Abstract: A method and a device for drying machine parts, e.g. balls or rolls for roller bearings, upon washing the parts in a washing liquid containing a solvent, especially a polluting solvent. Upon washing, the wet parts are fed into a chamber, and a dry, hot gas is injected into the chamber and evacuated therefrom. The evacuated humid gas is recirculated in a circuit and, upon being compressed and cooled, the gas is freed from its solvent contents in a liquid separator and is heated before re-injection into the chamber. A reduced gas pressure is maintained in the chamber by controlling the gas flow in the recirculation circuit, and the gas in the chamber is cooled, so that the partial pressure of the solvent in the chamber is substantially reduced.

Abstract: A furnace for the melting and refining of raw copper and/or blister copper comprises a shaft furnace having a lock-chamber feeder for the material at the top of the shaft furnace and an opening into a hearth furnace in which the copper is refined. The shaft furnace and the hearth furnace are constructed unitarily with one another with the shaft furnace surmounting the hearth furnace in such manner that, when the apparatus has been charged, a pile of copper is formed which is supported on the bottom of the hearth furnace and slopes toward a portion of the length of the hearth furnace.

Abstract: A method and apparatus for removing combustible material from metal scrap. The apparatus includes an inclined rotating retort, and scrap metal containing combustible material is fed into one end of the retort and as the scrap moves through the retort the combustible material is burned from the scrap. The retort is spaced within an outer refractory housing to provide an annular chamber therebetween, and the chamber is divided into two or more zones. Located within each zone is a fuel burner and a cooling air inlet. The temperature is sensed in each zone, and if the temperature falls below a preset minimum, the burner in that zone is operated, while if the temperature in the zone exceeds a pre-set maximum, cooling air is supplied to that zone to thereby maintain the temperature of the scrap metal within predetermined limits.

Abstract: A columnar stream of scrap particles having about 15-25 percent full density, is electrically inductively heated in a reducing atmosphere while being laterally confined by walls which are not made so hot as to become tacky or adhere to the confined column of scrap particles. The heated stream is laterally squeezed to increase its density to about 40-50 percent full density and is pulled downwards, out of extensive confinement by such walls. It is then inductively heated in a reducing atmosphere to a higher temperature than in the prior induction heating step, and squeezed to a greater extent, sufficiently to form a fully dense layer about the whole of the outer peripheral surface of the stream. By preference, insufficient heat and/or pressure are used to condense the stream to a fully dense condition right to its core. If this stream does not continue directly into another continuous process, it is severed into a succession of billets each end of which is sealed to prevent internal oxidation of the billets.

Abstract: Gas is injected into molten metal, such as aluminum, to purify the molten metal either of dissolved gases (degassing), or of dissolved solids such as magnesium ( "demagging"). The apparatus for accomplishing this injection contains two metallic bath chambers, the molten metal being transferred from one chamber to the other through a conduit. A gas injection conduit is connected to the metal transfer conduit at a location submerged within the first metallic bath chamber from which metal is transferred to the second chamber, and the gas to be injected is introduced through this gas injection conduit into a location submerged within the first metallic bath chamber.

Abstract: This invention relates to a method of removing oil from metal scrap, comprising the steps of introducing oil-laden scrap into a hermetically sealed chamber, evacuating said chamber, heating said scrap to vaporize the oil, and removing the vaporized oil from said chamber.

Abstract: A metal batch preheating method comprises positioning an elongate mass of metal scrap on a conveyor in a tunnel furnace for heating such furnace having longitudinally spaced transversely extending zones of greater and lesser heat, the conveyor being loaded with metal for the length of the tunnel furnace except for the last heat zones therein. The metal is thereafter moved through a plurality of "advance and heat" movements in the furnace during the batch heating cycle so that the metal is exposed to both greater intensity and lesser intensity heat zones as it is preheated after which the metal is discharged for use or further processing.

Abstract: A fuel-fired furnace for melting metal in a more efficient manner, the furnace having a burner with its combustion air being preheated by passage through an air chamber between spaced inner and outer walls of the furnace jacket and by passage through a heat exchanger through which waste combustion products pass. The jacket is double insulated and the burner is cooled by a special arrangement.

Abstract: An improved system for melting metal scrap in a molten melting media includes a housing generally cylindrical in cross section and having upper and lower portions. Metal scrap is introduced to a body of molten melting media contained in the upper portion of the housing. A supply of molten melting media is added to the upper portion of the housing through a volute located in the lower portion. The molten melting media is supplied or added by action of an impeller located in the lower portion and mounted on a drive shaft extending through the upper portion. Vanes are mounted on the drive shaft to control the flow motion of the body of molten melting media and metal scrap in the upper portion of the housing by creating a vortex in this body for purposes of mixing the melting media and metal scrap. An opening is provided in the upper portion to remove melted scrap and melting media at a rate substantially commensurate with their rate of introduction.

Abstract: An improved apparatus for the filtration of molten metal for use in the production of castings is disclosed in which a ladling crucible provided with a ceramic foam filter is employed in a furnace type crucible to remove impurities.

Abstract: Scrap metal is preheated by electrical radiant heating means. Volatiles driven off from the metal are mixed with air and are blown through conduits which constitute the electrical radiant heating elements. Combustion takes place inside the conduits and the products of combustion are directed through openings in the conduits onto the scrap metal. The temperature and pressure in the system is controlled by dampers arranged at each end of the conduits to vary gas recirculation.

Abstract: A reverberatory furnace which has an external passage for recycling hot exhaust gases from the furnace chamber back to the main burner port, means for introducing additional air or oxygen into the recycling passage, and a main burner which supplies fuel plus up to 50 percent of the air or oxygen required for total combustion into the furnace chamber so that the air or oxygen added to the recycling passage is thereby preheated by the exhaust gases and mixes with the fuel-rich mixture from the burner to provide complete combustion of the exhaust gases while simultaneously reducing the cost of the fuel requirement because of the preheating effect of the exhaust gases on the additional supply of air or oxygen.

Abstract: A furnace for melting solid ferrous pieces such as pig iron and steel scrap, features a combination of electric induction heating and flame heating of the pieces which are charged into the furnace hearth via a charging stack up through which the products of combustion flow from the furnace counter-current to the descending charged pieces moving downwardly through the stack. The flame heating is via burners supplied with hydrocarbon fluid fuel with oxygen proportioned for incomplete combustion, the products of combustion and unburned fuel ascending through the stack and preheating the descending charged pieces. Air is supplied to the stack to complete the combustion of the previously unburned fuel in and around the descending pieces, this being done at a level where the descending pieces have not yet reached temperatures sufficient to cause excessive oxidation of the pieces. Other details providing for effective utilization of these principles, are included in the disclosure.

Abstract: Apparatus for feeding small pieces of metal scrap into a mold while molten metal of the same or similar analysis is being poured includes means for heating the scrap, a chute for feeding scrap to the mold and means for positively feeding the heated scrap at a controlled rate to the chute.Heated and clean scrap is thrown by a throwing machine at a controlled velocity through a closed chute into the mold. Means may be provided to change the angle of discharge of scrap into the mold. Scrap may be fed to the throwing machine from a vibratory feeder which controls the rate of feed and receives the scrap from a hopper. The vibratory feeder may be omitted and a plurality of compartments may be provided in the hopper. Individual control of flow of scrap from each compartment controls the rate of scrap feed. The velocity of the scrap is sufficient to enable it to penetrate into the molten metal.

Abstract: This invention provides a furnace system for and method of melting metal charges which utilizes hot gases generated by a burner, and are ordinarily discharged from the furnace as waste, for the dual purpose of preheating metal to be subsequently melted and preheating combustion air which is used to provide more efficient operation of the furnace burner.

Abstract: A pollution control kettle for heating tar and the like and includes a portable tank for containing liquid tar, which tank is provided with a generally vertically extending partition dividing the tank into two adjacent vats. Heaters are provided for selectively heating tar in each of the vats to different temperatures, providing a low temperature vat and a high temperature vat. The partition is provided with at least one opening therethrough which provides free fluid flow between the vats, with the opening being spaced substantially below the normal liquid levels in the tank. The tank is also provided with a closed cover thereon to retard escape of noxious gases and including means for introducing cold tar into said low temperature vat. Means are provided for removing heated tar from the high temperature vat without removing the cover therefrom whereby the tar flows freely from the low temperature vat to the high temperature vat and the escape of noxious gases from the tank is thereby restrained.

Abstract: An improved arrangement for preheating a charge of raw material, illustratively an alloying charge, with hot gases prior to application of such charge to a ferroalloying kiln or other electric furnace is described. The charge to be preheated is loaded into a main vertically disposed reservoir which communicates at its bottom end with a combustion chamber adapted to generate the hot gases for preheating. A perforated transition cylinder is vertically disposed within the combustion chamber. Hot gases flow into the interior of the transition cylinder through the apertures and are directed upwardly through the charge stored in the main reservoir, thereby effecting the desired preheating action. The gases emerging from the top of the main reservoir enter a smoke chamber, from which they are discharged into suitable scrubbing and ventilating facilities. The preheated charge is selectively introduced into the electric furnace from the main reservoir via the transition cylinder.

Abstract: A high efficiency aluminum scrap melting system is provided in which a portion of the hot combustion gases employed to melt the aluminum in a hearth is recycled through scrap-receiving preheat compartments to preheat scrap and volatilize contaminants as the scrap is fed to the hearth, the remainder of the hot combustion gases leaving the hearth as hot exhaust gases being optionally employed through a recuperator to preheat air which is fed to a combustion burner system used to burn hydrocarbon fuel and provide heat for the overall system. Energy available in the contaminants also supplements the energy supply to the system.

Abstract: A process for melting scrap metal is disclosed which comprises superheating a quantity of molten metal to at least 1400.degree. F in a metal heating furnace, forming a scrap melt by placing the superheated metal in contact with a quantity of scrap metal to submerge the scrap metal therein, removing impurities from said scrap melt and placing said scrap melt within said heating furnace and then repeating said superheating step. The apparatus in accordance with the present invention comprises a metal heating furnace provided with an improved heat transfer means comprising thermally conductive refractory tiles located between the heat source of said furnace and said molten metal.

Abstract: A system for melting metal scrap in a molten melting media comprises a housing having an upper portion wherein the melting media and scrap are brought together to initiate melting. The housing also has a lower portion in which a volute is located. An impeller, having a central hub, a circumferential band surrounding the hub, and canted vanes projecting radially from the hub to the band, is positioned in the lower portion of the housing to cooperate with the volute so that upon rotation of the impeller, metal scrap and melting media are moved downwardly and out of the housing.

Abstract: A scrap preheating system of the type employing a conveyor upon which the scrap is placed, an elongate burner hood surrounding the conveyor and burners within the hood which direct flames upon the scrap. The side walls of the burner hood include an elongate exhaust chamber and side wall ports between the exhaust chamber and the interior of the hood. An exhaust fan induces a negative pressure under the hood through the exhaust chambers which pulls the unburned hydrocarbons from under the hood through the side wall ports into the exhaust chamber. Additionally, air is drawn upwardly between the conveyor and side walls of the hood and through the side wall ports into the exhaust chambers wherein combustion is completed and pollution reduced. The length of hood and burner array exceeds the length of scrap material on the conveyor. The conveyor is periodically jogged during the preheating cycle to slightly advance and mix the scrap and only those burners positioned above the scrap are operated as it advances.

Abstract: A non-ferrous metal is recovered from a batch of scrap material by combustion of a fuel to generate heat and transmittal of said heat to the material by convection flow. The flow rate of fuel is regulated to obtain and maintain an optimum temperature below the melting point of the metal causing decomposition of non-metallics in the batch of scrap material within a non-oxidizing atmosphere.

Abstract: A method and apparatus for moving molten media such as molten metal or molten salt through a metal treating system utilizing a vaned disc immersed in the media and located in a cylindrical portion of an open-ended volute so as to provide above the disc a body of the media having an unconfined surface.

Abstract: This invention relates to an improved method of melting metal, particularly reactive metals, such as aluminum, wherein heated molten metal is withdrawn from a first chamber and a portion of the withdrawn molten metal is transferred to a second chamber containing solid metal so as to melt same and a portion of the withdrawn metal is recirculated to the first chamber so as to maintain melt homogenuity therein.

Abstract: A system for hot de-oiling and hot briquetting material wherein the material is heated to burn off or vaporize foreign substances and is then transported to a briquetting machine for forming of the material into briquets. The improvements of the invention relate to furnace constructions and to methods of operation for heating the material. The furnace constructions comprise a combustion zone for the material being fed into the system. The material is introduced in two parts comprising coarser material introduced at an upper level and fines and air introduced at a lower level with combustion gases from the lower level being fed upwardly for contact with the coarser material. An outlet is defined by the constructions and means are provided for moving the materials within the furnace to the outlet and for delivering the materials to briquetting equipment.