JPH06228668A - Method and apparatus for melting scrap - Google Patents

Abstract

PURPOSE:To simplify an apparatus while continuing steel tapping from a scrap melting furnace as long as possible. CONSTITUTION:A furnace opening part 4 at the top part, an exhaust gas discharging hole 5 at the upper part, an exhaust gas blowing hole 6 and a secondary combustion tuyere 7 at the intermediate part and a bottom blowing tuyere 8 and a steel tapping hole 14 at the bottom part, are arranged in the melting furnace 1. The three sets of melting furnaces 1 are arranged side by side and the exhaust gas discharging hole 5 and the exhaust gas blowing hole 6 in the other melting furnace are communicated, and the cyclic operation of a melting and refining process, scrap preheating process and scrap and coke packing process after steel tapping is executed. Therefore, the steel tapping of the melting furnace 1 can be continued as long as possible and as the preheated scrap 2 can be melted in the position, a means for moving the high temp. scrap is unnecessitated and the apparatus can be simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scrap melting method and apparatus.

[0002]

2. Description of the Related Art Conventionally, an electric furnace has been used for melting and refining iron scrap (scrap), but the melting and refining of scrap by this electric furnace is extremely expensive.

In order to reduce the melting cost and improve the productivity, it is known to collect the exhaust gas from the melting furnace and use it for preheating the scrap (see, for example, Japanese Patent Publication No. 60-56401). ).

However, in such a conventional general scrap melting furnace, 1) scrap melting and refining is carried out by using one melting furnace, so that tapping or tapping is intermittent, and 2) scrap preheating furnace Since it is combined with the melting furnace, there is a problem that a transfer means for charging the preheated scrap into the melting furnace is required.

[0005]

Therefore, the present invention has been made to solve such a problem, and the gist thereof is: 1) a furnace opening at the top of the melting furnace, an exhaust gas discharge opening at the upper part, Three melting furnaces each having an exhaust gas inlet and a secondary combustion tuyere at the middle part and a bottom blowing tuyere at the bottom were installed side by side, and the exhaust gas outlet and the exhaust gas inlets of other melting furnaces were connected via valves. The method for melting scrap is characterized by operating three melting furnaces in communication with each other in sequence by opening and closing valves for each process. 2) Furnace mouth at the top of the melting furnace and at the upper part of the melting furnace. Three smelting furnaces, each equipped with an exhaust gas outlet, an exhaust gas inlet and secondary combustion tuyere in the middle, and a bottom blowing tuyere at the bottom, were installed in parallel, and the exhaust gas outlet and the exhaust gas inlets of other melting furnaces were installed. The communication passage communicates with the exhaust gas main passage through a valve. In dissolving apparatus scrap

[0006]

The present invention will be described in detail with reference to the embodiments shown in the accompanying drawings. First, the outline of the scrap melting furnace 1 of the present embodiment will be described. The scrap 2 and the coke 3 are charged into the melting furnace 1 and the scrap 2 is melted by the combustion heat of the coke 3. The melting furnace 1 has three identical structures and is melted in parallel. The refining process, the scrap preheating process, and the scrap filling process are sequentially cycled.

In FIG. 1, A is a diagram of a scrap filling process after tapping, B is a diagram of a preheating process, and C is a diagram of a melting and refining process.

Each of the melting furnaces 1A, 1B and 1C is provided with a furnace port 4 at the top thereof, an exhaust gas discharge port 5 at the upper part thereof, and an exhaust gas injection port 6 and secondary combustion at an intermediate part thereof. A tuyere 7 is provided, and a plurality of bottom blowing tuyeres 8 are provided at the bottom.

The exhaust gas outlet 5A of the melting furnace 1A communicates with the exhaust gas inlet 6C of the melting furnace 1C and also communicates with the exhaust gas main passage 9. Exhaust gas exhaust port 5 of melting furnace 1B
B communicates with the exhaust gas inlet 6A of the melting furnace 1A and also communicates with the exhaust gas main passage 9. The exhaust gas discharge port 5C of the melting furnace 1C communicates with the exhaust gas blowing port 6B of the melting furnace 1B and also communicates with the exhaust gas main passage 9.
In addition, the secondary combustion tuyere 7 of each melting furnace 1A, 1B, 1C,
Each of the melting furnaces 1 communicates with the combustion-supporting gas main passage 10.
Bottom blown tuyere 8 of A, 1B, 1C is the bottom blown gas main passage 1
It communicates with 1.

Then, in these passages 9, 10 and 11, the automatic open / close valves 12A and 1 are arranged at the positions shown in FIG.
2B, 12C, 12-1A, 12-1B, 12-1C,
12 'and 12 "are provided. Of course, the valves shown in black in FIG. 1 are in the closed state.
In Fig. 13, 13 is an iron bath and 14 is a tap hole.

Next, the operation of this embodiment will be described. Melting furnace 1
At A, the scrap 2 and the coke 3 are charged from the furnace port 4. At that time, each valve 12A, 12-1A, 1
2'and 12 "are closed. At the time of this charging, the coke 3 is first charged to protect the hearth and the coke
The coke 3 is made reddenable by the bottom blown gas from the bottom blower opening 8, and then a packed layer of scrap coke is formed.

Next, in the adjoining melting furnace 1B, the exhaust gas generated during the melting and refining process in the adjoining melting furnace 1C is discharged from the exhaust gas discharge port 5C into the scrap coke packed bed and blown into the exhaust gas. Blow from the mouth 6B to preheat the scrap 2. Therefore, the exhaust gas discharge port 5B of the melting furnace 1B
And the valve 12B of the exhaust gas inlet 6B is open.

Next, in the melting furnace 1C, the combustion gas and the bottom blowing gas are blown into the preheated scrap 2 from the secondary combustion tuyere 7 and the bottom blowing tuyere 8 to produce the coke 3 and the auxiliary fuel. The scrap 2 is melted by the combustion heat of. Therefore, in the melting furnace 1C, the valve 12C of the exhaust gas injection port 6C
Only closed.

As described above, the valves 12A, 12B, 12C, 12-1A, 12 are used in the melting furnaces 1A, 1B, 1C.
-1B, 12-1C, 12 ', 12 "switching operation, filling process A after tapping → preheating process B → melting and refining process C
The above steps are sequentially repeated in a cycle. In the above embodiment, the exhaust gas discharge ports 5A, 5 of each melting furnace
The valves 12 provided in B and 5C, 12B and 12C, may be omitted if necessary.

[0015]

According to the present invention, three melting furnaces having the same structure are used.
Since the exhaust gas was connected to other melting furnaces via valves and used for preheating of scraps, the melting and refining process, the scrap preheating process, and the scrap and coke filling process after tapping were carried out. In this way, the tapping can be continuously carried out in a cyclic manner, and the preheated scrap can be melted and refined in the same position only by operating the valve, and a moving means for high temperature scrap is not required. As a result, the equipment can be simplified, the mechanical reliability can be improved, and automation can be performed.

[Brief description of drawings]

FIG. 1 is a flow chart of an embodiment of the present invention.

[Explanation of symbols]

1A, 1B, 1C ... Melting furnace, 4 ... Furnace mouth, 5A, 5B, 5
C ... Exhaust gas outlet, 6A, 6B, 6C ... Exhaust gas inlet,
7 ... Secondary combustion tuyere, 8 ... Bottom blowing tuyere, 9 ... Exhaust gas main passage, 12A, 12B, 12C, 12-1A, 12-1
B, 12-1C, 12 ', 12 "... Valve

Claims (2)

[Claims] 1. Three melting furnaces each having a furnace mouth at the top of the melting furnace, an exhaust gas outlet at the upper portion, an exhaust gas inlet and a secondary combustion tuyere at the middle portion, and a bottom blowing tuyere at the bottom are arranged in parallel. The exhaust gas outlet and the exhaust gas inlet of another melting furnace are connected to each other through a valve, and three melting furnaces are sequentially operated by opening and closing the valve for each process. How to dissolve scrap. 2. Three melting furnaces are provided side by side, each having a furnace opening at the top of the melting furnace, an exhaust gas outlet at the upper part, an exhaust gas inlet and a secondary combustion tuyere at the middle part, and a bottom blowing tuyere at the bottom. The scrap melting apparatus is characterized in that a communication passage that connects the exhaust gas outlet and the exhaust gas inlet of another melting furnace is connected to the exhaust gas main passage through a valve.