Cleaning of biomass boilers
Alkali in the ash of annual crop biomass fuels creates serious fouling and slagging in conventional boilers. Even with the use of sorbents and other additives, power plants can only fire limited amounts of these fuels in combination with wood.Sintered or fused deposits were found on grates and in agglomerates in fluidized beds. Potassium sulfates and chlorides were found condensed on upper furnace walls where it mixed with flyash. Convection tubes were coated with alkali chlorides, carbonates and sulfates mixed with silica, alumina and complex silicates from flyash or fluidized bed media. The limited furnace volume and high furnace exit gas temperatures of most biomass boilers promote slagging or deposits from those biofuels that contain significant amounts of potassium or sodium, sulfur, chlorine and silica.
Biomass incinerators constitute - due to their unbalanced fuel calorific values and varying pollution - problematic plants in which the desired and scheduled boiler operating periods often are not nearly reached. According to our experience it is reasonable to clean such boilers by using water, air or possibly even steam as blowing agents.
The technology of SmartCannon – characterised by individually adjustable and flexible blowing figures – is particularly suited for cleaning combustion chambers. It enables effective cleaning with a small number of blowers and low operating costs.
For the heat recovery sections in most cases air-driven sootblowers are selected.
If Smart Sootblower or Conventional Sootblowers are installed, it is unavoidable to use air or superheated steam as blowing agent. (Wet and moist steam causes caking of the fouling so that manual cleaning cannot be avoided).
- Extension of operating periods
- Reduction of maintenance costs and erosion
- Optimally clean heating surfaces