抄録
The authors have newly developed an Electrostatic Cyclone DPF to reduce PM emission in diesel exhaust. The PM collection test with the DPF was investigated using two types of marine diesel engines, i.e., a low speed two-stroke engine (3UEC37LA, 1105 kW, 188 rpm) and a high speed four-stroke engine （3L13AHS, 74 kW, 1200 rpm）. Two types of fuels, MDO with a sulfur content of 0.07 % and HFO with a sulfur content of 2.2 %, were used for the tests.
The results of the tests are as follows: (1) The Electrostatic Cyclone DPF can reduce PM emission by over 90 %. The DPF has high collection efficiency not only for soot but also for sulfate and soluble organic fraction (SOF) in PM. (2) The PM collection efficiency for HFO was higher than that for MDO; therefore it was confirmed that the DPF is applicable to marine diesel engines operated with HFO. (3) The majority of the PM particles have diameters less than 500nm, and the PM collection efficiency for particles smaller than 100nm is greater than 95 %. (4) An exhaust gas processing system which can reduce PM, SOx and NOx is realized by application of the DPF. The proposed exhaust gas processing system consists of the DPF, the scrubber and the EGR system.
