Understanding what a boiler is, types of boiler, why it is used, and what goes on inside one is crucial to understanding how a boiler functions. So The answers to these queries are crucial to grasping the boiler concept as a whole.

What is Boiler?

A closed vessel used to heat liquid, typically water, or to produce steam, vapour, or any such combination under pressure for use outside the boiler is referred to as a boiler.

Parts of Boiler

Boiler components can be divided into two groups:

Boiler mounting

These are the crucial components that determined how well the boiler performed.

Water level indicator

This is a device that is installed in the front of the boiler and used to check the water level inside of it. So It consists of three cocks and a glass tube.

Pressure gauge

This device, which is mounted on the front of the boiler, is used to gauge internal pressure.

Safety valve

This is attached to the drum and is used to stop the boiler from exploding as a result of high pressure, which blows off when the pressure inside exceeds the limit. These two are consistently present.

Stop valve

This regulates how much steam is released from the boiler into the steam pipe.

Blow off cock

This is attached to the bottom of the drum and is used to empty the boiler as well as blow off mud and water.

Feed check valve

This is installed on the drum just below the usual water level as a Non-Return Valve. So It is employed to control the flow of water.

Grate

It is the space in the furnace used to burn the fuel.

Boiler accessories

These are the parts that are responsible for the efficiency of the boiler.

Feed pump

It is utilized to continuously pump water into the boiler. So The feed pump is powered by a steam turbine or an electric motor.

Super heater

This is used to superheat the steam before it is passed in the turbine as saturated steam causes corrosion.

Economizer

The boiler’s flue gases are forced through the economizer before being released into the atmosphere, which helps the boiler run more efficiently.

Air preheater

It is also used to increase the efficiency of the boiler by preheating the air.

Working Principle of Boiler

It’s very easy to understand how a boiler operates. The boiler is a sealed container where the water is kept. When fuel is burned in the furnace, hot gases are produced. So The water vessel where the heat transfer between the water and the steam occurs is made to come into contact with these hot gases. Therefore, the boiler’s fundamental function is to use heat energy to change water into steam. So Boilers come in a variety of designs and serve a variety of functions.

Efficiency of Boiler

The proportion of overall heat exported by the outlet steam to the total amount of fuel supplied is known as the boiler’s efficiency.

Boiler efficiency (%)=(heat exported by outlet steam/heat supplied by the fuel)*100

Classification of Boiler (types of boiler)

The following criteria are used to categorize boilers (types of boiler).

• According to the relative passage of water and hot gases:
  • Fire-tube boiler: So A boiler with water surrounding the hot combustion gases inside of it
  • Water-tube boiler: A boiler with hot combustion gases surrounding the tubes where the water is flowing.
• According to water circulation arrangement:
  • Forced circulation: The water inside the boiler is pumped to create the circulation.
  • Natural circulation: So The disparity in densities causes the circulation.
• According to the use:
  • Portable boiler: These are movable and used temporarily in sites.
  • Stationary boiler: So These boilers are used for power plants
  • Marine boiler: These are used in ships.
  • Locomotive: So These are used in the railway engines.
• According to the position of boilers:
  • Inclined
  • Horizontal
• According to the pressure generated by steam:
  • Medium pressure boiler: So The maximum pressure is 20-80 bars. It is used for power generation.
  • Low-pressure boiler: So The maximum pressure is 15-20 bar. It is used for heating purposes.
  • Sub-critical boiler: If the boiler produces steam at a pressure that is less than the critical pressure it is known as sub-critical.
  • High-pressure boiler: The maximum pressure is more than 80 bars.
  • Supercritical boiler: These boilers are used to produce steam at a pressure which is greater than the critical pressure.
• According to charge in the furnace:
  • Supercharged fuel
  • Pulverized fuel

Applications of Boilers

The following industries have a variety of uses for the boiler:

• Chemical industries
• Food processing industries
• Thermal power plants
• Refineries and distilleries
• Textile industries
• Sugar plants
• Paper industries
• Health care industries
• FMCG (Fast Moving Consumer Goods)
• Pharmaceutical industries