Non-iron metal dissolution methods

Abstract

To provide a nonferrous metal melting method with high efficiency.SOLUTION: A circulation type nonferrous metal melting furnace 1 is configured to: form a circulation passage of molten metal by juxtaposing a first temperature rise chamber 12 having a plurality of first electric heaters 30 and a second temperature rise chamber 13 having a plurality of second electric heaters 40 while sandwiching an intermediate wall 15; provide an input port 11 for a nonferrous metallic material on one end side of the intermediate wall 15 between the first temperature rise chamber 12 and the second temperature rise chamber 13; cause the other end side of the intermediate wall 15 to communicate with a molten metal delivery chamber 14 from which molten metal can be taken out; perform temperature control in each of the first temperature rise chamber 12 and the second temperature rise chamber 13; and circulate the molten metal via a circulation pump 20 provided in the second temperature rise chamber 13. In a method for melting the nonferrous metallic material by using the circulation type nonferrous metal melting furnace, rotational frequency of the circulation pump 20 is increased as an input amount per unit time of the nonferrous metallic material increases.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a non-ferrous metal melting method for melting non-ferrous metals such as aluminum alloys while circulating molten metal for the purpose of using it in the production of various cast products such as die-cast casting.

Background Art

[0002] Conventionally, for melting non-ferrous metals such as aluminum alloys, melting furnaces using radiant flames from burners using fossil fuels such as petroleum and natural gas have been mainly adopted. However, since the radiant flames from burners using fossil fuels have problems in terms of thermal efficiency and the environment, improvement measures have been demanded.

[0003] As an improvement measure, a non-ferrous metal melting furnace with a structure in which an electric heater is immersed in molten metal has been disclosed (see, for example, Patent Document 1). As shown in FIG. 3, the non-ferrous metal melting furnace 50 described in this Patent Document 1 is provided with a plurality of chambers including a melting chamber 51, a heating chamber 52, and a dross removal chamber 53. The non-ferrous metal material charged into the melting chamber 51 is melted by an electric heater 56 provided in the heating chamber 52 and heated to a predetermined temperature, and then supplied from there to a hot water chamber 55 through a calming chamber 54. The molten metal circulates from the dross removal chamber 53 to the heating chamber 52, but no electric heater is provided in this dross removal chamber 53.

[0004] Since this non-ferrous metal melting furnace 50 uses an electric heater to melt and heat the non-ferrous metal material, it has a great advantage of being excellent in terms of thermal efficiency and the environment compared to the conventional melting furnace using a burner.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the inventors were not satisfied with this situation and continued their research and development, eventually developing a circulating non-ferrous metal melting furnace that can more efficiently melt and heat non-ferrous metal materials in order to miniaturize the device. Furthermore, by focusing on the temperature and flow rate of the molten metal obtained using this circulating non-ferrous metal melting furnace, we were able to develop an even more efficient method for melting non-ferrous metals.

[0007] Therefore, the object of the present invention is to provide a non-ferrous metal dissolution method that can efficiently dissolve and heat non-ferrous metal materials. [Means for solving the problem]

[0008] To achieve the above objective, the present invention provides a non-ferrous metal melting method that uses a circulating non-ferrous metal melting furnace (1) configured to melt the non-ferrous metal material by arranging a first heating chamber (12) equipped with a plurality of first electric heaters (30) and a second heating chamber (13) equipped with a plurality of second electric heaters (40) side by side with an intermediate wall (15) in between, forming a circulation path for molten metal, providing an inlet (11) for non-ferrous metal material at one end of the intermediate wall (15) between the first heating chamber (12) and the second heating chamber (13), and connecting the other end of the intermediate wall (15) to a tapping chamber (14) from which molten metal can be removed, and controlling the temperature in each of the first heating chamber (12) and the second heating chamber (13), and circulating the molten metal via a circulation pump (20) provided in the first heating chamber (12) or the second heating chamber (13) or both. As the amount of non-ferrous metal material input per unit time increases, the rotation speed of the circulation pump (20) is increased. In addition, by increasing the rotation speed of the circulation pump (20) as the difference between the upstream and downstream molten metal temperatures in the first heating chamber (12) increases, the thermal resistance from the first electric heater (30) and the second electric heater (40) to the non-ferrous metal material is reduced, thereby suppressing the internal temperature of the first electric heater (30) and the second electric heater (40) while maximizing the output of the first electric heater (30) and the second electric heater (40), and thus miniaturizing the entire furnace. It is characterized by the following:

[0009] Furthermore, the present invention is A method for melting non-ferrous metal materials using a circulating non-ferrous metal melting furnace (1), which is configured such that a first heating chamber (12) equipped with multiple first electric heaters (30) and a second heating chamber (13) equipped with multiple second electric heaters (40) are arranged side by side with an intermediate wall (15) in between to form a circulation path for molten metal, an inlet (11) for non-ferrous metal material is provided on one end of the intermediate wall (15) between the first heating chamber (12) and the second heating chamber (13), and the other end of the intermediate wall (15) is connected to a tapping chamber (14) from which molten metal can be removed, and the temperature is controlled in each of the first heating chamber (12) and the second heating chamber (13), and the molten metal is circulated via a circulation pump (20) provided in the first heating chamber (12) or the second heating chamber (13) or both, As the amount of non-ferrous metal material input per hour increases, the rotation speed of the circulation pump (20) is increased. Furthermore, as the difference between the upstream and downstream molten metal temperatures in the second heating chamber (13) increases, the rotation speed of the circulation pump (20) is increased. This reduces the thermal resistance from the first electric heater (30) and the second electric heater (40) to the non-ferrous metal material, suppressing the internal temperature of the first electric heater (30) and the second electric heater (40) while maximizing their output, thereby miniaturizing the entire furnace. It is characterized by the following:

[0013] Furthermore, the present invention is characterized in that the input ports (11, 21) for the non-ferrous metal material are provided on the upstream side of the first heating chamber (12) and the downstream side of the second heating chamber (13).

[0014] Furthermore, the present invention is characterized in that the non-ferrous metal material can be introduced into the high-velocity and low-velocity portions of the circulating molten metal according to the velocity distribution of the molten metal.

[0015] The symbols in parentheses above indicate the corresponding elements or items shown in the drawings and the embodiments for carrying out the invention described later. [Effects of the Invention]

[0016] According to the present invention, a circulating non-ferrous metal melting furnace is configured such that a first heating chamber equipped with multiple first electric heaters and a second heating chamber equipped with multiple second electric heaters are arranged side by side with an intermediate wall in between to form a circulation path for molten metal, an inlet for non-ferrous metal material is provided on one end of the intermediate wall, and the other end of the intermediate wall is connected to a tapping chamber from which molten metal can be removed, and the temperature is controlled in each of the first and second heating chambers, and the molten metal is circulated via a circulation pump. In this circulating non-ferrous metal melting furnace, the rotation speed of the circulation pump is increased as the amount of non-ferrous metal material input per unit time increases, so that the melting rate of the non-ferrous metal material increases.

[0017] Furthermore, according to the present invention, as the difference between the upstream and downstream molten metal temperatures in the first heating chamber increases, or as the difference between the upstream and downstream molten metal temperatures in the second heating chamber increases, the rotation speed of the circulation pump is increased, thereby suppressing the temperature inside each electric heater.

[0018] Furthermore, according to the present invention, since the inlet for non-ferrous metal material is provided on the upstream side of the first heating chamber and the downstream side of the second heating chamber, a large surface area of ​​the non-ferrous metal material in contact with the circulating molten metal can be secured, and the non-ferrous metal material can be melted efficiently.

[0019] Further, according to the present invention, by using a non-ferrous metal material, for example, a robot arm, etc., it can be introduced into a portion with a high flow rate or a low flow rate according to the velocity distribution of the circulating molten metal. Therefore, while increasing the circulation amount of the molten metal, the flow velocity of the molten metal on the surface of the introduced non-ferrous metal material can be reduced to suppress the melting rate. As a result, the difference between the upstream molten metal temperature and the downstream molten metal temperature in the first heating chamber and the difference between the upstream molten metal temperature and the downstream molten metal temperature in the second heating chamber can be made as small as possible.

[0020] As described above, according to the present invention, the thermal resistance from each electric heater to the non-ferrous metal material to be melted can be reduced. Therefore, the output of each electric heater can be maximized, and the circulating non-ferrous metal melting furnace can be downsized as a whole. As a result, a circulating non-ferrous metal melting furnace capable of exhibiting an extremely large melting capacity unprecedentedly can be installed in the area of a holding furnace having no melting power.

Brief Description of the Drawings

[0021] [Figure 1] It is a schematic plan view showing an embodiment of a circulating non-ferrous metal melting furnace according to the present invention. [Figure 2] It is a schematic plan view showing another embodiment of a circulating non-ferrous metal melting furnace according to the present invention. [Figure 3] It is a schematic plan view showing a conventional circulating non-ferrous metal melting furnace.

Mode for Carrying Out the Invention

[0022] Referring to the drawings, a non-ferrous metal melting method using a circulating non-ferrous metal melting furnace 1 according to an embodiment of the present invention will be described.

[0023] As shown in FIG. 1, the circulating non-ferrous metal melting furnace 1 according to the present embodiment circulates molten metal and immerses an electric heater, except for its upper end portion, in the molten metal, and uses its heat to melt and heat the non-ferrous metal material. It includes a furnace body 10, a circulation pump 20, a first electric heater 30, a second electric heater 40, thermometers T1 to T11, and a control unit 100 that controls the entire electrical system.

[0024] The furnace body 10 has a substantially rectangular planar shape with an outer shell formed by the furnace wall 10a, and includes an inlet 11 for non-ferrous metal materials, a first heating chamber 12, a second heating chamber 13, and a tapping chamber 14 from which molten metal can be taken out. Note that the planar shape of the furnace body 10 is not limited to a rectangular shape.

[0025] The inlet 11 is provided on the upstream side of the second heating chamber 13. The first heating chamber 12 is provided in communication with the inlet 11 and receives the non-ferrous metal materials introduced from the inlet 11. The second heating chamber 13 is arranged side by side with the first heating chamber 12 via an intermediate wall 15, and forms a circulation path in which molten metal circulates with the first heating chamber 12.

[0026] The tapping chamber 14 is provided at a position opposite to the inlet 11 via a diversion channel 18 provided so as to communicate with the upstream side of the second heating chamber 13. Between the first heating chamber 12 and the second heating chamber 13 and the diversion channel 18, they are partitioned by a partition wall 17 except for a gap channel 17a that communicates with the upstream side of the second heating chamber 13. A degassing device 70 that generates an inert gas to adsorb aluminum dross and make it float on the upper surface of the molten metal is attached to the diversion channel 18. Note that the aluminum dross is scraped out manually. This tapping chamber 14 is provided with a mechanism (not shown) for taking out the received molten metal to the outside. The inlet 11 is provided at one end side of the intermediate wall 15 between the first heating chamber 12 and the second heating chamber 13, and the other end side of the intermediate wall 15 between the first heating chamber 12 and the second heating chamber 13 is communicated with the tapping chamber 14.

[0027] Gap channels 16 (a first gap channel 16a and a second gap channel 16b) are formed between the furnace wall 10a and the partition wall 17 facing both ends of the intermediate wall 15, respectively. Therefore, the circulation path is formed in the order of the upstream side (inlet 11), the first gap channel 16a, the first heating chamber 12, the second gap channel 16b, and the second heating chamber 13.

[0028] The circulation pump 20 is installed downstream of the second heating chamber 13 and circulates the molten metal along the circulation path. The location and number of the circulation pumps 20 are not limited. Therefore, they can be installed in the first heating chamber 12, or they can be installed in both the first heating chamber 12 and the second heating chamber 13.

[0029] The first electric heater 30 is installed in the first heating chamber 12 and heats the molten metal to a predetermined first temperature. In this embodiment, a total of 11 first electric heaters 30 are installed, but this number is not limited. The second electric heater 40 is installed in the second heating chamber 13 and raises the molten metal, which has been heated to the first temperature in the first heating chamber 12, to a second temperature that exceeds the first temperature. In this embodiment, a total of six second electric heaters 40 are provided, but this number is not limited.

[0030] Thermometers T1 to T11 are thermocouple-type sensors, installed in the first heating chamber 12, the second heating chamber 13, and the molten metal outlet chamber 14, respectively, to measure the temperature of the molten metal. The number of these sensors is not limited.

[0031] The control unit 100, although not shown in the figure, includes a CPU, ROM, RAM, and other memory units, and controls the circulation pump 20, the first electric heater 30, and the second electric heater 40 based on temperature information from thermometers T1 to T11 and information on non-ferrous metal materials, respectively.

[0032] In this embodiment, the non-ferrous metal is an aluminum alloy. The first temperature is set to 650°C to 720°C, which is suitable for casting molten aluminum alloy products. The second temperature is set to 750°C, and the heat of the molten metal, which is about 100°C higher than the first temperature, is used to efficiently melt and heat the non-ferrous metal introduced from the inlet 11 in a short time. The first and second temperatures can be varied depending on the type of non-ferrous metal being melted and heated.

[0033] In this circulating non-ferrous metal melting furnace, the control unit 100 increases the rotation speed of the circulation pump 20 as the amount of non-ferrous metal material fed in per hour from the inlet 11 increases. According to this, the melting rate of non-ferrous metal materials can be increased, and the internal temperature of each electric heater 30, 40 can be suppressed.

[0034] Furthermore, the control unit 100 increases the rotational speed of the circulation pump 20 as the difference between the upstream molten metal temperature and the downstream molten metal temperature of the first heating chamber 12 increases, based on the temperatures detected by thermometers T1 and T3. This also increases the circulation rate of the molten metal, which helps to suppress the internal temperature of each electric heater 30, 40. Furthermore, the control unit 100 can increase the rotation speed of the circulation pump 20 not only on the first heating chamber 12 side, but also on the second heating chamber 13 side, as the difference between the upstream molten metal temperature and the downstream molten metal temperature of the second heating chamber 13 increases based on the temperatures detected by thermometers T5 and T7, thereby similarly suppressing the internal temperature of each electric heater 30, 40.

[0035] In this embodiment of the present invention, the inlet 11 for non-ferrous metal materials is provided on the downstream side of the second heating chamber 13 (first inlet 11), but as shown in Figure 1, the second inlet 21 can also be provided on the upstream side of the first heating chamber 12. By providing two input ports 11 and 21 for non-ferrous metal materials, a large surface area of ​​the non-ferrous metal material in contact with the circulating molten metal can be secured, allowing for efficient melting of the non-ferrous metal material.

[0036] Furthermore, by using the non-ferrous metal material inlet ports 11 and 21, or in combination with them, as shown in Figure 2, non-ferrous metal materials can be freely introduced into areas with high or low flow velocity according to the velocity distribution of the circulating molten metal, for example, by using robot arms R1 and R2. According to this, the difference between the upstream and downstream molten metal temperatures in the first heating chamber 12, and the difference between the upstream and downstream molten metal temperatures in the second heating chamber 13, can be minimized as much as possible.

[0037] Furthermore, in this embodiment of the present invention, a gap passage 17a is provided on the upstream side of the second heating chamber 13, and the molten metal is flowed to the tapping chamber 14 via the guide channel 18. However, the invention is not limited to this, and as shown in Figure 2, a gap passage 17a can also be provided on the downstream side of the first heating chamber 12, and the molten metal is flowed to the tapping chamber 14 via the guide channel 18. Alternatively, the guide channel 18, which is equipped with the degassing device 70, can be omitted, and the gap passage 17a can be directly connected to the tapping chamber 14.

[0038] In the above embodiments of the present invention, aluminum alloys are used for melting and heating, but other non-ferrous alloys can also be used. Furthermore, the first and second temperatures can be appropriately changed depending on the non-ferrous metal being targeted. [Explanation of symbols]

[0039] 1 Circulating non-ferrous metal melting furnace 10 Furnace body 10a Furnace wall 11 Inlet (first inlet) 12. First Temperature-Boosting Chamber 13. Second Temperature-Boosting Chamber 14 Hot spring room 15 Intermediate wall 16 Interstitial path 16a First gap path 16b Second gap path 17 Bulkhead 17a Gap passage 18 Channel 20 Circulation pump 21 Second input port 30 Daiichi Electric Heater 40 Second Electric Heater 50 Circulating non-ferrous metal melting furnace 51 Melting chamber 52 Warming room 53 Debris Removal Room 54 Sedation Room 55 Hot spring room 56 Electric heater 70 Degassing equipment 100 Control Unit R1, R2 Robot Arms T1~T11 Thermometer

Claims

1. A method for melting non-ferrous metal materials using a circulating non-ferrous metal melting furnace, comprising: a first heating chamber equipped with multiple first electric heaters and a second heating chamber equipped with multiple second electric heaters arranged side by side with an intermediate wall in between to form a circulation path for molten metal; an inlet for non-ferrous metal materials provided at one end of the intermediate wall between the first and second heating chambers, and the other end of the intermediate wall connected to a tapping chamber from which molten metal can be removed; temperature control performed in each of the first and second heating chambers, and molten metal circulated via a circulation pump provided in the first heating chamber, the second heating chamber, or both; A method for melting non-ferrous metals, characterized by increasing the rotation speed of the circulation pump as the amount of non-ferrous metal material input per unit time increases, and increasing the rotation speed of the circulation pump as the difference between the molten metal temperature on the upstream side and the molten metal temperature on the downstream side of the first heating chamber increases, thereby reducing the thermal resistance from the first electric heater and the second electric heater to the non-ferrous metal material, suppressing the internal temperature of the first electric heater and the second electric heater, maximizing the output of the first electric heater and the second electric heater, and miniaturizing the entire furnace.

2. A method for melting a non-ferrous metal material using a circulating non-ferrous metal melting furnace, wherein a first heating chamber provided with a plurality of first electric heaters and a second heating chamber provided with a plurality of second electric heaters are arranged side by side with an intermediate wall in between to form a circulation path for molten metal, an inlet for non-ferrous metal material is provided on one end of the intermediate wall between the first heating chamber and the second heating chamber, and the other end of the intermediate wall is connected to a tapping chamber from which molten metal can be removed, the temperature is controlled in each of the first heating chamber and the second heating chamber, and the molten metal is circulated via a circulation pump provided in the first heating chamber or the second heating chamber or both, A method for melting non-ferrous metals, characterized by increasing the rotation speed of the circulation pump as the amount of non-ferrous metal material input per unit time increases, and increasing the rotation speed of the circulation pump as the difference between the molten metal temperature on the upstream side and the molten metal temperature on the downstream side of the second heating chamber increases, thereby reducing the thermal resistance from the first electric heater and the second electric heater to the non-ferrous metal material, suppressing the internal temperature of the first electric heater and the second electric heater, maximizing the output of the first electric heater and the second electric heater, and miniaturizing the entire furnace.

3. The method for dissolving non-ferrous metals according to claim 1 or 2, characterized in that the input ports for the non-ferrous metal material are provided on the upstream side of the first heating chamber and on the downstream side of the second heating chamber.

4. The method for melting non-ferrous metals according to claim 1 or 2, characterized in that the non-ferrous metal material can be introduced into the fast-flowing or slow-flowing portions of the circulating molten metal according to the velocity distribution of the molten metal.

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