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Thread: Evap barrel woes
06-29-2012, 10:28 AM #1
Evap barrel woes
Overview: we just took over service on three T/S (RAE) chillers. Theese three machines take care of cooling two electric motors. Due to the way they are piped one chiller per motor and one is a standby. Apparently in years past they have been wildly neglected due to lack of knowledge by the prior company unbeknownst to the customer. The chilled water loop was very neglected (when we cleaned tanks I expected to find fish)
Two of the machines had an out of this world approach. The evap barrels are loaded with god only knows on the water side.(refrigerant in the tubes) we changed the barrel on the worst machine, which is now the best. Now that they have two good running machines they would like us to experiment with the last one and try to salvage the barrel. They sent the removed barrel out to have it analyzed for rebuild. If worst comes to worst they will buy another new barrel but they want us to try a salvage operation. In September/October all piping will be replaced and repiped with three way valves and a new massive RTAC is waiting to be started and takeover. These three chillers are to be like new for reliable backups.
What we are thinking is cutting the barrel loose and doing a massive reverse fire hydrant flush to get anything out. Then switch over to a chemical flush. I am looking for a few opinions on: What chemical will be best for crud mud busting?
06-29-2012, 11:01 AM #2
So an open chill water loop with make up..
I would think scale remover definately. Ive never seen one so bad it had to be replaced. Maybe retubed but not condemned entirely.
06-29-2012, 11:25 AM #3
No make-up. It is an open loop. This setup was designed by a large electric motor company that knows motors not chillers. The design limit is sixty degree water and that is their setpoint so the motors dont sweat. I have not found any scale evidence. I do not want to use a descaler because I figured it would chew up exposed tubes and not touch barried tubes. I should have noted it runs 50/50 glycol. They said they have flushed and replaced the mix up to 6 times a year!(and it is a decent sized loop$$)
06-29-2012, 12:00 PM #4
Oh. High approache temps are usually indicitave of scale. If the ph is monitored correctly it shouldnt damage the tubes.
Other than that your high pressure high volume idea seems ok if its that bad. That and tube brushes.
06-29-2012, 12:11 PM #5
Indicative of not necessarily scale but fouling. I believe it's packed full of clay like biologic/iron mud. I can't brush it because the refrigerant is in the tube and the water is in the shell.
06-29-2012, 12:57 PM #6
By the way thanks for taking time to help. Have you used anything besides descaler for barrels because I have not. Wish refrigerant and water were reversed and I could just brush, but hey I do like a challenge. Our water samples of the loop were sent off today. Pulled four samples yesterday, one from this and the other three from totally different chilled water loops. The other three looked like fresh brew mountain dew, but this one looks like oil change after 10k miles in my Detroit diesel.