Chilling process water

[Classick]

Hey all,

i was just curious if anyone is using chilled process water, and if so, what machine/technology are you using under what conditions and volumes.

I am located in the bay area, which, 70% of the time has perfect conditions for distilling. our ground water here runs at about 58-64 degrees during fall - spring.. but during the summer months, it gets as high as 68. This drastically reduces the efficacy of our distilling.

I am searching out solutions such as using evaporaters in a closed loop system, or realtime cooling of ground water... etc.

If we use a closed loop system, there probably needs to be a tank that can hold the required volumn of process water for a days production, then i guess chill it overnight for use the next day, or something to that effect.

Right now, i think we are using about 800 - 1000 liters of h20 a day, typically between 60-80 liters per hour.

if anyone has some suggestions or advice, that would be great.

Cheers

[BWFiggins]

Dear Mr Classick,

If your condensor is efficient in design, than all you'll need is a trickle of tap water, even in the dog days of summer. Mine is 24" x 3", but has thirty 3/8" pathways, with each surrounded by a water bath. I can build one for you. It is pictured at www.DynamicAlambic.com under "DISTILLERY".

All the best,

Rusty

[Classick]

Dear Mr Classick,

If your condensor is efficient in design, than all you'll need is a trickle of tap water, even in the dog days of summer. Mine is 24" x 3", but has thirty 3/8" pathways, with each surrounded by a water bath. I can build one for you. It is pictured at www.DynamicAlambic.com under "DISTILLERY".

All the best,

Rusty

I appreciate the offer, but perhaps i should clarify...

I am not talking about the condenser water, that is more than effective at most temps.

We have a system unique to our still that is basically a secondary inline distillation. (pictured below just above my fathers head)

Basically in this analyzer there is process water on one side, and spirit vapor on the other. by running cold water through one side, the heavier water molecules are attracted out of the vapor and we get a more refined vapor sent to the condenser. Obviously the colder the water, the more attractive the separation plate becomes and the less water we have to use to be as efficient.

Either way, how the water is used is unimportant... the problem remains the same. I am still looking for cooling solutions for our still.

Thanks for the offer to help though, it is appreciated.

[delaware_phoenix]

Don't know enough engineering to say whether it's better to chill the 60-80 liters/hour or chill the 1000 liters. If the latter you'll have to keep it chilled. Perhaps a 300 gallon SS bulk milk tank with refrigerator/compressor. That way you can have a thermostat to keep it at the desired temperature.

Depending on where you are located, an evaporative cooling system might work. Or also an industrial chiller.

[delaware_phoenix]

Another DIY idea is use a refrigerator and install a 10-20 gallon tank in it, plumb through the walls for the lines and use a pump to push the water with valves to control flowrate. Don't know if this would keep up with the overall cooling needs.

[Classick]

Another DIY idea is use a refrigerator and install a 10-20 gallon tank in it, plumb through the walls for the lines and use a pump to push the water with valves to control flowrate. Don't know if this would keep up with the overall cooling needs.

hehe gotta love DIY thinkers... i like it... Jocky Box style... unfortunately, i dont think we can have something electronic plugged in so close to the still due to local fire codes.... but it is an idea ill have to think about. thanks

[Denver Distiller]

All you would need is an insulated and jacketed cold liquor tank, a pump, and a glycol chiller. It's possible to use a chilled glycol loop directly, but it'd be a headache to balance it for consistent runs. If you used a CLT, you could use a fixed temperature, and capture the warmed water for mashing, or for cleaning.

You can get a CLT made for you from places like jnnw.com or local to you, Santa Rosa Steel www.srss.com

Or....you could find one used. They're a bit tough to pick up, because they are usually sold with an entire brewhouse for brewing beer.

probrewer.com has a classified section for used equipment. http://probrewer.com/vbulletin/forumdisplay.php?forumid=26

Cheers.

[Double G]

Dear Mr Classick,

If your condensor is efficient in design, than all you'll need is a trickle of tap water, even in the dog days of summer. Mine is 24" x 3", but has thirty 3/8" pathways, with each surrounded by a water bath. I can build one for you. It is pictured at www.DynamicAlambic.com under "DISTILLERY".

All the best,

Rusty

The link to your condenser photo is no longer working, perchance could you repost the picture?

Thanks,

Double G

[MG Thermal Consulting]

A refrigeration chiller that can chill a large tank (PVC would be least expensive unless you can pick up something used) is the typical solution if you have time to chill process water overnight. You can get to 32F with some chillers with water (a coil in tank designed evaporator). You can continue to run the chiller while the tank water is used by the process the next day- you will lose ground on the tank temp, but if you size it right, it won't get to the 68F water or whatever temp you cannot properly function.

This is typical of the way bakeries have batch cooled water for large mixers, chiling the city water between batches of dough mixing.

You''ll need pumps as well, one for circulating the water to and from the chiller and the second for the process. Pressure reducing valve for the city water inlet to the process reservoir. The tank should be insulated so you don't lose ground on temp.

I've heard of old bulk milk tanks being used for this and many other purposes, not as efficient, but less expensive if you can pick one up cheap. just get the refrigerant compressor to match, but BEWARE, most of the old tanks used R-12 refrigerant and compressors mineral based oil, so you have oil inside the tank coils and it would be near impossible to flush out to use present day non-mineral oil type compressors- the result will be a burned out compressor motor. The same holds true for R-502. The compressor manufacturer usually will not honor warranty if they find the oils are mixed. Have a good refrigerantion mechanic in the family!

[MG Thermal Consulting]

I have a product that will be available next year that will act as a drycooler with an evaporative deck add-on so that you can reach an approach temperature of 7 degrees (ambient wet bulb plus desired output temp). If you can't find an old bulk milk tank that you can chill water in during summer, the ideal is a small booster refrigeration chiller (portable with reservoir and circulator pump) and a brazed plate water to water exchanger to chill the well or muny water the few degrees you need to get to the point you need in colder months. You would need to drain the water out of the chiller during non-use below frweezing outdoor temps.

I recently talked to someone who picked up a used bulk milk tank fairly cheaply, so it was a good deal for him.

Good luck to you.

Mike

[Charles@AEppelTreow]

Mike, I'd like to get your opinion on a DIY chiller question. Or two. If you're willing.

Background:

I've moved my little 20 gal Coln Wilson still to a separate product condenser on a recirculating loop, much as you describe above. I run from the condenser, through the original through-the-column lines that served as the original chiller inlet/outlet and physical support. They also generate more reflux. From there to the chiller and then back to the 'CLT'. One loop.

The chiller is a small commerical aquarium chiller. Advertized at 18 kBTU - but I suspect that was generous. The chiller draws about 11A at 110V. The water flow is via 1/2" hoses. I'm guessing 60-100 gph.

Right now I'm using a 100 gallon resevoir. The size required to stay under the flashpoint the whole run surprised me.

The other things is that the per pass temperature drop is about 2F. I really have to drop the flow rate to get any more than that, and I can't get lots more, anyway.

Okay - my two questions.

1) Would I be better off with two loops? I'm running the warmest water through the chiller on my chemist's notion that more dT would help the chiller move more heat. But I'm a biochemist, not a ChemE.

2) Do I really need to be moving LOTS more volume through that chiller? The manual talks about 400-500 gph. But that's for a fish tank where you need to move lots of heat, but not have the return temp shocking cold, I think.

Charles

[MG Thermal Consulting]

I am not familiar with the construction of aquarium chillers, but talking in terms of a traditional refrigerated chiller, this is how flow rate affects reaching "nominal capacity".

If a chiller is "rated" at 18,000 btu/hr, at a particular set point, usually the flow rate is somewhere stated as well. In this case it is 500 GPH which translates to about the maximum flow for a 1/2" pipe. I don't think this is what you have though- I have ratings for a 1/2 HP chiller @ 230/1/60 with a circulating pump being 10 amps and between 5,000 and 8,000 btu/hr depending on the outlet temp.

The 60 GPH flow is about right for a 1/2 HP chiller which will chill the water 10 degrees. There is an inverse proportion between GPM and chilled water TD within the effectiveness of a given refrigeration heat exchanger, if you spped up the flow, the TD drops- but here's the kicker- there usually only a small range the chiller's heat exchanger will perform well and that is usually the rated amout +/- 15%.

Now that your head is spinning, I would suggest trying to up the flow through the chiller and get a contact temp probe to see what the temp is in and out of the chiller and see how that effects things. You may have to get a little bigger pump. I suspect the aquarium pump can only operate with a low pressure (by design) and by adding a bunch of piping and fittings, the available flow goes way down.

Let me know if you have any questions.

Mike

[Charles@AEppelTreow]

The chiller is sized for 1", but everything else is smaller. It's running a little pump from Grainger, not an aquarium pump. I also have a centrifugal pump kicking around that would give a lot higher flow on a chiller loop. If I set up a second loop, I guess I'd try using the pressure post pump to drive the still loop - and just see what I get - or set up a second loop with the little impeller pump running now.

Is my thermodynamics mostly right? That the same equipment will move more heat from 85F water to ambient, than 60F water? (Putting the chiller last in one loop.) ((Ambient is about 60-65F right now))

On the other hand, it works with the 100 gal tank. Starting at 50F, the hearts only runs the tank up to about 55-60F. The tails runs it up to 75F (at the inlet of the product condenser). Still well under flashpoint. The second goal was to have a smaller cold tank. 15 gal was way too small.

If you (or others) are curious: http://sunlightsuppl...r-chillers.aspx

I'm sure the electrical consumption gives it away. And I paid less than list for the 1.5 'HP'. I just double checked the manual. If it's rated for 1300gph, how am I getting away with so much less without the thing freezing up. Must be a curious set of specs.

[MG Thermal Consulting]

I am not sure what you have as far as refrigerant compressor goes, I gave you what a 1/2 HP pulls and that is at 230/1/60 and you said you were running 115/1/60 which would be much greater than 10 amps if it was a 1/2 HP.

How much time does it take the 100 gal tank to heat up?

If you can get close with that 100 gal tank and have a way put put another tank along side it, doubling your recovery, you may have the solution. You would need to run a line between the two tanks towards the bottom of each to "equalize" the levels.

Other than that, if you can reset the chiller outlet set point for 45F then you would have a better differential but it may take longer to get to the set point on the tank.

I have small "rack" type indoor chillers, less than 1.5 HP or you might find sometrhing similar and stagger chiller/tank combo systems if you get to the point where the combination of not enough recovery time doesn't do it for you.