JPH0886432A - Molten metal heating device - Google Patents

Abstract

PURPOSE: To provide a device capable of performing a high efficient and energy- saving heating of molten metal stored in a molten metal tank. CONSTITUTION: In a molten metal heating device 4 in which a ceramic cylindrical outer cylinder 16 having a bottom therein is suspended vertically in a molten metal tank 1 of molten metal (m), a combustion cylinder 20 for use in blowing out combustion gas toward an inner bottom part of the outer cylinder 16 is suspended vertically at the center of the outer cylinder 16 and combustion gas blown out of the combustion cylinder 20 is reversed at the inner bottom part of the outer cylinder 16 and discharged out upwardly, a cylinder having a larger diameter than that of the combustion cylinder 20 is placed adjacent to a blowing port for the combustion gas, the larger cylinder is vertically installed within the outer cylinder 16 and then the combustion gas is recirculated within the cylinder with a back pressure of combustion flame blown out of the combustion cylinder 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for heating molten metal in a bath.

[0002]

2. Description of the Related Art A bottomed cylinder (hereinafter referred to as an outer cylinder) is hung from above in molten metal stored in a hot water tank, and a combustion cylinder (burner) for blowing out combustion gas toward the bottom in the outer cylinder. )
A heating device which is provided with an external cylinder wall to heat the molten metal by transferring heat is known from, for example, JP-A-61-49986 and JP-A-1-287228. Since some types of heating devices can transfer the combustion heat to the molten metal with relatively little waste, there is an energy saving advantage.

[0003]

However, the conventional heating device has a problem that the combustion gas is discharged before the heat is sufficiently transferred to the outer cylinder wall because the residence time of the combustion gas in the outer cylinder is short. Therefore, the effective heating capacity of the conventional heating device of this type is 6 × 10 ⁴ kc per one at maximum.
Al / h, and in a furnace that requires heating capacity, the number of installations had to be increased, but if this was done, the surface area of the furnace body would increase, heat loss would increase, and furnace construction costs would also increase. There is a problem.

Further, in order to effectively utilize the sensible heat of the combustion gas discharged from the outer cylinder, in the invention of the above-mentioned Japanese Patent Laid-Open No. 1-287228, the combustion gas is discharged to the space below the heat insulating lid provided in the hot water tank. However, there is a problem in that when the temperature of the combustion gas is much higher than the temperature of the molten metal, a large amount of oxide (slag) of the metal is generated over time.

Therefore, the present invention is intended to solve the above problems and to provide a molten metal large capacity heating device which can be safely used for the purpose of saving space and energy.

[0006]

To this end, according to the present invention, a bottomed cylindrical outer cylinder made of ceramics is hung in a molten metal bath and burned at the center of the outer cylinder toward the inner bottom of the outer cylinder. In a molten metal heating device in which a combustion cylinder that blows out gas hangs down, and the combustion gas blown out from the combustion cylinder is inverted at the bottom of the outer cylinder and discharged upward, a cylinder having a diameter larger than that of the combustion cylinder. The body is vertically disposed in the outer cylinder with its combustion gas outlet facing the center, and the combustion gas is recirculated in the cylinder by the back pressure of the combustion flame blown out from the combustion cylinder. To do.

Further, according to the present invention, a bottomed cylindrical outer cylinder made of ceramics is blown into a molten metal bath so that the combustion gas blown out from the downward combustion cylinder is reversed at the inner bottom of the outer cylinder and discharged upward. In the molten metal heating device described above, an annular baffle plate is arranged on the inner circumference of the outer cylinder.

Further, the present invention is characterized in that, in the above-mentioned molten metal heating apparatus, a flame dispersion member formed by vertically arranging a plurality of partition plates in the inner cylinder bottom is provided.

Further, according to the present invention, a flue which communicates with a material-to-be-dissolved material charging chamber adjacent to a heat insulating lid provided in a molten metal bath is formed, and a ceramic hole is provided through a mounting hole formed in the heat insulating lid. A bottom cylinder-shaped outer cylinder is hung in the hot water tank, a combustion cylinder that blows out combustion gas toward the inner bottom of the outer cylinder is hung at the center of the outer cylinder, and the combustion gas blown out from the combustion cylinder is It is characterized in that it is turned upside down on the inner bottom of the outer cylinder and guided to the melted material feeding chamber through the flue.

Further, according to the present invention, a ceramic bottomed cylindrical outer cylinder is blown into a molten metal hot water tank from a hanging combustion cylinder so that the combustion gas is inverted at the inner bottom of the outer cylinder and discharged upward. In the molten metal heating device described above, a pressure detector is provided in the air supply pipe that supplies combustion air to the combustion cylinder, and a gas cutoff valve is provided in the gas supply pipe that supplies combustion gas to the combustion cylinder. It is characterized in that the gas cutoff valve is closed by the abnormal low pressure signal and the abnormal high pressure signal.

[0011]

By arranging the cylindrical body and the baffle plate, the residence time of the combustion gas in the outer cylinder becomes longer and the heat dissipation and heat transfer properties are improved. Further, by providing the flame dispersion member, the combustion gas blown toward the inner bottom of the outer cylinder is uniformly inverted to the surroundings so that the bottom of the outer cylinder is uniformly heated.

Further, the sensible heat of the combustion gas is preheated to the material to be melted by guiding the combustion gas discharged from the outer cylinder to the material to be melted chamber through the flue formed in the heat insulating lid. Make effective use of. Also, by providing a pressure detector, a shutoff valve, etc., safety is ensured against cracking of the outer cylinder during operation or combustion.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view of this molten metal heating apparatus, and FIG. 2 is a vertical cross-sectional view of the main part thereof, in which 1 is a hot water tank for storing the molten metal m, 2 is adjacent to the hot water tank and a partition wall 2a. The material-to-be-dissolved chamber 3 formed as described above is a heat-insulating lid that covers the bath 1. The heat-insulating lid 3 has a flue 3a communicating with the material-to-be-melted chamber 2 and is circular. The mounting hole 3b is opened.

Reference numeral 4 denotes a molten metal heating device attached to the mounting hole 3b. The molten metal heating device 4 has a flange 5a,
The cylindrical base body 5 having the 5b formed therein is vertically supported in the mounting hole 3b by supporting the flange 5a on the upper surface of the heat insulating lid 3. The cylinder 6 is formed in the base body 5. Reference numeral 6a is a supply air connecting pipe portion communicating with the supply cylinder 6.

A lid 7 is attached to the center of the upper portion of the supply cylinder 6, and a rod-shaped ignition device 8 having an ignition portion 8a at its tip is hung from the lid. Reference numeral 9 denotes a gas supply cylinder that hangs down from the center of the supply cylinder 6. Reference numeral 10 denotes a gas supply connecting pipe portion formed on the lid body 7 so as to communicate with the gas supply cylinder 9.

As shown in FIG. 3, the flange 5b at the lower end of the base 5 is provided with a plurality of stop holes 12a, and the pins 12 are integrally formed on the upper edge of the annular connecting body 15 so as to project therefrom. Is inserted into each stop hole 12a and the flange 5b of each pin 12 is inserted.
The wedges 13 are inserted into the lateral holes provided in the portion projecting upward, and the wedges 13 are supported on the upper surface of the flange 5b to fix the annular connecting body 15 to the base 5. Reference numeral 14 is a small cylinder provided on one side of the base body 5 for discharging combustion gas.

Reference numeral 16 denotes a bottomed cylindrical outer cylinder 16 made of ceramics which is excellent in heat resistance, and the outer cylinder 16 is connected to the annular coupling body 1.
5 is made to engage with the molten metal m in the hot water tank 1 so that the molten metal m hangs down. The annular connecting body 15 is engaged with the enlarged diameter portion 16a formed on the upper edge of the outer cylinder 16. Further, 17 is a ceramics wool that closes the gap of the connecting portion.

Reference numeral 20 is a combustion cylinder that hangs down from the center of the supply cylinder 6 into the outer cylinder 16. In the combustion cylinder 20, the supply gas cylinder 9 hangs and a burner member 24 is installed at the lower end of the supply gas cylinder 9. Has been done. A large number of combustion gas outlets 24a are formed in the burner member 24.

Further, as shown in FIG. 1, the air supply connecting pipe portion 6
A pressure detector 27a for detecting an abnormal low pressure signal and a pressure detector 2 for detecting an abnormal high pressure signal are provided in the air supply pipe 26 communicating with a.
7b is provided. The supply gas pipe 30 communicating with the supply gas connection pipe portion 10 is provided with a shutoff valve 32.

Reference numeral 40 denotes a molded article made of ceramics according to the present invention, which is provided on the inner bottom portion of the outer cylinder 16 for improving efficiency. The molded body 40, as shown in FIG.
A flame dispersion member 42 formed by vertically arranging a plurality of partition plates 41 in a radial shape (a cross shape in a plane), a cylindrical body 43 formed perpendicularly to the upper center of the flame dispersion member 42, and an upper outer portion of the flame dispersion member 42. It is composed of an annular baffle plate 44 formed on the peripheral edge. The diameter of the cylindrical body 43 is made larger than that of the combustion cylinder 20, and the outer cylinder 1
6 When placed at the inner bottom, the combustion gas outlet 21 of the combustion cylinder 20 faces the center thereof, and the baffle plate 44 and the outer cylinder 1
It is located almost in contact with the inner peripheral surface of 6.

However, in this heating device, the air outlet 24a
And a mixed gas of combustion gas and fuel gas ejected from 24b are ignited in the ignition portion 8a, a downward combustion flame is formed in the combustion cylinder 20, and the combustion gas is blown toward the inner bottom of the outer cylinder 16. Flip upwards at the bottom. At this time, the combustion gas is partitioned by the flame dispersion member 42, is evenly distributed around the periphery, and is turned upward along the inner peripheral surface of the outer cylinder 16. Then, because of the baffle plate 44, it goes up slightly upward and rises.
Further, since the combustion flame vigorously blows out from the combustion gas outlet 21 into the cylindrical body 43, the combustion gas in the outer cylinder 16 is sucked into the cylindrical body 43 due to its back pressure and burns as shown by the arrow in the figure. Gas recirculates.

As described above, since the cylindrical body 43 is provided in the outer cylinder 16, the combustion gas is recirculated and the baffle plate 4 is used.
Since the combustion gas bypasses the baffle plate 44 in the outer cylinder 16 and rises due to the provision of No. 4, the residence time of the combustion gas in the outer cylinder 16 becomes long. Therefore, heat transfer through the wall of the outer cylinder 16 is improved, and the molten metal m can be efficiently heated.

Further, the combustion gas generated in the outer cylinder 16 reaches the melted material charging chamber 2 from the small cylinder 14 through the flue 3a, and preheats the melted material in the melted material charging chamber 2. It is effectively used for.

If a crack enters the outer cylinder 16 during operation and the molten metal m enters and the combustion cylinder 20 is blocked, the air pressure in the air supply pipe 26 becomes abnormally low or abnormally high. The abnormal pressure is detected by the detector 27a or 27b, and the shutoff valve 32 is immediately shut off by the signal thereof, so that dangerous raw gas is prevented from blowing out and the safe operation can be performed. Although the pressure detectors 27a and 27b are provided in the air supply pipe 26 in this embodiment, they may be provided in the gas supply pipe 30 to detect the abnormal pressure.

[0025]

As described above, in the molten metal heating apparatus according to the present invention, by disposing the cylindrical body and the baffle plate in the outer cylinder,
The residence time of the combustion gas in the outer cylinder becomes longer, and the heat dissipation and heat transfer properties are greatly improved. Further, by providing the flame dispersion member, the combustion gas blown toward the bottom of the outer cylinder is evenly inverted to the surroundings so that the bottom of the outer cylinder is uniformly heated, and the thermal efficiency is greatly improved. Since the heating capacity is also high, there are significant effects such as the cost of furnace construction can be reduced.

Further, the sensible heat of the combustion gas is preheated to the material to be melted by guiding the combustion gas discharged from the outer cylinder to the material to be melted chamber through the flue formed in the heat insulating lid. It is effective for energy saving. Further, when the outer cylinder is broken, the supply of fuel gas and the like can be immediately shut off to maintain safety during operation.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a hot water tank showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the main part of FIG.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is a perspective view of a ceramic molded body.

[Explanation of symbols]

 m Molten metal 1 Hot water tank 2 Melting material charging chamber 2a Partition wall 3 Insulation lid 3a Flue 4 Molten metal heating device 5 Base body 6 Supply cylinder 14 Small cylinder 15 Annular connection body 16 Outer cylinder 20 Combustion cylinder 21 Air outlet 24 Burner member 26 Air supply pipe 27a, 27b Pressure detector 30 Gas supply pipe 32 Shut-off valve 40 Molded body 41 Partition plate 42 Flame dispersion member 43 Cylindrical body 44 Baffle plate

Claims (5)

[Claims] 1. A bottomed cylindrical outer cylinder made of ceramics is hung in a molten metal bath, and a combustion cylinder for blowing out combustion gas toward the inner bottom of the outer cylinder is hung at the center of the outer cylinder. In the molten metal heating device in which the combustion gas blown out from the combustion tube is inverted at the bottom of the outer cylinder and discharged upward, a cylindrical body having a diameter larger than that of the combustion tube is centered around the combustion gas outlet. A molten metal heating device, characterized in that it is vertically installed in an outer cylinder so that the combustion gas is recirculated in the cylinder by the back pressure of the combustion flame blown out from the combustion cylinder. 2. A bottomed cylindrical outer cylinder made of ceramics is hung in a molten metal bath, and a combustion cylinder for blowing out combustion gas toward the inner bottom of the outer cylinder is hung at the center of the outer cylinder. In a molten metal heating device in which the combustion gas blown out from the combustion cylinder is inverted at the inner bottom portion of the outer cylinder and discharged upward, an annular baffle plate is arranged on the inner periphery of the outer cylinder. A molten metal heating device characterized by: 3. The molten metal heating apparatus according to claim 1, further comprising a flame dispersion member formed by vertically arranging a plurality of partition plates on a bottom portion of the outer cylinder. 4. A heat insulating lid provided in a molten metal bath,
A flue that communicates with the adjacent material-to-be-melted material forming chamber is formed, and a bottomed cylindrical outer cylinder made of ceramics is hung in the hot water tank through a mounting hole formed in the heat insulating lid, and the center of the outer cylinder is formed. Hanging down the combustion cylinder that blows out the combustion gas toward the bottom of the outer cylinder,
A molten metal heating device characterized in that the combustion gas blown out from the combustion cylinder is inverted at the inner bottom of the outer cylinder and guided to the melted material charging chamber through the flue. 5. A bottomed cylindrical outer cylinder made of ceramics is hung in a molten metal bath, and a combustion cylinder for blowing out combustion gas toward the inner bottom of the outer cylinder is hung at the center of the outer cylinder. In the molten metal heating device in which the combustion gas blown out from the combustion cylinder is inverted at the inner bottom of the outer cylinder and discharged upward, a pressure detector is provided in the air supply pipe for supplying combustion air to the combustion cylinder. At the same time, a gas cutoff valve is provided in a supply gas pipe for supplying combustion gas to a combustion cylinder, and the gas cutoff valve is closed by an abnormal low pressure signal and an abnormal high pressure signal of the pressure detector. Heating device.