copper made heating Tank

unconventional

I am a new heat engineering student. My questions are:

1) In a fire-tube boiler, why copper is not used for furnace body and smoke pipes inside the boiler? Copper is x15 time more thermal conductive.

2) Doesn't Iron pipe/ heating tank/ furnace need more fuel to heat up (for low thermal conductivity) and keep at high temperature?

Jamie Hall

Copper used to be, years ago -- but it isn't strong enough for power boilers, it work hardens and fatigue cracks, and it is at least as prone to corrosion as black iron or some (not all) steels.

And on the second one, yes, on initial firing the mass of metal is somewhat significant, and does take a little more fuel to heat. However, the differences in thermal conductivity are not large enough -- though they are certainly significant -- to overcome the strength problems (which would require much thicker copper).

hot_rod

Copper fin tube boilers are still very common. Water in the tube, finned outer takes the heat from the burner. Raypak, Laars, RBI, and Lochinvar are the main brands.
Copper is an excellent metal for heat exchange.

EBEBRATT-Ed

Copper expands too much to use in normal designed boilers. Used in the boilers @hot_rod mentioned above is fine. They are basically a hot water coil

pecmsg

unconventional said:

I am a new heat engineering student. My questions are:

1) In a fire-tube boiler, why copper is not used for furnace body and smoke pipes inside the boiler? Copper is x15 time more thermal conductive.

2) Doesn't Iron pipe/ heating tank/ furnace need more fuel to heat up (for low thermal conductivity) and keep at high temperature?

MONEY!

ChrisJ

How about Monel?