Burner Tube Cooling

[PreEng2014]

Hello,

I've been trying to solve this problem but I've been running in circles it seems.

There is a fire tube burning methane at 1500°C to heat up heavy oil inside of a 1000bbl tank.

If a trucker is pulling the oil out of the tank at the specified rate, say 1.5 m^3/min, we need to know how long it would take for the fire tube to cool down to 580°C (Autoignition temp of the gasses inside the tanks.

We need to know when the fire tube would need to shut off, so it has enough time to cool before it gets exposed to the volatile gasses. We don't know the temperature of the surface of the outside of the firetube where it is in contact with the oil, or even how to determine the heat transfer coefficients of the gasses inside of the tube, or what to use for oil.

We are assuming the gasses are not flowing inside the tube, while the oil is flowing due to forced convection on the outside of the tube.

The tube is 10" sch 40 carbon steel.

Please help!

 

[chicopee]

If you put oil instead of water in the shell of a firetube boiler and your flame temperature is 1500 dC, you are bound to sag the furnace and most of the tubes and probably melt them and have a big catastrophe. Do the sensible thing and heat up the water and heat up your oil thru a heat exchanger connected to the boiler. By the way I doubt that you will get 1500dC and most likely 1500 dF.

 

[willard3]

Hire an Engineer who does this because you are proposing dangerous stuff.