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Babcock And Wilcox Boiler: Parts, Mountings, Working, Advantages and More

In this article, you’ll learn what is Babcock And Wilcox Boiler its working principle, parts, advantages, and more with PDF download.

What is Babcock And Wilcox Boiler?

Babcock And Wilcox Boiler is a stationary water tube boiler. It consists of a steam-water drum. a short tube connects the steam water drum with the uptake header and down header as shown in the figure. A mud box is equipped with each down space header and the mud collected, is removed.

Babcock and Wilcox boiler

There is a slow-moving chain on which coal is fed from the hopper. The firebricks baffle wall deflected the hot gases and helped the hot gases to leave the chimney. The dampers are used to regulate the draught and are operated by a chain and a pulley.

Read also: Different Types of Steam Boilers

Parts of Babcock and Wilcox Boiler

Following are the important parts of Babcock and Wilcox Boiler.

  1. Water drum
  2. Down take header
  3. Uptake header
  4. Water tubes
  5. Baffle plates
  6. Fire door
  7. Grate
  8. Mud box
  9. Feed check valve
  10. Furnace
  11. Dampers

1. Water Drum

It is a horizontal axis drum containing water and steam. It is connected by a short tube with an uptake header or riser at the back end.

2. Downtake Header

This is present at the rear end of the boiler and joins the water tubes to the rear end of the drum. It collects the water from the drum.

3. Uptake Header

It is present at the front end of the boiler and is attached to the front end of the drum. It transmits the steam from water tubes to the drum.

4. Water Tubes

These are the tubes in which water passes and changes into steam. The water tubes (10 cm diameter) are inclined horizontally and connect the uptake header to the downtake header. Due to its inclination, the water tubes are not filled with water, and water and steam are easily separated.

5. Baffle Plates

The Baffle plates are present within the water tubes. It causes hot gases to move upwards and downwards and again upwards before leaving the chimney. Baffle plates are provided to deflect hot flue gases.

6. Fire Door

It is applied to burn solid fuel in the furnace.

7. Grate

It is a platform, in which the solid fuel (coal) is burnt.

8. Mud Box

A mud box is provided with each down-take header and the mud, that is settled down is removed.

9. Feed Check Valve

It is employed to fill water in the drum.

10. Furnace

The furnace is placed under the uptake header. In which the fuel is burnt.

11. Dampers

The dampers are operated by a chain that passes over a pulley to the front of a boiler to regulate the draught.

Read also: Boiler Mountings and Accessories: Types, and Their Working

Boiler Mounting and Accessories

The following are the several boiler mounting and accessories used in this type of boiler:

  1. Water level indicator
  2. Pressure gauge
  3. Safety valve
  4. Superheater
  5. Stop valve

1. Water Level Indicator

It is an important fitting, which indicates the water level inside the boiler drum to an observer.

2. Pressure Gauge

A pressure gauge is used to measure the pressure of the steam inside the boiler drum.

3. Safety Valve

This is a device attached to the steam chest to prevent explosions due to excessive internal pressure of steam.

4. Superheater

A superheater is the main part of a steam-generating unit. The superheater is used to increase the temperature of saturated steam without raising its pressure.

5. Stop Valve

It is the largest valve on the boiler. It is used to control the flow of steam from the boiler to the main steam pipe and to shut off the steam completely when required.

Working of Babcock and Wilcox Boiler

Coal is fed to the grate through the fire door and is burnt. The hot exhaust gases expand upward and pass across the left side of the water tubes. The baffles deflect the flue gases and hence the flue gases travel in a zig-zag manner over the water tubes and along with the superheater. The exhaust gases leave the atmosphere through the chimney.

The portion of the water tubes, which is just above the furnace, is heated comparatively to a higher temperature than the rest of it. Water rises into the drum through the uptake header. Here the steam and water are distributed in the drum. Steam, which is lighter is being collected in the upper part of the drum. The water from the drum comes down through the down header into the water tubes.

Continuous circulation of water from the drum to the water tubes and vice versa is thus maintained. The circulation of water is maintained by convective currents and is known as “natural circulation”. Steam is taken from the steam space through tubes to the superheater. Steam is superheated in the superheater.

The boiler is fitted with the necessary mountings for safe operation. The water level indicator and pressure gauge are attached to the boiler at its left end. The stop valve and steam safety valve are mounted on the upper side of the drum. Blow-off cock is provided for the periodical removal of mud and sediments collected in the mud box.

Features of Babcock and Wilcox Boiler

  1. The overall efficiency of the Babcock and Wilcox Boiler is significantly greater than that of similar water tube boilers.
  2. Maintaining the boiler is made easier just by replacing the defective tubes.
  3. This boiler’s design results in little draught loss, which improves energy efficiency.
  4. The water tubes are slanted at 15° to allow for effective water circulation.
  5. The Babcock and Wilcox Boiler performs better than other boiler types because it can operate at higher pressures and produce more steam.

Advantages of Babcock and Wilcox Boiler

The following are the advantages of Babcock and Wilcox boiler:

  1. This boiler produces steam up to 2000 to 40000 kg/hr.
  2. It takes less space as compared to other boilers.
  3. Boiler tubes can be easily replaced.
  4. It is the only boiler that is used to produce a huge quantity of heat in power plants.
  5. In this boiler, the draught loss is low.
  6. It can be easily repaired and cleaned.
  7. High overall efficiency.

Disadvantages of Babcock and Wilcox Boiler

The following are the disadvantages of Babcock and Wilcox boiler:

  1. Large maintenance cost.
  2. It is not suitable for impure and sedimentary water. In the case of impure and sedimentary water, the scale may accumulate in the tubes and this causes the tubes to overheat and burst. The water treatment is necessary before feeding in a boiler.
  3. A continuous feedwater supply is needed to work. If continuous water is not supplied even for a short duration of time, in this case, the boiler is overheated. The water level must be strictly observed during the process of the Babcock and Wilcox boilers.

Applications of Babcock and Wilcox Boiler

The following are industrial uses of Babcock and Wilcox boilers:

  1. Steam power stations employ these types of boilers to generate electricity.
  2. This boiler is necessary for industrial operations that need steam under high pressure.
  3. It is employed in marine applications for auxiliary and propulsion power.
  4. These boilers are frequently found in the heating systems of businesses and factories.
  5. These are used to produce steam in a variety of sectors, including the processing of chemicals, textiles, and pulp and paper.


That’s it, thanks for reading. Now, I hope that you have learned about Babcock and Wilcox boilers and their different parts and working. If you have any questions about “Babcock And Wilcox Boiler” ask in the comments section.

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Read more articles on the boiler in our blog:

  1. Cochran Boiler
  2. Simple Vertical Boiler
  3. Loeffler Boiler


What is the working principle of Babcock and Wilcox Boiler?

Since the hot flue gases come in contact with the water tubes, they transfer heat with the heater and convert it to steam. Thus there is a continuous movement of water from the drum to the water tubes and from the water tubes to the drum.

Why Babcock and Wilcox Boiler is used?

The Babcock and Wilcox boiler is used in almost all power generation industries because it can produce high-pressure steam. This high-pressure steam is further used to generate electricity.

Who invented the Babcock and Wilcox boiler?

It was invented by George Herman Babcock. He was born on June 17, 1832, and was an American inventor. He and Stephen Wilcox established the Babcock & Wilcox boiler company and co-invented a safer water tube steam boiler.

What is the advantage of Babcock and Wilcox boiler?

The Babcock and Wilcox Boiler has a noticeably higher overall efficiency when compared to equivalent water tube boilers. Defective boiler tubes can be easily replaced, easing maintenance.

About Saif M

Saif M. is a Mechanical Engineer by profession. He completed his engineering studies in 2014 and is currently working in a large firm as Mechanical Engineer. He is also an author and editor at www.theengineerspost.com

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