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CN-115210519-B - High temperature thermal insulation of electrolytic coupling

CN115210519BCN 115210519 BCN115210519 BCN 115210519BCN-115210519-B

Abstract

The invention relates to an insulating element (1) for thermally insulating an inductively heatable high temperature treatment zone (2), wherein the wall of the insulating element (1) comprises a flat material (3) having a resistivity ρ F of 10 ‑5 to 10 ‑1 Ω m, which surrounds a hollow space (4) extending through the insulating element (1) and comprises a fracture (5) having a resistivity ρ U greater than ρ F , wherein the fracture (5) extends from an outer surface (6) of the flat material (3) into the flat material (3) without interrupting the flat material (3) over the entire cross section (8) of the flat material.

Inventors

  • Frank Azelte
  • Bojana Jokanovic

Assignees

  • 西格里碳素欧洲公司

Dates

Publication Date
20260505
Application Date
20210217
Priority Date
20200304

Claims (18)

  1. 1. An insulating element (1) for thermally insulating an inductively heatable high temperature treatment zone (2), wherein the wall of the insulating element (1) comprises a flat material (3) having a resistivity ρ F of 10 -5 to 10 -1 Ω m, surrounding a cavity (4) extending through the insulating element (1) and comprising a fracture (5), in which fracture (5) the resistivity ρ U is greater than ρ F , wherein ρ U is at least 100 Ρ F , wherein the fracture (5) extends from the outer surface (6) of the flat material (3) into the flat material (3) without producing a fracture in the flat material (3) over the entire flat material cross section.
  2. 2. Insulating element (1) according to claim 1, wherein the break (5) is a cut (51) made in the flat material (3).
  3. 3. Insulating element (1) according to claim 1, wherein at least a portion of the fracture (5) does not extend orthogonal to the outer surface (6) and the inner surface (7) of the flat material (3).
  4. 4. Insulating element (1) according to claim 1, wherein the flat material (3) has a degree of thermal conductivity of less than 10 Wm -1 K -1 .
  5. 5. Insulating element (1) according to claim 4, wherein the flat material (3) comprises carbon fibres and/or expanded graphite.
  6. 6. Insulating element (1) according to claim 1, wherein the number of interruptions (5) is greater than or equal to 2.
  7. 7. Insulating element (1) according to claim 6, wherein the number of interruptions (5) is greater than or equal to 3.
  8. 8. Insulating element (1) according to claim 7, wherein the number of interruptions (5) is greater than or equal to 4.
  9. 9. Insulating element (1) according to claim 8, wherein the number of interruptions (5) is greater than or equal to 6.
  10. 10. Insulating element (1) according to claim 1, wherein the shape of the insulating element can be substantially a hollow cylinder, wherein the length, shape and orientation of the interruptions (5) at the outer surface of the flat material (3) are selected such that the following conditions apply: L u > a L t Wherein, the L t is the length of the shortest path around the flat material (3) that extends along the outer surface of the flat material (3), across the fracture (5), and into a central cutting plane that divides the flat material (3) into two halves of equal flat material volumes, orthogonal to the longitudinal axis of the hollow cylinder, L u is the length of the shortest path around the flat material (3) which extends in each case from one break (5) to the other break (5) in the central cutting plane, but does not pass through the break (5), but bypasses the break, and A is 2.
  11. 11. Insulating element (1) according to claim 10, wherein a is 5.
  12. 12. Insulating element (1) according to claim 1, wherein the break (5) is spaced apart from both edges (9, 10) of the flat material (3).
  13. 13. Insulating element (1) according to claim 6, wherein at least two interruptions (5) are inclined in the same direction with respect to the outer surface of the flat material (3).
  14. 14. Insulating element (1) according to claim 1, wherein the flat material (3) is a circumferentially continuous flat material (3) comprising carbon fibers.
  15. 15. Insulating element (1) according to claim 1, wherein the flat material (3) is formed by a set of flat material elements (11), and wherein at least one joint region (12) breaking the flat material (3) over the entire flat material cross section is additionally provided between the flat material elements (11).
  16. 16. A set of insulating element portions for forming an insulating element (1), wherein the insulating element (1) comprises the insulating element portions, wherein at least one of the insulating element portions comprises a flat material (3) having a resistivity ρ F of 10 -5 ～10 -1 Ω m and comprising a fracture (5), in which fracture (5) the resistivity ρ U is greater than ρ F , wherein ρ U is at least 100 Ρ F , wherein the fracture (5) extends from the outer surface (6) of the flat material (3) into the flat material (3) without producing a fracture in the flat material (3) over the entire flat material cross section (8).
  17. 17. Method for producing a flat material (3), which flat material (3) can be used for insulating an inductively heated high-temperature treatment zone (2), wherein the electrical resistivity ρ F of the flat material (3) is in the range of 10 -5 ～10 -1 Ω m, which flat material (3) is cut into the flat material (3) from the main surface of the flat material (3) without cutting through the entire flat material (3) in order to form a fracture (5), wherein in the fracture (5) the electrical resistivity ρ U is greater than ρ F , wherein ρ U is at least 100 ρ F 。
  18. 18. Use of an insulating element according to any one of claims 1 to 15 or an insulating element formed partly of a set of insulating elements according to claim 16 for thermally insulating an inductively heated high temperature processing zone (2).

Description

High temperature thermal insulation of electrolytic coupling Technical Field The invention relates to an insulating element for thermally insulating an inductively heatable high temperature treatment zone, to a set of insulating element parts for forming an insulating element comprising insulating element parts, to a method for producing a flat material which can be used for insulating an inductively heatable high temperature treatment zone, and to the use of an insulating element for thermally insulating an inductively heatable high temperature treatment zone. Background High temperature processes, for example, conducted in an inert atmosphere above 800 ℃, place high thermal and mechanical demands on the insulating materials used. Carbonized and optionally graphitized felts are commonly used as the material of the insulator separating the heating chamber from the cooled outer walls of the high temperature furnace. EP 1 852 B1 discloses a method for producing a high temperature resistant insulator, wherein a plurality of curved segments are made of, inter alia, an expanded graphite based material, which is compressed to a density between 0.02 and 0.3g/cm 3 to form a hollow cylinder assembly. In this case, the individual segments are held together by a carbonizable binder comprising planar anisotropic graphite particles. Further, a graphite foil is arranged on the inner surface of the hollow cylindrical insulator. WO 2011/106580 A2 discloses an insulator for a reactor made of carbon fiber material, the insulator being assembled from a plurality of individual plate-like components. The individual components may be coupled by a "tongue and groove" male connector using additional connecting elements. The patent document CN202610393U describes a thermal insulation device for producing sapphire crystals, in which a circumferential graphite felt is formed by combining three fan-shaped soft felts. CN102748951a describes a thermally insulating material in the form of a unit formed by a plurality of strips. The slats include mortises that can be joined to form a circular arc thermally insulated cylinder. The construction of the unit from strips is intended to allow local replacement and repair of damaged components. It is intended to make the thermal insulation property excellent and to last for the whole service life. The insulating cylinder can be stored and transported conveniently. The insulating cylinder is intended to reduce the operating costs considerably. DE 68920856T 2 describes a tubular thermal insulator consisting of (a) a multi-layer carbon fiber mat wound in a spiral, comprising carbonized resin, and (b) carbonized film and/or mesh and resin present between mat layers, which form a continuously laminated tubular element, wherein the mat layers are integrally bonded to each other by the carbonized resin present between the mat layers. The thermal insulator is intended to have a high density and to provide excellent thermal insulation and surface smoothness. The density of which varies intentionally in the radial direction. The thermal insulator is also intended to be produced at a high level of productivity without performing a complicated process. WO 2013/174898 A1 describes a thermal insulator composed of a material comprising carbon fibers and/or graphitized fibers for lining a high temperature furnace, wherein the thermal insulator is composed of at least two separate parts, wherein the at least two separate parts that are bonded together each comprise at least one connecting element, and the connecting elements of the at least two separate parts that are bonded together are interlockingly engaged with each other to form an undercut. In certain high temperature processing methods, a substrate to be processed, such as a fibrous substrate in the production of glass fibers, is continuously conducted through a high temperature processing zone. For example, the temperature in the high temperature treatment zone may be at least 800 ℃. In order to maintain the temperature within the high temperature treatment zone within a specific narrow high range, power must be continuously supplied to the high temperature treatment zone. This is accomplished by induction heating at high temperature. In this case, an electrical coil disposed around the high temperature treatment zone is inductively coupled with the at least one heating element. The heating element may be a refractory wall surrounding the high temperature treatment zone. The wall may comprise graphite. For some insulating materials, during induction high temperature heating, the furnace seems to directly emit excessive heat, and thus its environment is strongly heated, and additional measures must be taken to emit excessive heat, such as complex ventilation or cooling of the production plant in which the furnace is operated. Disclosure of Invention The object of the present invention is to provide a thermal insulation material which can be used, for exam