Abstract: Slopping of emulsion from the mouth of a basic oxygen refining vessel is prevented during oxygen refining by introducing inert gas into the vessel when slopping is imminent or has begun. The preferred method is to inject argon in admixture with oxygen through the oxygen lance at a flow rate of from 5 to 30 percent of the oxygen flow rate.

Abstract: A process for thermochemically scarfing a metal workpiece comprising:Preheating a spot on the surface of the workpiece where the scarfing reaction is to begin by directing a post-mixed preheating flame at the spot. The preheating flame is formed by:(a) discharging at least one stream of preheat oxidizing gas and at least one stream of preheat fuel gas from separate ports in such a manner that the streams impinge external to their discharge ports, above the work surface and in such manner that the axes of the streams form an acute included angle between them, and(b) stabilizing said preheating flame by discharging a low-intensity stream of oxidizing gas. The stabilizing stream is directed in the same general direction as the direction of the flame or it may be directed such that the angle formed by the low intensity stream and the forward axis of the flame is from 10.degree. to 90.degree..

Abstract: A device for holding a transparent tube in an optical sensor while excluding light from external sources. The device is automatically positioned for excluding external light upon insertion of the tube into the optical sensor.

Abstract: Disclosed herein is a control circuit employing instantaneous and delayed action bistable switching elements for use in controlling the flow of refuse in a multiple channel, extrusion type briquetting or pelletizing system wherein the refuse is supplied from a conveyor to a common chute feeding a pair of extrusion-type compactors. A vane arrangement in the common chute is driven in a reciprocating cyclical manner to feed the refuse in an alternating manner to the compactors. The control circuit disclosed herein senses the cyclical action of the reciprocating vane and controls in turn the conveyor system which supplies refuse to the chute. Certain deviating actions of the vane system indicate conditions signalling an incipient jam in the system flow. The control circuit, in sensing such actions and in concomitantly interrupting the feed of refuse, corrects the feed rate to alleviate the potential jam-producing conditions.

Abstract: A thermochemical scarfing process and apparatus capable of reducing the amount of smoke discharged to the atmosphere and/or of preventing the formation of "secondary" fins when spot scarfing, comprising:(a) scarfing oxygen is directed against a reaction zone of molten metal on the surface of the workpiece to produce a scarfing reaction, and(b) relative movement is provided between the oxygen stream and the workpiece, said reaction forming a molten puddle in front of the reaction zone that grows larger as the cut progresses, wherein the improvement comprises:(c) directing at least one stream of non-reactive fluid to form a fluid, sheet-like curtain that provides a cover over the reaction zone and at least the rear portion of the molten puddle in such manner that said curtain forms a pocket with the surface of the workpiece.

Abstract: A process for thermochemically scarfing a metal workpiece comprising:Preheating a spot on the surface of the workpiece where the scarfing reaction is to begin by directing a post-mixed preheating flame at the spot. The preheating flame is formed by:(a) discharging at least one stream of preheat oxidizing gas and at least one stream of preheat fuel gas from separate ports in such a manner that the streams impinge external to their discharge ports, above the work surface and in such manner that the axes of the streams form an acute included angle between them, and(b) stabilizing said preheating flame by discharging a low-intensity stream of oxidizing gas. The stabilizing stream is directed in the same general direction as the direction of the flame and proximate to the impingement of the preheat oxidizing gas and preheat fuel gas streams.Steps (a) and (b) are continued until the spot reaches its oxidizing gas ignition temperature.

Abstract: A method for automatically controlling the restrictors in a ram-tube type refuse compacter or pelletizer. Variable restrictors near the discharge end of the tube control the compaction pressure exerted on the refuse as it is forced through the tube. The restrictors are capable of being moved inward and outward on each ram stroke in response to changes in the ram pressure required to advance the compacted refuse through the tube. The method comprises:(1) measuring the ram pressure during the last smallest practicable increment of forward ram travel,(2) adjusting the restrictors slightly inward if the pressure measured in step (1) is less than a predetermined pressure P.sub.1,(3) measuring the ram pressure when the ram is at the lock-out point, normally about 6 inches from the forward end of its stroke,(4) overriding step (2) by making no inward restrictor adjustment if the pressure measured in step (3) is less than a predetermined pressure P.sub.

Abstract: An instantaneous scarfing cut on the surface of a metal workpiece can be made by:(a) causing relative motion between the workpiece and a stream of scarfing oxygen gas, and simultaneously therewith(1) impinging at least one laser beam on the work surface so as to produce a heated path of desired length across said surface relative to its direction of motion, said heated path being produced by the laser beam heating a series of points on said surface to their oxygen ignition temperature, and(2) impinging a stream of scarfing oxygen onto said heated path, thereby causing an instantaneous scarfing cut to begin along said path, and(b) continuing the flow of scarfing oxygen until the desired length of cut has been produced.

Abstract: Basic-oxygen steels containing a high, controlled level of nitrogen are made by:(a) introducing a nitrogen-rich gas into the melt during the latter portion of the decarburization step, through the oxygen lance together with the oxygen, in an amount sufficient to impart at least 100 NCF of nitrogen per ton of molten metal, and in such a manner as to promote intensive interaction of the nitrogen-rich gas with the molten metal,(b) refining the melt with the oxygen and nitrogen-rich gas by blowing the melt to a final manganese content of 0.10 percent or less, and(c) maintaining the partial pressure of nitrogen in the vessel head-space at least equal to that calculated to be in equilibrium with the aim dissolved nitrogen content of the melt at 1600.degree. C.

Abstract: A scarfing nozzle and method for producing a fin-free scarfing cut at least as wide as the width of the nozzle. The method is characterized by directing a stream of oxygen at the spot to be scarfed from a scarfing nozzle which restricts the flow of oxygen at the edges of the oxygen stream such that the flow at the edges is insufficient to scarf the workpiece but sufficient to oxidize molten metal at the edges of the reaction zone to produce a fin-free scarfing cut at least as wide as the width of the nozzle. The nozzle is particularly useful for spot scarfing in gang arrangement.

Abstract: A vertical shaft furnace for the pyrolysis of pelletized refuse, having a hearth in the base provided with a refuse bed support structure comprising a plurality of cooled, refractory support members, extending radially inward from the wall toward the axis of the hearth. The support structure is characterized by having a plurality of peripheral spaces extending through side structure and converging in the downward direction, each of the peripheral spaces being formed, at least in part, by the side wall surfaces of adjacent support members and the inside surface of the hearth.

Abstract: Method for providing surge capacity and for smoothing out the flow rate of refuse in a system, wherein refuse is loaded onto a moving conveyor at variable or intermittent rates, by (1) preventing excess refuse from passing beyond a given point on the conveyor by a rotating leveler, spaced a predetermined distance from the conveyor to permit only the desired level of refuse to remain on the conveyor beyond the leveler, and (2) rotating the leveler at a speed greater than the speed of the conveyor, the direction of rotation of the leveler being opposite to the direction of travel of the refuse on the conveyor. Refuse in excess of the amount desired to be transported by the conveyor is retained behind the leveler as a rolling inventory of refuse, causing the refuse to be discharged from the conveyor at a constant and uniform rate.

Abstract: A device for tapping molten slag of variable composition comprising:A. a metal duct provided with cooling means and having an inlet port at one end and a discharge port at the other, the lower portion of the face of the discharge port being sealed against the leakage of slag by being abutted againstB. a highly heat-conductive, water-cooled metal weir having a surface inclined up and away from the face of said discharge port and terminating in an edge which extends across the face of said discharge port and constitutes the forward most portion of the device. The weir is preferably made of copper and the metal duct lined with a refractory material behind the weir.

Abstract: A method for producing an individual, fin-free, spot scarfing cut on the surface of a workpiece characterized by directing at the spot to be scarfed, which has first been brought to a molten state, an oxygen stream at an inclined angle to the work surface, the intensity of said oxygen stream being gradually diminished toward its lateral edges so that the flow of oxygen at the edges of said stream is insufficient to scarf the workpiece, but sufficient to oxidize molten metal at the edges of the scarfing reaction zone, thereby preventing molten metal from solidifying on the work surface along the edges of the scarfing cut in an unoxidized state.

Abstract: A method and apparatus for making an instantaneous thermochemical start on the surface of a metal workpiece.The method resides in the use of laser beam focused to a small spot to bring the ferrous workpiece to ignition temperature in combination with a high intensity oxygen jet to cause the initiation of the thermochemical reaction. The laser beam may impinge the workpiece at a point about 1 cm behind the spot where the oxygen impinges the workpiece surface to a point about 10 cm ahead of such spot. Accordingly, the laser beam may penetrate the high intensity oxygen jet and still cause the thermochemical reaction to start instantaneously.The apparatus resides in a scarfing machine having a scarfing nozzle, an oxygen spreader nozzle and a laser assembly associated therewith. The oxygen spreader nozzle is mounted so as to provide high intensity oxygen jet on the surface of the workpiece ahead of the scarfing oxygen effluent from the scarfing nozzle.

Abstract: An improved argon-oxygen decarburization process for refining stainless steel comprising injecting a three component gas mixture consisting of oxygen, argon and carbon dioxide into the molten steel during decarburization. .[.The critical upper limit of CO.sub.2 injection into the melt is defined, below which the carbon removal efficiency is improved..]. The preferred flow rate of CO.sub.2 during each of the three principal phases of decarburization is set forth as a function of the flow rate of oxygen and argon, bath temperature and carbon content of the melt.