Abstract: A plasma arc melter which is equipped with at least two transferred arc plasma torches of opposite polarities is used to melt normal batch materials for producing glass, ceramics, refractories and other such materials and for the recycling, combustion and/or vitrifying incineration of waste materials. To enhance the stability of the plasma jets, the anode torch is positioned farther above the surface of the materials being processed than the cathode torch and the materials being processed are introduced into the melter so that the materials first pass beneath the cathode torch. An oxidizing gas can be introduced into the zone between the torches in the region of the plasma jets to enhance the combustion process. For waste materials with a high organic content, a plasma arc afterburner can be used to further treat the exhaust gases from the melter.

Abstract: Inorganic fibers which have a silicon extraction of greater than about 0.02 wt % Si/day in physiological saline solutions. The fiber contains SiO.sub.2, MgO, CaO, and at least one of Al.sub.2 O.sub.3, ZrO.sub.2, TiO.sub.2, B.sub.2 O.sub.3, iron oxides, or mixtures thereof. Also disclosed are inorganic fibers which have diameters of less than 3.5 microns and which pass the ASTM E-119 two hour fire test when processed into a fiber blanket having a bulk density in the range of about 1.5 to 3 pcf.

Abstract: A process for the treatment of a continuous or perturbated stream of liquid material, which process consists essentially of passing the said stream of liquid material through a plasma arc coupling zone in which at least two plasma arcs are coupled at the surface of the liquid stream in order to raise both the bulk temperature of the stream and the temperature of the outer surface of the stream of material, thereby to effect a treatment of the stream selected from thermal, chemical, and a mixture of thermal and chemical.

Abstract: A method of melting materials at power densities in excess of 25 KW/ft.sup.2 of area within the metal shell of a melting vessel which method consists essentially of continuously feeding the material to be melted to a plasma arc furnace which is equipped with at least two transferred arc plasma electrodes and with means to rotate at least the portion of the furnace containing the material to be melted, melting the said feedstock material using the at least two transferred arc plasma electrodes whilst rotating at least the rotatable portion of the furnace containing the material to be melted and continuously discharging the material which has been melted from the furnace.Apparatus for melting materials under power densities of greater than 25 KW/ft.sup.2 is also disclosed.

Abstract: An electric furnace for melting batch material and mixing the molten material. Electrodes are used to create what is believed to be electromagnetically stirred active melting areas within the molten material. The molten material is stirred by moving the electrodes and furnace shell with respect to each other while the electrodes are positioned in a corona discharge relationship to the melt. This can be implemented by rotating the electrodes or the shell or by a compound movement caused by moving the electrode support arms toward and away from the center of the vessel in timed relationship to pivotal movement of electrode support arms so as to cause the electrode tips to traverse an arcuate path concentric with the center of the vessel. In a shallow immersion, simple pivoting of the electrode support arms is beneficial. To further decrease the dead area within a furnace vessel utilizing electrodes which are shallowly immersed, the vessel can be made polygonal as opposed to circular in lateral cross section.

Abstract: A refractory fiber composition and method for making refractory fiber from the composition. The refractory fiber composition includes kaolin clay as a source of alumina and silica to which is added zircon.

Abstract: An electric melting furnace is provided for optimally melting and mixing a non-homogeneous material. The melting furnace includes a vessel having its top portion open to the environment. Three electrodes are supported above the furnace. Each of the electrodes includes a tip for insertion into the material contained in the vessel. The vessel further includes an outlet formed in the bottom wall of the vessel to discharge the material after it has been melted and optimally mixed. Each of the three electrode tips has a generally round configuration. During the melting operation, the three electrode tips are laterally spaced from each other and are positioned in the vessel to be surrounded by molten material but above the bottom wall outlet. Optimum melting and then optimum mixing of the material occurs at selected horizontal spacings of the electrode tips and at selected electrode tip immersions in the molten material.

Abstract: A batch material feeder for an electrically heated open-top refractory furnace, particularly a circular furnace, wherein the feeder includes a trough holding batch material and mounted over the furnace top, there being a rotatable agitator within the trough for moving batch material over discharge openings in the trough bottom, so as to deposit the batch material over the top of the molten mass in a manner that provides for a thin uniform layer of batch while assuring proper control of the thickness of the deposited layer.

Abstract: A batch material feeder for an electrically heated opentop refractory furnace, particularly a circular furnace, wherein the feeder includes a trough holding batch material and mounted over the furnace top, there being a rotatable agitator within the trough for moving batch material over discharge openings in the trough bottom, so as to deposit the batch material over the top of the molten mass in a manner that provides for a thin uniform layer of batch while assuring proper control of the thickness of the deposited layer.