Abstract: A process for generating in-situ low-cost atmospheres suitable for annealing and heat treating ferrous and non-ferrous metals and alloys, brazing metals and ceramics, sealing glass to metals, and sintering metal and ceramic powders in a continuous furnace from non-cryogenically produced nitrogen containing up to 5% residual oxygen is presented. The disclosed process involves mixing nitrogen gas containing residual oxygen with a pre-determined amount of a reducing gas such as hydrogen, a hydrocarbon, or a mixture thereof, feeding the gaseous mixture through a non-conventional device into the hot zone of a continuous heat treating furnace, converting residual oxygen to an acceptable form such as moisture, a mixture of moisture and carbon dioxide, or a mixture of moisture, hydrogen, carbon monoxide and carbon dioxide, and using the resultant gaseous mixture for annealing and heat treating metals and alloys, brazing metals and ceramics, sintering metal and ceramic powders, and sealing glass to metals.

Abstract: A process for producing low-cost atmospheres suitable for annealing, brazing, and sintering non-ferrous metals and alloys from non-cryogenically produced nitrogen containing up to 5%, residual oxygen is disclosed. According to the process, suitable atmospheres are produced by 1) pre-heating the non-cryogenically produced nitrogen stream containing residual oxygen to a desired temperature, 2) mixing it with more than a stoichiometric amount a hydrocarbon gas, 3) passing it through a reactor packed with a platinum group of metal catalyst to reduce the residual oxygen to very low levels and convert it to a mixture of moisture and carbon dioxide, and 4) using the reactor effluent stream for annealing, brazing, and sintering non-ferrous metals and alloys in a furnace.

Abstract: An improved process for producing high-moisture containing nitrogen-based atmospheres suitable for oxide and decarburize annealing of carbon steels from non-cryogenically generated nitrogen is presented. These nitrogen-based atmospheres are produced by 1) mixing non-cryogenically generated nitrogen containing less than 5.0 vol. % residual oxygen with a specified amount of hydrogen, 2) humidifying the gaseous feed mixture, 3) feeding the gaseous mixture into the heating zone of a furnace through a diffuser, and 4) converting in-situ the residual oxygen present in it to moisture. According to the present invention, the total amount of hydrogen required for producing suitable atmospheres can be minimized by simultaneously humidifying the feed gas and controlling the residual oxygen level in it. The key features of the present invention include a) humidifying the feed gas prior to introducing it into the heating zone of a furnace operated above about 600.degree. C.

Abstract: An apparatus is disclosed for performing thermomechanical processing of gears in which precise control of the thermal, metallurgical and mechanical action during the forming process is maintained. The apparatus comprises an induction heating system which reaustenitizes the surface of the gear with minimum decarburization, a material transfer system which provides timely operations on the work piece, tooling and fixture adjustments which provide accurate initial conditions for forming, and a process control architecture that provides the precise sequence and timing necessary to achieve metallurgically sound and dimensionally accurate gears. Using this invention the induction heating cycle can be controlled from the peak, average or minimum gear surface temperature detected with a high response optical pyrometer. An inert environment is maintained around the workpiece during the induction heating and transfer to quenching above the M.sub.s temperature.

Abstract: A probe (14) comprises a tubular electrical conductor (15) supported by a sleeve of insulating material (16). The two ends of the conductor are connected to couplings (23, 24) for the circulation of a reducing gas through the entire length of the conductor, as well as to an electric circuit (20) kept at a constant voltage and hence permitting measurement of the resistance in a segment (15c) of the conductor which is exposed to the atmosphere of a furnace, the resistivity of the segment varying as a function of the carbon content of the wall of the conductor.

Abstract: An apparatus for adding a predetermined amount of inoculant into a molten metal stream having a conveyor means which accurately provides a desired amount of inoculant to a holding chamber mechanism which becomes pressurized and delivers the inoculant under pressure into the molten metal stream. A programmable controller regulates the apparatus to inject accurately measured amounts of inoculant in an automated fashion into the molten metal stream as it fills varying sized molds.

Abstract: A method and apparatus for monitoring reflective ash deposited on a furnace wall to be cleaned, comprises an infrared video camera or other mechanism for taking an infrared image of the furnace wall. The image must include an area to be cleaned by the waterblowing as well as a surrounding uncleaned area. Photo detectors or other mechanisms are utilized to measure the image intensity at locations on the cleaned and uncleaned areas with a ratio between the intensities being taken. The cleaned area has low reflectivity and is dark compared to the uncleaned area which is white and has high image intensity. The image intensity ratio between the cleaned area and the uncleaned area thus rises from a low level immediately after waterblowing to a high level which approaches unity as the initially cleaned area becomes as unclean as the uncleaned area.

Abstract: A method and apparatus for controlling the operation of a water lance for water cleaning a furnace wall comprises a sensor or calculation equipment to derive the furnace wall emissivity and equipment that compares the emissivity to a programmed low setpoint that represents an unclean furnace wall and poor furnace operation. Water lance operation is initiated when the low setpoint is reached. The speed at which the water lance operates is also adjusted according to peak emissivity levels which are measured or derived from the furnace walls after each cleaning.

Abstract: A method and apparatus of initiating and terminating the cleaning of a furnace wall to remove reflective ash which been deposited thereon, comprises a video or infrared monitor which monitors the light being reflected from the furnace wall or the ratio of the reflected to the incident light, the intensity of reflected light or ratio of the reflected to the incident light increasing as additional reflective ash is deposited. When the reflected light intensity reaches a selected value, cleaning is initiated and measurement of the reflected light is continued to monitor when the reflected light reaches a low substantially constant intensity. At that point, the cleaning operation is terminated since the constant reflected light intensity indicates a substantially clean condition.

Abstract: Heat treating metals by continuous longitudinal passage of metallic pieces in an elongated treating zone under controlled atmosphere having a high temperature upstream end where the controlled atmosphere comprises nitrogen and reducing chemical substances, such as hydrogen, possibly carbon monoxide, and a downstream cooling end under an atmosphere essentially formed by introducing nitrogen. In the high temperature upstream end, the nitrogen which constitutes the atmosphere is supplied by introducing nitrogen with a residual oxygen content not exceeding 5%, the reducing chemical substances being present at any moment in amounts at least sufficient to eliminate oxygen introduced with nitrogen. The nitrogen introduced in the downstream cooling end is substantially free of oxygen. Application of the process to the annealing of metallic pieces.

Abstract: A probe (14) comprises a tubular electrical conductor (15) supported by a sleeve of insulating material (16). The two ends of the conductor are connected to couplings (23, 24) for the circulation of a reducing gas through the entire length of the conductor, as well as to an electric circuit (20) kept at a constant voltage and hence permitting measurement of the resistance in a segment (15c) of the conductor which is exposed to the atmosphere of a furnace, the resistivity of the segment varying as a function of the carbon content of the wall of the conductor.

Abstract: Process and apparatus for post combustion of reaction gases generated in a molten iron bath above the bath by means of at least one jet of oxidizing gases, whereby energy thereby produced is transferred to the bath and whereby the or each jet of oxidizing gases is injected with a swirl through one or more tuyeres towards the surface of the bath or the or each jet of oxidizing gases is injected in the form of a hollow jet through one or more tuyeres towards the surface of the bath.

Abstract: A process is provided for preparing crystalline ceramic superconductor materials, which comprises preparing a mixture of particulate crystalline ceramic superconductor precursors selected to form upon heat processing a crystalline ceramic superconductor material; subjecting said mixture to calcination at an elevated reaction temperature sufficient to form a crystalline ceramic material, while entraining and fluidizing said mixture in a flow of hot calcining gas; and then quenching the crystalline ceramic material to a temperature below calcination temperature; the quenching step can be followed by annealing and cooling the resulting crystalline ceramic material in the presence of oxygen to form and maintain a selected superconducting crystalline structure in the material.

Abstract: A method of gas carburizing and hardening a steel article and a continuous furnace therefor. The method includes the steps of carburizing the article in a carburizing atmosphere at atmospheric pressure, heating the article in a vacuum for a predetermined period of time, and hardening the article.

Abstract: An internal gas generator in combination with a standard heat treat furnace is provided for producing either an endothermic product gas or a purge gas. The generator includes a reaction tube containing alternating packed beds of a highly active catalyst and inert heat transfer particulates. The reaction tube is surrounded by an elongated tubular heating element which heats the reaction tube, the combination producing an acceptable product gas in a small arrangement suitable for retrofit applications to existing furnaces. A flanged mounting permits the reaction tube to be easily removed for standard replacement in the event of catalyst poisoning and the like.

Abstract: Fluidized-bed type carburizing furnace means of the class provided with a path for circulation of the furnace gas of a fluidized-bed type carburizing furnace is improved by incorporation therein of ejector means for spouting compressed gas into the circulation path. The circulation path comprises an outlet pipe emanating from the furnace gas outlet of the fluidized-bed type carburizing furnace, a cyclone connected through the medium of the outlet pipe to the fluidized-bed type carburizing furnace, and a discharge pipe emanating from the cyclone and joined to the furnace gas inlet of the fluidized-bed type carburizing furnace. The ejector means comprises a constriction formed in the discharge pipe and a feed pipe for compressed gas having the leading end thereof inserted into the constriction.

Abstract: A method of controlling independently of each other the stirring strength of a jet of oxygen gas and the flow rate of the oxygen gas to be blown onto a molten metal bath in a top-blowing oxygen furnace is disclosed. The method comprises providing an oxygen supplying conduit with a means of detecting the temperature of the supplied oxygen gas, a means of detecting the pressure thereof, and a means of heat-exchanging with the supplied oxygen gas, controlling the temperature and pressure of the oxygen supplied so that the stirring strength of the jet of oxygen gas and/or the flow rate of the oxygen gas are controlled independently of each other with the top-blowing lance being kept at a predetermined position.

Abstract: A heat treatment apparatus for metals or metal articles has a fluidized-bed furnace for heating the metals and a cooling chamber disposed above the furnace so as to communicate with a heating chamber of the furnace through a partition capable of being opened and closed, so that the metals can be cooled immediately after heated. The apparatus further includes a circulating circuit arrangement with a heat-resisting fan for circulating together or separately heated furnace gas and cooling fluid. Flow rate of the circulating furnace gas and/or cooling fluid is controlled by a flow rate control device provided in the circulating circuit.

Abstract: This application discloses a method and apparatus for conducting various metal treatment processes including nitriding, carbonitriding, nitrocarburizing, surface activation, and selective oxidation in any desired sequence in the same fluidized bed furnace. The apparatus comprises a fluidized bed furnace having a humidifier system including a humidifier and superheater and the method involves exposing a metal workpiece sequentially to at least two separate metal treatment atmospheres in a fluidized bed furnace.

Abstract: The exhaust-gas treatment system of a sealed-type steel converter is operated at the time of an emergency during blowing by a method which comprises stopping the blowing of oxygen, opening an emergency air suction device connected to the hood while, at the same time, maintaining a converter controlling damper at its degree of opening at the time of stopping of the blowing, disconnecting the skirt of the hood from the converter mouth, and opening the damper to a specific degree of opening. By this simple method, sudden and great pressure drops within the converter are prevented, whereby CO gas of high purity can be efficiently recovered without the occurrence of damage to parts of the system due to abrupt pressure difference and explosion of CO gas.

Abstract: The invention concerns cooling apparatus for strip metal of the kind comprising a series of spaced cooling rolls around which the strip metal is passed such that it follows a serpentine path and is cooled by contact with the rolls, and elongate gas jet devices disposed widthwise of the strip opposite the outer surface parts of respective cooling rolls in contact with the strip.

Abstract: The invention relates to a process and an apparatus for preparing binder-free hot-briquets for smelting purposes from ferrous pyrophorous, finely divided solids, such as dry steelmaking-filter dust or slightly granular sponge iron from direct-reduction plants. Before the briquetting stage, oxidizing gas is blown at a temperature of more than 200.degree. C. through the finely divided dry solid containing more than 4% by weight of metallic resin. The flow rate of this gas is controlled in such a way that oxidation of some of the metallic iron raises the temperature of the finely divided solid to 450.degree. C. to 650.degree. C. This is followed by hot-briquetting.

Abstract: Railroad rails having improved wear resistance, are produced by controlled forced cooling from above the austenite transformation temperature, to produce rails having a fine pearlite metallurgical structure in the head portions of the rails. Apparatus comprising a series of cooling headers utilizing a liquid cooling medium, such as unheated (i.e., cold, or ambient temperature) water, alternating with a series of air zones, is preferably arranged in line with the production rolling mill, to receive hot rails as they emerge from the mill, without the necessity of intervening reheating. A roller type restraint system transports the rails through the cooling apparatus, while restraining them in the appropriate position.

Abstract: In the gas carburization of steel, a steel part is exposed in a carbon-enriched atmosphere of a furnace to a diffusion process to form a boundary layer with an increased carbon content, determined as a function of the distance from the surface. The values of importance for the diffusion process are determined intermittently and used as control parameters to affect the diffusion process. The flow of carbon diffusing directly through the surface of the steel part serves as the measured value. The supply of the carburizing gas is controlled as a function of this value.

Abstract: An apparatus for regulating the feed or delivery of hot air in the tuyere stock of a shaft furnace, and a tuyere stock which incorporates such a regulating apparatus is presented. The regulating apparatus may be used in conjunction with a tuyere stock for a shaft furnace (the structure of which is well known) and consists of an articulated pipe connecting a large circular conduit to a nozzle and which is fitted internally with a refractory lining having an internal channel therethrough for the passage of air. The regulating apparatus of the present invention comprises a valve substantially in the form of a disc which is adapted to operate in a spherical portion of the internal channel described above. The disc is removably mounted on the end of a rod, the rod being rotatably and hermetically mounted in a tubular support integral with the wall of the tuyere stock and connected on the outside thereof to a mechanism which serves to pivot both the rod and the valve about the longitudinal axis 0 of the rod.

Abstract: An apparatus and a process for the zone-annealing of a workpiece (1) consisting of a high-temperature material, in which the workpiece (1) is hung on a suspension device (2) actuated via a roller (3) driven by a drive motor (4) and is provided with a plate-shaped covering screen (10) having an orifice. For the dipping of the workpiece (1), there is underneath the latter a salt bath (5) which is enclosed in an insulating vessel (6) and is provided with a heating system (7) with centrally symmetrical guide plates (8) and which is closed off at the top by means of a floating insulating cover (9). The cooling of the part of the workpiece (1) which is not immersed is guaranteed by a cooling body (11) through which cooling air (14) flows and which has a central passage (12) and, at the lower end of the passage (12), a projecting edge (13) serving as a stop for the covering screen (10).

Abstract: A method of and apparatus for continuously quenching a steel plate with cooling water, by passing the steel plate through a water storage vessel containing the cooling water. The cooling water for cooling the upper side of the steel plate is introduced into the upper section of the water storage vessel from an upper portion of the latter and is exhausted from an upper portion of the same through, for example, overflow. The cooling water for cooling the lower side of the steel plate is introduced into the lower section of the water storage vessel from a lower portion of the latter and exhausted from a lower portion of the same. The cooling water is agitated and moved by impellers disposed in the upper and lower sections of the storage vessel in the direction of movement of the steel plate or in the direction opposite to the direction of movement of the steel plate which is clamped and fed linearly through the water storage vessel by means of upper and lower rolls.

Abstract: A process and apparatus for heating a steel bath charged with scrap which efficiently utilizes converter waste gas to supplement external energy sources is presented.

Abstract: A method of sequentially annealing and then hardening long metal components (1,2,3,4) made of fine or special steel with an austenitic structure, said method including at least one annealing operation by supplying heat from the outside in a reducing or neutral atmosphere and one quenching operation by contact with a flow of cooling fluid and an apparatus for putting said method into practice.The flow rate and the temperature of the cooling fluid are adjusted so that the components undergo no transformation of their austenitic structure during hardening.Application to annealing and hardening armoured electric components with conductor cores, inorganic insulant coatings and outer sheaths made of austenitic steel.

Abstract: A furnace for heating steel articles and so on without oxidation and decarbonization. In the furnace, non-oxidation gas atmosphere with or without cementation characteristics is produced and regenerated by subjecting the air to carbon elements and heat at a reaction chamber provided within the furnace or closely thereto, and the gas atmosphere is circulated through a substantially closed circuit with the said reaction chamber connecting outtake and intake openings of the furnace.

Abstract: A melt of magnesium-containing nodular iron partially fills an enclosure forming a space above the melt which fills with the vapor of magnesium evaporated from the melt. Magnesium is fed into the space where the magnesium vaporizes and increases the vapor pressure so as to drive magnesium into the melt and increase its magnesium content.

Abstract: A pulverized material, particularly coal or lignite, is maintained in a fluidized state in a storage container and is released therefrom into a carrier gas stream. The gas for causing fluidization and maintaining a pressure in the container which is greater than the carrier gas pressure is in part obtained by recycling gas vented from the container, the vented gas being filtered and increased in pressure. The vented gas may also be employed to aid in the delivery of the pulverized material into the container.

Abstract: A process for the direct reduction of iron ore in a shaft furnace having an upper reducing zone and a lower cooling zone in which reducing gas is introduced to the furnace at the bottom of the reducing zone around the periphery of the furnace, exhausted reducing gas or top gas is removed from the top of the furnace, cleaned, mixed with additional hydrocarbons, and reinjected into the furnace below the reducing zone. The hot reducing gas is injected serially into different sectors of the cross-section of the furnace and at varying velocities to force upflowing cleaned top gas to change its flow path or its flow rate, or both, periodically. Apparatus for accomplishing the method is also disclosed.

Abstract: Apparatus is provided for preventing reaction forces on a flow control valve from affecting measurements of particulate feed rate, where such measurements are made using weighing devices to determine the amount of particulates in a supply container as a function of time. The apparatus includes means for applying sufficient compressive prestress to spacer bars for absorbing reaction forces on the valve so that extension of the staybars is prevented during particulate feeding. Movement of the container due to reaction forces on the valve is prevented and particulate feed rate errors are substantially eliminated.

Abstract: Hot briquetting apparatus for ferrous or non-ferrous particles has a furnace having upper and lower chambers. The particles are supplied to the lower chamber and leave the lower chamber through a discharge tube to enter a briquetting press. A passage is performed between the lower and upper chambers and sensing means sense the constituents of the gases in that passage. Control means control the air-to-fuel ratio of a zone of the lower chamber. The control means are connected to the output of the sensing means so as to maintain the atmosphere within the zone as a reducing atmosphere, the whole of the lower chamber being a reducing atmosphere.

Abstract: Apparatus for adding materials, especially powdered or granular materials, to a flowing stream, e.g. of molten metal, comprises a nozzle for compressed gas, blowing the additive into the stream, and a detector that detects the stream and switches the flow of additive on and off according to whether the stream is present or absent. The detector is preferably of a non-contact type, sensing radiation from the stream, preferably visible light. The rate of flow of additive can be adjustable. There can be a fail-safe optical detector arrangement monitoring the flow of additive and signalling an alarm if the flow fails or if the nozzle is blocked. The timings of the start and end of the flow in relation to the detection of the metal stream are independently adjustable to ensure that the additive and metal coincide.

Abstract: A gravity fed water bath process treats waste water from spray rinses containing compounds of copper and like heavy metals. For displacing heavy metals, such as copper, the bath has a substantially pure metal with an electrode potential greater than the heavy metal contained in the rinse water. A system for controlling the pH level of the water bath treatment and for supplying acid at the beginning of the bath, and alkaline at the end of the bath provides a highly acidic pH level for the water bath and heavy metal removal chamber, and adjusts the pH level of the discharged water for satisfactory deposit in municipal sewer systems.A method for displacing the heavy metal from the compound in solution requires exposing the heavy metal compound to a substantially pure metal having an electrode potential greater than the heavy metal of the compound, in an acidic bath whose pH level is controlled.

Abstract: A system is described for precise monitoring and control of the carbon content of the atmosphere of a furnace such as a carburizer used in the heat-processing of steel parts. The disclosed apparatus includes a sampling system for withdrawing a gas sample from the atmosphere within a furnace and an analyzer for producing signals indicative of the partial pressures of at least two gaseous components such as carbon dioxide and carbon monoxide. The analyzer preferably utilizes selective absorption of narrow-band infrared radiation signals in determining these signals. A processor combines the signals indicative of partial pressures with parameters obtained from measurements of furnace temperature, and calculates carbon potential of the furnace atmosphere. The processor output is coupled with an atmosphere control which maintains desired levels of carbon potential in the atmosphere of the furnace by, for example, regulating the flow of an enriching gas to the furnace.

Abstract: This invention relates to the generation of an atmosphere for the heat treatment of metals, incorporating an alcohol of the methanol type that decomposes by cracking.A generating plant comprises a nitrogen circuit connected to a pressure source, an alcohol circuit connected to a pressurized tank containing the alcohol in the liquid phase and an injector arranged to feed the alcohol and nitrogen into the furnace in the form of a mist of alcohol within a jet of nitrogen.The invention is applicable in particular to the hardening, heating prior to quenching, and annealing of steels.

Abstract: For use in a system for injecting powdered reagent into a pool of molten metal through a lance whose discharge end is submerged in molten metal and to which powdered reagent is conveyed by a flow of carrier gas, sensing means is arranged to derive a signal dependent upon the rate of flow of carrier gas to the lance and after predetermined time delay the signal is applied to control means so as to effect a shut off of the supply of powdered reagent and of the flow of carrier gas and to elevate the lance out of the pool of molten metal whenever the lance becomes clogged on the one hand or ruptured on the other.

Abstract: Sponge iron is carburized in the cooling zone of a vertical shaft iron ore reduction reactor by causing a carbon-containing gas to circulate in a closed loop including the cooling zone of the reactor and an external conduit containing a quench cooler and a pump. Improved control of the carburization of the sponge iron is achieved by measuring the specific gravity of the circulating gas and using the measured specific gravity value as a control variable effectively to regulate the flow of make-up carbon-containing gas to the cooling loop.

Abstract: Apparatus for injecting a predetermined amount of a selected free flowing granular material into a body of molten metal comprising a plurality of supply hoppers for receiving a plurality of supplies of different granular materials to be injected each supply hopper having a control gate on the lower end of its outlet chute for controlling the flow of granular material within the supply hopper outwardly thereof into a receiving hopper which feeds it to an incremental volume forming position.

Abstract: An automatic leaching system for the hydrometallurgical production of zinc comprising a pH meter and means for detecting the feed rate of calcine. The pH meter is provided with means for automatically washing the electrodes thereof so as to be capable of continuously and automatically detecting the pH value of the slurry obtained by mixing a spent electrolyte with the calcine. The system comprises a feedback control circuit and a feed-forward control circuit in which the flow rate of the spent electrolyte supplied to the system is the manipulated variable, and the pH value of the slurry is the controlled variable. These control circuits are used for the pH control so that the pH value of the slurry can be maintained constant by controlling the flow rate of the spent electrolyte.

Abstract: Method and apparatus is provided for quenching a metal workpiece by an inert gas at ambient temperature. Jet streams of gas coolant at high velocity and flow rates are directed in a balanced arrangement against opposing workpiece sides and the jets are correlated to the thickness of the workpiece sections to achieve uniform cooling rates with minimal workpiece distortion. A flow straightening grid in combination with a variable sized aperture plate achieves the desired jet streams in an adjustable plenum arrangement which directs the streams against the top and bottom surfaces of the workpiece.