Commercial Ice Block Heatload Calculation

[JohnTan]

Hello,

Can anyone suggest a working example to calculate capacity for
appropriate compressor for a ice plant?

I have someone asking me about making ice blocks for a small
plant with the following given information:-

water source temp: 95 deg F
Ice blocks: 55 lbs. per ice block, 2750 lbs. (or 50 blocks) of
ice blocks within 20 hours.

I need rough guidelines or working example to obtain the
estimated heatload for the compressor.

I lost one of the old ice blocks sizing manual from Bitzer
compressor manufacturer years back :-)

Cheers.
John Tan

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[Sonofdawra]

>Can anyone suggest a working example to calculate capacity for
>appropriate compressor for a ice plant?
>

Takes 1 Btu to cool 1 pound of water 1 degree F. 144 Btu per pound to freeze
32 degree F water to 32 degree ice. 0.5 Btu to cool 1 pound of ice 1 degree F.

95 -32 = 63 degree temp drop to 32 degrees for the water.

[ (2750 x 63) + (2750 x 144) ] / 20

Seems like that should begin to approximate the situation.

Have a nice day, Ron

[bill]

In article <049173ff...@usw-ex0105-034.remarq.com>, JohnTan
<johntan...@nettaxi.com.invalid> wrote:

> Hello,

>
> Can anyone suggest a working example to calculate capacity for
> appropriate compressor for a ice plant?
>

> I have someone asking me about making ice blocks for a small
> plant with the following given information:-
>
> water source temp: 95 deg F
> Ice blocks: 55 lbs. per ice block, 2750 lbs. (or 50 blocks) of
> ice blocks within 20 hours.
>
> I need rough guidelines or working example to obtain the
> estimated heatload for the compressor.
>
> I lost one of the old ice blocks sizing manual from Bitzer
> compressor manufacturer years back :-)
>
> Cheers.
> John Tan
>

95 -32 water=63 difference to reduce water to freezing
2750 x 63 = 173250 btu to reduce water to freezing
2750 water lbs x 144 btu = 396000 btu to turn the water to ice
173250 + 396000 = 569250 btu needed to freeze 2750 lb of ice
569250 / 20 hrs = 28462.5 btuh
28462.5 /12000 = 2.37 tons

-bill

[Rich]

You AC guys forget ice insulates. If you design your system strictly by
btu, latent and specific heat it will freeze, but not in the time
required. I make a lot of flake ice, but not blocks, so can't give you
any specifics. This might start you thinking:
Ice at 14dF (-10C) has a k value of 1.35. For max efficiency limit the
thickness of the ice. Try freezing from the center and the sides.Most
large commercial machines are flooded evap.

Richard Ferry

JohnTan wrote:

> Hello,
>
> Can anyone suggest a working example to calculate capacity for
> appropriate compressor for a ice plant?
>
> I have someone asking me about making ice blocks for a small
> plant with the following given information:-
>
> water source temp: 95 deg F
> Ice blocks: 55 lbs. per ice block, 2750 lbs. (or 50 blocks) of
> ice blocks within 20 hours.
>
> I need rough guidelines or working example to obtain the
> estimated heatload for the compressor.
>
> I lost one of the old ice blocks sizing manual from Bitzer
> compressor manufacturer years back :-)
>
> Cheers.
> John Tan
>