本帖最后由 龟山淬火 于 2017-8-10 15:25 编辑
Induction heating is a process which is used to bond, harden or soften metals or other conductive materials. For modern manufacturing processes, induction heating offers an attractive combination of speed, consistency, control and energy efficiency. The basic principles of induction heating have been understood and applied to manufacturing since the 1920s. During World War II, the technology developed rapidly to meet urgent wartime requirements for a fast, reliable process to harden metal engine parts. More recently, the focus on lean manufacturing techniques and emphasis on improved quality control have led to a rediscovery of induction technology, along with the development of precisely controlled, all solid state induction power supplies. How induction heating works?When an alternating electrical current is applied to the primary of a transformer, an alternating magnetic field is created. According to Faraday’s Law, if the secondary of the transformer is located within the magnetic field, an electric current will be induced. In a basic induction heating setup, a power supply sends an AC current through an inductor (often a copper coil), and the part to be heated (the workpiece) is placed inside the inductor. The inductor serves as the transformer primary and the part to be heated becomes a short circuit secondary. When a metal part is placed within the inductor and enters the magnetic field, circulating eddy currents are induced within the part. 感应加热是用来粘结、硬化或软化金属或其它导电材料的过程。在现代制造过程中，感应加热提供了速度、一致性、控制和能源效率的诱人结合。自20世纪20年代以来，感应加热的基本原理已被理解并应用于制造业。二战期间，该技术迅速发展，以满足迫切的战时要求，以快速、可靠地硬化金属发动机部件。最近，对精益制造技术和改进质量控制重点的关注导致了重新发现感应技术，随着精确控制，全固态感应电源。感应加热是如何工作的？当交流电流应用于变压器的初级时，就会产生交变磁场。根据法拉第定律，如果变压器的次级位于磁场中，就会产生电流。在基本感应加热装置中，电源通过感应器（通常是铜线圈）发送交流电流，待加热的部分（工件）放在感应器内部。电感器作为变压器初级部分，待加热部分成为短路次级。当金属部件放置在感应器内并进入磁场时，零件内就会产生循环涡流。Induction heating fundamentals
As shown in the diagram, these eddy currents flow against the electrical resistivity of the metal, generating precise and localized heat without any direct contact between the part and the inductor. This heating occurs with both magnetic and non-magnetic parts, and is often referred to as the “Joule effect“, referring to Joule’s first law – a scientific formula expressing the relationship between heat produced and electrical current flowing through a conductor. Induction heating benefitsWhy choose induction heating over convection, radiant, open flame or another heating method? Here’s a short summary of the major advantages that induction heating offers for manufacturing: Maximized ProductivityProduction rates can be maximized because induction works so quickly; heat is developed directly and instantly (Example >1000ºC in <1 second) inside the part. Start-up is virtually instantaneous; no warm up or cool down cycle is required. The induction heating process can be completed on the manufacturing floor, next to the cold or hot forming machine, instead of sending batches of parts to a remote furnace area or subcontractor. Energy EfficiencyThis uniquely energy-efficient process converts up to 90% of the expended energy into useful heat; batch furnaces are generally only 45% energy-efficient. And since induction requires no warm-up or cool-down cycle, stand-by heat losses are reduced to a bare minimum. Control and automation processInduction heating eliminates the inconsistencies and quality issues associated with open flame, torch heating and other methods. Once the system is properly calibrated and set up, there is no guess work or variation; the heating pattern is repeatable and consistent. With GH power supplies, precise temperature control provides uniform results; power can be instantly turned on or shut off. With closed loop temperature control, advanced induction heating systems have the capability to measure the temperature of each individual part. Specific ramp up, hold and ramp down rates can be established & data can be recorded for each part that is run. Product QualityWith induction, the part to be heated never comes into direct contact with a flame or other heating element; the heat is induced within the part itself by alternating electrical current. As a result, product warpage, distortion and reject rates are minimized. For maximum product quality, the part can be isolated in an enclosed chamber with a vacuum, inert or reducing atmosphere to eliminate the effects of oxidation. Green energyInduction heating systems do not burn traditional fossil fuels; induction is a clean, non-polluting process which will help protect the environment. An induction system improves working conditions for your employees by eliminating smoke, waste heat, noxious emissions and loud noise. Heating is safe and efficient with no open flame to endanger the operator or obscure the process. Non-conductive materials are not affected and can be located in close proximity to the heating zone without damage. Using GH induction heating solutions means to improve the installation operation and maintenance, to avoid production stoppages, to reduce the energy consumption and to increase the parts quality control.如图所示，这些涡流与金属的电阻率相流动，产生精确且局部的热量，而不产生部分和电感器之间的直接接触。这种加热是由磁性和非磁性两部分组成的，通常被称为“焦耳效应”，指的是Joule的第一定律——一个表示热产生与电流通过导体之间关系的科学公式。感应加热的好处为什么选择感应加热对流，辐射，明火或其他加热方式？这里是为制造提供感应加热的主要优点是一个简短的总结：最大的生产力的生产效率可以最大化因为感应工作这么快；热开发直接和即时（例如> 1000ºC＜1秒）内的部分。启动几乎是瞬时的，不需要预热或冷却循环。感应加热过程可在冷冷或热成型机旁边的制造车间完成，而不是将零件成批送到远程炉区或分包商。能源效率这个独特的节能过程转换成90%的消耗能量转化为有用的热量；批处理炉一般只有45%节能。由于感应不需要预热或冷却循环，备用热量损失减少到最低限度。控制和自动化过程感应加热消除了不一致和质量问题与明火，火炬加热和其他方法。一旦系统被适当校准和设置，就没有猜测的工作或变化；加热模式是可重复的和一致的。随着GH电源，精确的温度控制提供统一的结果，电源可以瞬间打开或关闭。先进的感应加热系统具有闭环温度控制，能够测量每个部件的温度。可以建立特定的上升、保持和下降速率，并且可以对运行的每个部分记录数据。具有感应的产品质量，被加热的部件不会直接接触到火焰或其他加热元件；热量通过交流电流在零件内部感应。结果，产品翘曲、变形和废品率被最小化。为了达到最大的产品质量，该部件可以在真空、惰性或还原气氛下封闭的腔室中分离，以消除氧化的影响。绿色能源感应加热系统不会燃烧传统矿物燃料；感应是一种清洁、无污染的过程，有助于保护环境。感应系统通过消除烟雾、废热、有害排放物和噪音来改善员工的工作条件。加热是安全和有效的，没有明火危及操作者或模糊过程。非导电材料不受影响，可以靠近加热区而不损坏。使用生长激素的感应加热解决方案意味着提高安装操作和维修，避免生产停工，减少能源消耗和增加零件的质量控制。
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发表于 2017-8-10 09:47:16
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发表于 2017-8-10 14:47:00
