Abstract: Apparatus for controlling emissions from an internal combustion engine including an enclosed cylindrical housing and a converter assembly coaxially mounted in the housing for reducing noxious gases emitted from the engine. The converter assembly is characterized by a catalytic module transversely disposed within the housing at a predetermined location between an inlet and an outlet, thereof. The center of the catalytic module is formed by a cylindrical hub closed against flow of exhaust gases therethrough, surrounded by a catalytic cell of annular cross-section through which exhaust gases from the engine may flow, converting nitrogen oxides, carbon monoxide and unburned hydrocarbons to less noxious compounds before being discharged through the outlet. The hub is normally closed against flow of exhaust gases by a closure member. The closure member is openable in response to abnormal increases in pressure from the engine exhaust to prevent damage to the catalytic cell.

Abstract: The invention is directed at an exhaust system exhibiting an increased flow uniformity under diversion conditions comprising: (1) a honeycomb structure having an inlet and outlet end disposed in a housing located in an exhaust gas stream and downstream from an engine, and having a first substantially unobstructed flow region, and a second more obstructed flow region adjacent the first region, both providing a flow path for the exhaust gases in the exhaust gas stream; and, (2) a fluidics apparatus disposed in the exhaust stream comprising a diverter body located proximate to the first region, a diversion fluid source, a conduit for directing the diversion fluid toward the diverter body and an exhaust flow divergent device.

Abstract: The instant invention is directed at an in-line engine exhaust system comprised of the following: (1) a first close-coupled catalyzed structure located in the exhaust stream, the catalyzed structure having an inlet and an outlet end disposed in a housing, a lightoff temperature, and comprising a first substantially unobstructed flow region, and a second more obstructed flow region abutting the first region, the first region being disposed to provide a substantially unobstructed flow path for exhaust gases in the exhaust gas stream; and, (2) a flow diverter connected to a secondary air source and disposed in the housing for diverting the exhaust gases away from the first region. Furthermore, the exhaust system may be provided with a second catalyzed structure located in the exhaust gas stream downstream from the housing. Also disclosed herein is a method of treating a hydrocarbon-containing engine exhaust steam utilizing the aforementioned inventive exhaust system.

Abstract: A catalytic converter for a tailpipe which further reduces vehicle exhaust emissions from exhaust emission systems and that will meet the more stringent emission requirements of state and federal government regulations. The tailpipe catalytic converter includes a ceramic or steel housing which includes a matrix core of catalytic layered materials which react with the exhaust emission pollutants, such as NO.sub.x, NMHC, HC, and CO. These pollutants are further reduced and oxidized by the catalytic converter in the tailpipe by the typical catalytic materials of platinum, palladium, rhodium, or the like contained within the honeycombed or meshed layers of the matrix core. The catalytic converter is lodged within the interior of the tailpipe adjacent the open end or as an extension to the end of the tailpipe. The tailpipe catalytic converter is held in place by any suitable device, such as a clamp, mounting screws, or mounting brackets.

Abstract: The present invention provides an auxiliary catalytic converter having a back pressure relief device being disposed after the main catalytic converter or after the muffler system which further reduces vehicle exhaust emissions from exhaust emission systems and that will meet the more stringent emission requirements of state and federal government regulations. The auxiliary catalytic converter includes a ceramic or steel housing of relatively small size, having a diameter in the range of 1 inch to 8 inches and a length of 4 inches to 11 inches. The housing includes a matrix core of catalytic layered materials which react with the gaseous exhaust emission pollutants, such as NO.sub.x, NHMC, HC, and CO. These pollutants are further reduced and oxidized by the auxiliary catalytic converter using typical catalytic materials of platinum, palladium, rhodium, or the like contained within the honeycombed or meshed layers of the matrix core.

Abstract: A catalytic converter has an upstream catalyst-coated core and downstream catalyst-coated core housed in a same casing, the upstream core being provided with a heater. A bypass passage for bypassing the upstream core to the downstream core is formed between the casing and upstream core. By providing these two catalyst-coated cores and the bypass passage in the casing, the catalytic converter is rendered compact. Further, as the flowrate of exhaust gas through the upstream catalyst is reduced by the bypass passage, temperature rise of the upstream catalyst due to the heater is accelerated, and the emission amount of hydrocarbons and carbon oxides during engine warm-up is decreased.

Abstract: An air-fuel control system for an internal combustion engine is equipped with an exhaust system having a catalytic converter, a linear O.sub.2 sensor and a .lambda.O.sub.2 sensor for feedback controlling an air-fuel ratio on the basis of output representative of oxygen content from at least the linear O.sub.2 sensor. The system delivers a target air-fuel ratio of a fuel mixture. A determinant output, based on which the air-fuel ratio is feedback controlled, is shifted from output from the linear O.sub.2 sensor to output from the .lambda.O.sub.2 sensor before the linear O.sub.2 sensor is effectively active.

Abstract: An alternate valve assembly for a smoke re-combustion device of a engine includes a pair of alternate valves which are symmetrically installed at each inlet of filters connected with branches of an exhaust manifold.

Abstract: Disclosed herein is an outboard motor including a propulsion unit including an internal combustion engine having an exhaust port and an exhaust gas discharge system including a catalytic converter comprising a housing having an outer wall defining an axis, an inlet end with an inlet, and an outlet end with an outlet, a catalytic element located in the housing concentrically with the axis and having an outer surface defining, with the housing outer wall, an outlet volume which increases in size in the direction toward the housing outlet end, an inner surface spaced from the outer surface, defining therein an inlet volume, and defining, adjacent the housing outlet end, a by-pass opening communicating between the inlet volume and the housing outlet, and flow passages extending radially outwardly from the inner surface to the outer surface, communicating, at the inner surface, with the inlet volume, and communicating, at the outer surface, with the outlet volume, and a deflector moveable between a blocking positi

Abstract: A modified in-line adsorber system capable of meeting the California ultra-low emission vehicle (REV) standard using a combination of burn-off catalyst and a modified adsorber constructed with an open flow region of substantially unobstructed flow having a hole or a region of larger cell openings to increase the amount and rate of contact between the exhaust gas and the burn-off catalyst, and thereby reduce the light-off time of the burn-off catalyst. For best effect, the open flow region of the adsorber is positioned along the exhaust stream between the engine and the burn-off catalyst as defined by the exhaust flow path of least resistance.

Abstract: An exhaust gas purification device (10) for trapping combustion engine exhaust emissions, particularly hydrocarbons and particulate matter, is disclosed. The device includes a casing (12) having an inlet (14) for exhaust gases from a combustion engine. The casing (12) houses a filtering and/or adsorbing medium (16), whilst a catalytic converter (22) is arranged downstream of the medium (16). A valve arrangement is provided for controlling exhaust gas flow through the filtering and/or adsorbing medium (16). The casing further includes a throughflow passage (18) adjacent the filtering and/or adsorbing medium (16), the passage running from the upstream end to the downstream end of the filtering and/or adsorbing medium (16). The passage also includes a throttling valve (20) responsive to temperatures in the device.

Abstract: Flow diverter methods and apparatus useful, for example, in adsorber systems capable of meeting the California ultra-low emission vehicle (ULEV) standard, are described, the adsorber systems incorporating a combination of a burn-off catalyst and a modified adsorber constructed with an open flow region of substantially unobstructed flow having a hole or a region of larger cell openings, the flow diverter acting to control exhaust flow through the adsorber to both increase adsorption and reduce the light-off time of the burn-off catalyst.

Abstract: An improved auxiliary heat source for use in an engine cold start emission reduction system includes a flame containment chamber having at least one wall formed of a porous foam material that confines the flame within a predetermined chamber while permitting heat therefrom to emerge and flow to an exhaust system catalyst or, in the case of diesel engines, a particulate trap.

Abstract: Two catalytic converters are disposed in series midway in an engine exhaust passage, and a by-pass valve selectively introduces exhaust into the upstream converter and a by-pass passage which by-passes the converter. When the catalyst temperature of the upstream catalytic converter exceeds a threshold value A, exhaust is routed to the by-pass passage. The catalyst temperature in the state when exhaust is routed to the upstream catalytic converter under steady state engine running conditions is stored as a convergence temperature depending on the engine running conditions.When exhaust is routed to the by-pass passage, exhaust is re-introduced into the upstream converter only when both the catalyst temperature and the convergence temperature corresponding to the running conditions at that time are less than a threshold value B which is less than the threshold value A.In this way, hunting of the by-pass valve operation is prevented.

Abstract: A purification system and a method for controlling exhaust gas emissions from internal combustion engines during start-up and restart, as well as during normal engine operation is disclosed. A method for controlling emissions during low load operation of a diesel engine fueled with a diesel fuel/methane mixture is also provided. Exhaust gases are contacted with a gas permeable solid material containing an adsorbent and a catalyst capable of converting the noxious components into innocuous materials. The flow of the gases through the gas permeable solid material is reversed in a series of continuing cycles to bring or to maintain the catalyst in a temperature range suitable for controlling the noxious components, below which temperature the noxious materials are adsorbed by the adsorbent.

Abstract: An exhaust gas management apparatus including: an air flow directing body forming a bypass passage including an inlet end and an outlet end and defining a low pressure region between the inlet end and the outlet end having a first diameter less than second and third diameters of the inlet and outlet ends, respectively; a hydrocarbon adsorber mounted radially exterior of the air flow directing body; an air source located downstream in an exhaust flow path of the low pressure region of the air flow body; and an air pump forcing air through the air source wherein, during activation of the pump, the bypass passage is valved shut at the low pressure region, wherein less air is required to valve shut the bypass passage than would be required at another location within the bypass passage.

Abstract: A change-over valve unit has a change-over valve for switching a bypass passage and an exhausting passage disposed in parallel therewith. An adsorbent is disposed in the bypass passage to adsorb exhaust components. An actuator of the change-over valve is isolated from an adsorption cylinder by a pedestal. Furthermore, rotary shafts of the control mechanism of the change-over valve are positioned within the bypass passage of the adsorber when the change-over valve is positioned to open the main exhaust passage. Thus, the heat of the exhaust gas flowing through the main exhaust passage is not transmitted to the rotary shafts.

Abstract: In the present invention, the exhaust gas from the engine is divided into a first and a second branch exhaust passages after it passes through a three-way reducing and oxidizing catalyst, and the two branch exhaust passages merge into an exhaust gas outlet passage. In the first branch exhaust passage, an oxidizing catalyst is disposed, and in the exhaust gas outlet passage, a denitrating and oxidizing catalyst is disposed. NO.sub.x in the exhaust gas from the engine is all converted to N.sub.2 and NH.sub.3 by the three-way reducing and oxidizing catalyst and a part of the NH.sub.3 generated by the three-way catalyst flows into the first branch exhaust passage and is converted to NO.sub.x again by the oxidizing catalyst. The amount of NO.sub.x produced by the oxidizing catalyst and the amount of NO.sub.x flowing through the second branch exhaust passage is determined by the flow distribution ratio of the first and the second branch exhaust passages.

Abstract: A diagnostic apparatus for exhaust gas clarification apparatus for internal combustion engine is disclosed. The diagnostic apparatus can diagnoses the individual catalyst independently by means that an air/fuel ratio sensor is mounted before and after the individual catalyst, and that the individual catalyst is diagnosed by estimating the correlation of the output signals from the air/fuel ratio sensors mounted before and after the individual catalyst, and furthermore, that the individual diangosis operation is performed at distinctive operation regions adequate for their corresponding diagnostic mode.

Abstract: An exhaust system for an internal combustion engine includes an exhaust turbocharger, and exhaust emission control with 3-way catalysts. In order to shorten the delay until emission control begins after the engine is started, a first catalytic converter is located in the exhaust line downstream from the turbocharger which is always traversed by the exhaust. Downstream of the turbocharger, a second catalytic converter is arranged that is traversed by exhaust only temporarily, with the second catalytic converter being traversed only until the exhaust system has reached a predetermined temperature.

Abstract: The invention is directed at an engine exhaust system comprising: (1) a honeycomb structure having an inlet and outlet end disposed in a housing located in an exhaust gas stream downstream from an engine, and having a first substantially unobstructed flow region, and a second more obstructed flow region adjacent the first region, both providing a flow path for the exhaust gases in the exhaust gas stream; and, (2) a fluidics apparatus disposed in the exhaust stream comprising a bi-convex diverter body with the respective surfaces located upstream and downstream of each other, located upstream and proximate to the first region, a diversion fluid source and a conduit possessing a rounded outlet for directing the diversion fluid toward the diverter body.

Abstract: A soot filtration device (1) in the exhaust gas section of a diesel internal-combustion engine comprises a housing with an exhaust gas inlet (2) and an outlet (3) for the filtered exhaust gas, a plurality of soot filter cartridges (4) arranged in the housing, and at least one regeneration apparatus (5). The soot filter cartridges (4) are arranged in at least two separate chambers (6), and each of these chambers (6) has a closable inlet opening (7).

Abstract: The present invention is directed to an in-line engine exhaust system. In general, the exhaust system is comprised of the following: (1) a honeycomb structure having an inlet and outlet end disposed in a housing and located in an exhaust gas stream downstream from an engine and possessing a first substantially unobstructed flow region, a second more obstructed flow region adjacent the first region; and, (2) a fluidics apparatus disposed in the exhaust stream proximate to the first region for creating a negative flow zone within the first region, which in turn results in diverting a portion of the exhaust gases away from the first region. More specifically, the fluidics apparatus includes a source diversion fluid, typically air, a conduit for delivering the diversion fluid and a diverter body for diverting the diversion fluid.

Abstract: There is disclosed a diesel particulate filter for filtering exhaust gasses of a diesel engine while collecting particulates and burning them by electric heat. The diesel particulate filter includes at least one filter body disposed in a filter case with filtering passages characterized as coarseness or mesh which gradually changes density of the exhaust flow as it moves from an upstream side toward a downstream side.

Abstract: This DPF apparatus has the main filter and the sub-filter installed in the exhaust gas passage, with an open-close valve provided to the main filter and a bypass valve provided to the sub-filter. A particulate accumulation sensor is also installed in the exhaust gas passage on the inlet side of the main filter. In response to the detection signals from the particulate accumulation sensor and the temperature sensor, the controller operates the open-close valve and the bypass valve and applies electricity to the metal net forming heaters to incinerate collected particulates. The particulate accumulation sensor comprises a detection filter whose ventilation resistance per unit volume is almost equal to that of the filter body, terminals made of a conductive metal and attached to the ends of the detection filter, and a resistance sensor to measure resistance between the terminals.

Abstract: Two flow paths separated by a partition wall having a bore formed downstream of a catalyst unit provided in an exhaust pipe of an internal combustion engine. Adsorption means for adsorbing an HC component of an exhaust gas of the internal combustion engine is provided in one of the flow paths. When a temperature of the exhaust gas is above a predetermined level, the exhaust gas flows through the other flow path by means of a change-over valve. Because the bore is provided in the partition wall, the adsorption means is exposed to the exhaust gas and the HC component adsorbed by the adsorption means is easily desorbed because of the high temperature of the exhaust gas. A one-way valve which repeatedly performs an opening/closing operation due to pulsation of the exhaust gas, is provided between recirculation flow pipes.

Abstract: The invention is directed to a honeycomb structure having an inlet and outlet end disposed in a housing and located in an exhaust gas stream downstream from an engine. The honeycomb structure possesses a first substantially unobstructed flow region, i.e., a low-flow resistance region, and a second more obstructed flow region adjacent the first region for the exhaust gases in the exhaust gas stream. The exhaust system further includes a fluidics apparatus disposed in the exhaust stream proximate to the center of the first region comprising a diverter body, a diversion fluid source and a conduit possessing an outlet for directing the diversion fluid toward the diverter body. Lastly, the diverter body comprises a main body and at least one pair of extensions, preferably symmetrical extensions.

Abstract: In a method and apparatus for reducing hydrocarbon emissions from an internal combustion engine during its cold-starting phase an adsorber, which adsorbs hydrocarbons below a desorption temperature and desorbs them above the desorption temperature, is arranged in a bypass conduit to the exhaust conduit and the exhaust gas is passed through the bypass conduit and the adsorber below the desorption temperature of the adsorber, and the bypass conduit is closed when a catalytic converter arranged close the engine in the exhaust conduit upstream of the bypass conduit reaches operating temperature and remains closed at least until a catalytic converter arranged downstream of the adsorber has reached operating temperature.

Abstract: A engine exhaust system is disclosed for reducing the amount of hydrocarbons emitted during engine start-up (cold-start), before the catalytic converter has attained its effective operating temperature. The system includes a flow diverter, in particular a secondary air jet adapted to direct substantially all of the engine exhaust through a molecular sieve structure during cold-start, and to direct the engine exhaust stream directly from the light-off catalyst to the burnoff catalyst, bypassing the molecular sieve structure after light-off.

Abstract: A multi-cylinder internal combustion engine is provided with a group of constantly operated cylinders and a group of cylinders that can be switched off. An exhaust line having a catalytic converter is associated with each group of cylinders. A shutoff element is disposed downstream of the catalytic converter of the constantly operated cylinder subassembly. In addition, the two exhaust lines or the two catalytic converters are connected to each other via a bypass line. Maintaining the temperature of the second catalytic converter is made possible via the bypass line, even when the cylinders of the second group are not operated and when the exhaust line is closed.

Abstract: A engine exhaust system is disclosed for reducing the amount of hydrocarbons emitted during engine start-up (cold-start), before the catalytic converter has attained its effective operating temperature. The system includes a flow control device, in particular a bi-metallic flap, occupying a first position at the first temperature to direct substantially all of the engine exhaust through a molecular sieve structure to adsorb the hydrocarbons, and a second position at the second temperature, to direct the engine exhaust stream directly from the light-off catalyst to the burnoff catalyst, bypassing the molecular sieve structure.

Abstract: With a method of controlled regeneration of a diesel soot filter of a diesel engine the diesel soot filter is divided into a plurality of sections which are connected in parallel in the exhaust gas tract and into at least one of which the influx of exhaust gas is blocked in response to the exhaust gas temperatures measured downstream of the diesel soot filter. When the maximum admissible exhaust gas temperature downstream of the diesel soot filter is exceeded this section, consequently, is shut off in part or even completely from the exhaust gas stream so that the mass flow rate through the corresponding filter section is reduced or even cut off, while the mass flow rate through the remaining sections is increased in a way so as to again control the regeneration or even discontinue it.

Abstract: A modular catalytic converter and muffler is used to purify exhaust from a relatively large diesel engine. The device includes various structural components that are mounted in the exhaust flow path within a housing having an inlet and an outlet. A plate mounted within the housing divides the housing into an inlet chamber and an outlet chamber. A plurality of catalytic converter sub-cans are mounted across the plate between the inlet chamber and the outlet chamber. A flow distributor is mounted within the housing upstream of the catalytic converter sub-cans. The flow distributor divides and directs a portion of the exhaust to each of the catalytic converter sub-cans. Some muffler structure is mounted within the housing between the catalytic converter sub-cans and the outlet in order to attenuate noise in the exhaust.

Abstract: An emission control system including an auxiliary catalytic converter (50) coupled upstream of a main catalytic converter (44) via a bypass valve (52). Exhaust gas flow is first routed through the auxiliary converter (50) by opening one bypass valve (52) and closing another (48) when an indication of exhaust gas temperature is above a predetermined temperature. An indicating signal is derived from transitions in output of an exhaust gas sensor (58) position downstream of the auxiliary converter (50). Degraded operation of the auxiliary converter (50) is provided when both the indicating signal indicates degraded operation and an indication of inducted airflow exceeds a preselected airflow (324). Degraded operation of one bypass valve (48) is provided when the indicating signal indicates degraded operation and the inducted airflow is below the preselected airflow (340-354).

Abstract: An exhaust system for a spark ignition engine on an automotive vehicle including an exhaust filter disposed downstream of a spark ignition engine for condensing hydrocarbons in exhaust gases from the engine during a first time period after start of the engine, a bypass structure for bypassing at least a portion of exhaust gases around the exhaust filter to heat the exhaust filter during a second time period after the first time period and evaporate the condensed hydrocarbons, and a catalytic converter disposed downstream of the exhaust filter to oxidize the evaporated hydrocarbons and reduce NO.sub.x in exhaust gases passing therethrough. A method is also provided.

Abstract: An apparatus is provided for purifying an exhaust gas discharged from an internal combustion engine, which comprises a first exhaust gas passage including a nitrogen oxide removing catalyst and a three way catalyst, a second exhaust gas passage including the three way catalyst, a gas flow regulator for selectively directing the exhaust gas to the first and second exhaust gas passages, and a control unit which directs the exhaust gas to the first exhaust gas passage (thereby passing exhaust gas first through the nitrogen oxide removing catalyst and thereafter through the three way catalyst) when the temperature of the nitrogen oxide removing catalyst is within a hydrocarbon adsorbing range of temperature thereof while the engine is warming up, and to the second exhaust gas passage (thereby passing the exhaust gas only through the three way catalyst) when the temperature of the nitrogen oxide removing catalyst exceeds the hydrocarbon adsorbing range of temperature thereof.

Abstract: With a V type engine, the exhaust air-fuel ratio is detected for each bank, and is also detected downstream of a catalytic converter which takes the combined exhaust flow from each bank. An air-fuel ratio feedback correction coefficient .alpha. is proportional-plus-integral controlled separately for each of the banks based on the air-fuel ratio detected for each of the banks, while a correction value PHOS for a proportional portion is set commonly for each of the banks, based on the air-fuel ratio detected downstream of the catalytic converter. Here the correction value PHOS is converted to separate correction values PHOSR, PHOSL for each of the banks corresponding to a change rate of the air-fuel ratio feedback correction coefficient .alpha. to an initial value, and the proportional operating amount of the proportional-plus-integral control which is carried out separately for each bank, is corrected based on the converted correction values PHOSR, PHOSL.

Abstract: A catalyst is integrated into a cylinder block of an engine and positioned near at least one exhaust port thereof. A separation wall is provided for dividing the exhaust flow into two branches, one of which contains the catalyst. A control device responsive to at least one engine parameter selectively seals one of the branches such that exhaust is either passed through the catalyst or around the catalyst. A coolant passage is provided adjacent the catalyst to prevent overheating.

Abstract: A diesel engine exhaust gas recirculation system for control of NO.sub.x emissions is disclosed in hi h total particulate (soot, condensed polynuclear aromatic and aliphatic hydrocarbons, and ash) control system is employed to filter the exhaust gas prior to reintroduction to the diesel engine. By cleaning the recirculated exhaust gas of substantially all particulates, wear on the engine due to particulate abrasion is minimized, and NO.sub.x and particulate emissions are reduced. The particulate control system includes a high efficiency ceramic monolith trap that is periodically regenerated by one or more pulses of high-pressure air that move in the opposite direction of the engine exhaust flow through the trap. In one embodiment, a portion of the filtered diesel exhaust is recirculated to the engine. In a further embodiment, the particulate control system filters a portion of the diesel exhaust in the recirculation flow path. The system can retrofit any existing diesel-powered equipment.

Abstract: An automotive internal combustion engine is equipped with a hydrocarbon adsorber for the purpose of controlling the emissions of unburned hydrocarbons from the vehicle's tailpipe. Regeneration of the adsorber is achieved by an electronic engine controller operating an air pump and a sample pump, using information from an exhaust gas oxygen sensor.

Abstract: An exhaust-gas purification device for an internal combustion engine or the like which can effectively purify hydrocarbon (HC) among the toxic components of the exhaust-gas emitted by the engine or the like even when the temperature of said exhaust-gas is relatively low, and an exhaust-gas purification device, wherein, in an exhaust system in which a first purification-treatment section 4 carrying a catalyst 3 is placed in a main exhaust passage 2, a bypass passage 5 is placed which diverges from said main exhaust passage 2 and which later returns to said main exhaust passage 2 at a certain distance, and a second purification treatment section 7 carrying an absorbent 6 is placed in said bypass passage 5.

Abstract: A very compact arrangement of a catalyst bed and exhaust gas bypass passage for a catalytic converter assembly having an essentially overall oval shape with the catalyst bed and bypass passage essentially parallel and side-by-side, and a multi-wing butterfly valve alternately seatable to close one of the passages while opening the other, and vice-versa.

Abstract: The valve shaft passes through a journal bearing in the wall of the valve body to an actuating lever attached to the shaft on the outside of the valve body. This journal bearing is sealed by an arrangement of several parts to prevent escape of exhaust gases. These parts include a bellows and ceramic thrust washers. By making the valve shaft axis non-perpendicularly intersecting the axis of the valve body wall, the entire circumference of the valve blade can be sealed to the valve body wall when the valve is closed.

Abstract: An apparatus and method suitable in controlling a level of noxious fumes and visible smoke discharging from diesel engine exhaust gases. In a purification mode, a stream of relatively dirty exhaust gases and discharged cooling liquid from the engine are mixed together; liquid entrained in the mixture and particulate matter in the mixture are then removed and noxious substances in the resulting exhaust gases are adsorbed. In a regeneration mode, the exhaust gas is relatively clean so that streams are kept apart to avoid mixing so that the exhaust gases can adsorb the previously adsorbed noxious substances. The purification mode arises when the marine diesel engine is running at slow speed and combustion takes place inefficiently. The regeneration mode arises when the marine engine is running at high speed and combustion takes place efficiently or else noxious substances have been adsorbed substantially to capacity.

Abstract: An engine exhaust emission control system, in which a valve is set at a hydrocarbon adsorbing position to guide exhaust emissions to a bypass line including an adsorbent sieve for adsorbing hydrocarbons during a initial period of engine start-up, and the valve is switched over to a hydrocarbon purging position to guide exhaust emissions to an exhaust line and to divert a part of the exhaust emissions to the bypass line.

Abstract: A flow-through particulate incineration system is coupled to an aerodynamically regenerated diesel engine exhaust gas particulate (soot, condensed polynuclear aromatic and aliphatic hydrocarbons, and ash) trap. An incineration chamber is provided downstream of the particulates dislodged from the particulate trap during regeneration thereof by a pulse of compressed air. During regeneration, a valve between the particulate trap and the incineration chamber opens to allows the air and entrained particles to pass into the incineration chamber. A secondary filter is mounted within the incineration chamber to allow passage of the regeneration air therethrough, but prevent passage of the particulates, whereby the particulates are retained in the incineration chamber. A heater in the incineration chamber is periodically activated to burn the particulates collected in the trap. The oxidation products may be exhausted to ambient or may be returned to the engine intake in an exhaust gas recirculation system.

Abstract: In an exhaust purification apparatus of an internal combustion engine having an NOx absorption and release material in an exhaust conduit, a heater is provided close to the NOx absorption and release material. When an NOx absorption operation continues for a predetermined period, the heater is switched on to raise the temperature of the NOx absorption and release material above a predetermined temperature, for example, 500.degree. C. When the temperature of the NOx absorption and release material is high, the NOx absorption and release material releases absorbed NOx and is regenerated.

Abstract: A control system for controlling operation of an internal combustion engine detects a selected one of two exhaust modes: a first exhaust mode in which exhaust gases are guided through a first catalytic converter upstream of a second catalytic converter, and a second exhaust mode in which exhaust gases are guided through a bypass passage bypassing the first catalytic converter. A control mode is determined according to the selected one of the two exhaust modes, in which the operation of the engine is to be controlled by the control system.

Abstract: An apparatus for controlling temperatures of catalytic converters in an exhaust system of an internal combustion engine. The exhaust system includes a light-off catalytic converter and a main, or underbody, catalytic converter. The light-off catalytic converter is smaller and is disposed nearer to the engine than is the main catalytic converter so that it can be brought to an efficient operating temperature by engine exhaust gases in less time than can the main catalytic converter. This reduces the output of initial undesirable exhaust emissions during start-up periods when the engine and exhaust system components are relatively cold. A valve controls the flow of exhaust gases through each of the two catalytic converters to bring them most quickly to, and maintain them at, their most efficient operating temperatures.

Abstract: A plurality of lean NOx catalysts are installed in passages of a dual passage portion of an exhaust conduit of an internal combustion engine. A space velocity changing means including a valve is provided at a connecting portion of the passages so that the amount of exhaust gas flowing through the lean NOx catalysts is altered periodically. When a space velocity of exhaust gas at the lean NOx catalyst changes from a low velocity to a high velocity, an NOx purification rate of the lean NOx catalyst increases momentarily. By repeatedly generating the NOx purification rate increased conditions, the NOx purification rate of the NOx purification apparatus including the plurality of lean NOx catalysts is greatly increased.