JPH08110163A - Oxygen blowing device for electric furnace - Google Patents

Abstract

PURPOSE: To provide an oxygen blowing device, restricting the increase of generation of dust from the electric furnace by a method wherein a working port is not utilized is inserting an oxygen lance into the furnace to prevent the outflow of slag containing iron content out of the working port and minimize the opening area of a furnace body upon blowing oxygen in an oxygen blowing device for an electric furnace. CONSTITUTION: In a device for blowing oxygen gas from the upper part of an electric furnace, cutting solid metal such as scraps and the like, then melting them and refining the molten metal, a minimized opening is provided on the upper part of a furnace body or a furnace lid 2 and an oxygen lance is inserted through the opening upon blowing oxygen into the furnace, the lance is retreated and the opening is sealed by a movable water-cooled door 7 when the lance is not used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen or oxygen-containing gas blowing device for an electric furnace used for melting metal materials such as scrap and refining molten metal.

[0002]

2. Description of the Related Art As an electric furnace used for melting metal materials, refining molten metal, etc., it is attached to electrodes placed above the metal materials charged in the furnace and furnace walls such as the bottom and side walls of the furnace. A DC electric furnace that melts metal materials and smelts molten metal by passing an electric current between the electrodes and the three electrodes that are placed above the metallic materials charged in the furnace. An alternating current electric furnace for melting a metal material and refining a molten metal is known.
In this type of electric furnace, an operation of blowing oxygen and powder into the molten metal in the furnace is generally performed to accelerate the melting of the metal material and the refining of the molten metal. As described in Japanese Patent Application No. 5-177528, which was previously filed by a person, a method is used in which a non-consumable water-cooling lance is inserted from a working port of an electric furnace and oxygen and powder are blown.

[0003]

FIG. 2 is an explanatory diagram of a conventional electric furnace oxygen blowing device and the reach of an oxygen jet. The oxygen lance 3 and the powder blowing lance 9 are provided at the tip of the arm 10. This arm (not shown) can be swung by a swivel mechanism and moved so that the tip of the lance comes to the electric furnace working port 8.

In this system, the work door 11 provided on the work opening 8 is left open. As a result, in the electric furnace in which the molten steel yield is prioritized and the operation of the slag is suppressed as much as possible while the work opening is closed, the Fe from the work opening is opened by opening the work opening door.
It has a drawback that the yield of molten steel deteriorates due to the outflow of slag containing a large amount of O component. Also, if the door of the work opening is left open, the amount of infiltrated air from the work opening will increase, so in an electric furnace with a weak dust collection capability, the dust collection power at other locations will decrease, resulting in the It has the disadvantage of increasing dust generation from the furnace.

An object of the present invention is, in such a non-consumable type oxygen blowing device, when charging an oxygen lance into a furnace,
An object of the present invention is to provide an oxygen blowing device that suppresses deterioration of molten steel yield and increase of dust generation due to outflow of slag from the working port without using the working port.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides an oxygen blowing apparatus for cutting and melting solid metal such as scrap and refining molten metal, in which oxygen or oxygen-containing gas is blown from the upper part of an electric furnace. An opening is provided on the upper part of the body or the furnace lid, and an oxygen blowing device and a water cooling door that can be raised and lowered are respectively arranged on a lifting frame, and the oxygen blowing device and the water cooling door can be switched by a swivel switching device. Thus, when oxygen is blown in, an oxygen lance is charged through the opening, when the lance is not used, the lance is retracted, and the opening is formed so as to be closed by a movable water cooling door. Solved.

[0007]

According to the present invention, a working opening is opened by a method of providing a minimum opening for charging an oxygen supplying lance on the upper part of a furnace body or a furnace lid and charging the oxygen lance through the opening. Instead, it is possible to blow oxygen. When the oxygen lance is not used, it should be sealed with a water cooling door. By this method, outflow of slag from the work port can be prevented, and oxygen can be blown in without deteriorating the yield of molten steel. On the other hand, the work port remains closed, and when the lance is not used, the opening provided for charging the lance is closed by the water cooling door, so that it is possible to suppress an increase in dust generation due to the entering air. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1A shows a state in which the oxygen blowing device is attached to the opening. That is, in an oxygen blowing device for blowing solid oxygen such as scrap and melting solid metal such as scrap according to the present invention, and blowing oxygen or oxygen-containing gas from the upper inside of an electric furnace for refining molten metal, the furnace upper part or furnace lid 2 A minimum opening 14 is provided, and when the oxygen is blown, the oxygen lance 3 is charged from the opening 14 to blow the oxygen. When the lance is not used, the lance is lifted and retracted, and then the turning is switched. By using the device 6, the water cooling door 7 is provided with the opening 1
4 is an embodiment of an oxygen blowing apparatus for an electric furnace, which is characterized in that the apparatus is swung until it faces 4 and the opening 14 is closed by a lifting water-cooling door 7, and an outline of an oxygen blowing state is shown.

FIG. 1 (b) shows an outline of a state in which the lance 3 is raised and retracted when the lance is not used, and the opening 14 is closed by the water cooling door 7 after switching the turning. Figure 1 (c)
The schematic plan view of a turning switching device is shown. Reference numeral 1 is an electric furnace body, and 2 is a furnace lid. In this example, an opening 14 is provided in the upper part of the electric furnace body 1, and the oxygen lance 3 is connected to the lance lifting device 4
Thus, it is moved up and down along the lance lifting frame 5 and inserted into the furnace when oxygen is blown. In this embodiment, a system for carrying powder is provided in the oxygen lance 3 so that oxygen and powder can be blown from the oxygen lance 3.

On the other hand, when the oxygen lance 3 is not used,
The oxygen lance 3 is raised and retracted to the outside of the furnace, and the water cooling door 7 is opened by the swirl switching device 6 including a swivel cylinder or a swivel motor and a swivel frame (not shown).
4, and then, the water-cooling door 7 is lowered by the water-cooling door lifting device 12 along the water-cooling door lifting frame 13, and the water-cooling door outer peripheral frame is brought into close contact with the edge of the opening portion 14 to be hermetically sealed. ing. The water-cooling door 7 for sealing can reduce the amount of invading air into the furnace, suppress the increase of dust generation, and prevent clogging due to adhesion of metal to the opening 14.

[0011]

As described above, the non-consumable oxygen blowing apparatus for an electric furnace according to the present invention does not utilize a working port when charging an oxygen lance into the furnace, so that the slag flows out from the working port. Oxygen can be blown in without causing a deterioration in yield and an increase in dust generation.

[Brief description of drawings]

FIG. 1 is an embodiment of an oxygen blowing device according to the present invention,
(A) is a schematic diagram when a lance is used, (b) is a schematic diagram when a lance is not used, and (c) is a schematic plan view of a turning switching device.

FIG. 2 is an explanatory view of a conventional electric furnace oxygen blowing device and an oxygen jet flow range.

[Explanation of symbols]

 1 Electric Furnace Body 2 Furnace Lid 3 Oxygen Lance 4 Lance Lifting Device 5 Lance Lifting Frame 6 Swing Switching Device 7 Water Cooling Door 8 Working Port 9 Powder Lance 10 Arm 11 Working Port Door 12 Water Cooling Door Lifting Device 13 Water Cooling Door Lifting Frame 14 Aperture

Claims (1)

[Claims] 1. An oxygen blowing device for cutting solid metal such as scrap, melting it, and refining the molten metal by blowing oxygen or an oxygen-containing gas from the upper inside of an electric furnace. In addition to providing a section, an oxygen blowing device and a water cooling door that can be raised and lowered are respectively arranged on the lifting frame, and the oxygen blowing device and the water cooling door can be switched by a turning switching device and can be attached to and detached from the opening. An oxygen blowing device for an electric furnace characterized by being formed as possible.