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Radiant
SiC heating Elements
General Description
The silicon carbide heating element is a kind of non- metal high temperature electric heating element. It is made of selected super quality green silicon carbide as main material, which is made into blank, silicided under high temperature and re – crystallized. Compared with metal electric heating element, this kind of element is characterized by high-applied temperature, anti – oxidization, anti – corrosion, long service life, little deformation, easy installation and maintenance. Therefore, it is widely used in various high temperature electric furnaces and other electric heating devices, such as in the industries of magnet, ceramics, powder metallurgy, glass, metallurgy and machinery, etc.
We adopt new production process of cold ends so that our SiC heating elements and carbide heaters have more excellent specific rate of heat zone resistance and cold end resistance, saving energy, long life, avoiding over – temperature of cold ends to damage the furnace body. The commercial name of our SiC heating elements is RADIANT SILICA HEATING ELEMENTS.
Specifications and types of Radiant Silca heating elements
ED (rod) type elements
Type : ED outer diameter : OD, mm
Hot zone length : HZ, mm
Coldzone length: CZ,mm
Overall length : OL, mm
Examples:
ED Type , OD =54mm, HZ=1575mm,
CZ=419mm,OL=2413mm, Resistance 0.90 ohm
Specify as: Radiant Silca ED, 54/1575/2413/0.90ohm
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DB (dumbbell) type elements
Type :DB Diameter : D1/D2, mm
Hot zone length: HZ, mm
Cold zone length: CZ,mm
Overall length: OL, mm
DB , D1/D2 = 18/28mm, HZ=300mm, CZ=350mm, OL =1000mm, Resistance 1.70 ohm
Specify as: Radiant Silica DB, 18/300/350/1.7ohm
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U type elements
Type : U Outer diameter: OD, mm
Hot zone length: HZ, mm
Coldzone length: CZ,mm
Overall length :OL, mm
Shank Spacing: A, mm
Bridge:D, mm
Examples:
U Type, OD=20mm, HZ=300mm,
CZ=400mm, OL=700mm, A = 60mm, Resistance 2.24ohm
Specify as:
Radiant Silica U, 20/300/400/60/2.24ohm
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W (three phase) type elements
Type :W Outer diameter :OD, mm
Hot zone length : HZ , mm
Cold end length:CZ, mm
Overall length: OL, mm
Shank Spacing: A, mm
Bridge: D, mm
Examples:
W Type , OD=20mm, HZ= 250mm, CZ=350mm, OL= 625mm, A=52mm, Resistance 0.90ohm
Specify as: Radiant Silca W, 20/250/350/52/0.90ohm
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SC ( single spiral ) type elements
Type : SC Outer diameter : OD , mm
Hot zone length: HZ , mm, Cold end length : CZ, mm
Overall length: OL, mm
Examples:
SC Type , OD=25mm, HZ=300mm, CZ=200mm, OL = 700mm, Resistance 1.59 ohm
Specify as:
Radiant Silca SC, 25/300/700/1.59Ohm |
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SCR
SC ( double spiral ) type elements
Type : SCR Outer diameter : OD, mm
Hot zone length: HZ, mm
Cold end length: CZ, mm
Overall length: OL, mm
Examples :
SCR Type , OD=31.7mm, HZ= 305mm,. CZ=241 mm, OL=546mm, Resistacne 4.46 ohm
Specify as :
Radiant Silca SCR , 31.7/305/546/4.46ohm |
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UX ( slot ) type elements
Type : UX Outer diameter :OD, mm
Hot zone length: HZ , mm
Cold end length : CZ , mm
Overall length: OL, mm
Examples :
UX Type , OD=30MM, HZ=400mm, CZ=300mm, OL=700mm , Resistance 2.76 ohm
Specify as :
Radiant Silca UX , 30/400/700/2.76 ohm |
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Physical properties of elements
The linear expansion coefficient, heat conductivity and specific heat of element will change along with temperature change. And the relational data are the follows:
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Chemical properties of elements
- Antioxidant property of elements
The element start to being oxidized when heated to 800 o Celsius in air, and a SiO2 protective film will be generated on the surface of hot zone, when temperature gets to 1000 - 1300 o Celsius; cristobalite will be crystallized at 1300 o Celsius; the protective film gets to a certain thickness when the temperature gets to 1500 o Celsius, which make the oxidation speed to stabilize very slowly. If continue to heat over 1627 o Celsius, the protective film will be damaged and oxidation speed will be more rapid evidently and make the element damaged earlier.
Though the element will be oxidized very slowly in course of application, it will also increase the resistance, following long time application, this phenomenon is called aging. In order to lower the aging speed, we use special technology to coat a protective film on the surface of hot zone in the course of production, which enhance the Antioxidant property of element and lengthen the service life.
- The effects of alkali and alkaline metal oxide to elements
The alkali & alkaline metal oxide will react with SiC at about 1300 oCelsius and generate silicate, which causes alkali – chemical corrosion, and can influence the glowing of element .
- The effects to elements from melting metal
Some metals, such as cobalt, nickel, chrome and so on, can corrode the element in high temperature melting state and affect the service life of element.
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Electric properties of elements
SiC heating elements has rather higher specific resistance. When it is heated in air and the surface temperature of the hot zone reaches 1050 o Celsius, its resistance rate is 600 – 1400 ohm mm2/m. Its resistance value changes along with the temperature rising. From room – temperature to 800 o Celsius is negative value, over 800 o Celsius is positive value nature curve.
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Accessories of Elements
The accessories of SiC elements include aluminum braid, connecting straps and clamps, the kinds of clamps are ‘H’ type, ‘G’ type and ’C’ type.
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Connecting Strips
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Clamps |
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Copyright: Radiant Technologies |
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