Soot or carbon black is particles of carbon that produce from incomplete combustion of hydrocarbons. Soot has a direct impact on human respiration and is the main cause of many respiratory and cancerous diseases. It is produced from several sources that the most important source is diesel engines. Nowadays, Diesel Particulate Filter (DPF) is widely used in the world as an obligatory tool with diesel vehicles. Among particulate filters, electrostatic filters are mostly considered because of their low-pressure loss and not increasing the fuel consumption. In these filters, suspended particles are charged by an electric discharge and then collected by an electric field on a counter. In this thesis, firstly the initial designs of the electrostatic filter for soot were evaluated and based on their existing problems, several new consecutive designs were constructed and examined. In All designs, for better control, the charging part was separated from the collection unit. In the first design, a small metal tube with a diameter of 2 cm and a length of 1 m was placed in the center of a larger metal tube with a diameter of 5 cm and a length of 1.5 meters. The tubes acted as the collector, and were connected to a separate power supply. The corona needle was mounted in the center of the larger tube, at a 5 cm distance from the smaller tube. The test result showed that carbon powder was well absorbed on the inner tube. Subsequently, by increasing the diameter of the tubes and reversing the soot charging path, it was practically tested on a minibus but it was not successful. Regarding the huge amount of the soot and exhaust exit gas, the problems were; low charging power and collection efficiency. Hence, it was redesign with many parallel and closing plates for the collector and changing the discharge geometry to wire, rather than needle, for higher ion current. This performance of the design was very good for iron oxide particles as well as carbon powder. Based on these results, the final electrostatic DPF was designed for a minibus.
