Melting and iron-smelting device of heat storage type electric arc furnace

[0023] Example 1

[0024] The regenerative electric arc furnace according to the present invention is as follows figure 1 As shown, it includes a furnace body 4, a furnace cover 1, a feeding device and a discharging device. The lower part of the furnace body 4 has a molten iron outlet 7, such as image 3 As shown, there are three electrode insertion holes 19 on the furnace cover 1, which are respectively inserted into the electrodes 2, and the three electrode insertion holes are distributed in a triangle. Outside the furnace body 4, a pair of combustion chambers 11a, 11b, a pair of heat accumulators 12a, 12b, and a pair of coal gasification tanks 9a, 9b are installed on opposite sides of the furnace body 2. There is a three-layer coal grid 10 in the coal gasification tank. The coal grid is a mesh rectangular structure and is made of wire mesh. The upper part of the coal grid has a coal inlet, and the lower part has a coal ash outlet. The coal inlet and the coal ash outlet are sealed with covers. One end of the coal gasification tank is connected to the furnace body 4 of the electric arc furnace through a connecting pipe 8, and the other end is connected to the combustion chamber. The two ends of the gas tank are connected with bypass 5, and the outlet, inlet and bypass of the gas tank are provided with valves 6. One end of the heat accumulator is connected with the combustion chamber, and the other end is respectively connected with the blower 14 and the exhaust system. The other two paths of the combustion chamber are respectively connected with the combustion air pipeline and the fuel pipeline. The outlet of the blower 14 is divided into four paths, which are respectively connected with two combustion chambers and two heat accumulators, and each path is equipped with a valve 6. The fuel pipeline connected with the combustion chamber and the exhaust gas discharge pipeline connected with the heat accumulator are also equipped with valves. The exhaust system includes a cyclone 15, a bag filter 16, an induced draft fan 17 and a chimney 18. The combustion chamber is provided with a burner, which is a gas fuel burner, and the combustion air and fuel pipelines are connected to the burner. The two combustion chambers alternately burn to produce high-temperature flue gas, and the two heat accumulators alternately store and release heat. The precipitated gas is the gas produced during the reduction of metal iron oxide, which contains a large amount of CO and H 2.

[0025] The heat accumulators 12a, 12b are equipped with a heat storage body 13, and the heat storage body is a ceramic spherical body. The furnace body and furnace cover of the electric arc furnace are of steel structure. The furnace body 4 and the furnace cover 1, and the electrode 2 and the furnace cover 1 are in a sealed connection with a water cooling jacket. The electric arc furnace is equipped with a pressure vent valve 3 as an explosion-proof device. The outer shells of the coal gasification tank 9 and the bypass 5 are lined with refractory insulation materials. The shells of the electric arc furnace body 4 and the furnace cover 1 are lined with refractory insulation materials, and the shells of the combustion chamber, the heat accumulator and the connecting pipelines are lined with refractory insulation materials.

[0026] The working principle of the present invention is that the reduced material is placed in the electric arc furnace body 4, the combustion chamber 11a is started first, and the valves of the fuel passage and the air passage are opened, so that the air and fuel are burned in the combustion chamber to produce high-temperature flue gas Enter the adjacent coal gasification tank 9a, and pass through the three-layer coal grid in the coal gasification tank in turn to make the high-temperature CO in the flue gas 2 It reacts with coal to generate CO. The excess oxygen in the combustion-supporting air is also reduced in the coal gasification tank. The high-temperature reducing gas exiting the coal gasification tank enters the reduction furnace through the connecting pipe 8 and reacts with the materials. During this process, coal gasification The bypass of the box 9a is closed, the valve connected to the coal gasification box 9b on the other side of the reduction furnace is closed, and the corresponding bypass 5 channel is opened. The CO generated during the reduction process enters the combustion chamber 11b, and passes into the combustion chamber 11b through the burner The combustion-supporting air completely combusts the combustible components in the gas from the electric arc furnace. The high-temperature flue gas produced passes through the heat accumulator 12b, transfers the waste heat to the heat accumulator 13, and is discharged from the flue gas pipeline at the end of the accumulator through the cyclone. Separator, bag filter, induced draft fan, chimney discharge into the atmosphere. As the entire equipment works in this way, the temperature of the flue gas out of the heat accumulator gradually rises, and the equipment reverses operation when the flue gas at the outlet of the heat accumulator reaches a specified temperature. The cold air is blown in by the blower 14 and passes through the heat accumulator 12b, where the heat accumulator releases heat to heat the air. The high-temperature air leaving the heat accumulator enters the combustion chamber 11b and mixes and burns with the fuel injected by the burner to produce high-temperature smoke The gas enters the adjacent coal gasification tank 9b and reacts with the coal in the coal grids in the coal gasification tank 9b. The reducing gas exiting 9b enters the electric arc furnace body 4 through the connecting pipe 8 to react. During the process, the bypass of the coal gasification tank 9b is closed, while the outlet and inlet valves of the coal gasification tank 9a on the other side of the electric arc furnace are closed, and the bypass 5 valve 6 is opened, and the gas out of the electric arc furnace enters the combustion through the bypass The chamber 11a is mixed and combusted with the combustion-supporting air entering the combustion chamber. After passing through the heat accumulator 12a, the waste flue gas is transferred to the heat accumulator, and then discharged through the flue gas pipeline at the end of the accumulator, and passed through the cyclone separator, The bag filter, induced draft fan and chimney are discharged into the atmosphere. The reversing operation of the two combustion chambers 11a, 11b, the two heat accumulators 12a, 12b and the two coal gasification tanks 9a, 9b are controlled by setting the temperature of the flue gas outlet of the heat accumulator. When the flue gas from the heat accumulator reaches After the temperature is set, the direction of the air flow is automatically changed, and the combustion chamber on this side is converted from the combustion electric arc furnace to the combustion fuel. The set temperature of the heat accumulator flue gas is 70~150℃, and the specific temperature is set according to the process requirements. The whole process is automatically controlled, and the reversing operation is realized by switching each valve.

[0027] When the material in the arc furnace body reaches a certain temperature and reduction degree, turn off the heat accumulators, combustion chamber and coal gasification box on both sides, insert the electrode 2 on the top of the arc furnace into the furnace, and continue to heat the reduced materials in the arc furnace to complete Melt, open the molten iron outflow port 7 at the bottom of the electric arc furnace, and proceed to the next furnace after the molten iron is completely discharged.

[0028] Example 2

[0029] Another embodiment of the present invention is that three sets of regenerative electric arc furnace melting iron-making devices are installed side by side in series to operate. Each device is equipped with two sets of heat storage/coal gasification equipment 23, which are located on opposite sides of the furnace body. Location, the heat storage/coal gasification equipment includes a combustion chamber, a heat accumulator, a coal gasification tank and connecting pipelines. The air supply system, fuel system and exhaust emission system are shared equipment. The operation modes of the electric arc furnace, heat accumulator, combustion chamber, and gas tank of each set of devices are the same as in Example 1. Such as Figure 4 As shown, the furnace bodies 4a, 4b, and 4c of the three sets of electric arc furnaces are connected side by side. The furnace body 4a and the furnace body 4b, and the furnace body 4b and the furnace body 4c are provided with connecting holes 20, and the connecting holes are provided with inserts. The plate valve 21 is connected by pipelines between the furnace bodies 4a and 4c, and a plug-in valve is provided for gas circulation. The three furnace bodies alternately perform heating, reduction and melting processes. When the reduced materials in the furnace body 4a complete the reduction process and melt, the materials in the other two furnace bodies 4b and 4c are heating up and reducing. At this time, the plug-in valve 21 is opened, and the precipitated gas generated in the furnace body 4a enters the furnace bodies 4b, 4c through the connecting hole 20 and pipelines to be used as reducing gas and combustion gas. After the furnace body 4a is melted, when the molten iron and the charging material are discharged through the molten iron outflow port 7, the flap valves on both sides of the furnace body are closed. When the material in the furnace body 4b is melted, the precipitated gas in the furnace body 4b enters the furnace bodies 4a, 4b through the connection holes 20 between the furnace bodies on both sides. Three electric arc furnaces carry out loading and unloading, reduction and melting processes in sequence. The smelting reduction operation process of each device is the same as that of Example 1, and will not be repeated. The purpose of using multiple electric arc furnaces in series operation is to make full use of the precipitated gas generated during the melting process for the reduction process of the reduced materials in the furnace body, so that the precipitated gas during the smelting process can be fully utilized, saving energy, and forming large-scale production. Improve ironmaking production capacity.

[0030] Example 3

[0031] Another embodiment of the present invention is as Figure 5 Shown are three electric arc furnaces arranged in a ring shape. The three electric arc furnace bodies 4a, 4b, and 4c are arranged in a triangular shape in a ring shape. Each furnace body is installed close to the other two furnace bodies. A connecting hole and a plug-in valve 21 are provided between each two furnace bodies. Each electric arc furnace is provided with two sets of heat storage/gasification equipment 23, which are located on the two wings of the furnace body, and a set of heat storage/gasification equipment 23 of two adjacent electric arc furnaces are arranged together in a "her" shape. The air supply system, fuel system and exhaust emission system are shared equipment. There is an electrode hanging column 22 in the middle of the three furnace bodies for hanging the electrodes, and the electrodes are inserted between the furnace bodies in turn to carry out the process of melting the reduced iron. The operation mode of this embodiment is the same as that of Embodiment 2. When one of the furnace bodies is melting, the other two are in the heating or reducing process, the flapper valve 21 is opened to allow the precipitated gas to enter the adjacent two furnace bodies. After the melting process is completed, close the insert valve of the furnace body and the adjacent furnace body, discharge the material and load new raw materials, then open the valve and put in the gas for heating and reduction process. With this type of installation, three electric arc furnaces use a set of electrodes. By rotating the electrodes, the electrodes are inserted into the furnace body that needs to enter the melting process in turn. The electrodes can be omitted during heating and reduction to save electrode materials and investment. The ring arrangement is adopted, the equipment is compactly installed, which further saves the space, and further expands the production capacity in the limited space.