Fire chamber vent tubes

[Hawke]

I see vent tubes from fire chamber on some engines. Im guessing to release buildup off heat. But why is this needed. Why not use less heat?

[Ian S C]

You need the vents, you have to draw in fresh air/oxygen to get the burner to burn, so a bit of air/heat out draws more in the bottom. Ian S C

[Hawke]

Ahh, ok. Ive just used tea lamps so far really. The higher flame alcohol or propane would need the draft. Thx

[theropod2]

Ahh, ok. Ive just used tea lamps so far really. The higher flame alcohol or propane would need the draft. Thx

If the engine has a hot "box" end the vent opening can be a little lower so the most intensely heated air stays in the upper part of the heat chamber/fire box. With this redirection of the excess heat up and away, via a chimney, the cool end isn't warmed by convection as this otherwise is the case as the heat just naturally pelts the cool end on a vertical engine. A damper can be installed to adjust the flow rate to match the heat input. I think these heat bleeders are a good idea.

Stirling fans would sure benefit, as the waste heat/fumes cold be directed away from the area to cool, and might get the rpm up a little.

One could drive a little LTD off the top of the waste heat tube. That would be cool.

R

[fullofhotair]

theropod2,
I really like that idea of using the vent pipe tube to run a small fan. That could cool a thermosyphon radiator to the cool side.