Metal melting furnace provided with electromagnetic stirring device

Abstract

To provide a metal melting furnace provided with an electromagnetic stirring device capable of improving melting efficiency through stirring molten metal in the metal melting furnace.SOLUTION: A metal melting furnace is provided with: a melting furnace body 11; a melting furnace lid 21 provided with heating means 20 on its upper part; and an electromagnetic stirring device 30 arranged on its lower part to stir molten metal in the melting furnace body. The electromagnetic stirring device is provided with lifting means arranged on a bottom part of the melting furnace body to face to each other to stir molten metal by flowing it by applying a rotational magnetic field to molten metal 11b in the melting furnace body, and capable of changing a distance to the bottom part of the melting furnace body. Further, the electromagnetic stirring device is provided with two stators arranged linearly and facing to each other on the bottom part of the melting furnace body to generate a spiral force in the molten metal in the melting furnace body by generating a moving magnetic field in reverse directions Y1, Y3 by applying electric current to coils wounded around E core iron cores of the stators.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a metal melting furnace equipped with an electromagnetic stirring device that is installed at the bottom of the metal melting furnace and that can stir the molten metal in the metal melting furnace by applying a moving magnetic field to the molten metal in the metal melting furnace to cause it to flow, thereby increasing melting efficiency. [Background technology]

[0002] A known conventional metal melting furnace for casting is one in which a material inlet is provided in the furnace body so that the molten metal circulates, and the raw materials are introduced into the molten metal, which is swirled by an electromagnetic stirring device, to melt the raw materials.

[0003] For example, Patent Document 1 describes a metal melting furnace into which raw materials (such as chip or powder processing materials made of aluminum, etc.) can be introduced and melted, The publication describes a metal melting furnace equipped with an electromagnetic stirring device that stirs the molten metal by creating a vortex.

[0004] However, in such conventional metal melting furnaces, the range of the vortex that can be generated by the electromagnetic stirring device is narrow, and even when the melting raw materials are added, they are not caught in the molten metal and remain floating on the surface of the molten metal, resulting in insufficient melting action. The present invention has been developed in consideration of the above circumstances, and its object is to provide a metal melting furnace equipped with an electromagnetic stirring device that can increase the stirring force of the molten metal. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-10214 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been developed in view of the above-mentioned conventional techniques, and its object is to provide a metal melting furnace equipped with an electromagnetic stirring device that can strengthen the stirring force of the molten metal. [Means for solving the problem]

[0007] (1) The metal melting furnace equipped with the electromagnetic stirring device of the present invention is A melting furnace body 11, a melting furnace lid 21 provided with a heating means 20 on its top; an electromagnetic stirring device 30 below the furnace for stirring the molten metal 11b in the furnace body; It is equipped with The electromagnetic stirring device 30 is It is disposed facing the bottom 11a of the melting furnace body 11, A rotating magnetic field is applied to the molten metal 11b in the melting furnace body to cause the molten metal 11b to flow, thereby stirring the molten metal 11b. The melting furnace is characterized by being provided with an elevating means 31 capable of varying the distance from the bottom 11a of the melting furnace body 11. (2) The metal melting furnace equipped with the electromagnetic stirring device of the present invention is as described above, The electromagnetic stirring device 30 is Facing the bottom 11a of the melting furnace body 11, Two stators are arranged in a straight line. By applying a current to the coil wound around the E-core of the stator, moving magnetic fields are generated in opposite directions Y1 and Y3, A feature of the present invention is that a vortex force is generated in the molten metal in the melting furnace body 11. (3) The metal melting furnace equipped with the electromagnetic stirring device of the present invention is as described above, Furthermore, a detection means 40 is provided for detecting the stirring state of the molten metal in the melting furnace body 11, The electromagnetic stirring device 30 is characterized in that it is controlled to move up and down in accordance with the value detected by the detection means 40. [Effects of the Invention]

[0008] According to the present invention, A metal melting furnace equipped with an electromagnetic stirring device can apply a rotating magnetic field to the entire molten metal in the metal melting furnace, generating a vortex force and causing the molten metal to flow. In addition, an electromagnetic stirring device that can be raised and lowered is provided at the bottom of the melting furnace, making it possible to control the stirring state of the molten metal in the metal melting furnace. In the present invention, an electromagnetic induction stirring device 30 is installed at the bottom of the melting furnace body 11, instead of the conventional method of stirring the molten metal 11b by inserting an impeller into the molten metal 11b. Therefore, there is no problem of impurities being drawn in from the impeller. Furthermore, there is no need to water-cool the impeller, so there is no risk of explosion due to water coming into contact with the molten metal. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a front view showing a metal melting furnace according to an embodiment of the present invention; [Figure 2] 1 is a plan view showing a metal melting furnace according to an embodiment of the present invention; [Figure 3] FIG. 2 is a left side view showing the metal melting furnace according to the embodiment. [Figure 4] FIG. 2 is an explanatory diagram showing a lifting means for the metal melting furnace according to the embodiment. [Figure 5] FIG. 1 is an explanatory diagram showing a state in which a coil is wound around an E-core iron core used in an electromagnetic stirring device. [Figure 6] FIG. 2 is a plan view showing the arrangement of stators in the electromagnetic stirring device. DETAILED DESCRIPTION OF THE INVENTION

[0010] The metal melting furnace 10 equipped with the electromagnetic stirring device of the present invention is The melting furnace comprises a melting furnace body 11, a melting furnace cover 21 provided with a heating means 20 on the top thereof, and an electromagnetic stirring device 30 for stirring the molten metal 11b in the melting furnace body 11 on the bottom thereof. The electromagnetic stirring device 30 is It is disposed opposite the bottom 11a of the melting furnace main body 11, and can agitate the molten metal 11b in the melting furnace main body by applying a rotating magnetic field to the molten metal 11b to cause it to flow. That is, two stators are provided in a straight line, By applying current to the coil wound around the E-core of the stator, The moving magnetic fields are generated in opposite directions Y1 and Y3, A vortex force is generated in the molten metal in the melting furnace body 11. The distance from the bottom 11a of the melting furnace main body 11 can be changed by the lifting means 31. The metal melting furnace is equipped with a detection means 40 for detecting the stirring state of the molten metal in the melting furnace body 11, The elevation of the electromagnetic stirring device 30 is controlled in accordance with the value detected by the detection means 40.

[0011] Hereinafter, a metal melting furnace 10 according to an embodiment of the present invention will be specifically described with reference to the drawings.

[0012] <Metal melting furnace 10> As shown in Figures 1 to 6, the metal melting furnace 10 of this embodiment includes a melting furnace body 11, a melting furnace lid 21 equipped with a heating means 20 on the upper side thereof, and an electromagnetic stirring device 30 on the lower side thereof for stirring the molten metal 11b in the melting furnace body 11.

[0013] <Melting furnace body 11> The melting furnace body 11 is a container for storing melted raw materials as molten metal. In this embodiment, the molded article is formed into a rectangular parallelepiped shape using monolithic refractory material.

[0014] <Melting furnace lid 21> The melting furnace lid 21 is placed on the top surface of the melting furnace body 11, and the inside of the frame of the melting furnace lid 21 is covered with a heat-resistant board or the like, and the heating means 20 is disposed inside the board. In addition, a plurality of hanging fittings 22 are attached to the upper surface of the melting furnace lid 21, and by hooking a hook onto these hanging fittings 22 from above and lifting them up, the melting furnace lid can be removed from the top of the melting furnace body 11. This allows the heater to be replaced and cleaned, and also makes it easy to perform maintenance such as cleaning and repair of the melting furnace body 11. The melting furnace lid 21 does not cover the entire top of the melting furnace body 11, but rather has an open top in part (the right side in the plan view of Figure 2) as a raw material charging chamber 10a for charging raw materials, etc. As shown on the left side of the plan view of FIG. 2, a pumping chamber 10b for pumping out the molten metal is provided. The pumping chamber 10b is provided with a temperature sensor 10c (for example, a thermocouple) so that the temperature of the molten metal can be monitored.

[0015] <Heating means 20> Furthermore, inside the melting furnace lid 21, a heating means 20 is attached facing the melting furnace body 11 for heating and melting the raw materials. The heating means 20 may be an electric heater made of nichrome wire, SiC, or the like. In this embodiment, six rod-shaped electric heaters 21a are arranged inside the melting furnace lid 21 as shown in the drawing. The six rod-shaped electric heaters 21a are arranged horizontally at approximately equal intervals across the width of the melting furnace body 11, and can uniformly heat and melt the raw materials in the melting furnace body 11 from the open bottom surface. Although a gas burner can be used as the heating means 20, there is a disadvantage in that the residual oxygen in the flame emitted from the gas burner reacts with the molten metal to form oxides, which can adhere to the inner walls of the melting furnace body 11 and damage the furnace body, or get mixed into the molten metal and become impurities. Therefore, in this embodiment, an electric heater is used.

[0016] <Temperature sensor 10c> A temperature sensor 10c such as a thermocouple for detecting the temperature of the molten metal in the melting furnace body 11 is disposed inside the melting furnace lid 21, so that information about the molten metal can be obtained. In addition, by placing a temperature sensor 10c in the pumping chamber 10b, the temperature of the molten metal just before pumping can also be grasped, and based on the temperature information from each of these temperature sensors, the heating means 20 can be controlled to maintain the molten metal in the melting furnace body 11 at a predetermined temperature.

[0017] <Electromagnetic Stirring Device 30> The electromagnetic stirring device 30 is This is a stirring means for applying a moving magnetic field to the molten metal to cause it to flow, and as shown in the figure, it is installed on the outside of the bottom of the melting furnace body 11 that holds the molten metal. In this embodiment, the electromagnetic stirring device 30 applies the principle of a linear motor. A three-phase AC (U-phase, V-phase, and W-phase) is applied to the linear stator 32 while shifting the phases sequentially to generate a moving magnetic field, This moving magnetic field causes the rotor (corresponding to the molten metal in the furnace) to act as if it were the secondary conductor of an induction motor. That is, the moving magnetic field generated by the stator 32 is applied as a rotational thrust (Lorentz force) to the molten metal in the melting furnace body, and the rotating magnetic field is applied to generate a vortex.

[0018] <Stator 32> As shown in FIG. 5, the stator 32 is The component is an E-core iron core 33 made by laminating a plurality of thin electromagnetic steel sheets that have been punched out by press. The E-core iron core 33 is a member formed to resemble the shape of the letter "E" of the alphabet. It consists of a base 33a and an extension 33b extending upward from the base 33a, A copper wire coil 34 was wound around the extending portion 33b to form the stator 32. In addition, as the silicon content of the electromagnetic steel sheet used as the material for the E-core iron core 33 increases, the saturation magnetic flux density and workability decrease, so it is desirable to use steel containing approximately 3.2% silicon, which can sufficiently reduce iron loss without significantly deteriorating either of these properties.

[0019] <Arrangement of stator 32> In this embodiment, the stators 32 are arranged in two linear rows (32a, 32b) so that the tips 33c of the extension portions 33b of the E-core iron cores 33 face upward and face the bottom 11a of the melting furnace body 11 (see Figure 3).

[0020] As shown in Figure 6(a), When a three-phase AC current is applied to the stators 32a and 32b arranged in two linear rows so that the magnetic fields move in opposite directions, The stators generate magnetic fields (moving magnetic fields) that move in the opposite directions Y1 and Y3, respectively. This moving magnetic field applies a rotational force to the molten metal 11b in the melting furnace body. In this embodiment, A copper coil is wound around the extension 33b of the E-core iron core 33 (number of coil turns: 385 tunes) to form the stator 32. Frequency: 0.5 to 1.0 Hz Current: 150 to 340 Arms was applied to generate a moving magnetic field.

[0021] In FIG. 6(a), two rows of stators 32a and 32b are arranged in a straight line. Three-phase alternating current was passed so that the magnetic fields would move in opposite directions. As shown in Figure 6(b), When the four stators 32 are arranged with their longitudinal directions rotated by 90° each and a three-phase AC current is applied to the stators 32, In the stator 32, moving magnetic fields are generated in the directions of W1, W2, W3, and W4, respectively. It is also possible to apply a stronger rotational force to the molten metal 11b in the melting furnace body.

[0022] <Lifting means 31> As shown in Figure 4, The electromagnetic stirring device 30 disposed at the bottom 11 a of the melting furnace body 11 can be moved up and down by the lifting means 31 . In other words, by raising and lowering the electromagnetic stirring device 30 and changing the distance from the bottom 11a of the melting furnace body 11, the stirring force exerted on the molten metal 11b can be adjusted as desired, and a stirring effect according to the dimensions and shape of the melting furnace body 11 can be obtained. Furthermore, by lowering the electromagnetic stirring device 30 to secure a gap, maintenance, inspection, and repair of the furnace bottom of the melting furnace body 11 and the electromagnetic stirring device can be facilitated. As the lifting means 31, a member such as a screw, hydraulic, air cylinder, or link mechanism attached to a frame on the top surface of the electromagnetic stirring device 30 can be used. For example, the lower part of the electromagnetic stirring device 30 is attached to the upper end of the rod of an air cylinder that can be extended and retracted up and down, and the air cylinder can adjust the distance between the electromagnetic stirring device 30 and the bottom 11b of the melting furnace body 11 by extending and retracting the rod.

[0023] In addition, the electromagnetic stirring device 30 can also be raised or lowered to a height that generates the most efficient degree of stirring when the control unit (not shown) receives a detection signal from a stirring detection means (not shown) for the molten metal 11b. In addition, metal melting furnaces Furthermore, a detection means 40 for detecting the stirring state of the molten metal in the melting furnace body 11 may be provided, and the elevation of the electromagnetic stirring device 30 may be controlled according to the value detected by the detection means 40. The stirring detection means may be visual inspection, a camera, image processing, or the like. Since the metal melting furnace of this embodiment is configured as described above, the raw aluminum is heated and melted in the metal melting furnace using an electric heater or the like, and is stirred by an electromagnetic stirring device to maintain the predetermined temperature. [Industrial Applicability]

[0024] The metal melting furnace equipped with the electromagnetic stirring device of the present invention has an electromagnetic stirring device with an E-core arranged in a straight line at the bottom of the melting furnace that can be raised and lowered, and a rotating magnetic field can be applied to the molten metal in the metal melting furnace to generate a vortex force and cause it to flow, making it possible to control the stirring state of the molten metal and making it highly applicable and workable in industry. [Explanation of symbols]

[0025] 10 Metal melting furnace 10a Raw material input room 10b Pumping room 10c Temperature Sensor 11 Melting furnace body 11a bottom 11b Molten metal 20 Heating means 21 Melting furnace lid 21a Electric heater 22 Hanging hardware 30 Electromagnetic Stirring Device 31 Lifting means 32 Stator 33 E-core iron core 33a base 33b Extension 33c Tip of extension 34 Coil of Copper Wire 40 Detection methods Y1, Y3 moving magnetic field W1, W2, W3, W4 Moving magnetic field

Claims

1. A melting furnace body; a melting furnace lid provided with a heating means on its top; an electromagnetic stirring device below the furnace for stirring the molten metal in the furnace body; It is equipped with The electromagnetic stirring device is It is placed opposite the bottom of the melting furnace body, A rotating magnetic field is applied to the molten metal in the melting furnace body to cause the molten metal to flow, thereby stirring the molten metal, and The melting furnace is characterized by having an elevating means capable of varying the distance from the bottom of the melting furnace body. A metal melting furnace equipped with an electromagnetic stirrer.

2. The electromagnetic stirring device is Facing the bottom of the melting furnace body, Two stators are arranged in a straight line. By applying a current to the coil wound around the E-core of the stator, moving magnetic fields are generated in opposite directions Y1 and Y3, A vortex force is generated in the molten metal in the melting furnace body. A metal melting furnace equipped with the electromagnetic stirring device according to claim 1.

3. The metal melting furnace is Further, a detection means for detecting the stirring state of the molten metal in the melting furnace body is provided, 3. A metal melting furnace equipped with an electromagnetic stirring device according to claim 1, wherein the raising and lowering of the electromagnetic stirring device is controlled in accordance with the value detected by the detection means.

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