Claims
- 1. In combination, a heating burner for heating a reactor of an exhaust gas purifying apparatus to operating temperatures, fuel supply means for delivering burner fuel to said heating burner, said fuel supply means including a fuel conduit, 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, and an air control valve, the air control valve including:
- a. a movable valve member situated in said burner air conduit downstream of said air pump; and
- b. regulating means coupling to said movable valve member for regulating the air quantities 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, said regulating means including:
- i. venturi nozzle disposed in said burner air conduit upstream of said movable valve member, said venturi nozzle having a narrowest flow passage section;
- ii. a diaphragm having first and second sides;
- iii. linkage means connecting said diaphragm with said movable valve member;
- iv. means for communicating the pressure prevailing in said narrowest flow passage section with said first side of said diaphragm;
- v. a spring means in engagement with said first side of said diaphragm; and
- vi. means for communicating the pressure prevailing in said burner air conduit downstream of said venturi nozzle and upstream of said movable
- 2. In combination, a heating burner for heating a reactor of an exhaust gas purifying apparatus to operating temperatures, fuel supply means for delivering burner fuel to said heating burner, said fuel supply means including a fuel conduit, a fuel regulating valve having means for setting the throughgoing fuel quantities to a constant value, 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, and an air control valve, with the air control valve including:
- a. a movable valve member situated in said burner air conduit downstream of said air pump; and
- b. regulating means coupled to said movable valve member for regulating the air quantities 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, and with the fuel regulating valve being formed as a diaphragm-type pressure differential valve having:
- a. first and second chambers;
- b. a diaphragm constituting a movable valve member of said pressure differential valve and separating said first and second chambers from one another;
- c. channel means maintaining communication between said first and second chambers; and
- d. adjustable throttle means in said channel means for varying the flow
- 3. The combination as defined in claim 1, wherein said movable valve member
- 4. The combination as defined in claim 1, including:
- a. a solenoid valve in said fuel conduit;
- b. an electric energizing circuit connected to said solenoid valve;
- c. an on-off switch in said electric energizing circuit to close and open the latter; and
- d. means for connecting said diaphragm with said on-off switch, whereby said fuel conduit is shut off by means of said solenoid valve when the air quantities flowing through said burner air conduit fall below a predetermined value.
Priority Claims (1)
| Number |
Date |
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| 2201739 |
Jan 1972 |
DT |
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CROSS REFERENCE TO RELATED APPLICATION
This application is a division of applicant's copending application Ser. No. 322,861 filed on Jan. 11, 1973 now U.S. Pat. No. 3,945,802.
This invention relates to an apparatus for purifying the exhaust gases of internal combustion engines and is of the type which is provided with at least one reactor and a heating burner, both disposed in the exhaust line of the engine, and more particularly to an air control valve used with such an apparatus.
Exhaust gases of internal combustion engines contain, among others, carbon monoxide, oxides of nitrogen and uncombusted or partially combusted hydrocarbons which contribute to a substantial extent to air pollution.
A known exhaust gas purifying apparatus of the aforeoutlined type (such as disclosed, for example, in German Pat. No 470,389) utilizes three measures: first, the exhaust gases are mixed with an oxidizing agent, second, the combustion of the gases is initiated by means of an external heat source and third, the aforenamed combustion is continued and maintained by heat which is derived from the burning gases by means of a catalyzer. This known apparatus comprises a combustion chamber into which leads the exhaust conduit of the engine and an air chamber which surrounds the combustion chamber. Upstream of the combustion chamber in the exhaust conduit there is disposed a catalyzer upstream of which there is arranged a spark plug and an injector which, dependent upon the position of associated valves, selectively draws an air-hydrocarbon mixture or preheated air into the exhaust conduit. When the internal combustion engine is started, the catalyzer is heated over the ignited hydrocarbon mixture. After the combustion chamber has reached a certain temperature that is sufficient to bring the temperature of the air in the air chamber to a predetermined value, the admission of the hydrocarbon mixture is interrupted and the preheated air is mixed to the exhaust gas flow. The harmful pollutants of the latter are then converted with the cooperation of the catalyzer while the catalyzer temperature is maintained.
The ever increasing limitations imposed by law on the poisonous components in the exhaust gas of internal combustion engines require to improve the aforeoutlined heating in such a manner that the period in which the necessary operational temperature of the exhaust gas purifying apparatus is reached, is substantially shortened. This is of great significance because, according to the future test methods the emissions are measured from the time of engine start and the test cycles begin to run as early as the start of the internal combustion engine. Thus, during the warm run of the engine, even the emission of poisonous exhaust gas components by the heating burner are included in the test results.
It is an object of the invention to provide an improved exhaust gas purifying apparatus including an air control valve which produces optimal exhaust gas values as early as the period of the warm-up run of the internal combustion engine.
Briefly stated, according to the invention, the air quantities delivered to the heating burner are adjustable to a constant value by an air control valve independently from the counterpressure at the heating burner and the output of the air pump.
US Referenced Citations (4)
Divisions (1)
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Number |
Date |
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| Parent |
322861 |
Jan 1973 |
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Patent Grant
4009986
