Abstract: An oven, is provided that includes multiple heat transfer means, including convection and microwave heat transfer means. The oven includes a cooking chamber, a blower and at least a shelf disposed within the cooking chamber. The shelf is designed to act as a food support as well as a conduit through which heated air passes into the cooking chamber. The microwave heating means comprises a microwave source and wave guide through which microwaves travel. The wave guide includes a plurality of openings through which microwaves can pass into said cooking chamber. In the preferred embodiment, the openings in the wave guide are positioned to correspond with the predetermined minima or maxima for the microwave wavelength propagating within the wave guide. An electric heating element may also be disposed within the cooking chamber to provide an alternative heating source.

Abstract: A process for pressure molding an article around a hardened salt mold core made from a mixture of relatively low melting temperature salt and sand wherein the core is removed from the finished article by immersion of the article containing the core into a molten bath mixture of the core material thereby to melt the core out of the article, recover the core material, and thus replenish the bath for use in making additional cores. The bath is originally constituted by melting a suitable quantity of a dry premix of the salt and sand.

Abstract: A bath for treating a metallic workpiece so as to provide a surface finish thereupon includes a reagent adapted to react with the surface and an abrasive material. Relative agitational motion between the abrasive and the workpiece is provided and in this manner the abrasive promotes uniform reaction of the workpiece surface with the reagent so as to provide a uniform, deposit-free coating. Also within the scope of the present invention is a method for treating workpiece surfaces utilizing such a bath.

Abstract: Casting cores are fabricated from a mixture comprising a molten salt having dispersed therein a particulate material which includes a first refractory material having a mesh size of 60-120 and a second refractory material having a mesh size of at least 200. The salts are preferably halides, carbonates, sulfates, sulfites, nitrates or nitrites of Group Ia and Group IIa metals and the refractory material may be selected so as to be non-reactive with the molten salt. Some preferred refractory materials include alumina and magnesium silicate.

Abstract: A method of quenching metal components utilizing a water based quenching composition which includes a polyvinylpyrrolidone polymer of high molecular weight and in relatively high concentrations and thereafter power washing the parts to remove the polymeric film. Another preferred embodiment uses the same high molecular weight polyvinylpyrrolidone in combination with two rust inhibiting agents which greatly extend the time during which the quenchant film left on the quenched parts remains water soluble, while still providing an excellent approximation of the cooling curve characteristic of an oil quenchant.

Abstract: Impingement heating or cooling apparatus that employs an axial flow fan, a plenum, collector and a columnating assembly for directing jets of a temperature controlled gas against the surface of a food product. Means for contacting a first layer of food products with impinging jets of a temperature controlled gas and for simultaneously contacting a second layer of food products with an alternating, convective flow of a temperature controlled gas is also provided.

Abstract: A method of quenching metal components utilizing a water based quenching composition which includes a polyvinylpyrrolidone polymer of high molecular weight and in relatively high concentrations and thereafter power washing the parts to remove the polymeric film. Another preferred embodiment uses the same high molecular weight polyvinylpyrrolidone in combination with two rust inhibiting agents which greatly extend the time during which the quenchant film left on the quenched parts remains water soluable, while still providing an excellent approximation of the cooling curve characteristic of an oil quenchant.

Abstract: A method of solution heat treating aluminum alloys, especially aluminum-lithium alloys, by immersing the alloy article in a chloride based neutral salt bath rather than in the conventionally used nitrate based salt bath. A chloride based bath, at least in certain controlled situations, produces an effective solution heat treatment but without the staining and corrosive reaction often encountered with the nitrate based salt baths. A chloride based salt comprising 55% potassium chloride, 40% lithium chloride, and 5% sodium chloride is found to be particularly effective.

Abstract: Aqueous compositions for the treatment of barium-toxic waste waters are provided. The compositions, which are storage stable at freezing temperatures, include ammonium sulfate and an agent for in situ coagulation of non-ionic barium in the form of environmentally safe solid phase particulates.

Abstract: A method is provided for the recovery and recycle of nitrate and nitrite salts present in environmentally hazardous chloride containing quench bath solids, comprising the steps of leaching the solids with hot water to provide an aqueous leachate that depletes the hot water soluble content of the solids, clearing the resulting aqueous leachate of solids, and recycling it while hot into a fused quench bath.

Abstract: The subject invention provides a method and apparatus for the control and or rectification of molecular weight distribution of polymeric quenchants. In general this is accomplished by selective filtration and elimination of lower molecular weight constituents and the resulting restoration of the molecular weight balance which is necessary to maintain the quench of the desired severity.

Abstract: A system for recycling heat treating salts such as nitrates and nitrites from a rinse bath including means to prevent the excessive build-up of impurities such as carbonates or chlorides which impair heat treat efficiency. For example, carbonates which form in a nitrate-nitrite quench bath and chlorides which are carried by drag-out into a nitrate-nitrite quench bath from a chloride heat treating bath are removed by concentrating the rinse water, removing undesirable components from the concentrate and returning molten rectified salt to the quench.

Abstract: A cyanide-free molten salt carburizing process and composition comprising an alkali metal salt bath having a cover of finely divided graphite particles in a size range of about 100 mesh to about 300 mesh. The bath is operated in the temperature range of about 1550.degree. F. to 1900.degree. F. and is provided with mechanical agitation to produce entrainment of air through the surface cover and sufficient mobility of carbon monoxide coated graphite particles to produce carbon diffusion by contact into the surface of the parts immersed in the bath. Total graphite content is between about 11/2% to about 7% of the active portion of the bath. The graphite is preferably of the synthetic type so as to produce an ash content below about 1%.

Abstract: A system for recycling heat treating salts such as nitrates and nitrites from a rinse bath including means to prevent the excessive build-up of impurities such as carbonates which impair heat treat efficiency. For example, carbonates which form in a nitrate-nitrite quench bath are removed by concentrating the rinse water, rectifying the concentrate and returning molten rectified salt to the quench.

Abstract: Addition of special thermally decomposable chloro compounds intimately mixed and pelleted or briquetted with a neutral binder material is made to molten neutral salt baths to restore neutrality by converting oxides of the alkali/alkaline earth metals back to chlorides and dispelling the remainder of the compound as a vapor.

Abstract: Paint-coated objects are immersed in a molten salt bath to remove paint therefrom. The bath contains in weight percent: a) about 25-90% of alkali or alkaline earth caustic compounds; b) about 2-10% of an oxidizing agent selected from the group consisting of alkali and alkaline earth metal nitrates, nitrites, molybdates, metasilicates, and vanadates; c) about 5-40% of a surface scum reducing agent selected from the group consistng of alkali and alkaline earth metal sulfates and pyrophosphates; d) 0-60% of diluent salt selected from the group consisting of chloride, carbonate, and fluoride salts.

Abstract: A method of quenching metal components utilizing a water based quenching composition which includes a polyvinylpyrrolidone polymer of high molecular weight and in relatively high concentrations and thereafter power washing the parts to remove the polymeric film. Another preferred embodiment uses the same high molecular weight polyvinylpyrrolidone in combination with two rust inhibiting agents which greatly extend the time during which the quenchant film left on the quenched parts remains water soluable, while still providing an excellent approximation of the cooling curve characteristic of an oil quenchant.