Heat Gain (sensible kw) from dryers calculation 2

[Hussey83]

Hello experts,
I've been trying to calculate the sensible heat gain from a commercial dryer for the past two days but no positive results. Can someone here guide me on how it can be done. Thanks

 

[ChrisConley]

What is the input?

Gas or electric?

Heat gain will be a percentage of input.

 

[Hussey83]

Hello Chris, thanks for replaying its for the Milnor gas dryers.. kindly see attached link

 

[MintJulep]

The simplest method would be to call the manufacturer and ask them.

 

[MechEngNCPE]

550 MBH input, 3600cfm

Qs=cfm*1.08*(dt)
Qs=3600*1.08*(70)=272MBH bringing air from 70degF to 140degF, now if the discharge temp is higher, you will have less gain to the room, as your dT will be larger.

550MBH-272MBH=278MBH gain. See what the outlet temp is and you will have it.

 

[MintJulep]

Sensible heat equation is not good enough.

It's a drier remember. You are vaporizing maybe 40 pounds of water in the process. You need to work out the latent process as well.

Then energy balance approach will work of course, you just need to account for all of the energy.

 

[MechEngNCPE]

oh thats right, sorry, Qt=4.5*cfm*dH

 

[cdxx139]

Does a 23 ton sensible load seem high?


knowledge is power

 

[Hussey83]

Awesomw thanks guys.. this should do

 

[walkes]

Depending on the installation, the heat gain to the occupied space may be negligible. The body of the dryer will be in the back of house space where all of the combustion/make-up air is (can be) introduced. Cycle time of the dryer will impact things, but for worst case you can assume they are all running constantly.