Abstract: A component of a thermal processing apparatus for a fluid stream of hydrocarbons, a precursor glass for a glass-ceramic coating on such component, and a method of inhibiting deposition of a material, such as carbon, on a surface of the component.

Abstract: A sensor for measuring the non-methane HC concentration of gas sample, e.g., automotive exhaust gas, the sensor comprises a sensor base, capable of producing a output signal representative of the exothermic effect of the hydrocarbon species in the gas sample. The sensor base has disposed on, and integral with, its surface, a porous selective oxidation catalyst layer comprising capable of selectively oxidizing a combination of CO+H2+alkene species in the gas sample and leaving unoxidized the alkane and aromatic hydrocarbons. The sensor base further includes a first supported resistance temperature device which has disposed thereon a total oxidation catalyst layer capable of oxidizing the remaining alkane and aromatic hydrocarbon species in the gas sample, and a non-catalyzed second resistance temperature device.

Abstract: A method of firing ceramic materials involving placing the ceramic material in a microwave heating apparatus having a microwave cavity and subjecting the ceramic material to combination of microwave radiation and conventional heat energy according to predetermined time-temperature profile. The time-temperature profile, ranging from room temperature the sintering soak temperature, comprises a series of target heating rate temperature setpoints and a series of corresponding core and surface temperature setpoints with each of the core and surface temperature setpoints being offset from the target heating rate setpoints a predetermined offset temperature. The method involves continuously measuring the ceramic body core temperature, TC, and the surface temperature TS. Controlling of the microwave power involves adjusting the microwave power in response to a difference between core temperature setpoint and a biased core measured temperature.

Abstract: A method of firing ceramic materials involving placing the ceramic material in a microwave heating apparatus having a microwave cavity and subjecting the ceramic material to combination of microwave radiation and conventional heat energy according to predetermined time-temperature profile. The time-temperature profile, ranging from room temperature the sintering soak temperature, comprises a series of target heating rate temperature setpoints and a series of corresponding core and surface temperature setpoints with each of the core and surface temperature setpoints being offset from the target heating rate setpoints a predetermined offset temperature. In a preferred embodiment, the method involves continuously measuring the ceramic body core temperature, TC, and the surface temperature TS and independently controlling the microwave power and the conventional heat in response to the core temperature value and the surface temperature value, respectively.

Abstract: A binder system for use in the formation of ceramic or other powder-formed greenware comprising a binder, a solvent for the binder, a surfactant, and a component that is non-solvent with respect to the binder and solvent. The non-solvent component exhibits a lower viscosity than the solvent when containing the binder and comprises at least a portion of an organic liquid having a 90% recovered distillation temperature of no greater than about 225° C. and more preferably less than 220° C. Also disclosed is a process of forming and shaping plasticized powder mixtures and a process for forming ceramic articles utilizing the binder system.

Abstract: The invention relates to a method of firing a green ceramic honeycomb structural body containing an organic or carbonaceous material which is characterized by removing at least a portion of the carbonaceous material released prior to reacting within the firing atmosphere during the initial firing of the green honeycomb structural body. The invention also relates to a tunnel kiln, which includes a vestibule region, a carbonaceous material release region, having a plurality of removal zones, located downstream of the vestibule region and a sintering region located downstream of the carbonaceous material release region. The tunnel kiln further includes an exhaust removal system which operatively communicates, via offtake openings located in each removal zone, with the release region for removing released carbonaceous material.

Abstract: The invention is directed at a method of manufacturing these catalytic converters having non-round honeycomb substrates and comprises the following steps: (1) wrapping a non-round monolithic ceramic substrate, having a major and minor orthogonal axis, in a sufficient amount of the supporting mat material whereby the substrate's peripheral surface is substantially covered; (2) inserting the wrapped substrate into a metal shell, having a plurality of nodal points, which substantially surrounds the wrapped substrate; (3) placing the metal shell in a resizing die having a plurality of fingers, and associated gaps therebetween, extending axially along substantially the entire surface of the metal shell whereby the nodal points of the metal shell are positioned along a portion of a die finger and the placement of the metal shell and wrapped substrate, within the resizing die is such that the axes of the resizing die are angularly offset from the major and minor axes of the substrate; (4) compressively closing

Abstract: The present invention is directed at sintered ceramic articles exhibiting a crystalline phase assemblage comprising, by weight, of 65-95% cordierite and 5-35% of a secondary phase selected from the group consisting of mullite, magnesium-aluminate spinel, and sapphirine and having a bulk analytical composition consisting essentially of about, by weight, 32-51% SiO2, 35-49% Al2O3, 7-16% MgO. Furthermore, the ceramic articles exhibit an effective strength of greater than about 3000, a CTE of less than about 15×10−7/° C., over the temperature range of 25° C., to 1000° C., and a total intrusion porosity, as measured by a Hg intrusion method, of at least 20%. This invention also relates to a method for producing a sintered ceramic article having the aforementioned cordierite and secondary minor phase mixture.

Abstract: A plasticizable raw material mixture for use in preparing a substrate having cordierite as its primary phase with the mixture comprised of a chemical composition, percent by weight, of 11 to 17% MgO, 33 to 41% Al2O3 and, 46 to 53% SiO2. The raw material mixture specifically comprises the following: (1) one source of Al2O3 and SiO2 comprising a clay mixture having less than about 22%, by weight based on the total raw materials in the plasticizable mixture, of calcined clay; (2) an alumina yielding precursor comprising alumina having an average particle diameter of about 1 &mgr;m or less; and, (3) at least one source of magnesia having an average particle diameter of between about 3 to 15 microns.

Abstract: A catalytic converter for purifying exhaust gases from an internal combustion engine includes a monolithic ceramic substrate having a peripheral surface encircled by a non-intumescent supporting mat material. A metal shell comprising a wider portion which is adjacent to and encloses the mat material and the substrate. The metal shell further comprises a narrower portion, preferably triangularly shaped, that overlaps and is attached to the outer surface of the wider metal shell portion. The wider and narrower metal shell portions combine to exert a compressive force on the wrapped substrate.

Abstract: A method of firing a green cordierite-ceramic honeycomb structural body containing a carbonaceous material, for example, an organic binder, including a two phase process. The first phase includes firing the green honeycomb structural body to a temperature and for a time sufficient to initiate and sufficiently achieve release of the carbonaceous material while introducing into the furnace a CO2-enriched atmosphere. Once the carbonaceous material is sufficiently removed, the second phase involves further conventionally firing for a time and a temperature sufficient to initiate and sufficiently achieve the conversion of the green ceramic honeycomb structural body into a fired honeycomb body.

Abstract: Disclosed is sintered ceramic article that exhibits a primary crystalline phase of cordierite and analytical oxide composition, in weight percent, of 49-53% SiO2, 33-38% Al2O3, 12-16% MgO and exhibits a coefficient of thermal expansion no greater than about 4.0×10−7/° C. over the temperature range of about 25° C. to about 800° C. and a transverse-I ratio of not less than about 0.92. Also disclosed is a method for producing a sintered cordierite ceramic article involving preparing a plasticizable raw material, comprising a magnesium source, a SiO2-forming source and an additional component of either: (a) a clay-free, Al2O3-forming source having a surface area of greater than about 5 m2/g; or, (b) a clay and Al2O3-forming source combination wherein the clay comprises no greater than about 30%, by weight, of the total inorganic mixture, and the Al2O3-forming source exhibits a surface area of greater than about 40 m2/g.

Abstract: The invention is directed at apparatus for microwave heating of a ceramic, comprising an adjustable power microwave source for directing microwave power into a continuous throughput microwave cavity. The apparatus further includes a microwave power control system for variably controlling the power of that is delivered to the microwave cavity. The first component of this system comprises a reflected power detector for detecting the microwave power reflected from the ceramic material in the cavity. The reflected power detector measures the value of the reflected power from the cavity and compares that reflected power output value to a preset reflected output value to generate an output signal indicative of the difference in measured and set reflected values.

Abstract: Porous sintered ceramic materials having mullite as its primary phase and a method for producing them. The method includes preparing a plasticizable raw material mixture comprised, by weight, of 75-99% of the mullite powder and 1.0 to 25% of the water swelling clay and 5-25% of the alumina and/or alumina-yielding precursor, adding an organic binder system to the mixture and mixing the mixture to form an extrudable mixture, and extruding the mixture to form a substrate of the desired configuration. The green body is dried and fired for a time and at temperature sufficient to form a sintered mullite structure having an acid/base exposure strength loss of less than about 20%.

Abstract: A binder system for use in the formation of ceramic or other powder-formed greenware including a binder, a solvent for the binder, a surfactant, and a component that is non-solvent with respect to the binder and solvent. The non-solvent component exhibits a lower viscosity than the solvent when containing the binder and includes a low molecular weight oil having a 90% recovered distillation temperature range of between about 220 to 400° C. Also disclosed is a process of forming and shaping plasticized powder mixtures and a process for forming ceramic articles utilizing the binder system.

Abstract: A system for measuring the non-methane HC concentration of gas sample, e.g., automotive exhaust gas, comprises a sensor catalyst capable of selectively oxidizing the combination of CO+H2+alkene hydrocarbons in a gas sample and a catalytic differential calorimetric sensor downstream of the sensor catalyst, capable of producing an output signal representative of the exothermic effect of oxidation of the remaining aromatic and alkane hydrocarbons in the gas sample. The system also includes a heater for maintaining both the sensor catalyst and the catalytic calorimetric sensor at a temperature sufficient to achieve substantially complete oxidation of the CO+H2+alkene hydrocarbon combination and the aromatic and alkane hydrocarbons, respectively. Lastly, the system includes a means for analyzing the output signal representative of the concentration of unburned aromatic and alkane hydrocarbons in the exhaust gas to determine concentration of the total non-methane hydrocarbon species.

Abstract: Porous sintered ceramic materials having mullite as its primary phase and a method for producing them. The method includes preparing a plasticizable raw material mixture comprised, by weight, of 75 to 99% pre-reacted mullite powder, and 1.0 to 25% of a water-swelling clay, adding an organic binder system to the mixture and mixing the mixture to form an extrudable mixture, and extruding the mixture to form a substrate of the desired configuration. The green body is dried and fired for a time and at temperature sufficient to form a sintered mullite structure having a narrow through-pore size distribution comprised of pores exhibiting an average intrusion-pore size of between about 2-15 &mgr;m, and a total intrusion porosity, as measured by Hg intrusion method, of at least 30%.

Abstract: A binder system for use in the formation of ceramic or other powder-formed greenware which includes a binder, a solvent for the binder, a surfactant, and a component that is non-solvent with respect to the binder and solvent. The non-solvent component exhibits a lower viscosity than the solvent when containing the binder and includes at least a portion of an organic liquid having a 90% recovered distillation temperature of no greater than about 225.degree. C. and more preferably less than 220.degree. C. Also disclosed is a process of forming and shaping plasticized powder mixtures and a process for forming ceramic articles utilizing the binder system.

Abstract: A sensor for selectively detecting HC classes, e.g., alkanes, alkenes and aromatics, in a gas mixture comprising a metal oxide seiniconductor catalyst which is catalytically active for the selective HC classes; the reactions selected from the group consisting of partial oxidation, oxidative dehydrogenation, oxidative coupling and isomerization. Each of these reactions results in imparting a change in the electrical conductivity of the metal oxide which is proportional to the concentration of the HC in the gas mixture. Suitable metal oxide catalysts include Bi.sub.2 O.sub.3 --MoO.sub.3, CoO--MoO.sub.3, SnO.sub.2 --MoO.sub.3, TeO.sub.2 --MoO.sub.3, Sb.sub.2 O.sub.5 --V.sub.2 O.sub.5 --MoO.sub.3, SnO.sub.2 --Sb.sub.2 O.sub.5, Nb.sub.2 O--V.sub.2 O.sub.5 --MoO.sub.3, V.sub.2 O.sub.5 --MoO.sub.3, ZnO--Fe.sub.2 O.sub.3, Li.sub.2 O--MgO, V.sub.2 O.sub.5 --P.sub.2 O.sub.5, metal oxide compounds of a spinel or perovskite crystalline structure, and mixtures thereof.

Abstract: A method of manufacturing a catalytic converter for purifying exhaust gases from an internal combustion engine wherein the converter exhibits a monolithic ceramic substrate surrounded by a supporting mat. The method includes the steps of: wrapping the substrate in a sufficient amount of supporting mat material and inserting the wrapped substrate into the metal shell; forming a cylindrical metal shell having an inner surface exhibiting substantially the same curvature as the wrapped substrate; compressively closing the metal shell around the wrapped substrate to an optimized mat density range thereby resulting in the supporting mat exhibiting a substantially uniform and maximum safe compressive stress on the substrate; and, securing together metal shell to provide a gas tight seal and to hold the compressive stress.