Exhaust gas purifying apparatus
AssigneeRobert Bosch GmbH
InventorKonrad Eckert
Life of this patent
Estimating the term…
Abstract
In an exhaust gas purifying apparatus which includes first and second reactors in the exhaust line of an internal combustion engine there is provided a heater burner to which there is delivered an air-fuel mixture and which heats the first reactor for rapidly bringing it to operating temperatures when the engine is started. In the air conduit through which combustion air for the air-fuel mixture is delivered to the burner there is provided a valve controlled in such a manner that the flow rate of combustion air remains constant and is thus independent of the counterpressure at the heating burner and the output delivery of the air pump driving the combustion air. Upon reaching operating temperatures the burner is extinquished and the combustion air is rerouted past the first reactor to the second reactor.
Claims6
In an exhaust gas purifying apparatus for treating the exhaust gases in the exhaust line of the internal combustion engine, said apparatus being of the type that has (a) a reactor in said exhaust line, (b) a heating burner for heating said reactor to operating temperatures, (c) fuel supply means for delivering burner fuel to said heating burner, said fuel supply means including a fuel conduit, (d) air supply means for delivering combustion air to said heating burner, said air supply means including a burner air conduit and an air pump disposed in the latter, the improvement comprising an air control valve including:
- A. a movable valve member situated in said burner air conduit downstream of said air pump;
- B. flow regulating means coupled to said movable valve member for regulating the air quantity delivered to said heating burner to a constant value independently from the counterpressure at said heating burner and independently from the output delivery of said air pump;
- C. an additional reactor in said exhaust line;
- D. an intermediate pipe forming part of said exhaust line and extending between said reactors;
- E. a secondary air conduit extending from said burner air conduit to said intermediate pipe and opening in the direction of said additional reactor;
- F. a routing valve in said burner air conduit between said air control valve and said air pump, said routing valve being connected to said secondary air conduit, said routing valve having a first position in which communication is maintained between said air pump and said air control valve and communication is blocked between said air pump and said secondary air conduit and a second position in which communication is mantained between said air pump and said secondary air conduit and communication is blocked between said air pump and said air control valve;
- and
- G. a temperature sensor connected to said routing valve and responsive to the temperature of the reactor associated with said heating burner, said temperature sensor causing said routing valve to be moved from said first position to said second position when the reactor associated with said heating burner reaches its operating temperature.
Dependencies are inferred from the claim text.