Development of an electrostatic precipitator for small scale biomass furnaces

Electrostatic precipitators are reliable and able to reduce the concentrations of dust in flue gas significantly. In biomass-fired power plants electrostatic precipitators are state of the art, but for small scale furnaces ESP-systems are a quite new technology. The challenge is to develop reliable ESP-systems for small and medium scale furnaces. Fraunhofer engineers tested and optimized an ESP-system especially with regard to the fractions PM 1.0 and PM 2.5. The goal was to develop a low cost ESP-system, which ensures compliance with emission limits. Attention was paid to ensure a good accessibility to make cleaning and maintenance as easy as possible. The ESP-system was designed to be easily combined with different types of furnaces and it is very independent from the conditions at the installation location. This flexibility is needed to respond to the requirements that result from the design and performance of the different furnaces. To optimize flexibility and separation efficiency CFD simulations were carried out. Moreover a dimensioning tool based on the Deutsch-Equation for ESP systems and the optimization of the fractional separation efficiency was developed and tested.