Part Cooling

[simoncad]

I am working on a project were I have to get rid of 56000 BTUs in one hour. This is a process on a conveyor. There are 800# of parts passing through in one hour. I'm not sure what temperature drop the BTUs were figured out at, but I have to drop the temperature using air knives. Does anyone know how many CFM I would need to blow on these parts at probablly 80-100 PSI, and for how long?

Thanks,

Simon

 

[MintJulep]

IRStuff:

You've got a unit problem in your earlier post.

Heat capacity in C and delta-T in F.

C/F = 1.8 ~=2

 

[MintJulep]

And no conversion from oz to gm.

Or are they invisible conversions?

 

[MintJulep]

Ok, here is how to figure this problem out.

1. Figure out how much heat you really need to remove from the parts. IRStuff's calculation earlier has the basic method, lack of unit conversions notwithstanding.

1b. Figure out how much heat you will have to remove from the conveyor, unless you have that special air that can selectively remove heat only from the product.

2. Figure out how quickly heat can transfer from the parts to the air. This will be a function of velocity. Renyolds, Nessault, Prandlt and probably a few other numbers are involved. Easier to do some tests I would think.

3. Figure out what temperature air you have available, and what temperature air you want to exhaust.

4. There you go.

Please post your completed calculation here. We're all curious.

 

[IRstuff]

The wonders and magic of Mathcad.

Lets me blithely mix units ad nauseum. ;-)

TTFN

FAQ731-376

 

[IRstuff]

If I didn't have Mathcad or something similar, I wouldn't even bother cranking some of these types of problems

TTFN

FAQ731-376