Disclosed is a heating element for a dental furnace including a tube element for accommodating a heating coil inside the tube element. At least one closing element may be connected to at least one open end of the tube element, wherein electrical connectors may be led through the closing element and fused with the element. The tube element may be made from a ceramic material, such as oxide ceramics, that may be connected to the connector via a plurality of intermediate glasses/transition glasses and glass solder to compensate for different heat expansion coefficients such that up to 500 C. gas escaping from the tube element may not enter due to a thermal action, providing that operational safety of the heating element is ensured. Further, disclosed is a dental furnace including such a heating element.

A joining apparatus is an apparatus for performing joining of a joining target object including multiple members stacked on each other and a thermosetting adhesive arranged on joining target portions of the multiple members. The joining apparatus includes a first electrode; a second electrode; a pressurization mechanism configured to cause the first and second electrodes to pressure-contact the surface of the joining target object in the vicinity of the joining target portions; a power source configured to distribute power to between the first electrode and the second electrode; and a control unit configured to distribute the power to between both electrodes by the power source in a state in which the first electrode and the second electrode pressure-contact the surface by the pressurization mechanism, thereby performing joining of the joining target object by curing of the thermosetting adhesive by resistance heating generated at the joining target object.

A joining apparatus is an apparatus for performing joining of a joining target object including multiple members stacked on each other and a thermosetting adhesive arranged on joining target portions of the multiple members. The joining apparatus includes a first electrode; a second electrode; a pressurization mechanism configured to cause the first and second electrodes to pressure-contact the surface of the joining target object in the vicinity of the joining target portions; a power source configured to distribute power to between the first electrode and the second electrode; and a control unit configured to distribute the power to between both electrodes by the power source in a state in which the first electrode and the second electrode pressure-contact the surface by the pressurization mechanism, thereby performing joining of the joining target object by curing of the thermosetting adhesive by resistance heating generated at the joining target object.

A system for positioning an optical preform in a furnace is provided that includes an upper muffle and a downfeed handle assembly with a tube defining a first end and a second end, the second end extending into the upper muffle. A handle is disposed within the tube. A second end of the handle extends into the upper muffle and a seal assembly is positioned around both the tube and the handle. The first end of the handle extends through the seal assembly and a drive assembly is coupled with the downfeed handle.

A system for positioning an optical preform in a furnace is provided that includes an upper muffle and a downfeed handle assembly with a tube defining a first end and a second end, the second end extending into the upper muffle. A handle is disposed within the tube. A second end of the handle extends into the upper muffle and a seal assembly is positioned around both the tube and the handle. The first end of the handle extends through the seal assembly and a drive assembly is coupled with the downfeed handle.

A superheater may comprise a heating element that includes carbon nanotubes, wherein the heating element is encapsulated within a thermally insulating material on a first surface of the heating element and an inert material on a second surface and sides of the heating element, a positive electrical connection and a negative electrical connection, wherein the positive electrical connection and the negative electrical connection extend through the inert material, and wherein the positive electrical connection and the negative electrical connection are configured to connect the carbon nanotubes to an electric power source.

A superheater may comprise a heating element that includes carbon nanotubes, wherein the heating element is encapsulated within a thermally insulating material on a first surface of the heating element and an inert material on a second surface and sides of the heating element, a positive electrical connection and a negative electrical connection, wherein the positive electrical connection and the negative electrical connection extend through the inert material, and wherein the positive electrical connection and the negative electrical connection are configured to connect the carbon nanotubes to an electric power source.

Methods and apparatus to thermally destruct volatile organic compounds are disclosed. An example thermal oxidizer for a furnace includes: an oxidation chamber comprising an inlet configured to receive exhaust gases from a furnace and an outlet configured to output resultant gases; and a plurality of heating elements within the oxidation chamber configured to heat the exhaust gases to oxidize one or more components of the exhaust gases between the inlet and the outlet to result in the resultant gases, the plurality of heating elements comprising resistive heating elements forming coils having respective axes, the plurality of heating elements being oriented within the oxidation chamber such that the axes of the coils are transverse to an exhaust gas flow direction from the inlet to the outlet of the oxidation chamber.

The invention relates to a dental furnace, in particular a high-temperature dental furnace for oxide ceramics such as zirconium dioxide with sintering temperatures of between 1350 C. and 1650 C., having heating elements (14, 16) which are intended to give off heating energy to a firing chamber (12) in the dental furnace (10). The heating elements (14, 16) are configured as electrical resistance heating elements and supported below the firing chamber (12) each by means of at least one heating element support foot (18). The heating elements (14, 16) extend vertically to the top starting from the heating element support feet (18) and at the top, end in an arch (46), in particular in a semicircular arch or possibly in a pointed arch, without an upper lateral support, in particular not in the region of the arch (46).

A microwave oven is provided including a cooking cavity for receiving food to be cooked, at least one microwave source for generating microwave energy inside the cooking cavity, and a supplemental heating system positioned to heat the food. The supplemental heating system includes at least one IR radiation source for generating IR radiation and a metallic mesh screen placed between the at least one IR radiation source and the cooking cavity for spatially distributing the IR radiation to uniformly project into the cooking cavity and minimizing microwave energy field losses. The metallic mesh screen includes a plurality of hexagonal apertures arranged in a honeycomb pattern. The distance between parallel sides of each one of the hexagonal apertures is Ax and the distance between each hexagonal aperture and each adjacent hexagonal aperture is Bx where Ax is less than or equal to about 3 times Bx.