7 replies to this topic

[J_Leo]

Hi Folks,

 

We have closed loop glycol cooling water inside the air compressor packages by Atlas Copco. What kind of monitoring is good enough and at what frequency?

 

I need your advice on this.

 

Thanks,

Leo

[Art Montemayor]

I presume the following to be your case:

• The compressor is a 2- stage, reciprocating type with an intercooler and a final discharge aftercooler.
• Both the coolers as well as the compressor's cylinder jackets require a flow of glycol+water for cooling.
• The glycol+water solution is circulated to an external chiller unit that cools the solution and subsequently pumps it to various users, one of which is the air compressor unit.

The above is the normal, usual case where chilled, glycol+water is employed in a process or industrial plant.

I've used this cooling system in some of the plants I operated and I monitored the cooling requirement by the compressor with only three dial thermometers: one on the supply cool solution entering the compressor skid and another on the solution outlet on the intercooler and discharge cooler.  I never worried about the cylinder jackets.  You have little or nothing to worry about regarding the compressor's heat load.  The compressed air is not fouling.  The glycol solution is also supposed to be clean and non-fouling.

 

Your main concern is making sure that the solution's glycol content is kept up, that the refrigeration unit is working correctly on the chiller, and that the solution pump flow rate is what it is supposed to be to ensure you have adequate cooling at each consumption station.  If the chiller unit and its pump is working correctly 24-7, you should have no monitoring cooling worries on the air compressor package.

[breizh]

Hi,

You should drop an email to Atlas Copco for support .My experience with this technology and particular brand is about patrolling every shift and check the parameters /alarms on display at site .

A link is added for others to better understand the query :

https://www.atlascop...-and-air-cooled

Quality of water is key .

Note : Probably good to have people checking your cooling water system to take a look at this particular equipment  during their periodic visit . Let say once a month.

I'm more familiar with cooling water used to cool the system ( attachment).

 

hope this is helping you.

Breizh 

[Bobby Strain]

J_Leo,

    You might want to indicate what you are interested in monitoring. You may have intended to seek information on the fluid quality and lab analysis. But I am no mind reader.

 

Bobby

[J_Leo]

Art,

 

Thank you for your expertise. We have the system as you described. The model is ZR750. The operators have been monitoring the major operating parameters. The water quality issue was brought up during a HAZOP. 

you said that "The glycol solution is also supposed to be clean and non-fouling." Is this because there is corrosion inhibitor added?

 

Regards,

Leo

Edited by J_Leo, 20 March 2022 - 09:58 PM.

[J_Leo]

Breizh/Bobby,

 

In the operation manual provided, the cooling water quality must meet certain minimum requirements. Ryznar Stability Index (RSI) is used to indicate inspection frequency. If it is too high or too low, water shouldn't be used. Between certain range, corrosion inhibitor is recommended. However, no clear inspection frequency is defined.

Next step, we are going to collect samples to measure some parameters needed to calculate the RSI index. Parameters include, pH, TDS, hardness, M-alkalinity.

Glycol is not mentioned in the manual though.

I plan to talk to Atlas Copco for more details.

 

Thank you,

Regards,

Leo

[breizh]

Hi,

You should also talk to the guy in charge of water treatment for your facility  (chemical supplier) .

Another index to consider is Langelier index .

A good resource for water treatment attached 

Handbook of Industrial Water Treatment | SUEZ (suezwatertechnologies.com)

note : Why did you consider a close system for cooling , instead of using air cooler or cooling water ? 

To me you are looking for trouble and you will need specific chemical treatment . 

Good luck 

Breizh 

[J_Leo]

breizh,

 

Thank you. We don't have cooling water system at facility. Those were designed and installed during the project phase. Atlas Copco has both air cooled and water cooled system. I am guessing there are some advantages for using cooling water