Aluminum melting system

Abstract

To provide an aluminum melting system which integrates a melting furnace of cutting chips and a melting furnace of an ingot, shares a commonly used member, and can achieve space saving and energy consumption reduction.SOLUTION: An aluminum melting system comprises a cutting chip melting furnace 11 for melting a cutting chip raw material, an ingot melting furnace 12 for melting an ingot raw material, a molten metal holding chamber 13 which is communicated with the cutting chip melting furnace through a first communication part 21, is communicated with the ingot melting furnace through a second communication part 22, and heats and holds aluminum molten metal, a degassing chamber 14 which is communicated with the molten metal holding chamber 13 through a third communication part 23 and performs degassing treatment by blowing inert gas into the aluminum molten metal, and a filtration chamber 15 which is communicated with the degassing chamber 14 through a fifth communication part 25 and filters and cleans the aluminum molten metal subjected to the degassing treatment, and is configured to supply aluminum cutting chips and / or aluminum ingot on the basis of molten metal level information acquired by a molten metal level sensor provided on the filtration chamber 15.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an aluminum melting system in which a cutting chip melting furnace and an ingot melting furnace are connected to both sides of a molten metal holding chamber and integrated together. [Background technology]

[0002] This is a technology to recycle cutting scraps and turnings of non-ferrous metal materials such as aluminum and aluminum alloys by melting them in a melting furnace and making them into ingots. For example, Patent Document 1 (JP Patent Publication No. 6-207230A) states: The publication describes an aluminum cutting chip melting apparatus that uses a vortex chamber as a melting furnace for aluminum cutting chips, and mixes the aluminum cutting chips into circulating molten metal to melt them. In addition, Patent Document 2 (JP 2016-107333 A) states: A non-ferrous metal melting furnace is described which is equipped with an induction heating coil that directly heats molten aluminum and aluminum ingots in a melting vessel at or above the effective temperature of the induction magnetic field using an induction magnetic field. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-207230 [Patent Document 2] JP 2016-107333 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional aluminum melting systems, Since cutting chips of non-ferrous metal materials such as aluminum and aluminum alloys are easily oxidized, we use an aluminum cutting chip melting device that mixes them into circulating molten metal and melts them. In addition, two types of melting equipment were introduced: a non-ferrous metal melting furnace that uses an induction magnetic field to directly heat ingots and return materials. This resulted in issues such as the cost of installing melting equipment and energy waste. Therefore, the present invention provides the following when melting cutting chips and ingots: The two types of melting furnaces are integrated, and the common parts are standardized. The objective is to provide an aluminum melting system that leads to space saving and energy consumption reduction in aluminum casting factories. [Means for solving the problem]

[0005] The aluminum melting system of the present invention has the following features. (1) a cutting chip melting furnace for melting aluminum cutting chip raw material; an ingot melting furnace for melting aluminum ingot raw materials; The cutting chip melting furnace is connected to the cutting chip melting furnace through a first communication part, The ingot melting furnace is connected to the second connecting portion. A molten metal holding chamber for heating and holding the molten aluminum; communicates with the molten metal holding chamber via a third communication portion; A degassing chamber in which inert gas is blown into the molten aluminum to degas it, The degassing chamber is connected to the degassing chamber via a fifth communication part, A filtering chamber for filtering and purifying the degassed molten aluminum; Based on molten metal level information acquired by a molten metal level sensor provided in the filtering chamber, The present invention is characterized in that aluminum cutting chips and / or aluminum ingots are supplied. (2) The ingot melting furnace has a bottom that is gradually inclined toward the molten metal holding chamber that communicates with the ingot melting furnace through the second communication portion. (3) The bottom of the degassing chamber is characterized in that it is gradually inclined toward the molten metal holding chamber which communicates with it. (4) The degassing chamber is a first degassing chamber and a second degassing chamber, The arrangement of the rotor shafts in each degassing chamber is as follows: In plan view, The distance from the molten metal holding chamber side to the side wall on the opposite side is characterized by X>Y. (5) The present invention is characterized in that a step is provided so that the height of the hearth of the degassing chamber is higher than the height of the hearth of the molten metal holding chamber. Effect of the Invention

[0006] The aluminum melting system of the present invention is constructed by connecting two aluminum melting furnaces, a cutting chip melting furnace and an ingot melting furnace, with a molten metal holding chamber in between, and by integrating the molten metal holding chamber, degassing chamber, and filtration chamber through a communication section. This allows the aluminum melting equipment to be made smaller, saving space and reducing energy consumption, making it applicable to small-scale production. In addition, the molten aluminum can be stored integrally through the communicating portion, and processing of the molten aluminum, such as degassing and purification, can be carried out efficiently. In addition, depending on the amount of cutting waste and ingots generated and their availability, This is a system that allows the consumption of raw materials with large stocks to be prioritized. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view showing an entire embodiment of an aluminum melting system of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line BB in FIG. [Figure 4] FIG. 4 is a plan view showing the state of eccentric rotating shafts 14c and 14d when two degassing chambers 14a and 14b are installed. [Diagram 5] FIG. 5 is a cross-sectional view taken along line CC of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The aluminum melting system of this embodiment includes a cutting chip melting furnace 11 for melting aluminum cutting chip raw material, an ingot melting furnace 12 for melting aluminum ingot raw materials; The cutting chip melting furnace 11 is connected to the cutting chip melting furnace 11 via a first communication portion 21, The ingot melting furnace 12 is connected to the second connecting portion 22. A molten metal holding chamber 13 for heating and holding the molten aluminum; The molten metal holding chamber 13 communicates with the molten metal holding chamber 13 via a third communication portion 23, a degassing chamber 14 for blowing inert gas into the molten aluminum to perform degassing treatment; The degassing chamber 14 communicates with the fifth communication portion 25, a filtering chamber 15 for filtering and purifying the degassed molten aluminum; The present invention is characterized in that aluminum cutting chips and / or aluminum ingots are supplied based on molten metal level information acquired by a molten metal level sensor 16 provided in the filtering chamber 15.

[0009] Hereinafter, a detailed explanation will be given with reference to FIGS. 1 to 5. The aluminum melting system of this embodiment is provided with a melting furnace for melting aluminum ingots and a melting furnace for melting aluminum cutting chips separately, This aluminum melting system is comprised of a molten metal holding chamber, a degassing chamber, a filtration chamber, etc., all connected together via communication parts that serve as a flow path for the molten aluminum. The aluminum melting system of the embodiment is constructed as an integrated unit via communicating parts, so that the molten aluminum can flow through these communicating parts and be made uniform.

[0010] <Aluminum cutting chip melting furnace> Each component will be described in detail below with reference to FIGS. 1 to 5. The aluminum cutting chips melting furnace 11 (hereinafter referred to as cutting chips melting furnace) is a melting furnace that uses aluminum cutting chips as a melting raw material. Aluminum cutting chips are supplied from a raw material hopper 11b via a supply feeder 11a. It is preferable to use, as the aluminum cutting chips melting furnace 11, a whirlpool type melting furnace in which the introduced cutting chips are entrained in the molten aluminum. Fine raw materials such as aluminum cutting chips oxidize when heated with a burner, making them difficult to melt, so a melting furnace in which the raw materials are dropped into a vortex of molten aluminum is preferably used.

[0011] <Aluminum ingot melting furnace> The aluminum ingot melting furnace 12 (hereinafter referred to as an ingot melting furnace) is a melting furnace that uses aluminum ingots (aluminum chunks or aluminum wheel scraps, hereinafter referred to as aluminum ingots) as a melting raw material. The aluminum ingot is melted using a gas burner 18 or the like as a heat source. In the ingot melting furnace 12, the aluminum ingot begins to melt successively from the portion irradiated with the gas burner 18 having an exhaust heat recovery function, and falls to the furnace bottom 12f as molten aluminum. As shown in FIG. 2, the ingot melting furnace 12 has a furnace bottom 12f that is inclined so as to gradually lower toward the molten metal holding chamber 13. Therefore, the molten aluminum that falls to the furnace bottom 12f flows slowly into the molten metal holding chamber 13 through the second communication part 22, following the inclination formed in the furnace bottom 12f.

[0012] <Molten metal holding chamber> The molten metal holding chamber 13 is a refractory structure formed in a substantially box-like shape that heats and holds the molten aluminum stored therein by a heating device, and is equipped with heating devices such as gas burners 18 on the ceiling and side walls. The molten metal holding chamber 13 communicates with the cutting chip melting furnace 11 via a first communication portion 21, It is in communication with the ingot melting furnace 12 via a second communication part 22, It has the function of heating and maintaining the molten aluminum flowing from two melting furnaces (cutting chip melting furnace and ingot melting furnace) using a heating device such as a gas burner 18.

[0013] The gas burner 18 in the molten metal holding chamber 13 is a combustion device that mixes gas fuel with oxygen in the air and burns it. The ignition of the gas burner 18 and other operations can be adjusted based on a signal received from a molten metal temperature sensor 16b provided in the molten metal holding chamber 13.

[0014] <Degassing chamber> The degassing chamber 14 is a structure lined with a fire-resistant material for blowing an inert gas into the molten aluminum to remove gas (hydrogen) contained in the molten aluminum. When aluminum is melted, it reacts with moisture in the air and absorbs hydrogen, which turns into bubbles when it solidifies and becomes tiny casting defects (pinholes). Furthermore, the raw materials for molten aluminum contain elements such as Sr and Sb that combine with oxygen to become impurities, which can reduce the cleanliness of the molten aluminum. In addition, aluminum cutting chips generated during machining have a large surface area and therefore have a large amount of oxide film (oxide). For this reason, a degassing chamber 14 is provided to remove hydrogen gas and impurities from the molten aluminum.

[0015] In addition, since the degassing chamber is connected to the molten metal holding chamber 13 via the third communication portion 23, when the molten aluminum in the degassing chamber 14 falls below a predetermined level, the molten aluminum flows in from the molten metal holding chamber 13, In the degassing chamber 14, the rotating shafts 14c and 14d of the rotor provided in the degassing chamber 14 are equipped with pipes for blowing in an inert gas such as nitrogen or argon gas, and the rotor is rotated while blowing in the inert gas to stir the molten aluminum and degasify the hydrogen and impurities contained in the molten aluminum.

[0016] In this embodiment, the degassing chamber 14 is configured as two chambers. As shown in FIG. 4, the degassing chamber 14 is a first degassing chamber 14a and a second degassing chamber 14b, and the arrangement of the rotor shafts 14c and 14d provided in each degassing chamber is as follows: In plan view, the distances from the molten metal holding chamber 13 side and the side wall 14e on the opposite side were set to X>Y, and the eccentric position was determined. As a result, the molten aluminum flowing from the first degassing chamber 14a to the second degassing chamber 14b is strongly stirred and flowed, thereby increasing the effect of removing impurities.

[0017] Since the specific gravity of impurities and oxides is greater than that of the molten aluminum, they tend to accumulate on the furnace bottom 14 f of the degassing chamber 14 . For this reason, the hearth 14f of the degassing chamber 14 is formed so as to be inclined lower toward the communicating molten metal holding chamber 13, so that impurities in the degassing chamber 14 are dropped into the melting holding chamber 14 at the lower hearth and damage to the rotor in the degassing chamber 14 is prevented. This inclination angle is not limited, but taking into consideration the flow of molten metal, it is preferably about 1 to 5 degrees.

[0018] In this embodiment, as shown in FIG. 5, a step is formed so that the height of the hearth 14f of the degassing chamber 14 is higher than the height of the hearth 13f of the molten metal holding chamber 13. This prevents impurities present in the hearth 13f of the molten metal holding chamber 13 from flowing into the degassing chamber 14, and prevents the impurities from interfering with the rotors and damaging the rotating shafts 14c and 14d.

[0019] <Filtration chamber> The filtration chamber 15 is a substantially box-shaped refractory structure for removing impurities from the molten aluminum degassed in the degassing chamber 14 . As shown in FIG. 5, the filtration chamber 15 has a function of filtering the molten aluminum that has flowed in from the degassing chamber 14 via the fifth communication portion 25 through a ceramic filter provided in the filtration chamber 15. The filtered molten aluminum is tapped into an ingot case or the like from a tapping section provided at the top.

[0020] <Molten metal level sensor 16> In the aluminum melting system of the present embodiment, a molten metal level sensor 16 is provided in the filtering chamber 15 to detect the level of the stored amount of molten aluminum that has flowed into the filtering chamber 15 via the fifth communication portion 25. A molten aluminum level sensor 16 provided in the filtration chamber 15 estimates the level of the molten aluminum in each chamber integrated via each communication part, and monitors information on the molten aluminum in the entire aluminum melting system. The molten metal level sensor 16 may be an immersion type sensor that detects electrical continuity by contacting the molten aluminum in the filtering chamber 15, or a laser sensor that obtains the molten metal level by irradiating the surface of the molten aluminum with a laser.

[0021] <Molten metal temperature sensor> Further, the filtering chamber 15 is provided with a molten aluminum temperature sensor for measuring the temperature of the molten aluminum as a sensor for monitoring information on the molten aluminum. By using the molten metal level sensor 16 and the molten metal temperature sensor 17 alone or in combination, it is possible to monitor the molten aluminum information in the aluminum melting system more precisely.

[0022] <Raw material supply> In the present invention, the supply of melting raw materials to the aluminum cutting chip melting furnace and the ingot melting furnace is controlled based on molten metal information obtained by the molten metal level sensor 16 and the molten metal temperature sensor 17 provided in the filtering chamber 15. That is, when it comes to supplying raw materials to the aluminum cutting scraps melting furnace and the ingot melting furnace, priority is given to the consumption of the aluminum cutting scraps because the aluminum cutting scraps are easily oxidized and bulky. At the same time, the supply amount is controlled based on the consumption of aluminum cutting scraps and the melting of ingots. The supply amount of the aluminum cutting chips and / or aluminum ingots is controlled based on molten metal information obtained by a molten metal level sensor 16 and a molten metal temperature sensor 17 provided in the filtering chamber 15. For example, the supply ratio (mass ratio) of aluminum cutting chips to aluminum ingot is preferably about 4 parts aluminum ingot to 1 part aluminum cutting chips in terms of melting efficiency, but is not particularly limited to this ratio. Even if the mass ratio of the aluminum cutting chips 1 is "1", the aluminum cutting chips are bulky and the volume of the material to be supplied to the melting furnace is large. Therefore, for example, the supply of the raw material is controlled as follows. (1) Once the drop in the molten metal level is confirmed, aluminum cutting chips are fed preferentially to the cutting chip melting furnace 11. (2) Monitor the consumption of aluminum cutting scraps. (3) Once the aluminum cutting scraps have been consumed, the ingots are charged into an aluminum ingot melting furnace 12. That is, in the aluminum melting system of this embodiment in which the ingot melting furnace, the cutting chip melting furnace, the molten metal holding chamber, the degassing chamber, and the filtration chamber are integrated, When the molten metal information in the filtering chamber 15 increases or decreases relative to a reference value, the consumption of the aluminum cutting chips is prioritized, and when the remaining amount of the aluminum cutting chips reaches or falls below the reference value, the ingots are charged into the aluminum ingot melting furnace 12. In this way, by controlling the consumption of aluminum cutting chips and ingots so that they are melted using the respective melting furnaces, the amount of molten aluminum discharged from the melting furnaces can be stabilized. [Industrial Applicability]

[0023] As described above, the aluminum melting system of the present invention connects two aluminum melting furnaces, a cutting chip melting furnace and an ingot melting furnace, with a molten metal holding chamber in between, and integrates the molten metal holding chamber, degassing chamber, and filtration chamber via a communicating section. This allows the aluminum melting equipment to be miniaturized, saving space and reducing energy consumption, making it applicable to small-scale production and highly applicable industrially. [Explanation of symbols]

[0024] 11 Cutting waste melting furnace, 11a supply feeder, 11b raw material hopper, 12 ingot melting furnace, 12f Bottom of ingot melting furnace 12 13 Molten metal holding chamber, 13f Bottom of molten metal holding chamber 13 14 Degassing chamber, 14a first degassing chamber, 14b second degassing chamber, 14c, 14d Rotation axis 14e Side wall opposite the molten metal holding chamber 14f: bottom of the degassing chamber 14; 15 filtration chamber, 16 Molten metal level sensor, 17 Molten metal temperature sensor, 18 Gas burner 21 1st communication part, 22 2nd communication part, 23 Third communication part, 24 4th communication part, 25 5th communication part,

Claims

1. a cutting chip melting furnace for melting aluminum cutting chip raw material; an ingot melting furnace for melting aluminum ingot raw materials; The cutting chip melting furnace is connected to the cutting chip melting furnace through a first communication portion, The ingot melting furnace is connected to the second connecting portion. A molten metal holding chamber for heating and holding the molten aluminum; the molten metal holding chamber is connected to the third connecting portion; A degassing chamber in which inert gas is blown into the molten aluminum to degas it, The degassing chamber is connected to the fifth communication portion, A filtering chamber for filtering and purifying the degassed molten aluminum; Based on molten metal level information acquired by a molten metal level sensor provided in the filtering chamber, 1. An aluminum melting system comprising: a first aluminum cutting chip and / or an aluminum ingot;

2. The bottom of the ingot melting furnace is 2. The aluminum melting system according to claim 1, wherein the second communicating portion is inclined so as to gradually decrease in a direction toward the molten metal holding chamber which communicates with the second communicating portion.

3. The bottom of the degassing chamber is 2. The aluminum melting system according to claim 1, wherein the molten metal holding chamber is inclined so as to gradually decrease in a direction toward the molten metal holding chamber that communicates with the molten metal holding chamber.

4. The degassing chamber includes a first degassing chamber and a second degassing chamber, The arrangement of the rotor shafts in each degassing chamber is as follows: In plan view, 2. The aluminum melting system according to claim 1, wherein the distances from the molten metal holding chamber side and the opposite side wall satisfy X>Y.

5. The height of the bottom of the degassing chamber is The height of the furnace bottom of the molten metal holding chamber is set to be higher than that of the furnace bottom of the molten metal holding chamber.

2. The aluminum melting system according to claim 1, further comprising a step.

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