Abstract: An apparatus for reducing the amount of electrical power needed to attain light-off of a catalytic converter, particularly a catalytic converter for internal combustion engines. In addition to a resistance-heated catalytic converter, means are provided for varying the air/fuel ratio in the exhaust gas system for the purpose of reducing the ignition temperature of the exhaust gas stream, thereby further reducing the electrical energy required to attain light-off during cold-start.

Abstract: This invention relates to a method for controlling the conductance of heated structures used to initiate faster light-off in emission control systems such as used for automotive catalytic converters, diesel particulate filters and industrial stacks and other applications in which the exhaust gas stream temperature is too low to initiate fast light-off. The invention also relates to a method for minimizing the amount of conductive material used for making such structures.

Abstract: This invention relates to a resistive heating device. In particular, it relates to an exhaust gas apparatus useful for achieving early light-off of catalytic converters comprising a cellular substrate having a layer of conductive material formed thereon and means for activating the device by passing electric current or by exposing the device to an electromagnetic energy field.

Abstract: An extrusion die is used for producing ceramic honeycomb materials. It is particularly useful in producing such extrudates in sheet form by configuring the die in the form of a cylinder and providing a cutting device proximate to the exterior of the cylinder so that when relative rotation is imparted between the cutter and the cylinder, a honeycomb sheet is removed. A cover can be provided over the exterior surface of the cylindrically-shaped die to permit formation of honeycomb extrudates in pellet form.

Abstract: A method of forming an extrusion die fabricated from sinterable ceramic or metal powders, for use in forming honeycomb monolith structures including machining of the die in the green state or after partial densification. Alternatively, all or part of the machining can be performed after full densification or sintering.

Abstract: An dome-shaped extrusion die for use in forming honeycomb monolith structures is disclosed. The die is formed by deforming an extrusion die having a flat cross section to obtain a dome-shaped cross section. Alternatively, the die may be fabricated from sinterable ceramic or metal powders in which case the holes and slots may be formed either in the green state, or in a chalk-hard state after partial densification.

Abstract: This invention relates to a method for controlling the conductance of heated structures used to initiate faster light-off in emission control systems such as used for automotive catalytic converters, diesel particulate filters and industrial stacks and other applications in which the exhaust gas stream temperature is too low to initiate fast light-off. The invention also relates to a method for minimizing the amount of conductive material used for making such structures.

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 improved method for encasing objects in metal is disclosed as are the novel encased objects so prepared. An object is wrapped with a sheet comprising sinterable particulate or powdered metal and an organic binder, and is the fired to volatilize the binder and to sinter the particulate metal into a unitary metal structure. In the preferred embodiment of this invention, the object to be encased is a green sinterable particulate object which undergoes sintering simultaneously with the particulate metal casing during the firing step.

Abstract: A tubular capacitor is formed as follows. A ceramic tube comprising an outer ceramic cylinder and a plurality of radial walls is extruded. The extruded body may also include a second ceramic cylinder coaxial with the first. The one or more cylinders and the radial walls form a plurality of longitudinal passages. After the extrudate is fired and cut, the surfaces of the passages and the remaining surfaces of the cylinder or cylinders are metallized. Selected regions of metalization are removed to form discrete electrodes. Two sets of electrodes are respectively connected to first and second electrical termination means.

Abstract: Ceramic honeycombed structures comprise open-ended cells formed by discontinuities in the cell walls, which discontinuities extend longitudinally through the structure and transversely through the cell walls. The axial discontinuities which enhance the thermal shock resistance of the structures may be formed during extrusion by obstructing the flow of extrudable material through an extrusion die at predetermined locations.

Abstract: Coarse porosity is imposed in fired ceramic bodies containing cordierite (2MgO.2Al.sub.2 O.sub.3.5SiO.sub.2) primary phase by substituting pyrophillite, kyanite, quartz, or fused silica in the batch composition in place of the usual raw talc or clay or a portion thereof.