KR880003772Y1 - Under-heater type furnaces - Google Patents

Abstract

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Description

Under-heater furnace

1 is a partially cutaway perspective view showing a furnace according to a first embodiment of the present invention.

2 is an enlarged cross-sectional view of the main portion of the first embodiment of the present invention.

3 is a partially cutaway perspective view showing a furnace according to a second embodiment of the present invention.

4 is an enlarged cross-sectional view of the main portion of a second embodiment of the present invention.

5 is a plan view of a furnace shown in FIGS. 1 and 3.

6 is a partial cross-sectional perspective view of the lower portion of the furnace shown in FIGS. 1 and 3.

FIG. 7 is a partial cross-sectional perspective view showing the injection portion of the furnace shown in FIGS. 1 and 3.

* Explanation of symbols for main parts of the drawings

1: molten aluminum alloy 1a: surface

2, 2 ': protective tube 2a: open end

2b: blocked end 3: refractory

4: furnace outer wall 5: heater

5 ': gas burner heater 5a: burner body

5b: pipe 5c: outlet

6: detection part 6a: lead wire

8: additional tube 8a: flange

9: tapered hole 9a: spiral

10: heat insulation layer 11: second support portion

12: sealing member 13: connecting portion

15: injection portion 15a: inner wall

15b: pipe portion 16: sensor portion

16a: protective tube 17: ceramic tube

18: partition wall 19: first compartment

20: Second division room 21: Third division room

22: small cover 23: main cover

24: ceramic fiber layer 25, 26, 27: hole

29 handle H: heating means

The present invention relates to an underheater-type furnace for holding molten metal at a high temperature. More specifically, a low melting point metal such as an aluminum alloy is subjected to slug removal treatment, for example, after die reduction and die-casting after die reduction. It relates to an underheater type furnace to be maintained at a high temperature of ℃.

Conventionally, in the form of a furnace, a gas, an oil burner or an electric heater or the like has been used to heat a molten metal such as an aluminum alloy.

In addition, conventional furnaces include an upper-heater type and an under-heater type.

Moreover, in things like an under heater type furnace, various means for fixing a heater member were employ | adopted.

For example, in the furnace of the prior art, both ends of the code tubing for enclosing the heater therein are fixed between both walls of the furnace while passing through the heater.

In another conventional underheater type furnace, one end of a protection tube for a heater is fixed to one wall of the furnace.

In the conventional fixed heater of both ends, the protective tube for enclosing the heater is likely to be broken by its thermal expansion.

In addition, the sealing member between the protective tube and the side wall of the furnace is easily broken, and its structure is complicated, which makes assembly very difficult.

Moreover, in the conventional furnace of one end fixed type, it is quite difficult to support a long protective tubing.

For that reason, even if the protective tube is inclined, the sealing member between the protective tube and one wall of the furnace is brittle, so that molten metal may leak.

Therefore, only short protective tubing is actually used, and thus the efficiency is bad.

It is therefore an object of the present invention to provide an underheater-type furnace for retaining molten metal at high temperatures, which can form a protective tubing in the heater and also prevent breakage between the tube and the furnace sidewalls. It can provide a sealing member for.

Refractory crucibles or loads are made of castable materials.

Since Si contained in the castable material reacts with AI in the molten aluminum alloy, a good castable material is mainly composed of 50 to 99% by weight of AI ₂ O _{3 and} 0.5 to 50% by weight of SiO ₂ .

From this point of view, the inner surface of the refractory crucible may be a BN coating. The insulation layer is made of ceramic fiber material with good insulation to reduce power and gas consumption. The heat insulation layer is preferably in the form of a plurality of blankets of a multi-layer structure. The heater may be a heater, a gas burner, or the like. The heater is made of well-known metal or silicon carbide, and the protective tube is made of a conventional ceramic. It is preferable that the protective tubing is a silicon carbide ceramic having good corrosion resistance and heat resistance in the case of an aluminum alloy.

When a heater made of silicon carbide or the like is inserted into the protective tubing, a filler such as ceramic fiber or magnesia powder is preferably formed between the heater and the protective tubing to prevent the leaked molten metal to a considerable extent, and the sealing member is made of fiber It is preferable that it is a mortar containing.

The refractory has a first support on the lower side wall and a second support on the opposite side wall. It is preferable that the 2nd support part makes the lower end of the side wall of a furnace into a staircase shape.

The protective tube has an open end and a blocked end, and the blocked end of the protective tube is supported by the second support so that it is not fixed and the blocked end of the protective tube is free to the second support. It is movable, and the open end part is fixed to the 1st support part. As the protective tube extends between the two side walls of the refractory, a long protective tube can be used. This increases the thermal efficiency. In the refractory, a tapered hole, which is a first support portion that extends outward, is formed on the sidewall thereof, and a tapered spiral is formed in the tapered hole, and the protective tube is penetrated through the tapered hole, so that the gap between the protective tube and the tapered hole The sealing member of mortar containing fiber is filled.

Therefore, the protective tube can be fixed by the sealing member, and the sealing portion of the sealing member is large enough to obtain a good sealing effect.

When the protective tube expands by heat, the sealing member presses against the tapered hole wall, especially against the tapered spiral, so that the sealing effect is further increased.

In addition, the sealing member can be prevented from coming off.

The open end of the protective tube is joined to one end of the additional tube of ceramic fiber material which has an insulating effect, which ends at the outside of the refractory and extends through the insulating layer. The additional tubing is formed with a flange in contact with the open end of the sealing member and the protective tubing.

There is also a detection section for detecting the leakage of molten metal between the protective tube and the tapered hole, which is located near the sealing member and connected to the control section located outside the furnace by lead wires.

In addition, the detection unit is an electric resistance type or a heat resistance type.

In the refractory formed in the furnace, a partition wall partitioning the space is formed, and the partition wall is formed to keep the molten metal in the partition chamber. The partition wall may be removed. For example, the partition wall forms a first compartment, a second compartment for pouring molten metal, and a third compartment for detecting the temperature of the molten metal in the refractory between the first and second compartments. The first and second compartments are connected to the third compartment via a hole formed in the lower portion of the dividing wall.

Small covers for covering the first compartment are separated from the main cover. Since only this small lid can be opened, the heat radiation of the molten metal can be minimized. The cover includes a ceramic fiber layer. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show a first embodiment of an underheater furnace for maintaining an aluminum alloy at a high temperature of 680-720 ° C. after reduction, slug removal and other treatments for molten aluminum prior to use in die casting. It is shown.

The furnace consists of a refractory material (3) made of an integral or solid castable material to retain the molten aluminum alloy, an insulating layer (10) made of ceramic fiber material and a furnace outer wall (4) of known metals. have.

The heat insulating layer 10 is fixed to the outside of the refractory 3 to thermally cover the refractory 3.

The heat insulation layer 10 is comprised from the several layer which consists of ceramic fibers like FIG. Aluminum foil can be inserted between the thermal insulation layers. 1a indicates the surface of the molten aluminum 1 contained in the refractory 3.

The molten aluminum 1 is heated by means of a heating means H with a protective tube 2 and a heater 5 embedded in the protective tube 2.

The protective tube 2 protects the heater 5 from the molten aluminum alloy 1 in the refractory 3.

The heater 5 has a heating burr made of silicon carbide. The tapered holes 9 are formed below the refractory 3.

The tapered holes 9 are provided with tapered spirals 9a while widening outward.

The sealing member 12 is filled between the tapered hole 9 and the protective tube 2 so that the protective tube 2 is fixed to the refractory 3.

The protective tube 2 has an open end 2a and a closed end 2b. The refractory 3 is provided with the 1st support part below and the 2nd support part 11 on the opposite side.

The first support part comprises a tapered hole 9, and the second support part 11 is a stepped part formed in a corner between the side wall and the bottom wall of the refractory 3. The opening end 2a of the protective tube 2 is filled with the sealing member 12 in the tapered hole 9 of the first support part and fixed.

The closed end 2b of the protective tube 2 is freely supported by the second support 11 opposite to the first support. The protective tubing 2 extends close to the bottom wall between both side walls of the refractory 3.

Since the blocked end 2b of the protective tube 2 is not fixed to the first support 11 of the staircase type, the blocked end 2b of the protective tube 2 does not move downward. The second support 11 can be moved without being moved.

The detection part 6 which detects the leak of the molten aluminum alloy 1 is formed in the open end part 2a side of the protection tube 2, The detection part 6 is located near the sealing member 12, have.

It is preferable that the detection part 6 faces toward the outer end of the circularly tapered hole 9. The detection part 6 is connected with the lead wire 6a to the adjustment apparatus (not shown) located in the outer side of a furnace.

As shown in FIG. 2, the open end 2a of the protective tubing 2 extends to the outer circumferential surface of the side wall of the refractory 3, and extends to the furnace outer wall 4 through the thermal insulation layer 10. The open end 2a of the protective tube 2 is coupled to one end of the additional tube 8 made of a ceramic fiber material having heat insulation. The additional tube 8 has a flange 8a in contact with the sealing member 12 and the open end 2a of the protective tube 2.

In addition, the heater 5 is connected to the control unit (not shown) through the connecting portion 13, and the filler is positioned between the protective tube 2 and the heater 5 as described above.

3 and 4 show a second embodiment of the present invention in which the gas burner heater 5 'is used as the heating means H. As shown in FIG. Except for the heating means H, the second embodiment is the same as the first embodiment, the gas burner heater 5 'is a burner body 5a located at the inlet of the protective tube 2'. Equipped with. The end of the burner body 5a is located near the side wall of the refractory 3.

A pipe 5b with a number of small through holes at any number of points is located in the protective tube 2 'and extends to its blocked end 2b.

The heated hot gas at the end of the burner body 5a enters the circular gap between the protective tube 2 'and the pipe 5b through the small holes of the pipe 5b.

Then, the hot gas flows to the right and is then discharged through the outlet 5c.

An example of a gas burner heater is described in Japanese Patent Publication No. 57-40406.

In the second embodiment, the open end 2a of the protective tube 2 'extends through the heat insulating layer 10, so that an additional tube made of heat insulating material may be shortened or removed.

In the first and second embodiments, the dividing wall 18 is formed in the refractory 3 as shown in the first, third and sixth degrees. The partition wall 18 includes a first compartment 19, a second compartment 20 for pouring molten metal into the refractory 3, and a third compartment for detecting the temperature and level of the molten metal in the refractory 3. 21).

As shown in FIG. 6, the first and third compartments 19 and 21 are connected through two holes 25 and 26 formed in the lower portion of the dividing wall 18. The second and third compartments 20 and 21 are connected through holes 27 formed in the lower part of the dividing wall 18.

In the illustrated embodiment, the partition wall 18 is formed in a "T" shape, but the present invention is not limited to this form.

The three protective tubes 2 are horizontally arranged in parallel to each other and penetrate through the angled holes 25, 26, and 27.

And as shown in FIG. 5, the small cover 22 which blocks only the 1st compartment 19 is isolate | separated from the main cover 23. As shown in FIG.

The lids 22 and 23 are provided with the ceramic fiber layer 24 as shown in FIG.

The handle 29 of FIG. 5 is fixed to the upper portion of the small lid 22. Only the small lid 22 can be opened to grab the handle 29 and to disperse the molten metal into the first compartment 19. The small lid 22 can also be a slide type. The sensor part 16 of FIG. 1 and FIG. 3 is attached to the main cover 23 on the 3rd compartment 21 in order to detect the arbitrary upper and lower limits of the surface level and temperature of molten metal in the refractory 3. The sensor unit 16 has a protective tube 16a made of silicon liquefied and clogged at its lower end. As described above, the sensor unit 16 may be connected to an adjusting unit (not shown) formed outside the furnace to which the detecting unit 6 for detecting leakage of molten metal is connected.

The injection part 15 is being fixed to the main cover 23 of the upper part of the 2nd compartment 20 as shown in FIG. The inner wall 15a of the injection part 15 is tapered. The pipe-like portion 15b is made of ceramic fiber material and has a metal net formed therein for reinforcement purposes. If the inner diameter of the pipe-like portion 15b is small, large impurities may be caught at the top thereof.

Reference numeral 17 denotes a plurality of ceramic tubing that supports the refractory 3.

Although only furnaces with melts have been described, the invention can be applied to furnaces for melting metals of low melting point.

Claims (7)

In a heater-type furnace having a refractory material (3) capable of keeping the molten metal warm and a heat insulating layer (10) made of ceramic fiber material on the outside of the refractory material (3), the end portion (2a) opened to enclose the heater (5). Protection tube 2 having a closed end 2b, and a refractory tube 3 partitioned into first, second and third compartments 19, 20 and 21. A sealing member 12 formed between the tapered hole 9 and the protective tube 2 to fix the opened end portion 2a side of the < RTI ID = 0.0 >), < / RTI > and the closed end of the protective tube 2 2b) is composed of a second support portion (11) for freely moving. The underheater furnace according to claim 1, wherein a tapered spiral (9a) is formed in the tapered hole (9). The underheater furnace according to claim 1, wherein partition walls (18) defining partition chambers (19), (20), and (21) for partitioning the molten metal in the refractory (3) are formed. 2. The underheater furnace according to claim 1, wherein a detector (6) is formed near the sealing member (12) to detect the leakage of molten metal between the protective tube (2) and the tapered hole (9). 2. The open end 2a of the protective tube 2 is coupled to one end of the additional tube 8, which ends at the outer surface of the refractory 3 and extends through the thermal insulation layer 10. Under heater type furnace. 6. The additional tubing (8) according to claim 5, wherein the additional tubing (8) has an understage with a flange (8a) at one end of each other to contact the sealing end (12) and the open end (2a) of the protective tubing (2). Heater type furnace. 2. The underheater furnace according to claim 1, wherein each of the plurality of protective tubing (2) surrounding the heater (5) is arranged horizontally parallel to each other.