ammonia and humidity

[gui.furlan]

Hi guys,
I want to know what problems can i have if my instalation have alot of water in the amonia system.
Than you all

[Iceman717]

Hi,

If your charge is starting to get aqueous you'll find you need to pull lower suction pressures to get the same refrigeration effect. There is also the chance of freezing up expansion valves.

[NH3LVR]

It depends on what you mean by a lot of water.
I once had a oil cooler splt on a medium temp installation with Vilter compressors. We had enough water in it that we had to do repeated oil changes on five compressors.
We never went down but kept draining oil from the vessels until we got out as much as we could.
That being said it is never a good thing, but it is not uncommon to have some water in an NH3 system. It is almost impossible to avoid over time if you run into a vacuum.
Equipment is avaiable to remove water if you wish to install it.
If you have a two stage system the water tends to collect in the intercooler where you can easily drain it.
You can remove a great of water (not all) over time if you have a oil pot that you can valve off and pump out.

[Tycho]

regulating valve freezes over, acid in compressor oil, etc etc

[gwapa]

In a soft drink instillation working at Te=-2ºC ,Flooded cooler. I found the the oil + ammonia + water form a kind of paste that damaged the compressor (Vilter Recip).
Normally a very low percentage of water is good to avoid corrosion in the carbon steal but to much is very dangerus and you loose eficiency
chears
Gwapa

[diego palma]

The contamination of water can occur in a facility since the period of
installation and assembly even during normal operation of the system.
Contamination during assembly:
• Condensation (moisture) inside the pipe during unprotected
assembly;
• Equipment, piping and other components exposed to the weather during
the assembly period without protection or without internal pressurization (with
Nitrogen, for example);
• Pressure vessels after hydrostatic testing cos that were poorly drained;
• Condensation (moisture) due to test co pneumatic air lines uti lizando
moist;
• Vacuum poorly done (or not done);
• Initial charge Ammonia the presence of water (from suppliers not
qualifi ed). Should be required certi fi cate of the purity (99.95%) Load of Ammonia
being supplied.
Contamination during the operation:
• Break-tube exchangers "Shell-and-Tube", mainly in coolers
water or condenser water;
• Procedures not suitable oil drain or vent Ammonia
Potted during maintenance or rows, with pressure below atmospheric
(Tev <-33.5oC). The risk increases when the purging is done for water tanks
and in this case it is recommended to install check valves on the line
purge to prevent the counter-fl ow water to penetrate inside the circuit
cooling;
24
Small leaks in valves, • gaskets, seals for pumps, compressor seals
and serpenti the evaporator when operating at low pressures (with
Tev <-33.5oC), or even gathering operation;
• Procedure vacuum unsuitable after maintenance of equipment
system. Often it is not done the vacuum;
• Ammonia uti Lizada for replacement with presence of water (from
suppliers unskilled markets).
However, it is not always possible to prevent water penetration into the system. Beyond
care with drainage and with the vacuum fi ca dif ficult to evaluate the contamination along
the years but the analysis of samples at various points in the installation.
One way to observe how much water penetrates into systems with low
pressures which have air vents is by monitoring the air vent. It
Importantly, the air that eventually enters the refrigerant circuit
Have moisture, but the air is vented which is completely dry since water is solubilizes
with Ammonia and fi ca accumulated in the system. When considering a period of 10 years
is not surprising to find 5-10% of water in the system.
A survey in the 90 [3] in more than 100 facilities in Denmark,
Norway and Sweden, has shown that most of them continue containing about 2% to 6% water
and more than 10% of the plants had more than 8% of water on
liquid separator at low pressure side.

[Nh34life]

As with NH3LVR, there is water then there is water! 10559
believe it or not that is an Ammonia sample, from a system that took on almost 60% of the charge in sea water the damage was horrendous and cost millions. the system is now back and running 2 years on and hasnt skipped a beat since the last oil change 1000 hrs ago.

[passandscore]

60%!!! How did so much water get in the system?

[Josip]

Hi, gui.furlan :)


Hi guys,
I want to know what problems can i have if my instalation have alot of water in the amonia system.
Than you all

Like said above you can have a lot of problems, but it is better to read all about by yourself;)

what you need ...refrigeration grade ammonia ...
http://www.tannerind.com/anh-specifications.html


ammonia properties ....
https://www.osha.gov/SLTC/etools/ammonia_refrigeration/ammonia/


about contaminated refrigerant ... ammonia in this case ...
http://www.airgasspecialtyproducts.com/products/anhydrousAmmonia/industrialRefrigeration.aspx

Hope this will give you some useful information ...

Best regards, Josip :)

[Grizzly]

If it is sea water that contaminated the system, I would guess a water cooled condenser?

The rest is pure physics.
Grizzly.

[Nh34life]

It was caused by a Static coil fracture on a Tuna well, the chief engineer took off as soon as the boat docked all three compressors died less than a week later.

[Vish]

Hi Josip,

I have seen the link that you provided for the quality of ammonia and would like to thank you for sharing this information.

However I am facing an issue these days with one screw compressor. The system was running fine until the previous week-end where we purged oil from the evaporator and added some ammonia. since then the system is behaving very bad and is creating havoc. We are having High suction pressure on the compressor (screw) and the oil is also getting the tendency to get carried over.

I am strongly believing that the ammonia is not the right quality but until now the supplier is claiming that the batch is OK and he is even arranging COA for me.

I would like to know :
1. Is there a standard for the cylinders of Ammonia Anhydrous refrigeration grade, in terms of colour/Size etc?
2. When I recieve the cylinders on what test can be done to know that it is really the grade for R717? We are trying to do a Pressure/Temperature Mesurement on the cylinder, but is there a kit or another means to measure this purity/water content?
3. If I got it right, if there is high moisture content in the ammonia, the oil would have a tendency to get Acidic. Am I right in this statement? Testing the acidity of the oil, as compared to another compressor which has not had this new batch of ammonia could give me an indication of the moisture content of this new ammonia batch?

Basically I want to rule out the ammonia quality first before I open the compressor.

If anyone has some information, grateful if you could share it.

Thanks,
Vish

[Josip]

Hi, Vish :)

welcome to RE forums ....



Hi Josip,

I have seen the link that you provided for the quality of ammonia and would like to thank you for sharing this information.

However I am facing an issue these days with one screw compressor. The system was running fine until the previous week-end where we purged oil from the evaporator and added some ammonia. since then the system is behaving very bad and is creating havoc. We are having High suction pressure on the compressor (screw) and the oil is also getting the tendency to get carried over.

I am strongly believing that the ammonia is not the right quality but until now the supplier is claiming that the batch is OK and he is even arranging COA for me.

I would like to know :
1. Is there a standard for the cylinders of Ammonia Anhydrous refrigeration grade, in terms of colour/Size etc?

yes there are some standards, not unified ... but the best is to check by yourself ....

http://www.psych.usyd.edu.au/whs/COP/BOC_Guidelines_for_Gas_Cylinder_Safety.pdf
http://gkrss.ru/services_en/fillingthecylinders.html
http://www.transcaer.com/docs/AATour/Transcaer_Ammonia_Training_Student_Handout_rev04.pdf
http://www.tannerind.com/PDF/blue-anhy-amm.pdf




2. When I recieve the cylinders on what test can be done to know that it is really the grade for R717? We are trying to do a Pressure/Temperature Mesurement on the cylinder, but is there a kit or another means to measure this purity/water content?

... not sure about kit, but there are small (1 or 2 lit cylinder) to take a sample and send it to lab ... not sure what is available in your country ....

Pressure/Temp mesurement ... the best is to put your cylinder with ammonia into cold room with known temperature and then the very next day you can check the pressure ... but you need precise thermometer and gauge ... it is simple but will not tell you too much ...




3. If I got it right, if there is high moisture content in the ammonia, the oil would have a tendency to get Acidic. Am I right in this statement? Testing the acidity of the oil, as compared to another compressor which has not had this new batch of ammonia could give me an indication of the moisture content of this new ammonia batch?

Basically I want to rule out the ammonia quality first before I open the compressor.

If anyone has some information, grateful if you could share it.

Thanks,
Vish

there are available kits to check oil .... but again you need to send a sample to lab .... like this one ....
https://www.refparts.york.com/ALLParts/WebPages/Refguard/OilChoice.aspx


Not sure what kind is your plant, but it is possible to install air purger and water purger unit to avoid future problems ...

http://www.hantech.com/products/pages/ap.htm
http://www.hantech.com/library/pdfs/WaterInAmmoniaSys.pdf
http://www.hantech.com/documents/PDF/APP001.pdf


also you can search RE archive to find some more info all about refrigeration and other things
... http://www.refrigeration-engineer.com/forums/archive/index.php


Hope this is of some help to you.


Best regards, Josip :)

[Vish]

Thanks Josip,

Will go throught the information that you provided and get back to you if in need.

Regs,

[RANGER1]

Hi Josip,

I have seen the link that you provided for the quality of ammonia and would like to thank you for sharing this information.

However I am facing an issue these days with one screw compressor. The system was running fine until the previous week-end where we purged oil from the evaporator and added some ammonia. since then the system is behaving very bad and is creating havoc. We are having High suction pressure on the compressor (screw) and the oil is also getting the tendency to get carried over.


I am strongly believing that the ammonia is not the right quality but until now the supplier is claiming that the batch is OK and he is even arranging COA for me.

I would like to know :
1. Is there a standard for the cylinders of Ammonia Anhydrous refrigeration grade, in terms of colour/Size etc?
2. When I recieve the cylinders on what test can be done to know that it is really the grade for R717? We are trying to do a Pressure/Temperature Mesurement on the cylinder, but is there a kit or another means to measure this purity/water content?
3. If I got it right, if there is high moisture content in the ammonia, the oil would have a tendency to get Acidic. Am I right in this statement? Testing the acidity of the oil, as compared to another compressor which has not had this new batch of ammonia could give me an indication of the moisture content of this new ammonia batch?

Basically I want to rule out the ammonia quality first before I open the compressor.

If anyone has some information, grateful if you could share it.

Thanks,
Vish



Vish, can you clarify if this screw compressor in question has a high suction or discharge pressure.
If its high suction pressure, is machine fully loaded would be the obvious thing to check first.

If you can detail what is doing pressures etc as just adding ammonia even with water in it cannot be the only possible problem.

How much did you add & where did you add it?

Sometimes a lot of things happen by coincidence & it can throw you off.