Dear all:
Here is an alternative.
And may I use SI units?
Assuming no heat losses, and ice temp is 0 C (normal ice temp); and that
the final temp of fish sought is not lower than 0 C.
Heat given off by the fish = Heat absorbed by melting ice
mf cp (t1 - 0) = mi Lf
where
mf is the mass of fish in kg;
cp is the specific heat of fish; I agree with parameters stated earlier
but we could simplify further and make it 1(unity); kcal/kg-C
t1 is the initial temp of the fish; C
Lf is the latent heat of fusion of water; 80 kcal/kg; lastly
m1 is the amount of ice; kg, (which is the one sought for), and could
easily be calculated.
This calculation is a fast estimate of the base ice requirements.. We
normally use more than this value to compensate for transport heat
losses and other losses/factors.
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Another alternative is to use a "rule of thumb"; the ratio of 1 part
ice to 2 parts fish. This seems to also satisfy the aforementioned
calculations, and also compensating for the other heat lossess.
Then of course, this assumes that the initial fish temp to be at normal
water temp.; which is around 25 C.
I hope this helps.
Best regards,
Jose
-- ----------------------- Jose P. Peralta, Ph. D. Professor/Food Engineer Inst. of Fish Processing Technology College of Fisheries, Univ of the Phil Visayas 5023 Miag-ao, Iloilo, Philippines Tel (63 33) 315 8289 FX (63 33) 315 8289, 315 8353 Cell (0917) 302 1282 EMail jperalta@loilo.net ------------------------
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