JPH0311677Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a crucible furnace for melting nonferrous metals such as copper alloys using a crucible.

BACKGROUND ART FIG. 8 shows typical prior art. A burner 3 is arranged within a combustion chamber 2 within the furnace body 1 . A crucible 4 for melting and storing copper alloy or the like is disposed in the combustion chamber 2. An opening 5 is formed directly above the crucible 4. An ingot 6 such as a copper alloy is inserted into the crucible 4 through the opening 5 to obtain a molten metal.

In such prior art, exhaust gas and flame are discharged from the opening 5, resulting in an extremely poor working environment. In particular, when the melting of the ingot 6 progresses to a point below the opening 5, a large flame rises from the opening 5, the surrounding temperature becomes high, and the working environment is greatly deteriorated.

Another problem with this prior art is that when the exhaust gas is discharged through the opening 5, it may be absorbed by the molten metal in the crucible 4, leading to a decrease in quality.

FIG. 9 is a cross-sectional view of another prior art. A burner 3 is arranged in a combustion chamber 2 formed in a furnace body 1, and the ingot in a crucible 4 is melted. A single opening 7 is formed in the upper side of the combustion chamber 2 and the exhaust gases from this opening 7 are discharged via a flue 8.

In this prior art, compared to the prior art described in connection with FIG. 8, it is not possible to preheat the ingot using exhaust gas. Therefore, it takes time to melt the ingot, and the fuel usage efficiency, that is, the fuel consumption rate cannot be improved. Furthermore, since the exhaust gas is discharged from a single opening 7, the opening 7
The part of crucible 4 that faces the area becomes locally high in temperature,
Easy to damage. Therefore, in order to change the portion of the crucible 4 facing the opening 7, it is necessary to turn the crucible 4 around the vertical axis and angularly displace it, which impairs work efficiency.

Other conventional examples include Utility Model Publication No. 50-18970 and Utility Model Publication No. 50-22968. These have a generally cylindrical furnace body that constitutes a combustion chamber in which a crucible is placed, and a flue is formed along the circumferential direction at the upper end of the furnace body, and this flue communicates with the outside. has been done. Further, a furnace lid is mounted on the upper end of the furnace body.

In these other two conventional examples, when the flue that guides exhaust gas to the outside deteriorates and is damaged due to use, when replacing it,
It is necessary to replace the entire furnace body that constitutes the flue. Such replacement work requires a lot of effort and has the problem that the work process is extremely complicated.

Problems to be solved by the invention The purpose of the invention is to solve the above technical problems,
The work environment is good, gas absorption of molten metal can be prevented as much as possible, metal can be melted quickly, damage to crucibles etc. can be prevented from being damaged, and exhaust gas can be reduced. It is an object of the present invention to provide an improved crucible furnace that is extremely easy to repair or replace when a member constituting a path for exhaust gas guided to the outside is damaged.

Means for Solving the Problems The present invention provides a combustion chamber 12 in which a crucible 15 is placed.
A gas burner 13 is installed at the bottom of this combustion chamber 12.
a groove member 16 provided in the upper part of the furnace body 11 and having an annular groove 21 open upward; A notch 23 extending radially outward is formed, and when the groove member 16 is placed on the groove member 16, the groove 23 is partially exposed upward through the notch 23, and an exhaust gas outlet 24 is formed. a cover member 18 to be formed;
A furnace lid 19 having an opening 20 smaller in diameter than the furnace lid 19, a lid 35 that closes the opening 20 of the furnace lid 19, one end communicating with the groove 21 of the groove member 16, and a heat exchanger 29 at the other end. is provided, and a groove 2 is provided between both ends.
Damper 3 for communicating/blocking exhaust gas from 1
This crucible furnace is characterized in that it includes a flue 28 in which a gas burner 4 is provided, and a pipe line 31 that guides air heated by a heat exchanger 29 to the gas burner 13.

Effect According to the present invention, the combustion chamber 12 is provided with a central opening 22 that can be opened and closed directly above the crucible 15, and therefore the crucible 1 opens the central opening 22.
A metal block, such as an ingot, can be inserted into the hole 5. When the metal mass is inserted through the central opening 22, the exhaust gases of the combustion chamber 12 and further the flame are discharged from the open central opening 22, and the crucible 15
The upper part is sufficiently heated and the metal mass is heated, thus increasing the dissolution rate. At this time, the exhaust gas path from the outlet 24 to the groove 21 and the flue 28 is blocked.

When the melting of the metal lump progresses, the central port 22 is closed, and a path for exhaust gas from the discharge port 24 to the groove 21 and the flue 28 is opened. As a result, exhaust gas within the combustion chamber 12 is discharged from the exhaust port 24 formed on the upper side of the combustion chamber 12 and guided to the groove 21 . Since the discharge ports 24 are formed at intervals in the circumferential direction, the exhaust gas does not cause a so-called shot pass, and therefore the crucible 15 is prevented from being locally heated. At this time, the central opening 22 is closed, preventing the working environment from becoming worse. Matata Crucible 15
Gas absorption into the molten metal inside can be suppressed as much as possible.

The high temperature exhaust gas led into the groove 21 from the discharge port 24 and further the flame pass through the heat exchanger through the flue 28, thereby recovering heat and achieving an energy saving effect. . Furthermore, if the discharge port 24 and the groove 21 are deteriorated and damaged due to use, at least one of the groove member 16 and the cover member 18 may be selectively repaired and replaced.
This greatly simplifies the repair and replacement work of the crucible furnace.

Embodiment FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.
FIG. 2 is a horizontal sectional view taken along the section line - in FIG. 1. A combustion chamber 12 is formed in the furnace body 11 of the metal melting furnace, and a gas burner 13 is arranged in the lower part of the combustion chamber 12. A platform 14 is arranged in the center of the combustion chamber 12, and a crucible 15 is mounted on the platform 14. Combustion chamber 1
2 includes a right cylindrical portion 12a and a truncated conical portion 12b which is concentric with the right cylindrical portion 12a and extends above the right cylindrical portion 12a, and whose diameter becomes smaller as it goes upward.

The upper part of the furnace body 11 has an annular groove member 16,
This groove member 16 is surrounded by an outer surrounding member 17. The upper end of the groove member 16 is partially covered by a cover member 18. A furnace lid 19 is mounted on the cover member 18. This furnace lid 19 has an opening 2
0 is formed. The opening 20 has the same axis as the combustion chamber 12 and is directly above the crucible 15 .

FIG. 3 is a perspective view of the groove member 16 and the cover member 18. The groove member 16 has an annular upwardly open groove 21 for guiding the exhaust gas and is concentric with the combustion chamber 12 . A cover member 18 that partially covers the upper portion of the groove member 16 has a central opening 22 and circumferentially spaced apart and radially outwardly extending notches 23 .

FIG. 4 is a simplified sectional view taken along the section line - in FIG. 1. The shaded portion indicates the groove 21. By mounting the cover member 18 concentrically on the groove member 16, the notch 23 is aligned with the groove 2.
1 is partially exposed upward, and the exhaust gas outlet 2 is opened.
form 4. The protruding portion 25 that protrudes inward in the radial direction between the notches 23 of the cover 18 member is connected to the groove member 1.
Covers the groove 21 of No. 6.

The recess 26 formed in the outer peripheral wall of the groove member 16 is
It is connected to a flue 28 through a passage 27 formed in the outer surrounding member 17. A heat exchanger 29 is interposed in the middle of this flue 28. Combustion air is forced into the heat exchanger 29 by a fan 30.
At 9, the combustion air is heated by exhaust gas. The heated combustion air is supplied to the burner 13 through the pipe line 31. With this, flue 2
Heat is recovered from the exhaust gas passing through the exhaust gas 8 and also from the flame, improving thermal efficiency and achieving an energy saving effect.

A damper 34 is provided in the middle of the flue 28, so that the flue 28 can be blocked.

On the furnace cover 19, there is a preheating cylinder 32 concentric with the opening 20.
is removably mounted.

When melting ingots of non-ferrous alloys such as copper alloys, the furnace lid 1 is
Place the preheating tube 32 on top of the flue 28 in this state.
damper 34 is cut off. An ingot 36 is inserted into the crucible 15 through the opening 20. The exhaust gas and flame from the combustion chamber 12 thus heat the crucible 15 and are discharged upwardly through the opening 20 as indicated by the arrow 33. As a result, the ingot 36 inserted through the opening 20 is heated. The preheating tube 32 directs the exhaust gas and flame from the opening 20 upward, thereby allowing the ingot 36 to be heated efficiently. As the melting of the ingot 36 progresses, new ingots are added through the opening 20.

After the ingot 36 to be melted is below the opening 20 as the melting progresses, the preheating tube 32 is removed, the lid 35 is placed on the furnace lid 19, and the ingot 36 is placed under the opening 20.
block. At the same time, the damper 34 of the flue 28 is opened. As a result, the exhaust gas from the combustion chamber 12,
Furthermore, as shown by arrow 37, the flame is in the crucible 1.
5 is led to the outlet 24 and the groove 21,
Follow the flue 28 from the passage 27. In this way, a molten metal 38 is obtained within the crucible 15.

Since the opening 20 is covered by the lid 35, exhaust gas and flames are not discharged from the opening 20, so that the working environment is good. In the state shown in FIG. 5(1), the ingot 36 is inserted through the opening 20, so the exhaust gas and flames do not spread widely and are discharged from the opening 20, resulting in a worsening of the working environment. is suppressed. The embodiment described above thus provides an improved working environment compared to the prior art described in connection with FIG.

In addition, the exhaust gas from the combustion chamber 12 is guided outward from the upper part of the crucible 15 in the state shown in FIG. Vigorous contact of the exhaust gases is therefore avoided in the molten metal 38.
gas absorption is suppressed.

Since the exhaust gas passages 24 are formed at regular intervals in the circumferential direction, the exhaust gas can be discharged from near the outer periphery of the upper end of the crucible 15 at a substantially uniform flow rate in the circumferential direction. This prevents the so-called short pass of the exhaust gas and also
5 is not locally heated, and damage to the crucible 15 is prevented.

The exhaust gas and flame from the combustion chamber 12 are as shown in Figure 5 (1).
In this state, as shown by arrow 33, the crucible comes into contact with the upper part of the crucible 15 and is discharged from the opening 20, and as shown in FIG.
In state (2), as shown by arrow 37, the crucible 15 is guided from the upper part of the crucible 15 through the central opening of the cover member 18 to the discharge port 24. This allows the entire crucible 15 to be sufficiently heated. Therefore, the dissolution rate can be improved.

The hearth 40 of the furnace body 11 includes a floor member 41 having excellent heat resistance and a coating layer 42 disposed thereon. The floor member 41 has a structure made of compressed fibrous ceramic, has excellent fire resistance, good cross-sectional properties, has a small specific gravity, is light, and has a small amount of heat storage, and therefore has an energy saving effect.

The covering layer 42 is made of a material that has excellent fire resistance, excellent thermal shock resistance against rapid heating and cooling, and extremely low thermal conductivity. As such a coating layer 42, for example, "Cryston" manufactured by Nippon Insulator Co., Ltd.
(Product name), SiC 78.0%,
_SiO2 3.0%, _{Fe2O3 0.4} %, and _{Si3N4 and}
It is a silicon carbide refractory material with a composition in which the sum of Si ₂ On ₂ is 18.0%. The covering layer 42 is formed by dividing a circular flat plate into four equal parts, and since the covering layer 42 is divided into four parts, it can be easily installed on the floor member 41. The coating layer 42 made of this refractory material is non-wetting to the molten metal and has good fluidity of the molten metal. Moreover, this refractory material has the property of being easily destroyed by impact force. Therefore, when the molten metal solidifies on the coating layer 42, it is easy to apply impact force from above the solidified metal to destroy the coating layer 42 together with the metal and take it out of the combustion chamber 12.

This coating layer 42 is formed at the lower part of the furnace body 11 and smoothly extends downward to the outlet 43 with a slight inclination. Inside the outlet 43, there is a closing member 4 made of glass fiber that has excellent fire resistance and good heat insulation properties.
4 is packed. As a result, when the crucible 15 is damaged and the molten metal flows onto the coating layer 42, the molten metal on the coating layer 42 is absorbed into the closing member 44 by its capillary action, and in particular, a large amount of the molten metal flows. When this is the case, it flows out of the furnace through the closing member 44 in the outlet 43. The outlet 43 has a shape in which the cross-sectional area becomes larger from the inside to the outside of the combustion chamber 12, so that it is easy to take out the closing member 44 that has absorbed the molten metal.

FIG. 6 is a longitudinal sectional view of another embodiment of the present invention, and FIG. 7 is a sectional view taken along the section line - in FIG. 6. This embodiment is similar to the previous embodiment, and corresponding parts are given the same reference numerals. What is noteworthy about this embodiment is that an annular exhaust member 51 is provided surrounding the upper end of the furnace body 11 and in which an annular flue 50 is formed, and the annular flue 50 and the combustion chamber 12 are communicated with each other. This is because an exhaust passage 52 is formed. The exhaust passages 52 are arranged at intervals in the circumferential direction of the furnace body 11.
Multiple forms are formed. The exhaust gas flowing through the annular flue 50 is guided to a collecting flue 53 and discharged.

A metal melting furnace having such a configuration can also perform the same melting operation as in the above-mentioned embodiment, and can obtain the same effects as described in the above-mentioned embodiment.

Effects As described above, according to the present invention, when the metal lump is inserted through the central opening 22, the exhaust gas from the combustion chamber 12 and the flame are discharged from the open central opening 22, and from the lower part of the crucible 15. The entire circumferential surface at the top is sufficiently heated, and the metal lump is heated.
Therefore, the dissolution rate is improved.

When the melting of the metal lump progresses, the central port 22 is closed, and a path for exhaust gas from the discharge port 24 to the groove 21 and the flue 28 is opened. As a result, the exhaust gas within the combustion chamber 12 is discharged from the exhaust port 24 formed on the upper side of the combustion chamber 12 and guided to the groove 21 . Since the discharge ports 24 are formed at intervals in the circumferential direction, the exhaust gas does not cause a so-called shot pass, and therefore the crucible 15 is prevented from being locally heated. At this time, the central opening 22 is closed, preventing the working environment from becoming worse. Matata Crucible 15
Gas absorption into the molten metal inside can be suppressed as much as possible.

The high temperature exhaust gas led into the groove 21 from the exhaust port 24 and further the flame pass through the heat exchanger via the flue 28, thereby recovering heat and achieving an energy saving effect. Also, the discharge port 24 and the groove 2
If 1 has deteriorated or been damaged due to use,
At least one of the groove member 16 and the cover member 18 may be selectively repaired or replaced. This greatly simplifies the repair and replacement work of the crucible furnace.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of one embodiment of the present invention, Fig. 2 is a sectional view taken from the cutting plane line - of Fig. 1, and Fig. 3 is a sectional view of an embodiment of the present invention.
The figure is a perspective view of the groove member 16 and the cover member 18,
4 is a sectional view taken from the cutting plane line - in FIG. 1, FIG. 5 is a sectional view for explaining the melting operation of the ingot 36, and FIG. 6 is a longitudinal sectional view of another embodiment of the present invention. , FIG. 7 is a sectional view taken along the cutting plane line - of FIG. 6, and FIGS. 8 and 9 are sectional views showing the prior art, respectively. 11... Furnace body, 12... Combustion chamber, 13... Burner, 15... Crucible, 16... Groove member, 18...
Cover member, 19... Furnace lid, 20... Opening, 21
... Groove, 22 ... Center opening, 23 ... Notch, 24
...Exhaust port, 28 ... Flue, 29 ... Heat exchanger,
34... damper, 40... hearth, 41... hearth member, 42... coating layer, 43... outlet, 44...
Occlusion member.

Claims (1)

[Claims for Utility Model Registration] A furnace body 11 having a combustion chamber 12 in which a crucible 15 is disposed and a gas burner 13 provided at the bottom of the combustion chamber 12; a groove member 16 in which an annular groove 21 is formed; a central opening 22 and a notch 23 extending radially outward at an interval from the central opening 22 in the circumferential direction; a cover member 18 in which the exhaust gas outlet 24 is formed by partially exposing the groove 23 upwardly through the notch 23 when mounted on the cover member 18; 22
A furnace lid 19 having an opening 20 smaller in diameter than the furnace lid 19, a lid 35 that closes the opening 20 of the furnace lid 19, one end communicating with the groove 21 of the groove member 16, and a heat exchanger 29 at the other end. is provided, and a groove 2 is provided between both ends.
Damper 3 for communicating/blocking exhaust gas from 1
A crucible furnace characterized in that it includes a flue 28 in which a gas burner 4 is provided, and a pipe line 31 that guides air heated by a heat exchanger 29 to the gas burner 13.