Spark ignition engine exhaust system
First Claim
1. An exhaust system for a spark ignition engine on an automotive vehicle comprising:
- filter means disposed downstream of a spark ignition engine for condensing hydrocarbons in exhaust gases from the engine during a first time period after start of the engine;
bypass means for bypassing at least a portion of exhaust gases around said filter means to heat said filter means during a second time period after said first time period and evaporate the condensed hydrocarbons; and
a catalytic converter disposed downstream of said filter means to oxidize the evaporated hydrocarbons and reduce NOx in exhaust gases passing therethrough.
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Accused Products
Abstract
An exhaust system for a spark ignition engine on an automotive vehicle including an exhaust filter disposed downstream of a spark ignition engine for condensing hydrocarbons in exhaust gases from the engine during a first time period after start of the engine, a bypass structure for bypassing at least a portion of exhaust gases around the exhaust-filter to heat the exhaust filter during a second time period after the first time period and evaporate the condensed hydrocarbons, and a catalytic converter disposed downstream of the exhaust filter to oxidize the evaporated hydrocarbons and reduce NOx in exhaust gases passing therethrough. A method is also provided.
57 Citations
20 Claims
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1. An exhaust system for a spark ignition engine on an automotive vehicle comprising:
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filter means disposed downstream of a spark ignition engine for condensing hydrocarbons in exhaust gases from the engine during a first time period after start of the engine; bypass means for bypassing at least a portion of exhaust gases around said filter means to heat said filter means during a second time period after said first time period and evaporate the condensed hydrocarbons; and a catalytic converter disposed downstream of said filter means to oxidize the evaporated hydrocarbons and reduce NOx in exhaust gases passing therethrough. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of reducing hydrocarbons and NOx in an exhaust system for a spark ignition engine on an automotive vehicle, said method comprising the steps of:
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providing a filter downstream of a spark ignition engine and a catalytic converter downstream of the filter for an exhaust system; condensing hydrocarbons in exhaust gases from the engine on the filter during a first time period after start of the engine; bypassing at least a portion of exhaust gases around the filter to heat the filter during a second time period after the first time period and evaporate the condensed hydrocarbons; and oxidizing the evaporated hydrocarbons and reducing NOx in exhaust gases passing through the catalytic converter. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification