Power plant boiler slag discharge by wind

How does boiler slagging affect power plant reliability & efficiency?

Boiler slagging and fouling, and the resulting frequent operation of sootblowers, are some of the major operations and maintenance factors that can negatively affect power plant reliability and efficiency. Boiler slagging and fouling are among the most common causes of maintenance headaches at coal-fired power plants.

What is slag in a pulverized boiler?

Slag is molten ash and incombustible byproducts that remain following coal combustion. When the material cools to a certain temperature, it can stick to furnace components, such as waterwalls, which is called slagging. A pulverized coal–fueled boiler is designed with a large furnace cavity that can tolerate liquid phase slag on the waterwalls.

Which parts of a boiler are prone to slagging?

Usually, the areas of the boiler that are designated as being susceptible to slagging are from the burner belt to the furnace exit.

What happens if lignite slag is deposited in a boiler?

Slagging and fouling can result in a serious deterioration of the heat transfer performance and the alkali metal salts in the deposited slag may cause corrosion problems [4,5], especially when an off-design coal such as the Zhundong lignite with a high content of alkali elements is chosen for combustion [6,7] by the boiler owner.

Are ash-induced slagging and fouling problems a problem for coal-fired boilers?

The ash-induced slagging and fouling problems are difficult to avoid for coal-fired boilers as coal always contains some mineral ash.

How to remove slag from Waterwall?

The most direct method for cleaning slag is the soot-blowing method. Almost all coal-fired utility boilers in China and the other parts of the world are equipped with effective soot blowers for eliminating the slagging of waterwall [ 10 ].