Diesel exhaust treatment apparatus

Abstract

Apparatus for attenuating particulate matter and volatile organic compounds in exhaust gases of diesel engines. The apparatus includes a housing disposed serially relative to exhaust gas flow. The housing encloses mechanical filters having gas orifices of different sizes, and after the filters, a low temperature, low restriction catalytic converter. Pressure may be monitored to infer clogging by particulates. Clogging may be annunciated by an indicating light. Individual filters may be contained within plural separate filter canisters, which may be removed for cleaning. The housing may be substantially of aluminum, having cooling fins and a longitudinally oriented mounting foot. Filters may be arranged such that their orifices are misaligned to promote separation of particulates from the exhaust gases.

1 . Apparatus for attenuating particulate matter in the exhaust of a diesel engine, comprising:
 a housing having a circumferential wall, a longitudinal axis, an inlet end, and an outlet end; and   a plurality of filter canisters each containing mechanical filters having exhaust gas passage orifices, disposed serially within the housing, and wherein the exhaust gas passage orifices of the mechanical filters are of at least two different orifice sizes.   
     
     
         2 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , wherein within each one of the filter canisters, the mechanical filters contained therein are arranged in a random order. 
     
     
         3 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , wherein the mechanical filters contained within each said filter canister are spaced apart from one another. 
     
     
         4 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , wherein the exhaust gas passage orifices of any one of the mechanical filters are out of linear registry with the exhaust gas passage orifices of an adjacent mechanical filter. 
     
     
         5 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , wherein the housing comprises a metallic composition substantially of aluminum. 
     
     
         6 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , wherein the filter canisters and the mechanical filters are metallic and are disposed in heat transfer relation to the housing. 
     
     
         7 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , wherein the housing comprises a plurality of external cooling fins. 
     
     
         8 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , wherein the housing has conical configuration and an open interior at the inlet end, whereby at least some separation of particulate matter from exhaust flowing through the apparatus occurs at the inlet end of the housing. 
     
     
         9 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , wherein the housing comprises a mounting flange extending in the longitudinal direction. 
     
     
         10 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , wherein the housing is cylindrical and the mounting flange presents a planar surface away from the housing, and the mounting flange is generally tangential to the housing. 
     
     
         11 . The apparatus for attenuating particulate matter and in the exhaust of a diesel engine of  claim 1 , further comprising a pressure sensing arrangement which may be used to determine by inference whether the apparatus for attenuating particulate matter and volatile organic compounds in the exhaust of a diesel engine has become clogged by particulate matter which has been separated from the exhaust gases. 
     
     
         12 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 11 , wherein determination of clogging by the pressure sensing arrangement utilizes one pressure sensor, and is based on a threshold of a single predetermined pressure value being exceeded. 
     
     
         13 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 11 , wherein determination of clogging by the pressure sensing arrangement utilizes a first pressure sensor disposed to sense exhaust gas pressures proximate the inlet end and a second pressure sensor disposed to sense exhaust gas pressures proximate the outlet end, and wherein determination of clogging by the pressure sensing arrangement is based on a threshold of a differential in pressures sensed by the first pressure sensor and the second pressure sensor being exceeded. 
     
     
         14 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 11 , further comprising an alarm arrangement which is disposed to signal an alarm condition responsive to determining that the filter is clogged. 
     
     
         15 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 11 , wherein the alarm arrangement comprises an indicating light. 
     
     
         16 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , further comprising a catalytic converter disposed serially within the housing on that side of the mechanical filters which is proximate the outlet end. 
     
     
         17 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 16 , wherein the catalytic converter is a low temperature, low restriction type. 
     
     
         18 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 16 , wherein the housing comprises a first section enclosing the filter canisters, a second section enclosing the catalytic converter, and a connecting conduit disposed to connect the first section to the second section, wherein the first section has a first diameter, the second section has a second diameter, and the connecting conduit has a third diameter which is less in magnitude than the first diameter and the second diameter. 
     
     
         19 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , wherein the number of filter canisters containing mechanical filters is four. 
     
     
         20 . The apparatus for attenuating particulate matter in the exhaust of a diesel engine of  claim 1 , wherein the exhaust gas passage orifices of the mechanical filters are of four different orifice sizes.