Design and characterisation of an electrostatic precipitator for small heating appliances

Promoting the use of renewable sources of energy is part of the efforts being undertaken to tackle the problem of global warming due to the greenhouse effect. Generation of heat or energy by wood combustion takes advantage of a renewable and often locally available source of energy and can help to reduce the overall emissions of CO2. Particularly small wood-fired appliances, however, are significant sources of air pollution. In addition to CO, VOC or NOx, high emissions of particulate matter are a major drawback of these appliances. The work presented here results from efforts to improve small heating appliances burning solid fuel. For application in small heating systems, a compact and inexpensive solution that still offers a significant reduction of particle emissions is required. In this paper, a specific design of electrostatic precipitator (ESP) is presented and its collection efficiency and electrical characteristics are evaluated. Different geometries and electrode set-ups have been considered with the aim of developing a system that can also be retrofitted to existing installations.