Boiler Accessories

BOILER ACCESSORIES

•         Economiser

•           Air Preheater

•           Super Heater

•           Steam Separator

•           Steam Trap Feed Pump

Economiser:

•         The feed water is pumped to the bottom header and this water is carried to the top header number of vertical tubes.

•           Hot flue gases are allowed to pass over the external surface of the tubes.

•           The feed water which flows upward in the tubes is heated by the flue gases.

•           This preheated water is supplied to the water.

•           Scrappers are moved slowly moved up and down to clean the surface of the tubes.

Air Preheater:

•         Hot flue gases pass through the tubes of air preheater after leaving the boiler or economiser.

•           Air and flue gases flow in opposite directions.

•         Baffles are provided in the air preheater and the air passes number of times over the tubes.

•         Heat is absorbed by the air from the flue gases.

•           This preheated is supplied to the furnace to aid combustion.

Super heater

•         Steam stop valve is opened.

•           The steam from the evaporator drum is passed through the super heater tubes.

•         First the steam passed through the radiant super heater and then to the convective super heater.

•         The steam is heated when it passes through these super heaters and converted into the super heated steam.

•           This superheated steam is supplied to the turbine through the valve.

•         The steam is allowed into the separator.

•         The steam strikes the baffle plates and the direction of flow is changed.

•         As a result, heavier particles in steam falls down to the bottom of the separator.

•         The separated steam is free from water particles.

•         It is passed to the turbine or engine through the outlet pipe.

•         The condensed water enters the steam trap by gravity.

•           When the water level in the trap rises high enough, the ball float is lifted.

•           This causes the valve to open and the water is discharged through the outlet.

•           After the discharge of water, the float moves down.

This causes the valve to close again.

DIFFERENCES BETWEEN BOILER MOUNTINGS AND ACCESSORIES:

Boiler Mountings

Mountings are fitted for the safety of the boiler.

They form integral parts of the boiler

They are usually mounted on the boiler shell

A boiler should not be operated without mountings

Boiler Accessories

Accessories are fitted to increase the efficiency

They are not integral part of the boiler

They are usually installed outside the boiler shell

A boiler can be operated without accessories