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Showing papers on "Secondary air injection published in 1978"


Patent
13 Nov 1978
TL;DR: In this paper, a stoichiometric fuel air mixture is introduced and the amount of exhaust gas recirculation is such that a minimum amount of air is inducted into the combustion chamber through the other intake passage when exhaust gas re-circulation is being accomplished.
Abstract: A number of embodiments of inductions and fuel injection systems for internal combustion engines that improve exhaust emission control and fuel economy without adversely effecting the running of the engine under any running condition. This is accomplished by injecting fuel into one of at least two intake passages and providing exhaust gas recirculation into another of the intake passages. A stoichiometric fuel air mixture is introduced and the amount of exhaust gas recirculation is such that a minimum amount of air is inducted into the combustion chamber through the other intake passage when exhaust gas recirculation is being accomplished. Both two and three intake valve systems are disclosed and these use either control valves for controlling the flow through the other intake passages or operate without control valve. In addition an arrangement is provided wherein the spray from a single fuel injector may be deflected into several of the intake passages under certain running conditions so as to provide a more uniform fuel introduction without necessitating multiple fuel injectors.

81 citations


Patent
22 May 1978
TL;DR: In this article, an improved turbocharged engine system consisting of a piston engine with an inlet manifold, an exhaust manifold, a turbine driven by exhaust gases for transporting a portion of the exhaust gas energy to drive a compressor between a gas intake and the manifold is described.
Abstract: An improved turbocharged engine system comprising a piston engine with an inlet manifold, an exhaust manifold, a turbine driven by exhaust gases for transporting a portion of the exhaust gas energy to drive a compressor between a gas intake and the inlet manifold. There is used as the exhaust manifold a first exhaust manifold receiving exhaust gases only from a first set of pistons and a second exhaust manifold receiving exhaust gases only from a second set of pistons. The turbine comprises a first turbine driven by first exhaust manifold exhaust gases. The compressor comprises a first compressor driven by the first turbine. A portion of the exhaust gases from the second exhaust manifold are recycled to the inlet manifold.

63 citations


Patent
17 May 1978
TL;DR: In this paper, a method and apparatus for measuring the O2 content in an exhaust gas of an internal combustion engine by exposing two resistors to the exhaust gas was presented, where the resistance of both resistors varies as a function of the temperature of the exhaust to which it is exposed.
Abstract: METHOD AND APPARATUS FOR MEASURING ABSTRACT OF THE INVENTION A method and apparatus for measuring the O2 content in an exhaust gas of an internal combustion engine by exposing two resistors to the exhaust gas of an internal combustion engine. The resistance of both resistors varies as a functional of the temperature of the exhaust gas to which it is exposed. However, the resistance of one of the resistors also varies as a function of the oxygen content of the exhaust gas. Therefore, an electrical signal can be obtained which is a function of the O2 content of the exhaust gas, with the temperature effect of the exhaust gas on the resistor being minimized and/or eliminated.

35 citations


Patent
15 Nov 1978
TL;DR: In this paper, the secondary combustion chamber of an aircraft engine is blown over wing and fuselage surfaces to mix with air and fuel and recombusted, and the exhaust is then mixed with fuel and air.
Abstract: Aircraft engine exhaust is mixed with air and fuel and recombusted. Air is drawn into the secondary combustion chamber from suction surfaces on wings. Exhaust of the secondary combustion chamber is blown over wing and fuselage surfaces.

31 citations


Patent
13 Jan 1978
TL;DR: In this article, a recirculating and recombustion type of exhaust gas purification system for a compression ignition engine includes an expansion manifold communicating with auxiliary combustion chambers of each cylinder through separate passages.
Abstract: A recirculating and recombustion type of exhaust gas purification system for a compression ignition engine includes an expansion manifold communicating with auxiliary combustion chambers of each cylinder through separate passages. Cam operated valves are located in each of the separate passages. The exhaust gas in an auxiliary combustion chamber is expanded into the manifold through one of the cam operated valves and is then drawn into the auxiliary combustion chamber of another cylinder whose piston is near the bottom of its intake or suction stroke via another open cam operated valve. The thus recirculated or transferred exhaust gas is cooled by its expansion into the manifold, water jacketing within the cylinder head and air surrounding the exposed periphery. Further, in high load operation of the engine, a single butterfly valve disposed midway of the expansion manifold can control the amount of the exhaust gas circulation to improve the engine operation.

31 citations


Patent
11 Jan 1978
TL;DR: In this article, a water vapor injection system for introducing artificially high humidity air into the carburetor of an internal combustion engine is described, which significantly increases the efficiency of the combustion process within the internal combustion process.
Abstract: The present invention relates to a water vapor injection system for introducing artificially high humidity air into the carburetor of an internal combustion engine Once delivered to the carburetor, the high humidity or moisture-laden air mixes with the air-fuel mixture normally passing from the carburetor into the combustion chambers to increase the combustion efficiency of the internal combustion engine A forced air system is generated by an air injection pump, and this forced air is heated to alter its vaporization characteristics prior to being circulated through a water filled container As the heated air is exposed to the water within the container, the air increases in moisture content as the heat associated with the air tends to vaporize water about the interface between respective bubbles and the surrounding water Because of the continuous force of the pump, the high moisture air realized from passing the air through the water filled container is then forced from the container into the immediate area of the top of the carburetor There the moisture-laden air generated by the water vapor injection system is mixed with the normally injected air supply and, accordingly, the water content of the final air-fuel mixture is increased which, expressed generally, significantly increases the efficiency of the combustion process within the internal combustion engine

31 citations


Patent
03 Jan 1978
TL;DR: In this paper, a waste heat recovery system and method for recovering heat from exhaust gases flowing through an exhaust stack or flue from a source of heat is presented, which includes a heat exchanger located within a bypass assembly.
Abstract: A waste heat recovery system and method for recovering heat from exhaust gases flowing through an exhaust stack or flue from a source of heat. The recovery system includes a heat exchanger located within a bypass assembly that includes a pair of conduits connected to the exhaust stack, and a blower for producing a flow of exhaust gases from the exhaust stack through one of the conduits and the heat exchanger and then back to the exhaust stack through the other of the conduits. The method of the present invention includes the moving of at least a portion of the exhaust gases in the exhaust stack through the bypass assembly and returning such portion back to the exhaust stack.

27 citations


Patent
Mase Yoshio1, Natsuume Shinichi1
08 Feb 1978
TL;DR: In this article, the exhaust communicating pipe interconnecting two adjacent exhaust pipes is divided into two sections, which are fixed at one end to the respective exhaust pipes and held at the other end in aligned abutting relation by a radially expansible tubular joint member.
Abstract: A catalytic exhaust cleaning device for a high-power multi-cylinder engine of the type including independent carburetors and exhaust pipes for the respective cylinders. The exhaust pipes are interconnected for fluid communication therebetween at locations upstream of the respective catalytic converters arranged therein so that the latter are evenly fed with exhaust gases of substantially the same composition and volume and with substantially equal amounts of secondary air and operate effectively with substantially the same high efficiency. The exhaust communicating pipe interconnecting two adjacent exhaust pipes is divided into two sections, which are fixed at one end to the respective exhaust pipes and held at the other end in aligned abutting relation by a radially expansible tubular joint member, which is fixed to one of the two pipe sections and clamped against the other section. This structure not only facilitates assembly of the communicating and exhaust pipes but effectively prevents any thermal deformation of the communicating pipe.

25 citations


Patent
24 Mar 1978
TL;DR: The valve chamber has relatively narrow entry and exit orifices in order to increase the velocity of the pulsations generated therein while at the same time reducing the amount of supplemental air flow through the device.
Abstract: Valve device includes a valve chamber containing three spherical members of different hardnesses in stacked relation therein, which produce a limited pulsating air flow that is metered in precise amounts at any given time into the fuel/air path of a gasoline powered internal combustion engine to maintain a narrow band air/fuel ratio over substantially all operating modes. The valve chamber has relatively narrow entry and exit orifices in order to increase the velocity of the pulsations generated therein while at the same time reducing the amount of supplemental air flow through the device. The valve seat also has a conical shape to establish line contact with one of the spherical members to assist in obtaining maximum resonation during operation and provide a more positive seal when the engine is not running. The pulsating air from the valve device is preferably introduced into the carburetor beneath the throttle plate in close proximity below the gas idle jets, providing pressure waves therein that produce turbulence substantially throughout the manifold to assist in remixing and atomizing of the fuel and air, whereby substantially equal air/fuel ratio is supplied to every cylinder for better fuel combustion, with consequent increased power, reduced exhaust pollution, and improved fuel economy.

25 citations


Patent
18 Jan 1978
TL;DR: In this article, a method and exhaust manifold for damping the pressure oscillations in an exhaust manifold of an internal combustion engine, consisting in throttling the gas flow in the vicinity of the cylinder outlet and then accelerating the gases flowing in the manifold by providing a uniform flow section in a manifold substantially smaller than the cylinder bore, is presented.
Abstract: Method and exhaust manifold for damping the pressure oscillations in an exhaust manifold of an internal combustion engine, consisting in throttling the gas flow in the vicinity of the cylinder outlet and then in accelerating the gases flowing in the manifold by providing a uniform flow section in the manifold substantially smaller than that of the cylinder bore.

23 citations


Patent
Kyo Hattori1
04 Apr 1978
TL;DR: In this article, a secondary air supply system for the exhaust system of an internal combustion engine having a catalytic converter with a three-way catalyst, having an air control valve which selectively supplies a part of compressed air to the exhaust, while relieving the rest of the air in the atmosphere, is described.
Abstract: A secondary air supply system for the exhaust system of an internal combustion engine having a catalytic converter with a three-way catalyst, having an air control valve which selectively supplies a part of compressed air to the exhaust system while relieving the rest of the air to the atmosphere, wherein the air control valve has a valve element balanced by oppositely acting springs to a neutral position where it supplies a predetermined amount of secondary air necessary to provide stoichiometric exhaust gases at a standard flow of exhaust gases and is shifted to opposite sides of the neutral position in accordance with oscillation of feedback control of the air/fuel ratio of exhaust gases.

Patent
17 Jul 1978
TL;DR: In this paper, a cylindrical chamber attached in line with the exhaust of an automotive vehicle, which in conjunction with the velocity and heat of emitted exhaust gases further heats and burns emitted gases exiting the tail pipe into relatively harmless non-polluted vapors.
Abstract: An anti-pollution device includes a cylindrical chamber attached in line with the exhaust of an automotive vehicle, which in conjunction with the velocity and heat of emitted exhaust gases further heats and burns emitted gases exiting the tail pipe into relatively harmless non-polluted vapors. The chamber is affixed in line with the exhaust tail pipe of an automotive vehicle near the exhaust manifold and consists of a cylindrical outer and inner shell with insulation therebetween with a three stage system constructed internally along the length of the chamber for progressively heating and burning of exhausted gases and finally cooling thereof. In one form the first stage consists of a spiraled ceramic cone for accelerating and concentrating the exhaust fumes into the second stage consisting of a series of ceramic rings for burning of exhaust gases, the burned exhaust fumes then passing therefrom into the third stage consisting of a porcelain lined cooling pipe for cooling of exhaust gases prior to their emission out of an automotive vehicle. In another form there is a source of energy for heating the gases in a Venturi tube combustion section by igniting the gases, and there is further provided an arrangement for introducing controlled amounts of air in the combustion section to enhance combustion of the gases.

Patent
18 Jan 1978
TL;DR: In this paper, a diesel engine with a throttle valve disposed in an intake passage, which gradually opens in accordance with an increase in the level of the load of the engine, is described.
Abstract: The present invention is directed to a to a diesel engine comprising a throttle valve disposed in an intake passage, which gradually opens in accordance with an increase in the level of the load of the engine. A recirculated exhaust gas conduit is also provided for recirculating a partial amount of the exhaust gas into the intake passage located at the downstream side side of the throttle valve so that the exhaust gas recirculation ratio could be reduced in accordance with an increase in the level of the engine load. In addition a solenoid valve is disposed in the recirculated exhaust gas conduit for stopping the recirculating of the exhaust gas when the engine is being operated under a heavy load.

Journal ArticleDOI
A. A. Quader1
TL;DR: Oxygen was added to the intake air of a spark ignition engine to determine its effects on exhaust emissions and engine performance as mentioned in this paper, which can be largely attributed to high flame temperatures and/or flame speeds with Os enriched air.
Abstract: Oxygen was added to the intake air of a spark ignition engine to determine its effects on exhaust emissions and engine performance. Increasing the content of O2 in the intake air of the engine from 21 to 32 percent by volume, increased exhaust nitric oxide emissions, decreased exhaust hydrocarbon emissions, decreased thermal efficiency and permitted leaner engine operation. These effects can be largely attributed to high flame temperatures and/or flame speeds with Os enriched air.

Patent
15 Mar 1978
TL;DR: In this paper, a feedback control system for controlling the flow rate of a gas which is either drawn from or introduced into an exhaust passage of an internal combustion engine for the purpose of lessening pollutants in the exhaust gas.
Abstract: A feedback control system for controlling the flow rate of a gas which is either drawn from or introduced into an exhaust passage of an internal combustion engine for the purpose of lessening pollutants in the exhaust gas. The control system is embodied either as an exhaust gas recirculation control system or a secondary air injection control system and in either case comprises an electrically operated flow control valve, a control circuit to provide a control signal to the control valve based on input signals representing the engine operating condition so as to establish an optimum flow rate, and an electrostatic type flow rate detector which has the ability of forming ions in the gas to provide a feedback signal on an electrical principle.

Proceedings ArticleDOI
01 Feb 1978
TL;DR: A combination of closed loop air/fuel ratio control and three-way catalytic converter was introduced on some 1978 GM cars sold in California as discussed by the authors, and two engine families were involved in the production of the basic system: one with vacuum actuated metering controls and the other with electromechanically driven metering control.
Abstract: A combination of closed loop air/fuel ratio control and three-way catalyst has been introduced on some 1978 GM cars sold in California. The three-way catalytic converter simultaneously acts on hydrocarbons, carbon monoxide, and oxides of nitrogen exhaust pollutants. An exhaust gas sensor gives an indication of rich or lean exhaust, and an electronic control unit processes this information and converts it into a command signal to the carburetor. The closed-loop carburetor controls the air/fuel ratio fed to the engine to the proper levels required for good operation of the catalytic converter. Two engine families are involved in the production of the basic system: one with vacuum actuated metering controls and the other with electromechanically driven metering controls. The 1978 California emission standards are met, and driveability is good while fuel economy loss is minimized.

Patent
06 Jul 1978
TL;DR: In this paper, two catalysts at a prescribed spacing in an exhaust gas passage and placing the first catalyst at a high-temperature part near a cylinder were used to purify exhaust gas in two stages.
Abstract: PURPOSE:To very surely purify exhaust gas in two stages, by providing two catalysts at a prescribed spacing in an exhaust gas passage and placing the first catalyst at a high-temperature part near a cylinder. CONSTITUTION:The exhaust gas is discharged from the cylinder 1b through an exhaust port 1a so that the exhaust gas comes into contact with the first catalyst 9 for oxidation. The carbon monoxide and hydrocarbon in the exhaust gas are thus decreased. The exhaust gas is then passed through an exhaust cover 2 and holes 1c, 3a so that the gas comes into contact with the second catalyst 10 for oxidation of not yet oxidized carbon monoxide and hydrocarbon. The exhaust gas is then released through an exhaust pipe 4. Because the catalysts are provided in two stages, the exhaust gas is purified well. Since the first catalyst is located near the cylinder 1b, the oxidation is caused at the place where the temperature of the exhaust gas is still high. The efficiency of the purification is thus raised further.

Patent
01 Aug 1978
TL;DR: In this paper, the steel-refining process is carried out in a closed converter maintained at a pressure of from 1 to several atmospheres above ambient pressure, and the converter exhaust gases at such elevated pressure is subjected to washing, preferably in the exhaust-gas stack or duct and the washed converter exhaust gas from several refining processes is stored and supplied to a gas consumer, e.g. an electrical generating plant, at a rate which is independent of the blowing period.
Abstract: Converter exhaust gases in a steel-refining plant are used for the recovery of energy, e.g. for the production of electrical energy. The steel-refining process is carried out in a closed converter maintained at a pressure of from 1 to several atmospheres gauge above ambient pressure. The converter exhaust gases at such elevated pressure is subjected to washing, preferably in the exhaust-gas stack or duct and the washed converter exhaust gases from several refining processes is stored and supplied to a gas consumer, e.g. an electrical generating plant, at a rate which is independent of the blowing period.

Patent
21 Jun 1978
TL;DR: In this article, an exhaust silencer for internal combustion engines, particularly for manually operated appliances, is described, in which a reduction of the contact and exhaust gas temperatures in order to prevent fire risks on contact with easily flammable objects, particularly forest fires, during the putting into operation of the manually operated appliance and with the supply of a large quantity of fresh air compared with the quantity of exhaust gas to bring about a maximum cooling of the hottest gases and/or the outer walls, is achieved.
Abstract: The invention relates to an exhaust silencer for internal combustion engines, particularly for manually operated appliances, in which a reduction of the contact and exhaust gas temperatures in order to prevent fire risks on contact with easily flammable objects, particularly forest fires, during the putting into operation of the manually operated appliance and with the supply of a large quantity of fresh air compared with the quantity of exhaust gas in order to bring about a maximum cooling of the hottest gases and/or the outer walls, is achieved in that the wall of the exhaust silencer shell portion which bounds the cooling pipe on one side, following the final outlet hood facing the pipe output port for deflecting the exhaust gas has a negative angular variation with an angle of approximately 2° to 8° for forming a pure or fluidic logic element.

Patent
28 Jun 1978
TL;DR: In this article, a valve control arrangement for controlling the flow of exhaust gas from an exhaust manifold to an air inlet of an internal combustion engine which is supplied with fuel by a fuel pump is described.
Abstract: The invention relates to a valve control arrangement for controlling the flow of exhaust gas from an exhaust manifold to an air inlet of an internal combustion engine which is supplied with fuel by a fuel pump. The quantity control member of the pump is connected through linkage to a valve through which exhaust gas can flow into a conduit connected to the air inlet manifold. In this manner the quantity of exhaust gas recirculated depends upon the setting the control member of the pump. A further valve is positioned upstream so far as exhaust gas is concerned, of the valve and the further valve is adjusted so that it maintains the pressure drop across the first mentioned valve substantially constant. This is achieved in the example, by means of a diaphragm opposite sides of which are responsive to the pressure on opposite sides of the first mentioned valve.

Patent
Koichiro Yamada1
14 Nov 1978
TL;DR: In an exhaust bypassing system for a turbocharger for use with an internal combustion engine such as automobile engine, an opening is provided in the wall of an exhaust passage so as to introduce the exhaust pressure of the engine into the interior of a diaphragm of a valve assembly which adjusts the quantity of exhaust gas to be bypassed as discussed by the authors.
Abstract: In an exhaust bypassing system for a turbocharger for use with an internal combustion engine such as automobile engine, an opening is provided in the wall of an exhaust passage so as to introduce the exhaust pressure of the engine into the interior of a diaphragm of a valve assembly which adjusts the quantity of exhaust gas to be bypassed and in which a rod having a valve body at its fore end is attached to the diaphragm.

Patent
Baresel Detlef Dr1
28 Feb 1978
TL;DR: In this paper, the exhaust gases are conducted past a first sensor, which provides a clearly defined voltage jump upon change of exhaust gases between reducing and oxidizing state; and, additionally, to a second exhaust gas sensor and preferably to a third sensor, the second and third sensors being, respectively, responsive to the oxygen level in the exhaust gas and to the CO (or hydrocarbon) level in exhaust gases, respectively; modifying the relative proportion of fuel and air of the mixture being fed to the engine.
Abstract: To detect substantial deviation of operation of the engine with fuel-air mixtures from stoichiometric relationships, particularly extended operation under very lean or enriched supply mixtures, the exhaust gases are conducted past a first sensor which provides a clearly defined voltage jump upon change of the exhaust gases between reducing and oxidizing state; and, additionally, to a second exhaust gas sensor and preferably to a third sensor, the second and third sensors being, respectively, responsive to the oxygen level in the exhaust gases and to the CO (or hydrocarbon) level in the exhaust gases, respectively, and additionally modifying the relative proportion of fuel and air of the mixture being fed to the engine.

Patent
07 Sep 1978
TL;DR: In this paper, an exhaust gas control actuator consisting of a flow control valve and an electronic control circuit is presented, where the feed of secondary air fed to an exhaust piping is controlled by an oxygen concentration detector disposed in the stream of exhaust gas of an internal combustion engine.
Abstract: An exhaust gas control actuator wherein the feed of secondary air fed to an exhaust piping is controlled by an oxygen concentration detector disposed in the stream of exhaust gas of an internal combustion engine and an air-fuel ratio of the exhaust gas entering a catalyst disposed downstream of the exhaust piping is maintained within a given range. The actuator comprises a flow control valve and a flow control device for controlling the flow control valve. The flow control valve is provided with a flow-in port communicated with an air pump and the valve body, a flow-out port communicated with an exhaust manifold and a bypass port communicated with an air cleaner. Furthermore, the flow control device is actuated by an electronic control circuit and comprises an actuating chamber partitioned by a diaphragm for actuating the valve body and including a negative pressure introducing port communicated with an intake manifold and an atmosphere introducing port constantly communicated with atmosphere, and a nozzle flapper mechanism provided in the actuating chamber and varying resistances to flow through the negative pressure introducing port and the atmosphere introducing port in accordance with the actuating position of the valve body in such a manner that an output signal of the oxygen concentration detector in negatively fed back to the feed of secondary air.

Patent
24 May 1978
TL;DR: In this article, an internal combustion engine with an exhaust gas turbo-charger and with a control valve arranged in the exhaust gas manifold which responds to the charging pressure of the supercharging blower is described.
Abstract: An internal combustion engine with an exhaust gas turbo-charger and with a control valve arranged in the exhaust gas manifold which responds to the charging pressure of the supercharging blower; the control valve controls an exhaust gas by-pass line by-passing the exhaust gas turbine, while a catalyst is arranged in the exhaust gas manifold either upstream or downstream of the exhaust gas turbine.

Patent
05 Apr 1978
TL;DR: In this paper, the valve overlaps are increased in the normal driving operation range of the engine to prevent discharge at the terminal stage of exhaust valve opening exhaust gases containing a considerably large amount of hydrocarbons.
Abstract: An engine is provided with two spark plugs in each combustion chamber to ignite stoichiometric air-fuel mixture mixed with a large proportion of inert gases to lower NOx emission level. The engine is equipped with hydraulic valve lifters which are mechanically connected to intake and exhaust valves to control the valve overlap of the intake and exhaust valves. By the action of the valve lifters, the valve overlaps are increased in the normal driving operation range of the engine to prevent discharge at the terminal stage of exhaust valve opening exhaust gases containing a considerably large amount of hydrocarbons.

Proceedings ArticleDOI
01 Feb 1978
TL;DR: In this paper, a mathematical model is developed to represent an oxidizing catalytic converter in the exhaust system of a spark ignition engine in which the flow is non steady and a series of tests were carried out on a four cylinder two litre engine with a carbon monoxide and hydrocarbon oxidizing converter and secondary air injection.
Abstract: A mathematical model is developed to represent an oxidizing catalytic converter in the exhaust system of a spark ignition engine in which the flow is non steady A series of tests were carried out on a four cylinder two litre engine with a carbon monoxide and hydrocarbon oxidizing converter and secondary air injection Comparison of results between experiments and computer calculations shows excellent agreement when the converter is new, but that if the catalyst surface is poisoned or aged the hydrocarbon prediction deteriorates The carbon monoxide predictions, however, remain fairly good Prediction of the overall engine performance and emission levels is very good /SASI/

Patent
22 Dec 1978
TL;DR: In this paper, a drive assembly for motor vehicles consisting of an internal combustion engine and an exhaust gas turbine unit including a heat exchanger for transferring thermal energy from the exhaust gases to a working medium after the working medium has been compressed by the compressor.
Abstract: A drive assembly, especially for motor vehicles, of the type comprising an internal combustion engine and an exhaust gas turbine unit including an exhaust gas driven turbine is improved by virtue of structure for utilizing the heat energy of the exhaust gases of the internal combustion engine in addition to the kinetic energy. According to a preferred embodiment, the exhaust gas turbine unit comprises, in addition to the exhaust gas turbine, a compressor and a secondary turbine for deriving power from the heat energy of the exhaust gases. Still further, another feature includes the provision of a heat exchanger for transferring thermal energy from the exhaust gases to a working medium after the working medium has been compressed by the compressor, the heat exchanger being formed by hollow blades of the exhaust gas driven turbine.

Patent
27 Sep 1978
TL;DR: In this article, a pump and filter assembly suitable for circulating and filtering swimming-pool water is provided with a normally closed air-injection valve to aerate water flowing into a filtration element in the filter.
Abstract: A pump and filter assembly suitable for circulating and filtering swimming-pool water is provided with a normally closed air-injection valve to aerate water flowing into a filtration element in the filter. When the exterior surfaces of the element become covered with dirt or filter cake, the air-injection valve and an auxiliary filter outlet are opened. Air aspirated through the valve into the filter inlet water stream causes a churning cleaning action which dislodges the dirt, and the debris-laden water is discharged through the auxiliary outlet without passing through the element.

Patent
26 Dec 1978
TL;DR: In this article, a valve operated in response to the negative pressure in the intake pipe was used to protect the exhaust gases cleaning system and to clean the exhaust gas exhaust gases, and the effect was attained by using a valve operator to prevent the unburnt gas from flowing out into the exhaust passage.
Abstract: In an exhaust gas cleaning system wherein secondary air is supplied into the exhaust passage to re-burn the unburnt harmful component in the exhaust gases, a secondary air controlling apparatus for an internal combustion engine is provided. At deceleration of the vehicle, secondary air is interrupted from being fed into the exhaust passage, and is introduced into the intake passage to prevent after-burning in the exhaust cleaning system. When the ignition key is switched off, secondary air is fed into the intake passage to prevent the unburnt gas from flowing out into the exhaust passage. This effect is attained by using a valve operated in response to the negative pressure in the intake pipe to protect the exhaust gases cleaning system and to clean the exhaust gases.

Patent
Takeda Keisou1
09 Aug 1978
TL;DR: In this paper, a double feedback loop type of secondary air control system for an internal combustion engine is proposed, in which a valve provided in a secondary air feed passage for regulating a quantity of the secondary air fed into an exhaust passage of the engine is operated in response to a first error signal indicative of a deviation of the actual secondary air quantity from the desired secondary quantity and a second error signal indicating that a deviation from the actual air-fuel ratio from a desired air- fuel ratio, thereby effecting a precise control of the air fuel ratio.
Abstract: Disclosed is a double feedback loop type of secondary air control system for an internal combustion engine, in which a valve provided in a secondary air feed passage for regulating a quantity of the secondary air fed into an exhaust passage of the engine is operated in response to a first error signal indicative of a deviation of the actual secondary air quantity from the desired secondary air quantity and a second error signal indicative of a deviation of the actual air-fuel ratio from the desired air-fuel ratio, thereby effecting a precise control of the air-fuel ratio.