Development and Study of an Electrostatic Precipitator for Small Scale Wood Combustion

Wood is often combusted in small scale units for domestic heating. Although the total particle emission levels in Germany have declined steadily over the years, small scale wood combustion is an increasing source of indoor and outdoor air pollution. A novel space charge electrostatic precipitator (ESP) was developed for control of fine particle emissions control from wood combustion stoves and boilers. The ESP ionizer consists of a high voltage isolator, a screen electrode and star-form corona discharge electrode. The charged particles are precipitated in the collector which includes a grounded brush. In the article the results concerning the influence of combustion conditions in the wood-log stoves, gas temperature and flow rate, particle number and mass concentration and values of applied voltage and corona current on the ESP collection efficiency are discussed. For steady flame combustion, the mean mass collection efficiency of the ESP is ηM=87±3% for 13% O2. The fractional collection efficiency of the electrostatic precipitator is ηN>90%.