JP2009192184A - Aluminum melting furnace, heat treatment apparatus, and casting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum melting furnace, heat treatment apparatus, and casting system capable of carrying out even heating in a short time and effectively using heat without discharging carbon dioxide. <P>SOLUTION: The aluminum casting system 10 is composed of a superheated steam producing part 20, a melting furnace 32, the aluminum melting furnace 30 equipped with a holding furnace 70, a casting device 100, and the heat treatment apparatus 110. The melting furnace 32 is equipped with a spiral fin for forming a passage of superheated steam in a heating chamber surrounding a crucible. The superheated steam introduced into the heating chamber rises while rotating around a periphery of the crucible, and evenly heats the whole of the crucible to obtain high quality molten metal. The superheated steam recovered from the melting furnace 32 is sent to an auxiliary heater 90 and the holding furnace 70. The superheated steam used by the holding furnace 70 is recovered and heated by a temperature control unit 94, and it is sent to a die temperature controller 102 of the casting device 100 and treatment chambers 112A-112C of the heat treatment apparatus 110 and recycled. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an aluminum melting furnace, a heat treatment apparatus, and a casting system, and more specifically to an aluminum melting furnace, a heat treatment apparatus, and a casting system using superheated steam.

  Conventionally, an aluminum molded article is manufactured by melting an aluminum material in a melting and holding furnace to obtain a molten metal, pumping out the molten metal and manufacturing it with a casting machine, followed by heat treatment. There are two types of aluminum melting furnaces: a direct heating (direct fire) structure and an indirect heating structure. In a direct heating type melting furnace, a material to be melted (such as an aluminum piece) is heated by a heating burner provided in a melting chamber, and the material to be melted is melted by a flame sprayed from the heating burner and heat storage in the melting chamber. The molten metal obtained by melting the material to be melted is stored in a holding furnace having a heat retaining function and pumped out when necessary.

As such a direct heating type, for example, there is an aluminum alloy melting furnace shown in Patent Document 1 below. In the indirect heating type, there is a melting furnace provided with a crucible in the furnace body, and the crucible is heated from the outside with a heating burner to melt the aluminum solid inside. As such an indirect heating type, for example, a low melting point metal continuous melting and holding apparatus using a crucible furnace as a prototype shown in Patent Document 2 below is disclosed. Furthermore, as a manufacturing technique of an aluminum casting product, there are a casting product manufacturing apparatus and a casting product manufacturing method shown in Patent Document 3 below.
Japanese Patent Application Laid-Open No. 7-146073 Japanese Patent Laid-Open No. 10-332272 JP 2006-15367 A

  However, the above background art has the following disadvantages. First, in a direct-fired melting furnace, the yield of molten metal decreases due to the formation of oxides, and hydrogen gas generated by decomposition of moisture in the air is mixed in, so a high-quality molten metal is obtained. It is difficult. In addition, in the indirect heating type melting furnace, the material to be melted is generally melted out from the portion of the heating burner that hits the flame, so that it is difficult for the heat to turn uniformly to the upper part of the crucible and it takes time to melt. is there.

  In the conventional aluminum casting technique described above, the molten aluminum pumped out from the holding furnace is often transported to a casting means (die casting machine) using a transportation means such as a carriage or a forklift. For this reason, in addition to the inconvenience of taking time and labor for transportation, there is a possibility that the molten metal at high temperature may be applied to the operator when the container of the molten metal falls during transportation. The inconvenience becomes more noticeable as the number of casting means increases. Furthermore, in the technique described in Patent Document 3, since different heat sources are used for melting, casting, and heat treatment of aluminum, the facilities become complicated. In addition, the casting in the fluidized bed is heat-treated by raising the temperature of the fluidized bed composed of the granular material filled in the furnace body by a heating unit that blows hot air into the furnace body. Therefore, there is a disadvantage that the temperature is uneven in the portion close to and far from the heating portion and it is difficult to uniformly heat the entire cast product.

  The present invention focuses on the above points, and its purpose is to provide an aluminum melting furnace, a heat treatment apparatus, and a casting system that can perform heating uniformly in a short time without discharging carbon dioxide. is there. Another purpose is to recycle the heat used to dissolve the aluminum.

  In order to achieve the above object, an aluminum melting furnace of the present invention comprises superheated steam generating means for heating water, hot water or steam to generate superheated steam, a crucible having a melt inlet and a melt outlet, A furnace which surrounds the crucible and forms a heating chamber around the crucible, and includes a through-hole of a hot water pipe connected to an inlet and an outlet of the superheated steam obtained from the superheated steam generating means and an outlet of the molten metal And the whole crucible is heated by superheated steam sent to the heating chamber.

  One of the main forms is a spiral arrangement around the crucible in the heating chamber, and has superheated steam guide means for forming a passage for the superheated steam, and has an inlet and an outlet for the superheated steam. It is provided in the passage.

  Another embodiment includes a storage unit that stores the molten metal sent from the tapping pipe, and a holding furnace having a heating unit that heats the storage unit and holds aluminum as the molten metal, and the heating unit. Is characterized in that the storage means is heated using superheated steam sent from the superheated steam generation means or superheated steam recovered from the heating chamber.

  Still another embodiment is characterized in that a preheating means for preheating the material to be melted put into the crucible is provided, and the preheating means uses superheated steam recovered from the heating chamber.

  An aluminum heat treatment apparatus according to the present invention is a heat treatment apparatus for heat-treating an aluminum cast product formed by a casting apparatus, and includes a treatment chamber for performing a desired heat treatment on the cast product, and supplying superheated steam to the treatment chamber. Thus, the entire cast product is heat treated. One of the main forms is characterized in that a plurality of the processing chambers are provided, and the temperature of each processing chamber is individually set to perform any one of quenching, tempering, and annealing.

  An aluminum casting system according to the present invention includes the aluminum melting furnace according to any one of claims 1 to 4, a mold, and a temperature adjusting means for the mold, and is cast from the molten metal obtained in the aluminum melting furnace. A casting apparatus for forming a product, and the aluminum heat treatment apparatus according to claim 5 or 6, wherein the temperature adjusting means of the casting apparatus and the heat treatment apparatus are recovered from a heating chamber or a holding furnace of the aluminum melting furnace. Heating is performed using steam. One of the main forms is characterized in that the aluminum melting furnace is arranged close to or integrated with the casting apparatus. The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

  The present invention introduces superheated steam into a heating chamber formed between the crucible and the furnace body, and uniformly heats the entire crucible, so that impurities can be mixed in a short time without discharging carbon dioxide. A small amount of high-quality molten aluminum can be obtained. Moreover, by using superheated steam for the heat treatment of the aluminum casting, it is possible to uniformly heat the casting of any shape. Furthermore, by using the exhaust heat of superheated steam used for melting aluminum for heating the holding furnace, adjusting the temperature of the mold of the casting equipment, and heat-treating the cast product, it is possible to effectively use the heat. can get.

  Hereinafter, the best mode for carrying out the present invention will be described in detail based on examples.

  First, Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing an overall configuration of an aluminum casting system according to the present embodiment. FIG. 2 is a cross-sectional view showing the configuration of the aluminum melting furnace of this embodiment. FIG. 3 is a diagram showing a modification of this embodiment. As shown in FIG. 1, the aluminum casting system 10 of the present embodiment is composed of a superheated steam generator 20, an aluminum melting furnace 30, a casting apparatus 100, and a heat treatment apparatus 110, and solid aluminum (including an aluminum alloy). A series of processes from melting to casting and heat treatment are performed. The superheated steam generation unit 20 generates superheated steam by heating water, warm water or water vapor, and various types of known structures can be used.

  Next, the aluminum melting furnace 30 will be described with reference to FIG. The aluminum melting furnace 30 of this embodiment includes a melting furnace 32 that melts solid aluminum 52 (such as an aluminum ingot) and a holding furnace 70 that stores the molten metal 54 obtained by the melting furnace 32 in the molten state. It is comprised by. First, the melting furnace 32 includes a crucible 40 inside the furnace body 34. A bottom surface 40C of the crucible 40 is fixed on a refractory support base 38 provided on the bottom surface 34A of the furnace body 34. The crucible 40 has an upper end 40A open, and a discharge port 42 for discharging the molten metal 54 at a predetermined position on the side surface 40B. The furnace body 34 has, for example, a structure in which a heat insulating material 36B is provided inside the outer wall 36A.

  A heating chamber 44 for introducing the superheated steam 62 is formed between the furnace body 34 and the crucible 40. That is, dimensions are set in advance so as to form a predetermined space between the furnace body 34 and the crucible 40. In the heating chamber 44, spiral fins 60 are provided around the crucible 40. The fin 60 is for forming a passage through which the superheated steam 62 introduced into the heating chamber 44 rises while rotating around the crucible 40. Below the side surface 34B of the furnace body 34, an inlet 46 for superheated steam connected to the pipe L1 is provided. The upper side of the side surface 34B is connected to the discharge ports 48A and 48B for drawing out the pipes L2 and L3 for discharging the superheated steam 62 in the heating chamber 44 and the discharge port 42 of the crucible 40. An opening for drawing out the hot water discharge pipe 64 is formed.

  A substantially ring-shaped seal member (or lid) 50 is provided at the upper portion of the melting furnace 32 to close the space between the upper end 34C of the furnace body and the upper end 40A of the crucible. The upper end in 44 is sealed, and it is difficult for the vapor to leak to the outside. On the seal member 50, a substantially ring-shaped ring plate 56 having a charging port 58 for charging the solid aluminum 52 and a lid (not shown) are provided. The ring plate 56 and the lid may be provided as necessary, and the seal member 50 may also serve as the ring plate 56 by adjusting the inner diameter of the seal member 50. . The support base 38, the crucible 40, and the fin 60 are made of, for example, iron.

  When the superheated steam 62 is introduced into the heating chamber 44 from the introduction port 46, the superheated steam 62 rises in the heating chamber 44 along the spiral passage formed by the fins 60. That is, ascending around the crucible 40, the entire crucible 40 is heated uniformly. In this embodiment, the superheated steam 62 used in the heating chamber 44 is recovered from the discharge ports 48A and 48B, and the pipe L2 connected to one of the discharge ports 48A is as shown in FIGS. The superheated steam recovered from the heating chamber 44 is used in the holding furnace 70. Further, the pipe L3 connected to the other outlet 48B is connected to the preheater 90 as shown in FIG. The preheating machine 90 is for preheating the solid aluminum 52 before putting it into the crucible 40, and is connected to an automatic charging machine 92. The superheated steam sent to the preheating machine 90 by the pipe L3 is used for preheating the solid aluminum 52.

  Next, the holding furnace 70 will be described. The holding furnace 70 stores a molten metal 54 obtained by melting the solid aluminum 52 in the melting furnace 32, and a crucible 74 for storing the molten metal 54 is provided inside a furnace body 72 having heat insulation properties. It is the composition which was made. A steam chamber 80 through which superheated steam passes is formed between the furnace body 72 and the crucible 74. A substantially ring-shaped seal member 76 for closing the upper portion of the steam chamber 80 is provided at the upper ends of the furnace body 72 and the crucible 74. The molten metal 54 sent from the discharge pipe 64 of the melting furnace 12 is charged into the crucible 74 from the charging port 78 provided in the seal member 76. In order to maintain the molten metal 54 stored in the crucible 74 as it is, the crucible 74 needs to be heated to a predetermined temperature or higher. In the present embodiment, a steam inlet 82 for connecting to the pipe L2 is provided on the side surface of the furnace body 72, and a steam outlet 84 for discharging superheated steam is provided. A pipe L <b> 5 is connected to the steam discharge port 84, and steam discharged through the pipe L <b> 5 is sent to the temperature adjustment unit 94. Further, an opening 88 through which the tapping pipe 86 connected to the crucible 74 can pass is formed at a predetermined position on the side surface of the furnace body 72. With such a configuration, the superheated steam recovered from the melting furnace 32 is reused for heating the holding furnace 70.

  Next, the casting apparatus 100 will be described. The casting apparatus 100 is an apparatus for casting a molten metal 54 obtained in the aluminum melting furnace 30 to form a cast product having a desired shape, and adjusts a mold (not shown) and the temperature of the mold. A mold temperature controller 102 is provided. Such a casting apparatus 100 is connected to the holding furnace 70 of the aluminum melting furnace 30 by a pipe L5, and the pipe L5 is provided with a temperature adjustment unit 94 for heating superheated steam. The pipe L5 branches to the casting apparatus 100 at the pipe L6 and supplies superheated steam to the mold temperature controller 102. The configuration of the casting apparatus 100 is basically the same as that of a known casting apparatus except that superheated steam is supplied to the mold temperature controller 102.

  The cast product molded by the casting apparatus 100 is conveyed to the heat treatment apparatus 110 by the conveyor 104 or the like. In the present embodiment, the heat treatment apparatus 110 includes three processing chambers 112A to 112C, to which pipes L7a to L7c branched from the pipe L5 are connected. That is, by supplying superheated steam into the processing chambers 112A to 112C, the cast products in the processing chambers 112A to 112C can be uniformly heated and subjected to heat treatment. The processing chambers 112A to 112C can be set to different temperatures for each chamber. In this embodiment, the processing chamber 112A is about 550 ° C., the processing chamber 112B is 120 ° C., and the processing chamber 112C is 230 ° C. It is set to ℃. When heating is performed sequentially in these processing chambers 112A to 112C, the cast aluminum product can be quenched. The processing chambers 112A to 112C are provided with a superheated steam discharge port or recovery port (not shown).

  Next, the operation of this embodiment will be described. First, the superheated steam generated by the superheated steam generation unit 20 is adjusted to a desired temperature with a heater (not shown) and then sent to the heating chamber 44 of the melting furnace 32. Then, the superheated steam that has passed through the heating chamber 44 is divided into two, and one is sent to the preheating machine 90 and the other is sent to the steam chamber 80 of the holding furnace 70. After the superheated steam sent to the steam chamber 80 is collected in the pipe L5, the temperature is adjusted by the temperature adjusting unit 94, and then the mold temperature controller 102 of the casting apparatus 100 and the processing chambers 112A to 112A of the heat treatment apparatus 110 are processed. 112C. Thus, after the superheated steam is passed through the entire system, an appropriate amount of solid aluminum 52 is charged into the crucible 40 from the charging port 58. Then, the superheated steam 62 introduced into the heating chamber 44 rises while rotating around the crucible 40 along the fins 60, so that the entire crucible 40 is uniformly heated.

  The molten metal 54 obtained by melting the solid aluminum 52 is sent from the discharge port 42 of the crucible 40 through the hot water discharge pipe 64 to the holding furnace 70. When the molten metal 54 in the crucible 40 becomes a certain amount or less, the solid aluminum 52 is additionally charged as necessary. On the other hand, in the holding furnace 70 to which the molten metal 54 is sent from the melting furnace 32, the molten metal 54 is charged into the crucible 74 from the charging port 78 and stored. Further, superheated steam 62 is sent from the pipe L2 to the steam chamber 80 formed around the holding furnace 70. Although the temperature of the superheated steam 62 is slightly lowered, the superheated steam 62 has a temperature at which the crucible 74 can be heated to maintain the aluminum in the molten metal 54 state. Of course, not only the reused superheated steam but also other heating means may be used together to keep the crucible 74 warm, and as shown by the dotted line in FIG. The generated superheated steam may be sent directly to the holding furnace 70 without going through the melting furnace 32. The superheated steam whose temperature has been reduced by keeping the temperature of the crucible 74 is recovered from the steam outlet 84 near the bottom of the furnace body 72 to the pipe L5 and sent to the temperature adjustment unit 94 to be reheated.

  Then, the molten metal 54 in the crucible 74 is pumped out of the hot water discharge pipe 86 to the outside as needed, and is carried to the casting machine 100 to be used for casting of an aluminum molded product. The temperature of the mold used for casting is adjusted by sending the superheated steam reheated by the temperature adjusting unit 94 to the mold temperature controller 102. The cast product formed by the casting machine 100 is then conveyed to the heat treatment apparatus 100 by the conveyor 104 or the like, and is sequentially supplied to the process chambers 112A to 112C by passing through the three process chambers 112A to 112C. Quenching and tempering is performed by the superheated steam.

Thus, according to the first embodiment, there are the following effects.
(1) By introducing superheated steam 62 into the heating chamber 44 formed between the crucible 40 and the furnace body 34 of the melting furnace 32 and heating the entire crucible 40, the carbon dioxide is not exhausted and the carbon dioxide is discharged. It is possible to obtain a high-quality molten aluminum 54 that is less contaminated with time.
(2) Since the spiral fin 60 is provided around the crucible 40 to form the passage of the superheated steam 62, the superheated steam 62 rises while rotating around the crucible 40. It can heat more uniformly.

(3) Since the superheated steam 62 recovered from the heating chamber 44 of the melting furnace 32 is sent to the preheating machine 90 for preheating the solid aluminum 52 to be charged into the melting furnace 32, effective use of heat can be achieved. It becomes possible.
(4) Since the holding furnace 70 for storing the molten metal 54 is provided and the superheated steam 62 recovered from the melting furnace 32 is used for heating the holding furnace 70, the heat can be effectively used.

(5) Since the superheated steam 62 recovered from the holding furnace 70 is sent to the mold temperature controller 102 of the casting machine 100, the heat can be effectively used.
(6) Since the superheated steam 62 recovered from the holding furnace 70 is sent to the processing chambers 112A to 112C of the heat treatment apparatus 110, it is possible to effectively use heat, and uniform casting products with complex shapes are also possible. Heat treatment can be performed.
(7) Since the superheated steam is used without using a flame for melting the solid aluminum 52, maintaining the temperature of the molten metal, adjusting the temperature of the mold, and heat-treating the cast product, a high explosion-proof property can be obtained.

  FIG. 3 shows a modification of this embodiment. In the aluminum casting system 10 shown in FIG. 1, since the aluminum melting furnace 30 and the casting apparatus 100 are installed apart from each other, the molten metal 54 drawn out from the holding furnace 70 is transferred by a conveying means such as a carriage or a forklift. Need to carry up. On the other hand, in the example shown in FIG. 3, the aluminum melting furnace 30 including the melting furnace 32 and the holding furnace 70 is arranged close to the casting apparatus 100 to form a unit, so that the molten metal 54 pumped from the holding furnace 70 is used. The effect of eliminating the need for long distance conveyance is obtained. Furthermore, it is possible to improve safety during conveyance, and it is also possible to reduce heat loss by suppressing the temperature drop of the molten metal 54.

In addition, this invention is not limited to the Example mentioned above, A various change can be added in the range which does not deviate from the summary of this invention. For example, the following are also included.
(1) The shape, size, and material in the first embodiment are examples, and can be appropriately changed as necessary.
(2) The furnace bodies 34 and 72 in the first embodiment are also examples, and may be appropriately changed as necessary. For example, in the first embodiment, the superheated steam inlet 46 is provided below the furnace body 34 and the superheated steam 62 is raised from the lower side of the heating chamber 44. However, since the superheated steam is pushed out by pressure, It is also possible to descend from the introduction port provided in.
(3) The superheated steam generator 20 may have various known configurations as long as it can generate superheated steam.
(4) The holding furnace 70 is also an example, and may be provided as necessary. For example, when the melting furnace 32 itself is used as a holding furnace for the molten metal 60 after the aluminum 52 is melted, the holding furnace 70 can be omitted.
(5) The aluminum dissolved in this embodiment may be solid, and may be applied not only to ingots but also to dissolution of aluminum products and the like.

  According to the present invention, the superheated steam is introduced into the heating chamber formed between the crucible and the furnace body, and the entire crucible is uniformly heated, so that the impurities can be removed in a short time without discharging carbon dioxide. Since it is possible to obtain a high-quality molten aluminum with little contamination, it can be applied to an aluminum melting furnace. Moreover, since the casting can be heated uniformly by using superheated steam for the heat treatment of the aluminum casting, it can be applied to the use of a heat treatment apparatus. In addition, since the exhaust heat of superheated steam used for melting aluminum can be used for heating the holding furnace, adjusting the temperature of the mold of the casting equipment, and heat treating the cast product, the heat can be effectively used. Applicable to casting system applications.

It is a figure which shows the whole structure of Example 1 of this invention. It is sectional drawing which shows the structure of the aluminum melting furnace of the said Example 1. FIG. It is a figure which shows the principal part of the modification of the said Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Aluminum casting system 20: Superheated steam production | generation part 30: Aluminum melting furnace 32: Melting furnace 34: Furnace body 34A: Bottom surface 34B: Side surface 34C: Upper end 36A: Outer wall 36B: Thermal insulation material 38: Support stand 40: Crucible 40A: Upper end 40B: Side surface 40C: Bottom surface 42: Discharge port 44: Heating chamber 46: Inlet port 48A, 48B: Discharge port 50: Seal member 52: Solid aluminum 54: Molten metal 56: Ring plate 58: Inlet port 60: Fin 62: Overheating Steam 64: Outlet pipe 70: Holding furnace 72: Furnace body 74: Crucible 76: Seal member 78: Input port 80: Steam chamber 82: Steam inlet port 84: Steam outlet port 86: Outlet tube 88: Opening portion 90: Preheating Machine 92: Automatic feeding machine 94: Temperature adjustment unit 100: Casting apparatus 102: Mold temperature controller 104: Conveyor 110: Heat treatment apparatus 1 2A~112C: processing chamber L1~L5, L6, L7a~L7c: piping

Claims (8)

Superheated steam generating means for generating superheated steam by heating water, hot water or steam,
A crucible having an inlet for melted material and an outlet for molten metal;
A heating chamber is formed around the crucible and includes a through-hole of a hot water pipe connected to an inlet and an outlet of superheated steam obtained from the superheated steam generation means and an outlet of the molten metal. Furnace body,
With
An aluminum melting furnace characterized in that the entire crucible is heated by superheated steam sent to the heating chamber. Superheated steam guide means that is spirally disposed around the crucible in the heating chamber and forms a passage for the superheated steam;
With
The aluminum melting furnace according to claim 1, wherein an inlet and an outlet for the superheated steam are provided in the passage. A holding furnace having a storage means for storing the molten metal sent from the outlet pipe, and a heating means for heating the storage means to hold the aluminum as a molten metal;
With
The said heating means heats the said storage means using the superheated steam sent from the said superheated steam generation means, or the superheated steam collect | recovered from the said heating chamber, The said storage means is characterized by the above-mentioned. Aluminum melting furnace. A preheating means for preheating the material to be put into the crucible;
And providing
The aluminum melting furnace according to any one of claims 1 to 3, wherein the preheating means uses superheated steam recovered from the heating chamber. A heat treatment apparatus for performing heat treatment of an aluminum cast product formed by a casting apparatus,
An aluminum heat treatment apparatus comprising a treatment chamber for performing a desired heat treatment on the cast product, and performing heat treatment on the entire cast product by supplying superheated steam to the treatment chamber.   6. The aluminum heat treatment apparatus according to claim 5, wherein a plurality of the treatment chambers are provided, and any one of quenching, tempering, and annealing is performed by individually setting the temperature of each treatment chamber. An aluminum melting furnace according to any one of claims 1 to 4,
A casting apparatus having a mold and temperature control means for the mold, and molding a cast product from the molten metal obtained in the aluminum melting furnace;
The aluminum heat treatment apparatus according to claim 5 or 6,
With
An aluminum casting system, wherein the temperature adjusting means of the casting apparatus and the heat treatment apparatus heat using superheated steam recovered from a heating chamber or a holding furnace of the aluminum melting furnace.   8. The aluminum casting system according to claim 7, wherein the aluminum melting furnace is disposed close to or integrated with the casting apparatus.

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