产品描述:

上海工陶陶瓷有限公司（Gongtao）是中国最领先和先进的集设计、制造和营销的高科技陶瓷材料公司之一。品牌“上陶-SHANGTAO”成立超过20年。我们专注于氧化铝产品，氧化锆产品，氧化镁产品，有机硅氮化物产品和铝氮化物产品。我们已经开发出先进的技能和技术。我们的产品被广泛应用于电力，信息，电力，汽车和其他领域。

工业陶瓷：氧化铝陶瓷，氧化锆陶瓷，钛氧化物陶瓷，碳化硅陶瓷，氧化硅陶瓷，特种陶瓷，高频陶瓷，莫来石陶瓷，日用陶瓷，耐火陶瓷，电子陶瓷，纺织陶瓷，高纯度的氧化铝坩埚，电气陶瓷等

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产品图片：

辐射管 
产品简介

   
产品采用可控气氛的各种热处理炉中，为了避免燃料燃烧产物与工件的接触，或是为了避免炉气对电热元件的侵蚀，将燃料燃烧或电能转变的过程放在耐热钢管中进行，让热量通过管壁辐射给工件，这种装置称为辐射管。

   
电热辐射管是把电热元件封闭在保护套内，通电加热后，由套管间接地把热量辐射给炉衬和被加热工件。辐射管的加热适用于通保护气氛的和有腐蚀性气氛的炉子，如连续炉、滚筒炉、井式炉等等。

   
将电阻丝以轴向进行波折，即将单根电阻丝弯成U形，再互相串联或并联在一起的电热辐射管叫做波折式电阻丝辐射管。这种装配方式的辐射管，由于电阻丝的屏蔽作用降低，在管内较高的表面负荷下，也能确保长时间的使用寿命。

辐射管有下面几个优点：

（1）
可以保证炉内气氛的可控性

（2）
温度控制、安装和维修较方便，易于密封；

（3）
由于炉内无马弗罐，扩大了炉膛容积，提高了生产能力

（4）
加热能力强，效率高

（5）
节约了耐热钢材

辐射管
>>
产品使用材料

   
辐射管使用的电热合金材料应具有较高的电阻率，电热转化率高。由于辐射管放置在套管内，传热过程与一般敞露型电热元件不同，其热屏蔽大，升温过程中必须对元件温度进行控制，防止元件超温。辐射管封闭加热时，电热元件表面温度比炉膛温度高约100℃-150℃。所以在选材时要分析炉温、炉内气温氛围，选择正确的加热材料。

   
本公司生产的辐射管常使用Cr20Ni80（镍铬系）Cr25A15、Cr21A16Nb、Cr27A17Mo2（铁铬铝系）等材料，各材料化学成份/%如下表：

    
Cr20Ni80使用在500℃-800℃之间，因其稳定的、单一的、均匀的固熔体组织，所以具有良好的常温和高温力学性质，均匀的电气物理性质以及良好的加工工艺性质。使用温度低，使用寿命长，不易损坏等方面区别于铁铬铝系电热合金材料。

    
Cr25A15、Cr21A16Nb、Cr27A17Mo2使用在800℃-1200℃之间，三种材料使用温度依次升高。塑性低，脆性高是铁铬铝系电热合金材料最大的缺点，特别是在400℃-800℃之间，长时间使用会使材料内析出“CrFe”型金属化合物，引起合金塑性急剧下降，出现严重脆化现象，所以铁铬铝系电热合金材料要避开在此温度区域内进行成形加工和使用。

辐射管
功率及表面负荷
   
表面负荷是指电热元件的单位表面积上所担负的电功率值。材料的表面使用负荷强度越高，材料的使用寿命越短，但材料的消耗量也越小。所以，要合理的选择元件的热负荷强度，使电热元件具有热效率高、寿命长、节省材料的综合效果。计算步骤如下：

（1）计算需要的基本数据

    
最高使用温度t（℃）

    
加热电功率P（W）

    
元件工作电压U（V）

    
发热区长度L（m）

（2）根据基本数据，结合电热元件的工作条件，确定使用的电热合金牌

（3）根据确定使用的电热合金牌照，参照已知数据，查附表得出电阻温度修正系数Ct。

（4）计算出材料总电阻=U2
Ct/P

（5）计算出每米材料电阻Rm=R/L，结合电热合金材料性质估算出材料直径D，再计算出电热元件总面积FO。

（6）由ω=P/FO得出材料的表面负荷ω，如果表面符合过大，则选择大的丝径。现国产辐射管因加热材料限制，表面符合应不超过2.0W/cm2,低温情况下可适当提高。

Introduction:

The
product is ued in controllable aural various heat
treatment furnace,to avoid
the contact of elding burning outcome or to avoid the
corrosion of furnace
gas to heating element.The process(the conversion of
elding burning or
electric
energy)
is put into refractory steel tube and let amount
of
heat radiate by wall of tube.This device is called as heater tube.

Electrothermal
heater
tube will close the heating element in the jacket,after electrify and
heat
up,the heat is indirectly radiated to furnace liner and workpiece to
be
heated by bushing.The heat up of heater tube is used in furnace with
going
protecting aural and corrodent aural,such as continuous furnace,roller
furnace,
pit furnace.

Twist
and
turn resistance wire in axial direction,that is,the single resistance
wire is
bended to U shape,then in series or parallel connection mutually.This
kind of
electrothermal heater tube is called bending resistance wire heater
tube.This
tube,because fall of screening of resistance wire,in intratubal
upper surface
load,can insure prolong life span.

The
advantages of tube:

1.    The
controllability of aural inside furnace can be guaranteed.

2.    The
control of temperature,assemble and maintainace are very convenient and can be
easy to
sealed.

3.    The
cubage of hearth is enlarged and throughput is improved because of no muffle
pot

4.    trong
heating ability and high efficiency

5.    The
refractory steel material is save.

The
material of tube:

The
electrothermal alloy material that heating tube apply should be of
higher
resistance rate.The percent
conversion
of galvanothermy is high.Because the heating tube is put in the
bushing,the
process of heat transmission is different from that of open type
heating
element.Its heat shield is big.The temperature of element must be
controlled
at the course of temperature rise,to avoid temperature excursion
of
element.

When
the heater tube is closed and heated,the
surface temperature of
heating
element is higher roughly than temperature
of hearth by 100 C~150
C.So
temperature of furnace and atmosphere of temperature of furnace are
needed to
analysed.Choose correct heating material.   

The
heater tube produced by gongtao company often
apply Cr20Ni80,Cr25A15,Cr21A16Nb,Cr27A17Mo2 ect.

Chemical
content of each material is as
below:

Cr20Ni80
is used between 500 C and 800
C,because of steady,single even solid
fusant
form,It
has good normal temperature and high temperature mechanics
property,even
electric physical property and good machining technics
property.Low use
temperature,long life,no easy damage ect are different from
Cr27A17Mo2
electrothermal alloy
material.

Cr25A15、Cr21A16Nb、Cr27A17Mo2 is used between
800
C~1200C.The use temperature of these three material is hoisting in
turn.
Plasticity is low.High brittleness is the biggest shortcoming of Cr27A17Mo2.Especially
when 400℃-800℃,long
use will make material precipitate
“CrFe”
type metal compound,which arose sharp fall of
alloy plasticity.
Severe embrittlement
phenomenon will appear.So Cr27A17Mo2 electrothermal
alloy material
carry through formation,process and use,kept away from in this
temperature
range.

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.