A boiler that has been running for a long time is sure to have soot deposits on its tubes and furnace.This is especially prominent in boilers using heavy fuel oil for burning. Although
fuel will be heated and filtered before combustion, it still contains a lot of impurities. The by-products of combustion as well as imperfect combustion cause
soot to form. The soot is deposited on
heating surfaces.
During
combustion of
fuel oil in a steam boiler, hot gases are formed. These hot gases are used to heat up
water in
boiler to form steam.
With
deposits of soot, a lot of
heat energy is not able to be transferred to
water, but instead is lost through
chimneystack. The soot layer acts as a heat insulator for
tubes and shells of
furnace. The heat is unable to reach
water.
This not only causes
boiler efficiency to be lowered, but a more serious problem can also occur. The soot can catch fire!
A soot fire can be detrimental to
strength of
boiler because it can cause serious localized hotspots to occur at
tubes. These localized hotspots can even reach temperatures that weaken
materials of
tubes.
Soot blowers are installed to blow away these soot deposits. Steam is normally used as a medium for blowing away
soot.
The operation of
soot blowers goes like this: