Boiler Accessories

BOILER ACCESSORIES

Boiler Accessories are the devises fitted in a boiler in order to increase the efficiency of the boiler and for proper working of the boiler. Boiler accessories are:

1. Economizer

2. Air Preheater

3. Superheater

4. Steam Separator

1. ECONOMIZER

Economizer is a feed water heater. It derives heat from the flue gases discharged from the boiler.

2. AIR PREHEATER

The heat carried with the flue gases coming out of the economizer is further utilized for preheating the air before supplying to the combustion chamber. Air preheater preheats the air supplied to the combustion chamber by using the heat of the flue gases coming out of the economiser.

1. It is found that an increase of 20° C in the air temperature increases the boiler efficiency by 1%.

3. SUPERHEATER

The function of the superheater in the thermal power plant is (i) to remove the last traces of moisture (1 – 2%) from the saturated steam coming out of the boiler and (ii) to increase its temperature sufficiently above the saturation temperature.

The superheating raises the overall efficiency. It also avoids too much condensation in the last stages of the turbine, which avoids the blade erosion.

The heat of the combustion gases from the boiler furnace is utilized for the removal of moisture from steam and to superheat the steam. Superheaters usually have several tube circuits in parallel with one or more return bends, connected between the headers.

4. COMPARISON OF BOILER MOUNTINGS AND BOILER ACCESSORIES