Cooling Setup for Bubble Plate

CothermanDistilling

I could do a 4-6 hour run on a dash on a keg boiler with city water (80F) using the danfoss valve and just barely go over a 60 gallon plastic barrel. first run will just be to fill the things on city water, then will see how long they take to cool to ambient, I may only run the 380L once a week to start, by the time I run it more, I can have my chiller finished..

what do people use in the water for fungus? anyone use something like water-wetter for better heat transfer?

grim

Skip the water wetter.

You can use small amounts of bleach. You'll need an ORP/Redox pen meter to determine how much to add, but a little goes a long way.

Aim for an ORP of 350mv to start, this is on the low end of what is typically spec'ed for cooling towers.

Ozone injection is easier long term, but much more expensive up front.

The ORP meter shouldn't run you more than 30 bucks.

Obviously the water is no longer potable after you do this. More is not better, and you probably want to occasionally dump and sanitize the cooling system instead of resorting to near nuclear chemical levels in cooling water running that near your product.

Smaug

@Littlechicago said: With his chiller, Cotherman will have no problem with one tank. I am doing a submerged 3 ton evap coil (actually undersized for the chiller) with the identical chiller and its keeping up with cooling duties with no problem. Return is going on the top of the ibc and intake for my 1.5hp pool pump is at the bottom. This pump has two pool eye returns with a 1/2" supply line going to pc and dephleg. Doing double duty as a circulation and supply pump. A distillery local to me in Buffalo is only running a small 1hp aquarium chiller on 8+hr runs with no problem on a single ibc.

That's good news/info Littlechicago.

Smaug

@grim said: Skip the water wetter.

You can use small amounts of bleach. You'll need an ORP/Redox pen meter to determine how much to add, but a little goes a long way.

Aim for an ORP of 350mv to start, this is on the low end of what is typically spec'ed for cooling towers.

Ozone injection is easier long term, but much more expensive up front.

The ORP meter shouldn't run you more than 30 bucks.

Obviously the water is no longer potable after you do this. More is not better, and you probably want to occasionally dump and sanitize the cooling system instead of resorting to near nuclear chemical levels in cooling water running that near your product.

Can treat the water like pool water and adjust accordingly for calcium hardness and the like. Calcium will mitigate the corrosive behavior of the water/bleach.

Manofconstantsorrow

@Smaug public water works add chlorine i.e. bleach to potable city water in PPM for bacteria control which is all that is needed here, so even if it were corrosive the effects are so minuet that we will all be dead and gone before a SS delphleg would even develop a hole in it IMHO.

grim

I'll still argue the ORP meter is cheap insurance, just dip it in every few days and it'll tell you when to add a bit more bleach or ozone.

punkin

I'd certainly rather treat it at potable levels rather than pool levels.

CothermanDistilling

I think a friend has a stainless ozone generator tube in his scrap pile that he offered me one time... but afraid of ozone treated water eating metal???

I do have that copper dephleg (doh!) and a copper heat exchanger...

grim

That's why you monitor the ORP, if you are using ozone you'll have an ORP controller instead of the meter.

CothermanDistilling

@grim - you are making my brain hurt!

Ozone For Cooling Tower Systems - An Update And Lessons Learned At The Kennedy Space Center (PDF)

googe

I've tried every way known to.man, trying to get the rignt config!. Like.others have said it's personal choice. I do think feeding the rc with water closest to operating temps is a good time saver and would run better, achieving that is not easy though. Unless you had a dedicated tank, heated to takeoff temps that feeds the rc. That would be great, something you can ajust temps.on. I have mine setup so coolent enters the base of the PC, out the top, into a tee joint. My feed line from.the tank is split in two, one goes to the PC,the other to the rc. Both outlets meet at the tee and exit there. Seems to work.well with minimal valves etc.

CothermanDistilling

If you have two tanks, one half full, the other full, room temp water in both. Recirc the 1/2 full one through the RC during heads compression at a flow (or power level if fixed flow) just enough to get full reflux. This tank should be warm after heads compression. When you start taking product, run the tank of cool water through the PC and into the half full tank, trying to come into the tank slightly below the tank temp to have a stable RC temp You will have to take measurements with a meter or a bucket so you don't run out of water, and may need larger containers, but the theory seems solid... next time you either pump the half back or switch connections. You may want only 1/4 full also..

Lloyd

Sounds solid to me. Matching the tank's volume and it's temperature to the still's demand is the science part. But real run experience seems to define our science, yes?
I'm handicapped here as I use mains water but if I could I'd switch to tank water.

If I was commercial I'd devise a way to use the expensive hot water generated instead of feeling guilty by letting it go down the drain, wasted.

dad

If you used recirculated dirty water for cooling, what about a final rinse of city water at the end of the day?

I send my 140 F heated city water from the RC to the hot tub...usually only replaces about 1/5 per run. Then the overflow from the hot tub goes to the garden and lawn. Keeps the hot tub fresh.

I have a 4 acre pond within 50 yards, but haven't set up the pump to get it to the still.

CothermanDistilling

you could plumb all non-drinking water(showers, toilets, laundry) for your house from a small well pump and pressure tank hooked to your (clean) tanks... but you still need tanks..... and approval from the misses...

what if we eliminated water altogether and used refrigerant?

Myles

@googe you just described a variation of a charentais still. In the Charentais the product vapour pre warms the next boiler charge in a header tank before it gets to the product condenser.

I see no reason why you couldn't have a header tank for your reflux condenser with or without a second pump. Simply heat it with a coil split off your PC output, and add a thermostatic valve for temperature control.

There are other ways to do it also but it depends on whether you want your RC loop independent of your PC loop, or if they can use the same reservoir.

grim

If you've got single use coolant, like city water, just use larger, or taller condensers everywhere, for a given knock down rate, you can use lower flow and get a higher output coolant temperature.

An easy way to visualize this is just stack 2 or 3 SD product condensers together. Feeding from the bottom, the lowest condenser would be most effective, the next above, less so, and the top condenser the least effective. But by running the coolant upwards in a daisy-chain fashion, the top condenser is acting as a vapor pre-cooler run off your higher temperature waste coolant.

There is a point of diminishing returns.

But really what you are doing here is making an upfront investment in a higher surface area heat exchanger and hoping you'll get payback through the reduced water consumption (or ecological good-will).