Boiler | Definition, Principle & Working, Properties, Classification &Component

Boiler A Boiler or steam generator basically is a compartment into which water can be bolstered and steam can be…

By admin , in THERMODYNAMICS , at March 3, 2020

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Boiler

A Boiler or steam generator basically is a compartment into which water can be bolstered and steam can be taken out at wanted pressure, temperature and stream.
For that the evaporator ought to have an office to consume a fuel and discharge heat. Along these lines the capacity of a heater can be expressed as :

i. To change over compound vitality of the fuel into heat vitality.

ii. To move this warmth vitality to water for dissipation too to steam for super warming.

Schematic diagram of Boiler

Definition of Boiler

It is characterize as a shut vessel wherein steam is created from water by ignition of fuel.

A boiler is a closed pressure vessel strongly constructed of steel or iron where water is converted into steam by the application of heat.

Efficiency

The efficiency of a boiler may be defined as the ratio of amount of steam generated per hour to the amount of heat supplied by the fuel per hour.

Efficiency ( η ) = ( Heat Output / Heat Input ) × 1oo

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Principle & Working of Boiler

Principle

In an evaporator, the warmth vitality of the pipe gases move to the water through convection. The fuel is consume into the heater which produces vent gases.
These pipe gases ignore the water containing in shell or cylinder as indicated by the sort of heater. The warmth of the vent gases move to the water and convert it into steam.

Working

A boiler is simply heat exchange in which, water is work as cold fluid and flue gases works as hot fluid. The heat flow is transfer from hot fluid to cold fluid through convection which increases the energy of water.
A container half filled with water. The fuel is consume and the vent gases stream over the holder. These gases heat the water and covert it into steam.
This steam taken out from a cylinder arranged upper side of the holder. The equivalent measure of water is feed into the holder by the feed valve which keep up the kettle pressure unaltered.
If the steam escaping rate is high compare to water feeding rate,the pressure of boiler decreases. What’s more, if the water nourishing rate is high contrast with steam getting away from rate the weight of the heater increments. Thus pressure is control with the help of fuel supply and water supply of container.

Function & Properties of a good boilers

To change over substance vitality of the fuel into heat vitality.
To move this warmth vitality to water for dissipation too to steam for super warming.
It can be started or stopped quickly.
It should have a constant and through circulation of water.
All pieces of heater ought to be open for cleaning and review.
It should be trouble free & require less attention and less maintenance.
It ought to have high pace of warmth move and better burning effectiveness.
They having free from manufacturing defects.
It should be able to accommodate the load variation.
They having maximum steam generation rate within minimum fuel consumption.
Initial cost, running cost & maintenance cost are not high.

Classification of Boiler

The boilers may be classify mainly on the basis of the following parameters:

1. Axis of the shell

a. Vertical

b. Horizontal

c. Inclined

2. Use of boilers

a. Stationary

b. Portable

3. Tube contents

a. Fire tube

b. Water tube

4. Furnace position

a. Externally fired

b. Internally fired

5. Method of water circulation

a. Natural circulation

b. Forced circulation