Thanks for the quick answer! I'm planning to have a 1/2" pickup tube to collect the water pretty close to the bottom of the kettle, and run it continuously through one of the pumps wide open back to an inlet at the top with a short tube angled to one side for just the reason you describe. Should create reasonable circulation. Other than thermal transfer / possible overheating of the kettle what kind of bad things could happen if it did come in contact? I'm not planning for it to, of course, but just curious.
Anyone happen to know where to find formulas to calculate exactly how many feet of 1/2" stainless non convoluted tubing is needed to get almost 100% thermal transfer in a HERMS coil? I know Kal uses 50 ft in his coil and says the output is almost always the same temp as his HLT water. How much less can I get away with? Again, trying to minimize height without losing functionality. I'm planning to get a custom coil from stainlessbrewing - that's one component I've decided to splurge and not hassle with the DIY factor too much . Have read too many horror stories about stainless coil attempts...
We had originally used a Chinziller Counteflow Cooling Coil as a modified HERMS setup. We eventually brought a stainless coil HERMS. We have actually gone back to the Chin Chiller setup as it seems to be easier to control than a Coil in a tank. We went with a smaller HLT with an electric element and only use about 4 US Gal for Hot Water. We called the big tank "moving the elephant". Of Course this takes two pumps instead of one, but the control is very quick and you can either quickly cool or heat the HERMS water bath.
Basically we turned the Chinziller into a Heater instead of a Cooler. We now use the Stainless coil to cool beer by putting it in an Ice bath (Jockey Box).
BTW, Copper is a better heat conductor than SS. You could buy (or make) a Copper Wort Chiller and use as a HERMS Coil. Copper is easy to put on fittings and learning to "sweat" a joint is fairly quick.
Thanks for the further thoughts. I've read quite a bit on the difference in thermal transfer characteristics between copper and 304 stainless. The significantly thinner wall of the stainless is commonly thought to help offset the difference to some degree, though it can never match copper of course. I've also sweated plenty of copper connections, and comfortable with that process if I go that route. My only concern with the stainless is the bending it smoothly part. I know I definitely want to keep it to 2 pumps, and I also know I don't want a 4th container. I like the idea of being able to throw caustic chemicals through the SS for cleaning if desired.
I just modified one of my 5 gallon recipes to 10 gallon on my spreadsheet to see some numbers. For my house IPA I'll need to have about 9 gallons for the mash for a 1.5 grist ratio, with ~8 gallons of sparge water ready to collect 13 gallons pre-boil. Using the standard formulas, my 9kW heater can heat those 8 gallons of sparge water from 146F (I mash low on this one to dry it out) up to 168 (generally accepted 'mash-out' temp and my preferred sparge temp) in 3.2 minutes using the standard water heat formulas. electricbrewery clones seem to get in the ~1-1.25 Gpm flow rate through the HERMS coil with a well designed false bottom. That means my entire 10 gallons of mash liquid will be recirculated in 8-10 minutes. That number doesn't vary with the size of the water bath, of course, but rather with mashtun design.
So I just answered my own question by talking out loud again. I'll go with the 50' SS coil. It's only 7" tall. Add 2" for space above and below the heating element. In my diameter kettle, 9" of water will be ~11 gallons required to cover the coil. My element will take 4.3 minutes to raise the temp from 146 to 168 for that volume. That's about half the time the mash takes to recirculate, so ~1.5 times the recirculation time should result in almost a complete temperature raise. Even if I could raise the temp of the water instantly, that means 15 minutes instead of 10 minutes to heat the mash. Of course this is all perfect world 100% transfer blah, blah. Real values will be a few minutes slower, but still perfectly acceptable.
One nice thing about the stainless vs. copper... is Stainless doesn't get tarnished like copper. Stanless Brewing does a great job. I have their 1/2" 50ft wort chiller and it's awesome.
I saw a SS Counter Flow Chiller somewhere and thought about buying it because the copper does tranish and SS would be better for Caustic Cleaners. Almost everything we have is SS so it would be better for looks. I would agree the Heat transfer difference is minimal in this size setup. I actually think the SS Coil I have is "bent" wrong as the flow is poor and that is the reason we went back to the Chinzilla. Our Large HLT with HERMS coil is also propane so going with a smaller 9 gal Stout Brew Kettle with Electric was an easy out. Brewer's Hardware has the fittings and ferrules for the Electric Elements. I really like the way they connect the Electric to the Element.
Those Brewer's Hardware tri-clover adapters do look pretty cool. I'm not planning on having any welding done on the SS kettles, though, so I'm going to be looking at weldless fittings. I couldn't find one on their site, am I just blind? I liked the one I saw somewhere that adapted a sugar shaker like you see at diners, too.
pngaudioguy wrote:Those Brewer's Hardware tri-clover adapters do look pretty cool. I'm not planning on having any welding done on the SS kettles, though, so I'm going to be looking at weldless fittings. I couldn't find one on their site, am I just blind? I liked the one I saw somewhere that adapted a sugar shaker like you see at diners, too.
very trick new fittings, 2" TC weldess fittings that include custom-made silicone gaskets, not just o-rings, $40... I bought a couple and they are super nice machining quality.. and a camco ripple fits through easily. http://stilldragon.com/index.php/2-tric ... tting.html
Yikes! $76 per kettle? They are pretty and shiny, but I'm sure I can get a quality weldless mount for my heater elements for quite a bit less than that somewhere! I won't need to be having easy on/off access, so the tri-clamp has minimal interest to me in this application.
. Have read too many horror stories about stainless coil attempts...
