Abstract: A multi-stage honeycomb heater includes: at least two honeycomb heaters electrically connected with each other and disposed along a stream of fluid; the two honeycomb heaters including furthest upstream honeycomb heater and a an adjacent honeycomb heater which is adjacent to and downstream of the furthest upstream honeycomb heater; each of the two honeycomb heaters having an electrically conductive honeycomb structure the honeycomb structure of the upstream honeycomb heater having slits for adjusting its electrical resistance and/or element for adjusting heat capacity of the honeycomb structure so that the ratio of applied power to heat capacity of the furthest upstream honeycomb heater is larger than the ratio of applied power to heat capacity of the adjacent honeycomb heater. Thus the upstream heater and the downstream heater can give similar temperature increases without a temperature distribution along a flow direction during the engine warm-up.

Abstract: An exhaust gas purification device comprising a three way catalyst, an oxidizing catalyst and a NOx absorbent which are arranged in this order in the exhaust passage. A rich air-fuel mixture is burned in the combustion chamber, and the exhaust gas discharged from the engine is initially introduced into the three way catalyst. Secondary air is fed into the exhaust passage between the three way catalyst and the oxidizing catalyst so that the air-fuel ratio of the exhaust gas flowing into the oxidizing catalyst and the NOx absorbent becomes lean.

Abstract: An apparatus for introducing fresh air into an exhaust pipe of an internal combustion engine for purification of exhaust gas includes an air introducing means disposed between an intake pipe and an exhaust pipe of an internal combustion engine for introducing a fresh air into the exhaust pipe and hence to a catalytic converter, and a heater for heating the fresh air introduced through the air introducing means, wherein the heated air is fed to an catalytic converter via the exhaust pipe. Conversion of noxious components contained in the exhaust gas into harmless components is attained with the enhanced efficiency owing to heating of the fresh air by the heating means.

Abstract: An exhaust gas purification system having a catalyst for removing nitrogen oxides from exhaust gas causes the temperature range of activation of the catalyst to shift toward the higher temperature side when the degree of oxidation of the catalyst becomes pronounced.

Abstract: Exhaust gas cleaner system for an automotive internal combustion engine includes an air introduction pipe 8 for introducing secondary air, heated initially by a heater 23, to the catalytic converter unit 7 mounted on the exhaust pipe 3. The ignition timings of the engine is retarded at least during the time when the secondary air is heated by the heater 23. Preferably, the number of ignition timings are counted by a counter modulo 5, for example, in the case of a four-cylinder engine, and the ignition timings are retarded when the counter content is 3 or 4, such that the ignition timings of the cylinders are retarded intermittently. Alternatively, the retardation of the ignition timings may be terminated before the introduction of the heated secondary air is terminated.Where two first and second catalytic converter units 7a and 7b are provided, secondary air distributed by a change-over valve 10a is heated separately by heaters 23b and 23c.

Abstract: A pre-heating arrangement for a catalytic converter of an internal combustion engine having a pre-heating burner operated according to a control and regulation program in the cold-running state of the internal combustion engine after start up. The catalytic converter (2) is formed by two converter elements (4, 5) between which is a converter chamber (6). Hot gases from the burner enter the converter chamber (6) and mix thereat with the exhaust gas from the internal combustion engine and heat the converter element (5) which is second in line in the direction of engine exhaust gas flow. The first converter element (4) on the upstream side, which is subject to impairment due to aging, is by-passed by the hot gases from the burner, which are thereby employed efficiently to rapidly bring the second catalytic converter element (5) up to operating temperature.

Abstract: Apparatus for the cleaning of fluid moving along a path of travel comprising a first container having a longitudinal axis, the container having an input end for the receipt of the fluid to be purified, an output end for the discharge of the cleaned fluid and sequential zones therebetween; an input zone within the container located adjacent to the input end with an ozone injector operatively associated with the input end followed by first isolation chambers in the input zone for the passage therethrough of ozone and fluid being cleaned, the first isolation chambers having fins defining channels located along the axis of the container; an output zone within the container located adjacent to the output end, the output zone including second isolation chambers for the passage therethrough of ozone and fluid being cleaned, the second isolation chambers having fins defining channels located along the axis of the container; and a dynamic mixing zone with mechanisms between the input and output zones for intermixing t

Abstract: In an apparatus for reducing the nitrogen oxide emission of an internal combustion engine wherein the nitrogen oxides are removed from the engine exhaust gas in an adsorber from which they are subsequently purged by hot gases, the hot gases with the nitrogen oxides purged from the adsorber are returned to the air intake of the internal combustion engine for reaction in the combustion process in the internal combustion engine in which the nitrogen oxide is converted to nitrogen and oxygen.

Abstract: A method and apparatus for producing an inert gas is described. Firstly, capture the exhaust from a gas fired internal combustion engine located on the site of an intended application. Secondly, pass the exhaust stream through at least one catalytic converter. Thirdly, cool the exhaust stream passing from the catalytic converter to a temperature that will not harm a gas compressor. Fourthly, pass the exhaust stream into the gas compressor and apply the compressed exhaust stream exiting the compressor directly to the intended application.

Abstract: An apparatus for supplying the secondary air to a catalyst in an exhaust gas passage is disclosed. An electric heater is fixed to the catalyst to which the secondary air is supplied by an electric air pump. The heater and the air pump are connected with a battery through relay contacts, respectively. During the cold operation of the engine, an electric control unit switches on/off the relay contacts, so as to actuate the air pump prior to the heater and stop the air pump after the heater. The secondary air is supplied to the catalyst when the temperature of catalyst is raised up to the activating point.

Abstract: An engine air/fuel control system (8) and method for controlling an engine (28) coupled to a catalytic converter (50) and for providing a measurement of engine emissions (202-296). Nitrogen oxides concentration, hydrocarbon concentration, and carbon monoxide concentration of exhaust gases downstream of the converter are measured (46, 54, and 52). Each concentration measurement is averaged for the speed load cell in which such measurement occurred (244-256). Each concentration average measurement is converted to a measurement of mass emissions emitted during a test cycle (268-284). Fuel delivered to the engine is corrected by a feedback variable (104-134, 158-178) derived from both an exhaust gas oxygen sensor (44) positioned upstream of the converter and the three sensors positioned downstream of the converter (46, 52, 54). A measurement of emissions in response to the averaged mass measurements of emission concentration downstream of the converter is also provided (278-296).

Abstract: An improved exhaust cutout device is provided for an engine having a collector pipe from a header and an exhaust pipe to a muffler. The device consists of a mechanism for diverting exhaust gases. Elements are for fluidly coupling the diverting mechanism between the collector pipe and the exhaust pipe. A structure is for operating the diverting mechanism. In a first operable position, the exhaust gases can pass between the collector pipe and the exhaust pipe to pass through the muffler for a quiet exhaust for city and restricted areas. In a second operable position, the exhaust gases can exit directly into the atmosphere for open road, racing purposes and country driving when more speed, more power and gas economy is required.

Abstract: In an exhaust gas system for an internal combustion engine for a vehicle which includes an exhaust gas conduit with an exhaust gas cleaner and a silencer, the structure-borne noise emission is reduced by coating surface areas of the exhaust system with a silencing layer consisting of metal powder which is applied by plasma spraying or sintering.

Abstract: A NO.sub.x absorbent (17) is disposed in an exhaust passage of an internal combustion engine. This NO.sub.x absorbent (17) absorbs the NO.sub.x when the air-fuel ratio of the exhaust gas flowing into the NO.sub.x absorbent (17) is lean and releases the absorbed NO.sub.x when the air-fuel ratio of the exhaust gas flowing into the NO.sub.x absorbent (17) becomes rich. When making the air-fuel ratio of the exhaust gas flowing into the NO.sub.x absorbent (17) rich to release the NO.sub.x from the NO.sub.x absorbent (17), the degree of richness is made larger and the time the ratio is made rich is made shorter the higher the temperature of the NO.sub.x absorbent (17).

Abstract: A catalyst deterioration-determining device for an internal combustion engine having first and second exhaust sensors positioned in an exhaust path of the internal combustion engine upstream downstream, respectively, of a catalyzer located in the exhaust path. The internal combustion engine further including a control station for effecting feedback control to match an air-fuel ratio with a desired value in accordance with first and second detection signals from the first and second exhaust sensors, respectively. The catalyst deterioration-determining device including a determining section provided in the control station which obtains a deterioration-determined value from calculations based on a rich determination delay time, a lean determination delay time, a lean response delay time and a rich response delay time when a deteriorated state of the catalyzer is determined.

Abstract: An exhaust gas purification device of the present invention includes a three-way reducing and oxidizing catalyst disposed on an exhaust passage of an engine, and an NO.sub.x absorbent which absorbs NO.sub.x in the exhaust gas when the air-fuel ratio of the exhaust gas is lean and releases absorbed NO.sub.x when the air-fuel ratio of the exhaust gas is rich; the engine in the present invention is controlled in most of its operating region in such a manner that the operating air-fuel ratio of the engine oscillates between a rich air-fuel ratio and a lean air-fuel ratio about a center value of a stoichiometric air-fuel ratio; when the operating air-fuel ratio of the engine becomes lean, the ability of the three-way catalyst for reducing NO.sub.x in the exhaust gas becomes low, and a part of NO.sub.x in the exhaust gas passes through the three-way catalyst, and, since the air-fuel ratio of the exhaust gas is lean, this NO.sub.x is absorbed in the NO.sub.

Abstract: A catalyst warming up device of an internal combustion engine includes an electrically heated type catalyst disposed in an exhaust gas passage of the engine and a unit for supplying secondary air into the exhaust gas passage at an upstream of the catalyst. The secondary air supply and the catalyst energization are controlled in such a manner that, during an engine warming up condition, in which an air-fuel ratio of a mixture introduced into engine cylinders is controlled to be rich, if the air-fuel ratio of the exhaust gas is detected as lean or the same as a theoretical air-fuel ratio due to the secondary air, the secondary air is supplied to the exhaust gas passage after the catalyst is energized, and if the air-fuel ratio of the exhaust gas cannot be controlled to lean or the same as a theoretical air-fuel ratio, an operation of the catalyst energization is stopped.

Abstract: The invention is directed to a method and an arrangement for controlling the supply of secondary air to the exhaust gas of an internal combustion engine. A method for diagnosing this arrangement is also provided. The arrangement includes an electrically operated secondary air pump which can be operated in at least two stages in dependence upon operating parameters of the engine. In this way, the supply of secondary air can be finely adapted to the actual value of the exhaust gas quantity supplied by the engine. This fine adaptation is determined by the number of stages. Resistors are switched into the current supply of the secondary air pump for the drive which has at least two stages.

Abstract: A calorimetric sensor comprising closely spaced, similarly constructed catalyzed (oxidation catalyst) and uncatalyzed members can be placed in the exhaust gas stream of an automotive engine downstream of a catalytic converter to aid assessment of the efficacy of the converter, especially when the exhaust is hot and at an appreciable steady flow rate and the engine is operating at the stoichiometric air-to-fuel ratio or lean of such ratio.

Abstract: An EGR system comprising a take-out port of the exhaust gas located downstream of the catalytic converter and upstream of the muffler, and an EGR control valve provided at the confluent portion of the intake air and the recirculated exhaust gas. The EGR control valve controls the amount of the recirculated exhaust gas by means of a slide valve therein which varies the opening area according to the electric current from the engine electronic control unit.