Hino Motors, Ltd.

Hitachi Metals, Ltd.

Other

Hiroshi Funabashi

Hirohisa Suwabe

Hisaki Torisaka

Shinya Tokumaru

Yasuhiko Otsubo

Makoto Tsujita

Takashi Takakura

Munetomo Matsunami

Keiichi Nakagome

Satoshi Makita

An apparatus for cleaning an exhaust gas containing nitrogen oxide and particulate matter and discharged from a diesel engine, wherein the apparatus comprises a porous ceramic honeycomb filter and an SCR catalytic converter in this order from upstream, wherein the honeycomb filter has pluralities of flow paths partitioned by porous cell walls and a catalyst supported by the porous cell walls, with desired flow paths sealed by plugs, and wherein at least one plug on the side of an exhaust gas inlet is separate inward from an exhaust gas inlet end. A ratio D/V of the diameter D (mm) of the honeycomb filter to the displacement V (liter) of the diesel engine is preferably 15 mm/liter or more. The honeycomb filter and an SCR catalytic converter are preferably contained in one case.

Exhaust gas-cleaning apparatus

Sensing accuracy of a temperature sensor is enhanced so as to accurately conduct regeneration control of a particulate filter. Disclosed is an exhaust emission control device wherein a pair of dispersion platesandwith a number of communicating holesandare arranged in a filter casingincorporated in an exhaust pipe such that the plates are opposed to each other in a direction of flows of exhaust gas, catalytic regenerative particulate filterbeing received in a reception chamberdefined by and between the dispersion platesand. A temperature sensoris arranged in the filter casingso as to detect exhaust temperature in the reception chamber, a sensing elementof the temperature sensorbeing adapted to be in one of flows of the exhaust gas

Exhaust emission control device

A ceramic honeycomb filter comprising a ceramic honeycomb structure having porous partition walls defining a plurality of flow paths, and plugs disposed inside the flow paths such that an exhaust gas passes through pores of the porous partition walls, thereby removing particulates from the exhaust gas; a catalyst being carried at least partially on the partition walls and/or the plugs; and at least one of plugs on the side of exhaust gas inlets being disposed at a position separate from the inlet-side opening ends of the flow paths. Particulates are removed from the exhaust gas by injecting unburned fuel and/or hydrocarbon in a gaseous state upstream of the inlet-side plugs to maintain at least part of the inlet-side plugs and their downstream regions at a temperature substantially equal to or higher than the lowest activation temperature of the catalyst.

Ceramic honeycomb filter and exhaust gas-cleaning method

A particulate filter integrally carrying an oxidation catalyst is arranged in an exhaust pipe through which exhaust gas from a diesel engine flows. A NO-absorption reduction catalyst is arranged in the exhaust pipe and downstream of the particulate filter. A bypass line is branched from a portion of the exhaust pipe between the particulate filter and the reduction catalyst and is connected to a portion of the exhaust pipe downstream of the reduction catalyst. A selector valve is arranged at the branch point of the bypass line and may be switched over to guide the exhaust gas either to the reduction catalyst or to the bypass line. As a result, without difficultly controlling the operation of the diesel engine, the reduction catalyst is prevented from being poisoned and deteriorated by sulfate, the lowering of the ratio of NOpurification through the NO-absorption reduction catalyst is averted and prolongation of its life is attained.

Exhaust aftertreatment system

Ceramic honeycomb filter

Growing community of inventors

Tokyo, Japan

Hiroshi Funabashi