I am having a doubt in heat transfer (mechanical engineering).

Question

I am working in an fmcg company where 'Thermic fluid lines' are used for drying chilly coriander garlic and cumin. The output of the thermic fluid is 6 lakh Kcal/hour. The load of thermic fluid line is 17 hp. How can I calculate the heat required for drying chilly line alone?

Answer 1

Hi Sarun!

 

I think I am hitting a roadblock in trying to understand your setup, and, before I can help, I would need to clear that roadblock.  The way I see your setup is, the thermic fluid line draws 17 hp; and that power is used to add heat to the thermic fluid on its way to the chile, coriander, garlic, and cumin.

 

The power output of the thermic fluid is 600,000 kcal/hour (if I am correct that lakh = 100,000 in standard US notation).  I am not sure whether this output is what is used to dry the spices, or if it power drawn off AFTER the fluid has dried the spices (similar to how a compressor in an air conditioner removes thermal energy from the cooling fluid before recirculating it).  But since I assume drying requires heat to be delivered to the spices, I am thinking my first guess may be correct.

 

But, in either case, I run into a problem.  17 hp = 12,676.9 W, which I assume is the power being put INTO the thermic fluid.  The trouble is, 600,000 kcal/hour, the power coming OUT of the fluid (by my interpretation), approximately equals 696,000 W.  By my interpretation, even if you are perfectly converting all the 17 hp into thermal energy put into the thermic fluid (which is not likely), the power output is nearly 55 times the power input.  By the conservation of energy, power output cannot exceed power input, so I must be misunderstanding something.

 

Could you help me by describing a bit more the what the output of the thermic fluid is, or does, and what the load on the line does?  Then I can help you more.