Abstract:
Material, such as, for example, sealed double bags of asbestos (24) containing waste or ash from infectious waste or toxic material or radioactive waste, is transferred into a glass melt of a furnace (10). Gas bubbles released into the melt form a gas curtain (12) which causes enhanced mixing of the material to accelerate the dissolution of the components of the added material (7). The presence of the gas bubbles (12) reduces the cross section of the molten glass (32) through which current passes, which in turn increases the electrical resistance of the glass melt (32) or power density at constant current. A highly oxidizing hot region is produced under the location where the material is introduced into the furnace (10). Drawn off glass is shaped and quenched into at least two sizes of approximate spheres (23). The spheres (23) are cooled sufficiently fast to be thermally tempered and have a surface compressive strength level above 5000 psi.
Abstract:
The invention concerns the structural design of stirrers for molten glass. The object of the invention is to develop, with a minimum amount of material, a stirrer for homogenizing molten glass in high temperature ranges, the stirrer consisting exclusively of noble metals and/or noble metal alloys. The object is achieved in that the stirrer consists of a special, highly stable framework construction, and the structural components of dispersion-hardened platinum or a dispersion-hardened platinum/rhodium alloy are thin-walled. Disposed in a hollow stirrer shaft are a plurality of different stirrer shaft strengtheners, some of which terminate at the stirrer shaft wall or project therethrough and, as external stirrer extensions, are undetachably connected to the stirrer shaft. The stirrer shaft strengtheners and stirrer extensions are disposed in any configurations and various combinations over the entire height of the stirrer.
Abstract:
A method and apparatus for recycling scrap mineral fibers (42) having an organic binder coating in a highly stirred glass melter (16) wherein the organic binder coating is decomposed by applying heat. Carbon from the organic binder coating is oxidized on the surface of the glass melt (17). After oxidizing the carbon, the glass fibers are dispersed into the melt. Residual carbon may be oxidized after inclusion in the melt. Purified glass suitable for forming glass fibers is further processed by conventional glass fiber forming equipment. The method may also include the step of pre-processing the glass fiber scrap by shredding or pulverizing to facilitate feeding the glass fiber scrap to the highly stirred glass melt. The apparatus according to the present invention is preferably a stirred melter (16) having electrical joule effect heating. An impeller (22) in the glass melt stirs the melt at a high rate of speed to provide a draw down effect pulling fibers into melt.
Abstract:
Organic or anorganic chemical waste material is encapsulated in ordinary silica-glass by mixing the two in liquid condition under pressure in a container (1, 24, 39), cooling the mixture and solidifying in shapes like cylinders, rods or pellets. The container may be a rotary mixing cylinder (1), a stationary extruder (23) or, for anorganic material, a widened portion (39) of a glass supply conduit (38) wherein the mixture is vibrated (43).
Abstract:
The invention concerns a method of homogenizing molten glass and a device for carrying out this method. The object of the invention is to develop a method for uniformly homogenizing the glass at high temperatures using a homogenizing device composed of components which can be replaced according to the modular principle using the minimum amount of material. The method is characterized in that the glass is homogenized as a result of constantly changing directions of flow such that layers of glass resting above and below the stirrer cell cover tiles are forcibly mixed. The device according to the invention comprises a stirrer which rotates in a stirrer cell and has stirrer extensions which take the form of stirrer fingers and laminar and/or helical stirrer extensions and are disposed at the same and/or different levels.
Abstract:
A glass melter (30) having a mixing impeller (34) for converting a feed stream (38) supplied to a vessel (32) into a vitrified glass melt (50). Heating means such as electrodes (36) or a gas burner (58) are used to heat the glass melt (50). Electrode (36) arrangements are proposed for minimizing current flow through the impeller (34). Current flow through a special continuous circular impeller or conical pump (70) is disclosed. A cylindrical vessel (98), triangular vessel (94), square vessel (32), and hexagonal vessel (96) are disclosed. Methods of processing particular waste streams are disclosed including coated mineral fibers, fly ash, radioactive material, chemical waste and the like.