Internal combustion engine exhaust filter with pressure relief

Abstract

An exhaust filtration system including a gap upstream of the filter and a regular pressure device downstream of the filter to thus normally maintain a pressure differential across the filter but operative to, upon build up of pressure upstream of the filter provide for relief to the atmosphere.

1 . An internal combustion exhaust filtration system for filtering exhaust from an internal combustion engine and comprising:
 a filter for filtering the exhaust;   an exhaust pipe from the engine for flowing the exhaust and terminating in a downstream end;   an inlet pipe having an upstream end and a downstream end connected to the filter;   a pressure release device responsive to the pressure differential between the inlet pipe exceeding a predetermined differential to relieve exhaust flow from the exhaust pipe; and   a pressure reducer for reducing pressure downstream of the pressure relief device.   
   
   
       2 . The exhaust filtration system of  claim 1  wherein:
 the downstream end of the exhaust pipe and the upstream end of the inlet pipe are spaced apart to define the pressure release device.   
   
   
       3 . The exhaust filtration system of  claim 1  wherein:
 the pressure reducer is in the form of a blower downstream of the release device for drawing the exhaust from the device toward the filter.   
   
   
       4 . The exhaust filtration system of  claim 1  wherein:
 the exhaust pipe and inlet pipes are axially aligned.   
   
   
       5 . The exhaust filtration system of  claim 1  wherein;
 one of the pipes is of a larger cross section than the other.   
   
   
       6 . The exhaust filtration system of  claim 1  wherein:
 the pipes are of the same diameter.   
   
   
       7 . The exhaust filtration system of  claim 1  wherein:
 the pressure release device includes at least one connector between the exhaust and inlet pipes.   
   
   
       8 . The exhaust filtration system of  claim 1  wherein:
 the pressure reducer is disposed downstream in the filter.   
   
   
       9 . The exhaust filtration system of  claim 1  wherein:
 the pressure reducer includes a blower downstream for drawing exhaust from the filter.   
   
   
       10 . The filtration exhaust system of  claim 2  wherein:
 the downstream end of the exhaust pipe and upstream end of the inlet pipe are spaced apart a distance of between 1 and two inches.   
   
   
       11 . The filtration exhaust system of  claim 2  wherein:
 the inlet pipe is formed with a larger cross section than the exhaust pipe and the ends of the pipes are spaced apart a distance of at least 1/16 th  of an inch.   
   
   
       12 . The filtration exhaust system of  claim 2  wherein:
 the ends of the pipe are spaced apart at least 1 inch.   
   
   
       13 . The filtration system of  claim 2  that includes:
 a pipe device configured with an opening find the release system  16 .   
   
   
       14 . An internal combustion filtration system for exhausting exhaust from the engine at a normal range of flow and comprising:
 an exhaust system including a filter and a release device upstream of the filter, operative in response to the flow through the filter dropping below the lower end of the range to release flow of exhaust from the exhaust system.   
   
   
       15 . An internal combustion filtration system for exhausting exhaust from an engine and comprising:
 a filter for filtering the exhaust;   a pipe device leading from the engine to the filter and including at least two pipes having ends spaced apart a distance sufficient to, during normal operating conditions effect transfer of a substantial portion of the exhaust flow from the engine to the filter and operative end response to the pressure in the filter building up beyond a predetermined pressure to release exhaust to the atmosphere; and   a pressure reduction device disposed downstream of the pressure release device for reducing the pressure downstream of the pressure release device.   
   
   
       16 . The filtration system of  claim 15  wherein:
 the pipe device includes at least two pipes.   
   
   
       17 . A filtration system of  claim 15  wherein:
 the pressure release device is configured to release exhaust directly to the atmosphere.   
   
   
       18 . The filtration system of  claim 15  wherein:
 the pipe device is constructed to, under normal operation, provide for unobstructed flow to the filter.