Parts of a Boiler
Boiler is composed of different parts which include; burner, backside water wall, boiler hood, cyclone, down corner, distribution headers , evaporator, economizer, economizer header, footing, feed water pumps ,riser, smoke uptake, steam outlet, stay tube, stays, superheated steam outlet, superheater, superheated header and steam drum.
Burners provide heat by consuming fossil fuels. They can either be separate or part of the boiler. Boiler water walls, on the other hand, are membrane barriers made of welded tubes. They hold water in its liquid state before it slowly evaporates to the boiler. Boiler hood provides adequate clean air and removes contaminated air. It is also known as a draft hood.
Cyclone is reused unburnt and heavy materials that take long to be consumed. It has several advantages that include; requires less time and cost to produce fuel, it’s smaller compared to other furnaces, its wasted is disposed of more conveniently, and it uses different types of fuels hence making it economical, reliable and flexible.
Down corner, on the other hand, are pipes that supply to the water drum from the steam drum. They also conduct steam to the steam drum from the top water wall headers. The economizer is found between the entrance of air preheater and outlet of the boiler. It uses heat from fuel fumes to heat the water being fed into the boiler. Evaporator converts water to saturated steam.
Footing in a boiler is used to ensure that the boiler is stable, and weight is evenly distributed. Risers, on the other hand, are pipes running from top to bottom of the boiler. Steam goes through these pipes to steam drum. Distributions headers are pipes direct water to riders from down corners through a heating zone where it gets heated partially. Feed water pumps, on the other hand, take water into the steam drum.
Generating tubes have been replaced by economizing tubes. They come into contact with outlet passes and also convey heat from the steam drum to the water. Although screen tubes are more or less like generating tubes, they protect superheater tubes from unnecessary heat. Water wall tubes are used where there is a need for increased insulation of boilers. This is mainly because heat will not be transmitted outside the boiler
Steam drum is made up of four plates, two dished end plates, a thick wall tube and a thinner wrapper plate. It stores steam by water tubes and prevents mixing of steam and water. Water drum is the main storage for water where all water from down corners drains. Waste materials also settle down here where they are later blown down. Currently, some modern boilers have replaced water drum with down corners
The superheater is found at the opening of the evaporator. Converts saturated steam to superheated steam. The super-heated header has pipes directed to cylinders in the superheater. Superheater tubes produce steam of superheated value, hence need protection. It is the work of screen tubes to protect them. Superheater support tubes, on the other hand, provide support to the superheater tubes so as to be able to bear its weight. Stay is fitted in a boiler to prevent destruction by internal pressures.