Cool exhaust recycling

Claim 2

In an internal combustion engine, A. an inlet conduit for conducting a fuel-air mixture into said engine for combustion therein, B. an exhaust conduit for discharging hot exhaust gases from said engine, C. an exhaust muffler having 1. a flow path in communication with said exhaust conduit to receive said exhaust gases and conduct the same through said muffler, and 2. means for providing a source of comparatively cool exhaust gases with respect to the temperature of the exhaust gases in said flow path comprising baffle means defining a sound attenuating chamber off said flow path and in communication therewith, and D. means for effectively inhibiting the formation of noxious oxides of nitrogen during said combustion by limiting the temperature thereof comprising restricted bypass duct means having 1. one end opening into said chamber to receive said cool exhaust gases, and 2. a second end opening into said inlet conduit to discharge said cool exhaust gases thereinto.

Claim 3

means for providing a source of comparatively cool exhaust gases with respect to the temperature of the exhaust gases in said flow path comprising baffle means defining a sound attenuating chamber off said flow path and in communication therewith, and D. means for effectively inhibiting the formation of noxious oxides of nitrogen during said combustion by limiting the temperature thereof comprising restricted bypass duct means having

Claim 4

means for providing a source of comparatively cool exhaust gases with respect to the temperature of the exhaust gases in said flow path comprising baffle means defining a sound attenuating chamber off said flow path and in communication therewith, and D. means for effectively inhibiting the formation of noxious oxides of nitrogen during said combustion by limiting the temperature thereof comprising restricted bypass duct means having

Claim 5

a second end opening into said inlet conduit to discharge said cool exhaust gases thereinto.

Claim 6

a second end opening into said inlet conduit to discharge said cool exhaust gases thereinto.

Claim 7

In the combination according to claim 1, said chamber having an exterior surface in heat exchange relationship with the atmosphere.

Claim 8

cooling the exhaust gases within said chamber sufficiently to solidify a major proportion of lead contaminants therein, and

Claim 9

cooling the exhaust gases within said chamber sufficiently to solidify a major proportion of lead contaminants therein, and

Claim 10

recycling a portion of the cooled exhaust gases from said chamber by metering the later gases through a metering restriction into the air inlet for said engine to reduce the formation of nitrogen oxides.

Claim 11

recycling a portion of the cooled exhaust gases from said chamber by metering the later gases through a metering restriction into the air inlet for said engine to reduce the formation of nitrogen oxides.

Claim 12

In the combination according to claim 2, said chamber being dimensioned and said opening of said one end of said bypass duct means into said chamber being located with respect to the location of the communication between said chamber and flow path to maintain the cool exhaust gases flowing from said chamber at temperatures between approximately 500* F and 700* F.

Claim 13

In the combination according to claim 1, said second end of said bypass duct means extending through the sidewall of said inlet conduit, and means for insulating the exhaust gas flowing in said bypass duct means from the heat of said inlet conduit.

Claim 14

In the combination according to claim 1, said inlet conduit having a venturi restriction therein, and said second end of said bypass duct means opening into said inlet conduit at the region of said venturi restriction to modulate the flow of said cool exhaust gases in said bypass duct means as a function of the gas flow through said venturi restriction.

Claim 15

In the combination according to claim 5, said second end of said bypass duct means extending through the sidewall of said inlet conduit at the region of said venturi restriction, and means for insulating the exhaust gas flowing through said bypass duct means from the heat of said inlet conduit.

Claim 16

In the combination according to claim 5, throttle valve means in said inlet conduit movable between idle and wide open positions, and control valve means in said bypass duct means for controlling the flow of said cool exhaust gases therein and responsive to the position of said throttle valve means for restricting the latter flow when said throttle valve means is at said idle and wide open positions.

Claim 17

In the combination according to claim 7, said control valve means including a control valve element movable to vary the restriction of said bypass duct means, a pressure actuated diaphragm operably coupled with said control valve element, and a pressure sensing duct operably connecting said inlet conduit and diaphragm to actuate said control valve element in accordance with the pressure in said inlet conduit.

Claim 18

In the combination according to claim 8, the restriction in said bypass duct means comprising a control orifice having a predetermined dimension and being located upstream of said control valve element.

Claim 19

In the combination according to claim 8, said throttle valve means comprising a throttle blade pivotal within said inlet conduit at a location downstream of said venturi restriction and having a leading edge movable in an upstream direction upon opening movement of said throttle blade from its idle position, resilient means yieldingly urging said control valve element to restrict said bypass duct means, the coupling between said diaphragm and control valve element comprising means for urging the latter in opposition to said resilient means to open said bypass duct means upon the application of low pressure to one side of said diaphragm, said pressure sensing duct having one end opening into said inlet conduit at a location adjacent said leading edge and within a high pressure region of said inlet conduit when said throttle blade is at its idle position, said leading edge being movable upstream of the latter location to reduce the pressure thereat throughout a limited range of opening movement of said throttle blade from said idle position, a second end of said pressure sensing duct being in communication with said one side of said diaphragm to apply thereto the pressure at said one end of said pressure sensing duct.

Claim 20

In the combination according to claim 10, the restriction in said bypass duct means comprising a control orifice having a predetermined dimension and being located upstream of said control valve element.

Claim 21

In the method of operating an internal combustion engine utilizing leaded fuel, the steps of

Claim 22

In the method of operating an internal combustion engine utilizing leaded fuel, the steps of

Claim 23

In the method according to claim 12, restricting the recycling flow of said cooled gases when said engine is operating at either idle or wide open throttle conditions.

Claim 24

In the method according to claim 12, wherein said inlet includes a venturi restriction, the additional step of modulating the recycling flow of said cooled gases in accordance with the flow of inlet gases within said inlet by introducing the cooled gases into said inlet at the region of said venturi restriction.

Claim 25

In the method according to claim 14, restricting the recycling flow of said cooled gases when said engine is operating at either idle or wide open throttle conditions.

Claim 26

In the method of claim 12, said step of cooling the exhaust gases comprising cooling said gases to less than 700* F.

Claim 27

In the method of claim 12, the step of cooling said exhaust gases comprising cooling said gases within said chamber to between 550* F. and 700* F.

Claim 28

In the method of claim 17, the step of recycling a portion of the cooled exhaust gases into said inlet comprising conducting the last named portion via a fixed metering restriction into said inlet at temperatures between 200* F. and 700* F.

Claim 29

In the method of claim 17, wherein said inlet includes a venturi restriction, the step of recycling a portion of the cooled exhaust gases into said inlet comprising conducting the last named portion via said metering restriction into said inlet at the region of said venturi restriction at temperatures between 200* F. and 700* F.