Abstract: Municipal or other solid waste is delivered in loose form to a processing facility where it is compacted into a supply chute adjacent the upper portion of a reactor. The compaction serves to remove most of the air and some of the water from the waste as well as to seal the reactor against air infiltration. The supply chute is equipped with a number of pusher units which are capable of pushing a portion of the compacted waste in the form of a block into the reactor. The blocks of compacted waste are deposited in the top of the reactor in response to a signal related to the height of waste in the reactor. A pivotally and extendible mounted plasma arc torch is employed as a heat source to pyrolyze organic waste components to generate desired by-product gases. Air and steam are added in controlled quantities to improve the operational efficiency and the by-product gas composition. Residual materials which do not pyrolyze are melted and cooled into a substantially inert vitrified mass.

Abstract: A system is disclosed in which municipal mixed solid waste is delivered to a processing facility where it is compacted before being placed into a reactor. The compaction apparatus serves to remove most of the air and some of the water from the waste as well as to seal the reactor against air infiltration. A transfer apparatus, in response to a signal relating to the height of waste in the reactor, sequentially deposits blocks of compacted waste in the top of the reactor when the height is low. The reactor has a pivotally and extensively mounted plasma arc torch as a heat source which is effective to pyrolyze organic waste components to generate desired by-product gases. Air and steam are added in controlled quantities to improve the operational efficiency and the by-product gas composition. The residual materials which do not pyrolyze are melted and cooled into a substantially inert vitrified mass.

Abstract: The present invention provides an apparatus for the melting and subsequent solidification of fine particulate material by means of a plasma torch. The fine particulate material is introduced into a furnace having a plasma torch to a depth sufficient to cover the plasma flame produced by the torch. When operative, the torch generates a heat at low gas flow, which both allows the fine particulate material to rest with little disturbance and to transfer large amounts of heat energy to the fine particulate, effectively preheating the fine particulate material for more efficient melting. The melt may, for example, be solidified into a block for building use, into fibers by means of pressurized air passed through a venturi nozzle or into other useful forms.

Abstract: A plasma arc torch is provided which is convertible in the field as to be able to operate in either a transfer arc mode or non-transfer arc mode. The plasma arc torch comprises a torch body having channels formed for flow of coolant and plasma gas therein. The torch body further comprises an anode and a cathode base and terminates at a threaded connection point. Adapted to be assembled to the threaded connection by means of mating threads is, alternatively, either an end cap or a cathode extension assembly, thereby establishing a plasma arc torch capable of operating in either a transfer arc mode or a non-transfer arc mode. When the end cap is connected, the cathode base is not energized. The cathode extension assembly contains a cathode extension which connects to the cathode base on assembly. Both the cathode base and cathode extension are energized to form the active cathode for the non-transfer arc mode operation.

Abstract: The present invention provides a method for the melting and subsequent solidification of fine particulate material by use of a plasma torch. The fine particulate material is introduced into a furnace having a plasma torch to a depth sufficient to cover the plasma flame produced by the torch. When operative, the torch generates a heat at low gas flow, which both allows the fine particulate material to rest with little disturbance and to transfer large amounts of heat energy to the fine particulate, effectively preheating the fine particulate material for more efficient melting. The melt may, for example, be solidified into a block for building use, into fibers by way of pressurized air passed through a venturi nozzle or into other useful forms.

Abstract: A plasma arc torch is provided which is convertible in the field as to be able to operate in either a transfer arc mode or non-transfer arc mode. The plasma arc torch comprises a torch body having channels formed for flow of coolant and plasma gas therein. The torch body further comprises an anode and a cathode base and terminates at a threaded connection point. Adapted to be assembled to the threaded connection by means of mating threads is, alternatively, either an end cap or a cathode extension assembly, thereby establishing a plasma arc torch capable of operating in either a transfer arc mode or a non-transfer arc mode. When the end cap is connected, the cathode base is not energized. The cathode extension assembly contains a cathode extension which connects to the cathode base on assembly. Both the cathode base and cathode extension are energized to form the active cathode for the non-transfer arc mode operation.

Abstract: A method is disclosed in which a plasma arc torch is used to vitrify and remediate a site containing contaminated soils, resulting from a hazardous material deposit or spill, or contaminated buried objects. The contaminated earthen material or subterranean deposit is pyrolyzed, melted or solidified by the plasma torch which is energized at the bottom of a cased, vertical borehole, and then gradually raised to the surface. An array of boreholes, appropriately spaced, will remediate an entire mass of contaminated material. Similarly, buried objects such as metal drums containing contaminants and underground storage tanks may be selectively remediated at their specific buried depth. Similar use is made of the plasma torch in a second embodiment with the additional step of processing at selected underground locations in the borehole array to create a sealed horizontal layer, vertical cutoff walls or a sealed basin as a barrier against further leaching of contaminants into surrounding soil and groundwater.

Abstract: A method and apparatus is disclosed for removing chevron cracks from the corner edges of a steel billet as it advances in a hot condition from a continuous casting operation. The apparatus includes a framework which mounts four plasma arc torches which are adapted to operate in the non-transfer arc mode, and with the torches being positioned so that the heated plasma engages respective ones of the four corner edges of the billet, to melt and heal any cracks. The framework is cyclically advanced rearwardly and forwardly along the path of travel of the billet, so as to permit effective control of the level of heating and so as to assure all longitudinal portions of the advancing billet are effectively treated.

Abstract: The process of the present invention serves to remediate and reduce the volume of waste materials in a landfill site and increases the useful life of the treated landfill. The process steps involve drilling a series of holes into the waste material mass at proper spacing, inserting and operating a plasma arc torch in each drilled hole to pyrolize, remediate and vitrify the waste materials and allowing the melted materials to cool and harden. During the process, a gaseous by-product is produced and collected in a hood which is attached to scrubbing and chemical cleaning apparatus. The resultant gases are commercially useful as fuel gas and the vitrified residue is significantly smaller in volume than the original waste material volume, thus substantially extending the useful life of the landfill site and ultimately providing a firm foundation for construction.

Abstract: An apparatus for eliminating chevron cracks or other imperfections in the surface of elongate billets as billets pass vertically downwardly through a heating chamber, including a plurality of plasma arc torches. The heating chamber contains a billet mold having an opening complementary in size and shape to the cross-sectional shape of the billet. Heat imparted to the billet in the upper portion of the chamber melts surface portions of the billet. Molten material discharged from the surface portions of the billet forms a pool in an area above the mold opening. As the billet passes through the pool, some of the molten material reattaches itself to the billet surfaces. Billet conveyors pivotally movable between horizontal and vertical positions transport billets to and from the heating chamber, and control the rate at which the billets move through such chamber and through a cooling chamber located beneath the heating chamber.

Abstract: A method and apparatus for in-situ solidifying and stabilizing a mass of unstable foundation soil utilizes a plasma arc torch. The torch is inserted into a drilled and cased hole to a selected depth in a subterranean unstable soil layer and the torch is energized. The intense heat generated by the torch melts the soil material close to the hole and forms a pool of melt while more remote sections are baked to a brick-like consistency or dried and strengthened. Upon cooling, the central melted soil material cools to a hard, vitrified column with physical properties equivalent to a hard, dense rock. Variations of the method apply to a variety of construction support problems and landslide remediation problems.

Abstract: Mixed refuse containing organic and inorganic material forms a column-like mass within a furnace chamber. The column of material is heated by a plasma torch having a forward plasma-emitting end disposed within the lower portion of the column and surrounded by the refuse therein. The height of the stack is maintained at a preselected elevation above the forward end of the torch. Gases produced by pyrolytic conversion of organic components of the refuse are discharged through ports of the chamber. Melted metallic and other inorganic refuse forms a pool upon a hearth of the furnace chamber. The plasma torch imparts circulatory movement to the pool. An injector downstream from the torch directs steam onto material adjacent the surface of the pool. Excess molten material is drained from the pool and the furnace chamber.

Abstract: An apparatus and method is disclosed which is adapted to consolidate and melt reactive metallic materials, and to produce a "first ingot" which is suitable for subsequent evaluation and qualification under existing specifications for such materials in the aerospace industry. The apparatus comprises an enclosed heating chamber adapted to be substantially evacuated of air, and a hearth is positioned within the chamber for supporting the metallic material to be melted. Also, a plasma arc torch is mounted to the heating chamber, which is operable in the transfer arc mode wherein an arc extends from the rear electrode of the torch to the hearth. The rear electrode of the torch is of elongate tubular configuration, which permits a major portion of the length of the arc to be located within the torch itself, which permits the torch to deliver a high level of power in the vacuum environment within the heating chamber.

Abstract: An apparatus and method for heating a metallic melt with plasma torches is disclosed which is characterized by its ability to reduce the amount of contamination that is introduced into the metallic melt during the heating process. The apparatus and method includes a furnace chamber having a hearth for receiving a metallic melt. Mounted to the furnace chamber are a pair of plasma torches and an external electrode that is adapted to contact the metallic melt contained in the hearth. A separate direct current power supply is provided to operate such plasma torch. During operation of the apparatus, two separate circuits of opposite polarity are established through the metallic melt utilizing the plasma torches and the external electrode in contact with the melt. While these circuits are maintained, the external electrode is withdrawn from contact with the melt, thereby establishing a single series circuit which includes both plasma torches, both power supplies and the metallic melt.

Abstract: An apparatus for starting and maintaining a plasma arc is disclosed, which comprises a plasma arc torch composed of a rear electrode and a front tubular member, with the tubular member acting as a collimator in transfer arc operation or as an electrode in non-transfer arc operation. The power circuit includes a main DC power supply, an electrical pulse generator in series with the plasma torch, and a protective capacitor connected between the main power supply and pulse generator. To initiate the arc, a high voltage pulse is generated by the pulse generator, which has sufficient power to strike an arc which extends from the rear electrode to an external workpiece in the case of transfer arc operation. The main power supply is used only to maintain the established arc, and thus may have a relatively small voltage capacity.

Abstract: As apparatus and method is disclosed which is adapted to melt metallic fines, and which is useful for processing metallic fines into a useful form. The apparatus may also be used in the smelting of metallic oxides, and in combining metals in an alloying process. The disclosed embodiment of the apparatus includes a furnace having a hearth, a pair of tubular residence chambers each extending upwardly from the hearth, a first plasma torch mounted at the upper end of each residence chamber, and a second plasma torch mounted for heating the material on the hearth. The powdered or granular material is fed into the upper end of each residence chamber, such that the material is at least partially melted from the heat of the first torch while falling through the residence chamber, and the material is further heated and completely melted on the hearth by the second torch.

Abstract: A plasma arc heating apparatus is disclosed which is adapted for heating large quantities of air for commercial and industrial uses, and which comprises a housing including an elongate heating chamber, a tubular front electrode mounted at one end of the housing, and a plasma arc torch mounted at the other end of the housing. The torch is mounted for movement toward and away from the front electrode and a power supply system is provided for establishing an arc which extends from a rear electrode in the torch through the heating chamber and to the front electrode at the opposite end of the housing. Structure are also provided for introducing a gas to be heated into the chamber between the torch and the front electrode, and such that the gas is heated by the arc and flows outwardly through the front electrode.

Abstract: A plasma arc torch is disclosed which comprises front and rear coaxially aligned electrodes, and vortex generator for generating a vortical flow of gas, such as air, between the two electrodes. A power supply system is operatively connected to the two electrodes for generating an arc which is adapted to extend axially from the rear electrode through the vortical flow of gas and to an attachment point located on the front electrode. The bore of the front electrode includes a cup-shaped outer end portion which defines a forwardly facing radial shoulder. By proper coordination of the power and gas delivery systems, the arc may be made to attach to the radial shoulder of the front electrode, and such that the erosion of the front electrode occurs along an axial direction rather than a radial direction.

Abstract: A method is disclosed in which a plasma arc torch is used to vitrify and remediate a site containing contaminated soils, resulting from a hazardous material deposit or spill, or contaminated buried objects. The contaminated earthen material or subterranean deposit is pyrolyzed, melted or solidified by the plasma torch which is energized at the bottom of a cased, vertical borehole, and then gradually raised to the surface. An array of boreholes, appropriately spaced, will remediate an entire mass of contaminated material. Similarly, burled objects such as metal drums containing contaminants and underground storage tanks may be selectively remediated at their specific buried depth. Similar use is made of the plasma torch in a second embodiment with the additional step of processing at selected underground locations in the borehole array to create a sealed horizontal layer, vertical cutoff walls or a sealed basin as a barrier against further leaching of contaminants into surrounding soil and groundwater.

Abstract: The process or the present invention serves to remediate and reduce the volume of waste materials in a landfill site and increases the useful life of the treated landfill. The process steps involve drilling a series of holes into the waste material mass at proper spacing, inserting and operating a plasma arc torch in each drilled hole to pyrolize, remediate and vitrify the waste materials and allowing the melted materials to cool and harden. During the process, a gaseous by-product is produced and collected in a hood which is attached to scrubbing and chemical cleaning apparatus. The resultant gases are commercially useful as fuel gas and the vitrified residue is significantly smaller in volume than the original waste material volume, thus substantially extending the useful life of the landfill site and ultimately providing a firm foundation for construction.