|Fig. 1: Soot Blower of Steam Boiler|
Many installtions of steam boiler are now designed to use more boilers and they depend on the type of steam boiler size, firing, fuel type, ash in fuel, slag potential, previous experience, etc. Soot blowers remove soot and ash deposits from the fire sides of heating surfaces so that they remain optimally clean and heat transfer is maintained at the original design levels. Slagged area can be cleaned periodically and one at a time.
Steam boiler tubes and heating surfaces get dirty because of accumulation of slag. With excessive slag, the waterwall absorb less heat because slag is a good insulator and reduce the effectiveness of heating surface, so decrease load and increase steam temperature beyond control limit. Every effort must be made to avoid slagging passes in the boiler. The increase in steam boiler maintenance resulting from slgging at high furnace exit temperature is well known.
For water tube boiler, soot blowers are commonly used and permanently installed but not very effective for firetube boiler. Soot blower has element that are located in the direct path of the products of combustion. Steam is blown from the nozzle in the elements at high velocity between the rows of tubes.