Abstract: The invention provides an improved near net-shape VPS formed multilayered combustion system component having an inner surface consisting of a smooth protective thermal barrier coating, and an outer layer of superalloy capable of withstanding temperatures in excess of 700° C. The invention also includes the method of forming such components by first vacuum plasma spraying a suitable mold with a ceramic top coat, followed by a bond coat and followed by a thick structural layer of superalloy. The mold is then separated from the multilayered structure which results in the desired near net-shape component. Combustor liners and transition ducts of gas turbine engines can be advantageously formed in this manner.

Abstract: A process and an apparatus are disclosed for improved recovery of metal from dross, wherein a dross treating furnace is provided with a refractory wall or lining with good capacity to store and conduct heat. This furnace is preheated to a desired temperature by injection of oxygen to burn non-recoverable metal remaining in the residue after tapping of the recoverable metal contained in the dross. When dross is treated in such preheated furnace, the heat emanating by conduction from the furnace wall is sufficient to melt and separate the recoverable metal contained in the dross, without addition of an external heat source, such as fuel or gas burners, plasma torches or electric arcs.

Abstract: A compact furnace having three main chambers. In the first chamber, the water and the organic compounds are dissociated and vaporized and the metals and ceramics are vitrified and transformed into molten slag. A plasma torch or an induction coil can be used to provide the energy required for this operation. In the second chamber, the dissociated and vaporized compounds are burned in air or oxygen using a plasma torch to supplement the energy requirements. The third chamber receives and stores the vitrified slag. The furnace has a lightweight, multi-layered, air-cooled chamber wall construction that incorporates layers of advanced materials to provide both structural integrity at elevated operating temperatures and includes a dynamic cooling control element.

Abstract: The invention provides an improved near net-shape VPS formed multilayered combustion system component having an inner surface consisting of a smooth protective thermal barrier coating, and an outer layer of superalloy capable of withstanding temperatures in excess of 700.degree. C. The invention also includes the method of forming such components by first vacuum plasma spraying a suitable mold with a ceramic top coat, followed by a bond coat and followed by a thick structural layer of superalloy. The mold is then separated from the multilayered structure which results in the desired near net-shape component. Combustor liners and transition ducts of gas turbine engines can be advantageously formed in this manner.

Abstract: The invention provides an improved thermal barrier coating system for a hot section component. The thermal barrier coating has a metallic bond coat and a ceramic top coat made of two constituents. The top coat is formed so that there is provided a graded interface between the monolithic layers of the two top coat constituents. This allows an increase in overall thickness of the thermal barrier coating which provides a higher thermal insulation for the component being protected.

Abstract: This invention discloses a method and an apparatus for gasification and vitrification of ashes, such as produced in a hog-fuel fired boiler, by means of a plasma arc. The ashes are introduced into a shaft furnace where two or three tiltable electrodes are located. The plasma arc is ignited between these electrodes which are then tilted from a horizontal to an essentially vertical position whereby the arc is lengthened and then broken into separate arcs, one between each electrode and the slag accumulated at the bottom of the furnace. This plasma arc helps to burn off the organics in the ashes, producing combustion gases that can be used as a source of energy for the boiler, and to keep the slag in molten state, which allows its periodic removal through a tap hole.

Abstract: A metal or an alloy thereof, or a ceramic that has a liquid phase is introduced in the form of a rod or a wire or as a liquid stream into the apex formed by a plurality of converging plasma jets. Atomization takes place and upon controlled cooling good quality spheroidal powders are obtained whose size varies generally between about 10 and 300 .mu.m.

Abstract: The invention overcomes the problem of paper edge overdrying during the paper drying process on paper machine drying cylinders. It comprises applying a thin ceramic coating onto the circumferential exterior surface of the cylinder near the cylinder edges, thereby forming a thermal barrier coating which decreases paper drying rate at said edges and reduces or eliminates paper edge overdrying.

Abstract: A process is disclosed to synthesize fullerenes in a plasma reactor. It comprises introducing various amounts of carbon halides as the plasma forming gas in a plasma torch capable of producing a high enough temperature flame to dissociate the carbon bearing molecules into carbon and halogen atoms, hence forming a carbon cloud which condenses into a soot containing fullerenes. Also hydrocarbons can be introduced in the torch as the plasma forming gas and reacted with carbon halides or halogens injected therewith or directly into the plasma flame at the exit of the torch. Moreover, an inert gas, such as helium, may also be used as the plasma forming gas. The process can use a high enthalpy non-transferred d.c. plasma torch or an induction plasma torch as the plasma generating device.

Abstract: A reactive spray forming process comprises generating a molten spray of metal, and reacting such molten spray of metal in flight with a surrounding hot metal halide gas to form a desirable alloy, intermetallic or composite product. The molten spray of metal may be directed towards a cooled substrate and the alloy, intermetallic or composite product collected and solidified on the substrate.