Sciencemadness Discussion Board

Condenser cooling

pHzero - 14-6-2009 at 12:37

I've been trying to make some distilled water, but I got stopped by my mum for using up too much tap water for cooling. So I need a new way to cool my condensers. I'm planning a sort of air-cooling system



The idea is that water is pumped round a closed system, perhaps using one of those drill-powered pumps that I've seen. The hot water goes through some sort of radiator, perhaps an old car radiator, cooled by fans - either desk fans or computer fans.

Can anyone see any problems with this idea? Is there anything I haven't thought of that I need to take in to consideration

hissingnoise - 14-6-2009 at 12:57

If your water-supply is unmetered it might be easier to convince Mum that your water usage isn't a problem. . .
Failing that, your sketch looks OK but corrosion in car radiators can be a problem. . .
A closed system, though, might side-step that!

panziandi - 14-6-2009 at 13:00

Why not have a bucket of water with some ice added. Place a pond pump in there with a tube leading to your condenser inlet, then a tube leading from the condenser outlet back to the bucket. Condenser water is rarely warmed much and rapidly cools to a temperature that is usable again, you can do without the ice for most condensates but for toxic or very volatile/flammable vapours this is recommended. Sacks of ice are dirt cheap and a bucket of water is much better than a gurgling drain :P

DJF90 - 14-6-2009 at 13:04

"Sacks of ice are dirt cheap..."

Where the hell do you buy your ice?? I get mine at sainsburys and its on offer atm for £1/2kg... which is still extortionate :P

pHzero - 14-6-2009 at 13:12

Quote: Originally posted by panziandi  
Why not have a bucket of water with some ice added. Place a pond pump in there with a tube leading to your condenser inlet, then a tube leading from the condenser outlet back to the bucket. Condenser water is rarely warmed much and rapidly cools to a temperature that is usable again, you can do without the ice for most condensates but for toxic or very volatile/flammable vapours this is recommended. Sacks of ice are dirt cheap and a bucket of water is much better than a gurgling drain :P


Hmm, would it cool down enough? I'd imagine that it'd just keep heating up, wouldnt it? And as DJF90 says, ice is pretty expensive. But maybe instead of using ice, I could chuck some liquid propane in the bucket, which would cool it by evaporation? I'm about to get 19kg of propane for £30, so that's about 75p/litre.

hissingnoise, sadly, we are metered :( We used to be on an unmetered supply but then my dad got a meter installed to save money

DJF90 - 14-6-2009 at 13:17

pHzero - dont be an idiot. Why are you buying so much propane?? Other members have already warned you against buying bulk quantities. You think your propane is gonna come in a plastic bottle as a liquid? If so you are sadly mistaken. Water by itself will be fine for most things.

User - 14-6-2009 at 13:19

Cooling water does warm up quite quickly , Its underestimated.
I had a bucket with a pump , the system contained about 25 liters of water and yes after distilling for about 2 hours the water felt hand warm.
I came up with a darn simple solution. I bought a 65 liter cement mixing tub.
This keeps cold for hours. By adding a little bleach the water remains free of organisms.
It's a good system which is running fine for more then a year now.
Another funny thing is that i have a timer switch on the pump, when i go to bed and a setup is still cooling down i set the timer on half an hour or so.

panziandi - 14-6-2009 at 13:21

Quite often I just have a bucket with lets say 10L of water in it (actually perhaps 5L) and I have a pump which pumps that through my condenser and back to the bucket, I can condense most things like that very efficiently. The water cools suffiently travelling back into the bucket and cooling of a small volume of water by the bulk volume of unused water is adequate, for some things I do opt to have a block of ice added to ensure the water in the condenser is very cold. Never had any issues at all.

Yeah ice is a bit pricey (compared to tap water) but you don't NEED it, like I said, cooling by mass-action of unused water is suffienent. I suppose depends how much you are distilling/condensing and over what time period. Try this method before investing in a variety of fans and radiators and time :P

DJF90 - 14-6-2009 at 13:25

I think it would be more important for him to try it before blowing himself up personally... If he's using a heating mantle its risky, but my guess is our little experimenter here uses a bunsen...

kclo4 - 14-6-2009 at 13:32

Perhaps if you need to cool your water to room temperature using the bucket method, you could get a fish air bubbler or something that will pass air into the water to help cool it off?
It probably wouldn't work very well at all, it was just the first thing I thought of so I decided to blurt it out. But the increased surface area from the bubbles would lead to increased evaporation, and cooling.

What would probably work a lot better assuming you need it room temperature is to use a metal bucket. That would conduct the heat better into the cemenet, or whatever it were standing on.

Ozonelabs - 14-6-2009 at 13:35

pHzero- for your own good, don't buy that much propane.

We have no idea how exactly it is that you intend to liquify the propane- surely though, whatever agent you would use to liquify it could just be employed in itself to cool your condenser? With the added bonus that you dont have to deal with large quantities of flammable material.

You have been warned on more than one occasion about your general laboratory practice. If you ignore these warnings, it will surely be not only to your peril, but to the peril of the Amateur science community.

Think before you act.

User - 14-6-2009 at 13:37

I can imagine using a large block ice works nicely, I once even thought of using the pool next to my house.
Oke it would be overkill, funny overkill.
personally i really don't like using open flames, only for small scale tests with test tubes.

Djf90 , do you mean the guy talking about the propane?

pHzero - 14-6-2009 at 13:42

Quote: Originally posted by DJF90  
pHzero - dont be an idiot. Why are you buying so much propane?? Other members have already warned you against buying bulk quantities. You think your propane is gonna come in a plastic bottle as a liquid? If so you are sadly mistaken. Water by itself will be fine for most things.


I've already got through most of a 4.5kg bottle of butane for my bunsen in a couple of months, so I've decided to replace it with a 19kg bottle of propane - that should last me the best part of a year. It comes as a liquid in a steel cylinder and if you hold it upside down, you can pour it out as a liquid, because it auto-refrigerates. I tried this with butane and filled a test tube with it then left it boiling away in the sun. When I went back about 10 minutes later, most of it was still there.

Anyway, back on topic, we have an unused water butt which I think is about 80 litres, I'll try using that. I might try kclo4's bubbler idea - the increased surface area could be useful. Thanks for your input, everyone!

ps, O3labs, I understand how buying some things in bulk can be dangerous, but propane? Calor gas cylinders are made out of thick steel which can withstand huge pressures.

[Edited on 14-6-2009 by pHzero]

watson.fawkes - 14-6-2009 at 13:47

Quote: Originally posted by pHzero  
The idea is that water is pumped round a closed system, perhaps using one of those drill-powered pumps that I've seen. The hot water goes through some sort of radiator, perhaps an old car radiator, cooled by fans - either desk fans or computer fans.

Can anyone see any problems with this idea? Is there anything I haven't thought of that I need to take in to consideration
Such systems are used commonly; for example, every car has one. The issues are engineering ones.

1281371269 - 14-6-2009 at 13:50

I don't see what's wrong with 19Kg propane? It comes in metal containers, 4.5kg, 19kg, 40somethingKg. You can buy a container from a local garage and it's barely more suspicious or dangerous than buying a few litres of petrol for the lawnmower...

hissingnoise - 14-6-2009 at 13:51

pHzero, DJF90 and Ozonelabs are correct---the propane idea is crazy; a highly flammable gas like propane will cause an inferno at the slightest opportunity.
The smallest spark will set it off. . .

pHzero - 14-6-2009 at 13:52

Quote: Originally posted by Mossydie  
I don't see what's wrong with 19Kg propane? It comes in metal containers, 4.5kg, 19kg, 40somethingKg. You can buy a container from a local garage and it's barely more suspicious or dangerous than buying a few litres of petrol for the lawnmower...


Yup, in fact it comes in steel bullets and boils a lot quicker if it did leak/explode, so you could consider it even to be safer. I know plenty of people who use big bottles of propane for camping, but have never managed to kill themselves
Quote: Originally posted by hissingnoise  
pHzero, DJF90 and Ozonelabs are correct---the propane idea is crazy; a highly flammable gas like propane will cause an inferno at the slightest opportunity.
The smallest spark will set it off. . .


I take it you didnt mean to include me in that list? xD
But yeah, now I come to think of it, its pretty damn easy to ignite - that wasn't one of my best ideas.

[Edited on 14-6-2009 by pHzero]

User - 14-6-2009 at 13:53

This gets me thinking, what is the max use able temp for a condenser cooled with water.
I can imagine there would be a point at which the thermo shock would be to great for the glass to handle.
If course this could be slightly avoided by placed the condenser far away from the heat source, where one could use a bridge.

Anyone?

Lambda-Eyde - 14-6-2009 at 13:57

User: That's why one uses air condensers for substances with a BP of ~200*C and higher.

But yes, it is an interesting question.

pHzero - 14-6-2009 at 13:59

Quote: Originally posted by User  
This gets me thinking, what is the max use able temp for a condenser cooled with water.
I can imagine there would be a point at which the thermo shock would be to great for the glass to handle.
If course this could be slightly avoided by placed the condenser far away from the heat source, where one could use a bridge.

Anyone?

Hmm, thats a good question. I'd say at least a few hundred degrees - i poured cold water in a borosilicate beaker of molten sulfur once and it came out fine. But on the other hand, a few days ago, I left a melt of Ag2O to freeze in a borosilicate beaker, just being cooled by the ambient air, and it broke.

[Edited on 14-6-2009 by pHzero]

merrlin - 14-6-2009 at 14:42

If you are doing this outdoors, then the closed loop system you suggest could be augmented with a water mist applied to the radiator. Evaporative cooling would allow a compact radiator and reduced water consumption. You should use enough mist so that the excess water collects and drips off the radiator, preventing mineral buildup. From an energy balance standpoint, the heat removed from your condensate will be largely used to evaporate a similar quantity of water from the radiator surface. Ice would be effective, but the enthalpy of fusion (6.01 kJ/mol) is quite a bit less than the enthalpy of vaporization (40.68 kJ/mol).

DJF90 - 14-6-2009 at 15:43

Its not the fact pHzero is buying 19kg of propane that bothers me. Its his irresponsibility and intended use that does. Butane will stay liquid when you empty a container of compressed (liquid) butane because the bp. of butane is only -0.5C. This is doable just using a salt ice bath. Propane I suspect is another matter, and I have a funny feeling that you'll have trouble getting it out in liquid form (in a usable amount).

Rather than have you blow yourself up with the bunsen, I suggest you invest in a flashback regulator, just in case... 19kg of propane + flame does not sound like much fun. Make sure that its a propane regulator, and that it fits the bottle properly... this isnt something you want to bodge.

And a water cooled condenser should only be used for components boiling below 150C from what I've read... although I've used a liebig with flowing water to distill oil of wintergreen, bpt 220C. I wouldnt do this often though because its bound to cause some stress in the glass which will eventually lead to breakage.

[Edited on 14-6-2009 by DJF90]

pHzero - 14-6-2009 at 15:51

Quote: Originally posted by DJF90  
Its not the fact pHzero is buying 19kg of propane that bothers me. Its his irresponsibility and intended use that does. Butane will stay liquid when you empty a container of compressed (liquid) butane because the bp. of butane is only -0.5C. This is doable just using a salt ice bath. Propane I suspect is another matter, and I have a funny feeling that you'll have trouble getting it out in liquid form (in a usable amount).

Rather than have you blow yourself up with the bunsen, I suggest you invest in a flashback regulator, just in case... 19kg of propane + flame does not sound like much fun. Make sure that its a propane regulator, and that it fits the bottle properly... this isnt something you want to bodge.


I saw it work on TV - it was a program my younger brother was watching where they had to make a beer cooler. They turned a propane bottle upside down and used liquid propane as a coolant. But now I see that it wouldnt really work if i'm using a bunsen nearby. It'd just go up in flames. I've got a suitable regulator, and I think its designed to prevent flashback - if you blow through it backwards, it closes a valve.

entropy51 - 14-6-2009 at 16:44

pHzero, why are you distilling water of all things? I buy distilled water for less than $1 a gallon and I use it for many sensitive analyses without problems.

You can use a pump in a large bucket of water, as has been suggested. When the water starts to get warm, move the condenser outlet hose to an empty bucket and take out most of the water. Dump the warm water, bring back a bucket of cold water and dump that into the bucket with the pump.

Condenser water only needs to be about 20 or 30 degrees cooler than the the boiling point of the distillate. I only use ice water for distilling when the boiling point is less than 80 degrees or so.

There are probably limits on the amounts of flammables your fire code allows to be stored in dwellings. If you have a fire, the fire marshall's report will note that you were in violation of the fire code. Guess what? Your Mum's insurance company will not pay off on the policy!

Personally I am beginning to believe that pHzero is concocting wild tales of dangerous plans just to set us off. Even most kewls have better sense.:P

watson.fawkes - 14-6-2009 at 16:55

Quote: Originally posted by pHzero  
They turned a propane bottle upside down and used liquid propane as a coolant.
Propane is a refrigerant, designated R-290. So of course expanding a liquid refrigerant causes cooling. The problem (danger aside) is that it's a horribly, horribly inefficient use of refrigerant.

pHzero - 14-6-2009 at 17:06

Quote: Originally posted by entropy51  
pHzero, why are you distilling water of all things? I buy distilled water for less than $1 a gallon and I use it for many sensitive analyses without problems.

Sadly, I can't get it that cheap - the cheapest i can find it is £17.50 for 5 litres (ie about $20/gallon
Quote:

You can use a pump in a large bucket of water, as has been suggested. When the water starts to get warm, move the condenser outlet hose to an empty bucket and take out most of the water. Dump the warm water, bring back a bucket of cold water and dump that into the bucket with the pump.

Condenser water only needs to be about 20 or 30 degrees cooler than the the boiling point of the distillate. I only use ice water for distilling when the boiling point is less than 80 degrees or so.

There are probably limits on the amounts of flammables your fire code allows to be stored in dwellings. If you have a fire, the fire marshall's report will note that you were in violation of the fire code. Guess what? Your Mum's insurance company will not pay off on the policy!

Personally I am beginning to believe that pHzero is concocting wild tales of dangerous plans just to set us off. Even most kewls have better sense.:P


Wait, so you're saying I'm trolling? Because my idea which i thought up on the spot turned out not to be so good on closer examination?

[Edited on 15-6-2009 by pHzero]

bfesser - 14-6-2009 at 17:44

Where have you looked? In the United States, grocery stores and pharmacies sell distilled water in gallon jugs for around 99 cents. I'd be surprised if it's unavailable where you live. (By the way, try the real world... not ordering from the internet.)

[Edited on 6/15/09 by bfesser]

pHzero - 14-6-2009 at 17:49

Quote: Originally posted by bfesser  
Where have you looked? In the United States, grocery stores and pharmacies sell distilled water in gallon jugs for around 99 cents. I'd be surprised if it's unavailable where you live. (By the way, try the real world... not ordering from the internet.)

[Edited on 6/15/09 by bfesser]


Well there isn't really anywhere near me that would sell dH2O. There are a couple of chemists but even if they did sell it, I expect their prices would be totally extortionate. I'll check tomorrow but I doubt I'll find anything.

Lambda-Eyde - 14-6-2009 at 22:33

ANY hardware store carries deionized water... And it costs next to nothing.

And pHzero: They're not calling you a troll because of the idea with the propane, they're doing it because during your relatively short time here at SciMad you have shown that you are very irresponsible, you don't follow safety procedures, and you have no respect for chemistry as a hobby.

Heck, you're boiling mercury in your kitchen, storing "sulphuric acid and ferricyanide on your BEDSIDE table" (now a personal favorite of mine), storing 20 liters of methanol in the sun, nitric acid on your lawn, playing with tens of kilos of extremely flammable gases, and your house looks like a meth lab...

I really hope you are trolling, if not, then you'll end up killing someone someday... :( I just hope it won't affect those around you (not that I want to see YOU dead).

DJF90 - 15-6-2009 at 06:56

Lambda-Eyde: I think you sum up exactly how I feel about this chap. pHzero needs to sort alot out before he should even consider continuing to experiment. Deionised water and distilled water are usually acceptably interchangable in the home lab. You can find it at most hardware stores for about £3/5L IIRC, maybe even cheaper. I think there may only be one major brand here in the UK (at least as far as I've seen), in a white bottle, with "De-ionised water" written in blue, and maybe a red line above? (I'll try and find a picture...)

EDIT:
Check this link...
http://www.homebase.co.uk/webapp/wcs/stores/servlet/ProductD...

Some stores will do bigger for cheaper, go and look.

[Edited on 15-6-2009 by DJF90]

grndpndr - 15-6-2009 at 08:46

Must be using water on an industrial scale?Be glad you do not live here the problem would be compounded.Our water comes out of the ground at the well over 130f and depending on location summer tap water can be 110-120.
But my freezer holds Ice trays / liter-2liter bottled ice cubes.
Gravity,tubing and 2 buckets take care of the distilling column
as well as reusing the still cold water.

zed - 19-6-2009 at 16:23

In my neck of the woods, cooling recirculated condenser water is only a problem in the Summertime. During other seasons, diverting the water through an appropriatly shaped "outside" storage tank, coil, or radiator..... would render it quite chilly in just a few minutes.

During the Summer, warm exhaust water can be cooled by passing it through an underground pipe or hose system. The planet Earth is a pretty good "Heat Sink".
A few feet down, soil temps run ~55F year round ( at least, on most of the planet!). Which is the reason, of course, that your condenser water was cool to begin with.

Otherwise, misting the exhaust water in some way, so as to cause evaporation, as by running it through a fountain or forcing it through a spray nozzle or a sprinkler head, will cool the water nicely. Using your pump at the exhaust end, to "suck" water through your condensor, whereafter the pump then forces the exhaust water through a spray nozzle, will prevent mishaps. Of course, the further the mist or spray falls, the greater the evaporation, and subsequent cooling.

That being said, if your actually just need distilled or purified water, there may be better ways to produce it.

If you figured out your cost of fuel to produce one gallon of distilled water, you might find it cheaper to just purchase the water outright.

Solar stills are inexpensive and they can be easily crafted. No fuel costs, ever!

There are also.....filtration, ion exchange, and reverse osmosis systems that work very well.







[Edited on 20-6-2009 by zed]

chemrox - 20-6-2009 at 13:25

@Entropy51- he probably wants to start his home lab explorations with something relatively benign. If this works out maybe he will distill some wine next. I like his drawing and am thinking of trying a similar setup using a power steering fluid radiator. I also like the ice/water bucket circulation method.

woelen - 20-6-2009 at 13:57

I have a distillation setup and I use tap water for cooling. No additional ice needed, just plain tap water. I distilled Br2 with that setup and it works like a charm. The outgoing water indeed is quite warm, it is luke-warm, so the heating of the water is not negigible. But this of course is true because of the very low flow rate.

The amount of water, used by my experiments is very low. I adjust the tap, such that the water just trickles out of it, at a rate of not more than maybe 100 ml per minute. This is sufficient, even for cooling stuff like Br2 (which boils well below 60 C).

At a cost of at most EUR 2 per m3, my distillation experiments only require a very small amount of money. Even I am pessimistic, then my setup takes 10 liters per hour, which is just EUR 0,02 per hour.

veech - 3-12-2009 at 15:25

Hello, I'm new to the forum but thought I would chime in on this older thread.

I built a similar system, using an automotive transmission fluid radiator (~$60) that I bought new at the auto parts store. It even came with high temp hoses and clamps. These come in all sizes so you can find the right one for your application. I blow a regular old small house fan through it for cooling, using a small pump to push glycol up through my 600mm graham condenser, back into a 0.5L collection tank, and into the radiator again. The whole setup cost me around $100 and it runs my distillation setup for hours without the condenser even getting warm to the touch externally. I usually distill at BP ~90C. Plus I can leave it set up in my garage even during winter without worrying about freezing when not in use. Works like a charm and maintenance free-I'm very happy with the results. :)

white rabbit - 3-12-2009 at 22:46

Adding to the chord, I am also a newby to SM

I have also been using a home made water chiller for my condenser cooling. It is constructed from a window ac compressor (5000 Btu) and works well for the smaller condensers, keeping the water at 3-5*C, but has trouble keeping up on the large scale, double cooling condensers. I am constructing another from a 1 ton (12k Btu) unit to handle the larger volume distillations. I have included a picture here of the unit in operation.



Small cooler.JPG - 42kB

grndpndr - 3-12-2009 at 23:52

Doenst anyone own a freezer.Feeze a gallon or several, milk jugs full of frozen water with a recirculating system with pump or just a catch basin to catch and recool the water and let gravity do the
cold water delivery to the condenser.Failing that Idea how about just buying dist water or water treated by reverse osmosis very common here costing $3/5gallons.(akalinity/excessive radon exceeding gov secs.,instead of recitifying the radon issue $$ is being spent on 80yr old water/ sewer system pipes to instal water meters to charge for nonpotable water?
I dont think the energy consumption of distilling water would come close to the purchased distilled/reverse osmosis water,Heating the water to a vapor, cooling the condenser,Time,trouble though in some instances
doing it yourself with improvised equipment is 90% the fun of the lab at least in my eyes.Maybe dist water is his code word for FNA?

MagicJigPipe - 4-12-2009 at 14:36

I don't get what's so bad about 19kg of propane. What is that about 40L? That is a lot but many people have huge 250 gallon (about 1000L) tanks in their front yards. What of it?

But I think it would be ridiculous to let large amounts of propane evaporate into the surrounding air. I mean, surely you weren't even considering that.

If you want something cheap and quick just use a huge bucket with lots of ice from the freezer or a bunch of those cold packs. Depending on the length of the distillation it will work fine. I too have been pondering methods of cooling condenser water continuously. Was it Magpie that built a cooler out of an old AC unit?

white rabbit - 4-12-2009 at 18:38

It's the length of the distillation that is the problem. I have done the ice thing and it is a real pain in the ass when your studying other aspects of the process and then realize that you have to go get more ice. With the cooler and a couple of gallons of water, it's taken care of.




I once had to use 80lbs of ice to cool a flask. Not cheap or easy.

[Edited on 5-12-2009 by white rabbit]

MagicJigPipe - 17-4-2010 at 06:23

To be fair it's probably not cheap to run a 5000 btu compressor either.

I found an old A/C unit the other day and I'm thinking about using it as a chiller. I need to make sure it actually works though.

Skyjumper - 18-4-2010 at 09:34

You could put your bucket of ice water in one of those dorm fridges (the small ones). Safer than dumping propane on a cooler (with a bunsen going right next to it) Also Liquid propane will flash to a vapor at atmospheric pressure and appears white due to moisture condensing from the air. (wiki),

Come to think of it, this kid hasn't posted in a while. Maybe he tried this and found out why you don't have pools of hydrocarbons right near a burner... Or maybe something to do with his making xCN and other nasties at night in his room.

peach - 1-5-2010 at 04:16

Hey! Don't be putting him off distilling water! A lot more DIY chemists need to stop messing around with some of the stuff they are and learn the basics on water. :P

Damm meth addicts blowing up every 4 out of 5 houses with their ether antics. "NO ADDICTS! NO! PUT THE CIGARETTE BACK IN THE PACK! BAD! WHY ARE YOU PLAYING WITH THE LIGHTER?" The police don't even need to bother arresting them, they're always on fire whenever they turn up anyway. Mentally and physically. Or at least they think they are. Got to extinguish your addicts before the cuffs can go on.

Besides, he's probably distilling his own moonshine. You know the routine "So I've got this Al/Hg reduction running on erm.... something"

Anyway, here's an idea I had which is waaaaaaaaaaaaaaaaaaaay easier than any of that ripping radiators or AC units apart stuff;

http://www.sciencemadness.org/talk/viewthread.php?tid=10450&...

Now you need to convince your mom you NEED that freezer from the dump and that it's not using up too much juice. Have you got an exercise bike in the house? Hook it up to that. :D

The best approach to dealing with a woman based problem is to be direct. Go to the dump yourself or with a friend, collect the freezer and set it up in the house while she's out.

I like you piccy, precise, informative, yet stylishly sketched - I particularly enjoy the coil, a difficult element to draw.

[Edited on 1-5-2010 by peach]

peach - 1-5-2010 at 04:32

Oh I see, you might actually be genuinely distilling water.

Bare in mind that not all workups actually NEED distilled water. You can get away with the deionised water for refilling lead acid batteries sometimes. Filtered water also lacks the chlorine that causes so many problems. For other reactions or washups, you can just get ultra lazy and use tap water. If your aqueous phase is already rammed full of byproducts and HCl, the tiny bit of extra chlorine in tap water is swamped by the acid anyway.

Incidentally, if you're on a metered water supply, you may want to consider your moms point about running the coolant straight to waste, since you'll probably have spent a few $$$ on tap water by the time you get 5l of distillate over.

Water also has a fairly high latent heat capacity. Basically, that means it takes quite a lot of energy to boil it and it releases an equally large amount of energy when it cools. That's why it causes such horrible burns. So, whilst the coolant doesn't need to be particularly cold to affect condensation of water vapor, it will warm up quite quickly in a small, sealed, recirculating system. Specially if you're going to be running 5l through it - that's a decent amount even by the standards of the nerds on here.

Saying this, how fast did you have the water flowing? Since water vapor will condense without the coil being super cold, you could have it trickling through the coil. If you had a tap like stream of it at the other end, you're almost certainly overkilling it.

There's a worrying percentage of people in the US who believe distilled water is better for you because it's pure. That's actually incorrect, as the purity means you're not only lacking the trace minerals that may be of use to your body, but the water is more likely to upset the osmotic balance of your body that's been established through millions of years of evolution, drinking pond water.

As for bottled water, har har har. A journal entry recently explained how estrogen like byproducts leak out of commonly encountered plastics. The study specifically looked at bottled water, which had detectable quantities of it stored within. "Drink Volvic, grow a Vulva!". This has also been put forward as an explanation for why girls are continually reaching sexually maturity at an ever decreasing age; exposure.

[Edited on 1-5-2010 by peach]

chief - 1-5-2010 at 05:49

@ peach: Your post above, with the refrigerator, gave me quite some idea:
==> Just inserting into the fridge a 20-liter-thing with some water, then heating the water up to maybe 30 [Cels], and letting the fridge run ...

If the heating rate of the water could be kept high enough, the the stuff wouldn't form ice on the colder surfaces, just condense ...
==> and drop into something, or come out of some hole in the bottom of the fridge ...

This might actually be energetically more efficient than heating the water up to the 100 [Cels] otherwise needed ...
==> The needed vaporizartion-heat is different at any other temperature ...

Also Ethanol might be obtained this way: A fermentation-cell would be within the fridge, regulated to 25 [Cels], which is about the optimum for yast ...
==> The it would be just as easy as filling in sugar with some nutrients every 2 days, and all the while the Ethanol would collect, withdrawn fom the water and thereby not hindering the cell-growth of the yast ... :D

Maybe it even could be "freezed" out of water on the cooling-surfaces within the fridge, by letting the fridge run really cold, so that ice would form, but ethanol would still drop down ..., sort of giving a better separation ... and higher-conc. ethanole ...
==> Any ideas on the energy-efficiency of this as compared to standard-vacuum-destillation or normal destillation ?
==> Industry as well chooses those conditions, which are most energy-efficient ...

===============

... except maybe I forgot above that the inefficiency of refrigerator-cooling would probably eat up any efficiency-advantage of distillation at lower temperatures ...

... but still easier to run a 20-liter setup than to watch flasks boiling to emptieness ...

[Edited on 1-5-2010 by chief]

peach - 1-5-2010 at 07:48

Quote: Originally posted by chief  
@ peach: Your post above, with the refrigerator, gave me quite some idea:
==> Just inserting into the fridge a 20-liter-thing with some water, then heating the water up to maybe 30 [Cels], and letting the fridge run ...

If the heating rate of the water could be kept high enough, the the stuff wouldn't form ice on the colder surfaces, just condense ...
==> and drop into something, or come out of some hole in the bottom of the fridge ...

This might actually be energetically more efficient than heating the water up to the 100 [Cels] otherwise needed ...
==> The needed vaporizartion-heat is different at any other temperature ...

Also Ethanol might be obtained this way: A fermentation-cell would be within the fridge, regulated to 25 [Cels], which is about the optimum for yast ...
==> The it would be just as easy as filling in sugar with some nutrients every 2 days, and all the while the Ethanol would collect, withdrawn fom the water and thereby not hindering the cell-growth of the yast ... :D

Maybe it even could be "freezed" out of water on the cooling-surfaces within the fridge, by letting the fridge run really cold, so that ice would form, but ethanol would still drop down ..., sort of giving a better separation ... and higher-conc. ethanole ...
==> Any ideas on the energy-efficiency of this as compared to standard-vacuum-destillation or normal destillation ?
==> Industry as well chooses those conditions, which are most energy-efficient ...

===============

... except maybe I forgot above that the inefficiency of refrigerator-cooling would probably eat up any efficiency-advantage of distillation at lower temperatures ...

... but still easier to run a 20-liter setup than to watch flasks boiling to emptieness ...

[Edited on 1-5-2010 by chief]


THERE IS SOME CHEMISTRY INVOLVED IN THIS TO DO WITH PYRIDINES TOWARDS THE END, SKIP AHEAD IF YOU CANT BE BOTHERED WITH MY RAMBLING AND THEN READ BACK IF INTERESTED. SKIP TO "THE CHEMISTRY STARTS HERE"

Now you're thinking in the peachy manner; which is worrying. :P Ask you doctor for an appointment.

I doubt your method, which is seriously cheeky, would actually be far off the glassware variations on distillation in terms of efficiency. In fact, you're correct that it may be more efficient, since this way involves a lot of insulation and lower temperature gradients to loose heat through. It'd just take longer, but who cares with such simplicity right? Just chuck it in, walk away and let it go for a week or two.

I've seen your idea somewhere else, on the Turbo Distillers homebrew moonshine pages. There, they build a super simple pot still which is just a plastic bucket inside a slightly bigger plastic bucket, with a lid on the second. The foul homebrew is place in the smaller pot with an immersion heater and gently cooked. The alcohol vapors cool on the outer bucket and run down the walls. Not as fast as a water cooled condenser, but dirt cheap, virtually impossible to brake and it works. I'm constantly impressed by the inventiveness and dedication of the addicts out there; including the smack addicts who spend all day rooting through bins for $20 worth of junk, poor guys.

The fridge would just accelerate the process. The only problem with continually drawing it off would be defined by how quickly the vapor actually left the mother liquor at a temperature where the yeast was still able to function. You can't have your yeast too hot. I think the turbo yeast performed best at something like 27C, but I have a solution to that problem, which I'll discuss..... NOW!

Bare in mind that a freezer typically has an extremely good seal and essentially only has one open surface, the rest is molded. I'd be willing to bet you could get a fridge to be more airtight than a none greased up glassware setup. You could probably make things easier on your yeast by exposing the entire interior of the fridge to a vacuum. Thereby causing the alcohol to evaporate at a lower temperature. And as it so happens, I have also just made a long post about how to obtain 80mbar vacuums free of charge, m'ere;

http://www.sciencemadness.org/talk/viewthread.php?tid=13581#...

Note that the last bit on the disadvantages wouldn't apply for such a dirty, bulk distillation.

And also, this is getting funnier, the water / ethanol azeotrope is broken under vacuum, so maybe there's some potential there for ending up with a fridge full of absolute alcohol. Cue Homer Simpsonesque exploding garage.

What is a problem with the fridge pump method is that, from memory, you need a pressure of something more like 60mbar to break the azeotrope, which the compressors I've seen won't do. But you can always clean up your alcohol afterwards. What's important is that you get the evaporation occurring at a decent rate at a temperature the yeast will be happy with, and I'm guessing 80 - 120mbar will do fine. I've been up and typing all night, so I'm not running the sigma-aldrich pressure / temperature curve calculator thingy for that now. I can already guess it'll be low though.

Not sure how you'd stop the alcohol vapor going for the pump, as it's not a standard condenser setup where you have the condense blocking the path of the vapor. But, provided leakage rates where low and given that the alcohol will be coming off very slowly, it might form more of a plume around the bin. So you could stick the vacuum port right down at the base and the vapors would then have to plume out and down the walls to get there.

I place the blame for my fascination with fridges with my DIY expert neighbor, who once pulled the compressor out of one we were chucking out and made us a fancy airbrush compressor with it.

[Peach's pc has crashed, linux... wtf? And an immediate trip to get some beer is accomplished whist it reboots. Peach is itching for a smoke, where is nicoderm when you need him? I could give him a lick. Peach has been up all night on sci-mad after driving parents to holidays]

Some fridges / freezers have a moisture collection point for collecting waste water dripping down the walls from condensation. If yours featured one, you could just hook some tubing up to it and run the alcohol off to a big flask. Then any explosion would be more likely to just be a loud bang as opposed to a major fire hazard, since there'd only be a tiny amount of vapor to ignite. You could also scale up the size of the fermentation bin since all the alcohol would be leaving the fridge.

A fridge would probably be better than a freezer. You'd want to keep your temperatures, the warmth of the fermentation and coolness of the walls, at just the points they need to be. If the walls are massively cooler than they need to be, it'll suck heat energy from the fermentation and vice versa. Just cool enough to condense the alcohol and keep the fermentation ticking over would be great. Even better, fridges usually have a thermostat built in, as do fish immersion heaters, so you could easily tweak the settings to perfection.

I love this idea, it's wacky to the max! Get that for some 80's chat.

I've messed around with stupid sized fermentations at home before - mainly just for fun. I bought a 210 liter shipping drum for $20 - formly used to internationally ship olives; yummy! It was a beauty, it had a big screw on collar that pinned the lid in place and the plastic it was made out of was so tough I could kick it around the warehouse floor and barely scratch it. It looked like something out of half life.

I'd also bought... :P 100lbs of confectionary sugar from a bakery supplier, stolen a fish tank immersion heater from my crack loving, underage sex having boss and bought some Turbo Distillers yeast; guaranteed to yield something silly like 18-21% distillation ready product in three days.

Before starting the big tank, I'd had a 10l flask cooking with some of the yeast to get the culture rolling and establish the microbes dominance, which'd help inoculate the next mass up, a 20 fold increase in volume.

I added around 25lbs of the sugar to the tank (full of water) and dropped the immersion heater in there. I used a full tank of water and only half the full sugar volume because I knew this girl was going to get seriously turned on and the yeast could kill it's self from thermal shock once it got rolling.

Once I had it up to 50lbs of sugar, I came back the next day and the thing was fizzing like a shaken bottle of coke, the bitch was going critical! :D The yeast had active carbon mixed in with it to soak up the fusile oils, so the fermentation was black. It looked like some evil monster was living in there.

WHY BOTHER PEACH, WHY BOTHER?

Firstly, it was funny. I've done a huge amount of work with shrooms and other bits of nature and really appreciate scaling up and innoculation. I'd been reading a ton of old papers on ergotamine cultures in bioreactors, so inoculation and mass fermentation was on my mind. This was a great way to play around with it hands on, specially as yeast will dominate just about all over bits of life that try to get in it's way once it's up and running. I had a better appreciate for this kind of thing than my tutor at university who had made a big error in his journal entry (trying to sterilize a soil sample using a standard 15 minute autoclave cycle, noob).

Secondly, I was a student at the time and when the harder drugs ran out, I could scoop a pint of this creature out of the barrel and that'd be me sorted for bedtime.

Thirdly,

THE CHEMISTRY STARTS HERE

if you like pyridines, you'll almost certainly have seen the one pot Hantzsch pyridine synthesis.

One of the key ingredients, if my abused memory is serving me right, is a keto-ester.

If you take ethanol, and split the azeotrope with vaccum distillation, you can catalytically oxidize it to the ?acetate? over the beautifully simply copper method. There's a ton of patents and a memo about an industrial plant using it to produce acetate from ethanol derived from bio feedstock. Most of the time the copper is precipitated onto a zeolite, is it ZS-10 (can't remember)? The specific pore size gives it a huge bump up in activity. Zeolites are weird little things.

You can then take that and combine it with some of your dry alcohol in the presence of some concentrated battery acid to get the ester.

From there, assembling the pyridine I think requires some methanol and K manganate. The latter I think is involved in heroin production, but I managed to find normal places to buy it from in bulk; not lab suppliers, but I won't mention the precise sources, since heroin is a horrible thing to happen to someone.

I ran out of patience and never got round to trying it, but the implications if it worked would have been amazing. Pyridine is incredibly useful for things like demethylation. You can also use the synthesis for creating things like the dicarboxy nicotinic acid used by Hendrickson and Wang.

Yep, I know you can buy poisoned ethanol, acetate or ester, or go from niacin, but this was is darn funny! And if you happen to need a few hundred liters of pyridine or a derivative, maybe this might be a way to get there.

There ends my story of alcohol. Feel free to link to it or copy and paste it to related threads. I know it's entirely off topic to the OP's question, but I couldn't resist it, Chief enticed me; blame him. ;) It might be entirely off the mark, but it seems feasible and it's chemistry you can throw into a huge bin and ignore.

[Edited on 1-5-2010 by peach]

white rabbit - 26-5-2010 at 14:51

Quote: Originally posted by MagicJigPipe  
To be fair it's probably not cheap to run a 5000 btu compressor either.

I found an old A/C unit the other day and I'm thinking about using it as a chiller. I need to make sure it actually works though.




The 5k btu chiller costs about 15 cents an hour to run. A 7 lb bag of ice is $2.20

mr.crow - 26-5-2010 at 16:56

Oh hey White Rabbit, I look forward to the next youtube video! What else can be made on an enormous scale?

on topic:

My friend dumped snow into the cooling water for distillation, good ol canadian winter. Tap water would work just as well and if the flow rate is slow enough it won't waste water. We had the water aspirator on full blast all day... whoops.

white rabbit - 26-5-2010 at 17:29

Hey there mr.crow,
Here the tap water isn't very cold and it ain't cheap either. This is why I made the cooler. I use a diaphragm vacuum pump instead of an aspirator for distillations and filtering. It handles vapors really well but only gets down to 10mm.

azo - 26-5-2010 at 18:26

why in the hell would you want to go to that mutch trouble to cool a condenser , doing this Ewould tell you that the condenser is not efficent enough why not just buy a double surface condenser or a duel coil graham condenser and just connect it to the tap ! my duel coil graham condenser has never used no more than half of the condenser no mater what i have used it for .


GO MULTI COIL GRAHAM CONDENSERS:P


man invented machinery to make thing esier not harder.

white rabbit - 26-5-2010 at 19:50

Quote: Originally posted by azo  
why in the hell would you want to go to that mutch trouble to cool a condenser , doing this Ewould tell you that the condenser is not efficent enough why not just buy a double surface condenser or a duel coil graham condenser and just connect it to the tap ! my duel coil graham condenser has never used no more than half of the condenser no mater what i have used it for .


GO MULTI COIL GRAHAM CONDENSERS:P


man invented machinery to make thing esier not harder.



I have virtually every style of condenser, however, I am unaware any deul (sic) coil graham condenser. I do have jacketed cool coil and jacketed dimroth condensers. All that said, the efficiency of the condenser is not in question. It is simply the waste of water and relatively warm temp of the tap water. When distilling some solvents under vacuum,DCM for example, I prefer to have the condenser a bit colder than tap water. Some reflux times are also 7 hours+ and I don't want to run the tap that long either.

Could you post a pic of this "multi-coil graham" condenser? (I am assuming you mean the double coil condenser similar to those used on the rotovap.)

condenser

azo - 26-5-2010 at 23:08

Here is a picture of my davies twin suface condenser will post my twin coil graham condenser soon using it at the moment.

overal lenght 680mm surface area 1400cm2
regards azo

100527-165709.jpg - 67kB

[Edited on 27-5-2010 by azo]

white rabbit - 27-5-2010 at 15:44

Here is a jacketed Dimroth style condenser. The Dimroth coil is 8mm tubing and the tube down the center of the coil is 35mm in dia. The diameter of the outer jacket is 98.6mm and it is 640mm in length. The bottom joint is 45/50 and the top joint is 29/42. I have it pictured near the 2 liter bottle for comparison. The reaction vessel on the left is 3 liters.

Monster condenser S.JPG - 73kB


Here it is on a 50 liter flask. The addition funnel is 2 liters.
50 liter S.JPG - 70kB

Chainhit222 - 27-5-2010 at 15:58

Are you the person on youtube who made the chloroform and ether distillation videos? And is that in your house?

[Edited on 27-5-2010 by Chainhit222]

white rabbit - 27-5-2010 at 16:20

Maybe :}

Chainhit222 - 27-5-2010 at 16:41

yeah im sure the shelf is the same
I really like that song you have in
http://www.youtube.com/watch?v=CnjJMjnxPSk&feature=relat...

[Edited on 28-5-2010 by Chainhit222]

white rabbit - 27-5-2010 at 17:17

Yeah,I believe its called "number 2"-009 sound system.

Btw,it's M1 property,not R1.

undead_alchemist - 28-5-2010 at 12:04

The refrigeration system gives him away.. lol
Quote: Originally posted by Chainhit222  
Are you the person on youtube who made the chloroform and ether distillation videos? And is that in your house?

[Edited on 27-5-2010 by Chainhit222]

MagicJigPipe - 3-6-2010 at 20:57

I wish I was a millionaire, too.

Imagine how much something like that would cost straight from the catalog.

azo - 3-6-2010 at 23:13

you don't have to have lots of money! do what i do buy it from a glass blower that manufactures labortory glassware.
when you buy from resellers they wack the price on just think if it goes through two or three sets of hands

regards azo.

watson.fawkes - 4-6-2010 at 06:01

Quote: Originally posted by azo  
do what i do buy it from a glass blower that manufactures labortory glassware.
The ASGS (American Scientific Glassblowing Society) publishes a list of their members by region: ASGS Find a Glassblower. It is, I believe, an opt-in list, so there shouldn't be a problem about cold calling.

There's a similar British society. I don't know if there's one or not for Europe.

white rabbit - 4-6-2010 at 13:58

I got most of my glassware on ebay. The large condenser retails for $1100 I got it for $250

Mildronate - 5-6-2010 at 07:57

My glasblower cant make 50 liter flask :D

[Edited on 5-6-2010 by Mildronate]

Jimmymajesty - 8-6-2010 at 12:57

Hey! Nice piece of glasswares upthread:)

For simple distillation e.g butyl acetate I use a bucket of water.
For more cold intense applications e.g. pyrolysis of acetone I use an ice cube maker, hacked to cool continously:) the recirk. is done by a small circulating pump, ~30w.
For vigorous reactons, eg nitrosation, I use liquid butane, computer duster spray upside down..;)

white rabbit - 8-6-2010 at 21:34

Thanks.
I have recently modified the design of my water cooler and it's a great improvement over the first design. The new evap coil is 18 feet of 5/16 inch copper tubing sleeved with 5/8 inch poly tubing in which the water is circulated. This design was cheaper and easier to make, also much more efficient.



Cooler modified.JPG - 74kB

Jimmymajesty - 9-6-2010 at 12:26

This cooler rig of yours seems pretty cool:)

I also planned to modify a window air conditioner, namely I wanted to replace the evaporator to a long copper coil, but I was told that if I had tinkered the setup, the calculated flow rates, residence time of the gases, pressure in the evaporator, buddha-knows-what, would differ from the factory adjusted values, so I would only fuck up the air conditoner..

Anyway I would not use plastic tube for that purpose, as it shrinks a lot (source of leaks) and becomes brittle at certain temps, also the frosen water can clog the tube. just make a couple of circles out of copper tubing and immerse it into a thermally insulated bucket of water.

white rabbit - 9-6-2010 at 15:14

I've tried the coil in a bucket and it doesn't work as well. Modifications to window units are not a problem. The system is charged by temp/pressure and it has a low pressure switch which prevents the evap coil from freezing up. I can very easily adjust the water temp from 32* and up.

mr.crow - 11-6-2010 at 18:52

Cool I love the makeshift heat exchanger

mnick12 - 8-7-2010 at 14:15

I am currently working on a cooler for my condenser that should be able to reach sub-zero temperatures. It going to be based on a few thermoelectric coolers AKA Peltier modules. It is going to consist of a insulated reservoir containing a small amount of propylene glycol based antifreeze as the coolant. The coolant will be pumped into a water block on the cold side of the cooler, while the hot side will have a good heat sink for maximum efficiency. I will have two or three of these in a row and the cooled glycol will go directly to my condenser and the used glycol will be led back into the reservoir for re-cooling. All the parts are fairly cheap, the most expensive piece are the water blocks. And this should only cost me a few cents an hr to run. The key here is not to have to much coolant.

Stay tuned for when the coolers get here, once finished I will post some pictures.

kabloona - 8-7-2010 at 22:08

using 5 or 6 sealed blue ice in a camping style ice chest with equal amount in the freezer works well, they have to be exchanged about every 12 hrs.

densest - 9-7-2010 at 08:00

@mnick12 - have you checked out the power in vs heat pumped curves for thermoelectric modules? It might be a surprise... a typical module consumes 20W while pumping 13W across a 30C temperature differential. Cascading them doesn't help, really, either, except to achieve higher delta-T than a single module can.

They're useful where small size, mechanical simplicity, and especially quick and accurate temperature control are important. A rule-of-thumb I've heard is to consider a mechanical refrigerator if you need to pump more than 50W or to achieve more than 50C temperature differential.

See http://www.tellurex.com/technology/design-manual.php
Quote:

The Thermoelectric "Sweet Spot"
Ninety percent of all practical applications for thermoelectric technology fall within a very narrow range of operating conditions.

1. Temperature differential (Delta T) between 30°C and 50°C
2. Thermoelectric module current draw (l) between 70% and 80% of IMAX, and
3. Co-efficient of performance (COP) between 0.25 and 0.4.


The COP is the ratio of heat pumped to power input so that means 2.5 to 4X power in to heat pumped! A mechanical refrigerator can have a COP as high as 10 (pump 10X as much heat as power in!) - no, you can't get perpetual motion :P

Stirling cycle heat pumps look really (ahem) cool... expensive, though. Any company whose website doesn't have a single price number on it probably charges cubic money. The stirling coolers are best from -50C down to 60K or so. Oh well, when they show up on labx or ebay at salvage prices, I'll get one.



[Edited on 9-7-2010 by densest]

Contrabasso - 9-7-2010 at 10:24

Peltier modules usually work well in situations that can't accept a refrigeration cooler, ie it's too small, They are also used to move heat where there is a huge cold sink to get rid of the heat, especially in avionics where the outside air is well below zeroC and moving very fast!

The usefulness of a peltier module can be determined by the uselessness of the usual picnic drinks cooler

peach - 14-7-2010 at 10:39

You're making this far too complicated for regular distillations.

Get a cool box and save up lots of fizzy drinks bottles. Fill them with water, throw them in the freezer. Drop a little submersible pump into the cool box and add some hoses. I used a tiny Hozelock garden fountain pump I found in the garage, and screwed / siliconed a brass hose barb onto the outlet. You can get similar pumps for literally $5-15 dollars.

When it's time to distill, let the cold tap run for a minute to get the cool water though and then fill the cooler and hook it up to the condenser. If you're distilling low BP's, particularly under vacuum, throw in your plastic bottles. You can use cold packs if you want, but plastic bottles work fine and are essentially free. If you pack the cooler with bottles and have just enough water to surround them, it'll probably still have ice in it the next day.

I run B24 glass and liters through mine and it'll take hours and hours for the condenser to ever get much above 0C, which is fine for things like DCM. For the majority of distillations, you won't even need the bottles of ice. Combined with a short coil condenser, 99% of your solvent will be liquid as soon as it touches the coil, let alone near the exit. I can run the cool box up towards 6 hours, and it'll be cold enough there'll be water dripping off the condenser hoses.

I believe the earlier funnies about double coil grahams condensers are because a grahams is usually a single coil surrounded by water. Multicoils are the other way around and are called coil / reflux / Dimroth condensers. A Dimroth is just a coil condenser, but the return at the end of the coil goes back up and comes out back up at the top, near where the water goes in / out.

That is some nice gear White Rabbit! Congradulations! :D

I hope you washed that DCM before distilling it, it looks like it's full of polymer shit. You shouldn't be subjecting such nice gear to that muck.

A similar tune to White Rabbit's, featuring the crazy hula hoop girl ---> follow the link 'Why every guy should buy his girlfriend a real hula hoop' for the dirtier version

That tune also sounds a little like Please (don't) Stop Me, by Planet Funk

[Edited on 15-7-2010 by peach]

white rabbit - 14-7-2010 at 18:08

Hey thanks, Peach.

That polymer $hit seems to be highly soluble in water and cleaned up nicely.


Btw, thanks for the links! ( I didn't find anything dirty about it) It was beautiful!

mnick12 - 16-7-2010 at 23:58

Well the peltiers came a few days ago they are neet little things, but I have not had to much time to mess around with them. Also I am thinking that I may just use them to make a cloud chamber or a soda chiller instead of a condenser cooler. There are loads of fun projects you can do with these little things,

uchiacon - 22-9-2010 at 02:49

hey guys, why not just run your condenser water through a metal pipe coil inside a small fridge?

Couldn't you get a flat coil of copper or aluminum pipe, cut two holes through the sides of it, and have the coil right at the back?
With one of those really small fridges,it'd be able to handle a decent amount of heat right?

ScienceSquirrel - 22-9-2010 at 03:34

I make beer on a 10 gallon (45 litre scale) and after boiling the sweet liquor with the hops it has to be cooled quickly to get a hot break that precipitates out the proteins to leave a clear liquor ready for fermentation.
I use a 25 litre brewing bucket and a small garden pump that pumps the water through a submerged soft copper coil in the hot liquor tank. I cool the cold liquor tank by using giant ice cubes made by filling plastic shoe storage boxes with water and freezing them down in my deep freeze. I tried plastic drink bottles like Peach but the heat transfer due to the insulating effect of the plastic was too slow. I have to use 15 - 20kg of ice per batch.