Description for  shaped SIC heating element  

 

The shaped SIC heating element   is a resistance type silicon carbide heating elements. The elements are thick walled tubes. They have a central heating section referred to as a hot zone and two terminal sections called cold ends. The cold ends are impregnated with silicon metal to lower their resistance.

 

This causes them to operate at a lower temperature. The extremities of the sic heating elements are metalized with aluminum to provide a low resistance contact surface to which the electrical connections are made with braided aluminum straps. Elements are described by giving the overall length, the heating section length, the diameter and resistance

 

Features for The   SIC heating element

 

High Performance :

 

The  SIC heating elements will give you superior performance due to their high density – approximately 2.4gms/cc. This gives the element very slow aging characteristics and additional strength.

 

Operating Temperatures :

 

The shaped SIC heating elements can be operated at furnace control temperatures up to 14500C in an air atmosphere or inert atmospheres of argon or helium. In reducing atmosphere the maximum recommended operating temperature is 13500c.

 

 

 

 

The shaped SIC heating elements  is a linear resistance heater that converts electrical energy to heat energy(Joule's LawW = 12R). W=power in watts, l = Current in amperes, R = resistance in ohms.

 

The shaped SIC heating elements are often referred to as self-bonded, for the lattice structure or bonds that hold the elements together are formed by recrystallizing the silicon carbide at very high temperatures. The elements are manufactured of green silicon carbide which is classed as an excess electron type semi-conductor.

 

The resistance of a silicon carbide element is difficult to measure at room temperature due to minor impurities, self heating and contact resistance. Also the green silicon carbide has a negative resistance temperature characteristic from room temperature to approximately 8000C.

 

It turns positive at this point and remains so throughout its normal operating temperature range. A typical resistance temperature characteristic curve of a silicon carbide heating element is show in Fig.C

 

                           The specification for  SIC heating elements

 

Diameter of calorific section	12	14	16	20	25	30	35	40
Length of calorific section	100	100	150	150	250	300	400	400
	500	600	600	800	1500	1700	1700	2500
Length	200	300	300	700	700	700	1000	1000
	1000	1000	1300	2400	2400	3100	3100	4000
1200±50°C Resistance error range(%)	±15

 

 The relation between temperature and surface load

 

Furnace temperature(°C)	1100	1200	1300	1350	1400	1450
The surface load of calorific section(w/cm*cm)	less than 17	less than13	less than9	less than7	less than5	less than4

 

working Life for the  SIC heating elements 

 

The SIC heating elements increase gradually in resistance with use. This characteristics of increasing in resistance is called aging. Aging is a function of the following :

• Operating temperature.
• Electrical loading – usually expressed in watts per square centimeter of element radiating surface
• Atmosphere
• Type of operation (continuous or intermittent)
• Operating and maintenance techniques

Asseming for  SIC heating elements :

 

There are no restrictions on the mounting positions of  SIC heating Element, the horizontal and vertical positions are the more common. Extreme caution should be used when mounting to insure that the elements are not placed in tension. There should be adequate freedom to allow for the furnace and elements to expand and contract independently.

When mounting elements vertically they must be supported on the lower end by electrically insulated supports.

 

The SIC heating Elements should have their heating sections centered in the furnace chamber so that no portion of the heating section extends into the furnace wall. A conical or truncated cone shaped recess ? inch deep is located on each interior wall where the element passes through. This allows the hot zone to radiate properly and helps maintain a uniform temperature in the kiln.

 

Professional manufacturer of the Sic heater ,Good quality and competitive price.
Material: Silicon Carbide