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astig
06-09-2006, 03:55 PM
Hello every body,

Can any one show me the basic calculation of making ice, say 279mm X 559mm X 1295mm, 136kg ice block, 80 pc.

Suction= -15C
Discharge= 35C
Aircooled condenser
Refrigerant= R22
compressor capacity?
eveporator surface area?

Thanks,
astig

Peter_1
06-09-2006, 07:54 PM
Can any one show me the basic calculation of making ice, say 279mm X 559mm X 1295mm, 136kg ice block, 80 pc. Suction= -15C, Discharge= 35C, Aircooled condenser, Refrigerant= R22, compressor capacity?
eveporator surface area?

You forgot the most important one: available time !!

Now, you made already the calculation for the weight, so I will make a rough estimate: 136 x 20 (assuming water is 20C when starting) + 136 x 85 (+/-) + 136 x 0.8 x 5 (assuming freezing to -5C) gives = 14800 kcal or +/- 18 kW + Losses gives +/- 20 to 22 kW.

Evaporator surface, well you have to make a matrix /shape - preferable in stainless steel or aluminum - with the dimensions of the iceblock you want to make.
This matrix must be frozen down to -10C (+/-) with direct expansion coils.
A small hot gas defrost systems to release the blocks out of the shape.
May I ask, is this for ice for ice carving?
If so, the difficulty will be making perfect clear ice with no air bubbles in it.

A colleague of mine is making these ice blocks the whole year for http://www.ijssculptuur.be/ and this is the only thing he's doing :cool:
He has a generator to produce the electricity for his compressors.

astig
06-09-2006, 11:33 PM
Hi peter_1,

The available time is 24 hr, I need to harvest every morning of 40 ice block.

This is for fisherman.

Starting temp@ 28C.

Thanks,
astig

astig
06-09-2006, 11:34 PM
Any more website for block ice making?

US Iceman
07-09-2006, 02:43 AM
A much older method to freeze ice blocks used flooded ammonia pipe coils in a large tank of cold brine.

The ice cans were placed in the tank and then the cans were filled with water. The cold brine was circulated over the pipe coil.

As the ice cans begin to freeze an air tube was placed in the center of the ice cans. Since the water would freeze relatively slowly, the impurities, air bubbles, etc., would tend to collect in the center of the ice block.

Before the air tube would freeze in the center of the ice can, the air tube was removed and the unfrozen water in the center was removed.

Sometimes, this center would be cored out to remove the adjacent particles that might be trapped in the ice. Then clean water would be poured into the center core to freeze.

Nice clean ice...:cool:

Here are a couple of links.
http://home.howstuffworks.com/question205.htm

http://www.ingvar.is/Plants/BlockIce/Pip.JPG

http://www.epsltd.co.uk/blockice1.pdf#search=%22block%20ice%20making%22

Peter_1
07-09-2006, 06:39 AM
Hi peter_1,
The available time is 24 hr, I need to harvest every morning of 40 ice block.

Recalculated it with 28C down to -18C (you need to store it in a freezer at this temerpature afterwards I suppose?) gives theoretically 20 kW, take 24 kW inclsuing heat loss x 40 blocks = +/- 1000 kW /divided by 24 hours = +/- 40 kW, evaporating at -15C = +/- a 30 HP compressor you will need.

Try to avoid the high water temperature entering of 28C. Feed it first through the ground.

What's the purpose of these blocks, this question wasn't answered?

astig
07-09-2006, 02:06 PM
Hi peter,

This is for fisherman.

Thank you for help.

Regards,
Astig

US Iceman
07-09-2006, 02:46 PM
You might also consider the use of a pre-cooler (a small refrigeration system/water chiller) to cool the water from 28C down to 4.4C.

If you can remove the heat from the water at a higher refrigerant evaporating temperature, this is more efficient than allowing the low temperature refrigeration system to cool it.

knighty
07-09-2006, 02:56 PM
Don't really now much about this, but I make dog food and I see a lot of ice making machines in slaughter houses that make crushed ice... would that be any good ?

they make a hell of a lot of it ina pretty short time too :)

normaly you slide a dolav (big plastic tub the size of a fork lif pallet) then it fills it up.... machines are normally about 4foot square on the floor and about 8 foot high.

hope that helps

knighty
15-09-2006, 01:24 AM
p.s.

was looking around the web at some other machines and stumbled onto this...

http://www.alimex-gmbh.com/index.php?kat=gebdetail&lang=E&pid=665

thought it might be of intrest in this thread :)

Peter_1
15-09-2006, 07:14 AM
The reason why they add ice in the meat is to reduce the 'generated heat' while it's cut in the high capacity cutters. Friction of the knife is transformed to heat in the meat.

A better method is use partially frozen meat between the fres meat.

They add and sell in fact water at the price of the meat :D so the ice may cost a little bit, it's well payed.
But' it's needed in the production process.

Same reason why a baker adds cooled water to the paste, when it's knead, the leaven in the bread should warm up and let the past rise already in the kneading machine.