Heated cure tunnel, non combustion 2

[chevelle68]

Hi, need to build a heated tunnel to cure a painted product, but cant be direct fire heated? I was thinking of a boiler and running piping thru a heat exchanged to warm up the tunnel. Any other ideas out there, that would work better and be cost effective and not an explosion threat lol

 

[Fasi007]

Why dont you try Electric heaters?

 

[dvd]

indirect-fired burner with tubular heat exchanger and circulation fans to move air inside the tunnel.

http://www.maxoncorp.com/Directory/product_detail/INDITHERM/28/

 

[chevelle68]

Sorry...I should have been more descriptive. New on this site lol..The product is empty and partially full propane tanks, which is why I am trying to avoid "extremely hot" surfaces and discharges just in case something happens. Need something that isn't too hot to case an explosion but will heat the tunnel efficiently.

 

[btrueblood]

"partially full propane tanks"

Not a good idea, but that is just my opinion. Empty the dang tanks first!

 

[chevelle68]

I know, but it's not up to me to empty them and there will still be residual propane inside that is an issue. Tough one!!!

 

[mcgyvr]

Not sure where you are located but in the US there are OSHA regulations about blowing radiant heat,etc... towards propane tanks. Any decent heat could increase the pressure in the tank enough to pop the safety valve and vent propane into your curing chamber and BOOM.
I'm assuming your just repainting these tanks, if so I would look into an air cured/drying product.
What is the required curing temp?

 

[vpl]

it's not up to me to empty them

The pertinent question is "Who will be blamed when they explode?"

If it were me, I'd make it a condition that they be drained and vented prior to the painting and curing.

Patricia Lougheed

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.

 

[chevelle68]

Everyone's right so far. The reason for the heated tunnel is that the hybrid water based formula, when applied at 135*F, takes 20 min. to cure at ambient air temp. We are concerned with dry time in the winter time, not so much with the fall/spring. Maybe it makes sense to just force air circ. in a tunnel opposed to introducing a form of "heat".

 

[HEC]

Just thinking out of the square, solve two problems at once. Fill the tanks with hot water. Thsi will displace any propane from the tank and warm the cylinders to enhance drying!

Mark Hutton

 

[btrueblood]

...and now you've created a corrosion concern for a pressure vessel. And added several more process steps (fill tank, drain tank, dry tank).