一、概述、

感应电流和磁场作用产生电磁推力，因为该推力沿行波磁场方向作用并且具有水平分量和垂直分量，可使铝熔液作倾斜向上或者相下流动，起到搅拌的作用，这种现象被称为电磁搅拌。其重要目的是混合金属溶液，以产生更好的均质合金。

搅拌的总量决定于炉子的大小，加入金属溶液的功率，电磁场的频率以及炉内金属熔的种类和质量。搅拌的缺点是它会使炉的耐火炉衬，因搅动金属熔液碰撞在炉壁上而渐渐地出现磨损。渐渐磨损的结果就要求定期更换炉衬。 当炉衬已被磨损到其规定的最小厚度时， 为了防止炉衬失效， 应迅速更换。

优点为具有对被熔化溶液有搅拌作用,使溶液更均勻混合。可使熔体上下部的温度均匀，搅拌过程不破坏氧化层，可减少熔体的吸氢及吸氧，确保熔体质量，实现复杂合金的成分均匀化。电磁搅拌是靠电磁力对金属熔液非接触的搅拌，不存在搅拌过程中对熔体的污染。

二、功能的实现原理：采用2组线圈实现上下搅拌，任何搅拌状态下搅拌强度、搅拌时间，搅拌方向，单个线圈的工作时间、都可以在熔炼控制系统内设定，并实现精准的PID温度控制。

三、智能控制系统说明

智能控制系统可以对中频加热设备和机械装置进行集中控制，它置于生产现场，有利于对加热工艺的全过程进行控制。在此基础之上，配置有接触式测温装置（热电偶）与PLC编程模块，可以实现根据铝熔液温度控制和中频电源功率控制,以及搅拌强度、搅拌时间，搅拌方向的控制。

四、PID温度闭环控制系统

   采用国际先进的PID温度闭环控制系统，热电偶测温，温度精度±５℃。

五、感应线圈说明

感应线圈用铜管绕成。为了保证感应线圈的可靠性，铜管采用了5mm厚,纯度为99.99%，材质为T2的优质冷挤制铜管。感应线圈的形状和空间结构根据电磁感应数值模拟优选的结果来设计。2个线圈顺时针逆时针绕制。（采用正反绕制避免了线圈之间的缝隙过大产生漏磁）

感应器由水冷铜管、耐火层、保护层等结构组成，其匝数结构通过ANSYS模拟优化得到，来满足变频的需要。

六、炉体的设计要求

定点炉体说明

    炉体部份包括感应加热线圈、结构主体碳钢、加磁轭，绝缘体、耐热绝热材料、支承框架、定点浇铸结构等。　

炉体定点浇铸结构安装在支承框架上，根据甲方提供的雾化中间包及雾化炮台尺寸，设计炉体和液压倾炉机构。此炉体运行速度均匀，炉咀的高差小，出液连续稳定。炉咀的运行曲线，由固定的轨迹，并由电脑优化运算，使用特殊的曲线模板导向锁定，使炉体从连续出液到定点出液均匀有序进行。炉体倾转角度：0～95°（0°指炉口为水平位置）；炉翻转稳定性高，出料口定位精度高（熔炼炉出炉口与漏包的距离小于50mm），浇注中心变动误差小，雾化浇钢时炉嘴无前后运动，定点浇注精度高，，前后误差不超过30mm，同时保证了金属液流的稳定。成套设备维护更换均采用模块化设计，易维护易检修，很大程度提高生产效率。坩埚或打结料的选择美国天津联矿的产品能够耐氟盐腐蚀以及液态铝合金冲刷；且不得污染炉内金属。

1. Overview:

Sensing current and magnetic field generate electromagnetic force, because the thrust force acts in the direction along a traveling wave magnetic field and has a horizontal component and a vertical component, the molten aluminum can be inclined upward or fluidized phase, play the role of stirring, a phenomenon It is called electromagnetic stirring. Its important purpose is to mix metal solutions to produce a better homogeneous alloy.

The total amount of agitation depends on the size of the furnace, the kind and quality of the metal solution is added to the power of the furnace and molten metal frequency electromagnetic field. The disadvantage of agitation is that it causes the refractory lining of the furnace to gradually wear out due to the agitation of the molten metal colliding on the wall of the furnace. The result of wear and tear requires regular replacement of the lining. When the lining has been worn to its specified minimum thickness, it should be replaced quickly in order to prevent lining failure.

The advantage is that it has a stirring effect on the melted solution to make the solution more uniformly mixed . The temperature of the upper and lower parts of the melt can be made uniform, the stirring process does not destroy the oxide layer, the hydrogen absorption and oxygen absorption of the melt can be reduced, the melt quality can be ensured, and the composition of the complex alloy can be homogenized. Electromagnetic stirring is the non-contact stirring of the molten metal by electromagnetic force, and there is no contamination of the melt during the stirring process.

2, the implementation principle function of electromagnetic stirring electric furnace: 

using two sets of coils to achieve vertical stirring, stirring in any stirring intensity, the stirring time, stirring direction, the working time of a single coil, can be set within the control system melting, and to achieve accurate temperature PID control.

3 , the intelligent control system description

The intelligent control system can centrally control the intermediate frequency heating equipment and mechanical devices. It is placed on the production site, which is beneficial to control the whole process of the heating process. On this basis, the contact temperature measuring device ( thermocouple ) and the PLC programming module are arranged , which can realize the control according to the aluminum melt temperature control and the intermediate frequency power control , as well as the stirring intensity , the stirring time and the stirring direction .

4, PID temperature closed-loop control system

Adopt international advanced PID temperature closed-loop control system, thermocouple temperature measurement, temperature accuracy ± 5 °C.

5, induction coil description

The induction coil is wound with a copper tube. In order to ensure the reliability of the induction coil, the copper tube adopts a high-quality cold-extruded copper tube with a thickness of 5 mm and a purity of 99.99% and a material of T2. The shape and spatial structure of the induction coil are designed according to the preferred results of electromagnetic induction numerical simulation. The 2 coils are wound clockwise counterclockwise . (The use of forward and reverse winding to avoid excessive gap between the coils to generate magnetic leakage)

The inductor consists of a water-cooled copper tube, a refractory layer, a protective layer, etc., and its number of structures is optimized by ANSYS simulation to meet the needs of frequency conversion.

6, the design requirements of the furnace body

Fixed furnace description

The furnace body part includes an induction heating coil, a structural body carbon steel, a yoke, an insulator, a heat-insulating material, a support frame, a fixed-point casting structure, and the like.

The fixed-point casting structure of the furnace body is installed on the supporting frame, and the furnace body and the hydraulic tilting furnace mechanism are designed according to the size of the atomizing tundish and the atomizing turret provided by the party A. The furnace body runs at a uniform speed, the height difference of the nozzle is small, and the liquid discharge is continuously stable. The running curve of the nozzle is fixed by the trajectory and optimized by the computer. The special curved template is used to guide the locking, so that the furnace body is uniformly and orderly discharged from the continuous liquid discharge to the fixed point. The tilting angle of the furnace body: 0～95° (0° refers to the horizontal position of the furnace mouth); the furnace has high stability of turning, and the positioning accuracy of the discharging port is high (the distance between the outlet and the leakage of the melting furnace is less than 50mm), and the pouring center changes. The error is small. When the atomized steel is poured, there is no back and forth movement of the nozzle. The precision of the fixed point casting is high, and the front and back error does not exceed 30mm, and the stability of the metal liquid flow is ensured. The maintenance and replacement of complete sets of equipment are modular in design, easy to maintain and easy to overhaul, greatly improving production efficiency. Choice of crucible or knotting The products of Tianjin United Mine are resistant to fluoride salt corrosion and liquid aluminum alloy scour; and must not contaminate the furnace metal .

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