Electrostatic precipitation in a small scale wood combustion furnace

Wood combustion generates a high concentration of particulate matter emission, but most of the particulates in the exhaust gas can be filtered through an electrostatic precipitator. The objective of this paper is to model the trajectory of particulates in the exhaust chimney of a small scale wood combustion furnace with an electrostatic precipitator. The precipitator consists of a central electrode subjected to a maximum high voltage of 50 kV and an outer electrode of 180 mm diameter, ground potential. The parameters including particle size, ambient temperature, pressure, gas flow rate and the applied voltage have been varied while computing the trajectories of the particles in the chimney. The trajectories of particulates have been analyzed for different sizes of a typical wood combusting stove by taking different forces into account on particulates. The critical conditions give the trajectory of particles as a function of particulate size and applied voltage together with the function of efficiency. (C) 2011 Elsevier B.V. All rights reserved

CFD modelling of flue gas particulates in a biomass fired stove with electrostatic precipitation

The biomass fired stoves have been used in medium and large scales applications from several years and are utilizing electrostatic precipitator technology. Biomass based technologies are considered as renewable energy source and less harmful to the environment. The combustion of biomass generates a high concentration of flue gas particulates. The most of the flue gas particulates in the exhaust gas can be filtered through an electrostatic precipitator. In this work, a computational fluid dynamic (CFD) model has been developed for analysing the trajectory of particulates in a small scale domestic stove using biomass material. It is considered that electrostatic precipitator is based on an approach where both charging and precipitation of particulates takes place within the same set of electrodes. The precipitator is mounted in a vertical chimney of diameter 180 mm containing a central high voltage corona source. The model is based on biomass combustion models utilising a Eulerian-Lagrangian reference. The developed CFD model demonstrates the efficiency of the removal of charged particulates of the flue gases and also the interaction of the electric field in a semi turbulent flow together with the combination of the ion wind. Also it includes the effects of space charge within the system. In the modelling, modifications have been made to the grounded cylindrical collector of electrostatic precipitation through a re-design to include a series of inclined baffle plates for improving the particulates' collection efficiency