Glycol System Down

While we were waiting to get our brewing license from the NJ ABC we cleaned and passivated our new stainless steel fermentation tanks.  After that we decided to fill the tanks with water to test how fast they cooled down to conditioning temperature so would have an idea of cooling rates.  We had started up the chiller before to test it, but once it seemed to be working fine we shut it down.  We ran the chiller over night, which was the first time we left it running for any length of time.  

When we came back in the morning the chiller had tripped a low pressure setting and stopped working so our tanks never got cold which clearly indicated a problem with the system.  We spent the next few days working on the phone with the chiller manufacturer, our equipment supplier and neither had any idea what was causing the problem.  We kept trying solutions but the pressure would always drop tripping the cut off before we would get the temperature down.  Finally we narrowed the problem down to an issue with the flow. 

While we were trying to solve this problem, we got the word from NJ ABC that we could start brewing.  So now we were officially able to brew but couldn’t until we fixed this issue. 

We called in a refrigeration specialist down to see if he could troubleshoot the problem.   He thought it might be a faulty valve so we replaced it in the hopes that it would fix the problem. It helped, but unfortunately the flow rate was still restricted enough that the system wouldn’t work.  

On top of that it was a holiday weekend, so we had to wait until Tuesday to try anything new.  We were told to try and bleed some air out of the system over the weekend and that may help.  By Tuesday the system still wasn’t working right.
    

After checking every part in the chiller unit and finding nothing wrong we decided that the restriction had to be from too much air trapped in the pipes.  We decided to add another air eliminator to the other part of the piping where the air seemed trapped to increase the flow.  Once we added that, it allowed the air to slowly drain from the part of the system that it was trapped in and the tanks began to cool a bit.  

Ultimately the problem was poor piping layout and a faulty start up, both handed by our plumber / steam guy.  When he built the system he put in a ton of unnecessary elbow and turns where air could get trapped and when he started it up he didn’t flush out the air before filling it with glycol.  This caused large amounts of air to get caught in the jackets and piping.

Once the additional eliminator was added the chiller started working great, but now we have to wait for all the air to drain out of the system and see if the problem corrects itself.