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sic heater www.china-shuangtai.com E-mail:wszbj21388@to.com

TYPE RR, SILICON CARBIDE HEATINGELEMENTS

RR型硅碳棒电热元件

GENERAL DESCRIPTION 概述

The RR Element is a resistance type silicon carbide heating element. Elements are rod shaped or tubular depending on the diameter. They have a central heating section referred to as a hot zone and two terminal sections called cold ends. There are two types of RR Elements. (1)The cold ends are impregnated with silicon metal -- referred to as one piece, and (2) low resistance cold ends which are furnace welded to the hot zone -- referred to as a three piece or LRE (Low Resistance End) type. This lower electrical resistance cold end causes them to operate at a lower temperature. The extremities of the elements are metallized with aluminum to provide a low resistance contact surface to which the electrical connections are made using braided aluminum straps.

RR型硅碳棒是带有一定阻值的电热元件。该产品根据直径不同有棒状或管状之分。这种硅碳棒有一个中央暖气系统,即中间发热部和两头的冷端部。我们有两种RR型硅碳棒:(1)两头的冷端部充满了硅金属——就如一整段;(2)两头的冷端部阻值比较低和发热部焊接在一起——相当于三段或者说是终端低阻值型。这种低阻值的硅碳棒可以使其控制在一个低温环境中。这种发热元件的终端两头是通过金属铝处理来使其解除表面保持较低阻值,电路连通是用铝带来完成的。

RR Elements are described by giving the overall length, the heating section length, and the diameter. As an example, RR 43 x 24 x 1 is an element 43" overall with a 24" hot zone, and 1" in diameter.

RR型硅碳棒的总长、发热部的长度和直径会给出。例如,RR43 x 24 x 1是指其总长为43英寸,发热部长为24英寸,直径为1英寸。

SUPERIOR PERFORMANCE 优越性能

Elements will give you superior performance due to their high density – approximately

2.4 gms/cc. This gives the element very slow aging characteristics and additional strength.

由于该产品具有2.5 gms/cc的高密度,将会带许多来特殊性能。硅碳棒有着老化极度缓慢的特性,还有会比通常的要格外的结结实。

INTERCHANGEABILITY 可替换性

Elements are interchangeable with all silicon carbide heating elements manufactured in the United States as well as higher resistance heating elements manufactured for the Asian and European markets. It is important to provide the nominal electrical resistance when ordering eements. Please contact us, before attempting to substitute

我们制造的硅碳棒均具备可替换性,也为美洲和欧洲市场生产很多高阻值发热元件。当定购这种发热元件时,提供额定电阻也是非常重要的。当您打算替换时请先联系我们。

SIZES AVAILABLE 有效尺寸

Elements can be manufactured in any length up to 130 inches (3300mm). The maximum hot zone length is 98 inches (2500mm).

这种硅碳棒可以制造最长达到130英寸(3300mm)的任意长度。发热部的最大长度是98英寸(2500mm).

OPERATING TEMPERATURES 操作温度

In an air or inert atmosphere of argon or helium the one piece Elements can be operated at furnace control temperatures up to 3100F (1700C), the three piece element up to 2600F (1425C). In reducing atmospheres the maximum operating temperature is 2500F (1370C), see Figure 1. There is a protective coating of silicon dioxide on the silicon carbide. Hydrogen reduces this coating and causes the element to deteriorate. Very dry or very wet hydrogen is detrimental to long service life.

在空气或者氩、氦等惰性气体环境中,整段的硅碳棒在熔炉内的操作温度最高可达3100F (1700C),另一种三段的RR型硅碳棒的最高操作温度可达2600F (1425C). 在还原空气时最高操作温度可达2500F (1370C),详见图1。在硅碳棒表面有一层二氧化硅保护涂层。氢气容易缩小这个保护层以致其恶化。极干或者是极湿的氢气对延长产品的使用寿命都是有害的。

Nitrogen atmosphere applications are limited to 2500F (1370C) and 20 to 30 watts per square inch (3.1 to 4.6 watts per square centimeter) maximum surface watt loading. Too high of a surface temperature will result in a silicon nitride reaction. A thermally insulative layer forms around the Element resulting in very high surface temperatures which damage the elements.

氮保护气氛的应用温度限制在2500F (1370C)下,最大表面负荷能量为20到30瓦每平方英寸(或者是3.1到4.6瓦每平方厘米)。表面温度过高容易导致硅、氮发生反应。表面温度过高容易形成一个隔热层,这样会破坏其性能。

ELECTRICAL CHARACTERISTICS 电子特征

The silicon carbide element is a linear type resistance heater that converts electrical energy to heat energy -- Joule's Law W = I² x R, (W = power in watts, I = current in amperes, R = resistance in ohms).

这种硅碳棒加热器具有一种线性电阻,将电能转化为热能——Joule's定律W = I² x R, (W 是瓦特能量, I = 安培电流, R = 电阻欧姆).

The element hot zone is a self bonded silicon carbide. The lattice structure or bonds that hold the silicon carbide grain together are formed by recrystallizing the silicon carbide at very high temperatures. Elements are manufactured of green silicon carbide that is classed as an excess electron type semiconductor.

这种硅碳棒的发热部是自发结合的碳化硅。在温度非常高时,通过再结晶形成这种晶体结构或者说是碳化硅颗粒聚合物。这种硅碳棒由一种新型的碳化硅制成,被归类为超级半导体。

The electrical resistance of an 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 1200F (650ºC). It turns positive at this point and remains so throughout its normal operating temperature range. A typical resistance temperature characteristic curve of an element is shown in Figure 2.

这种硅碳棒的电阻在室温时很难测量其阻值,因为含有少量杂质,自行加热,还有顺变电阻。这种新型的碳化硅除在室温至1200F (650ºC)范围内其存在负阻值。在这个温度下时,阻值变为正值,并在整个正常操作温度范围内保持正值。参见图2中典型的温度电阻曲线图。

Nominal element resistance is measured at the calibrating temperature of 1960ºF (1071C). Nominal resistance values of elements in ohms per unit of length are shown in Table A, page 5.

在校准温度1960ºF (1071C)下,可测量该产品的额定电阻。每单元长度的额定阻值详见第5页的表格A。

ELECTRICAL LOADING 电子负荷

Elements are not sized to a specific wattage output like metallic heating elements. The amount of energy that an element is capable of converting from electrical to heat energy depends on the ambient furnace temperature and atmosphere in which the element is operating.

和金属加热元件一样,这种硅碳棒不是用特定的输出功率来衡量的。主要依赖于周围的环境和熔炉温度使大部分能量主要由点能转化为热能。

When calculating the wattage capabilities of an element, the unit of watts output per unit of radiating surface area is used. Figure 1 shows the recommended watt loading for a square inch or square centimeter of radiating surface as a function of furnace temperature.

当计算其能量时,要用到每单元辐射面积的输出功率。图1中指出了每平方英寸或者是每平方厘米辐射面积所能负荷的理想能量和熔炉温度的函数关系。

To determine the recommended wattage capabilities of the elements start with Figure 1, knowing the furnace temperature and atmosphere in which the elements will be operated. Follow the temperature line until you intersect the heavy black line (choosing the appropriate line according to the atmosphere in which the element will be operating).

要测算其理想的负荷能量看图1后,了解到将在何种熔炉温度和大气环境下进行温控。根据图中的黑色粗线表示的温控线(根据大气温度选择一个适当的温控线)。

Read the loading in watts per square unit of radiating surface that can be applied to the

element. To find the total amount of power one element could supply under these conditions, multiply this value by the radiating surface of the element. The radiating surface area is calculated by multiplying the diameter times the hot zone length times pi (3.14).

知道了能应用到硅碳棒的每平方单元辐射面积所能负荷的能量。在这些条件下,得知一根这种硅碳棒所能提供的总的功率,需乘以其辐射面积。计算辐射面积是用直径乘发热部的长度乘3.14。

Example: At 2750F the element could be loaded to 35 watts per square inch. Therefore, an element with 10 square inches of radiating surface could supply 350 watts, whereas an element with 200 square inches of radiating surface could supply 7000 watts.

(At 1500C the element could be loaded to 6 watts per square centimeter. Therefore, an element with 100 square centimeters of radiating surface could supply 600 watts, whereas an element with 2000 square centimeters of radiating surface could supply 12,000 watts).

例如:温度为2750 F时,负荷能量为35瓦每平方英寸。因此,10平方英寸的辐射面积能提供350瓦的能量,同样的,200平方英寸的辐射面积能提供7000瓦的能量。

(温度为1500C时,负荷能量为6瓦每平方厘米。因此,100平方厘米的辐射面积能提供600瓦的能量,同样的,2000平方厘米的辐射面积能提供12000瓦的能量)。

Example of radiating area: The RR 43 x 24 x 1 has a hot zone length of 24 inches on a diameter of 1 inch. The radiating surface area is 24 x 1 x 3.14, or 75.4 square inches. (The RR 1092 x 610 x 25 has a hot zone length of 610mm and a diameter of 25mm. The radiating surface area is 610 x 25 x 3.14 or 47,885 square mm, converted to centimeters is 478 square centimeters).

例如辐射面积的计算:RR 43 x 24 x 1,发热部长度为24英寸,直径为1英寸。辐射面积为24 x 1 x 3.14即75.4平方英寸。

(RR 1092 x 610 x 25,发热部长度为610毫米,直径为25毫米。辐射面积为610 x 25 x 3.14即47885平方毫米,转换成厘米即是478平方厘米)。

POWER SUPPLY 能量供应

In the previous paragraph we explained how to calculate the recommended wattage output of the element. Now we shall explain how to compute the electrical requirements to provide the recommended power.

在前面的篇幅中讲了如何计算理想输出功率。现在我们将说明如何计算电子设备的能量。

Knowing the wattage output and the resistance of the element you have two parts of an equation with three unknowns. This equation is E = √(W x R), (E = nominal full load voltage, W = rating of the element in watts, R = resistance of the element in ohms). The resistance of the element can be calculated using the values found in Table A.

知道了输出功率和电阻阻值,该公式有三个未知量,其关系式是E = √(W x R), (E = 额定电压, W =辐射能量瓦数, R = 电阻欧姆).电阻阻值可以用表格A中的数据计算出来。

When solving for E, you would obtain the voltage required on a nominal resistance element to provide the wattage output desired.

当计算E值时,所得电压值必须是根据标称电阻计算出来的。还需提供其输出功率的瓦数。

Example: An element RR 43 x 24 x 1 has a resistance of 1.21 ohms and 75 square inches of radiating surface. Loading to 40 watts per square inch, this element could provide 3000 watts. To find the nominal voltage solve for E.

E = √(W x R)

E = √(3000 x 1.21)

E = 60 volts

例如:已知RR 43 x 24 x 1,电阻为1.21欧姆,其辐射面积为75平方英寸。每平方英寸的面积负荷40瓦的能量,这种硅碳棒能提供3000瓦的能量。计算出E的额定电压值。

E = √(W x R)

E = √(3000 x 1.21)

E = 60 伏

Elements may be connected in parallel, series, or combination thereof. Parallel connections are preferred.

这些硅碳棒可以是并联的,串连的,或者是将串并联混联的。通常采用并联。

In a parallel arrangement the voltage across all the elements is the same. In the formula W = E² R, (W = watts, E = voltage, R = resistance) it can be seen that the greater the resistance, the lower the wattage output. The elements in the parallel circuit with the lowest resistance will supply more heat energy and therefore operate at a higher temperature. This higher element temperature will cause it to gradually increase in resistance until all the elements have the same resistance. At this time the elements should all have approximately the same resistance values and surface temperatures and therefore remain in balance.

并联电路的电压处处相等。由公式W = E²R, (W 功率, E =电压, R =电阻)可以看出,电阻越大,输出功率越小。要使并联电路中的电阻阻值达到最小值应供应更多的热能,这样可以使操作温度更高。这种高温环境可以使电阻阻值越来越大,直至所有的电阻都近似等于一个相同的阻值。此时所有的电阻都有一个相同的阻力系数和表面温度,因此可以最终保持平衡。

To compute the network resistance of a group of elements the following formula may be used: Rn = R x S P (Rn = network resistance, R = resistance of element, S = number of elements connected in a series, P = number of parallel circuits).

要计算总阻值可以用下面这个公式:Rn = R x S P (Rn 总电阻, R = 单个电阻, S =每一组串联的数量, P = 并联电路的数量).

Example: Eight elements RR 43 x 24 x 1 (R = 1.21 ohms) connected 2 in series

(S = 2) and 4 parallel groups (P = 4).

Rn = R x S P

Rn = 1.21 x 24

Rn = 0.6 ohms

例如:8个RR 43 x 24 x 1 (R = 1.21 欧姆),每2个串联在一起(S = 2),共有4组并联(P = 4).

Rn = R x S P

Rn = 1.21 x 24

Rn = 0.6 欧姆

To compute the nominal voltage required to power a set of elements, we shall use a combination of the formulas used in the two previous examples. En = √(Wt x Rn), (En = nominal network voltage, Rn = network resistance, Wt = total wattage output).

要计算额定电压需要知道一组功率值,我们可以将前面提到的两个例子结合起来。En = √(Wt x Rn), (En =额定电压, Rn = 总电阻, Wt =总的输出功率).

Example: Eight elements RR 43 x 24 x 1 (R= 1.21 ohms) connected 2 in series, 4 parallel groups. Each element provides 3000 watts. Wt = 8 x 3000 = 24,000 watts. Rn = 0.60 ohms.

En = √(Wt x Rn)

En = √(24,000 x 0.6)

En = 120 volts

例如:8个RR 43 x 24 x 1 (R= 1.21欧姆),每2各串联在一起,组成4个并联组。每个硅碳棒可提供3000瓦。Wt= 8 x 3000 = 24,000瓦。Rn = 0.60欧姆。

En = √(Wt x Rn)

En = √(24,000 x 0.6)

En = 120 伏特

The resistance of elements increases gradually during their useful life. Therefore, some means of keeping the power input to the kiln or furnace at a level sufficiently high to maintain the desired temperature is required.

该产品的电阻值在其有效使用期限内,阻值是逐渐变大。因此,某种程度上来讲,保持管内输入功率能量或者是熔炉的温度足够高是必须的。

Historically, expensive voltage varying equipment such as multiple tap transformers or saturable reactors were recommended for all but the very low temperature applications.

在这以前,均建议通过变压器或者是saturable反应堆大幅度改变设备电压,但是这只能应用于较低的温度条件。

Elements can be used directly on the line (fixed voltages) at temperatures up to 2400F

(1315C). To compensate for the reduced output as the elements gradually age or increase in resistance, the furnace or kiln is initially overpowered by 25% to 50%. This type of arrangement eliminates the expensive voltage varying equipment and has proven very satisfactory in many applications. It is not recommended when fine process temperature control is required.

该产品可以即刻被使用(固定电压)直到温度达到2400F(1315C).由于产品逐渐老化或者是电阻阻值逐渐增大导致功率减小,为了补偿这部分损失的功率,刚开始的熔炉或者使管的功率会增大25%到50%。这样是为了消除大幅度改变设备电压所带来的误差,而且这种方法在实际应用中已经得到很好的证明。在精确温控条件下不推荐使用这种方法。

Assume a furnace will require approximately 24,000 watts after all heat losses and load factors have been considered. Increasing this 24,000 by 25% to 50% gives a wattage requirement of between 30,000 and 36,000 watts.

假定在考虑了热量散失和负载等因素之后一个熔炉大约需要24000瓦的能量。将这个功率值增加25%到50%之后所需的功率在30000瓦到36000瓦之间。

By taking another look at the previous examples it can be seen that 10 elements RR 43 x 24 x 1 connected two in series, five parallel groups on 120 volts would supply the 30,000 watts. If 12 elements of the same size were used, the output would be 36,000 watts. Twelve elements connected four in series per phase on 240 volts would make a balanced three phase 240 volt network.

我们再看一下前面提到的例子,可以得知10根RR43 x 24 x 1型硅碳棒每两个串联在一起,组成5个并联的组,连接在120伏的电压下,这样可以提供30000瓦的能量。如果用12根同样型号的硅碳棒,输出功率即为36000瓦。12根硅碳棒每4个串联在一起,每一段接在240伏特的电压下,那么同样的三组并联在一起就可以保持平衡。

The temperature of the kiln or furnace is controlled by an off-on controller. When the elements are new they will only be powered for 24/30 or 24/36 of an hour. As the elements increase in resistance they will be on for a greater percentage of the time. When they have increased in resistance to a point at which they supply 24,000 watts, they will be on 100% of the time. A SCR (silicon controlled rectifier) or thyrister can also be used.

炉内温度由开关控制。刚开始使用全新的硅碳棒时,每小时供应24/30或24/36的能量。随着使用期限内其阻值逐渐变大,这个百分比会有所提高。当电阻阻值增大到一个临界值及输出功率为24000瓦时,这个百分比刚好达到100%. 也可以用可控硅整流器或者是半导体闸流管。

For applications where close temperature control is desired and/or for temperatures above 2400ºF (1315ºC) a device for increasing the voltage to the elements is required. There are several methods of providing this variable voltage source:

在实际应用过程中最好接近控制温度或者高于2400ºF (1315ºC)时装置需要增加电压。下面有几个办法可以改变电压:

(1) The multiple tap transformer is the most common, because it is usually the least expensive. The secondary of the transformer is provided with taps which usually vary in number from 10 to 36. By carefully selecting the voltage taps, the correct voltage output to match the resistance of the elements over their complete useful life can be made.

(1)多孔变压器是最常用的方法,因为成本最低。其次变压器有一些插孔,可以在数字10到36之间变化。仔细选择电压插孔,选择和电阻相匹配的输出电压值,这样可以延长其有效使用寿命。

(2) Saturable reactors and induction regulators are used to provide a stepless voltage control. They are also sometimes used with multiple tap transformers.

(2)可用Saturable反应堆和电感式电压调节器来供应无极控制电压。有时候也和多孔变压器一起使用。

(3) Capacitor controls are used infrequently. They, of course, will tend to improve a power factor, which makes their use desirable in some areas.

(3)很少使用电容控制器。当然,现在趋向改进原子能因素,这样可以在某些领域值得应用。

(4) Silicon controlled rectifiers, (SCR) have become quite popular with the advances in solid state devices.

(4)在固态元件领域可控硅整流器应用的非常广泛。

To compensate for the reduced output as the elements increase in resistance, a voltage range is required that will compensate for a 100% increase in the element resistance. The following formula may be used to calculate Emax : Emax = √(Wt x Rn) x 1.5, (Emax = recommended maximum voltage required to compensate for increase in resistance due to aging and resistance tolerance, Wt = rating of transformer in watts, Rn = network resistance of the elements, 1.5 = minimum margin to accommodate the doubling of the element resistance and the +20% resistance tolerance). A higher value will offer slightly longer usable service life.

由于电阻逐渐增大导致输出功率逐渐减小,为了补偿减少的这部分能量,将其补偿到100%必须在电压范围内完成。下面这个公式可以用来计算电压的最大值:Emax = √(Wt x Rn) x 1.5, (Emax =考虑由于老化等因素导致电阻增大而补偿后的最大电压值, Wt =变压器额定功率, Rn =电路总电阻, 1.5 =电阻增到20%后所能负荷的最小系数)。这个可以稍稍延长产品的使用寿命。

Example: The transformer is rated at 24 KVA and has a computed nominal full load voltage of 120 volts. (Rn = 0.6, Wt = 24,000).

Emax = √(Wt x Rn) x 1.5

Emax = √(24,000 x 0.6) x 1.5

Emax = 180 volts

例如:已知变压器的额定功率为24千伏安和额定满负电压为120伏特(Rn = 0.6, Wt = 24,000)。

Emax = √(Wt x Rn) x 1.5

Emax = √(24,000 x 0.6) x 1.5

Emax = 180 伏

The nominal full load voltage and maximum voltage have been computed. When specifying the transformer the nominal full load voltage is usually reduced by 5% to 10% to allow for the minus 20% resistance tolerance of the elements. Also, lower voltage taps are usually provided for idling and slow heatups.

以上已计算出额定满负电压和最大电压。考虑到要减去20%的电阻阻值,通常将额定满负电压值减去5%到10%。通常在机器空转或者缓慢加热时用到低电压插孔。

To calculate the minimum voltage, take 70% of the nominal voltage. For periodic applications, take 30% of the nominal full load voltage.

计算最小电压值时,通常取其额定电压的70%。由于周期使用,去除掉额定满负电压的30%。

Auto transformers may be used if primary voltage is 230 volts or less. They should not be used in a three phase arrangement. Accepted practice limits the secondary voltage on all transformers to 300 volts. Above this refractory voltage leakage becomes a problem. When computing the size of the voltage steps between taps, a value of 5% of the nominal full load voltage is often used. When SCR or thyrister controls are used on the primary, fewer taps are required. For example, if 6 taps are used, the idling tap can be 0.7 x nominal voltage, then each consecutive tap would be 14% higher. For 8 taps, the idling tap would again be 0.7 x nominal voltage, each consecutive tap at 9.1% higher than the preceding.

自动变压器用于电压小于或者等于230伏的情况。不可以用在三相电路中。实际应用时一半用于300伏的变压器中。以上这个电压遗漏问题很难控制。当处理插孔间的电压阶越数值时,通常是用到额定满负电压的5%。假若一开始就用可控硅整流器或者是半导体闸流管时,需要的插孔会相对少些。例如,如果需要6个插孔,机器空转时用到0.7 x的额定电压,每个连续的插孔会高些即14%,每个连续的插孔会比先前的高出9.1%。

推荐间距

X = 最小值为2 x 直径, 绝对极小值为1.5 x直径,需要减去一个表面负荷瓦数

Z = 静荷载最小值为S ÷ 1.41

Z = 活动荷载最小值为S ÷ 1.73

S = 最小值为2 x 直径

X – 中心线到任意其它反射面的距离,比如难熔壁或者产物

Z - 中心线到任意静荷载或活动荷载的距离

S – 相邻两中心线的距离

EASE OF REPLACEMENT 可替换性

Elements can be replaced while the furnace is at operating temperature. The power to the elements being changed should be shut off, the spring clips and aluminum braid released, and the old element removed. The new Element should be inserted smoothly through the hot furnace with sufficient speed to insure that the aluminum is not melted off the terminal end but not so fast as to cause thermal shock.

在温控范围内该种硅碳棒可以被替换。当改变功率时需关闭电源,让弹簧夹具和喷铝部可以释放出来,将原先的的拿走。新的硅碳棒应该轻轻的迅速放入熔炉,以确保铝不在终端被氧化,否则可能会导致温度急增。

SERVICE LIFE 使用寿命

Elements increase gradually in resistance with use. This characteristic of increasing in resistance is called aging. Aging is a function of the following:

(1) Operating temperature

(2) Electrical loading (usually expressed in watts per square inch or watts per square centimeter of element radiating surface)

(3) Atmosphere

(4) Type of operation (continuous or intermittent)

(5) Operating and maintenance techniques

在使用过程中电阻会逐渐增大。这种特性叫做老化。老化主要由以下几个因素造成:

(1) 控制温度

(2) 电子负荷(通常用每平方英寸或者每平方厘米的辐射面积所能负荷的瓦数来表示)

(3) 大气环境

(4) 控制类型(连续的或者是间歇的)

(5) 维护技术

MOUNTING 安装系统

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

该产品在安装上没有什么特别的限制,立式的和卧式的都很普及。安装终端时必须确保不能紧绷。必须保证在熔炉内可以独立地伸缩自如。

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

当垂直安装时,应该支撑在较低的绝缘体上。

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 1/2 inch (13mm) deep is sometimes 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.

该产品在装入熔炉内时应该确保其发热部不能超出炉壁的范围。在位于每一个穿过的管壁内有一个类似锥形体或者截面锥形体的凹槽,大约1/2英寸(13mm)长。

FURNACE HEATING CHAMBER 高温炉腔

The furnace heated chamber dimension, which the element spans, can be the same as the hot zone length of the element as shown by the elements under the load in Figure 3. Alternately the furnace heating chamber dimension, which the element spans, can be one inch (25mm) less than the effective heating length of the element. In this case there must be a 45conical recess in the furnace wall as shown in Figure 3 for the elements above the load. Recommended terminal hole diameters for various refractory walls and element sizes are shown in Table B.

炉壁的间距和发热部的长度尺寸是一样的,具体如图3所示。当炉腔的两壁间的长度比硅碳棒的有效发热长度短1英寸(25mm),这种情况下应该在炉壁上设一个45的锥形角,详见图3。硅碳棒终端孔径具体数值在表格B中列出。

Elements should not be placed closer than two element diameters to each other or one and one half element diameters to a wall or other reflecting body. If the element is not able to dissipate heat energy equally in all directions, it may cause local overheating and possible failure.

孔与孔之间的距离不小于元件直径的两倍,元件与炉壁、反应物件的距离不小于直径的1.5倍。如果硅碳棒不能再各个方向上均匀散热,可能会导致部分区域受热过度乃至失败。

The formula for computing the recommended element spacing to obtain an even temperature gradient on the product being heated is shown in Figure 3.

通过间距计算公式得知加热产物温度梯度,具体详见图3。

SPECIFICATIONS AND MATCHING 匹配规格

Elements have a manufactured tolerance of plus or minus 20% on the nominal resistance. All elements are calibrated at least twice prior to shipping to ensure their being within specifications. The calibrated amperage of each element is marked on the carton and right hand end of each element. When installing, arrange elements with amperage values as close to each other as available. Longer service life will be obtained when series connected elements are matched in resistance. Elements are shipped as closely matched as possible.

硅碳棒的额定阻值有一个正负20%的公差范围。所有产品在发货前至少校准两次以确保其规格的准确性。每个硅碳棒的校验电流安培数在集装箱的右下角都有标记。串联的阻值相匹配可以延长产品的使用寿命。我们会尽量按照匹配的规格发货。

AVAILABILITY 实用性

Elements can be shipped from stock, or two to three weeks after receipt of an order.

这种硅碳棒可以从库存处发货,或者在收到订单2到3周后发货。

CUSTOM CONFIGURATIONS 常用结构

Special sizes and shapes are available. Cold ends can be different lengths. This, for example, would be applicable for furnaces with arched roofs that require longer cold ends through the roof and shorter through the floor.

一般用的都是专门尺寸和形状的硅碳棒。冷端部可以制成不同的长度。比如,在熔炉应用中可以制成弓形,穿过炉顶的冷端部比较长,穿过炉底的冷端部比较短。

Another modification is a two-temperature hot zone. This, for example, would be helpful to get additional heat energy into the lower, more densely loaded tunnel kiln. While this special modified hot zone will not create a specific temperature differential, it does offer a convenient way to get more heat energy into a specific area of a furnace.

另一种改进模式是有两个温度发热部。例如,这种形式有助于减少多余的热量,管内可以负荷更多的能量。这种特殊的改良后的发热部不会引起特别的温度变化,反而更方便的使熔炉内一些特别区域得到更多的热量。

The right angle (RA) shown here, has all the electrical characteristics of the RR. The cold ends are attached perpendicular to the hot zone. The RA is normally installed with the cold end through the roof of the furnace.

在图中可以看出直角部分,具备RR型硅碳棒的所有电子特性。冷端部和发热部垂直。通常安装时冷端部穿过炉顶。

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更新时间:2025/2/23 17:44:06