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US3908371A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for supplying fuel to a dual-catalyst exhaust treatment system

Assignee: Nissan Motor Co Ltd
•
Filing: 1972-11-16
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Granted: 1975-09-30
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Expires: 1992-11-16
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Abstract

Abstract A method of and a system for cleaning exhaust gases from engines of motor vehicles, wherein the exhaust gases are passed through reducing and oxidizing catalysts so that nitrogen oxides are reducing in the reducing catalyst and carbon monoxide and hydrocarbons are oxidized in the oxidizing catalyst. The engines are so arranged as to be operable on a relatively thin mixture which is preferably proportioned to provide an excess-air ratio of about 1.0 to 1.15 so that substantially no carbon monoxide and hydrogen are present in the exhaust gases emitted from the engine. A reducing agent such as hydrocarbons is admixed to the exhaust gases entering the reducing catalyst for removing an excess of oxides and reducing the nitrogen oxides in the exhaust gases while secondary air is supplied to the exhaust gases entering the oxidizing catalyst for assisting in the oxidization of the carbon monoxide and hydrocarbons remaining in the exhaust gases passed through the oxidizing catalyst.

Inventors

  • 👤 Tadashi Nagai
  • 👤 Hitoshi Irikura
  • 👤 Kiminobu Sasa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 19:40
CPC Classifications
F; F01; F01N; F01N9/00; B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9459; B01D53/9477; F01N13/00; F01N13/009; F01N3/00; F01N3/08; F01N3/10; F01N3/18; F01N3/20; F01N3/206; F01N3/2066; F01N3/22; F01N3/227; F01N3/24; F01N3/30; F01N3/32; F01N3/36; B01D2251/00; B01D2251/20; B01D2251/208; B01D53/9404; B01D53/9409; B01D53/9413; B01D53/944; F01N2240/00; F01N2240/02; F01N2430/00; F01N2430/06; F01N2470/00; F01N2470/30; F01N2610/00; F01N2610/03; F01N2610/08; F01N2610/10; F01N2610/14; F01N2610/1453; F01N2610/146; F01N2900/00; F01N2900/06; F01N2900/08; F02; F02B; F02B53/00; F02B2053/005; F02D; F02D19/00; F02D19/02; F02D19/021; F02D19/023; F02M; F02M21/00; F02M21/02; F02M21/0203; F02M21/0209; F02M21/0212; F02M21/04; F02M21/047; F02M21/06; F02M25/00; F02M25/08; F02M25/089; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y02T10/40; Y10; Y10S; Y10S60/00; Y10S60/90

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 307 words
A COMBINATION WITH A MOTOR VEHICLE ENGINE WHICH IS ADAPTED TO BE OPERATED ON AN AIR-FUEL MIXTURE PROPORTIONED TO AN AIR-TO-FUEL RATIO IN A RANGE BETWEEN A STOICHIOMETRIC AIR- TOFUEL RATIO AND A VALUE APPRECIABLY HIGHER THAN THE STOICHIOMETRIC-TO-FUEL RATIO IN A RANGE BETWEEN A STOICHIOMETRIC AIR-TOPRISES REDUCING AN OXIDIZING CATALYST MEANS WHICH ARE INCORPORATED IN AN EXHAUST SYSTEM OF SAID ENGINE, SAID OXIDIZING CATALYST MEANS BEING LOCATED POSTERIOR TO SAID REDUCING CATALYST MEANS, REDUCING AGENT SUPPLY MEANS FOR SUPPLYING A REDUCING AGENT TO SAID EXHAUST SYSTEM UPSTREAM OF SAID REDUCING CATALYST MEANS FOR REMOVING AN EXCESS OF OXYGEN AND REDUCING NITROGEN OXIDES IN THE EXHAUST GASES PASSED THROUGH SAID REDUCING CATALYST MEANS, SAID REDUCING AGENT SUPPLY MEANS INCLUDING FUEL STORAGE MEANS RECEIVING A FUEL FROM A FUEL TANK OF SAID ENGINE, AND FUEL EVAPORATOR MEANS FOR EVAPORATING THE FUEL DELIVERED FROM SAID FUEL STORAGE MEANS AND FEEDING THE RESULTANT EVAPORATED FUEL TO SAID EXHAUST SYSTEM UPSTREAM OF SAID REDUCING XATALYST MEANS, SAID FUEL EVAPORATOR MEANS INCLUDING A FUEL EVAPORATING CHAMBER HAVING AN IN LET COMMUNICATING WITH SAID FUEL STORAGE MEANS AND AN OUTLET COMMUNICATING WITH SAID EXHAUST SYSTEN UPSTREAM OF SAID REDUCING CATALYST MEANS AND A HEATING CHAMBER WHICH IS IN CONTACT WITH SAID FUEL EVAPORATING CHAMBER AND WHICH HAS AN INLET AND OUT LET COMMUNICATING RESPECTIVELY WITH SAID EXHAUST SYSTEM UPSTREAM AND DOWNSTREAM OF AN OUTLET OF A PIPELINE LEADING FROM THE OUTLET OF SAID FUEL EVAPORATING CHAMBER FOR HEATING AND EVAPORATING THE LIQUID FUEL IN SAID FUEL EVAPORATING CHAMBER BY TRANSFER OF HEAT TO SAID FUEL EVAPORATING CHAMBER FROM THE HOT EXHAUST GASES CIRCULATED TROUGH SAID HEATING CHAMBER, AND OXIDIZING CATALYST MEANS FOR SUPPLYING SECONDARY AER T TE EXHAUST SYSTEM INTERVENING BETWEEN SAID REDUCING AND OXIDIZING CATALYST MEANS FOR OXICIZING XARBON MONOXIDE AND HYDROCARBONS IN THE EXHAUST SYSTEM PASSED THROUGH THE OXIDIZING CATALYST MEANS.
Claim 2
Dependent Claim 307 words
A COMBINATION WITH A MOTOR VEHICLE ENGINE WHICH IS ADAPTED TO BE OPERATED ON AN AIR-FUEL MIXTURE PROPORTIONED TO AN AIR-TO-FUEL RATIO IN A RANGE BETWEEN A STOICHIOMETRIC AIR- TOFUEL RATIO AND A VALUE APPRECIABLY HIGHER THAN THE STOICHIOMETRIC-TO-FUEL RATIO IN A RANGE BETWEEN A STOICHIOMETRIC AIR-TOPRISES REDUCING AN OXIDIZING CATALYST MEANS WHICH ARE INCORPORATED IN AN EXHAUST SYSTEM OF SAID ENGINE, SAID OXIDIZING CATALYST MEANS BEING LOCATED POSTERIOR TO SAID REDUCING CATALYST MEANS, REDUCING AGENT SUPPLY MEANS FOR SUPPLYING A REDUCING AGENT TO SAID EXHAUST SYSTEM UPSTREAM OF SAID REDUCING CATALYST MEANS FOR REMOVING AN EXCESS OF OXYGEN AND REDUCING NITROGEN OXIDES IN THE EXHAUST GASES PASSED THROUGH SAID REDUCING CATALYST MEANS, SAID REDUCING AGENT SUPPLY MEANS INCLUDING FUEL STORAGE MEANS RECEIVING A FUEL FROM A FUEL TANK OF SAID ENGINE, AND FUEL EVAPORATOR MEANS FOR EVAPORATING THE FUEL DELIVERED FROM SAID FUEL STORAGE MEANS AND FEEDING THE RESULTANT EVAPORATED FUEL TO SAID EXHAUST SYSTEM UPSTREAM OF SAID REDUCING XATALYST MEANS, SAID FUEL EVAPORATOR MEANS INCLUDING A FUEL EVAPORATING CHAMBER HAVING AN IN LET COMMUNICATING WITH SAID FUEL STORAGE MEANS AND AN OUTLET COMMUNICATING WITH SAID EXHAUST SYSTEN UPSTREAM OF SAID REDUCING CATALYST MEANS AND A HEATING CHAMBER WHICH IS IN CONTACT WITH SAID FUEL EVAPORATING CHAMBER AND WHICH HAS AN INLET AND OUT LET COMMUNICATING RESPECTIVELY WITH SAID EXHAUST SYSTEM UPSTREAM AND DOWNSTREAM OF AN OUTLET OF A PIPELINE LEADING FROM THE OUTLET OF SAID FUEL EVAPORATING CHAMBER FOR HEATING AND EVAPORATING THE LIQUID FUEL IN SAID FUEL EVAPORATING CHAMBER BY TRANSFER OF HEAT TO SAID FUEL EVAPORATING CHAMBER FROM THE HOT EXHAUST GASES CIRCULATED TROUGH SAID HEATING CHAMBER, AND OXIDIZING CATALYST MEANS FOR SUPPLYING SECONDARY AER T TE EXHAUST SYSTEM INTERVENING BETWEEN SAID REDUCING AND OXIDIZING CATALYST MEANS FOR OXICIZING XARBON MONOXIDE AND HYDROCARBONS IN THE EXHAUST SYSTEM PASSED THROUGH THE OXIDIZING CATALYST MEANS.
Claim 3
Dependent Claim 235 words
A combination with a motor vehicle engine which is adapted to be operated on an air-fuel mixture propoRtioned to an air-to-fuel ratio in a range between a stoichiometric air-to-fuel ratio and a value appreciably higher than the stoichiometric air-to-fuel ratio, of an exhaust cleaning system which comprises reducing and oxidizing catalyst means which are incorporated in an exhaust system of said engine, said oxidizing catalyst means being located posterior to said reducing catalyst means, reducing agent supply means for supplying a reducing agent to said exhaust sytem upstream of said reducing catalyst means for removing an excess of oxygen and reducing nitrogen oxides in the exhaust gases passed through said reducing catalyst means, said reducing agent supply means including fuel storage means receiving a fuel from a fuel tank of said engine and fuel evaporator means for evaporating the fuel delivered from said fuel storage means and feeding the resultant evaporated fuel to said exhaust system upstream of said reducing catalyst means, said fuel evaporator means including a pipeline leading from the exhaust system for feeding the hot exhaust gases into the liquid fuel in said fuel storage means for evaporating the fuel by a vapor pressure thereof, and secondary air supply means for supplying secondary air to the exhaust system intervening between said reducing and oxidizing catalyst means for oxidizing carbon monoxide and hydrocarbons in the exhaust system passed through the oxidizing catalyst means.
Claim 4
Dependent Claim 235 words
A combination with a motor vehicle engine which is adapted to be operated on an air-fuel mixture propoRtioned to an air-to-fuel ratio in a range between a stoichiometric air-to-fuel ratio and a value appreciably higher than the stoichiometric air-to-fuel ratio, of an exhaust cleaning system which comprises reducing and oxidizing catalyst means which are incorporated in an exhaust system of said engine, said oxidizing catalyst means being located posterior to said reducing catalyst means, reducing agent supply means for supplying a reducing agent to said exhaust sytem upstream of said reducing catalyst means for removing an excess of oxygen and reducing nitrogen oxides in the exhaust gases passed through said reducing catalyst means, said reducing agent supply means including fuel storage means receiving a fuel from a fuel tank of said engine and fuel evaporator means for evaporating the fuel delivered from said fuel storage means and feeding the resultant evaporated fuel to said exhaust system upstream of said reducing catalyst means, said fuel evaporator means including a pipeline leading from the exhaust system for feeding the hot exhaust gases into the liquid fuel in said fuel storage means for evaporating the fuel by a vapor pressure thereof, and secondary air supply means for supplying secondary air to the exhaust system intervening between said reducing and oxidizing catalyst means for oxidizing carbon monoxide and hydrocarbons in the exhaust system passed through the oxidizing catalyst means.
Claim 5
Dependent Claim 232 words
A combination with a motor vehicle engine which is adapted to be operated on an air-fuel mixture proportioned to an air-to-fuel ratio in a range between a stoichiometric air-to-fuel ratio and a value appreciably higher than the stoichiometric air-to-fuel ratio, of an exhaust cleaning system which comprises reducing and oxidizing catalyst means which are incorporated in an exhaust system of said engine, said oxidizing catalyst means being located posterior to said reducing catalyst means, reducing agent supply means for supplying a reducing agent to said exhaust system upstream of said reducing catalyst means for removing an excess of oxygen and reducing nitrogen oxides in the exhaust gases passed through said reducing catalyst means, said reducing agent supply means including a source of liquefied petroleum gas, evaporator means for evaporating the liquefied petroleum gas from said source, pumping means for delivering the resultant evaporated petroleum gas to the exhaust system upstream of said reducing catalyst means, and a flow control valve intervening between said pumping means and said exhaust system for controlling the rate of flow of the evaporated petroleum gas to be passed to the exhaust system in accordance with driving conditions of the engine, and secondary air supply means for supplying secondary air to the exhaust system intervening between said reducing and oxidizing catalyst means for oxidizing carbon monoxide and hydrocarbons in the exhaust system passed through the oxidizing catalyst means.
Claim 6
Dependent Claim 232 words
A combination with a motor vehicle engine which is adapted to be operated on an air-fuel mixture proportioned to an air-to-fuel ratio in a range between a stoichiometric air-to-fuel ratio and a value appreciably higher than the stoichiometric air-to-fuel ratio, of an exhaust cleaning system which comprises reducing and oxidizing catalyst means which are incorporated in an exhaust system of said engine, said oxidizing catalyst means being located posterior to said reducing catalyst means, reducing agent supply means for supplying a reducing agent to said exhaust system upstream of said reducing catalyst means for removing an excess of oxygen and reducing nitrogen oxides in the exhaust gases passed through said reducing catalyst means, said reducing agent supply means including a source of liquefied petroleum gas, evaporator means for evaporating the liquefied petroleum gas from said source, pumping means for delivering the resultant evaporated petroleum gas to the exhaust system upstream of said reducing catalyst means, and a flow control valve intervening between said pumping means and said exhaust system for controlling the rate of flow of the evaporated petroleum gas to be passed to the exhaust system in accordance with driving conditions of the engine, and secondary air supply means for supplying secondary air to the exhaust system intervening between said reducing and oxidizing catalyst means for oxidizing carbon monoxide and hydrocarbons in the exhaust system passed through the oxidizing catalyst means.

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-09-29 1979-03-31 1979-09-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-09-29 1983-03-31 1983-09-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-09-29 1987-03-31 1987-09-30 $7700.00 Window Closed / Lapsed

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