Abstract: In an apparatus for treating an exhaust gas from a diesel engine, including a filter unit in an exhaust gas passage for the diesel engine, the filter unit having a honeycomb structure wherein a plurality of cells are divided by cell walls having a filtration function and extend in the same direction as one another, predetermined cells being closed at one end, and the remaining cells being closed at the other end; the improvement comprises: back washing gas flow generating means for generating a gas flow at appropriate intervals so as to pass through the cell walls in the direction opposite to the flow of the exhaust gas flow, and a recollecting unit for particulates, which is provided in the exhaust gas passage at a position upstream to the filter unit.

Abstract: A filter unit comprises a plurality of plates made of an air-permeable, porous material which define particulate-containing gas passages and clean gas passages. The clean gas passages are formed at one side of each of the air-permeable, porous plates and the particulate-containing gas passages are at the other side in the direction intersecting each other. Particulates in an exhaust gas from a diesel engine deposit and accumulate on the air-permeable, porous plate while the exhaust gas is passed from the particulate-containing gas passages through the air-permeable, porous plates to the clean gas passages. A nozzle is placed in an outlet conduit, which is connected to the discharging side of the clean gas passages, to eject gas for back washing to thereby peel off and drop the particulates on the air-permeable, porous plates. A particulate receiving plate is provided to collect the particulates, which are burnt by a heater provided in the particulate receiving plate.