Fridges and dry-ice

[Guest]

Now on a few posts I have noticed the growing number of people fitting fridges .... to be sure - I wish I had the boat suitable for this !!! size and facility I mean !

Now in my lab - we produce dry-ice from gas supplied to a small block unit .... normal temp of resulting block is -75 C ... now a small unit fitted in a boat to the cool-box would only have to produce a very small block at intervals to provide fantastic cooling the beer possibilities ..... any engineers out there who fancy a go ..... the actual gear to do it is reasonably simple and not so big etc. ..........

<hr width=100% size=1>Nigel ...
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[Fin]

Never mind the beer think of the G&T! Plus what about a bit of smoke when you suddenly realise that you're over the line!!

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[BrendanS]

now there's an idea. I won't tell you what I used to get up to with dry ice in my scientific days.

What's required? We used to get huge quantities of the stuff when we had deliveries, so never had any need to make it

<hr width=100% size=1>There is no such thing as "fun for the whole family."

 

[Guest]

Sorry .... pm first !! I wouldn't want to lose my idea !!


<hr width=100% size=1>Nigel ...
So WHAT does the EU really stand for ????/forums/images/icons/cool.gif<P ID="edit"><FONT SIZE=-1>Edited by nigel_luther on 09/01/2004 20:29 (server time).</FONT></P>

 

[rich]

CAUTION
Caution: Solid Carbon Dioxide (Dry Ice) is -109.3 degrees Fahrenheit. (-73.5 degrees Celcius).
DRY ICE IS A SKIN AND EYE IRRITANT. USE GLOVES TO HANDLE.

DRY ICE IS HARMFUL IF EATEN OR SWALLOWED.

Avoid contact with skin, mouth, eyes, and clothing. May cause severe frostbite or burns. If eaten or frostbite occurs, seek medical help immediately.

DRY ICE MAKES CARBON DIOXIDE GAS AS IT SUBLIMATES (MELTS). DO NOT PLACE DRY ICE IN AIR TIGHT CONTAINERS AS THEY MAY EXPLODE. ONLY USE DRY ICE IN OPEN OR WELL VENITLATED AREAS, OTHERWISE A LACK OF OXYGEN (SUFFOCATION) CAN OCCUR CAUSING SERIOUS INJURY OR DEATH.

UNLESS THEREIS ADULT SUPERVISION KEEP OUT OF REACH OF CHILDREN.

INTENTIONAL MISUSE OF DRY ICE MAY BE HARMFUL OR FATAL.


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[BrendanS]

Strewth,it's not that bad. Yes, needs to be handled carefully, but you're hardly going to be handing out handlefulls of the stuff for kids to eat. Anyway, such a system doesn't need to actually produce dry ice, just chill the block.

<hr width=100% size=1>There is no such thing as "fun for the whole family."

 

[rich]

I just tried to find out how to make it, and found that imfo.

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[Guest]

Blimey ---- he took me seriously !!

The dangers not only of gaseous CO2 but also the extreme cold temperatures attained would put this out of average persons use.
The GRP if not suitably protected would suffer serious damage probably to failure as the resin cracks under the thermal pressure.
The Beer can if cooled suficiently would destroy the human lips and surrounding tisuue causing serous frost-bite

Shoud I go on .....

<hr width=100% size=1>Nigel ...
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[Guest]

Thanks Brendan

As you say full cooling and ice making is not actually called for .... we would look for a temp of about -1 down to maybe -5 C That would be more than enough for good 'water based ice for drinks and quick cooling of the white wine and beer etc. It would provide 'freezer' capability for the boat at no electrical power use etc. etc.

A metered button system for dispensing the gas to the block could be made so that no more than that necessary could be dispensed.

etc.

<hr width=100% size=1>Nigel ...
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[Guest]

MSDS .....

Material Safety Data Sheets .... if you read any of them they all make you wish you never started .... look at a MSDS for Gasoline or Diesel .... and you'll wish you never put it near your boat ....


<hr width=100% size=1>Nigel ...
So WHAT does the EU really stand for ????/forums/images/icons/cool.gif

 

[BrendanS]

Unless you've handled this stuff, make it with care. I've used this, liquid nitrogen, ultra low freezers and even radioactives. It's not dangerous with care, but you really do need care.

<hr width=100% size=1>There is no such thing as "fun for the whole family."

 

[rich]

Re: Blimey ---- he took me seriously !!

The idea got me thinking,i have just purchased a compresser and cold plate.

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[Guest]

Well - you don\'t need my dry-ice then nm

&

<hr width=100% size=1>Nigel ...
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[Dave99]

Dry Ice is not that dangerous. I got the book 'Caring for you crew' (i think thats what the title was) ...any way on long ocean trips they used part dryice and part normal ice in their ice box.

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[VicS]

Re: Expanding the idea

It's an interesting idea but you don't actually need to go to the point of producing dry ice. If you had a CO2 cylinder with provision to draw off the liquid ie a dip tube to the bottom, and the liquid then allowed to expand and evaporate in the same way as the compressed refrigerant does in a normal fridge then you would obtain the cooling you are looking for. Then let the CO2 gas produced vent safely outside. A small control system would be required, unless you want to do it manually, but beyond that no power consumption. The practicality of the idea depends on how much CO2 you would need to store. As it was your idea I'll let you do the maths as my therodynamics never were that good but to get you started the heat of vaporisation at 0deg C is approx 55 g-cals/g. That's actually a bit more than most fluorocarbon refrigerants but a lot less than ammonia, another common refrigerant, at 302 g-cals/g. So the idea would work better with ammonia but venting the vapour would be more of a problem.

<hr width=100% size=1><font color=purple>Ne te confundant illegitimi.</font color=purple>

 

[andyball]

you didn't make dry ice bombs too?

Much more careful with liquid oxygen ,though !!

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[bedouin]

If you want really cold you've got to go for liquid helium

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[BrendanS]

Re: Expanding the idea

Think you'll find that Nigel and I have already said that, though we did a lot of it by pm. So not sure which bits on forum and which off forum

<hr width=100% size=1>There is no such thing as "fun for the whole family."

 

[BrendanS]

I deny all responsibility for all the sub zero experiments we tried. and there were many of them

<hr width=100% size=1>There is no such thing as "fun for the whole family."

 

[BrendanS]

all I would add is, don't knock the valve head off any high pressure cylinder.

<hr width=100% size=1>There is no such thing as "fun for the whole family."