Silicon carbide heating elements
A strip-form silicon carbide furnace heating element is provided having a higher radiating surface area to volume ratio than a conventional tubular element.
1. A furnace heating element comprising a heating section comprising an extruded silicon carbide strip having a cross sectional aspect ratio greater than 3:1, wherein heating section comprises a recrystallised self-bonded silicon carbide material.
2. A furnace heating element comprising a heating section comprising an extruded silicon carbide strip having a cross sectional aspect ratio greater than 3:1, wherein the heating element comprises reaction bonded or reaction sintered silicon carbide.
3. A method of making a furnace heating element comprising a heating section comprising an extruded silicon carbide strip having a cross sectional aspect ratio greater than 3:1, the method, comprising:
extruding a heating section strip preform, and
bending the extruded preform to shape prior to drying or firing.
4. The method as claimed in claim 3 , further comprising
separately forming cold ends, and
joining the separately formed cold ends to the heating section.
5. The method as claimed in claim 3 , further comprising integrally forming cold ends with the heating section.
6. The method as claimed in claim 3 , further comprising recrystallizing the heating section, to form a self-bonded silicon carbide material.
7. The method as claimed in claim 3 , wherein the material of the extruded preform is such that the final product will comprise reaction bonded or reaction sintered silicon carbide.
8. A furnace heating element comprising a heating section comprising an extruded silicon carbide strip having a cross sectional aspect ratio greater than 3:1, wherein the strip is hollow.
9. The furnace heating element as claimed in claim 1 , wherein the strip comprises a planar portion and a portion that is bent out of the plane of the planar portion.
10. The furnace heating element as claimed in claim 1 , in which the strip is generally U-shaped.
11. The furnace heating element as claimed in claim 1 , wherein at least a portion of the strip has a curved cross-section.
12. The furnace heating element as claimed in claim 1 , wherein the cross sectional aspect ratio is greater than 5:1.
13. The furnace heating element as claimed in claim 12 , wherein the cross sectional aspect ratio is greater than 10:1.
14. The furnace heating element as claimed in claim 2 , wherein the strip comprises a planar portion and a portion that is bent out of the plane of the planar portion.
15. The furnace heating element as claimed in claim 2 , in which the strip is generally U-shaped.
16. The furnace heating element as claimed in claim 2 , wherein at least a portion of the strip has a curved cross-section.
17. The furnace heating element as claimed in claim 2 , wherein the cross sectional aspect ratio is greater than 5:1.
18. The furnace heating element as claimed in claim 17 , wherein the cross sectional aspect ratio is greater than 10:1.