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On cooling mash / wort...

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We've recently ordered a 2500 liter mash cooker with removable wedgewire false bottom.  In the past, with our 150 gallon cooker we've used a various mishmash/hodgepodge -- the most efficient of which is a 75' long -  1" diameter copper coil with tri-clamp fittings on each end. We transfer the mash  from the cooker into an HDPE tote, drop in the coil, turn on the muni water supply, stir the mash and wait... and wait. We can usually get it from glucoAm temp to yeast pitch temp in and hour or so. Results are much worse in the summer when ground water temps hover around 68F.

For our expansion (thanks to Mike @ MG Thermal Consulting) we'll have a nice chilled water system. I'd like to hear some feedback on various methods of mash chilling. After much reading the two options I've settled on are:

1. Use the existing mash cooker jacket and adapt piping to enable chilled water flow through the jacket

2. Standalone tubular cooler (think a long liebig condenser) 

For #2, we've received a quote for $3,850 for the tubular which will consist of 8 (approx) 6' sections of 3" over 2" stainless with TC fittings to facilitate disassembly and cleaning.  I have a number of concerns about this, the least of which how much cooling will occur in the middle 1" of mash -- is 2" too large? should it be 3" over 1½"? Can our mash pump handle the load?  Additionally, it doesn't thrill me to have another piece of equipment to trip over, move around, and clean.

As for #1, I've heard of folks doing this but have no first (or eve second) hand knowledge.  I can't imagine it would cost more than $3,850 for the needed valves  & piping. If my (grossly generalized) calcs are correct, I need to remove about a half-millon BTUs from the mash to get it to pitching temps ((185 - 85) * 600 gallons * 8.4 lbs / gallon).  

I digress...

If any here can share your methods for large-volume mash cooling or other thoughts I'd be appreciative.

 

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I have been down this same bumpy road and settled on a custom built shell and tube.  MG may have built it.....take a look on the used SS equipment market.

Both ends of the shell can come off so you can clean the straight through tubes and the "u" ---tubes are short enough to clean if they get plugged. I think we only fouled this thing once (that I know of).


We have used and old milk cooler the runs refrigerated water down the side walls with an agitator to accelerate thermal transfer but we needed more than one run a day...

DIY'd a 2" finned copper tube  with forced air (ambient) cooling which worked pretty well (car radiator on steroids) but again fouling killed this idea off....or was it frozen and popped (?)....still using one of these to cool hot non-contact cooling water from the condensers....non-contact since we recover some of this pre-heated water for the next cook

We have used a "used" tri-tube chiller which was fine accept that our grain in mash was too thick and we were constantly fighting a plugged....so depends on the viscosity of your current or future mashed.  

The space for mash to flow has always been the killer for us fouling whatever we tried...but if you have a mash with no solids from your  new shiny wedge wire cooker....

so agitated milk cooler, forced air finned tube, used tri-axial tube in tube, 3" dia mash shell and tube---cooling to ambient with cooling tower and now adding heat powered adsorption chiller to shell side when ambient or delta t is insufficient for production volumes

Xylanase will do wonders to heat transfer and viscosity if you are running rye

 

 

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We use a shell and tube system picked out by our thermo engineer to meet process requirements (500 gallons from 212 to ~150 in 30 minutes with 400 gallons of well water preheated to at least 110 for the next cook. Followed by a 150 to Ferm temp drop in less than an hour done with the chiller)

Our shell and tube utilizes 1 inch in and outs for product flow, but the tubes are even smaller 3/4 or maybe 1/2 inch. Shell and tube are generally more efficient than the tube and tube you are describing or jackets for cooling. However they are more difficult to clean and there is the potential to plug. Since we had our cooker fabricated we weighed the cost of adding a jacket to the tank to the cost and flexibility of an external exchanger. While the exchanger cost more than the jacket, we know it works for our process and we have the option for using it for other purposes too. 

However if I had a mash cooker with a jacket installed I would weigh the labor costs of utilizing the jacket (hrs per cook needed to cool) to that of a properly sized exchanger purchased in addition. If you can save an hour with the exchanger great, but how many cooks does it take to pay for itself and do you use it for anything else?

Per the tube and tube you are talking about, my understanding is, the outside tube you want as tight to the inner as possible to maximize exchange rate, narrower inner tubes and increased length increase surface area, increasing but exchange. Tube in tube is typically more expensive and larger than the equivalent shell and tube, but they are easier to clean.

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Indy, I'd be very cautious of using the same jacket for heating & cooling.

Lots of potential problems... boiler water contaminated from cooling water, thermal stress cracking trashing your tun/tank, corrosion of any pipes/valves that contain both steam & water.  I worked on a steam curing system that had water cooling as you describe and it was a maintenance nightmare.  We were operating at higher temperatures, but unless you have 316 stainless jackets and all copper or stainless piping I would anticipate premature failures.  But hey, sometimes the $ saved pays for the replacement and/or repairs.

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You have more options if you are simply cooling wort or non-whiskey liquids.  I most commonly recommend the Trident U-tube, for whiskey mash- they had the unit designed by a PE and have great success with it.

Jackets can be problematic for larger mash tuns above 500 Gal, and generally an external exchanger is used or even added as a booster.

Cooling with a coil dipped into a fermenter with mash because the circulation is not there for the mash over the tubes, unless you constantly pump the mash around, and even then you really can't do the job 100%.

When  you get into very large mash tuns, "wide gap" plate exchangers are used as well, but the starting price tag on these is over $15K for the smallest ones I've quoted.

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I was running my 2000L tote with the steam jacket acting as a cooling jacket and it worked fine.  Winter crash time on a mash (400 gallons water 1000# grain) was about an hour and longer in the summer.  I just upgraded to 4000L cooker and will start the same way but I am guessing it is gonna suck doing it this way.  Way back when I quoted a tube and tube through Thermaline and it seemed pretty reasonable (I know Quincy St. is using one, care to weigh in BlueStar?).  I have an extra condenser (19 1" tubes, 5 ft on a 8" shell) and am debating running this as a dedicated cooler.  The debate is run it as pure shell and tube or put some sort of U-tubes on the end and have it go on one continuous path (though a labor intensive mod and if you plug it you are f*cked).  I used it on small mashes when I was doing 60 gallon batches and it worked fine but it was hard to keep clean.  I didn't think of putting easy to use manways on the ends but had them bolt on which made the whole breakdown a PITA.  I think putting a manway on both ends and on the input end have it split the tubes in half could work well in theory and you could have the mash pump in and out of one side...Still thinking this through and would love anyone's input.

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You could do your man-way system, and a baffle setup on each side to great a multi pass system that is easy to clean and easy to unplug... 

Details: far 'u' side has a single vertical divider, product side has horizontal divider and a vertical divider on top. This would be a 4 pass. In top left, flips on left side on the opposite, returns to product side flips on bottom, flips on right side opposite, out top right. Open man ways to 'floss' each tube with a pipe cleaner on a string/stick for thourough cleaning.

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Sounds like a great idea Tom.  I will see what a fabricator will want to charge me to manufacture the ends and try to post a followup on how it goes.  It has been awhile since I did the hx calculations but I imagine that as big as the thing is it is probably still too small for a single pass on that size system in a reasonable flow rate.  Frankly though, if it is too small I can use both the jacket and the tube and shell and for sure get the knockdown time pretty reasonable.  Even if one ended up with 2 tube and shells stacked or side by side it would still have a pretty small footprint.  

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I bought the parts to put together a fold back style tube in tube cooler but haven't had the time to put it together.

Stilldragon sells the copper to triclamp sweat on fittings for pretty cheap - was planning to fold back a few 6 or 8 foot pipe sections joined with stainless triclamp 180s.  You can use pipe reducers and tees on a larger 3" copper tube for the outer jacket.  Nice thing is you can easily use thinner DWV on the outer jacket.  Only real downside is the price of copper.

That $3800 quote seems very reasonable if it's good quality sanitary welding.

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You have more options if you are simply cooling wort or non-whiskey liquids.  I most commonly recommend the Trident U-tube, for whiskey mash- they had the unit designed by a PE and have great success with it.

Jackets can be problematic for larger mash tuns above 500 Gal, and generally an external exchanger is used or even added as a booster.

Cooling with a coil dipped into a fermenter with mash because the circulation is not there for the mash over the tubes, unless you constantly pump the mash around, and even then you really can't do the job 100%.

When  you get into very large mash tuns, "wide gap" plate exchangers are used as well, but the starting price tag on these is over $15K for the smallest ones I've quoted.

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I have several Mash tuns out there with the jacket used for both steam heat and mash cooling with well water with no issues, however you cannot run glycol in the jacket.  I have sold them with built in cooling coils and some of my customers get great results by adding cold water directly to the mash to crash cool.   If you have a strong enough agitator (my mash tuns do) you can leave 1/2 of the water out of your mash and crash cool by adding cold water directly to the mash.  We also sell tube and shell heat exchangers at  much better price than my competitors.  email me paul@distillery-equipment.com  web sites http://distillery-equipment.com  http:/moonshine-stills.co

 

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