JP3947452B2 - Non-ferrous metal scrap melting furnace - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to non-ferrous metals such as aluminum and aluminum alloys, chips generated during machining of cast products, sculpting chips generated during the peeling process of slabs and billets, crushed waste from used beverage cans, sashes The present invention relates to a melting furnace for melting crushed scraps and other scrap pieces (hereinafter simply referred to as scraps).
[0002]
[Prior art]
A large amount of waste is generated in the process of processing non-ferrous metals such as aluminum and aluminum alloys and recycling scrap, but these wastes are melted in a melting furnace to be reused. Since these scraps are thin and have a low bulk specific gravity, when dropped on the surface of the molten metal, they float on the molten metal due to the surface tension of the molten metal and the oxide film, and during this time they are exposed to a high-temperature oxidizing atmosphere. It becomes a ugly oxide. For this reason, it is considered as an effective essential condition for melting these scraps to quickly sink the waste below the surface of the molten metal, and a method and an apparatus for generating vortex or turbulent flow to entrain the molten metal in the molten metal. Has been traditionally devised. Driving sources for generating vortex and turbulent flow in the molten metal are roughly classified into those using a molten metal circulation pump using an electric motor or an air motor and those using a so-called electromagnetic force that moves a magnetic field.
Such non-ferrous metal scrap melting furnaces are disclosed in Patent Document 1 and Patent Document 2 presented below.
[0003]
[Patent Document 1]
Japanese Patent No. 2554510 [Patent Document 2]
US Pat. No. 6,217,823 Specification
As shown in FIG. 6, the melting furnace disclosed in Patent Document 1 includes a heating chamber 2, a vortex chamber 10, and a culvert portion 11, and a pump 3 is provided between the culvert portion 11 and the heating chamber 2. And while operating this pump 3 and circulating the molten metal M, scraps of non-ferrous metal are put into the vortex chamber 10. The thrown-in waste is melted in the vortex chamber 10 and the culvert portion 11, and becomes a molten metal M that reaches the temperature raising chamber 2. The side wall of the vortex chamber 10 constitutes a vertical surface 10a.
[0005]
Further, as disclosed in Patent Document 2, as shown in FIG. 7, the lower end portion of the vortex chamber 20 is an inclined wall 20a having an inverted conical cross section, and an upward flow channel 21 communicating with the lower side of the inclined wall 20a. Then, the molten metal M is pumped in, and the molten metal M is swirled upward along the inclined wall 20a, and then flows out of the discharge port 22 by its own weight.
[0006]
[Problems to be solved by the invention]
It is an essential condition to quickly submerge the debris below the surface of the melt, but it takes a certain amount of time for the debris to completely dissolve, so it is further necessary to continue to retain debris that tends to float below the surface of the melt. .
Since the melting furnace disclosed in Patent Document 1 is provided with a discharge port 10b having a narrow diameter at the bottom of the vortex chamber 10, the molten metal is guided from the temperature raising chamber 2 to the vortex chamber 10 when the pump 3 is operated. During the passage of the molten metal given the flow velocity by passing through the discharge port 10b and passing through the culvert portion 11 and the pump 3 while retaining the waste, the laminar flow vortex is formed and the waste is rapidly wound. The waste is completely dissolved and returned to the heating chamber 2 again. It is an excellent melting furnace with little oxidation loss because the entrained scrap does not immediately float on the surface of the molten metal.
[0007]
However, in the melting furnace shown in FIG. 6, foreign matter such as iron pieces mixed in the scrap dropped in the vortex chamber 10 reaches the pump 3 or reaches the pump 3 before the thick scrap is completely melted. There was a problem that 3 was damaged.
In addition, there is a problem that dross accumulates in the underdrain portion 11 and must be periodically cleaned.
[0008]
In addition, the melting furnace as shown in FIG. 7 introduces the molten metal M into the vortex chamber 20 while flowing the molten metal in an upward spiral along the inclined wall 20a, and then flows out from the discharge port 22 due to its own weight. I am letting. For this reason, the molten metal M cannot form a strong vortex in the vortex chamber 20, and the molten metal that simply passes through the discharge port 22 by its own weight is given a flow velocity sufficient to keep the debris below the molten metal surface. In other words, there is a problem that the waste tends to float on the molten metal surface on the downstream side of the discharge port 22. As a result, the surfacing waste is exposed to a high-temperature oxidizing atmosphere, resulting in oxidation loss.
[0009]
Therefore, the object of the present invention is to completely dissolve the scrap before reaching the pump, to prevent the pump from being damaged, and to have an excellent nonferrous metal scrap melting furnace with little oxidation loss. Is to provide.
Another object of the present invention is to provide an excellent nonferrous metal scrap melting furnace with little oxidation loss by completely melting scrap even when an electromagnetic induction device is used instead of a pump.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a nonferrous metal scrap melting furnace according to claim 1 of the present invention includes a heating chamber (2) provided with a burner (6) for heating the molten metal (M), a nonferrous metal In a melting furnace provided with a vortex chamber (1) into which scraps are charged and a pump (3) for circulating molten metal (M), the vortex chamber (1) is located immediately downstream of the pump (3), and The discharge port (1c) provided on the upstream side of the temperature raising chamber (2) and at the lower part of the vortex chamber (1) is positioned at a position lower than the hot water surface (S) of the temperature raising chamber (2). M) and the lower part of the vortex chamber (1) is formed into a substantially inverted conical shape by a tapered wall (1a), and further from the discharge port of the pump (3) to the vortex chamber (1). in the flow path (5) the bottom of the vortex chamber (1) elevated surface inclined toward the side and (5a), the discharge force of the pump (3), The molten metal (M) is swirled from the discharge port (1c) of the pump (3) through the rising surface (5a) to a swirl chamber (1) from a level higher than the hot water surface (S) of the heating chamber (2). The vortex chamber (1) is supplied to a position lower than the hot water surface (S) of the temperature raising chamber (2).
[0012]
A non-ferrous metal scrap melting furnace according to claim 2 is the invention according to claim 1 , wherein the molten metal (M) is passed through the spiral guide path (4) to the tapered wall (1a). It supplies to an upper end part, It is characterized by the above-mentioned.
[0014]
Symbols in parentheses indicate corresponding elements or corresponding matters described in the drawings and embodiments of the invention described later.
[0015]
According to the nonferrous metal scrap melting furnace of claim 1 of the present invention, the vortex is swirled into the vortex chamber so that the molten metal flows down from a level higher than the hot water surface of the heating chamber from a high place to a low place by the discharge force of the pump. Therefore, it is possible to form a strong laminar vortex, whereby the waste can be quickly and effectively wound into the molten metal.
Further, the molten metal entrained with debris is given a flow velocity when passing through the discharge port at the lower part of the vortex chamber by the discharge force of the pump, and the molten metal is discharged downstream of the vortex chamber while retaining the entrained debris. .
[0016]
Furthermore, since the vortex chamber is provided immediately downstream of the pump and upstream of the heating chamber, the waste dropped in the vortex chamber is completely dissolved in the vortex chamber and the heating chamber located downstream of the vortex chamber. be able to.
Therefore, non-dissolved waste does not reach the pump, and even if foreign matter such as iron pieces is mixed into the waste, they settle in the heating chamber downstream of the pump, which causes damage to the pump. Can be prevented in advance.
[0017]
Furthermore, since the waste thrown into the vortex chamber can be completely dissolved by the time it reaches the pump, a conventional culvert portion is not required. Therefore, the convenience that the downsizing of the melting furnace and the periodic cleaning of the culvert can be omitted is provided.
[0021]
Further, according to the invention described in claim 1 , since the lower part of the vortex chamber is a tapered wall having a substantially inverted conical section, unlike the melting furnace shown in FIG. 6 in which the tapered wall is not formed in the vortex chamber. A powerful spiral flow can be easily formed.
The tapered wall also gives a flow rate to the molten metal when combined with the discharge force of the pump or the electromagnetic force of the electromagnetic induction device when the swirl flow of the formed molten metal is discharged from the vortex chamber.
Thereby, the thrown-down waste can be dissolved more quickly, the oxidation loss of the waste can be reduced, and when the pump is used, damage to the pump can be prevented more reliably.
[0022]
Furthermore, according to the second aspect of the present invention, since the molten metal is supplied to the upper end portion of the tapered wall via the guide path, a strong spiral flow can be smoothly formed by the tapered wall. Therefore, scraps can be quickly caught in the molten metal, and oxidation loss can be further reduced.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 thru | or FIG. 4, the nonferrous metal waste melting furnace which concerns on embodiment of this invention is demonstrated. FIG. 1 is a schematic perspective view showing a non-ferrous metal scrap melting furnace according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing a main part of the non-ferrous metal scrap melting furnace. 3 is a plan view showing the vortex chamber 1 of the melting furnace in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line AA in FIG. In addition, the same code | symbol was attached | subjected to the same part as what was shown in the prior art example.
[0024]
A nonferrous metal scrap melting furnace according to an embodiment of the present invention melts scraps of aluminum or aluminum alloy, and includes a temperature raising chamber 2, a vortex chamber 1, and a pump 3.
The heating chamber 2 is provided with a plurality of burners 6, and the molten metal M is heated by the burners 6. Waste is introduced into the vortex chamber 1. The pump 3 circulates the molten metal M in the melting furnace.
[0025]
In such a configuration, the vortex chamber 1 is provided in the immediate vicinity of the downstream side of the pump 3 and upstream of the temperature raising chamber 2, and the molten metal M is discharged from a level higher than the level S of the temperature rising chamber 2 by the discharge force of the pump 3. The vortex chamber 1 is supplied in a spiral shape. At the same time, the bottom surface of the flow path 5 from the pump 3 to the vortex chamber 1 is the rising surface 5 a, and the level S of the molten metal M flowing into the vortex chamber 1 is more easily higher than the level S of the heating chamber 2. Is set to reach.
[0026]
In addition, the vortex chamber 1 has a cylindrical shape with an upper portion constituted by a vertical wall 1 b, and a lower portion thereof has a substantially inverted conical shape by a tapered wall 1 a, and the molten metal M is passed through a spiral guide path 4. The taper is supplied to the upper end of the taper wall 1a.
[0027]
In this non-ferrous metal scrap melting furnace, when the pump 3 is operated, the molten metal M is supplied to the upper end of the tapered wall 1a of the vortex chamber 1 from a level higher than the hot water surface S of the heating chamber 2. Since the supplied molten metal M flows down toward the discharge port 1c along the tapered wall 1a, a large spiral flow is formed. Accordingly, the waste dropped into the vortex chamber 1 is quickly and effectively dissolved by the vortex flow.
[0028]
The molten metal M discharged from the discharge port 1c of the vortex chamber 1 while being given a flow velocity by the discharge force of the pump 3 reaches the heating chamber 2 while retaining the waste in the molten metal M, and the burner 6 installed in the heating chamber 2 Even if there is debris that has not been completely dissolved during the stay, it is completely dissolved in the heating chamber 2.
[0029]
The molten metal M heated in the temperature raising chamber 2 is supplied again to the vortex chamber 1 by the suction force of the pump 3. At this time, since the waste previously thrown into the vortex chamber 1 is completely dissolved, it does not reach the pump 3 in an undissolved state.
In addition, foreign matters such as iron pieces mixed in scrap pass through the vortex chamber 1, are carried to the temperature raising chamber 2 at the flow rate of the molten metal M, and settle down, and do not reach the pump 3. These settled foreign matters can be removed from the temperature raising chamber 2 during the purification or removal work of the molten metal M performed as appropriate.
Therefore, the pump 3 is not damaged by the waste dropped into the vortex chamber 1.
[0030]
Moreover, in this melting furnace, since the waste thrown into the vortex chamber 1 can be completely dissolved before reaching the pump 3, a culvert portion is not required. Therefore, it is possible to reduce the size of the melting furnace and eliminate regular cleaning of the culvert.
[0031]
As shown in FIG. 5, an electromagnetic induction device 30 is provided instead of the pump 3, and the molten metal M is vortexed from a level higher than the hot water surface S of the heating chamber 2 by an electromagnetic force that moves the magnetic field of the electromagnetic induction device 30. The molten metal M can also be circulated so as to be spirally supplied to the chamber 1.
In this case, the vortex chamber 1 is provided immediately downstream of the electromagnetic induction device 30 and upstream of the temperature raising chamber 2.
[0032]
According to this, by the electromagnetic force that moves the magnetic field of the electromagnetic induction device 30, the molten metal M spirals into the vortex chamber 1 so as to flow down from a level higher than the hot water surface S of the heating chamber 2 from a high place to a low place. As a result of the supply, a strong laminar vortex can be formed, whereby the waste can be quickly and effectively entrained in the melt.
Further, the molten metal M in which the waste is entrained is given a flow velocity when passing through the discharge port 1c in the lower part of the vortex chamber 1 by the electromagnetic force that moves the magnetic field of the electromagnetic induction device 30, and the molten metal M retains the entrained waste. As it is, it is discharged downstream of the vortex chamber 1.
[0033]
Furthermore, since the vortex chamber 1 is provided in the immediate vicinity of the downstream side of the electromagnetic induction device 30 and on the upstream side of the temperature raising chamber 2, the waste dropped in the vortex chamber 1 is located in the vortex chamber 1 and the downstream side thereof. It can be completely dissolved in the temperature raising chamber 2.
[0034]
Furthermore, since the waste thrown into the vortex chamber 1 can be completely dissolved before reaching the electromagnetic induction device 30, a culvert portion is not required. Therefore, the convenience that the downsizing of the melting furnace and the periodic cleaning of the culvert can be omitted is provided.
[0035]
【The invention's effect】
As described above, according to the non-ferrous metal scrap melting furnace according to claim 1 of the present invention, the vortex chamber is provided in the immediate vicinity of the downstream side of the pump and the upstream side of the temperature raising chamber. The chips can be completely dissolved in the vortex chamber and the temperature raising chamber located downstream thereof. Moreover, foreign matters such as iron pieces mixed in the scraps pass through the vortex chamber, and are carried to the heating chamber at the flow rate of the molten metal and settle. The settled foreign matter can be easily removed during the purification or demolition work of the molten metal appropriately performed. Therefore, undissolved scraps and foreign matter such as iron pieces do not reach the pump, thereby preventing damage to the pump.
[0036]
In addition, the pump's discharge force causes the molten metal to be spirally supplied to the vortex chamber from a level higher than the hot water surface of the temperature raising chamber to flow from a high place to a low place, so that a strong swirl flow can be formed. This also makes it possible to dissolve the waste quickly and effectively, and to prevent damage to the pump.
[0037]
Furthermore, since the waste thrown into the vortex chamber can be completely dissolved before reaching the pump, a conventional culvert portion is not required. Therefore, it is possible to reduce the size of the melting furnace and eliminate regular cleaning of the culvert. .
[0041]
According to the first aspect of the present invention, since the lower part of the vortex chamber is a tapered wall having a substantially inverted conical section, a stronger spiral flow can be formed. Thereby, the thrown-down waste can be dissolved more quickly, and when the pump is used, damage to the pump can be prevented more reliably and economic efficiency can be further improved.
[0042]
Furthermore, according to the invention described in claim 2 , since the molten metal is supplied to the upper end portion of the tapered wall through the guide path, a strong spiral flow can be smoothly formed by the tapered wall, Thereby, when a pump is used, damage to the pump can be prevented in advance, and waste oxidation loss can be reduced, thereby further improving economic efficiency.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing a non-ferrous metal scrap melting furnace according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a main part of the nonferrous metal scrap melting furnace according to the embodiment of the present invention.
FIG. 3 is a plan view showing a vortex chamber of the melting furnace in FIG. 1;
4 is a cross-sectional view taken along line AA in FIG.
FIG. 5 is a longitudinal sectional view showing a main part of another nonferrous metal scrap melting furnace according to an embodiment of the present invention.
FIG. 6 is a longitudinal sectional view showing a main part of a nonferrous metal scrap melting furnace according to a conventional example.
FIG. 7 is a longitudinal sectional view showing a vortex chamber of a nonferrous metal scrap melting furnace according to another conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vortex chamber 1a Tapered wall 1b Vertical wall 1c Discharge port 2 Temperature rising chamber 3 Pump 4 Guide path 5 Flow path 5a Ascending surface 6 Burner 10 Vortex chamber 10a Vertical surface 11 Dark gutter part 11b Discharge port 20 Vortex chamber 20a Inclined wall 21 Upward flow Channel 22 Discharge port M Molten metal S Surface

Claims (2)

In a melting furnace equipped with a heating chamber equipped with a burner for heating the molten metal, a vortex chamber into which non-ferrous metal scraps are charged, and a pump for circulating the molten metal,
The vortex chamber is provided near the downstream side of the pump and upstream of the temperature raising chamber, and a discharge port provided in the lower part of the vortex chamber is provided in the molten metal at a position lower than the surface of the temperature rising chamber. In addition, the lower part of the vortex chamber has a substantially inverted conical shape by a tapered wall, and the rising surface in which the bottom surface of the flow path from the discharge port of the pump to the vortex chamber is inclined toward the vortex chamber side With the discharge force of the pump, the molten metal is spirally supplied from the pump outlet through the rising surface to a vortex chamber from a level higher than the hot water surface of the heating chamber, and from the vortex chamber to the heating chamber A non-ferrous metal scrap melting furnace characterized by being supplied to a position lower than the molten metal surface. The non-ferrous metal scrap melting furnace according to claim 1 , wherein the molten metal is supplied to an upper end portion of the tapered wall through a spiral guide path.

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