JPS5942206Y2 - Power supply structure of arc heating device for ladle - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a power supply structure for an arc heating device for a ladle, which reduces the impedance of the power supply path as much as possible, while simultaneously reducing the occupied space and preventing induction heating.

As shown in Fig. 1, the power supply structure conventionally adopted in ladle arc heating devices is such that the electrode lifting mechanism a (arm support mechanism a1 and reducer a2) is connected between the ladle and the flexible cable C. Therefore, the electrode support arm d supported by the electrode lifting mechanism a is inevitably long, and the electrode e and the terminal of the flexible cable C provided on the electrode support arm d are connected to each other. The bus line f that connects the lines must also become long.

Such a long bus bar is disadvantageous in terms of operation with high current short arcs.

Moreover, not only does it require a large space due to its structure, but considering the space used, there is little consideration given to induction heating caused by large currents.

The purpose of the present invention is to provide an electrode lifting mechanism above the ladle, and to provide an input terminal for supplying power to the electrode at a position near the ladle on the lower side of the electrode support arm that constitutes a part of this lifting mechanism. It is an object of the present invention to provide a power supply structure for an arc heating device for a ladle, which solves the drawbacks of conventional devices as much as possible.

The present invention will be described below with reference to the accompanying drawings.

FIG. 2 shows the power supply structure 1 of the ladle arc heating device according to the present invention.

This power supply structure 1 connects the ladle 2 to the electrode 5 of a power supply path (busbar) 6 to an electrode lifting device 4 provided on a pedestal 3 above the ladle 2 and an electrode 5 provided below the electrode lifting device 4. It mainly consists of an input terminal 7 provided at a nearby position, and the electrode 5 is inserted into an electrode holder 4a (described later) of the electrode lifting device 4 and held as described later, and is also provided with a displaceable power supply path, for example, a flexible A digital cable 8 is connected between the input terminal 7 and the power supply device 9.

The electrode elevating device 4 includes an electrode elevating mast 4e that is provided to be able to rise and fall freely from the mount 3 toward the ladle, and an electrode support arm 4c that is provided at right angles to the center of the mast and supports the electrode 5 at one end. It is mainly composed of.

An electrode holder 4a1 and an electrode gripping mechanism 4b attached to the electrode holder 4a are provided at one end of the electrode support arm 4c, and the electrode gripping mechanism 4 is installed at the other end of the electrode support arm 4c.
A cylinder 4d is provided for producing the function b.

Above the electrode elevating mass) 4e, there is a guide roller 4f that supports the electrode vertically movably;
A guide roller mount 4g that supports the wire, a motor 4h1, a speed reducer 4h2, and a wire hoisting and lowering device 4h that is connected to the wire drum 4h3 are respectively provided.

Further, the tip of the wire from the wire drum 4h3 is connected to the lower mounting plate 4e1 of the electrode lifting/lowering mass 4e.

In addition, the top of the electrode lifting/lowering mass) 4e is configured as an annular retaining structure 4e2 as required, and a buffering means (elastic body) is provided between the guide roller mount 4g and the retaining structure 4e2. ) For example, rubber 4j may be provided.

The bus bar 6 is stretched between the electrode holder 4a and a mounting plate 4C□ projecting from the lower side of the rear end of the electrode support arm 4C, and an input terminal 7 is provided there.

Incidentally, the ladle 2 is carried by a trolley 11 so as to be at an appropriate position with respect to the lid 10 into which the electrode 5 is inserted so as to be freely insertable and removable.

The operation and effect of the power supply structure 1 of the ladle arc heating device of the present invention constructed as described above will be described below.

It is now assumed that the ladle 2 has been transported by the cart 11 to a position 1 where the electrode 5 can be correctly inserted into the ladle 2.

Before power is supplied to the ladle 2 from the power supply device 9, the ladle 2 is lifted by a lifting device (not shown) on the trolley 11, and its peripheral end is brought into contact with the peripheral end of the lid 10.

Thereafter, the electrode 5 is lowered by the electrode lifting device 4 so as to generate a short arc with a large current.

After this short arc is generated, the electrode lifting device 4 is also used to adjust the amount of heat generated.

The current for supplying the amount of heat generated in this way flows through the power supply device 9, the flexible cable 8, the power supply path (mother Φ 6, electrode holder 4a, electrode 5, and molten steel 12), causing the above-mentioned short arc. 13 is generated between the electrode 5 and the molten steel 12, where electric energy is converted into thermal energy, and the molten steel is thus heated.

Such a heating operation can be performed with a larger current by the power supply structure of the present invention than in conventional devices.

In other words, the dimensions of the electrode lifting device 4 are no longer a factor that determines the length of the bus bar 6, but are used only as a means for guiding the bus bar 6 with the electrodes 51, so the length of the bus bar 6 is made as short as possible. This allows for high current operation, which reduces impedance as much as possible.

This reduction in power supply impedance not only reduces losses in the power supply path and increases efficiency, but also allows the arc to be as short as possible due to high current operation, which increases the size of the ladle resistance as the arc lengthens. By reducing the amount of heat transmitted to the side wall and lid of the ladle, it is possible to effectively input heat from the arc into the molten steel.

The combination of reduced wear on the ladle refractory from the long arc and reduced heat transferred to the side walls of the ladle can extend the life of the ladle.

Furthermore, even in the case of the above-mentioned high current operation, the bus bar through which the large current flows is located at a relatively large distance from the electrode support arm, electrode lifting mast, motor, etc., so it is difficult to apply induction heating to these. There is no danger.

In addition, since the electrode support arm can be made shorter, its weight can be reduced, and accordingly, the electrode lifting mast, wire hoisting and lowering device, etc. can be made lighter and smaller, and the space occupied as a whole can be reduced. This makes it possible to reduce the cost of the entire power supply structure.

Incidentally, upon completion of the high current operation as described above, the electrode is raised by the electrode lifting device, while the ladle 2 is moved to a height of 1
It is lowered by the trolley 11 and transported to the next processing step.

In the above embodiment, the electrode lifting device is not a limiting factor for the generatrix length and can be configured to reduce the weight of the electrode support arm and the like and to prevent the electrode from tilting. In addition to being a flexible cable, the displaceable power supply line 8 may be a bending and rotation type power supply mechanism.

It is even better if the power supply device 9 is of a type that moves in the same direction as the movement of the electrode lifting device 4.

As is clear from the above explanation, according to the present invention, the power supply impedance can be made smaller than that of the conventional device, so it is possible to operate at a higher current, and as a result, the loss in the power supply path is reduced. In addition to increasing efficiency by reducing the amount of heat generated by the arc, by shortening the arc due to the large current, it is possible to reduce wear and tear on the ladle reinforcement and to improve the heat input of the arc heat into the molten steel.

In addition, the life of the ladle can be extended by reducing wear and tear on the ladle's large parts and improving heat input, in other words, by reducing heat transmitted to the side walls of the ladle.

Means for reducing the power supply impedance to obtain such an effect also makes it possible to arrange various elements at relatively large distances from the bus bar, and these elements can be protected from induction heating due to large currents flowing through the bus bar, etc. was to be protected.

In addition to this, by shortening the electrode support arm,
This makes it possible to reduce the weight of the electrode lifting and lowering posts, to reduce the capacity of the wire hoisting and lowering device, and to reduce the space occupied by the power supply structure, all of which result in lower costs.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the power supply structure of a conventional ladle arc heating device, Fig. 2 is a diagram showing the power supply structure of the ladle arc heating device of the present invention, and Fig. 3 is a diagram showing the power supply structure of the ladle arc heating device of the present invention. FIG. In the figure, 1 is the power supply structure of the ladle arc heating device, 2 is the ladle, 3 is the pedestal, 4 is the electrode lifting device, 5 is the electrode, 6 is the bus bar,
7 is an input terminal, 8 is a flexible cable, and 9 is a power supply device.

Claims (1)

[Scope of utility model registration request] a pedestal provided above the ladle; an electrode elevating mast provided to be movable up and down in the direction of the ladle from the pedestal; and an electrode support arm provided on the mast and supporting an electrode at one end;
The other end of the support arm is provided with an input terminal provided in close proximity to the electrode to supply power, and a displaceable power supply path connected to the input terminal and connected to supply power from the power supply device. A power supply structure for an arc heating device for a ladle, characterized by the following.