Abstract: Disclosed herein is an improved wood burning stove having a combustion chamber and a flue for removing exhaust from the chamber wherein the improvement comprises the addition of a catalytic converter means for oxidizing oxidizable species in the exhaust. In one embodiment, the catalytic converter means is situated in a flue immediately adjacent the combustion chamber. In another embodiment, the catalytic converter means is situated in the combustion chamber itself. In addition, the nature and structure of a catalytic converter means have been determined for marginal acceptable and optimum performance with adequate pressure drop thereacross.

Abstract: Elimination of shearing flow, having an inwardly radial flow and velocity gradient, of extrudable material entering a die for forming a honeycomb structure with a plurality of thin-walled cells, thereby avoiding irregularities in the extruded structure. The shearing flow, resulting from reducing cross-sectional area of a Bingham plastic material (e.g. a cordierite-forming, plastically moldable ceramic batch material) passing through a funnel section tapering inwardly from an extrusion barrel, is changed to plug flow by maintaining constant the reduced cross-sectional area through a straight-walled portion of an entrance cavity feeding the material to the die, which has passageways including a plurality of feed holes communicating with interconnected discharge slots sequentially in the extrusion detection for forming the honeycomb structure.

Abstract: Thermally collapsible core of three to five solid carbonaceous segments of generally equal volume and of wedge-like shape arranged around a collapse axis of the core in narrowly spaced apart relation to each other. Core includes spacers occupying a minor portion of the narrow spacing nearest the external periphery of the core and which are made of metal, glass, ceramic or mixtures thereof having a melting point below the highest temperature to which the core is subjected by molten material solidifying therearound, e.g. fusion-cast refractory. The segments are the larger parts of the core. Heat transferred from solidified molten material to core causes spacers to melt and allow segments to collapse inwardly toward collapse axis to accommodate cooling shrinkage of casting without cracking. Melted spacers can drain downwardly out of core. Design yields highly quenched microstructure in fusion-cast refractory, which is especially beneficial in tap hole blocks for steelmaking furnaces and vessels.

Abstract: Oxygen sensor comprising solid oxygen-ion-conducting electrolyte with a platinum group metal film electrode contacts and monitors nonoxidizing or reducing gas atmosphere in a metal heat treatment (gas carburizing) furnace after a getter of the same platinum group metal as in the film electrode removes platinum group metal contaminants from such atmosphere before it contacts the electrode. Getter is held in a thin-walled, multi-passaged honeycomb body.

Abstract: Disclosed herein is an improved wood burning stove employing a combustion chamber and a flue in communication therewith for removal of exhaust from the chamber with a catalytic converter means being movably mounted in the flue whereby the impedance presented to the exhaust by the converter may be selectively varied so as to minimize the impedance presented by the converter means when additional fuel is added to the stove.

Abstract: A method of improving the thermal shock resistance of a honeycombed structure through which fluids flow and formed by joining a plurality of cellular segments to one another along their peripheral walls, by providing discontinuities through the joints formed between the adjoining segments in the direction of the fluid flow through the structure so as to lessen temperature differences occurring in the joint area, to provide the structure with greater flexibility and to act as crack arrestors lessening the transmission of stresses between adjoining segments and through the joints. In two preferred embodiments, the invention is practiced in forming a heat recovery wheel by joining a plurality of cellular segments to one another with cement which is striped to the segments so as to form a plurality of hollow, straight walled, channels extending essentially axially through some or all of the joint areas of the resulting wheel.

Abstract: Disclosed is a novel extrusion die mask for use in the extrusion of honeycomb structures. The mask includes a stationary portion with an orifice extending longitudinally therethrough. A movable recess means is provided which forms a recess communicating between the outlet face of an extrusion die and the central orifice which receives and compacts extruded batch material from the die to form the skin of the extruded honeycomb structure. An adjustment means is provided for controlling the depth of the recess whereby the amount of material directed to the skin of the structure may be varied as batch viscosity varies and as product requirements indicate.

Abstract: The thermal shock resistance of a honeycombed structure or a structure having a honeycombed surface formed by bonding together a plurality of cellular segments each having a honeycombed face forming a portion of the structure or surface of the structure, respectively, is improved by recessing the bond joints between the joined cellular segments from the surface. The thermal shock resistance of a heat recovery wheel operated in a counterflow heat exchanger system and formed from joined cellular segments is improved by recessing the bond joints joining the cellular segments, preferably approximately one-half inch (12.7 mm), from the face of the wheel exposed to the gases at their highest temperatures.

Abstract: Disclosed is a novel mounting structure for a rotatable heat exchanger, sometimes known as a heat recovery wheel. The mounting structure includes a hub portion on at least one side of the wheel and axially aligned therewith with at least three radially movable shoes situated within the bore of the wheel and coupled to the hub portion. A torsion bar is connected to the hub which applies equal radial forces to each of the shoes whereby the shoes are biased against the wheel at the periphery of the bore and equally displaced from the axis of the wheel. The aforementioned arrangement provides a mounting which is self centering and yet which permits differential radial expansion of a metal hub with respect to a ceramic wheel.

Abstract: An improved seal column design for use in counterflow heat exchanger systems having a centrally supported rotary heat exchanger or heat recovery wheel having an integral strengthened central hub. According to the invention, the edges formed between the end wall of each seal column juxtaposed an annular face of the wheel and the side walls of the column exposed to and separating the fluid flows are straight and parallel to one another and evenly spaced, at their point of closest approach, between one-half inch (1.27 cm) and one and one-half inches (3.81 cm) and preferably one inch (2.54 cm) beyond the outer circumference of the hub. Also, the side walls of the columns are straight and parallel to one another in the vicinity of the end wall.

Abstract: Disclosed herein is an improved wood burning stove employing a combustion chamber and a flue for removing exhaust therefrom and also a catalytic converter means for oxidizing oxidizable species in the exhaust. A passageway is provided for bypassing the exhaust around the catalytic converter means, the passageway being controlled by a bypass damper for controlling access to the passageway for varying impedance otherwise presented to the exhaust by the converter, for example, during the addition of fuel to the stove. Such an arrangement minimizes back pressure caused by the converter means.

Abstract: Disclosed is an improved ceramic heat recovery wheel driven on a shaft containing a metal hub which may be driven without slippage between the wheel and the hub. The wheel includes a splined metal shaft which mates with the disk including a plurality of radially extending keys equi-angularly spaced about its circumference. The ceramic disk includes an equal plurality of radially extending keyways which mate with the keys. In one embodiment, the keys are situated on only one side of the bore of the ceramic disk and the keyways do not extend through the bore. On the opposite face of the disk, a retainer plate surrounds the shaft. An axial force is applied to the retainer plate for restraining movement of the wheel in the axial direction.

Abstract: Apparatus for filtering solid particulates from suspension in fluid streams (especially carbon particulates from exhaust gas of diesel engines) comprising a honeycomb filter with thin porous walls defining cells extending therethrough, with the transverse cross-sectional shapes of the cells forming a repeating pattern of geometric shapes without interior corner angles of less than 30.degree. and with alternate cells forming an inlet group and an outlet group. The inlet group is open at the inlet face and closed adjacent the outlet face. The outlet group is closed adjacent the inlet face and open at the outlet face. Each cell of each group shares cell walls only with cells of the other group. The walls have a volume of substantially uniform interconnected open porosity and a mean pore diameter of the pores forming the open porosity lying within the area defined by the boundary lines connecting points 1-2-3-4 in FIG. 4.

Abstract: Disclosed is a mounting device for a ceramic heat recovery wheel having a central bore therein. A metal hub is situated in the bore having a plurality of radially movable shoes for fastening the hub to the wheel. The radially movable shoes each have a radially directed stem with a contact portion abutting the ceramic wheel. The contact portion has a substantially greater cross-sectional area than the stem and in the preferred embodiment is a double cantilevered beam extending from the stem. The cantilevered beams are permitted to bow or flex when subjected to extreme temperatures, thereby permitting radial displacement of the shoe without subjection of the ceramic disk to extreme tensile forces which might cause its breakage.

Abstract: Disclosed is an extrusion die for use in forming extruded honeycomb structures employing a face plate having a plurality of discharge slots and a back plate having a plurality of feed passageways. The face plate and the back plate are joined to one another by means of bonding, e.g. brazing, at the joint formed by abutting surfaces of the plates. Proper orientation between the face plate and the back plate are maintained during brazing such that the feed passageways and discharge slots remain properly associated by means of a plurality of alignment cavities having walls opening to and diverging toward and to the joint between the face plate and back plate.

Abstract: Disclosed is a novel rotary heat exchanger and heat exchange system for use in gas turbine engines and other environments. The heat exchanger includes a ceramic disk having a ring gear extending about the outer circumference thereof. The ring gear is joined to the ceramic disk by means of an elastomeric member. However, means are provided for keeping the elastomeric member below its degradation temperature. These means include the provision of filler material for blocking a plurality of passages at a first and second face of the disk thus forming annular bands concentric therewith on opposite faces of the disk. A plurality of passages at the periphery of the disk radially outwardly of the bands are unobstructed by the filler material such that cooling air may flow therethrough so as to keep the elastomeric material at the desired temperature.

Abstract: Impervious, unglazed, sintered ceramic products of primarily cordierite crystal phase, exhibiting low coefficients of thermal expansion and having analytical molar composition of about 1.7-2.4 RO . 1.9-2.4 Al.sub.2 O.sub.3 . 4.5-5.2 SiO.sub.2, are formed of mineral batch compositions that are: (a) wholly raw ceramic material wherein RO comprises about 55-95 mole % MnO and 5-45% MgO, or (b) at least about 50 wt.% prereacted cordierite material and the balance thereof raw ceramic material, and wherein RO comprises about 5-40 mole % MnO and 60-95 mole % MgO.

Abstract: Ceramic material, and cryogenic refrigeration apparatus containing thermal energy absorbing elements made of the ceramic material, which is a dielectric insulator and has values of specific heat at selected temperatures below 15.degree. K. that are greater than or at least equal to the values of specific heat of pure lead at those same temperatures. Material consists essentially of a crystalline phase with a composition defined by the molar formula selected from: (1) AB.sub.2 O.sub.4 where A is Group 2b metal ions with or without other divalent metal ions and B is Cr ion with or without other trivalent metal ions, (2) AB.sub.2 O.sub.6 where A is Mn and/or Ni ion(s) with or without other divalent metal ions and B is Nb and/or Ta ion(s), and (3) A.sub.2 BCO.sub.6 where A is Pb ion with or without other divalent metal ions, B is Gd or Mn with or without other trivalent metal ions and C is Nb and/or Ta ion(s). Elements include regenerator packings, thermal dampers and dielectric insulation.

Abstract: Foamable particulate cement is capable of forming sintered cordierite foamed ceramic masses. It consists essentially, by weight, of 1-40% cordierite grog, 99-60% ceramic base material and foaming agent, such as SiC. The ceramic base material is raw ceramic material that has an analytical molar composition consisting essentially of about 1.7-2.4 MO . 1.2-2.4 Al.sub.2 O.sub.3 . 4.5-5.4 SiO.sub.2 wherein MO comprises about 0-55 mole % MgO and at least 45 mole % MnO. The grog is ceramic material that has been previously fired and comminuted, and that has an analytical molar composition consisting essentially of about 1.7-2.4 RO . 1.9-2.4 Al.sub.2 O.sub.3 . 4.5-5.2 SiO.sub.2 wherein RO comprises MnO in an amount of 0 mole % up to a mole % that is about 20 mole % lower than the mole % of MO that is MnO and the balance is substantially MgO.

Abstract: Ceramic material, and cryogenic refrigeration apparatus containing thermal energy absorbing elements made of the ceramic material, which is a dielectric insulator and has values of specific heat at selected temperatures below 15.degree. K. that are greater than or at least equal to the values of specific heat of pure lead at those same temperatures. Material consists essentially of a crystalline phase with a composition defined by the molar formula selected from: (1) AB.sub.2 O.sub.4 where A is Group 2b metal ions with or without other divalent metal ions and B is Cr ion with or without other trivalent metal ions, (2) AB.sub.2 O.sub.6 where A is Mn and/or Ni ion(s) with or without other divalent metal ions and B is Nb and/or Ta ion(s), and (3) A.sub.2 BCO.sub.6 where A is Pb ion with or without other divalent metal ions, B is Gd or Mn with or without other trivalent metal ions and C is Nb and/or Ta ion(s). Elements include regenerator packings, thermal dampers and dielectric insulation.