JP2009012024A - Electromagnetic pump for molten metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic pump where ducts 1, 1' have sections different in heat radiation quantity, and the sections are individually provided with heaters 9a, 9b, 9c, in which the lead wires of the heaters are easily treated. <P>SOLUTION: Regarding the electromagnetic pump for molten metal, the inside of a part of cylindrical ducts 1, 1' passing through molten metal is provided with an inductor 14 generating a shifting magnetic field, and further, the outer circumference of the ducts 1, 1' is provided with heaters 9a, 9b, 9c heating the molten metal therein to a temperature higher than the melting point thereof. The ducts 1, 1' have a plurality of sections different in heat radiation quantity to the outside, the plurality of sections are respectively provided with different heaters 9a, 9b, 9c, the lead wires 11a, 11b, 11c of the heaters 9a, 9b, 9c are derived from the same place along the ducts 1, 1' and are connected to heating power sources 10a, 10b, 10c. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an induction electromagnetic pump for molten metal used for conveying molten metal such as molten aluminum and molten zinc, and in particular, the duct through which the molten metal passes is long and the heat radiation amount in each part of the duct is different. The present invention relates to an electromagnetic pump for a molten metal in which appropriate heat amounts of heaters for heating a duct in order to maintain a molten state of the molten metal should be different.

  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. In order to generate a moving magnetic field on the outer periphery of a tubular duct through which molten metal flows, an inductor having a coil wound around a yoke is disposed, and a magnetic core serving as a magnetic path of the magnetic field generated by the inductor inside the tubular duct Is arranged. The core is covered with a cylindrical protective tube having heat resistance and corrosion resistance. Therefore, the flow path of the molten metal becomes an annular portion formed between the tubular duct and the protective tube, and this kind of electromagnetic pump is called an annular flow path type electromagnetic pump.

FIG. 7 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 13 near the bottom of the molten metal tank 11 containing the molten metal 12, and the pump side is straight and obliquely upward toward the hot water supply direction through a flange-shaped joint. Duct 1 is connected. Further, a hot water supply side duct 1 ′ bent downward is connected to the pump side duct 1 via joints 5 and 5 ′ such as flange joints. The hot water supply side duct 1 'is pressed against the pump side duct 1 by a spring or the like (not shown), and the joints 5, 5' are inserted by heat resistant gaskets inserted between the joints 5, 5 '. Sealability is ensured. These ducts 1, 1 ′ are made of a heat-resistant and corrosion-resistant material such as ceramic, and a heater 9 is wound on the outside for heat insulation so that the temperature is higher than the melting point of the molten metal 12. It has become.

  Around the pump-side duct 1 on the front side, an inductor 14 in which a coil is wound around a magnetic yoke is disposed. Further, a core 2 made of a magnetic cylinder is disposed in the pump side duct 1 so that the central axes thereof coincide with each other. The core 2 is accommodated in a cylindrical protective tube 3 whose both ends are closed, and is not in direct contact with the molten metal in the pump-side duct 1. The protective tube 3 is made of a heat-resistant and corrosion-resistant material such as ceramic, and a ceramic fiber such as alumina or magnesia or a filler 8 such as ceramic powder is filled around the core 2 therein as a cushioning material. Has been.

  A flange 6 extends around one end of the protective tube 3 near the hot water supply side duct 1 ', and a portion near the outer periphery of the flange 6 connects the pump side duct 1 and the hot water supply side duct 1'; Sandwiched between 5 '. Thereby, the core 2 is held so as to be positioned at the center of the pump-side duct 1. The pump side duct 1 and the hot water supply side duct 1 ′ are heated by a heater 9 made of a heat retaining micro heater or the like provided on the outer periphery thereof to prevent solidification of the molten metal. The flange 6 is provided with a plurality of arc-shaped passage holes 7 serving as passages for the molten metal 12.

  In FIG. 8, the lower end of the pump side duct 1 is inserted into the liquid surface of the molten metal 12 in the molten metal tank 11. In this example, the liquid level of the molten metal 12 does not reach the inductor 14. Therefore, an auxiliary means such as a decompression means is necessary so that the liquid level of the molten metal 12 reaches the inductor 14 during operation. Other than that, it is almost the same as that shown in FIG. Since the details overlap, description is omitted.

  In such a molten metal electromagnetic pump, as shown in FIGS. 7 and 8, the length of the pump side duct 1 and the hot water supply side duct 1 ′ with respect to the pump portion provided with the inductor 14 of the pump side duct 1 is as follows. Is long, it is necessary to provide the heater 9 over the entire section. However, the ducts 1 and 1 ′ have different heat dissipation amounts in their respective portions. Therefore, in order to keep the molten metal in the ducts 1 and 1 ′ at a uniform temperature over the entire length of the ducts 1 and 1 ′, the heat dissipation amounts are respectively determined. The output heater is preferably used individually.

  In general, when the heat radiation amount of each part of the ducts 1 and 1 ′ is different, heating according to the heat radiation amount is performed by changing the heater winding pitch. For example, if the heat dissipation amount in a certain range of the duct is twice the heat dissipation amount in the other range of the duct, the winding pitch of the heater (microheater) is halved so that both have the same temperature.

  However, even when the winding pitch is changed according to the difference in the amount of heat dissipation during normal operation, the temperature rise characteristics of these heaters are different, so it takes a long time to finally apply the electric power during normal operation to reach the same temperature. Heat up slowly, or increase the heater capacity with a margin, attach a thermocouple for control to the part where the temperature rise characteristic is fast, raise the temperature to the set temperature, and then rise later There was no choice but to take a temperature control means to wait until the other part to be heated was heated to the required temperature. Even in the former case, the heater design with only the necessary power for the steady state often fails to raise the temperature or makes the temperature too high if the heat calculation is wrong.

  For this purpose, it is necessary to provide separate heaters for the respective parts of the ducts 1 and 1 ′ and individually set the power output to them. However, in such a case, the number of lead wires increases corresponding to a plurality of heaters.

However, the inductor 14 is fitted in the ducts 1 and 1 ′, particularly on the outer peripheral side of the pump-side duct 1. In order to assemble, maintain and manage the electromagnetic pump for molten metal, the inductor 14 must be attached to and detached from the outer periphery of the pump side duct 1 each time. In this case, there is a problem that if the lead wire comes out from each part of the ducts 1, 1 ′, it takes time to process the lead wire every time the inductor 14 is attached or detached. Furthermore, the wiring of the lead wires becomes complicated, which may cause trouble.
JP 2006-341281 A

  In view of the problems in the conventional molten metal electromagnetic pump described above, the present invention provides a molten metal electromagnetic pump in which there are sections having different heat dissipation amounts in the duct, and a heater is provided in each section. It is an object of the present invention to provide an electromagnetic pump for molten metal that can easily handle the lead wires of the heater when the inductor is attached to and detached from the duct.

  In the present invention, in order to achieve the above object, when the ducts 1 and 1 ′ have a plurality of sections having different heat dissipation amounts with respect to the outside, and the heaters 9a, 9b and 9c are respectively provided in the plurality of sections, The lead wires 11a, 11b, and 11c are led out from the same location along the ducts 1 and 1 ', so that they can be connected to the heating power sources 10a, 10b, and 10c.

  That is, the electromagnetic pump for molten metal according to the present invention is provided with an inductor 14 for generating a moving magnetic field in a part of a cylindrical duct 1, 1 ′ through which molten metal passes, and the part of the duct 1, 1 ′. The core 2 made of a magnetic material that forms the magnetic path of the moving magnetic field generated by the inductor 14 is disposed in the inside, and the molten metal therein is heated to a temperature equal to or higher than the melting point on the outer circumferences of the ducts 1 and 1 ′. Heaters 9a, 9b, 9c are provided. The ducts 1 and 1 'have a plurality of sections with different amounts of heat radiation to the outside, and the heaters 9a, 9b and 9c are provided in the sections, respectively, and lead wires 11a and 11b of the heaters 9a, 9b and 9c are provided. , 11c is led out from the same location along the ducts 1 and 1 'and connected to the heating power sources 10a, 10b and 10c. In this case, the lead wires 11 a of some heaters 9 a are led out between the duct 1 and the inductor 14 along the pump side duct 1.

  In such an electromagnetic pump for molten metal, since different heaters 9a, 9b, 9c are provided in a plurality of sections having different heat radiation amounts to the outside of the ducts 1, 1 ′, the amount of heat corresponding to the heat radiation amount of each section. Can be given individually. The lead wires 11a, 11b and 11c of the heaters 9a, 9b and 9c are led out from the same place along the ducts 1 and 1 'and connected to the heating power sources 10a, 10b and 10c. , 9c lead wires 11a, 11b, 11c can be collectively processed. This facilitates the processing of the lead wires 11a, 11b, and 11c of the heaters 9a, 9b, and 9c when the inductor 14 is attached to and detached from the duct 1 during assembly, maintenance, and management of the molten metal electromagnetic pump.

  As explained above, in the electromagnetic pump for molten metal according to the present invention, in addition to being able to give a heat amount corresponding to the heat radiation amount to a plurality of sections having different heat radiation amounts to the outside of the ducts 1, 1 ′, the duct When the inductor 14 is attached to and detached from the heater 1, the processing of the lead wires 11a, 11b, and 11c of the heaters 9a, 9b, and 9c becomes easy, and assembly, maintenance, and management of the molten metal electromagnetic pump can be easily performed.

In the present invention, different heaters 9a, 9b, 9c are provided in a plurality of sections having different heat radiation amounts to the outside, and the lead wires 11a, 11b, 11c are attached to the ducts 1, 1 'and led out from the same location. It was made possible to connect to the heating power sources 10a, 10b, 10c, and the purpose was achieved.
Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

FIG. 1 shows an embodiment of an external induction electromagnetic pump for molten metal according to the present invention. The configuration of the molten metal induction electromagnetic pump is basically the same as that of the conventional electromagnetic pump described above with reference to FIG. 7, and the same portions are denoted by the same reference numerals.
A hot water supply port is opened in an oblique wall surface 13 near the bottom of the molten metal tank 11 containing the molten metal 12, and a straight pump side duct 1 is connected to the hot water supply port via a flange joint. The hot water supply side duct 1 is inclined so as to gradually become higher in the hot water supply direction on the left side in FIG. 1, and an ascending gradient is formed in the hot water supply direction.

  A hot water supply side duct 1 ′ is connected to the end of the straight pump side duct 1 via joints 5 and 5 ′ such as flange joints. The top of the connection portion between the pump side duct 1 and the hot water supply side duct 1 ′ is closed by a cover plate 19. These ducts 1, 1 'are made of a heat-resistant and corrosion-resistant material such as ceramic. As shown in FIG. 1, the ducts 1 and 1 ′ are wound with heaters 9a, 9b, and 9c made of a heat-retaining microheater provided around the ducts, and the heaters 9a, 9b, and 9c It is heated to a temperature higher than the melting point to prevent solidification due to a temperature drop of the molten metal in the ducts 1 and 1 ′. The heaters 9a, 9b, 9c will be described in detail later.

  In the pump-side duct 1 on the front side, a core 2 made of a cylindrical body made of a magnetic material is disposed so that its central axis coincides. The core 2 is housed in a cylindrical protective tube 3 whose both ends are closed, and is not in direct contact with the molten metal in the pump-side duct 1. The protective tube 3 of the core 2 is made of a heat-resistant and corrosion-resistant material such as ceramic.

  A flange 6 extends around one end of the protective tube 3 near the hot water supply side duct 1 ', and a portion near the outer periphery of the flange 6 connects the pump side duct 1 and the hot water supply side duct 1'; Sandwiched between 5 '. Thereby, the core 2 is held so as to be positioned at the center of the pump-side duct 1. The hot water supply side duct 1 ′ is pressed against the pump side duct 1 by a spring or the like (not shown), and the flange 6 of the protective tube 3 is sandwiched between the joints 5 and 5 ′ by a gasket and the sealing property is secured. Yes.

  Since the protective tube 3 is a molded body of ceramic or the like, it is preferable that the flange 6 is molded integrally with the protective tube 3 rather than providing the flange 6 as a separate member. In the protective tube 3, in order to hold the core 2 in the center of the protective tube 3 and eliminate rattling due to vibration during operation, a filler such as ceramic fiber such as alumina or magnesia or ceramic powder is used as a cushioning material. 8 is filled. As shown in FIG. 1, in the illustrated embodiment, the end of the protective tube 3 is closed by a heat-resistant and corrosion-resistant end plug 4 such as ceramic. The core 2 and the filler 8 are stored and filled in the protective tube 3 by opening the end plug 4.

  A passage 7 for passing molten metal is provided in a portion closer to the inner periphery than a portion near the outer periphery sandwiched between the joints 5 and 5 ′ of the flange 6. This passage 7 is in the shape of a long hole that is long in the circumferential direction. This is a spoke-like connecting part that communicates integrally with the shaped part.

  As shown in FIG. 1, a cylindrical inductor 14 in which a coil is wound around a magnetic yoke is disposed around a portion near the joint 5 of the straight pump-side duct 1 in front. By this inductor 14, a moving magnetic field is formed inside the pump side duct 1, and thrust is given to the molten metal in the pump side duct 1. The magnetic core 2 forms a magnetic path of a moving magnetic field on the central axis of the pump-side duct 1, thereby maintaining the magnetic flux density of the moving magnetic field in the pump-side duct 1, The thrust of the molten metal in the duct 1 is ensured.

  For example, the pump side duct 1 has a portion close to the joint 5 in which the inductor 14 is arranged on the outer periphery as described above, and a portion close to the molten metal tank 11 without the inductor 14, and in these portions, from the outer peripheral surface. The heat dissipation is different. Further, the hot water supply side duct 1 ′ does not have the inductor 14, and the heat radiation amount is different from that of the pump side duct 1. Therefore, in the example shown in the figure, the pump side duct 1 is divided into three sections: a portion near the molten metal tank 11 without the inductor 14, a portion near the joint 5 where the inductor 14 is disposed, and a hot water supply side duct 1 ′. Another heater 9a, 9b, 9c is arranged individually.

  FIG. 2 differs from the example of FIG. 1 in that the pump side duct 1 is placed above the liquid level of the molten metal 12 and the lower end of the pump side duct 1 is immersed from the liquid level of the molten metal 12 below the molten metal. For electromagnetic pumps. In the example of FIG. 1, the pump side duct 1 is erected vertically, but the pump side duct 1 may be disposed obliquely. In any case, in this type of molten metal electromagnetic pump, since there is no liquid level of the molten metal 12 at the position of the inductor 14, the pump side duct 1 is depressurized by a vacuum pump or the like, and the molten metal 12 is pumped up by atmospheric pressure. In this state, it is necessary to carry out a pumping operation of molten metal by a pump. Other than that, it is the same as FIG. Since these are redundant, the description thereof is omitted.

  Even in this molten metal electromagnetic pump, the pump-side duct 1 has a portion close to the joint 5 in which the inductor 14 is disposed on the outer periphery, and a portion close to the molten metal 12 without the inductor 14. There is a hot water supply side duct 1 ′. These parts have different heat dissipation amounts. Therefore, also in the example shown in FIG. 2, the pump side duct 1 has a portion near the molten metal tank 11 without the inductor 14, a portion near the joint 5 where the inductor 14 is disposed, and the hot water supply side duct 1 ′. Different heaters 9a, 9b, 9c are individually arranged in one compartment.

FIG. 3 schematically shows a state in which the heaters 9a, 9b, and 9c are individually arranged. For convenience, the pump side duct 1 and the hot water supply side duct 1 ′ are shown side by side in a line. A plurality of induction-wound heaters 9a, 9b, 9c are individually arranged in the respective sections where the heat dissipation amounts of the ducts 1, 1 ′ are different, but their lead wires 11a, 11b, 11c are connected to the ducts 1, 1 ′. They are pulled out together and are all led to the same location. For example, the lead wire 11 a of the heater 9 a on the lower end side (right side in FIG. 3) where the inductor 14 of the pump side duct 1 does not exist passes between the inductor 14 and the pump side duct 1 along the pump side duct 1. It is drawn out toward the hot water supply side duct 1 ′. By doing so, troublesome processing of the lead wires 11a, 11b, and 11c becomes unnecessary when the inductor 14 is attached to and detached from the pump-side duct 1.
In the embodiment of FIG. 4, the lead wire 11 a of the heater 9 a is drawn straight, but it can also be drawn out by being wound around the pump side duct 1.

  As shown in FIG. 3, the lead wires 11a, 11b, 11c of the plurality of heaters 9a, 9b, 9c are connected to heating power sources 10a, 10b, 10c. By connecting the heating power sources 10a, 10b, and 10c individually to the plurality of heaters 9a, 9b, and 9c via the lead wires 11a, 11b, and 11c, the heating power corresponding to the heat radiation amount of each part of the ducts 1 and 1 ′ is obtained. Can be supplied separately. Moreover, since the heating power supplies 10a, 10b, and 10c can be connected to the lead wires 11a, 11b, and 11c drawn from the same direction, the wiring process becomes easy.

FIG. 4 is an example in which the plurality of heaters 9a, 9b, and 9c of FIG. is there.
Further, FIG. 5 shows a non-inductive winding state in which a plurality of heaters 9a, 9b, and 9c are folded in two, and according to the heat radiation amount while changing the pitch to each section where the heat radiation amounts of the ducts 1 and 1 ′ are different. This is an example of continuous arrangement.

  FIG. 6 shows a case where the pitch is changed as in the embodiment of FIG. 5, but a plurality of heaters are inductively wound. Generally, the heating capacity of the duct 1 near the molten metal tank 11 is small because the heat is supplied through the molten metal, so that the heater 9a can have the smallest heating capacity. To do. The portion where the inductor 14 of the electromagnetic pump 14 of the duct 1 is disposed has the largest amount of heat radiation, and is therefore wound in three strips. The hot water supply side duct 1 'has two nozzles because the nozzle is open and the heater is not wrapped around it, so the heat radiation is the second smallest.

  In the operation method of the molten metal electromagnetic pump according to the present invention, the heaters 9a, 9b, and 9c can supply the heat corresponding to the heat radiation amount of each part of the ducts 1 and 1 ', and lead of the heaters 9a, 9b, and 9c. Since the processing of the wires 11a, 11b, and 11c is also easy, the inductor 14 can be easily attached to and detached from the pump-side duct 1.

It is sectional drawing which shows one Example of the induction | guidance | derivation electromagnetic pump for external ring-shaped molten metals by this invention. It is sectional drawing which shows the other Example of the induction | guidance | derivation electromagnetic pump for the external ring-shaped molten metal by this invention. It is the figure which showed typically the state which arrange | positioned the heater with the equal pitch of induction winding to each part of a duct in the said Example separately. In the said Example, it is the figure which showed typically the state which arrange | positioned the heater with equal pitch which made the non-inductive winding by folding the heater into two in each part of the duct. In the said Example, it is the figure which showed typically the state which has arrange | positioned the heater from which the pitch which made the non-inductive winding by folding a heater into two in each part of a duct separately was arrange | positioned. It is the figure which showed typically the state which has arrange | positioned separately the heater from which the pitch of induction winding differs in each part of the duct in the said Example. It is sectional drawing which shows the prior art example of the induction | guidance | derivation electromagnetic pump for an external form annular molten metal. It is sectional drawing which shows the other prior art example of the induction | guidance | derivation electromagnetic pump for external molten metal for cyclic | annular molten metals.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pump side duct 1 'Hot water supply side duct 2 Core 9a Heater 9b Heater 9c Heater 10a Heater power supply 10b Heater power supply 10c Heater power supply 11a Heater lead wire 11b Heater lead wire 11c Heater lead wire 12 Molten metal 14 Inductor

Claims (2)

An inductor (14) for generating a moving magnetic field is provided in a part of the cylindrical ducts (1) and (1 ') through which the molten metal passes, and the inside of the part of the ducts (1) and (1') The core (2) made of a magnetic material that forms the magnetic path of the moving magnetic field generated by the inductor (14) is disposed on the outer periphery of the duct (1), (1 ') In the electromagnetic pump for molten metal provided with heaters (9a), (9b) and (9c) for heating to a temperature equal to or higher than the melting point, the ducts (1) and (1 ′) have a plurality of sections with different amounts of heat radiation to the outside. The heaters (9a), (9b), (9c) are provided in the plurality of sections, and lead wires (11a), (11b), (9c) of the heaters (9a), (9b), (9c) are provided. 11c) is led out from the same location along the ducts (1) and (1 '), and the heating power source (10a , (10b), an electromagnetic pump for molten metal, characterized in that connected to (10c). The lead wire (11a) of a part of the heater (9a) is led out between the duct (1) and the inductor (14) along the pump side duct (1). An electromagnetic pump for molten metal as described in 1.

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