What is the primary purpose of a water back on a stoker?

The primary purpose of a water back on a stoker is to cool the back wall and prevent clinkers. In a stoker-fired boiler, the combustion process generates significant heat, and this can lead to the formation of clinkers, which are hard, fused ash deposits. If the back wall of the furnace overheats, it can exacerbate clinker formation, obstructing the flow of gases and reducing overall efficiency.

By utilizing a water back, the back wall is maintained at a lower temperature through the circulation of water. This cooling effect helps in controlling the temperature within the furnace, ensuring that the ash remains manageable and does not solidify into clinkers. Keeping the back wall cool also protects it from thermal stress and potential damage, thus enhancing the longevity of the equipment and the efficiency of the combustion process.