Electrostatic prccipitators (ESP) arc the most commonly used devices for gas cleaning in the power industry. From the beginning of ESP usage on a commercial scale, it has been said that all swirls and turbulences should be eliminated from the gas flow, approaching uniform gas distribution in an ESP chamber. Application of CFO (Computer Fluid Dynamics) methods in electrostatic precipitation caused radical changes in views on the role of the gas flow. Series of non-uniform gas flows was then indicated, causing an increase in ESP efficiency. This paper is a review of the gas flow distributions used in ESP and their influence on ESP efficiency. The results of computer analysis presented in this paper show that diversification of gas velocity in the ESP chamber leads to efficiency improvement for shorter zones; however, for longer zones it causes an efficiency drop. The efficiency raise owing to diversification of gas flow profile is a consequence of exponential gas velocity - efficiency dependence.

The paper presents research upon the gas distribution in a physical model and the computer simulation of dust separation in a horizontal electrostatic precipitator (ESP) with a flat inlet diffuser. The research of a gas flow was carried out using the visualization method and the velocity measurement in cross sections of a model chamber. By selecting suitable choking diffusion screens and deflecting vanes in a diffuser the oblique profiles of a gas velocity were obtained for different obliqueness degree. It was assumed that the velocity profiles obtained should guarantee higher performance of an ESP than those uniform profiles as used so far. Those assumptions were proved by the results of computer simulation obtained using a program SYMULA-X. The results of experiments and computer simulation arc presented in a graphical form.