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No Cooling Water flow

Posted: Wed Mar 07, 2012 3:17 am
by ChEngJr
Hi everyone, this is my first post in the forum, so please be kind...

This is my issue: I'm working in rubber plant and I have a problem in the finishing product lines, the cooling water return line from a hydraulic press (in fact are really 8 presses) is no flowing to the CWR header so it causes that hydraulic oil overheat and shutdown the lines.

I've been asked to solve this but I have no idea where to start, unfortunately there is no PFD available of the cooling water distribution, what I know for sure is that the cooling water supply header pressure is 4.1 kg/cm2g, the water flow from each press is about 16 gpm (needs to be checked) and the pipe diameter is 1 1/2", to maintain the lines working we are discharging the water to the drain.

Can someone please point me in the right direction. I'm not a process engineer and any help would be much appreciated. Thanks in advance.

Re: No Cooling Water flow

Posted: Wed Mar 07, 2012 6:07 pm
by admin
Maybe the pipe is filled with dirt if hard water is used and it wasn't softened over long time?

Re: No Cooling Water flow

Posted: Thu Mar 08, 2012 3:43 pm
by Kings2552
Are you using some untreated water source like from a lake or river. Even if it is from a cooling tower, fouling is likely to happen.

Are your oil coolers shell and tube heatexchangers? It should be easy to clean the tubes with a high pressure washer.

Re: No Cooling Water flow

Posted: Thu Mar 08, 2012 4:38 pm
by ChEngJr
The water source is a cooling tower, and I'm waiting for some information from our water supplier, the exchangers type are plate and frame.

Re: No Cooling Water flow

Posted: Thu May 31, 2012 8:41 pm
by dmon53
I had very similar problem. I have been using you Pressure drop and flow rate calculator for a cooling problem on our hydraulic system. The cooling system is spec'd at 20 GPM min (chill water temp is about 60 deg F) and is supplied by about 5 ft of 1" copper pipe connected to a 2" header. Header pressure is about 21 psi. We ended up replacing all of the cooling components because, as it turns out, it was plumbed backwards when installed (water supply was connected directly to the heat exchanger and water flowed thru the heat exchanger, thru the thermostat - senses oil temp, and finally thru the y-strained). Hence the Y-strainer didn't do it's job over the last 6 years and the heat exchanger and thermostat plugged up. I had a suspicion that there was a problem with the chill water supply so I installed 2 pressure gauges and a flow meter. Max flow was 11 GPM, the supply pressure was 21 PSI and the return header pressure was 19 PSI. This indicates that:
1) the flow through the return header from the other components of the chill water system (water is supplied throughout the building for cooling) is too high for the system to handle (Return header pipe is too small)
2) or the supply line pressure is lower than it should be.
My best guess is that our facilities workers shut down a pump to save energy. But at least I proved that the problem isn't our system.