Horizontal boilers are widely used in industries to provide high temperature steam or large quantity of hot water to meet the need of industries. The common boilers include coal fired horizontal boiler, oil fired horizontal boiler, gas fuel boiler, and so on. The efficiency and usage of them is different from each other. Especially for coal fired boilers, the setting of chimney is also an important factor that affects the efficiency of boiler.
Diameter of the chimney
The diameter of the chimney exit should be set according to the capacity of boiler. When the boiler is operating with the largest load, the smoke flow rate in chimney should not be too fast, in case of a big resistance of smoke flue and incomplete combustion of fuel. More seriously, a large quantity of CO, SO2, NOx will be produced to pollute environment and the CO in boiler room is dangerous for boiler operators. When the boiler is operating with the lowest load, the smoke flow rate in chimney should not lower than 2.5~3m/s to prevent the air outside from coming in through chimney.
Height of chimney
A chimney must be high enough to prevent smoke, grit, dust, gases and fume emissions from damaging health or causing a nuisance. Local council can refuse approval for a chimney that is not a sufficient height. When the total capability of the horizontal boiler is more than 40t/h, the height of chimney should higher than 45m. Besides, the chimney should be three meters higher than the buildings within a radius of 200m.
The chimney should be equipped with maintenance ladder and lightening rod and be check and clean regularly to keep in a normal condition.