Hardness Wear Cordierite Heaters Parts Ceramic Core for Bobbin Elements

Product Description

Physical properties
Gross Density	g/cm^3	2.3-2.6
Average Linear Expansion(20-1000°C)	10^-6/k^-1	6-7.6
Specific Heat Capacity	KJ/Kg	900-1200
Heat Conductivity	W/MK	1.8-3
Soft Temp.	°C	1400
Maximum Application Temp.	°C	1350
Corrosion Resistance Against Acid	%	99.5

Chemical content of each material is as below:
Power and surface load of heater tube
Surface load,that is,the electric power value taking on on unit superficial area of heating element.The higher surface use load strength of material is,the shorter life of material is,but the smaller the wastage of material is.So heating load strength of element should be chosen reasonably,making the heating element have general effect of high thermal efficiency,long life,material-save.Calculating step is as below:
1.Basic data for calculation
The highest use temperature t (C)
Heating electric power P (W)
Working voltage of element U (V)
Length of heating zone L(m)
2.The electrothermal alloy brand in use is confirmed according to basic data,combining with working condition of heating element.
3.Based on the confirmed electrothermal alloy brand in use,referring to known data,check attached table and get coefficient of correction Ct of resistance temperature.
4.Work out total resistance of material=U2 Ct/P
5.Work out resistance of per meter material Rm=R/L,combine the property of electrothermal alloy material and estimately work out the diameter of material D.Then work out total area FO of heating element.
6.The surface load of material ω is gained by ω=P/FO.If the load of surface is too large,big diameter of wire should be chosen.Currently because of limitation of heating material, the surface load of heater tube made in China should not exceed 2.0W/cm2.It can be improved properly in the condition of low temperature.