The Draught in Locomotive Boilers

The draught in locomotive boilers is produced by a steam jet. This process is known as steam jet draught or steam jet blast. Let's delve into the details of how this works.

What is Draught?

Draught refers to the flow of air or gas through a boiler or furnace. It is essential for the combustion process as it supplies the necessary oxygen for combustion and removes the products of combustion such as smoke, gases, and ash.

The Importance of Draught in Locomotive Boilers

In a locomotive boiler, draught is particularly important because it plays a vital role in maintaining the steady flow of gases and efficient combustion. It ensures that the fire in the firebox is supplied with sufficient oxygen, resulting in complete combustion of fuel and efficient heat transfer.

Steam Jet Draught

Steam jet draught is a method of producing draught in locomotive boilers by using a steam jet. A steam jet is a high-velocity jet of steam that is directed into the chimney or smokebox of the locomotive.

Working Principle

The working principle of steam jet draught involves the following steps:

1. Steam is supplied to the nozzles located at the base of the chimney or smokebox.
2. The steam jet is directed into the chimney or smokebox, creating a high-velocity jet of steam.
3. As the steam jet exits the nozzles, it creates a low-pressure area inside the chimney or smokebox.
4. This low-pressure area causes a suction effect, drawing in air from the firebox and creating a flow of gases through the boiler.
5. The air drawn in provides the necessary oxygen for combustion, while the flow of gases removes the products of combustion.

Advantages of Steam Jet Draught

- Steam jet draught is a simple and reliable method of producing draught in locomotive boilers.
- It does not require the use of additional mechanical devices such as fans or blowers.
- The steam jet can be easily controlled to adjust the draught as per the requirements of the locomotive.

Conclusion

In conclusion, the draught in locomotive boilers is produced by a steam jet. This steam jet draught method utilizes the high-velocity jet of steam to create a low-pressure area, which in turn creates a suction effect and draws in air for combustion. This process ensures efficient combustion and heat transfer in locomotive boilers.