Internal combustion engine exhaust gas treatment apparatus and method

Claim 2

The exhaust gas treatment apparatus of claim 2 wherein said means for oxidation of the exhaust gas additionally includes means for sensing the temperature of the exhaust gas within said means for oxidation of the exhaust gas and for selectively controlling admission of fuel into said oxidation means in response to said temperature.

Claim 3

The exhaust gas treatment apparatus of claim 3 wherein said means for oxidation of the exhaust gas additionally includes second means for controlling the admission of fuel flow in response to the admission of air into said oxidation means.

Claim 4

The exhaust gas treatment apparatus of claim 3 wherein said means for sensing temperature and controlling fuel flow admits fuel when the exhaust gas temperature within said means for oxidation of the exhaust gas is less than 1,400* F.

Claim 5

An exhaust gas treatment apparatus for use with an internal combustion engine discharging exhaust gas containing nitrogen oxides, carbon monoxide, and hydrocarbons, comprising: means for oxidation of the hydrocarbons and carbon monoxide in the exhaust gas including a housing having inlet and outlet means, means for admitting air, ignition means; said means for admitting air comprising a turbine-compressor, a compressed air conduit interconnecting said compressor and said oxidation means housing, vacuum selector valve means, a vacuum line interconnecting the engine intake manifold and the valve means, an auxiliary vacuum source, a second vacuum line interconnecting said auxiliary vacuum source and said valve means, and a third vacuum line interconnecting said valve means and said turbine, whereby said turbine-compressor is driven by a vacuum from the engine intake manifold or the auxiliary vacuum source as selected by said vacuum selector valve means.

Claim 6

An exhaust gas treatment apparatus for use with an internal combustion engine having an intake manifold, a carburetor, and an exhaust manifold, the engine discharging exhaust gas through the exhaust manifold, the exhaust gas including carbon monoxide, nitrogen oxides, and hydrocarbons, comprising: nitrogen oxides reduction means, including a housing having inlet and outlet means, said inlet means in fluid communication with the engine exhaust manifold, and a reduction zone a plurality of heat exchanger tubes supported in said housing, a catalyst supported by said heat exchanger tubes for facilitating reduction of the nitrogen oxides by the carbon monoxide in the exhaust gas, whereby the exhaust gas and said catalyst are heated by said heat exchanger to a temperature sufficient to sustain effective reduction; and carbon monoxide and hydrocarbon oxidation means, including a housing having inlet and outlet means, said inlet means in fluid communication with the outlet means of said nitrogen oxides reduction means housing, and said outlet means in fluid communication with said heat exchanger tubes for providing hot oxidized gases thereto, the other end of said tubes being open to atmosphere, and an oxidizing zone, ignition means, fuel supply means, valve means for controlling fuel flow into said oxidizing zone, means for supplying and admitting air to said oxidizing zone, first means for controlling said fuel flow valve means in response to the temperature in said oxidizing zone, second means for controlling said fuel flow valve means in response to the admission of air into said oxidizing zone, whereby air and fuel are combusted in said oxidizing zone when said exhaust gas received from said nitrogen oxides reduction means is at a temperature insufficient to sustain effective oxidation of the carbon monoxide and hydrocarbons in the exhaust gas.

Claim 7

The exhaust gas treatment apparatus of claim 7 wherein said means for supplying and admitting air to said oxidizing zone comprises: a turbine-compressor; a compressed air conduit interconnecting said compressor and said oxidation means housing; vacuum selector valve means; a vacuum line interconnecting the engine intake manifold and the valve means; an auxiliary vacuum source; a second vacuum line interconnecting said auxiliary vacuum source and said valve means; and a third vacuum line interconnecting said valve means and said turbine.

Claim 8

The exhaust gas treatment apparatus of claim 8 wherein said auxiliary vacuum source includes a converging-diverging nozzle supported by the engine carburetor and including a venturi section having an opening in fluid communication with said second vacuum line interconnecting said auxiliary vacuum source and said valve means.

Claim 9

The exhaust gas treatment apparatus of claim 7 additionally including safety means for preventing the admission of exhaust gas into said nitrogen oxides reduction means and said carbon monoxide and hydrocarbon oxidation means when the exhaust gas discharge from the engine exceeds a preselected temperature, including: valve means having an inlet in fluid communication with the engine exhaust manifold, a first outlet in fluid communication with the inlet means of said nitrogen oxides reduction means, and a second outlet open to the atmosphere, control means for said valve means to concurrently open one of said valve means outlets and close the other of said valve means outlets, and means for selective operation of said valve control means in response to the exhaust gas temperature in said oxidizing zone.

Claim 10

In an exhaust gas treatment apparatus for use with an internal combustion engine discharging exhaust gas, containing nitrogen oxide, carbon monoxide and hydrocarbons, said apparatus having inlet means for receiving the exhaust gas, means for a catalytic reduction of the nitrogen oxide in the presence of carbon monoxide in the exhaust gas, said catalytic reduction means being located in fluid communication with the inlet means to receive the exhaust gas therefrom, means for oxidation of the carbon monoxide and hydrocarbons in the exhaust gas, said oxidation means being located in fluid communication with and downstream of the catalytic reduction means, to receive the exhaust gas from the catalytic reduction means, and outlet means for discharging the exhaust gas from the apparatus, the improvement comprising: means for heating the catalyst disposed within said catalytic reduction means and located to receive the gas from the oxidation means and to pass the gas through the catalyst.