Abstract: The present invention relates to the foundry industry and solves the problem of extended service life of valve closure gate assemblies for foundry ladles. The valve closure gate assembly of the present invention comprises two mutually slidable heat-resistant gates furnished with a protecting layer of an oxide refractory material and having flow-through rings made from an oxide refractory material disposed in the openings of the gates. The respective upper and lower surfaces of the rings are coated with a layer of refractory material.

Abstract: A plasma generator arrangement for applying material to an electrical conductive substrate and method for utilizing the same. The generator arrangement comprises a generator for creating and extending towards the substrate a plasma stream containing the material. The plasma generator arrangement further including structure for selectively controlling the electrical potential of the substrate relative to the generator anode so as to vary with time the extension of the plasma stream past the generator.

Abstract: Method of and apparatus for stabilizing a plasma stream by the use of two different stabilization liquids. The plasma arc is stabilized in the discharge chamber by a whirl of a first stabilization liquid containing at least one element chosen from the group consisting of carbon and nitrogen, and the plasma arc is stabilized in the stabilization channel by a second stabilization liquid differing in its boiling point from the first stabilization liquid. Between the discharge chamber of the burner and the stabilization channel there is provided a transition space from which there lead slit-like outlets for the stabilization liquids. In the transition space there may be placed an orifice plate dividing said space into two sub-spaces. From the stabilization channel upstream of the front nozzle of the burner there may be provided an outlet for the second stabilization liquid, which is disposed in the stabilization channel.

Abstract: Method of and apparatus for stabilizing a plasma stream by the use of two different stabilization liquids. The plasma arc is stabilized in the discharge chamber by a whirl of a first stabilization liquid containing at least one element chosen from the group consisting of carbon and nitrogen, and the plasma arc is stabilized in the stabilization channel by a second stabilization liquid differing in its boiling point from the first stabilization liquid. Between the discharge chamber of the burner and the stabilization channel there is provided a transition space from which there lead outlets for the stabilization liquids. In the transition space there may be place an orifice plate dividing said space into two sub-spaces. From the stabilization channel upstream of the front nozzle of the burner there may be provided an outlet for the second stabilization liquid, which is disposed in the stabilization channel.

Abstract: The present invention relates to a method of producing self-supporting constructional elements by plasma-spraying onto a removable core.Recently, there is in widespread use the method of producing constructional elements, especially of heat-resistant elements of rotary shape, by plasma-spraying of ceramic oxides onto a removable core. Existing problems in the art are caused by the slow removal of an intermediate layer, which separates the deposited constructional element material from the core, in suitable solvents, and the necessary neutralization of the produced constructional element.These disadvantages are overcome by the method of the present invention characterized in that a core is preheated to a temperature in the range of from about 200.degree. C. to about 650.degree. C., a metallic or non-metallic intermediate layer having a thickness of about 0.1 to about 2 millimeters is deposited on the core by plasma-spraying.

Abstract: Spray-coating materials having a high heat-resistance and thermal conductivity for the surface protection of materials. The spray-coating material consists of 8-35 wt. % magnesium oxide MgO or calcium oxide CaO, 2-10 wt. % of beryllium oxide BeO and 55-90 wt. % of aluminum oxide Al.sub.2 O.sub.3, zirconium dioxide ZrO.sub.2, silicon dioxide SiO.sub.2, chromic oxide Cr.sub.2 O.sub.3 and titanium dioxide TiO.sub.2. The spray-coating material of the invention can be employed to advantage, for example, in the chemical industry and in metallurgy.

Abstract: There is disclosed a material for hot or plasma spraying, especially a material based on oxide ceramics, and a process for the production thereof. The composition of the invention is a mixture of powdered oxides containing at least two fundamental oxides with high melting point, and at least one glass-forming oxide the melting point of which is lower. The invention also includes a process for the production of such composition by the melting and agglomeration of individual components in the oxidizing medium of a plasma stream, including the special treatment of the starting components.

Abstract: Process of radial stabilization and homogenization of a plasma stream and a liquid stabilized plasma burner for the realization of such process. The arc is stabilized by its passage through several orifice plates, stabilized by a whirl or eddy of cooling liquid, then passes through a nozzle and is bent toward the peripheral surface of a rotatable anode lying out of the main outlet plasma stream issuing from the nozzle. The liquid stabilized burner has a rod cathode placed in the arc chamber, the cathode being progressively fed into the arc chamber to from an arc therewithin.

Abstract: A method of bonding at least two types of refractory ceramic materials, a first material being, for example, fireclay and a second material being, for example, alumina, to each other in order to enhance both the abrasion and corrosion resistances of heat resistant plates for valve closures of foundry ladles. The second, thermally more resistive material, which is applied to the first material in the form of relatively small particles, is preheated on at least the outer surface layers of the particles, the entire volume of the particles usually being preheated or even molten. The bonding of the two preheated materials occurs in such a way that minute particles up to drops of the second, thermally more resistive material are thrown at high speed (with high kinetic energy) onto the preheated surface of the first material. The source of such a relatively high kinetic energy can be constituted by either an explosion or a plasma beam ejected at a high outlet velocity out of the mouth of a plasma torch.