Systems and methods to improve an industrial heater are disclosed. The heater comprises a horizontal cylinder oriented parallel to the ground and may encase an interior recess running the length of the heater. The heater may be divided into a plurality of sections or zones. One or more mid-rings may support the structure of the heater, and may be disposed at the intersections of adjacent sections or zones. A plurality of interior boards and/or insulation layers may line the interior façade, and may be configured to overlap each other and/or interlock together. The interlocking structure may be absent of any gap or space to prevent heat loss from the interior recess. One or more heat strips may be configured in a sinusoidal pattern. The strips may be mirrored on the opposite side of the interior recess, and may be configured to elongate in the direction opposite of gravity.

It is an object of the present invention to allow a furnace core tube used for a heat treatment apparatus of a porous glass base material to be used for a long period of time.

A heat treatment apparatus includes: a furnace core tube made of silica glass; a heater provided adjacent to the furnace core tube, the heater heating a heating region; and a moving mechanism supporting a porous glass base material and relatively moving the porous glass base material with respect to the heater in the furnace core tube in a state where the heating region is heated by the heater to make the porous glass base material pass through the heating region. The heat treatment apparatus includes a thin-walled part provided in a region adjacent to a portion located in the heating region in the furnace core tube, the thin-walled part having a thickness of glass less than that of the portion located in the heating region.

It is an object of the present invention to allow a furnace core tube used for a heat treatment apparatus of a porous glass base material to be used for a long period of time.

A heat treatment apparatus includes: a furnace core tube made of silica glass; a heater provided adjacent to the furnace core tube, the heater heating a heating region; and a moving mechanism supporting a porous glass base material and relatively moving the porous glass base material with respect to the heater in the furnace core tube in a state where the heating region is heated by the heater to make the porous glass base material pass through the heating region. The heat treatment apparatus includes a thin-walled part provided in a region adjacent to a portion located in the heating region in the furnace core tube, the thin-walled part having a thickness of glass less than that of the portion located in the heating region.

According to a graphite production method for producing graphite of higher quality, a maximum temperature inside a heating furnace of not less than 2900° C. causes an electrical discharge between a heater and a graphite container, and thus leads to a failure to efficiently convert electrical power into heat of the electrical heater. A graphite production method for producing graphite of higher quality is provided. Graphite having a higher heat diffusivity is obtained by carrying out a graphitization step such that a distance between a graphite container and the heater falls within a particular range of length, an atmosphere of a gas inside the heating furnace is set to contain a helium gas, and heating is carried out so that a maximum temperature inside the heating furnace is not less than 2900° C.

A sintering furnace (1) for sintering dental workpieces (2), wherein the sintering furnace (1) has a heating element (3) with a receiving space (4) for receiving the workpiece (2) during sintering. The receiving space (4) is a portion of an interior space (5) within the heating element (3), and the heating element (3) comprises or consists of silicon carbide, wherein the heating element (3) is designed, at least in parts, as a slotted tube, and the slot (6) in the tube forming the heating element (3) has a helical configuration in a heating region (7), in which the heating element (3) encloses the receiving space (4).

A sintering furnace (1) for sintering dental workpieces (2), wherein the sintering furnace (1) has a heating element (3) with a receiving space (4) for receiving the workpiece (2) during sintering. The receiving space (4) is a portion of an interior space (5) within the heating element (3), and the heating element (3) comprises or consists of silicon carbide, wherein the heating element (3) is designed, at least in parts, as a slotted tube, and the slot (6) in the tube forming the heating element (3) has a helical configuration in a heating region (7), in which the heating element (3) encloses the receiving space (4).

The invention relates to a dental furnace, in particular a high-temperature dental furnace for oxide ceramics such as zirconium dioxide having sintering temperatures of between 1300 and 1850° C., comprising a heating element (10) which is intended to give off heating energy to the firing chamber. It is provided that the heating element (10) comprises at least two heating element sections (48, 50) adjoining one another at a transition area (34) which is not current-carrying and/or which extends away laterally, that the transition area (34) is supported on a position, in particular on the free end, spaced apart from the electrical connections (16, 18) on the dental furnace and carries at least the two adjoining parts of heating element sections (48, 50).

The invention relates to a dental furnace, in particular a high-temperature dental furnace for oxide ceramics such as zirconium dioxide having sintering temperatures of between 1300 and 1850° C., comprising a heating element (10) which is intended to give off heating energy to the firing chamber. It is provided that the heating element (10) comprises at least two heating element sections (48, 50) adjoining one another at a transition area (34) which is not current-carrying and/or which extends away laterally, that the transition area (34) is supported on a position, in particular on the free end, spaced apart from the electrical connections (16, 18) on the dental furnace and carries at least the two adjoining parts of heating element sections (48, 50).

A process chamber includes one or more vertical walls at least partially defining a chamber portion of the process chamber, and multiple zones located about a periphery of the one or more vertical walls, wherein one or more of the multiple zones extends from a top to a bottom of the one or more vertical walls. The process chamber further includes a plurality of temperature control devices, each thermally coupled to the one or more vertical walls in one of the multiple zones, and a controller coupled to the plurality of temperature control devices and configured to set temperatures of one or more of the plurality of temperature control devices to obtain temperature uniformity within 2% across a substrate located in the chamber portion.

A process chamber includes one or more vertical walls at least partially defining a chamber portion of the process chamber, and multiple zones located about a periphery of the one or more vertical walls, wherein one or more of the multiple zones extends from a top to a bottom of the one or more vertical walls. The process chamber further includes a plurality of temperature control devices, each thermally coupled to the one or more vertical walls in one of the multiple zones, and a controller coupled to the plurality of temperature control devices and configured to set temperatures of one or more of the plurality of temperature control devices to obtain temperature uniformity within 2% across a substrate located in the chamber portion.