Typical UA values for industrial large air heater

[GeminiII]

Hi!
Can anyone suggest to me the U (or UA) values/curve of an available water-to-air fin tube heat exchanger for industrial purpose (drying of cereal large size: 200'000 ton/hr of air - 3000 kW ).

 

[speco]

GeminiII,

I'll take a stab at this one. If you use a typical 1" OD tube with 5/8" high aluminum fins at 10 fins/inch, the surface area is about 5.65 square feet per linear foot. A typical U value would be on the order of 5 to 6 BTU/(hr-sq ft-deg F). Therefore, a good estimating value would be about 31 for U * A. I'm making a lot of assumptions here, but that should be a fairly conservative value to use unless the fluid velocities are unusually low.

Regards,

Speco