horizontal multitubular water tube boiler

water wall enclosed furnace type

vertical tubular fire tube type

horizontal multi-tubular fire tube type

stationary fire tube type

horizontal type

natural circulation type

all of the above.

flue gases pass through tubes and water around it

water passes through the tubes and flue gases around it

forced circulation takes place

tubes are laid vertically

ash

volatile matter

moisture

hydrogen

zero

one

two

four