What is a Lamont Boiler? | How does a Lamont Boiler Work?

This article explains the Lamont boiler working, components, and applications.

What is a Lamont Boiler?

Lamont boiler is an internally fired water tube boiler that forces the water to circulate into the water tubes by using an external pump. It is a forced circulation boiler.  

Lamont Boiler

In the Lamont boiler, the water moves inside the tubes, and flue gases are present around these tubes. When the water passes through the tubes, it receives heat from the flue gases.

The flue gases increase the pressure and temperature of the water and convert it into steam. This steam is then forwarded into a separate section and gets superheated before being forwarded to the steam turbine.

Lamont Boiler was invented by Walter Douglas La-Mont in 1925. These were the first forced circulation boilers designed solely for ships.

Lamont boiler contains an external feed pump. This pump is used to pump the water inside the water tubes. That is why the natural circulation boiler has lower water pressure than the pressure of the water tubes.

The Lamont boilers are most commonly used in hydroelectric power plants to generate electricity.

Working of Lamont Boiler

The centrifugal pump is used in the Lamont boiler for the forced circulation of the water. In this type of boiler, the water circulates inside the water tubes while the flue gases flow outside the tubes. The flue gases transfer heat to the water through the convection process.

Lamont Boiler Working

The Lamont boiler works in the following way:

  • First of all, the pump pumps water from an external source into the economizer. The economizer then heats up the water to some degree.
  • The water is then pumped to the water tubes from the economizer with the help of the centrifugal pump.
  • As the preheater air enters the furnace, it increases the air by burning coal. When the preheater air receives heat from the fuel, it transforms into flue gases.
  • These flue gases get heated and circulate around the tubes, increasing the temperature of the water in the tube and turning it into steam. This process results in the production of a mixture of saturated steam and water.
  • This mixture of saturated steam and water is then sent to the separator drum to separate the steam from the water.
  • The separator drum is the external element of the boiler. It separates the steam from the water and sends the output steam to the superheater.
  • The superheater again heats up the steam and increases its temperature.
  • When the steam gets heat from the superheater, it transforms into a superheated phase.
  • The water vapors extracted by the saturated steam are sent back to the economizer. Again, the preheated air is sent into the furnace. This again heats up the water tubes. This cycle is then repeated, converting all of the water into steam.

Components of the Lamont Boiler

The components of the Lamont boiler are given below:

1) Feed Pump

It supplies the feed water to the boiler. It enhances the pressure of the water that has to be fed into the boiler. The feed pump takes water from an external source and pumps it into the boiler tubes.

2) Grate

The grate is located at the furnace base. Grate has coal that burns in the furnace and provides heat to the combustor.

3) Blower

The blower picks up air from the atmosphere and drops it into the air preheater.

4) Distributing Header

It has two valves on each end. A suction valve is attached to one end of the distributing header, while the discharge valve is attached to the other end.

5) Circulating Pump

The boilers usually have a centrifugal pump that works as a circulating pump. A turbine is used to drive this pump.

The steam from the boiler is fed to the turbine. The circulating pump collects the water from the steam-separating drum and transfers it to the distributing header to the water tubes.

6) Radiant Evaporator

A radiant evaporator converts the water into saturated liquid and then to steam. It uses the heat of the burning coal to change the phase of the water.  

7) Superheater

The superheater heats up the steam and ensures that there will not be any single particle of water in the steam. This superheated steam is then used to turn the turbine.

8) Steam Separating Drum

When the radiant evaporator of the Lamont boiler converts the water into steam, then this steam is transferred into the steam separating drum. This output steam contains water vapors. The main function of the separator drum is to separate water vapors from the steam.

After separating the steam, the water is transferred to the water tubes by using a centrifugal pump. But the steam is transferred to the superheater for the superheating process.

9) Convective Evaporator

In this evaporator, the saturated water is converted into saturated steam.

10) Economizer

The economizer is one of the most vital parts of the Lamont boiler. It improves the efficiency of the boiler. It preheats the water by using the flue gases present in the combustor.

11) Combustion Chamber

All the solid fuels, such as coal, are burnt in the combustion chamber, and heat is produced as a result of this burning process. This heat then heats up the air and makes flue gases. These gases are then used to convert the water into steam.

Read More: Cornish Boiler Working and Applications

Construction of the Lamont Boiler

In the Lamont boiler, the air preheater is attached to the air blower. This blower takes air from the atmosphere, increases air pressure, and sends it to the preheater.

The economizer is attached to the water feed pump. The water gets preheated in the economizer. One end of the economizer is attached to the steam separator drum. After preheating the water, the economizer transfers the water to the separator drum.

The radiant evaporator is attached to one end of the steam separator drum. A radiant evaporator is placed near the combustor. The radiant evaporator is further attached to the convection evaporator.

The superheater is also attached to the steam separator drum. The superheater takes steam from the steam separator drum and transforms it into a superheated form. This superheated steam is transferred to the turbine in order to produce electricity.

Lamont Boiler Disadvantages

  • Maintenance and repair: This boiler requires more maintenance and repair than other boilers due to its complex design.
  • Water treatment: Water treatment is required in this boiler to avoid corrosion and scaling.
  • Limited temperature and pressure range: Due to the limited temperature and pressure range, it cannot be used in high-capacity power plants.
  • Corrosion and erosion: Due to the use of water as the working fluid, this boiler faces corrosion and erosion over time.
  • Efficiency: The Lamont boiler is less efficient than advanced boilers.

Applications of the Lamont Boilers

  1. Power generation: Lamont boilers are most commonly used in power plants for electrical power generation. These boilers are ideal for medium-capacity power plants.
  2. Research and development: They are utilized in research and development applications to make some new and advanced boilers and materials.
  3. Marine applications: These boilers are also employed in marine applications, like giving power to steam-driven ships and submarines.
  4. Industrial processes: It is also used in industrial manufacturing, like chemical, paper, or food processing plants.

Lamont Boiler Vs Benson Boiler

The main difference between the Lamont boiler and the Benson boiler is given below:

Benson BoilerLamont Boiler
The density between the cold and the hot water is different; hence the natural circulation of water takes place here.A pump is used to forcefully circulate the water into the pump.
It is more expensive than the Lamont boiler.It is less expensive.
It is used to generate supercritical steam.It is used to produce superheated steam.
The pressure range in the Benson boiler is about 350 bars.The pressure range in the Lamont boiler is about 300 bars.
It is highly efficient.It has a simple design.
It is higher efficient.It is highly efficient.
The maximum temperature range in this boiler is about 700°C.The maximum temperature range in this boiler is about 650°C.
They are most commonly used in high-capacity power plants.They are usually used in medium-capacity power plants.
Benson boilers have higher temperatures, higher efficiency, and a wider pressure range.They have a simple design and lower cost.

FAQ Section

What is the principle of the Lamont boiler?

The Lamont boiler works on the forced circulation principle in which a pump is used to pump the water throughout the boiler.

Where can the Lamont boiler be used?

Lamont boilers are most commonly used in power plants where steam turbines are employed to generate electricity. They are also used in sugar mills.

What is the capacity of the LaMont boiler?

The steam generation capacity of the Lamont boiler is about 50 tons per hour.

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