Abstract: A system for maintaining engine air/fuel operation within the efficiency window of a catalytic converter. Fuel delivered to the engine is adjusted in response to a step change in an output of an exhaust gas oxygen sensor positioned upstream of the converter. The step change is shifted in response to an error signal derived from a downstream emissions sensor.

Abstract: A control system for maintaining engine air/fuel operation within the efficiency window of a catalytic converter. An exhaust gas oxygen sensor having a step change between first and second output states and positioned downstream of the converter. A step change in the downstream sensor output is initialized to an initial air/fuel ratio by pumping current through one of the sensing electrodes of the downstream sensor. An emission control signal is derived from the initialized downstream sensor output to bias an air/fuel feedback loop.

Abstract: A control apparatus and method for maintaining equal air flow among cylinders and independently controlling the air/fuel ratio of each individual cylinder, in an internal combustion engine having variable valve control. An air fuel controller generates valve control signals for each individual cylinder by sampling the exhaust gas oxygen sensor, and correlating the samples with corresponding combustion events. The valve lift for each variable lift valve is corrected to operate each cylinder at the desired air flow and air/fuel ratio. The variable valve lift can be accomplished in a camshaft type system incorporating a lost motion mechanism or similar device, or a system incorporating direct electrohydraulic or electromechanical valve actuation without a camshaft. The system and method can provide further flexibility in cylinder to cylinder air/fuel ratio control by combining it with a variable pulse width electronic fuel injector capability.

Abstract: An air/fuel control system for internal combustion engines having three-way (NOx, CO, and HC) catalytic converters. A feedback variable is generated by subtracting the normalized output of a nitrogen oxide sensor from the normalized output of a combined HC/CO sensor. The zero crossing point of the feedback variable identifies the operating point for optimal conversion efficiency of the catalytic converter and is used to trim liquid fuel delivery for maintaining optimal conversion efficiency.

Abstract: A method of detecting catalyst malfunction in a vehicle uses an exhaust gas oxygen sensor downstream of the catalyst. A feedback loop controls the air-fuel ratio as a function of the output signal from the exhaust gas oxygen sensor. The feedback gain is increased from low gain to high gain and then operational parameters are examined. In a first version the amplitude of the exhaust gas oxygen sensor is used as an indication. In a second version, the amplitude of the exhaust gas oxygen sensor reaches a predetermined limit and then the feedback gain is examined. In a third version, limit-cycle operation is reached and the frequency of the limit-cycle is examined with respect to a predetermined frequency.

Abstract: An exhaust gas sensor system for use with an internal combustion engine having an exhaust conduit and a catalytic converter. The system includes an exhaust gas oxygen sensor, temperature sensor, and signal conditioner. The exhaust gas oxygen sensor is positioned on the conduit, downstream of the catalytic converter, and provides an oxygen level signal. The temperature sensor is also downstream of the catalytic converter, sensing the temperature of the oxygen sensor. A signal conditioner receives outputs from both the exhaust gas oxygen sensor and the temperature sensor. The oxygen level signal from the oxygen sensor is adjusted, according to the temperature sensed by the temperature sensor, to provide a more accurate oxygen level signal to other components of the engine such as, for example, an air-fuel controller.

Abstract: Disclosed is a method and apparatus for determining the hydrocarbon conversion efficiency of a catalytic converter used in conjunction with an internal combustion (IC) engine to reduce the pollutants contained in the IC exhaust gas comprising the steps of: (a) determining the hydrocarbon content of the IC exhaust gas prior to its entry into the catalytic converter by sampling the exhaust and passing the sample to a catalytic differential calorimetric sensor; (b) contacting the catalyst in the converter with the IC exhaust; (c) determining the hydrocarbon content of the exhaust leaving the catalytic converter by sampling the exhaust and passing the sample to the catalytic differential calorimetric sensor; and (d) comparing the hydrocarbon contents of the exhaust samples from steps (a) and (c) and thereby determining the hydrocarbon conversion efficiency of the catalyst in the converter.

Abstract: A control system for engines equipped with both a fuel vapor recovery system and an air/fuel ratio feedback control system. The air/fuel ratio feedback control system regulates delivery of fuel in response to an exhaust gas oxygen sensor such that the mixture of air, fuel, and recovered fuel vapor approximates a desired air/fuel ratio. The fuel vapor recovery system includes two parallel solenoid valves which are phased controlled by a phase controller responsive to a measurement of inducted airflow such that total purge flow through both valves is proportional to inducted airflow.

Abstract: A sulfur recovery process including a Claus reaction wherein sulfur-containing compounds are converted to elemental sulfur in the presence of a stoichiometric excess of hydrogen sulfide. The sulfurous compounds in the tail gas of the Claus reaction are separated for recycle using crystallization. Liquid carbon dioxide absorption is used to separate substantially all sulfur-containing compounds from a residual tail gas suitable for venting to the atmosphere.

Abstract: An air/fuel ratio control system and method for correcting the air/fuel ratio for each of N cylinders in an internal combustion engine having electronically actuated fuel injectors coupled to each cylinder. A first air/fuel controller provides a desired fuel command for maintaining an average air/fuel ratio among the cylinders in response to an exhaust gas oxygen sensor and a measurement of inducted air flow. A second air/fuel controller generates N trim signals by sampling the exhaust gas oxygen sensor once each combustion period, synchronizing the samples to generate N nonperiodic samples, correlating the samples with the corresponding combustion event and integrating. The fuel command to each fuel injector is then trimmed for operating each cylinder at a desired air/fuel ratio.

Abstract: A fuel delivery control system for a multiport fuel injected internal combustion engine. A fuel vapor recovery system periodically purges fuel vapors from the fuel system into the intake manifold under control of a purge controller. The intake manifold has a separate runner coupled to each combustion chamber with a separate primary fuel injector coupled thereto. A secondary fuel injector of smaller size is coupled to the intake manifold upstream of the primary fuel injectors. Primary and secondary fuel injectors are controlled, respectively, by a primary fuel injection controller and a secondary fuel injection controller. Both primary and secondary fuel injection controllers are responsive to a desired fuel charge related to a desired air/fuel ratio of a mixture of air, injected fuel, and fuel vapors injected into the engine. The desired fuel charge is generated in response to a measurement of inducted airflow and a feedback indication of actual air/fuel ratio from an exhaust gas oxygen sensor.

Abstract: A connection system for electrical conductors is disclosed. The system involves an outer sheath manufactured from a material transparent to ultraviolet light. A tubular, deformable crimp ferrule is inserted within the sheath. Thereafter, a portion of ultraviolet-curable adhesive is placed within the ends of the sheath, which are covered with cap members to retain the adhesive inside. To connect the conductors (e.g. insulated wires or cables) the ends thereof are pushed through the cap members, through the ultraviolet-curable adhesive, and into the crimp ferrule. The crimp ferrule is then deformed to securely engage the ends of the conductors. Ultraviolet light is subsequently applied which passes through the sheath, causing the adhesive to solidify. The foregoing process produces a strong and secure bond between the conductors, and is readily adaptable to large-scale, mass production manufacturing conditions using a minimal amount of time and labor.

Abstract: An apparatus and a method for controlling hydrocarbon emission from an internal combustion engine having an air/fuel intake coupled to a fuel vapor recovery system. Fuel vapors are periodically purged from the fuel vapor recovery system into the air/fuel intake. The mixture of air fuel vapor and fuel inducted into the air/fuel intake is regulated by a feedback loop responsive to an exhaust gas oxygen sensor to maintain a desired air/fuel ratio. An indication of the fuel vapor concentration in the fuel vapor recovery system is provided to control various engine parameters and thereby reduce hydrocarbon emissions during the response time of the feedback loop. In one aspect of the invention, the flow rate of the purged fuel vapors is controlled to be in inverse relation to the concentration of purged fuel vapors during the response time of the feedback loop.

Abstract: An apparatus and a method for controlling hydrocarbon emission from an internal combustion engine having an air/fuel intake coupled to a fuel vapor recovery system. Fuel vapors are periodically purged from the fuel vapor recovery system into the air/fuel intake. The mixture of air/fuel vapor and fuel is regulated by a feedback loop response to an exhaust gas oxygen sensor to maintain a desired air/fuel ratio. At the beginning of each purge cycle, engine spark timing is temporarily retarded to reduce hydrocarbon emissions during the response time of the feedback loop.

Abstract: An improved crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid phase of the materials. The solid phase is more dense than the liquid phase, and it is separated therefrom by relative movement with the formation of a packed bed of solid phase. The packed bed is continuously formed adjacent its lower end and passed from the liquid phase into a countercurrent flow of backwash liquid. The packed bed extends through the level of the backwash liquid to provide a drained bed of solid phase adjacent its upper end which is melted by a condensing vapor.

Abstract: A wave compression supercharger comprises a rotor mounted for rotation about its longitudinal axis having axially disposed cells formed about its periphery, a shroud surrounding the rotor, a first port plate located between the rotor and an air duct that delivers ambient air to the supercharger rotor and delivers pressurized air to the air intake side of the engine. A second port plate located between the rotor and an exhaust duct carries low pressure gas from the rotor and high pressure engine exhaust gas to the rotor. A hydraulic cylinder has a piston mounted for sliding motion in the cylinder. A mechanical governor driven by the rotor of the supercharger controls a source of pressurized hydraulic fluid that is opened to the cylinder according to variations in the speed of the rotor. The piston is connected to a port plate and delivers a tangential force to the plate causing it to rotate with respect to the longitudinal axis of the rotor.

Abstract: A ceramic regenerator core of cylindrical configuration adapted to be mounted in a gas turbine engine for rotation about its geometric axis comprising a honeycomb matrix that accommodates the flow of hot exhaust gases in an axial direction through one segment of the matrix and the flow of cool intake air through another segment of the matrix as the core is rotated, the matrix passages being formed by contiguous parallelogram shape passages, the principal diagonal for each passage generally parallel to the direction of maximum stress in the core whereby a maximum degree of thermal stress resistance is achieved thus reducing the possibility of fracture of the matrix material.