Thermodynamics question I'm stuck on :(

Question

Any advice on how to solve this would be appreciated... for some reason I just can't figure this out. I've been going back to this problem for weeks lol. Thank you for your help!

A refrigeration system is being designed to cool eggs (ρ = 67.4 lbm/ft^3 and Cp = .80 Btu/lbm * F) with an average mass of .14 lbm from an initial temperature of 90F to a final average temp of 50 F by air at 34 F at a rate of 10,000 eggs per hour.

a) find the rate of heat removal from the eggs in Btu/h

B) find the required volume flow rate of air, in ft^3/h, if the temp rise of air is not to exceed 10F

Answer 1

Well, the average mass of 0.14lbm * 10,000 = 1400lbm per hour

90° - 50° = 40° change

1,400lbm/hr * 0.80Btu/lbm * °F * 40°F = 44,800Btu/hr

One would have to look up the specific heat of air at 34 to 44F to calculate B)

I found one source that gives a value of 0.24 BTU/lb-Fº  and a density of 0.0780 lb/ft^3 at 32°F a little lower that your air but not a lot

that gives us 0.24 * 0.078 = 0.01872Btu/ft^3 - °F, so for a 10° rise that would be 0.1872Btu/ft^3

44,800 / 0.1872 = 240,000ft^3 / hr