Lancashire Boiler: A Stationary Fire Tube Boiler

Introduction:
Lancashire boiler is a type of stationary fire tube boiler. It was invented in the year 1844 by the British engineer William Fairbairn. This type of boiler is named after the county of Lancashire, England, where it was first introduced.

Construction:
The Lancashire boiler consists of a horizontal cylindrical shell with two large flue tubes that pass through the furnace. The furnace is located at the front end of the boiler and is surrounded by water. The combustion gases pass through the flue tubes and exit into the atmosphere through the chimney. The boiler has two fire tubes that run horizontally through the length of the boiler. These fire tubes are surrounded by water and connect the front end and back end of the boiler.

Working:
The fuel is burnt in the furnace and the hot gases produced rise upward and pass through the flue tubes. The heat from these gases is transferred to the water surrounding the fire tubes. The water gets heated up and starts rising upward due to convection. The hot water from the top of the boiler is taken out through a steam dome and then distributed to the different parts of the plant.

Advantages:
1. It is a simple and reliable design.
2. It has a large heating surface area which results in high steam production rate.
3. It is capable of handling large volumes of water and steam.
4. It requires less maintenance compared to other types of boilers.

Disadvantages:
1. It has a slow response to load changes.
2. It requires a large amount of floor space.
3. It is not suitable for high-pressure steam applications.

Conclusion:
The Lancashire boiler is a stationary fire tube boiler that has been used in various industries for more than a century. Despite its disadvantages, it is still popular in some industries due to its simplicity and reliability.