Abstract: Apparatus for injecting gas into molten metal includes a porous ceramic body having a first surface through which gas can be introduced into the body, and a second surface through which gas can flow from the body. A refractory member is attached to the body and surrounds at least the first surface, while leaving the second surface exposed. The refractory member is impervious to gas, while having a coefficient of thermal expansion approximating that of the body. Preferably, a refractory sealant securely attaches the refractory member to the body. By use of the present invention, the refractory member and the body remain tightly connected to each other at all times. Accordingly, gas leaks are prevented and all gas flowing into the body is discharged through the second surface, as desired.

Abstract: Provided is a composite for use as thermal insulation in high temperature environments. The composite comprises a layer of randomly laid and oriented, fine diameter, heat resistant fibers interlocked together into the form of a shape sustaining paper having a high fiber index and two lateral surfaces, said paper being compressed to produce a paper which has a thickness of from about 0.01 to 0.50 inch and a density of about 6 to about 30 lb/cu.ft. A high temperature resistant scrim is disposed upon each of the lateral surfaces of the paper, and a network of abrasion-resistant, high temperature-resistant threads is stitched through the scrim and the paper such that the scrim is mechanically locked to the paper by said threads. The network of threads and the scrim substantially retain the structural integrity of the said paper to maintain said paper in compression.

Abstract: A molten metal pump includes a filter that prevents ingestion of foreign material such as dross from molten metal within which the pump is immersed. The filter is a large structure that is secured to the base of the pump surrounding the pump's inlet. The filter forms a cavity adjacent the pump's inlet. The ratio of the surface area of the filter to the inlet area of the pump is very large; the filter has a low porosity while maintaining a high flow rate for the pump.

Abstract: A method for grinding an oxygen sensitive ceramic material to a powder which comprises grinding an oxygen sensitive ceramic feed material having an average particle size of between 1 and 200 microns in a contamination free high energy autogenous attrition mill in non-oxidizing fluid in the presence of media for a sufficient time to obtain a specific surface area of at least 5 m.sup.2 /g and preferably at least 9 m.sup.2 /g. The media consists essentially of the same ceramic as the feed material is of high purity and has an average particle size of less than 4 mm and preferably less than 2.5 mm. the ground material may be further treated so that the average particle size is less than one micron and so that the greater than 97 numerical percent of the particles of the finished powder is smaller than 5 microns. The invention includes the finished powder.

Abstract: An impeller assembly is disclosed which is arranged to produce linear flow of fluid which prohibits radial flow of that fluid. An impeller is surrounded by a hollow cylindrical section mounted and fixed to the periphery of the impeller blades. The cylindrical section may extend either beyond the leading edges of the impeller blades or beyond the trailing edges of the impeller blades, or both, along the axis of rotation of the impeller assembly.

Abstract: An anode for plasma torch that has a primary section and a secondary section with a gradual transition between the sections. The diameter of the hollow primary section tapers down toward a transition zone, at which point the anode formed by the sections makes a gradual transition to the secondary section. The secondary section is cylindrical and has a diameter larger than that of the primary section from which the plasma exists the anode. The transition zone will describe a generally conical surface and may include a convex radius on the neck where the primary and transition sections meet.

Abstract: There is disclosed a radiation vault enclosure comprising a radiation resistant structure, means for a web of material to enter said structure, means to carry said web past a source of electron beam radiation in said structure, means for said web to leave said structure and access means for a person to enter said radiation resistant structure for cleaning of the said means to carry said web. In a preferred embodiment the path of a curable resin coated web material through the chamber may be adjusted to provide electron radiation either to the wet resin side of the web or the back side of the web to cure the resin.

Abstract: A method for increasing the boron.sup.10 content of a neutron absorbing article, such as one in flat, flexible sheet shape, includes coating a surface of such article with a solidifiable liquid synthetic organic polymeric material, such as a phenol formaldehyde type resin, applying boron carbide particles to the polymeric material and solidifying the polymer, such as by curing to cross-linked permanently set form, so as to hold the neutron absorbing boron carbide particles in place thereon. In highly preferred embodiments of the invention the boron carbide particles applied will extend beyond the surface of the external material and will serve as anchoring means for applications of subsequent coatings and the plurality of coatings, usually after initial partial curing to solidify them and make them form-retaining, will be permanently cross-linked simultaneously.

Abstract: A cask for radioactive material, such as nuclear reactor fuel or spent nuclear reactor fuel, includes a plurality of associated walled internal compartments for containing such radioactive material, with neutron absorbing material present to absorb neutrons emitted by the radioactive material, and a plurality of thermally conductive members, such as longitudinal copper or aluminum castings, about the compartment and in thermal contact with the compartment walls and with other such thermally conductive members and having thermal contact surfaces between such members extending, preferably radially, from the compartment walls to external surfaces of the thermally conductive members, which surfaces are preferably in the form of a cylinder. The ends of the shipping cask also preferably include a neutron absorber and a conductive metal covering to dissipate heat released by decay of the radioactive material.

Abstract: A biaxially heat shrinkable sleeve, a prism which is usually a roller having its lateral area covered with a biaxially heat shrunken sleeve and the method for covering the lateral area of a prism such as a process roller with a biaxially heat shrunken sleeve.

Abstract: A refractory moldable composition which, upon drying, sets up to refractory shapes which are strongly adherent to the molding surfaces and are essentially crack-free, contains about 45 to about 65% of a liquid vehicle, such as water; about 21 to about 26% ceramic fiber; about 7 to about 30% finely divided silica; and sufficient adhesion enhancing agent to impart from about 18 to about 50 grams per square centimeter adherence to steel. The molded composition adheres excellently to molding surfaces and dries to give an essentially crack-free refractory shape, useful as thermal insulation at temperatures up to 1300.degree. C. The composition may optionally include hollow plastic or ceramic spheres.

Abstract: An improved throw-away, or single use, adaptor particularly useful with depressed center grinding wheels is described. The adaptor comprises a hollow mandrel having an internal threaded portion for attaching the adaptor to the shaft of a grinding machine. The hollow mandrel has a saucer-shaped disc portion extending axially from the outer portion of the mandrel. The saucer-shaped disc portion has a concave surface and a convex surface. The concave portion is equipped with a plurality of internal rib members and has a flange around the periphery thereof to contact the side of a grinding wheel. The flange portion has a plurality of protrusions, or bosses, thereon adapted to be received in corresponding orifices in the grinding wheel. In operation, as the grinding wheel contacts a work piece, the torque, or stress, is directly imparted to the adaptor, as the adaptor is threadably attached to the shaft of the grinding wheel.

Abstract: A shrink resistant flexible ceramic fiber and its process of manufacture which comprises melting from about 40 to 65 weight percent of alumina with from about 35 to about 60 weight percent of silica, forming fibers from the melt, rapidly solidifying the fibers, heating the fibers to a sufficient temperature for a sufficient time to form microcrystals and cooling the fibers to below the crystallization temperature before macrocrystals can form.

Abstract: A process for strengthening carbide fibers by removing internal stresses caused by their formation. This process is accomplished by drawing the carbide fiber under tension through a furnace. The temperature of the furnace may range from about 2050.degree. to 2300.degree. C. while the fiber tensile stress may vary from about 200 to 3500 p.s.i. when using boron carbide fibers with diameters ranging from about 8 to 14 microns.

Abstract: A method of pressureless sintering silicon carbide mixtures to obtain a sintered, dense product when the silicon carbide starting materials do not include a densification aid, such as boron, beryllium or aluminum, is described. The starting materials are mixtures containing predominantly particulate silicon carbide and include usually less than about 10 and, preferably, less than about 6 percent by weight of carbon in the form of elemental carbon or in the form of a carbon source material. The mixtures may also contain minor amounts of other additives, such as lubricants, surfactants or agglutinants, to aid in forming a compact, or green body, from the mixtures, or minor amounts of other ceramic materials depending upon the nature of the desired final product. The mixtures are formed into compacts, or green bodies, by known techniques.

Abstract: An apparatus for fuel ignition comprising an electrical source for providing electrical current; an electrically operated fuel ignition means; a valve means which allows passage of fuel to the ignition means when the valve means is opened; a first valve control means which will open the valve upon application of an electrical current and a second valve control means which will retain the valve means in an open position but will not initially open the valve upon application of an electrical current; an activating switch electrically connected between the electrical source and the rest of the apparatus so that the apparatus will not operate unless the activating switch is closed; a time delay switch connected between the activating switch and the rest of the apparatus and connected to an ignition sensing switch means so that the time delay switch stops the flow of electrical current to the rest of the apparatus if the ignition sensing switch means does not sense ignition within the time delay; and an ignition s

Abstract: Ceramic compositions that may be injection molded and subsequently sintered are described. A particulate ceramic material, such as silicon carbide, is coated with a mixture of thermoplastic resin and oils or waxes, and utilized as a feed material in an injection molding process. The molded product may subsequently be sintered at 2000.degree. C. to 2200.degree. C. to produce a hard, dense article.

Abstract: A composition comprising negatively doped hot pressed particulate silicon carbide, the process for making the composition, an electrical hot surface fuel ignitor manufactured from the composition, a silicon brazed electrical connection for the ignitor and an ignitor circuit containing a dropping resistance.

Abstract: A neutron absorbing article, preferably in long, thin, flat form, suitable for but not necessarily limited to use in storage racks for spent nuclear fuel at locations between volumes of such stored fuel, to absorb neutrons from said spent fuel and prevent uncontrolled nuclear reaction of the spent fuel material, is composed of finely divided boron carbide particles and a solid, irreversibly cured phenolic polymer, forming a continuous matrix about the boron carbide particles, in such proportions that at least 6% of B.sup.10 from the boron carbide content is present therein.

Abstract: A coated abrasive belt backing material woven from 100% high tenacity polyester staple yarns in a sateen weave is heat set and destretched to a dimensional stability warpwise of less than 6.5% elongation at 170 pounds per linear inch of width tensile, while maintaining its desired width during such heat setting and destretching, cloth finished, coated with maker, abrasive and size, cured and product finished to form endless belts having superior properties of strength, toughness, body retention, pliability and base adhesion.