optimal fin height 6

[huckle]

We have cylindrical tank. It is made of ½" thick carbon steel. It's dimensions are 7' x 20'. We need to install fins (flights) inside tank to facilitate heat transfer. We need to know the optimal fin dimensions for effective heat transfer. The flights would be made of carbon steel. Due to the material inside the cylinder, the flights must be at least ½" thick.

Tank data:

Indirectly heated exterior with air up to 1400 F, velocity 45 feet per second.

What would be an optimal fin height inside the tank to maximize heat transfer?

 

[ione]

Forced convection will take place on the outside of the tank, while you intend to enhance the heat exchange surface putting fins inside the tank. Could you give us some other info about the scenario you’ve inside the tank?

On second instance, have you considered rapid oxidation as possible issue for carbon steel in contact with air at that temperature?

 

[CastMetal]

The more steel surface area inside of the tank the greater the heat transfer. You will have diminishing returns as the fins get taller the tips of the fins will be cooler. At a certain point the tips of the fins will be close to the temperature of the fluid in the tank. At that point increasing the fin height gives little benefit.

 

[Twoballcane]

I think you have to start with what do you want your fluid delta temp btw the in and out to be at what gallons per minute (gpm).
Then you can calc how much heat you have to move from the fluid to your heat sink. With this info, you can calculate the fin height as needed. The right fin height will be the one that works for your application.


Tobalcane
"If you avoid failure, you also avoid success."
“Luck is where preparation meets opportunity”

 

[hacksaw]

fins inside? they would be useless

 

[racookpe1978]

"External air" at 1400 degrees? That would almost imply an external open-air burner exhausted/directed right at the tank wall.

Doesn't make sense -> As mentioend, Wouldn't you need the fins to be on the "gas" side of the tank, not the liquid side?

 

[IRstuff]

You'd be better off with some sort of stirrer. Most liquids are too viscous to have decent convection without some active agent.

TTFN

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