Boiler | Types, Applications, Characteristics

Table of Contents

What is a Boiler?

A boiler is a closed vessel which is used to heat a fluid (generally water). Fluid can either be heated or boiled. Output of boiler (steam or heated water/fluid) is further be used according to the requirement (like steam based power generation, central heating, cooking etc.).

Classification of Boilers

A). On the basis of furnace charging

Fluidized bed combustion
Pulverized fuel
Supercharged fuel

B). On the basis of Pressure of steam generated

Supercritical
Sub-critical
High-pressure
Medium-pressure
Low-pressure

C). On the basis of position of furnace

Externally fired
Internally fired

D). On the basis of position of boiler

Horizontal
Inclined
Vertical

E). On the basis of use

Marine Boiler
Stationary Boiler
Locomotive
Portable Boiler

F). On the basis of circulation of water

Forced Circulation
Natural Circulation

G). On the basis of relative passage of hot air and water

Fire tube boiler
Water tube boiler

H). On the basis of fuel firing

Gaseous fuel firing (e.g. LPG, LNG, PNG)
Liquid fuel firing (e.g. Furnace oil, Light Diesel Oil)
Solid fuel firing (e.g. Rice husk, Briquettes, Pet Coke, Wood, Coal)

I). On the basis of furnace

Dual furnace
Single furnace

J). On the basis of Drum

Multi Drum
Single Drum

Characteristics of a good boiler

All the parts should be available for cleaning and inspection
Scaling should not happen on heating surfaces
It should require low maintenance
It should acquire less floor space
It should have low vibration
It should have low initial cost
It should have high combustion efficiency
It should have high rate of heat transfer
It should have low running cost
Dismantling should be easy
It should have adequate safety interlocks
It should have low maintenance cost
Its starting and stopping should be quick
Installation should be easy
For a given fuel consumption it should have maximum rate of steam generation

Applications of boiler

Thermal Power Plant
Sugar Plants
FMCG industry
Plywood industry
Textiles
Food processing industry

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Featured image source:

By I, Sir Iwan, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2314572