JP5756316B2 - Induction electromagnetic pump for molten metal - Google Patents

Description

  The present invention relates to an induction electromagnetic pump for molten metal used for conveying molten metal such as molten aluminum or molten zinc, and in particular, a core is not disposed at the center of a duct through which molten metal passes, and induction is performed near the side wall of the duct. The present invention relates to an induction electromagnetic pump for molten metal which is provided with a conductor plate for passing an electric current and which maintains the propulsive force of the molten metal in the duct and reduces the flow resistance.

  For example, in the field of casting or the like, an electromagnetic pump for molten metal is used to convey molten aluminum or the like by applying a thrust to the molten metal by electromagnetic induction. Such an electromagnetic pump for molten metal is an induction type electromagnetic type in which a moving magnetic field is generated inside a cylindrical duct by an inductor having a coil wound around a magnetic yoke, and thrust is applied to the molten metal to be supplied. Pumps are mainstream.

Such an induction type electromagnetic pump is described in, for example, Japanese Patent Application Laid-Open No. 2006-341281. FIG. 5 shows a conventional example of the above-described electromagnetic pump for molten metal, and is a general one for conveying molten aluminum or molten zinc.
A hot water supply port is opened in an oblique wall surface 33 near the bottom of the molten metal tank 31 containing the molten metal 32, and the pump side is straight and obliquely upward toward the hot water supply direction via a flange-shaped joint. A duct 21 is connected. Further, a hot water supply side duct 21 ′ bent downward is connected to the pump side duct 21 via joints 25 and 25 ′ such as flange joints. The hot water supply side duct 21 'is pressed against the pump side duct 21 by a spring or the like (not shown), and a heat-resistant gasket inserted between the joints ensures sealing performance. These ducts 21, 21 ′ are made of a heat-resistant and corrosion-resistant material such as silicon nitride and other ceramics, and a heater 29 is wound outside to keep the temperature, and the temperature is equal to or higher than the melting point of the molten metal 32. To be heated.

  An inductor 34 in which a coil 36 is wound around a magnetic yoke 35 is disposed around the pump-side duct 21 on the front side. A core 22 made of a magnetic cylinder is disposed in the pump-side duct 21 so that the central axes thereof coincide with each other. The core 22 is housed in a cylindrical protective tube 23 whose both ends are closed, and is not in direct contact with the molten metal in the pump side duct 21. The protective tube 23 is made of a heat-resistant and corrosion-resistant material such as silicon nitride and other ceramics, and ceramic fibers such as alumina and magnesia or ceramic powder as a cushioning material around the core 22 therein. Filler 28 is filled.

  A flange 26 extends around one end portion of the protective tube 23 near the hot water supply side duct 21 ′, and the joints 25, 25 connect the pump side duct 21 and the hot water supply side duct 21 ′ near the outer periphery of the flange. Is sandwiched between '. Thereby, the core 22 is held so as to be positioned at the center of the pump-side duct 21. The pump side duct 21 and the hot water supply side duct 21 ′ are heated by a heater 29 such as a heat retaining micro heater provided on the outer periphery thereof to prevent the molten metal 32 from solidifying. The flange 26 of the protective tube 23 is provided with a plurality of arc-shaped passage holes 27 that serve as passages for the molten metal 32.

  FIG. 6 shows a conventional example of an immersion type induction electromagnetic pump for annular molten metal. In this type of induction molten electromagnetic pump for molten metal, the inductor 34 is housed in a protective case 37 made of a material having heat resistance and corrosion resistance such as silicon nitride or other ceramics, and almost the entire pump portion is melted. It is immersed in the metal 32. There is a hole for introducing molten metal in the center of the lower end of the protective case 37, and the lower end of the pump side duct 21 is joined to this portion. The molten metal 32 is pumped into the duct 21 from the hole at the lower end of the duct 21. The protective tube 23 is suspended from the connecting portion between the pump side duct 21 and the hot water supply side duct 21 ′ to the height of the inductor 34 by the flange 38. The connecting portion is closed when the vertical lid 39 and the horizontal lid 40 are pressed by a spring (not shown). The core 22 is suspended from the vertical lid 39 to the height of the inductor 34 by a bar 41. In addition, the structure of the electromagnetic pump itself and the connection of the ducts 21 and 21 'are basically the same as those shown in FIG. 5, and the same portions are denoted by the same reference numerals. Since the details overlap, description is omitted.

  In such an induction electromagnetic pump for molten metal, a moving magnetic field is generated on the outer periphery of the tubular duct 21 through which the molten metal flows. Therefore, as described above, the inductor 34 having the coil 36 wound around the yoke 35 is disposed, Inside the duct 21, a magnetic core 22 serving as a magnetic path of a magnetic field generated by the inductor 34 is disposed. The core 22 is covered with a cylindrical protective tube 23 having heat resistance and corrosion resistance in order to prevent corrosion caused by molten metal such as aluminum. Therefore, the flow path of the molten metal is only an annular portion formed between the tubular duct 21 and the protective tube 23. Therefore, this type of electromagnetic pump is called an annular flow channel type molten metal electromagnetic pump. In the case of the molten metal electromagnetic pump described above with reference to FIG. 5, the flow path of the molten metal 32 in the annular portion is further limited to the area of the plurality of arc-shaped passage holes 27 at the flange 26 portion of the protective tube 23. .

  Thus, in the tubular flow path type molten metal electromagnetic pump in which the core 22 is arranged at the center of the duct 21, the flow path of the molten metal 32 in the duct 21 is limited and narrowed. In particular, in the tubular flow channel type molten metal electromagnetic pump of the type described above with reference to FIG. 5, the flow channel of the molten metal 32 in the flange 26 portion of the protective tube 23 is limited to only a plurality of arc-shaped passage holes 27. The cross-sectional area becomes extremely narrow. For this reason, the flow resistance of the molten metal 32 in the duct 21 is large, hindering a smooth flow, and the supply flow rate of the molten metal 32 cannot be increased.

JP 2009-012024 A JP 2009-006364 A JP 2006-341281 A Japanese Patent Application Laid-Open No. 07-204829

  In the present invention, in view of the problems in the conventional molten metal induction electromagnetic pump, the flow path of the duct is not greatly limited, and the flow path cross-sectional area through which the molten metal passes can be widened. An object of the present invention is to provide an induction electromagnetic pump for molten metal that is small in size and can efficiently convey molten metal.

  In the present invention, in order to achieve the above object, the core is not disposed at the center of the duct through which the molten metal passes, the flow resistance in the duct is reduced, and the induced current induced by the moving magnetic field generated by the inductor A conductor plate for passing an induced current is provided near the side wall of the duct.

In other words, the induction electromagnetic pump for molten metal according to the present invention is an induction electromagnetic pump for molten metal having a duct 1 for passing molten metal and an inductor 7 for generating a moving magnetic field in the duct 1. A conductor plate 2 made of a conductive ceramic that does not have a core disposed therein and allows an induced current to flow therethrough is provided corresponding to the position where the inductor 7 is provided in the duct 1 .

  For example, the duct 1 has a substantially rectangular cross section, and the conductor plates 2 and 2 are provided close to a pair of opposing side walls. The inductors 7 and 7 are disposed adjacent to the other pair of opposite side walls of the duct 1 and outside thereof. As the conductor plates 2 and 2, segmented partial cylinders having a shape obtained by vertically dividing a cylindrical conductive ceramic are used. The conductor plates 2 and 2 are arranged close to the inside of the pair of opposing side walls of the duct 1 and fixed to the side walls of the duct 1 with heat-resistant adhesives 9 and 9.

In such an induction electromagnetic pump for molten metal, since it is not necessary to arrange the core at the center of the duct 1, the flow path of the molten metal in the duct 1 is not limited, and the molten metal is widely used in the duct 1. Can be carried. Therefore, the flow resistance of the molten metal can be kept small. The duct 1 is obtained by synthesizing alumina (Al ₂ O ₃ ) and silica (SiO ₂ ) with silicon nitride (Si ₃ N ₄ ) or silicon nitride from the viewpoint of heat resistance, corrosion resistance, and the like. Since it is made of an insulator such as silicon-based ceramics (trade name “Sialon”), the induced current does not flow and the propulsive force of the molten metal is reduced. On the other hand, by providing the conductor plates 2 and 2 made of conductive ceramics that cause the induced current to flow along the flow direction of the molten metal on the side wall of the duct 1, the induced current flows through the conductor plates 2 and 2. Therefore, the propulsion force of the molten metal due to the electromagnetic induction of the inductor 7 can be effectively applied without reducing the propulsion force of the molten metal by the inductor 7.

  As described above, according to the present invention, since it is not necessary to arrange the core at the center of the duct 1, the inside of the duct 1 can be widely used to transport the molten metal, and the flow resistance of the molten metal can be reduced. I can do it. In addition, since an induced current flows through the conductor plates 2 and 2 provided adjacent to the side wall in the duct 1, the propulsion force of the molten metal by the inductor 7 can be effectively applied. Therefore, it is possible to efficiently convey the molten metal.

It is a vertical side view which shows one Example of the induction | guidance | derivation electromagnetic pump for molten metals. It is the sectional view on the AA line of FIG. It is a principal part expanded sectional view which shows a duct part in FIG. It is a vertical side view which shows one use example of the induction | guidance | derivation electromagnetic pump for molten metals. It is a vertical side view which shows the prior art example of the induction | guidance | derivation electromagnetic pump for molten metals. It is a vertical side view which shows the other conventional example of the induction | guidance | derivation electromagnetic pump for molten metals.

In the present invention, in order to achieve the above object, the core is not disposed at the center of the duct through which the molten metal passes, and the induced current induced by the moving magnetic field generated by the inductor is directed in the direction of the molten metal flow in the duct. The conductor for passing along was arrange | positioned in the side wall vicinity in a duct.
Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

1 to 3 show an induction electromagnetic pump for molten metal according to an embodiment of the present invention. As shown in these figures, the duct 1 is composed of silicon nitride ceramics (commodity) obtained by synthesizing alumina (Al ₂ O ₃ ) and silica (SiO ₂ ) with silicon nitride (Si ₃ N ₄ ) or silicon nitride. Made of insulators such as the name “Sialon”). Its cross section is rectangular. As shown in FIGS. 1 and 2, the outside of the duct 1 is covered with an outer cylinder 5.

As is apparent from FIGS. 1 to 3, no core is disposed in the duct 1. Conductor plate 2, 2 formed of a conductive ceramic is provided opposite to the vicinity of the pair of inner wall surfaces facing in the duct 1. The conductor plates 2 and 2 are provided over at least the entire length of an inductor 7 described later. The conductive plates 2 and 2 have a shape in which a cylindrical body made of a conductive ceramic is divided into a plurality of lengths, that is, a segment shape of a cylindrical body made of a conductive ceramic, and are long and curved in an arcuate cross section. It consists of members.

  As shown in FIG. 3, depressions 10 and 10 are provided on both sides of a pair of opposing wall surfaces of the duct 1. The conductive plates 2, 2 are arranged close to both inner side walls of the duct 1 so that the projecting surfaces face each other, and both sides of the conductive plates 2, 2 are formed on a pair of opposing wall surfaces of the duct 1. It fits into the depressions 10 and 10 provided on both sides. Further, heat-resistant adhesives 9 and 9 are filled between the concave side of the conductive plates 2 and 2 and both inner wall surfaces of the duct 1, and are cured to fix the conductive plates 2 and 2 to both inner wall surfaces of the duct 1. doing.

  As shown in FIGS. 1 and 2, a pair of inductors 7 and 7 are arranged on the outside of the duct 1 and its outer cylinder 5 so as to face each other in a direction orthogonal to the direction in which the conductor plates 2 and 2 face each other. Is provided. These inductors 7, 7 are composed of yokes 3, 3 made of laminated iron cores fixed to the outer cylinder 5, and coils 4, 4... Wound around the yokes 3, 3, respectively. These coils 4, 4... Sequentially pass three-phase alternating current, and are wound in multiples of three. In the illustrated example, 3 × 2 = 6 coils 4, 4... Are wound. These coils 4 are fixed by coil holders 8, and both ends of the coil holders 8 are fixedly supported on side plates 6 fixed to both ends of the outer cylinder 5.

  In such an induction electromagnetic pump for molten metal, by passing a three-phase alternating current through the coils 4, 4... Of the inductors 7, 7, the inductors 7, 7 are placed in the longitudinal direction of the duct 1, that is, left or left in FIG. Generate a magnetic field that moves to the right. This magnetic field is generated so as to pass up and down the duct 1 in FIGS. Thus, an induced current is induced in the molten metal in the duct 1 in the right direction (or left direction) in FIG. Accordingly, a propulsive force is generated in the left or right direction in FIG.

  At this time, if the conductive plates 2 and 2 are not provided, the induced current generated in the molten metal in the duct 1 induced by the moving magnetic field flows through the molten metal in both sides of the duct 1 in the vertical direction in FIG. . For this reason, on both sides of the duct, the propulsive force of the molten metal is reduced accordingly. On the other hand, as described above, when the conductor plates 2 and 2 are provided on both sides of the duct 1, current flows on the both sides of the duct 1 in the vertical direction in FIG. 2 through the conductor plates 2 and 2. For this reason, the propulsion of the molten metal is not reduced. Therefore, a propulsive force can be efficiently applied to the molten metal over the entire cross-sectional area of the duct 1. In addition, since there is no core in the duct 1, the cross-sectional area of the duct 1 can be used effectively to the full width where the conductor plates 2 and 2 face each other.

FIG. 4 shows an example of use of the above-described induction electromagnetic pump for molten metal. The molten metal induction electromagnetic pump is housed in a protective case 11 made of ceramic such as silicon nitride and having heat resistance and corrosion resistance. Further, the heat transfer filler 12 made of magnesia (MgO), alumina (Al ₂ O ₃ ) powder or fiber is filled between the yokes 3 and 3 and the coils 4, 4. An induction electromagnetic pump is fixed in the protective case 11. The upper surface opening of the protective case 11 is covered with a heat-resistant and corrosion-resistant cover 18 made of silicon nitride, which is the same as the protective case 11, and the upper end of the duct 1 is protected from the center of the cover 18. 11 to protrude outward.

  The upper end of the duct 1 is connected to a molten metal transport duct 13 via a joint 17, and the duct 15 is further connected to a molten metal transport duct 14. Heaters 15 and 16 are provided in the ducts 13 and 14 for conveying the molten metal, and the ducts 13 and 14 are maintained at a temperature equal to or higher than the melting point of the molten metal.

In such an induction electromagnetic pump for molten metal, the portion covered with the protective case 11 is immersed in the molten metal in the molten metal tank, and the molten metal is introduced into the duct 1. In this state, a three-phase alternating current is applied to the coils 4, 4..., A thrust is applied to the molten metal in the duct 1 to pump it up, and the molten metal is transported to a required location by the ducts 13 and 14.
The above-described induction electromagnetic pump for molten metal is not limited to the so-called immersion type in which the drive portion of the electromagnetic pump is immersed in such molten metal, but the non-immersion type induction for molten metal described above with reference to FIG. Needless to say, it can also be used as an electromagnetic pump.

  The induction electromagnetic pump for molten metal according to the present invention, for example, by casting a casting by supplying molten metal such as molten aluminum into a mold cavity by means of sand casting, low pressure casting, die casting, etc. It can be used as a molten metal conveying means for supplying molten metal such as molten aluminum into the mold cavity.

1 Duct 2 Conductive plate 3 Inductor yoke 4 Inductor coil 7 Inductor 9 Adhesive

Claims (5)

In an induction electromagnetic pump for molten metal having a duct (1) for passing molten metal and an inductor (7) for generating a moving magnetic field in the duct (1), a core is not disposed in the duct (1). An induction electromagnetic pump for molten metal, characterized in that a conductive plate (2) made of a conductive ceramic for passing an induction current is provided in correspondence with the position of the inductor (7) in the duct (1). . The induction electromagnetic pump for molten metal according to claim 1, wherein the duct (1) has a substantially rectangular cross section, and a conductor plate (2) is provided in the vicinity of a pair of opposing side walls. 3. The induction electromagnetic pump for molten metal according to claim 2 , wherein the inductor (7) is arranged adjacent to the other pair of opposite side walls of the duct (1) and outside thereof. The molten metal according to any one of claims 1 to 3, wherein the conductive plate (2) is made of a segmented partial cylindrical shape having a shape obtained by vertically dividing a cylindrical conductive ceramic. Induction electromagnetic pump. The conductor plate (2) is disposed close to the inside of a pair of opposing side walls of the duct (1), and fixed to the side wall of the duct (1) with a heat resistant adhesive (9). An induction electromagnetic pump for molten metal according to any one of claims 1 to 4.

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