HX Efficiency Questions

[bluepinebrewer]

Hello, we're a 3 BBL Nano about to open - wondering if I could get your feedback on knockout issues/process.

Our HX is a 60 plate counter chiller (pix attached) and we've been trying to maximize efficiency during wort transfer. We have been using nearly 200 gallons of water to cool down 100 gallons of wort in 45-60 mins. We're regulating the wort flow with a variable motor pump - no regulation/constriction on the water side. Our tap water is about 63 F. We've been reusing much of the water for cleaning and the next brew but it takes 60 mins to transfer. Is that water use and timeframe unusual for 3 BBL? I keep the temp at about 75 so I can inject O2 without Hot Wort Aeration. I thought maybe the variable would be hops that enter the plates and clog up the transfer but after each use we flush it out, we don't really see many hops coming out, just wort remnants. Does hose inner diameter have a significant impact on transfer efficiency? Rookie questions, but I'd appreciate any feedback, tips or a Heat Exchanger 101 FAQ.

Best Regards,

Paul

Paul Vieira
Peaks N Pines Brewing Co
Colorado Springs Co

[TGTimm]

63F is very warm for cooling water. When our domestic water went from our usual 45-47 up to 55 this summer, our knock-out times about doubled.

[bluepinebrewer]

Thanks Timm - wish I could change that but it's my handicap..... One of the things I'm considering is stashing the HX output water into a fermenter (I have 5) and chill it down to 40F for the next batch. I dug into several of the posts...I did see something to try. I don't have a constriction on the output of the HX. if I do cut that flow down and increase the back pressure in the HX and thereby force the water to spend more time with the wort, I might be able to pull more heat out of the transfer and as a result decrease the amount of water collected at the end of the process. I barely passed physics so I may be blowing smoke conceptually.

[jeffzearfoss]

Thanks Timm - wish I could change that but it's my handicap..... One of the things I'm considering is stashing the HX output water into a fermenter (I have 5) and chill it down to 40F for the next batch. I dug into several of the posts...I did see something to try. I don't have a constriction on the output of the HX. if I do cut that flow down and increase the back pressure in the HX and thereby force the water to spend more time with the wort, I might be able to pull more heat out of the transfer and as a result decrease the amount of water collected at the end of the process. I barely passed physics so I may be blowing smoke conceptually.

Hi Paul,

Do you have a glycol system? If so, what about a two stage HX? We don't have one yet, but it's the direction were going too.

Check out brew.thermaline.com, good calculator to size a system for you based on your situation.

Another option is a CLT in the walking, depending on space considerations and/or if you have a vessel currently not in use as you ramp up to full volume.

We're just across town, btw, nice to meet you!

Jeff

[bluepinebrewer]

Jeff, thanks for responding! Yes, we do have glycol on our fermenters. I've been thinking about direct chill system to HX but didn't want to overtax the system, particularly if I have a lager in active ferm and a couple of cold crashed ales conditioning. We have 6 brites coming in soon so I may consider one as a CLT. I'm trying to maximize my HX, gets frustrating trying to tweak everything to move the wort along efficiently and still keep wort temps down under 80. Didn't see your brewery name. Are you serving at the ACBF tomorrow?

Paul Vieira
Peaks N Pines Brewing Co
Colorado Springs Co

[TGTimm]

Using one of your jacketed vessels as a CLT should work just fine, as long as it's big enough to do the job. I'm betting that you'll use less than half as much water using 40 F instead of 63!

[bluepinebrewer]

That would be my nirvana Timm! We've been reusing the water by filling our HLT and MT but then we have pails of water when those get full.

[TGTimm]

Do you monitor the output water temp? I don't know off the cuff what the optimal temp change should be, but fooling around with both flow rates until the output water temp pretty much levels off should give you something near optimal.

Will you be pumping the cold water in, and using a VFD-equipped pump so you can control the feed rate?

[bluepinebrewer]

Timm, we haven't been but on your suggestion we will now. We've been using the "scientific squeeze method", meaning we squeeze the hose and determine heat or lack thereof. It varies quite a bit. Brewing a Pilz tomorrow so we get to test out these ideas. As for feed rate we have the VFD on the wort side, just using tap pressure for the cold side. First thing I plan to try is to restrict the output (post HX) flow to the capture tank to slow the flow down and backup pressure in the HX and reduce flow because there are times where the output water (reference above squeeze test) is warm, even cool. So I suspect when that happens it's just flowing too fast and not picking up heat at all. I'll let you know how it works. Thanks for the dialog! I really appreciate it!

[barleyfreak]

I had similar incoming water temp issues for my 7bbl system. W/O a CLT (or room for one), I was initially at the mercy of incoming city water temps which are in the low 50's in the winter and (gasp), over 70 in the summer. Not ok. So I ended up getting this and placing it at the end of our FV glycol loop for pre-chilling the incoming water. It helped a lot. I added a step to our summer SOP on brew days of shutting off calls from other tanks for an hour before knockout and then during knockout so that the pre-chiller had exclusive use of the reservoir and then setting the temps back. My summer KOs are still not as fast as winter, but with incoming 73 degree water and the pre-chiller we get ~50+ min KOs. In the winter, I get 35 min.

Dave

[wlw33]

Slow the flow of your wort while keeping the water at the same high rate. This will increase the wort's contact time and the water will subsequently take more heat with it. This is also good for when you're cleaning your Hx because you'll want your cleaning fluid to be going through the Hx at a faster rate than the wort.

[TGTimm]

Just for a reference, our cooling water output is around 140 F when our water in is in the mid-high 40s. Wort out temp is around 75 F, assuming everything is right. When the water in heated up this summer, our knock-out times almost doubled, and the output water temp went down to 100-120.

[bluepinebrewer]

thanks everyone for your help - all valuable. I'll let you know how I make out. I especially appreciate the temp figures Timm, that gives me a reference point.

one other quick question: is it necessary to flush/PBW and sanitize the Cold side of the HX? I read other HX cleaning links on here and the focus was on the wort side for obvious reasons. But the assumption is the cold side is never exposed to the wort so is sanitizing a necessity for that side of the HX?

[TGTimm]

Basically, no. We've been acid-washing the cold side every year or so, but that's because we have hideously high carbonate hardness in our water. When I last broke the HX open (ours is a plate and frame), over a year after the last acid wash, there was no scale present on the cold side, so we probably won't bother any more.

Of course, whether you sanitize the cold side depends on what you plan on doing with the cooling water. If it's going into the HLT, I doubt it matters.

[bluepinebrewer]

Roger that Timm, that's our target storage area so it will be heated eventually. we could send it to the fermenters and chill it down if we're still having issues.