JP2002147970A - Preheating device for ingot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that, in a conventional electric heater type preheating device, since heating capacity is low and a temperature increase speed is not so fast, when heating capacity is increased, a heater is increased in size and as a result, the whole of a device is increased in size; a temperature increasing time is needed for a long time, an ingot is heated to temperature higher than necessary temperature, and a trouble is apt to occurs; and since most of a conveyance line is covered by an electric heater, a charge opening for an ingot is normally limited to one spot and it takes a long time to effect charging. SOLUTION: The preheating device for the ingot is proposed that a preheat chamber surrounded by a wall is formed at a part of a conveyance line situated at a part of a holding part 8 for the ingot 7, and constitution is such that the ingot is conveyed through the preheating chamber, and a surface combustion burner 14 is situated in a preheating chamber and in the opposite position of the ingot conveyed through the preheating chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preheating an ingot such as light metal.

[0002]

2. Description of the Related Art As a conventional preheating apparatus for preheating an ingot such as light metal prior to melting or the like, there is an electric heater type as shown in FIGS. 5 and 6, for example. In the figure, reference numeral a denotes a cylindrical rotating body that is rotated by a motor b, and an ingot case d that holds a number of ingots c in a vertical direction is provided around the cylindrical rotating body a. The cylindrical rotating body a is rotatably installed in a preheating device main body f having a cylindrical side wall e, and is configured to convey the ingot c by rotation. An electric heater g is installed on the inner periphery of the cylindrical side wall e, and a space between the cylindrical rotating body a and the electric heater g constitutes a preheating chamber h. On the other hand, an inlet i for an ingot c is provided at one location on the cylindrical side wall e, and an outlet l having a door device k is provided on an upper wall j at a position farthest from the inlet i in the transport direction. ing. Above the outlet 1, there is provided an ingot transfer device m for holding the upper part of the ingot c, extracting it from the ingot case d, and transferring it to a predetermined position. Note that reference numeral n is a door of the inlet i.

In the above arrangement, the ingot c is pulled out of the ingot case d by the ingot conveying device m and taken out of the outlet 1, and then the cylindrical rotating body a is rotated by a unit angle to put the empty ingot case d into the inlet. The ingot c is held in the empty ingot case d from the charging port i at the position i. After the elapse of the predetermined time and the temperature rise, the ingot c is taken out from the outlet 1 and the ingot c is put in from the inlet i.

As another example of the conventional preheating apparatus, there is a method of preheating an ingot by supplying combustion exhaust gas of a combustion burner for heating a melting and holding furnace to a preheating chamber.

[0005]

First, the former electric heater type preheating device has the following problems. a. Because the heating capacity is low and the heating rate is not so fast,
If you try to increase the heating capacity, the heater part becomes large,
As a result, the entire apparatus becomes large. b. a. For the same reason as described above, a long time is required to raise the temperature, and the ingot is likely to be heated more than necessary and oxidized. c. Since most of the transfer line is covered with the electric heater, the inlet for the ingot is usually limited to one place. Therefore, when the ingot is manually charged, a plurality of ingots cannot be simultaneously performed, but must be performed one by one at a constant interval, and the work is troublesome. Also, the latter method using combustion exhaust gas has the above-mentioned problems a and b similarly to the former method. An object of the present invention is to solve such a problem.

[0006]

According to the present invention, in order to solve the above-mentioned problems, a preheating chamber surrounded by a wall is formed in a part of a transfer line provided with a holding portion for the ingot, and the ingot is preheated. The present invention proposes an ingot preheating device in which a surface combustion burner is installed at a position facing an ingot to be conveyed in a preheating chamber.

In the present invention, in the above configuration, the transport line may be configured to transport the ingot in a vertical direction by the holding unit, or may be configured to transport the ingot in the horizontal direction by the holding unit. In some cases, a configuration in which the sheet is conveyed while being held in an oblique direction can be adopted.

Further, according to the present invention, in the above configuration,
In the transport line, a heat shield plate may be provided between each holding portion of the ingot, and each heat shield plate may be configured to form a part of a wall of the preheating chamber at an entrance of the preheating chamber.

Further, according to the present invention, in the above configuration,
The entrance and exit of the preheating chamber may be provided with a flexible heat-resistant partition.

Further, according to the present invention, in the above configuration, the preheating chamber has a configuration capable of accommodating a plurality of ingots, a surface combustion burner is provided at an outlet side of the ingot, and an exhaust portion is provided at an inlet side of the ingot. It can be configured.

Further, in the present invention, the surface material of the surface combustion burner in the above configuration may be a heat-resistant metal fiber processed into a plate shape or a knitted shape.

According to the present invention, since a very short flame is formed on the surface of the surface combustion burner, the flame can directly and efficiently heat the ingot by radiation and convection without touching the ingot. it can. Therefore, since the ingot can be heated in a short time, generation of oxide on the surface of the ingot can be reduced.

The heat shield plate provided on the transfer line forms a part of the wall at the entrance and exit of the preheating chamber, and the flexible heat-resistant partition is provided at the entrance and exit of the preheating chamber. Heat release can be minimized.

The preheating chamber has a structure capable of accommodating a plurality of ingots, a surface combustion burner is provided on the outlet side of the ingot, and an exhaust portion is provided on the inlet side, so that the outlet facing the surface combustion burner is provided. The combustion exhaust gas after directly heating the ingot on the side can preheat the ingot closer to the inlet than the ingot.

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment of a preheating apparatus according to the present invention. FIG. 1 is a schematic cross-sectional view, and FIG. 2 is a schematic vertical cross-sectional view.

In FIG. 1, reference numeral 1 denotes a cylindrical rotary member which is driven to rotate by a motor 2, and this cylindrical rotary member 1 is rotatably supported on a gantry 4 by an auxiliary roller 3.
A rotation drive mechanism such as a reduction gear 5 and a clutch mechanism 6 is provided between the rotation axis of the motor 2 and the rotation axis of the cylindrical rotary body 1.

A plurality of ingot cases 8 for holding the ingot 7 in the vertical direction are provided around the cylindrical rotating body 1 at equal intervals to form a transport line for the ingot 7. A heat shield plate 9 is provided between each adjacent ingot case 8.
Is installed.

Reference numeral 10 denotes a preheating chamber.
Is constituted by an arc-shaped tunnel having an inlet-side opening 12 and an outlet-side opening 13 surrounded by the furnace wall 11 and the wall of the cylindrical rotating body 1. The openings of the inlet side opening 12 and the outlet side opening 13 are narrower than the inside of the preheating chamber 10 and slightly larger than the heat shield plate 9.

As shown in FIG. 1, the preheating chamber 10 has three ingot cases 8 and 3 inside, with the heat shield plates 9 being positioned at the inlet side opening 12 and the outlet side opening 13 at the same time.
Therefore, the length is configured such that the three ingots 7 are located.

As described above, the interior of the preheating chamber 10 is wider than the inlet-side opening 12 and the outlet-side opening 13.
A surface combustion burner 14 is provided on a side wall portion of the furnace wall 11. In this embodiment, the surface combustion burner 14 is installed near the outlet opening 13, and the exhaust part connected to the exhaust flue 15 is installed near the inlet opening 12.

As the surface material of the surface burning burner 14, any suitable material can be used. For example, a material obtained by processing a special heat-resistant metal fiber into a plate shape or a knitted shape can be used.

In the above configuration, the cylindrical rotary body 1 is rotationally driven by the rotary drive mechanism, and the heat shield plates 9 are simultaneously positioned at the inlet opening 12 and the outlet opening 13 as shown in FIG. In this state, the operation is stopped and preheating is performed.
That is, in this state, each heat shield plate 9 closes the inlet-side opening 12 and the outlet-side opening 13 so that the release of heat from the preheating chamber 10 can be minimized.

In the state shown in FIG. 1, the ingot 7 held by the ingot case 8 located closest to the outlet-side opening 13 in the preheating chamber 10 is formed on the surface of the opposed surface combustion burner 14. The short flames are directly heated by radiation and convection without touching the flames.
Therefore, the ingot 7 is heated in a short time, and the generation of oxides on the surface can be reduced.

The combustion exhaust gas that has heated the ingot 7 closest to the outlet opening 13 in this way flows in the preheating chamber 10 toward the inlet opening 12, and the other ingot 7 located in the preheating chamber 10 After preheating, the air is exhausted from the exhaust part through the exhaust flue 15.

After a lapse of a predetermined time in the preheating state shown in FIG. 1, the cylindrical rotary body 1 is rotationally driven by the rotary drive mechanism so that the next heat shield plate 9 corresponds to the inlet opening 12 and the outlet opening 13. The next ingot 7
Is in the same state as in FIG. 1, and in this state, preheating is performed in the same manner as described above.

The ingot 7 which has reached the outside of the preheating chamber 10 through the outlet opening 13 due to the rotation of the cylindrical rotary body 1.
Can be extracted upward from the ingot case 8 by a suitable transporting means, for example, a transporting means as shown in FIG. 5, and transported to a subsequent processing means.

On the other hand, the ingot 7 before the preheating is mounted on the empty ingot case 8 from which the preheated ingot 7 has been extracted, and is used for the subsequent preheating. At this time, in this embodiment, since the ingot can be attached to the ingot case 8 provided on the cylindrical rotating body 1 at any time except for the preheating chamber 10, as in the related art,
It is not necessary to mount the ingot every time the preheated ingot 7 is extracted, and the ingots can be collectively mounted on a plurality of ingot cases 8 at appropriate times.

FIGS. 3 and 4 show a second embodiment of the preheating apparatus according to the present invention. FIG. 1 is a schematic longitudinal sectional view, and FIG. 2 is a plan view. In the figure, reference numerals 16, 1
Reference numerals 7, 18, and 19 denote first, second, third, and fourth conveyors, respectively, which constitute a transport line for the ingot 7. First,
The second conveyors 16 and 18 are provided with driving motors 20 and 2 respectively.
1. A belt conveyor driven by 1 and provided with a partitioning / stopper 22 at predetermined intervals of these belts,
The space between these stoppers 22 is
It is constituted as. On the other hand, the second and fourth conveyors 1
Rollers 7 and 19 transport the ingot 7 by its own weight, and these conveyors 17 and 19 may be chute for lowering their own weight instead of the rollers.

The third conveyor 18 constitutes a horizontal transport path 23 on the upper side, and this transport path 23 is surrounded by a furnace wall 24 and has a tunnel provided with an inlet opening 25 and an outlet opening 26. The preheating chamber 27 has a shape of a circle. The inlet opening 25 and outlet opening 26 of the preheating chamber 27
Heat-resistant curtain 28, 2 as a heat-resistant partition having flexibility
9 are installed.

The preheating chamber 27 has respective heat-resistant curtains 28,
In the state where the partition / stopper 22 of the third conveyor 18 corresponds to the lower portion of
0, and thus the length at which the three ingots 7 are located. The transport path 2 that moves inside the preheating chamber 27 in this way
It goes without saying that the third conveyor 18 having 3 is made of a heat-resistant material.

In the preheating chamber 27, a surface combustion burner 31 is installed on the upper wall portion. In this embodiment, the surface combustion burner 31 is installed near the outlet opening 26 and connected to the exhaust flue 32. The exhaust unit is provided near the inlet opening 25.

As the surface material of the surface combustion burner 31 of this embodiment, any suitable material can be used in the same manner as in the above-mentioned embodiment. A knitted metal fiber can be used.

In the above configuration, the ingot 7 before preheating is lifted by being held by the holding portion 30 of the first conveyor 16 driven by the driving motor 20, passes through the second conveyor 17, and moves up to the third conveyor. After being transferred onto the holding section 30 and preheated through the preheating chamber 27, it is transferred onto the fourth conveyor 19 and transported to a predetermined place.

In the state of FIG. 3, the ingot 7 located near the outlet opening 26 in the preheating chamber 27 is touched by a very short flame formed on the surface of the opposed surface combustion burner 31. Instead, the ingot 7 is directly heated by radiation and convection, so that the ingot 7 is heated in a short time,
Oxide generation on the surface can be reduced.

The combustion exhaust gas which has heated the ingot 7 near the outlet opening 13 as described above flows in the preheating chamber 27 in the direction of the inlet opening 25, and at this time, is located near the inlet opening 25 in the preheating chamber 27. After the other ingot 7 is preheated, it is exhausted from the exhaust part through the exhaust flue 32.

At this time, the combustion exhaust gas in the preheating chamber 27 is prevented from flowing out of the inlet-side opening 12 and the outlet-side opening 13 by the heat-resistant curtains 28 and 29 and the partition / stopper 22, thereby minimizing heat release. Can be suppressed.

In this embodiment, the third conveyor 18
As in the first embodiment, the ingot 7 can be intermittently conveyed and stopped so as to be in the state of FIG. 3 for each movement, as in the first embodiment. Can also be configured.

In the above embodiment, the transport line is configured to hold and transport the ingot in the vertical direction by the holding unit, or to transport the ingot in the horizontal direction by the holding unit. In some cases, a configuration in which the sheet is conveyed while being held in an oblique direction can be adopted.

In the above embodiment, the surface combustion burner is installed near the outlet opening of the preheating chamber and the exhaust part is arranged near the inlet opening. However, the arrangement of the surface combustion burner and the exhaust part is as follows. In addition, it can be configured at an appropriate place in the preheating chamber.

[0040]

As described above, the present invention has the following effects. a. In the preheating chamber, a very short flame is formed on the surface of the surface combustion burner, so that the flame can directly and efficiently heat the ingot by radiation and convection without touching the ingot. b. For the reason a, since the ingot can be heated in a short time, the generation of oxides on the surface of the ingot can be reduced, and when the ingot is needed, it can be heated and supplied in a short time. it can. c. For the reason a, the burner and the ingot can be installed close to each other, so that the preheating chamber can be made compact. d. Since the preheating chamber is formed only in a part of the transfer line, the restriction on the place where the ingot is put into the transfer line is relaxed, and it becomes possible to put a plurality of ingots at the same time. . e. The preheating chamber has a configuration capable of accommodating a plurality of ingots, a surface combustion burner is installed on the outlet side of the ingot, and an exhaust portion is provided on the inlet side, so that the ingot on the outlet side facing the surface combustion burner. The ingot on the inlet side of the ingot can be preheated by the combustion exhaust gas after directly heating the ingot. f. Heat is released from the preheating chamber by the configuration in which the heat shield plate provided on the transfer line forms a part of the wall at the entrance and exit of the preheating chamber and the configuration in which a flexible heat-resistant partition is provided at the entrance and exit of the preheating chamber. Can be minimized.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a first embodiment of the present invention.

FIG. 2 is a schematic longitudinal sectional view for explaining the first embodiment of the present invention.

FIG. 3 is a schematic longitudinal sectional view illustrating a second embodiment of the present invention.

FIG. 4 is a plan view illustrating a second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view illustrating an example of a conventional preheating device.

FIG. 6 is a cross-sectional view illustrating an example of a conventional preheating device.

[Explanation of symbols]

Reference Signs List 1 cylindrical rotating body 2 motor 3 auxiliary roller 4 gantry 5 reduction gear 6 clutch mechanism 7 ingot 8 ingot case 9 heat shield plate 10 preheating chamber 11 wall 12 inlet side opening 13 outlet side opening 14 surface combustion burner 15 exhaust flue 16th 1 Conveyor (Belt Conveyor) 17 2nd Conveyor (Roller) 18 3rd Conveyor (Belt Conveyor) 19 4th Conveyor (Roller) 20, 21 Driving Motor 22 Partition / Stopper 23 Horizontal Transfer Path 24 Furnace Wall 25 Inlet-side opening 26 Outlet-side opening 27 Preheating chamber 28, 29 Heat-resistant curtain 30 Holder 31 Surface combustion burner 32 Exhaust flue

Claims (8)

[Claims] A preheating chamber surrounded by a wall is formed in a part of a transfer line provided with an ingot holding portion, and the ingot is transported through the preheating chamber. Ingot preheating device characterized by surface burners installed at opposing positions 2. The ingot preheating apparatus according to claim 1, wherein the transport line is configured to transport the ingot in a vertical direction by a holding unit. 3. A preheating apparatus for an ingot, wherein the conveying line is configured to convey the ingot by holding the ingot in a lateral direction by a holding section. 4. A transfer line, wherein a heat shield plate is provided between each holding portion of the ingot, and each heat shield plate is configured to form a part of a wall of the preheating chamber at an entrance and exit of the preheating chamber. The ingot preheating apparatus according to any one of claims 1 to 3, characterized in that: 5. The ingot preheating apparatus according to claim 1, wherein a flexible heat-resistant partition is provided at an entrance and exit of the preheating chamber. 6. The preheating chamber has a structure capable of accommodating a plurality of ingots, a surface combustion burner is provided at an outlet side of the ingot, and an exhaust portion is provided at an inlet side of the ingot. The apparatus for preheating an ingot according to any one of claims 1 to 5, 7. The ingot preheating apparatus according to claim 1, wherein the surface material of the surface combustion burner is formed by processing a heat-resistant metal fiber into a plate shape. 8. The preheating apparatus for an ingot according to claim 1, wherein the surface material of the surface combustion burner is formed by knitting heat-resistant metal fibers in a knit shape.