Reaction Bonded Double Spiraled Heating Elements

Ultra-spiral Double Spiralled Heating Elements have all terminal connections at one end. These Double Ended Elements are made of high-density Reaction Bonded Silicon Carbide. The typical density of Ultra Spiral Elements is 3.3 Gms. /cc – 3.4 Gms. /cc. Double Spiralled Elements have both the terminal connections on the same end.

The hot zone has a reduced cross-section which is a result of cutting a double spiral slot on the tube. This results in a higher resistance than the cold terminals. The cold end is made by cutting two longitudinal slots along the length of the tube. The cold ends are cemented with a ceramic collar. The flat braided aluminum straps are held in compression with the help of stainless steel clamps. The flat braid is insulated electrically with a clamp with high-temperature insulation. The aluminum is long, and holes are provided for easy connection to the power supply. These are ideal where Furnace access is limited to any one plane.

Double Spiralled heating elements can be mounted in various positions but horizontal and vertical are the most common positions. When mounting the elements horizontally, there is no support needed for the hot end. Precaution must be taken that when mounting the SiC elements horizontally it should not meet the wall of the furnace or kiln. Another important precaution is to give adequate allowance so that the heating elements can expand and contract independently without damaging the furnace walls.

Silcarb Ultra Spiral elements gradually increase in resistance with use. This characteristic is also known as aging. The aging depends on several factors like operating temperature, atmosphere, maintenance techniques, etc. The Ultra-Spiral elements reach temperatures of 1650° C in an inert atmosphere of helium or argon. With reducing atmospheres, the maximum operating temperatures are 1370° C.  Ultra-Spiral Elements operate in most industrial and laboratory Furnaces at temperatures up to 1600° C.

The Ultra-Spiral range of elements is available in different product forms and can be customized to different standard sizes and geometries to suit a variety of heating processes. Contact us for any further details.