The boilers are used all over the world to generate steam. There are multiple types of boilers, and Babcock and Wilcox boiler is one of them. These boilers are most commonly used to generate high-pressure steam. This high-pressure steam is employed in hydroelectric powerplants to generate electricity. This article explains the types, working, and applications of the Babcock and Wilcox boiler.
What is Babcock and Wilcox Boiler?
Babcock and Wilcox boiler is an externally fired, solid fuel fired, high pressure, horizontal drum axis, stationary, multi-tubular, natural circulation, natural draft boiler. It is a type of water tube boiler. This boiler is used in high-pressure steam requirement applications.
In 1967, George Herman Babcock and Stephen Wilcox invented this boiler. Therefore, it is known as Babcock and Wilcox boiler because of the name of its discoverer.
This is an externally fired water tube boiler. It is most commonly used to produce a large amount of high-pressure steam. In this boiler, the electric current controls the water circulation.
Working of Babcock and Wilcox Boiler
- First of all, the water is supplied to the water drum, and solid fuel is placed on the grate.
- A fire door is installed to supply fire to start the fuel burning.
- This boiler has an Uptake Header and Down Take Header. The Uptake Header and Down Take Header contain multiple holes through which inclined water tubes are passed.
- A feed pump pumps the water from the drum into the water tubes through the down-take header.
- As the fuel starts burning on the grate, it generates hot flue gases.
- As the hot flue gases come in contact with the water tubes, they transfer their heat to the water of the water tubes.
- When the water gets heat, it transforms into steam.
- The convective current is used to maintain the water circulation, and this process is called Natural Circulation.
- As the steam is generated, it moves up through the uptake header and collects in the boiler drum’s upper side.
- The boiler drum has an anti-priming pipe. This pipe separates the humidity from the steam. After this steam separation process, the dry steam is sent to the superheater.
- As the dry steam moves from the anti-priming pipe to the superheater, the superheater increases the seam temperature up to the required level and converts it into superheated steam.
- As the steam converts into superheated form, it is delivered to the steam stop valve.
- The steam stop valve transfers the superheated steam in a steam drum or to the steam turbine to generate electricity.
Parts of Babcock and Wilcox Boiler
The Babcock and Wilcox Boiler has the following major parts:
- Water Level Indicator
- Steam Space
- Water space
- Water Drum
- Superheater
- Down take Header
- Dampers
- Furnace
- Uptake Header
- Feed Check Valve
- Water Tubes
- Mud Box
- Baffle Plates
- Fire Door
- Grate
1) Water Drum
This is a horizontal drum. It contains steam and water. A short tube is utilized to connect this drum with a rise at the back end or an uptake header.
2) Down take Header
It is located at the boiler’s rear end. It connects the water line to the drum’s back end. The down-take header transfers water from the water tubes to the drum.
3) Uptake Header
It is located at the boiler front. It is connected to the drum front. The function of the up-take header is to transfer the steam from the water tube to the drum.
4) Water Tubes
The water tubes contain water. As the water passes through the water tubes, it converts into steam. The water tube (10 cm diameter) is inclined horizontally and connects the down take header and uptake header. You can easily separate the steam and water in these tubes due to the inclined position of the tubes.
5) Mud Box
Each down-take header has a mud box. As the mud settles down in the box, it is removed to the desired area.
6) Fire Door
It is a place from where the fire is supplied to fuel. This fire combusts the fuel and generates hot flue gases.
7) Grate
It is a place where the coal is placed and combusted.
8) Baffle Plates
These plates are installed in the water tubes. They help to move the hot gases up and down and up and down before exiting the chimney. They are specially designed to redirect hot flue gases.
9) Feed Check Valve
The check valve is installed to supply water into the drum. It stops the backflow of the water.
Read More: Working of Check Valve
10) Water Pump
A water pump is the most important part of the Babcock and Wilcox boiler. It takes water from the reservoir or storage drum and transfers it into the water tubes.
Read More: Different types of Pumps
11) Water Space
The water space is the area of the shell that is enclosed by water.
12) Water Level Indicator
This acts as a gauge. It indicates the water level inside the shell.
13) Steam Space
The shell volume, except for the volume of water and tube space, is called Steam space.
14) Furnace
The furnace is part of the boiler, which completely burns the fuel and generates heat. This generated heat transfers to the water tube water.
15) Superheater
This part is employed to increase the saturated steam temperature. It converts the saturated steam into superheated steam.
16) Dampers
A chain operates the dampers. This chain goes over a pulley to the boiler front end to handle the draught.
Advantages and Disadvantages Babcock and Wilcox Boiler
Advantages of Babcock and Wilcox Boiler
- These types of boilers have the capacity to generate steam up to 2000 to 40000 kg/hr.
- Babcock and Wilcox boiler requires a lower installation area than other types of water tube boilers.
- It has high overall efficiency.
- They are small in size.
- It has easy cleaning and repairing.
- They have easy installation.
- This is the only boiler used to generate a large amount of heat in a hydroelectric power plant.
- This boiler has easy maintenance.
- It has low drought losses.
Disadvantages of Babcock and Wilcox Boiler
- The maintenance cost is very high.
- These boilers are not ideal for sediment or impure water. If the water is contaminated and sedimented, the scale can build up in the water pipe, and the pipe can overheat and burst. Therefore, the water needs additional treatment before its entry into the boiler.
- These boilers need a continuous water supply for proper operation. In this case, the boiler will overheat if you do not supply water continuously, even for a short time. During the process of the Babcock and Wilcox boiler, the water level should be monitored very closely.
Applications of Babcock and Wilcox Boiler
- Babcock and Wilcox’s boilers are most commonly used in the hydropower plant to generate high-pressure steam.
- These boilers are used in hydroelectric power plants to generate a large amount of electricity.
Specifications of Babcock and Wilcox Boiler
- Working pressure = 140 bar (max)
- Efficiency = 60% to 80%
- Diameter of the drum = 1.22 to 1.83 m
- Water tube size is from 7.62 to 10.16 cm
- Length = 6.096 to 9.144 m
- Steaming Capacity = 40000kg/h (max)
- Size of the Super-heater tubes = 3.84 to 5.71 cm
FAQ Section
Who invented the Babcock and Wilcox Boiler?
In 1967, George Herman Babcock and Stephen Wilcox invented this boiler
What is Babcock and Wilcox Boiler used for?
The Babcock and Wilcox boiler is most commonly used to produce a huge amount of heat. These boilers are most commonly used in hydroelectric power plants to generate high-pressure steam for electricity production.
What is the efficiency Babcock and Wilcox boiler?
The overall efficiency of the Babcock and Wilcox boiler is higher than other boilers. This boiler has an approximately 20 tons/hour steam generation rate at a pressure of 10 to 20 bars. It has 60% to 80% efficiency.
What are the components of the Babcock and Wilcox boiler?
- Water Drum
- Down take Header
- Uptake Header
- Water Tubes
- Baffle Plates
- Fire Door
- Grate
- Mud Box
- Feed Check Valve
- Furnace
- Dampers
- Superheater
- Water space
- Steam Space
- Water Level Indicator