Question

Difference between fire tube an water tube boiler

Answer 1

Water Tube Boiler:

Water circulates in tubes and heated externally by hot gases.
Fuel is burned inside the furnace. i.e (hot gases- outside the tubes and water- inside the tubes).
Operating pressure = upto 100 bar
Efficiency = upto 90%
Steam generation rate is high.
Operating cost is high.
Bursting risk is high.
Water treatment is necessary.
Best example from our daily life is Pressure cooker.
Famous water tube boilers are : Babcock & Wilcox boiler, Foster wheeler D-type boiler, Foster wheeler ESD type boiler etc.

Fire Tube/Smoke Tube Boiler:

Hot gases (products of combustion) pass through tubes, running through a sealed container of water i,e (hot gases- inside the tubes and water- outside the tubes).
Also called as smoke tube boiler.
Operating pressure - limited to 16 bar.Steam generation rate is lower.
Generally, internally fired.
Operating cost is low.
Bursting risk is less.
Efficiency = upto 75%
Famous fire tube boilers are : Cochran boiler, Lancashire boiler, Scotch boiler etc.

hope this helps you....!!