All while holding a club that the other fails to notice.) You never change, and I like that! :D Rog and I went to the same school, and have worked at the same company.... we go "way back".

WebRam
22-04-2004, 12:22 PM
Gentlemen.

I do believe you have went "off Topic"

Please return to topic, thanks

chemi-cool
22-04-2004, 02:59 PM
hi mark,

dont you use oil separators in ammonia based systems?

chemi :confused:

Mark C
22-04-2004, 03:39 PM
hi mark,

dont you use oil separators in ammonia based systems?

chemi :confused:

Yes, chemi... These are typically coalescing filter elements that are installed post compression. (It is rare today to use a central vessel to do this.) However, these are not 100% effective, and They pass about .05% of the oil anyway if they are in good condition. So the oil circulates freely in the system and winds up in the low spots, which are typically at the bottom of liquid recircualtors, and Oil distallation Pots are used to remove it from the system.

chemi-cool
22-04-2004, 04:24 PM
hi mark,

the reason I asked is that some years ago I was asked to look at a condensing unit ( a miniture in your respect) 20 HP that was feading 100% fresh air 25 meters below and the oil presure controls triped every week.
the tech that was looking after it said he had added some 40L per month!!!!!
of oil.

there was no oil separator used!! strange design.

left them an offer to fix the unit and after two weeks they called back- now it is not cooling either!

what I did was recover all the gas, install an oil separator and.... at the bottom of the evaporator brazed 3/8 tube and an SV controlled by compressor's contactor that opened for 30 sec 5 min. after unit came on.

the end of this tube went int the suction line just before the condensing unit.

because of the presure dif. it pushed the oil that left inside the evaporator up.

after recovering the system, 45L of oil came out!

chemi

Mark C
22-04-2004, 04:29 PM
I'll bet!! Yikes!

chemi-cool
22-04-2004, 04:34 PM
so why not use it in ammonia systems?


chemi

Mark C
22-04-2004, 04:42 PM
so why not use it in ammonia systems?


chemi

I guess the best response would be that it just doesn't matter all that much. The oil in an ammonia system gets trapped mostly in the oil coalescing filters at the compressor oil seperator. The small amount that gets by that gets trapped in the oil distallation pots. The small amount that gets past both of those generally gets blown about until it settles back into the oil pots.... We simply drain it when it is there.

Only on the oldest of systems where there is no coalescing oil filter at the oil seperators do we see quite a bit of oil to be distilled. It's just a part of the normal "things to do".

Andy
22-04-2004, 05:07 PM
Hi chemi :)
on our low pressure receiver systems, we would automatically drain the oil from the receiver, PAO oil is used in these systems. Doesn't really matter about a little carry over as it all makes it way back to the LPR and is rectified.
Mark/Chemi :)
before you ask an LPR system is a liquid over feed system, with usually one or two coolers on it. Liquid is fed into the evaporators by an expansion device, much like DX, the liquid comes out the cooler suction line and is trapped in the LPR and boiled off by indirect heat exchange using the haet available from the liquid off the condenser, subcooling the liquid in the process.
Nominal capacities are 100 to 400kW at -30 C evaporation.
Kind Regards. Andy :)

Mark C
22-04-2004, 07:30 PM
Lol, what's there to arm myself for?

Back to the subject at hand.

Mark C
22-04-2004, 07:40 PM
Hi chemi :)
on our low pressure receiver systems, we would automatically drain the oil from the receiver, PAO oil is used in these systems. Doesn't really matter about a little carry over as it all makes it way back to the LPR and is rectified.
Mark/Chemi :)
before you ask an LPR system is a liquid over feed system, with usually one or two coolers on it. Liquid is fed into the evaporators by an expansion device, much like DX, the liquid comes out the cooler suction line and is trapped in the LPR and boiled off by indirect heat exchange using the haet available from the liquid off the condenser, subcooling the liquid in the process.
Nominal capacities are 100 to 400kW at -30 C evaporation.
Kind Regards. Andy :)

Ummmmm, not really.... I'm well aware of the nomenclature of the ammonia system. However, these systems sometimes have sixty or more evaporators, ice makers and other heat exchangers on them. I would not limit them to "one or two coolers on it." I have designed, installed, and operated systems with 9,800 connected BHP operating at multiple temperature levels down to minus 60°F.

Liquid is fed to the evaporators through a hand expansion valve which is actually used as a balancing valve. The actual expansion to low temperature happens within the recirculator vessel, and not at the evaporator.

when heat is added at the evaporator, the liquid present then flashes to vapor, absorbing the heat. There is no DX evaporation, and certain not any superheat generated. There is no TXV or superheat to be "set" here, and two to five times the vapor weight (depending on temperatures and the needs of the circuiting) is returned to the recirculator vessel via gravity after exiting the evaporator and riser.

The returned liquid is then pumped out or "recirculated" to the evaporators again. The oil, usually heavier than the refrigerant liquid is traped in the recirculator vessel. What small amount does get out to the evaporators is returned with the liquid ammonia returning from the evaporators after a high load "blows it through the coil" or the coil is defrosted, and drained of all liquid.

Oh, and there is nothing "unreliable at best" regarding a properly designed and circuited ammonia refigeration system. As a matter of fact, there is nothing more reliable or efficient! Anybody that uses a TXV on an ammonia system really does not understand the proper design and use of an ammonia system. TXV should rarely be employed on an ammonia system.

Andy
22-04-2004, 09:53 PM
Hi Mark :)
LPR systems may have only a few coolers on them, but they are not DX in nature but liquid overfeed. Charges are critical, and thus an LPR system allows Nh3 to be used where it would normally not be aceptable.
Pumped Nh3 has it's place, but that would not be on the roof of a building in London. LPR chillers are now quite common on government building in London.
The only DX Nh3 we use is for economisers on plate and shell heat exchangers :)
Kind Regards. Andy :)

Andy
22-04-2004, 10:01 PM
Andy, surely the most widely seen application of ammonia is in the form of liquid overfeed, LPR or PLA, because overfeed assists oil return
I would say so. I did see a good aplication of DX Nh3 once. A compound compressor plant had an extra high stage compressor, to handle the a high temp side load at intermediate pressure. The rooms requiring high temp cooling were fed H.P liquid by DX valves and the subsequent dry return was fed into the interstage closed flash intercooler. :D
But that is the only one in 15 years ;)
So DX Nh3 is not common.
Kind Regards. Andy.

Andy
22-04-2004, 10:21 PM
Hi Mark :)
yep a loading bay also. Neat solution where only a small to medium sized HT load is required.
Kind Regards. Andy :)

shogun7
22-04-2004, 11:45 PM
When I joined this forum It was with the express purpose of trying to help others in our industry with my 40+ years of experience, but it didn't take long to get bashed buy adolf and a few others with your chicken **** politics. Some of you have a real problem understanding us "Colonials" .

Admin note
this poster goes on to express his opinion in a rather forceful way.

WebRam
23-04-2004, 12:07 AM
OK, I gave you all a chance to get back to the subject.