JP2005077077A - Melting holding furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a melting holding furnace for preventing outside air from flowing in, and preventing heat energy loss and running costs from increasing. <P>SOLUTION: This melting holding furnace 100 has a melting chamber 1 melting metal ingot 2a, and a holding chamber 3 provided with a first communication hole H1 for passing molten metal 2 formed by melting the metal ingot 2a to a first partition wall W1 dividing the hole and the melting chamber 1, and holding the molten metal 2 introduced via a first communication hole H1. An exhaust port 8h for releasing exhaust gas in the melting chamber 1 to the outside is formed at the top of the melting chamber 1, and an exhaust pipe 8 connected with the exhaust port 8h has a low arrangement portion 8i arranged at a position lower than that of the exhaust port 8h in the middle of an exhaust path. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a melting and holding furnace used for manufacturing a metal casting or the like.

  A melting and holding furnace used for manufacturing a metal casting or the like is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-223463 (Patent Document 1).

  FIG. 2 is a schematic cross-sectional view showing an example of a conventional melting and holding furnace.

  The melting and holding furnace 90 in FIG. 2 draws the melting chamber 1 for melting the metal lump 2a with the burner B1, the holding chamber 3 for keeping the molten metal 2 formed by melting the metal lump 2a with the burner B2, and the molten metal 2. It has a drawing chamber 4 for taking out. In the melting and holding furnace 90 of FIG. 2, a communication hole H1 through which the molten metal 2 can pass is provided in the partition wall W1 separating the melting chamber 1 and the holding chamber 3, and the molten metal 2 generated in the melting chamber 1 is communicated with the communication hole. It is introduced into the holding chamber 3 through H1. The partition wall W2 that partitions the holding chamber 3 and the pumping chamber 4 is provided with a communication hole H2 through which the molten metal 2 can pass, and the molten metal 2 held in the holding chamber 3 enters the pumping chamber 4 through the communication hole H2. It is introduced and pumped out from the pumping chamber 4 to be used for producing metal castings.

  In the melting and holding furnace 90 of FIG. 2, a charging port 1h for charging the metal lump 2a is provided on the upper surface of the melting chamber 1, and a charging lid 70 covers the charging port 1h. Further, the charging lid 70 is provided with an exhaust port 70h, and the exhaust gas generated in the dissolution chamber 1 is released to the outside through a tempura hood 80 that covers the entire charging port 1h and the charging lid 70.

FIG. 3 shows a melting and holding furnace 91 having another melting chamber superstructure. In the melting and holding furnace 90 of FIG. 2, the exhaust port 70 h is formed in the charging lid 70 covering the charging port 1 h, but in the melting and holding furnace 91 of FIG. 3, the charging port 1 h and the exhaust port 81 h are the upper part of the melting chamber 1. Are provided separately. Further, the charging port 1h is covered with a charging lid 71 without holes, and the exhaust port 81h is directly connected to an exhaust pipe 81 connected to the chimney.
JP-A-11-223463

  In the melting and holding furnaces 90 and 91 shown in FIGS. 2 and 3, the exhaust gas passages of the melting chamber 1 and the holding chamber 3 are directly connected to the chimney extending upward through the exhaust ports 70h and 81h. For this reason, when the combustion in the melting chamber 1 or the holding chamber 3 is stopped due to the misfire of the burners B1 and B2, etc., as shown by the thick solid line arrows in the figure, the cold and heavy specific outside air directly enters the furnace from the chimney. It flows in. If there is such inflow of outside air, the inside of the furnace is rapidly cooled and the molten metal 2 is solidified in a short time, and the life of the furnace body is reduced due to the stress. Moreover, if the holding amount of the molten metal 2 is increased to prevent the rapid solidification as described above, the heat energy loss increases and the running cost increases.

  Accordingly, an object of the present invention is to provide a melting and holding furnace having a melting chamber and a holding chamber, which prevents the flow of outside air and does not increase thermal energy loss and running cost. Yes.

  According to the first aspect of the present invention, a molten chamber formed by melting the metal lump passes through a melting chamber that melts the metal lump and a first partition that is disposed adjacent to the melting chamber and partitions the melting chamber. A melting and holding furnace provided with a first communication hole capable of holding a molten metal introduced through the first communication hole, wherein the exhaust gas in the melting chamber is externally disposed above the melting chamber. And an exhaust pipe connected to the exhaust port has a low-arrangement portion disposed lower than the exhaust port position in the middle of the exhaust path.

  According to this, the exhaust pipe has the low arrangement | positioning site | part lower than an exhaust-port position in the middle. For this reason, when combustion of a burner or the like is stopped and outside air is about to flow into the furnace, the outside air having a high specific gravity at low temperature is temporarily accumulated in the low arrangement portion formed in the exhaust pipe and has a low specific gravity at high temperature. The lid is covered with the air in the furnace, and the flow of outside air into the furnace is suppressed. Thereby, even if combustion of the burner is stopped, a rapid temperature drop in the furnace can be prevented, and a reduction in the life of the furnace body is also suppressed. Moreover, since it is not necessary to increase the holding | maintenance amount of a molten metal according to this, a thermal energy loss and a running cost do not increase.

  According to a second aspect of the present invention, in the exhaust pipe, the exhaust gas outlet at the end opposite to the exhaust port that is an exhaust gas inlet is preferably arranged higher than the exhaust port position. Thereby, the exhaust gas having a small specific gravity at a high temperature can be safely discharged outdoors.

  According to a third aspect of the present invention, it is preferable that a maintenance door is arranged at the low arrangement part or a part around the low arrangement part.

  In the exhaust pipe low arrangement portion, the high-temperature furnace air and the low-temperature outside air are mixed. For this reason, the carbon component contained in the exhaust gas from the melting chamber and the holding chamber is cooled by the outside air and becomes dust such as carbon, and is easily collected in a low-arranged portion. As described above, by arranging the maintenance door at the low placement site or around the site, it is possible to easily remove dust such as carbon accumulated during the use of the furnace for a long period of time.

  According to a fourth aspect of the present invention, a molten chamber formed by melting the metal mass passes through a melting chamber that melts the metal mass and a first partition that is disposed adjacent to the melting chamber and partitions the melting chamber. A melting and holding furnace provided with a first communication hole and a holding chamber for holding a molten metal introduced through the first communication hole, for introducing the metal mass into the upper surface of the melting chamber And a lid that covers the charging port, and the uppermost surface of the wall of the dissolution chamber located on the inner side is higher than the lowermost surface of the lid positioned on the outer side around the charging port. It is characterized by being.

  Also, the inlet for introducing the metal lump is not necessarily completely sealed. Therefore, when combustion of the burner or the like is stopped, it can be a path for inflow of outside air. However, in this case as well, in the same manner as the low arrangement portion provided in the exhaust pipe, outside air having a high specific gravity at a low temperature is temporarily accumulated between the uppermost surface of the wall of the melting chamber and the lowermost surface of the lid covering the inlet. The lid is covered with the furnace air having a low specific gravity at a high temperature, thereby preventing the outside air from flowing in. Thereby, even if combustion of the burner is stopped, a rapid temperature drop in the furnace can be prevented, and a reduction in the life of the furnace body is also suppressed. Moreover, since it is not necessary to increase the holding | maintenance amount of a molten metal according to this, a thermal energy loss and a running cost do not increase.

  As described in claim 5, the dissolution chamber is preferably formed in a tower shape. According to this, a metal lump is charged from the inlet provided on the upper surface of the tower-shaped melting chamber, the metal lump is accumulated at the center of the tower-shaped melting chamber, and the metal lump is dissolved at the lower part of the tower-shaped melting chamber. Can be made. On the other hand, the exhaust gas in the melting chamber and the holding chamber is discharged from an exhaust port provided in the upper part of the tower-shaped melting chamber. As a result, the undissolved metal mass accumulated in the central portion of the tower can be sufficiently preheated using the exhaust gas from the melting chamber and the holding chamber. As a result, the heat energy of the exhaust gas can be used effectively, and a melting and holding furnace with reduced heat energy loss and running cost can be obtained.

  According to a sixth aspect of the present invention, in the melting and holding furnace, a first burner for melting a metal lump is installed at the lower part of the melting chamber, and a first temperature for ensuring the temperature of the molten metal on the upper surface of the holding chamber. It is preferable that a two-burner is installed. According to this, since a burner having a lower running cost than an electric heater or the like can be used, and the exhaust gas of the burner can be used for preheating the metal lump as described above, a melting and holding furnace with reduced running cost can be obtained. Can do.

  According to a seventh aspect of the present invention, the melting and holding furnace is provided adjacent to the holding chamber, and is provided with a second communication hole through which the molten metal can pass through a second partition partitioning the holding chamber. It is preferable to have a pumping chamber for pumping out the molten metal introduced through the second communication hole. According to this, a series of steps from melting of the metal mass to holding and pumping of the molten metal can be performed in one melting and holding furnace, and thermal energy loss in the step is reduced.

  As described in claim 8, the melting and holding furnace is suitable for a melting and holding furnace in which the metal lump is aluminum or an aluminum alloy and melts and holds them. By using the melting and holding furnace, the running cost is reduced, and the manufacturing cost of an aluminum die cast product or the like is reduced.

  Hereinafter, the melting and holding furnace of the present invention will be described with reference to the drawings.

  FIG. 1A is a schematic cross-sectional view showing an outline of the melting and holding furnace 100 of the present invention. In the melting and holding furnace 100 of FIG. 1 (a), the same parts as those of the conventional melting and holding furnaces 90 and 91 shown in FIGS.

  The melting and holding furnace 100 of FIG. 1A is similar to the melting and holding furnaces 90 and 91 of FIGS. 2 and 3 and has a melting chamber 1, a holding chamber 3 and a pumping chamber 4 arranged adjacent to each other. It is.

  In the melting chamber 1, the metal lump 2 a introduced into the chamber is melted by the burner B <b> 1 installed at the lower part of the melting chamber 1, and the molten metal 2 is generated. In the case where the melting and holding furnace 100 of FIG. 1A is a melting and holding furnace used, for example, in the manufacture of an aluminum die-cast product, an ingot of aluminum or an aluminum alloy is put into the melting chamber 1 as the metal lump 2a and is melted. Thus, a molten aluminum 2 mainly composed of aluminum is generated. The partition wall W1 partitioning the melting chamber 1 and the holding chamber 3 is provided with a communication hole H1 through which the molten metal 2 can pass, and the molten metal 2 generated in the melting chamber 1 passes through the holding hole 3 through the communication hole H1. To be introduced.

  In the holding chamber 3, the molten metal 2 stored in the lower part of the holding chamber 3 is heated by the burner B <b> 2 installed on the upper surface of the holding chamber 3, and is kept warm and held at a constant temperature. The partition wall W2 that partitions between the holding chamber 3 and the pumping chamber 4 is provided with a communication hole H2 through which the molten metal 2 can pass, and the molten metal 2 that is kept warm and held in the holding chamber 3 passes through the communication hole H2. It is introduced into the drawing chamber 4.

  The pumping chamber 4 has a pumping outlet 4h whose upper side is opened to pump out the molten metal 2, and a pumping lid 5 that opens and closes the pumping outlet 4h. The molten metal 2 introduced into the pumping chamber 4 is opened by the pumping lid 5 and pumped out from the pumping outlet 4h to the outside by a pumping robot ladle (not shown) and carried to a die casting machine to produce a metal casting such as aluminum die casting. Is done.

  As described above, the melting and holding furnace 100 in FIG. 1A in which the melting chamber 1 is integrated with the holding chamber 3 and the pumping chamber 4 is a series of steps from the melting of the metal lump 2a to the holding and pumping of the molten metal 2. Can be performed in a single furnace, and thermal energy loss and running cost during the process are reduced. In addition, since the melting chamber 1 and the holding chamber 3 use the burners B1 and B2, which have a lower running cost than an electric heater or the like, the running cost is also reduced.

  Further, the melting chamber 1 in the melting and holding furnace 100 of FIG. As a result, the metal lump 2a is charged from the charging port 1h provided on the upper surface of the tower-shaped melting chamber 1, the metal lump 2a is accumulated in the central portion of the tower-shaped melting chamber 1, and the metal lump is formed in the lower portion of the tower-shaped melting chamber 1. 2a is dissolved. On the other hand, the exhaust gas in the dissolution chamber 1 and the holding chamber 3 is discharged to the outside through an exhaust pipe 8 from an exhaust port 8 h provided in the upper part of the tower-shaped dissolution chamber 1. By providing the exhaust port 8h in the upper part of the tower-shaped dissolution chamber 1, the pre-dissolution metal mass 2a accumulated in the center of the tower is sufficiently preheated using the exhaust gas from the dissolution chamber 1 and the holding chamber 3. can do. Thus, the thermal energy loss and the running cost are also reduced by effectively using the thermal energy of the exhaust gas.

  FIG.1 (b) is sectional drawing which expands and shows the upper part of the melting chamber 1 of Fig.1 (a). In the melting and holding furnace 100 shown in FIGS. 1A and 1B, an exhaust port 8h is provided in the upper part of the melting chamber 1, and the exhaust pipe 8 connected to the exhaust port 8h is in the middle of the exhaust path. As shown by the height difference La in 1 (b), it has a low arrangement portion 8i arranged lower than the position of the exhaust port 8h. When the combustion of the burners B1 and B2 is stopped by the height difference La and the outside air is about to flow into the furnace from the exhaust pipe 8, the outside air having a large specific gravity at a low temperature indicated by a thick solid arrow in the figure is It temporarily accumulates in the low arrangement portion 8 i formed in the exhaust pipe 8. For this reason, the low temperature and high specific gravity outside air accumulated in the low-arrangement site 8i is capped with high temperature and low specific gravity furnace air indicated by the thick dotted arrows in the figure, and enters the outside air into the furnace. Inflow is suppressed. Therefore, even if the combustion of the burners B1 and B2 is stopped, a rapid temperature drop in the furnace can be prevented, the molten metal 2 does not harden in a short time, and a reduction in the furnace life due to the stress is also suppressed. As schematically shown by the height difference Lc in FIG. 1 (b), in the exhaust pipe 8, the exhaust gas outlet 8j at the end opposite to the exhaust port 8h that is the exhaust gas inlet is higher than the position of the exhaust port 8h. Be placed. Thereby, the exhaust gas having a small specific gravity at a high temperature can be safely discharged outdoors.

  A maintenance door 9 is arranged at a low arrangement portion 8i in the exhaust pipe 8 of FIGS. 1 (a) and 1 (b). In the low arrangement part 8i of the exhaust pipe 8, as described above, the high-temperature furnace air and the low-temperature outside air are mixed. For this reason, the carbon component contained in the exhaust gas from the melting chamber 1 and the holding chamber 3 is cooled by the outside air and becomes dust such as carbon, and is easily collected in the low arrangement portion 8i. As shown in FIGS. 1 (a) and 1 (b), the maintenance door 9 is arranged in the low arrangement part 8i or a part around the low arrangement part 8i to remove dust such as carbon accumulated during the long-term use of the furnace. It can be done easily.

  The problem of inflow of outside air into the furnace when combustion of the burner stops can occur in the same way also at the charging port 1h for charging the metal lump 2a into the melting chamber 1. Since the inlet 1h of the metal lump 2a is not necessarily completely sealed, it can be a path for inflow of outside air.

  In the melting and holding furnace 100 shown in FIGS. 1 (a) and 1 (b), a charging port 1h for charging the metal lump 2a into the melting chamber 1 on the upper surface of the melting chamber 1, and a charging lid 7 covering the charging port 1h. And are provided. About the structure of the inlet 1h and the inlet lid 7, as shown by the height difference Lb in FIG.1 (b), the uppermost surface of the wall of the melting | dissolving chamber 1 located inside around the inlet 1h is outside. It is comprised so that it may exist in a position higher than the lowermost surface of the insertion lid | cover 7 which is located. Due to this height difference Lb, in this case as well, the low-temperature outside air having a large specific gravity at the low temperature indicated by the thick solid line arrow in the drawing is the same as the low arrangement portion 8i provided in the exhaust pipe 8. It temporarily accumulates between the upper surface and the lowermost surface of the charging lid 7. For this reason, the outside air having a high specific gravity at a low temperature is covered with the furnace air having a high specific gravity at a high temperature indicated by a thick dotted arrow in the figure, and the flow of the outside air into the furnace is suppressed. As a result, similar to the above, even if combustion of the burners B1 and B2 is stopped, a rapid temperature drop in the furnace can be prevented, and a reduction in the life of the furnace body is also suppressed.

  In the melting and holding furnace 100 shown in FIGS. 1 (a) and 1 (b), as described above, the low arrangement portion 8i is arranged in the exhaust pipe 8 so as to provide a difference in height La from the exhaust port 8h, and the melting chamber at the input port 1h. By simply providing a height difference Lb between the uppermost surface of the wall 1 and the lowermost surface of the charging lid 7, a rapid temperature drop in the furnace can be prevented. As described above, in the melting and holding furnace 100 shown in FIGS. 1A and 1B, it is not particularly necessary to increase the amount of the molten metal 2 held, so that thermal energy loss and running cost do not increase.

  As described above, the melting and holding furnace 100 shown in FIGS. 1 (a) and 1 (b) is a melting and holding furnace having the melting chamber 1 and the holding chamber 3, and prevents the flow of outside air and the thermal energy. It is a melting and holding furnace that does not increase loss and running costs. The melting and holding furnace 100 shown in FIGS. 1A and 1B is suitable for a melting and holding furnace in which the metal lump 2a is made of aluminum or an aluminum alloy and is melted and held. By using this melting and holding furnace 100, the running cost can be reduced, and the manufacturing cost of aluminum die cast products and the like can be reduced.

(Other embodiments)
A melting and holding furnace 100 shown in FIG. 1A is a melting and holding furnace in which a melting chamber 1, a holding chamber 3, and a pumping chamber 4 are integrated. The melting and holding furnace of the present invention is not limited to this and may be a melting and holding furnace in which the pumping chamber 4 is a separate body. Further, in the melting and holding furnace 100 of FIG. 1A, the example in which the melting chamber 1 is formed in a tower shape is shown, but the shape of the melting chamber 1 is not limited to this and may be any shape. Further, in the melting and holding furnace 100 of FIG. 1A, the burners B1 and B2 are used for melting the metal lump 2a and keeping the molten metal 2 warm, but an electric heater or the like may be used.

(A) is typical sectional drawing which shows the outline of the melting holding furnace of this invention, (b) is sectional drawing which expands and shows the upper part of the melting chamber of (a). It is typical sectional drawing which shows an example of the conventional melt | dissolution holding furnace. It is typical sectional drawing of the conventional melting holding furnace which has another melting chamber superstructure.

Explanation of symbols

90, 91, 100 Melting and holding furnace 1 Melting chamber 1h Input port 2 Molten metal 2a Metal lump 3 Holding chamber 4 Pumping chamber 7, 70, 71 Input lid 8, 81 Exhaust pipe 70h, 8h Exhaust port 8i Low arrangement site 8j Exhaust gas outlet 9 Maintenance door B1, B2 Burner H1, H2 Communication hole W1, W2 Bulkhead

Claims (8)

A melting chamber for melting the metal mass;
A first communication hole that is disposed adjacent to the melting chamber and that allows the molten metal formed by melting the metal mass to pass through is provided in a first partition wall that partitions the melting chamber, and is introduced through the first communication hole. A melting and holding furnace having a holding chamber for holding the molten metal,
In the upper part of the dissolution chamber, an exhaust port for releasing the exhaust gas in the dissolution chamber to the outside is provided,
The melting and holding furnace characterized in that the exhaust pipe connected to the exhaust port has a low-arranged portion disposed lower than the exhaust port position in the middle of the exhaust path.   2. The melting and holding furnace according to claim 1, wherein in the exhaust pipe, an exhaust gas outlet at an end opposite to the exhaust port that is an exhaust gas inlet is disposed higher than the exhaust port position.   The melting and holding furnace according to claim 1, wherein a maintenance door is arranged at the low arrangement site or a site around the low arrangement site. A melting chamber for melting the metal mass;
A first communication hole that is disposed adjacent to the melting chamber and that allows the molten metal formed by melting the metal mass to pass through is provided in a first partition wall that partitions the melting chamber, and is introduced through the first communication hole. A melting and holding furnace having a holding chamber for holding the molten metal,
On the upper surface of the melting chamber, a charging port for charging the metal lump, and a lid that covers the charging port are provided,
A melting and holding furnace, wherein the uppermost surface of the wall of the melting chamber located on the inner side is higher than the lowermost surface of the lid located on the outer side around the charging port.   The melting and holding furnace according to any one of claims 1 to 4, wherein the melting chamber is formed in a tower shape.   A first burner for melting the metal mass is installed at the lower part of the melting chamber, and a second burner for securing the temperature of the molten metal is installed on the upper surface of the holding chamber. The melting and holding furnace according to any one of claims 1 to 5. The melting and holding furnace,
A second communication hole that is disposed adjacent to the holding chamber and allows the molten metal to pass through a second partition wall that partitions the holding chamber, and pumps out the molten metal introduced through the second communication hole; The melting and holding furnace according to any one of claims 1 to 6, further comprising a pumping chamber.   The melting and holding furnace according to any one of claims 1 to 7, wherein the metal block is aluminum or an aluminum alloy.

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