Abstract: A core element for use in a catalytic converter, especially an electrically heatable catalytic converter, which core element is characterized by a corrugated thin metal strip having metal tabs attached to each end. The tabs are bent along one or more lines normal to the edges of the corrugated thin metal strip. When bent along one line, for example, an angular tab is formed. When the tabs are bent along an infinite number of lines a uniform amount, a circular segment is formed. A catalyst is deposited on one or both surfaces of the corrugated thin metal strips. A central portion of each strip is flat to enable location between the legs of a bifurcated central pin. The central pin with a group of such corrugated thin metal strips is then spirally wound about the central pin to provide a core with overlapped curved tabs defining at least two discrete generally spiral groups of resistance strips electrically isolated from each other.

Abstract: The invention pertains to a honeycomb body which can be electrically heated. Heating power is non-homogeneously distributed in the monolith. The honeycomb body is formed from at least one layered metal sheet which is wound or layered and intertwined. A multiplicity of flow channels for a fluid are provided. Each of the flow channels have openings at the two mutually opposite end faces of the honeycomb body. At least one current path is formed in the layers with an electrical resistance which is non-homogeneously distributed along the length of the path. The path can carry a current for heating the honeycomb body. According to the invention, the current path has an electrical resistance which is always adapted to the requirements of the voltage source to which the honeycomb is to be connected for the purpose of heating the same.

Abstract: The present invention relates generally to apparatus and methods used in chemically reducing pollutants in effluent gas flow. More particularly, the present invention relates to ionization of effluent gas from an effluent gas source by passage of the effluent gas through a resonance field, and potentialization and purification of the effluent gas by passage of the effluent gas through a continuous electrical arc. Preferably, the resonance field and the continuous electrical arc are both generated by an alternating current. The result of using the apparatus and method of the present invention is a release of stabilized air particles without a high consumption of energy, and without producing waste products requiring subsequent collection.

Abstract: A convection-based device having no moving parts, which effectively catalytically removes volatile organic compounds from an ambient airspace. The device has, located within a vented housing, a catalytic structure designed to allow air to pass through it. The catalytic structure is heated by electric current and maintained to a predetermined temperature. Air enters the bottom of the device, passes through the catalytic structure, where the volatile organic compounds in the air are reduced, and exits the top of the device.

Abstract: A spent sterilization agent destruct and ambient air mixing device for inclusion with medial instrument sterilization system that preferably utilizes humidified ozone O.sub.3 as a sterilization agent or sterilizing effluent. The invention is for receiving a spent sterilization agent flow that includes humidified ozone O.sub.3 and oxygen O.sub.2 and provides, within the device, for exposure of that spent sterilization agent to both a catalytic converter and to an application of heat that converts ozone O.sub.3 to oxygen O.sub.2, thereby rendering the sterilization agent inert, and provides for mixing that inert flow with ambient air and venting to atmosphere.

Abstract: A catalytic converter arrangement incorporated in an exhaust system of an internal combustion engine includes an exhaust manifold for ducting emissions from the engine; and first and second catalytic converters. The first catalytic converter is connected to and positioned immediately downstream from the exhaust manifold. The first catalytic converter has a ceramic catalyst support on an upstream side thereof and a metal catalyst support on a downstream side thereof. The second catalytic converter is connected to the first catalytic converter through an exhaust pipe and positioned downstream from the first catalytic converter. The second catalytic converter has a ceramic catalyst support. Thus, overheating of the metal catalyst support of the first catalytic converter can be prevented due to absorption of heat from emissions by the ceramic catalyst support of the first catalytic converter.

Abstract: A honeycomb body assembly, in particular a catalyst carrier body, comprises at least one electrically heatable honeycomb body having layered metal sheets forming a stack with a plurality of channels through which a fluid can flow. The metal sheets have a thickness of about 0.03 to 0.12 mm. The honeycomb body is electrically subdivided with regard to its cross-section and/or in its axial direction. At least one electric current path is formed through the metal sheets with an electric resistance of between 0.01 and 2 .OMEGA.. The resistance, which is dependent on the temperature, can be used for monitoring and regulating the honeycomb assembly.

Abstract: An exhaust system for an internal combustion engine adapted to correct the problem of pollution occurring at start-up and during at least initial engine running, and characterized by an electrically heatable catalytic converter and, desirably, a separate unheated conventional catalytic converter in tandem relation. The system also provides means for providing electrical power greater than 500 watts for 2 seconds or more whereby the temperature of the catalyst is raised and maintained at least 650 F. An advantage of preferred embodiments is that there is provided a substantially improved means for augmenting conventional catalytic converter exhaust systems for modern requirements by inserting in the exhaust system an electrically heatable catalytic converter for conversion of pollutant material operative prior to, during and after start-up.

Abstract: There is provided a terminal especially adapted for use with an electrically heatable catalytic converter having a stud, a portion of said stud being coated with a thin layer of refractory metal oxide, and a sleeve having an interference fit with said coated portion of said stud, said stud adapted to be welded at its proximal end to one side of a resistance circuit. There is also provided an electrically heatable catalytic converter including such terminal.

Abstract: A honeycomb heater has a honeycomb structure having a number of passages defined by partition walls, at least two electrodes in electrical contact with the honeycomb structure, a catalyst composition formed on partition walls of the honeycomb structure, including zirconia powder loaded with Rh, an inorganic heat-resistant oxide and a rare earth element oxide. A catalytic converter has at least one or two main monolithic catalyst(s) and a honeycomb heater disposed upstream, downstream or between the main monolithic catalysts.

Abstract: The honeycomb heater has a structure that the first corrugated heater and the second flat heater are alternately and vortically wound to make the value of the resistance of the first corrugated heater from one end to the other end equal to that of the second flat from one end to the other end. The second flat heater has a mesh shape. Consequently, the honeycomb heater of the present invention has no deformation of heaters caused by piling of corrugated heaters and has a larger area of heater per unit area.

Abstract: An HC adsorbent and a first three-way or oxidation catalyst are installed in an exhaust conduit of an internal combustion engine in that order in a flow direction. A second three-way or oxidation catalyst is installed upstream of the HC adsorbent in the exhaust conduit. When the exhaust gas flows through the second catalyst, the thermal energy of the exhaust gas is compensated for warming-up the second catalyst in a cold period. As a result, the warming-up of the HC adsorbent is delayed and the HC adsorbent can adsorb the HC included in the exhaust gas for a relatively long period. After the second catalyst has been warmed-up, the HC included in the exhaust gas flowing into the HC adsorbent is oxidized. As a result, the HC adsorbent is prevented from being saturated for a short period of time.

Abstract: The disclosure relates to an improved catalytic converter core which is characterized by a plurality of spaced rigid centrally located pins about which are wrapped a plurality of corrugated thin metal strips. The configuration of the resulting core is determined by the number of centrally located pins, for example, with two pins the configuration is oval. Electric power may be selectively applied to effect heating of the core. Catalyst may be applied to the surface or surfaces of the corrugated thin metal strips to aid in converting undesirable materials in a gas stream to more acceptable materials.

Abstract: A conical microlith catalyst reaction system for use in automotive catalytic converters or gas turbine catalytic combustors advantageously utilizes a microlith catalyst bed formed from a wire cloth (10) woven into a spiral wound flat helix (or coil). The spiral windings of the wire cloth helix are wound to form a uniform angle less than 90.degree. relative to a ceramic housing formed from an inner ceramic hub (102) and an outer ceramic shroud (104). Warp wires (12) further carry electrical current via bus bars (106, 108) for electrically heating the catalyst bed. Lightoff time for the bed is significantly reduced due to the heating. The angled spiral windings create the conical shape to prevent buckling of the spiral windings due to thermal stress caused by the microlith catalyst bed becoming hot.

Abstract: A heater is composed of (a) a honeycomb structure having a large number of passages, (b) an adsorbent composed mainly of zeolite or an adsorbent-catalyst composition comprising adsorbent and a catalyst component supported on the adsorbent, the adsorbent or adsorbent-catalyst composition being coated on the honeycomb structure and (c) at least two electrodes fixed to the honeycomb structure for electrification of the honeycomb structure, wherein a gas is flowed through the passages in the honeycomb structure and is heated. A catalytic converter has at least one main monolith catalyst and the above heater provided upstream or downstream of the main monolith catalyst or between two main monolith catalysts.

Abstract: A catalyst carrier body has a honeycomb element with walls defining a multiplicity of channels through which a gas can flow. The honeycomb element has a catalytically active surface layer. The active surface layer is electrically heated for improving cold-starting properties and/or to raise the operating temperature in the catalytic converter.

Abstract: A resistance-adjusting-type heater including a honeycomb structure having a large number of passages and at least two electrodes provided on the honeycomb structure for energizing the honeycomb structure. The honeycomb structure has a slit or slits which form a predetermined angle to the partition walls of the honeycomb structure so as to enable adjustment of resistance between the electrodes, so that gas flowing through the passages of the honeycomb structure is heated.

Abstract: A metal substrate contains a barrier which functions as an electrical insulator. One can thus use the substrate to make an electrically heated catalytic converter, in which one must electrically isolate a catalyst-bearing strip from adjacent strips. One forms the substrate by first coating the substrate with a thin first layer of alumina washcoat and heating the substrate to a temperature of about 800.degree. to 1000.degree. C. This heating step produces the barrier, which may constitute a spinel. One can then apply a catalyst to the substrate, either by applying one or more secondary layer(s) of washcoat, having greater thickness than the first layer, and impregnating the second layer with the catalyst, or by coating the substrate with a washcoat which already contains the catalyst. Alternatively, one can omit the step of applying the catalyst, and can use the strips to form a heater for a stream of gas. One can use the heater in conjunction with a main catalytic heater, or as a stand-alone heater.

Abstract: A method for treating engine emissions and a device for treating engine emissions and dampening engine noise are provided. The invention provides for multiple zones of reaction so as to treat reducible emission components by providing a low oxygen, relatively cool reducing zone and also to treat oxidizable emission components by providing a relatively high oxygen, hotter oxidizing zone. A feature of the invention includes a heating means situated adjacent to or embedded into an oxidizing catalyst or an oxidation zone of a three-way catalyst.

Abstract: In a catalytic converter operating method according to the present invention, a heater is energized at a predetermined power level or above and thereby heated substantially concurrently with the operation of an engine. During the heating, an oxidizing gas is introduced into the catalytic converter. When the temperature of the heater exceeds a value at which a main catalyst of the catalytic converter or a light-off catalyst carried on the heater functions, the power level is reduced by an output adjuster and supply of the oxidizing gas is suspended.

Abstract: There is provided a novel and improved core element for a catalytic converter characterized in that the core element has a corrugated thin metal strip with bent tab members at each end, such tab members being in two portions. These two portion sandwich the ends of the corrugated thin metal strip therebetween and provide a convenient means for welding the ends of the corrugated thin metal strip to the tab members. A plurality of such corrugated strips with the tab members attached are tightly spirally wound about a central post or pin and the tab members are dimensioned to overlap and ultimately define a shell segment. The shell segments define a core which is encased in a suitable housing to form a catalytic converter which may be electrically heatable. An electrically heatable catalytic converter is especially useful to remove pollutants from internal combustion engine exhaust gas.

Abstract: An exhaust emission control apparatus includes an absorbent provided in an upstream portion of an exhaust passage of an engine to absorb hydrocarbon in exhaust gas passed through the exhaust passage at a temperature lower than a predetermined first temperature, the hydrocarbon being desorbed from the absorbent at a temperature higher than the first temperature, a catalytic converter provided in a downstream portion of the exhaust passage to purify hydrocarbon in the exhaust gas when a catalyst of the catalytic converter is active, the catalyst of the catalytic converter being activated at a temperature higher than a predetermined second temperature, the second temperature being higher than the first temperature, and a heating part for heating the catalytic converter to a temperature higher than the second temperature when the engine is in a prescribed starting condition and the absorbent is at a temperature higher than the first temperature, so that the hydrocarbon desorbed from the absorbent in the exhaust p

Abstract: A plate type shift converter comprises a stack of alternately piled shift reactor plates and cooling plates and various gas intake and exhaust manifolds mounted on lateral faces of the stack. Each shift reactor plate includes a plate member, a masking frame provided along the periphery of the plate member, a gas entrance formed in the masking frame, a gas exit formed at a location opposite the gas entrance in the masking frame and a shift catalyst located in the masking frame. Each cooling plate includes a plate member, a masking frame provided along the periphery of the plate member, a gas entrance formed in the masking frame, a gas exit formed at a location opposite the second gas entrance in the masking frame and a fin plate located in the masking frame. When gases are introduced to the shift reactor plate, the gases undergo the CO shift reaction (exothermic reaction) as they flow contacting the shift catalyst.

Abstract: A honeycomb heater having integrally formed and/or integrally sintered electrodes constructed of a metallic honeycomb structure having a desired honeycomb configuration, and metallic electrodes which are integrally sintered with the honeycomb structure at predetermined positions thereon. The honeycomb heater having integrally sintered electrodes is manufactured by joining or contacting the electrode-like formed bodies to the formed honeycomb body, and then by sintering the formed honeycomb body with the electrode-like formed bodies attached or contacted thereto. The electrodes are made of the same material as that of the honeycomb body, or of a material having an electric resistance lower than that of the material comprising the honeycomb body.

Abstract: The catalytic converter includes a first flow passage for an automotive exhaust gas and a second flow passage disposed parallel to the first flow passage to bypass the exhaust gas therethrough. The first flow passage contains a honeycomb heater or a heater catalyst which comprises a honeycomb heater with a catalyst carried thereon. At the beginning of an operation of any engine, the exhaust gas whose temperature is low is caused to flow through the first flow passage. When the temperature of the exhaust gas exceeds a predetermined value, the flow passage is switched from the first passage to the second flow passage.

Abstract: A device for controlling the heating of a catalyst arranged in the exhaust passage of an engine. When the engine is started, the catalyst is rapidly heated by the heater, and the time for which the power is supplied to the heater is increased as the degree of deterioration of the catalyst becomes greater, to thus increase the temperature of the catalyst to the activation temperature thereof when the power supply to the heater is stopped regardless of whether the catalyst is new or has deteriorated.

Abstract: An electrically conductive cellular or honeycomb structure wherein the structure is heated to light off exhaust gases and/or to burn off deposited carbon particulates and thus periodically regenerate the structure. Electrodes attached to the surface of the structure or body pass electrical currents through the body, the currents causing temperature increase by resistance heating. The electrodes are radially or angularly spaced around the outer surface of the structure, near its input end face to thereby achieve a uniform temperature distribution at the input end face for quick light-off and/or for more complete combustion of the carbon particulates. This temperature distribution can also be made more uniform by the distribution of plugs of varying thickness and/or resistivity in selected areas of the input end face of the structure. The structure can be of the porous wall type wherein alternate passageways are plugged at the front and rear faces. The structure may be also formed of an aluminum iron alloy.

Abstract: An electrically regenerable diesel particulate trap or filter comprising an electrically resistive expanded metal sheet or sleeve which when energized heats the filter element to a temperature sufficient to allow the trapped soot particulates to burn.

Abstract: A method for operational monitoring of a catalytic converter of an exhaust system of an engine includes selecting at least two measurement locations at three-dimensionally spaced-apart cross-sectional regions of the exhaust system, and defining at least a partial volume of the catalytic converter between the locations being definitive for catalytic conversion of pollutants in the exhaust gas. The temperature at the regions is measured and monitored and the temperature at least at one of the locations is measured integrally over an approximately representative portion of at least one region and not spotwise. An apparatus for operational monitoring includes at least two temperature sensors disposed successively in flow direction in at least two regions of the exhaust system, defining at least the partial volume of the catalytic converter. At least one of the sensors integrally measures temperature over an approximately representative portion of the region in which it is disposed.

Abstract: A mounting assembly is disclosed for a metallic honeycomb resistance heater structure wherein a pair of complementary ceramic honeycomb structures are utilized on opposite sides of the metallic honeycomb structure to not only mechanically support the same within an enclosing housing, but also to electrically insulate the resistance heater from such housing.

Abstract: A catalytic air cleaner purifies air in enclosed spaces, such as in an aircraft or spacecraft. The air cleaner includes a pair of metal strips, wound into a double spiral. The strips have projections, affixed to the strips, to maintain the spacing between turns of the spiral. The spiral defines a core which accommodates an electrically heated catalytic converter. The strips themselves have no catalyst coating. A pair of ports at the periphery of the spiral allows air to enter and leave the spiral through inlet and outlet channels. Air entering the spiral through the inlet channel receives heat, by heat exchange, from air leaving the spiral, and then enters the core, where the electrically heated catalytic converter burns off various impurities. The air then leaves the spiral through the outlet channel, and becomes cooled by transferring its heat to the incoming air.

Abstract: In the typical embodiment described in the specification, the exhaust system of an internal combustion engine has two exhaust lines with corresponding catalyst assemblies, each assigned to one group of combustion chambers. During the cold start of the engine, an electric heater included in one of the exhaust lines heats exhaust gases flowing to a first catalyst assembly and the catalyst assemblies are connected in series so that the exhaust gases supplied to the second catalyst assembly are received from the first catalyst assembly. In addition, the ignition point of the engine is retarded after idling speed is reached. To avoid overheating of the catalyst assemblies, the catalyst assemblies receive exhaust gases only after their start-up temperatures are reached from the groups of combustion chambers associated with them and an exhaust cooling line is provided to cool exhaust gases flowing to the first catalyst assembly.

Abstract: An efficient, economical, compact diesel particulate filter comprising a casing comprising a plurality of perforated, supported, rigid tubes wherein the perforated surface of each tube is covered by a filtering element comprising substantially helically cross-wound inorganic yarn, and wherein the yarn is cross-wound to provide four-sided openings.

Abstract: An efficient, economical, compact diesel particulate trap has a plurality of perforated hollow tubes, on each of which a heat-resistant yarn is helically cross-wound to provide a plurality of layers that function as a filtering element. The yarn, which preferably is a continuous-filament ceramic yarn, has a core from which filaments or fiber segments project outwardly and intermesh with fiber segments of laterally spaced cores to provide traps. The cores of yarn convolutions of at least one layer are laterally offset from the cores of convolutions of an adjacent layer to deflect into tortuous paths gases flowing generally radially through the filtering element.

Abstract: A honeycomb monolith heater including a honeycomb structure having a plurality of passages of square or rectangular cross-sectional shape and a plurality of electrode plates fixed to the outer wall of the honeycomb structure, in which the electrode plates are arranged so that the angle formed by the electrode plates and the passage walls is an acute angle. A honeycomb monolith heater assures uniform heat generation and which has improved mechanical properties.

Abstract: A microlith catalyst bed for use in automotive catalytic converters or gas turbine catalytic combustors. The microlith catalyst bed of the present invention advantageously utilizes a wire cloth (10) woven to form a spiral wound flat helix (or coil). Woof wires (14) are woven into warp wires (12) in a polar weave pattern. There is no leftover scrap when forming the microlith catalyst bed. Warp wires (12) further carry electrical current via bus bars (106, 108) for electrically heating the catalyst bed. Lightoff time for the bed is significantly reduced due to the heating.

Abstract: There is provided an improved reinforced corrugated thin stainless steel strip in which either or both of the longitudinal edges are overfolded to increase the thickness and stiffness of the foil to better resist the tendency to failure in a severe hot-shake screening test. There is also provided a core and an electrically heatable catalytic converter containing the core for use in the exhaust line of an internal combustion engine.

Abstract: There is provided a terminal especially adapted for use with an electrically heatable catalytic converter having a stud, a portion of said stud being coated with a thin layer of a ceramic, and a sleeve having an interference fit with said coated portion, said stud adapted to be welded at its inner end to one side of a resistance circuit. There is also provided an electrically heatable catalytic converter including such a terminal.

Abstract: A catalytic converter suitable for use in controlling automotive exhaust emissions including honeycomb heaters which are respectively disposed upstream and downstream of a main monolithic catalyst. Each honeycomb heater includes a honeycomb structure with at least two electrodes provided thereon to supply a current to the honeycomb structure.

Abstract: There is provided an improved electrically conductive metal honeycomb body having a plurality of corrugated thin metal strips, which may be heater strips, extending in electrical parallel between otherwise electrically isolated connector plates. The corrugated thin metal strips each have a flat central section. A first group of strips is gathered at their flat middle portions and bent around one of a pair of rigid central posts, and a second group of strips is gathered and bent in the opposite direction about the other of posts. Insulation in the form of a flexible woven ceramic fiber strip isolate the first and second groups from each other and from the central posts. The connector plates define a segmented retainer shell about the body. A battery is connected to the connector plates whereby current flows from one connector plate through corrugated thin metal strips to the other connector plate and back to the battery.

Abstract: A catalytic converter suitable for use in controlling automotive exhaust emissions including a honeycomb heater disposed downstream of a main monolithic catalyst or between main monolithic catalysts. The honeycomb heater includes a honeycomb structure with a catalyst carried thereon and with at least two electrodes provided thereon to supply a current thereto. A catalytic converter also includes a monolith catalyst for ignition which is disposed downstream of the honeycomb heater. A catalytic converter includes, in place of the honeycomb heater and the monolithic catalyst, a module which is composed of a catalyzed light-off honeycomb heater or of a honeycomb heater and a light-off monolithic catalyst. The module is removably disposed upstream or downstream of a main monolithic catalyst, or between main monolithic catalysts.

Abstract: A resistance adjusting type heater including a honeycomb structure with at least two electrodes provided thereon to supply a current to the honeycomb structure and with resistance adjusting elements provided between the electrodes. The resistance adjusting elements are formed such that a cross-section of a heating portion of the heater is substantially the same as that of a main monolithic catalyst. A catalytic converter includes the resistance adjusting heater which is disposed upstream of a main monolithic catalyst or between main monolithic catalysts. Also, the catalytic converter includes a resistance adjusting heater which is disposed downstream of a main monolithic catalyst. This resistance adjusting heater comprises a honeycomb structure with a catalyst carried thereon, with at least two electrodes provided thereon to supply a current to the honeycomb structure and with a resistance adjusting elements provided between the electrodes.

Abstract: A catalytic converter includes a housing and a catalyst support disposed in the housing. The catalyst support includes a central electrode, a generally cylindrical honeycomb structure and a hollow cylindrical electrode disposing therein the honeycomb structure. The honeycomb structure includes first, second and third metal sheets which are spirally wound about the central electrode and corrugated in shape. The first metal sheet has an inner end electrically connected to the central electrode and an outer end electrically connected to the hollow cylindrical electrode. The radial distance between the central electrode and the second metal sheet is different from that between the central electrode and the third metal sheet. The third metal sheet is spaced away from an imaginary solid having a surface defined by imaginary straight lines extending from an axis of the central electrode in a radial direction and passing through a periphery of the second metal sheet.

Abstract: In a catalytic converter operating method according to the present invention, a heater is energized at a predetermined power level or above and thereby heated substantially concurrently with the operation of an engine. During the heating, an oxidizing gas is introduced into the catalytic converter. When the temperature of the heater exceeds a value at which a main catalyst of the catalytic converter or light-off catalyst carried on the heater functions, the power level is reduced by an output adjuster and supply of the oxidizing gas is suspended.

Abstract: A resistance adjusting type heater has a honeycomb structure having a large number of passages, at least two electrodes to enable electrical heating of the honeycomb structure provided on the honeycomb structure, and a resistance adjusting means, a slit, provided between the electrodes. The thicknesses of passage walls at the portions of the honeycomb structure at which electricity flows at a very high density are increased with a conductive material to prevent the abnormal heat generation at the portions of the honeycomb structure.

Abstract: A resistance adjusting type heater including a honeycomb structure, electrodes provided on the honeycomb structure, and slits as a resistance adjusting device provided between the electrodes, a sealing device for sealing a heat-non-generating portion of the honeycomb structure, wherein a gas is introduced into the passages of the heat-generating portion of the honeycomb structure and is heated. With this heater, the entirety of the exhaust gas introduced into the heater can be heated rapidly thereby ensuring excellent purification efficiency.

Abstract: A honeycomb heater having integrally formed and/or integrally sintered electrodes comprises a honeycomb structure having a desired honeycomb configuration, and electrodes which are integrally sintered with the honeycomb structure at predetermined positions thereon. The honeycomb heater having integrally sintered is manufactured by joining or contacting the electrode-like formed bodies to the formed honeycomb body, and then by sintering the formed honeycomb body with the electrode-like formed bodies attached or contacted thereto. The electrodes are made of the same material as that of the honeycomb body, or of a material having an electric resistance lower than that of the material comprising the honeycomb body.

Abstract: Novel method and structure is disclosed for strengthening and mounting sloted metallic honeycomb structures by positioning rod members within the slots to prevent the slots from closing or deforming, and by utilizing the rod members to precisely engage positionable restraining inserts of an enclosing housing, so as to accurately mount the honeycomb structure within the housing.

Abstract: A resistance heater according to the present invention comprises a honeycomb structure having a large number of passages. The honeycomb structure is provided with at least two electrodes through which a current is supplied thereto. The honeycomb structure also has a means to attain a current density of 5 A/mm.sup.2 or above between the electrodes such as slits within the honeycomb structure. A current is supplied between the electrodes at a current density of 5 A/mm.sup.2 or above.

Abstract: A device for controlling the heating of a catalyzer arranged in the exhaust passage of an engine. When the engine is started, the catalyzer is rapidy heated by the heater, and the time for which the power is supplied to the heater is increased as the catalyzer use period becomes longer, to thus increase the temperature of the catalyzer to the activation temperature thereof when the power supply to the heater is stopped regardless of whether the catalyzer is new or has deteriorated.