Good Morning District Great Plains!
I hope that in addition to this District Forum, you are all subscribed to the MBAA Ask the Brewmasters Digest. The post below popped up yesterday and I can pretty much guarantee that everyone who was able to attend our most recent technical meeting new exactly what the answer was, having heard Ashton Lewis's excellent talk on fluid dynamics, which you can all access in the presentation archives. I point this out as a very real, practical benefit of your membership and to point out the value of these technical meetings. You can subscribe the the Digest under the "My Connections" tab under your MBAA Account info. ~Cheers!
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Original Message:
Sent: 12-09-2022 16:46
From: Aaron Dahl
Subject: Hot liquor pump pressure loss
All,
I have a pump problem (shocking) that I have been dealing with/living with for several months now, and I'm hoping to find a remedy for it after trying everything to eliminate this ghost in the machine. My hot liquor pump consistently loses pressure during sparging/knockout loop sterilization, when water temperature has increased and hot liquor volume has decreased. The pump behaves fine during vessel rinsing and mash in, but once I've increased the temp of the hot liquor for sparging (170) it gradually loses pressure until the flow out of the sparge is barely a trickle. Looking at the pump curve, like most pumps there is a loss of pressure with increased temperature, but this is an incredibly drastic condition. After I've completed wort knockout, and the water volume in the hot liquor tank has increased, full pressure resumes during final vessel rinsing. The water temp has decreased at this point and usually lands around 160.
I've replaced the seal kit on the pump, tightened and reseated every connection to and from the pump to eliminate any air being pulled in, removed the check valve (piping into brewhouse passes through two) on the brewhouse side, and installed a vortex breaker on the drain of the HLT to help eliminate any vortexes being pulled into the pump. I've talked to the brewhouse manufacturer (BrauKon), pump manufacturer (Grundfos), local service provider for the pump, and about every brewer in town about this issue, and nothing we have tried has solved this problem.
Any ideas would be greatly appreciated, thanks for any help!
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Aaron Dahl
Head Brewer
Golden Age Beer
Homestead, PA
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Steve Bradt
Hopsteiner
Craft Sales Representative
President, MBAA District Great Plains
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