Need bigger glycol reservoir

[brain medicine]

I goofed on the chiller purchase. Bought two used chillers, refurbed by a vendor here. But i confused the two units, thought the 3hp unit had the bigger reservoir, turns out it was the 2hp unit we used for draft. Too late to change now. Vendor no help.

So even with a 5f temp range (30-35) the compressor is cycling often.


The only way i see to solve the issue is by going bigger on reservoir. Anybody know of sources for vessels that are insulated and would make good reservoir? Can be pressurized or not.

[Thirsty_Monk]

Insulated plastic vessels will do just fine. This is what pro chiller is using.

[Rushstop]

I used 55gal plastic drum with big coil running through it back to my small chiller then a different pump to move the glycol from 55gal drum through my glycol lines.

[brain medicine]

Insulated plastic vessels will do just fine. This is what pro chiller is using.

But do you know of a vendor? Or is this a diy project i need to undertake? Searching for “insulated storage tank” seems to only show results in the hundreds or thousands of gallons. Nothing small like wed need.

Someone mentioned an old/used electric water heater, apparently they come as small as 20-30 gals and hold pressure.

[UnFermentable]

I used 55gal plastic drum with big coil running through it back to my small chiller then a different pump to move the glycol from 55gal drum through my glycol lines.

I have seen something similar done with a 275 gallon IBC pallet tote and a home-made insulation job. Outlet was retrofitted to feed a 1.5HP CIP pump (replacement) and that pump actually cycled the loop, while the smaller pump (original process pump) simply cycled the reservoir through the chiller compressor. This system was running multiple 30bbl vessels. Certainly not a preferred solution, but totally doable.

I think there is a website called Plastic-Mart or something very similar where you can purchase cheap HDPE tanks in a variety of sizes and shapes. I believe they sell stands as well. You can pick up some insulation based on the R value you are looking for and wrap it, or spray it with expensive spray foam. Probably your best options overall.

Water heaters are usually ceramic bonded carbon steel and they will eventually contribute rust to your system. And could rust out and leak your very expensive glycol out.

[Thirsty_Monk]

But do you know of a vendor? Or is this a diy project i need to undertake? Searching for “insulated storage tank” seems to only show results in the hundreds or thousands of gallons. Nothing small like wed need.

Someone mentioned an old/used electric water heater, apparently they come as small as 20-30 gals and hold pressure.

ProChiller is using 20 Gal tank for 5hp chiller. Something like this:
https://m.plastic-mart.com/product/16772/norwesco-44846
PriChiller is shorter and fatter. If you have empty 30 Gal container from cleaning chemicals, that would work as well.

You would have to install a couple of bulkhead fittings.

[brain medicine]

Plastic mart, us plastics, etc are all options, i was hoping to find something preinsulated just to save time. Realistically the bulkheads are the bigger issue, making sure they dont leak.

In any case, as im digging into the chiller unit im realizing i have a potentially bigger issue. The damn pump is spitting out somewhere around like 50ish psi. We have had to throttle a ball valve at the process outlet nearly 3/4 of the way, as well as opening up the gate valve at the end of supply header to drop the pressure on tanks. Chiller also have a bypass valve right before the process outlet that jumpers to return line. I opened that sucker all the way and our gauge at the end of the loop was still at 25psi. And the ball valve we throttled sounds like a gringo belly with a case of montezumas revenge. No bueno. The results? FV wont get below 47, with glycol at 30-35f.

Im guessing the majority of the flow is just looping from reservoir to pump into bypass (due to throttled ball valve) and back into chilling circuit and around and around? If you hold the drop lines into tanks it feels like theres good movement tho. Im a bit baffled.

A 60psi pump pressure on a 3hp unit seems way out of whack for a brewery chiller, so i know this unit didnt start its life as a brewerry unit, but i assumed it was overhauled into a more appropriate set up. Maybe some folks might need extra pressure, buti think its hurting us. And the bypass relief does pretty much nothing. Maybe 5-8psi drop.

Now i feel i need to tackle the pump issue before i get into reservoir building. I did actually speak to vendor and he says keep throttling until we’re down near 15. Lets see how that goes.

[Rushstop]

Sounds like you have a pump for beer lines made for small "less then 3/8 lines to run in a trunk line to keep taplines cool" I have the same I just used a pressure reducing gate valve and 3/4 pex headers with 1/2 drops before I added my Larger reservoir now the the original pump runs through 100 ft coil in the reservoir and a hot water recalculation pump runs glycol from my reservoir to all my tanks. Im Running 5 3bbl FV 1 3bbl BT and 3 1bbl Fv with this set up I can get down to 36 deg in the BT

[TGTimm]

If your pump is for a beer dispensing cooler, it's probably a positive-displacement pump. If you have any unplanned restriction in a vessel jacket, the pump can easily damage the jacket.

If it's a PD pump, replace it with a centrifugal.

As for using a water heater tank for your glycol back, don't. The tank will be insulated with fiberglass or rock wool, and not air-tight, so you will accumulate a lot of condensation on the outer walls of the tank, causing it to rust from the outside in--not to mention making an unholy mess.

I've fabbed a couple of glycol backs by wrapping a plastic 55-gal drum with Armaflex sheets. Use lots of contact cement to be sure it's as air-tight as possible and it'll last you for many years--unless your brewery cat discovers how much fun it is to scratch the Armaflex off.

Bulkhead fittings are easy to find online, and very easy to install. Home-brew suppliers are a good place to look, and usually have ones with curved washers to match the curve of various vessels--like 55 gal drums.

[UnFermentable]

A better answer than the 55 gallon drum might be one or two marine coolers. Bulkhead those and they’re already insulated about as good as you could diy. A couple 150qt coolers would easily beat a 55 gallon drum in capacity and R-factor. Tight fitting lid, and easy to clean when needed.

[brain medicine]

the unit has a normal centrifugal pump. no idea where the idea of a draft line chiller came from.

after tinkering, I've come to conclude there's no way to make this thing work unless I get a VFD for the pump. lowest we could get the pressure on the header was 25, and that was with end-of-loop gate valve wide open, unit's process outlet valve cranked down until it was just off of cavitation, and the unit's internal bypass valve as open as possible. but we were not getting any flow into jackets with gate valve wide open. crank down the gate valve though and we're cooling again, but stalling out in the mid 40s, and pressure is back up to 25ish. either its just too much flow, not enough time for good heat exchange- or the unit's bypass is looping the new chilled fluid right back into the unit due to excessive back pressure. probably both.

so- I grabbed a cheap vfd and am waiting for manufacturer to give me the specs to program the drive for correct operation. I figure once we get the pressure down enough, we can close up the unit bypass valve and stop the looping within the unit. once the chilled fluid starts actually getting into our headers and tanks, im hoping that, along with proper pump output pressure that lets me utilize the gate valve as a choke point, stopping the unit bypass loop and getting suitable pressure differentials in the piping/tanks should do the trick.

one issue though- due to units' layout/design, its going to be a ROYAL pain in the ass to get to the pump motor and open it up enough to see the wiring connections inside the motor. since this is running off of.a VFD, does it matter which lead goes to which in terms of UVW? the unit is wired t1/2/3 (red, black, white) on control panel for leads to pump, so I just cut the line in half and spliced in the VFD. the t1/2/3 lines went into inputs of RST respectively. however the VFD output is UVW, and the sealed (wash down?) motor doesn't have any markings I can see to be able to tell which is UVW. im not sure I can really get in there to open it up and see which is UVW without doing a ton of work due to space constraints. does it matter? I thought it didn't once you use the VFD......?

[TGTimm]

If you got a decent VFD, you should be able to put a pressure sender in the output line to inform the VFD and keep your pressure constant with changing loads.

The output phase of the VFD is independent of the input. You can reverse two of the input leads without changing the direction of rotation of a motor on the output side. But you do need to be sure your motor is turning the right direction--usually clockwise. If it's turning backward, just swap two of the output lines on the VFD.

[brain medicine]

Well it took all night to decipher the manual written in some wonderful Chinglish, but i finally got it working. Down to about 800 rpms and about 15ish psi. So far so good. It says it has a port for remote sensor control, so we could add the pressure sensor later.

But tanks still stalling at 45ish. Reservoir says 30, no way im losing 15ish degrees in the loop. Thats too much. Finally dawned on us to check the accuracy of temp probe- off by 10f. so the whole time we thought the glycol was at 30 but really at 40, so a “stall” at 45 is actually pretty damn good. Bypassed the temp probe with new sensor, all is good.

Lesson learned.