CN111811268A - A layered combined electrode submerged melting furnace and its control method - Google Patents

Abstract

The invention discloses a layered combined electrode submerged arc melting furnace and a control method thereof. The electrode system comprises an upper electrode holder, a lower electrode holder, an electrode copper tile, a middle shaft cathode, a peripheral hollow cathode, a furnace bottom anode, a power supply, a transformer, a motor crawler device, a master control computer and a voltmeter. The furnace body comprises a furnace cover, a furnace shell, a furnace lining, a furnace body support, a water pump and a thermocouple. By arranging the peripheral hollow cathode electrode, current can flow through the furnace burden close to the side of the furnace lining. Compared with the traditional single-electrode submerged arc melting furnace, the layered combined electrode submerged arc melting furnace has the advantages that not only the joule heat extreme value is reduced, but also the distribution range of joule heat in the furnace is enlarged, the problem of uneven distribution of furnace charge heat in the furnace is effectively solved, meanwhile, the utilization efficiency of energy in the furnace and the melting rate of the furnace charge are also improved, and the layered combined electrode submerged arc melting furnace can be widely applied to the metallurgical and chemical industry.

Description

A layered combined electrode submerged melting furnace and its control method

technical field

The invention belongs to the field of metallurgical chemical production, and particularly relates to a layered combined electrode submerged thermal smelting furnace and a control method thereof.

Background technique

As an important part of industrial production, submerged melting furnace is widely used in steel and non-ferrous metal smelting process. In recent years, with the development of society and the advancement of science and technology, the energy consumption, production capacity and emission requirements of submerged arc melting furnaces have become higher and higher. applied on the furnace. In the prior art, the electrodes of submerged arc melting furnaces are mostly cylindrical electrodes. When the electrodes are inserted into the charge for submerged arc operation, the metal is smelted by the energy of the arc at the end of the electrode and the resistance heat generated by the current flowing through the charge. However, in this way, the heat in the furnace is concentrated at the ends of the electrodes, and the heat distribution in the furnace is not uniform. The charge at the edge can only receive heat through two heat transport modes, thermal conduction and natural convection, which seriously weakens the smelting performance of the submerged thermal smelting furnace. To sum up, how to effectively improve the problem of uneven heat distribution in the submerged arc smelting furnace is an urgent problem to be solved by those skilled in the art at present.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method that can not only reduce the extreme value of Joule heat in the furnace, but also expand the distribution range of Joule heat in the furnace, effectively improve the problem of uneven heat distribution of the furnace charge, and also improve the energy consumption in the furnace. A layered combined electrode submerged smelting furnace utilizing efficiency and charge melting rate and its control method.

In order to achieve the above purpose, the layered combined electrode submerged thermal smelting furnace of the present invention includes an electrode system and a furnace body system, and the electrode system includes first and second motor crawler devices connected to the general control computer. The upper electrode holder and the lower electrode holder are respectively fixed on the motor crawler device. The upper and lower electrode holders are respectively clamped by the electrode copper tile with the central axis cathode electrode and the peripheral hollow cathode electrode, and the central axis cathode electrode passes through the peripheral hollow cathode. Electrodes, a furnace body is arranged at the lower end of the central axis cathode electrode and the peripheral hollow cathode electrode, the central axis cathode electrode and the peripheral hollow cathode electrode are inserted into the furnace body, and the furnace body system includes a hollow structure with cooling water inlet and outlet. The furnace shell is equipped with a furnace cover on the top of the furnace shell, a furnace body support with a hollow structure with cooling water inlet and outlet at the bottom, a furnace lining is arranged inside the furnace shell, and the furnace body on the upper part of the furnace body support is equipped with a furnace bottom connected to the power supply Anode electrode, the upper electrode holder is connected to one side electrode of the transformer, the other side electrode of the transformer is connected to the power supply; the lower electrode holder is connected to the power supply; between the upper electrode holder and the transformer, the lower electrode holder is connected to the power supply. The first and second voltmeters for monitoring voltage are respectively installed between the power supplies. The cooling water inlet supported by the furnace shell and the furnace body is installed with a water pump and a water inlet thermocouple, and its outlet is installed with a water outlet thermocouple for monitoring water temperature. .

The central axis cathode electrode, the peripheral hollow cathode electrode, the furnace shell, the furnace lining and the furnace bottom anode electrode are coaxially installed.

The distance from the end of the peripheral hollow cathode electrode to the upper part of the anode electrode at the furnace bottom is 1.0 to 2.0 times the distance from the end of the central axis cathode electrode to the upper part of the anode electrode at the furnace bottom.

The cross-sectional area of the peripheral hollow cathode electrode is 1.0-1.5 times the cross-sectional area of the central axis cathode electrode.

The absolute value of the voltage loaded to the central axis cathode electrode is 0.8-0.9 times the absolute value of the voltage loaded to the peripheral hollow cathode electrode.

Said transformer and voltmeter are also respectively connected with the master control computer.

The water pump, the water inlet thermocouple and the water outlet thermocouple are respectively connected with the general control computer.

The power source is a DC power source or an AC power source.

The control method of the layered combined electrode submerged thermal smelting furnace of the present invention is as follows:

1) First, the motor crawler device is controlled by the general control computer to drive the peripheral hollow cathode electrode and the central axis cathode electrode to be inserted into the furnace lining;

2) Add raw ore until the charge completely covers the end of the peripheral hollow cathode electrode;

3) Drive the cooling water into the furnace shell and furnace body support through the water pump, and observe the value of the thermocouple at the water inlet and the thermocouple at the water outlet. If the temperature exceeds the set temperature, adjust the water pump through the total control computer to increase the cooling water flow;

3) Turn on the power supply and adjust the transformer so that the voltage value U1 of the first voltmeter is 0.8-0.9 times the voltage value U2 _of the _second voltmeter (16);

4) During the smelting process, both U ₁ and U ₂ will fluctuate. At this time, the transformer is adjusted by the total control computer to maintain the relationship of U ₁ =(0.8～0.9)U ₂ ;

5) When the smelting is completed, first turn off the power supply, then control the motor crawler device through the general control computer, drive the peripheral hollow cathode electrode and the central axis cathode electrode to leave the furnace lining, and then open the discharge port on the furnace shell to discharge the liquid ore and slag.

The raw material ore is iron ore, chromium ore, manganese ore, silica, ferrosilicon, scrap iron, calcium oxide or carbonaceous reducing agent.

The submerged arc smelting furnace provided by the invention has a reasonable structure design, and by arranging electrodes with different immersion depths in the charge, it can effectively heat the charge at various positions in the furnace, and can effectively improve the heat distribution in the submerged arc smelting furnace. It not only significantly shortens the melting and reduction time of the charge in the furnace, but also significantly improves the utilization efficiency of the electric energy in the furnace, which can be widely used in the metallurgical and chemical industry.

Description of drawings

Fig. 1 is the schematic diagram of the submerged thermal smelting furnace structure of the present invention;

Fig. 2 is the electrode system schematic diagram of the submerged thermal smelting furnace of the present invention;

Fig. 3 is a contrast cloud diagram of Joule heat heat distribution in the furnace when smelting h13 die steel in a traditional submerged arc melting furnace and a layered combined electrode submerged arc melting furnace;

Figure 4 is a graph showing the change of the melting rate of the charge of the traditional submerged smelting furnace and the layered combined electrode smelting furnace with time;

FIG. 5 is a graph showing the influence of the voltage of the peripheral hollow cathode electrode on the energy utilization efficiency (melting rate=90%).

Label name in the figure: 1. Upper electrode holder, 2. Lower electrode holder, 3. Electrode copper tile, 4. Central axis cathode electrode, 5. Peripheral hollow cathode electrode, 6. Furnace cover, 7. Furnace shell, 8 . Furnace lining, 9. Furnace body support, 10. Furnace bottom anode, 11. Power supply, 12. Transformer, 13. First motor crawler device, 13-1. Second motor crawler device, 14. Total control computer, 15. First voltmeter, 16. Second voltmeter, 17. Water pump, 18. Water inlet thermocouple, 18-1. Water outlet thermocouple.

Detailed ways

The technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention.

Referring to FIG. 1 and FIG. 2 , the layered combined electrode submerged thermal smelting furnace of the present invention includes an electrode system and a furnace body system, and the electrode system includes first and second motor crawler devices 13 and 13- 1. An upper electrode holder 1 and a lower electrode holder 2 are respectively fixed on the first and second motor crawler devices 13 and 13-1. The upper and lower electrode holders 1 and 2 are respectively clamped by electrode copper tiles 3. The central axis cathode electrode 4 and the peripheral hollow cathode electrode 5, the central axis cathode electrode 4 passes through the peripheral hollow cathode electrode 5, and a furnace body is provided at the lower end of the central axis cathode electrode 4 and the peripheral hollow cathode electrode 5, and the central axis cathode electrode 4 and the peripheral hollow cathode electrode 5 are provided with a furnace body. The hollow cathode electrode 5 is inserted into the furnace body. The furnace body system includes a furnace shell 7 with a hollow structure with cooling water inlet and outlet. A furnace cover 6 is assembled on the top of the furnace shell 7, and a hollow structure with cooling water is arranged at the bottom. The furnace body support 9 for the water inlet and outlet, the furnace lining 8 is arranged inside the furnace shell 7, the furnace body on the upper part of the furnace body support 9 is equipped with the furnace bottom anode 10 connected with the power source 11, the upper electrode holder 1 and the side of the transformer 12 The electrodes on the other side of the transformer 12 are connected to the power source 11; the lower electrode holder 2 is connected to the power source 11; between the upper electrode holder 1 and the transformer 12, the lower electrode holder 2 and the power source 11 are respectively The first and second voltmeters 15 and 16 for monitoring voltage are installed, a water pump 17 and a water inlet thermocouple 18 are installed at the cooling water inlet of the furnace shell 7 and the furnace body support 9, and a water outlet for monitoring the water temperature is installed at the outlet. Thermocouple 18-1.

The central axis cathode electrode 4, the peripheral hollow cathode electrode 5, the furnace shell 7, the furnace lining 8 and the furnace bottom anode electrode 10 are installed coaxially; the distance from the end of the peripheral hollow cathode electrode 5 to the upper part of the furnace bottom anode electrode 10 is the central axis cathode electrode 4 The distance from the end to the upper part of the anode electrode 10 at the furnace bottom is 1.0 to 2.0 times; the cross-sectional area of the peripheral hollow cathode electrode 5 is 1.0 to 1.5 times the cross-sectional area of the central axis cathode electrode 4; the voltage loaded to the central axis cathode electrode 4 is absolutely The value is 0.8 to 0.9 times the absolute value of the voltage loaded to the peripheral hollow cathode electrode 5; the transformer 12, the voltmeters 15 and 16, the water pump 17, the water inlet thermocouple 18 and the water outlet thermocouple 18-1 are respectively connected to the main control computer ; The power supply 11 is a DC power supply or an AC power supply.

When applying the submerged thermal smelting furnace provided by the present invention, the whole work flow is:

1) First, the motor crawler device 13 is controlled by the general control computer 14 to drive the peripheral hollow cathode electrode 5 and the central axis cathode electrode 4 to be inserted into the furnace lining 8;

2) Add raw ore until the charge completely covers the end of the peripheral hollow cathode electrode 5;

3) Drive the cooling water into the furnace shell 7 and the furnace body support 9 through the water pump 17, and observe the values on the water inlet thermocouple 18 and the water outlet thermocouple 18-1. If it exceeds the set temperature, pass the total control computer 14. Adjust the water pump to increase the cooling water flow;

3) Turn on the power supply 11 and adjust the transformer 12 so that the voltage value U1 of the first voltmeter 15 is 0.8-0.9 times the voltage value U2 _of the _second voltmeter 16;

4) During the smelting process, both U ₁ and U ₂ will fluctuate. At this time, the transformer 12 is adjusted by the total control computer 14 to maintain the relationship of U ₁ =(0.8～0.9)U ₂ ;

5) When the smelting is completed, first turn off the power supply 11, then control the motor crawler device 13 through the general control computer 14, drive the peripheral hollow cathode electrode 5 and the central axis cathode electrode 4 to leave the furnace lining (8), and then open the outlet on the furnace shell 7. The material port discharges liquid ore and slag.

10. The control method of the layered combined electrode submerged thermal smelting furnace according to claim 9, wherein the raw material ore is iron ore, chromium ore, manganese ore, silica, ferrosilicon, scrap iron, calcium oxide or carbonaceous reducing agents.

Numerical simulation experiment method is a relatively mature method to study multi-physics flow and heat transfer. Many research institutions analyze the physical field distribution and smelting performance of submerged arc smelting furnace through numerical simulation. In order to facilitate the simulation solution, only the furnace charge and electrodes are selected for simulation calculation. Figure 3 is a comparison cloud diagram of Joule heat heat distribution in the furnace when smelting h13 die steel between the traditional submerged arc melting furnace and the layered combined electrode submerged arc melting furnace. Big time comparison. It can be seen from the figure that compared with the traditional submerged arc melting furnace, the heat distribution in the layered combined electrode submerged arc melting furnace is more uniform because part of the current flows out from the end of the hollow electrode. Compared with the traditional smelting furnace, the extreme value of Joule heat in the furnace is reduced by 20%, and the operation of the smelting furnace is safer.

FIG. 4 is a graph showing the change of the melting rate of the charge of the traditional submerged smelting furnace and the layered combined electrode smelting furnace with time. As can be seen from the figure, compared with the traditional submerged smelting furnace, the layered combined electrode smelting furnace has a lower Joule heat extreme value, so the time point when the furnace charge begins to melt is delayed, and in the initial stage, the furnace begins to melt. Compared with the traditional submerged thermal melting furnace, the melting rate of the inner charge has not been high. However, with the passage of smelting time, due to the more uniform heat distribution in the layered combined electrode submerged arc melting furnace, the melting rate of the charge is rapidly increased, and it exceeds the melting rate of the charge in the traditional submerged arc melting furnace in about 4000s. At 5400s, the melting volume of the charge in the layered combined electrode submerged arc smelting furnace reaches 90% of the charge volume, while it takes 5700s for the melting volume of the charge in the traditional submerged arc melting furnace to reach 90% of the charge volume.

Fig. 5 is a graph showing the influence law of the voltage of the peripheral hollow cathode electrode on the energy utilization efficiency when the melting rate of the charge is 90%. It can be seen from the figure that as the voltage increases, the overall energy utilization efficiency in the furnace is increasing. Within the research scope, the energy utilization efficiency in the furnace is increased by an average of 5.3% compared with the traditional submerged thermal smelting furnace. It can be seen from this that the layered combined electrode submerged arc smelting proposed in this patent not only speeds up the melting rate of the charge, but also improves the energy utilization efficiency compared with the traditional submerged arc smelting furnace. The comprehensive smelting of the submerged arc furnace Performance has been optimized.

Claims (10)

1. a layered combined electrode submerged thermal smelting furnace, is characterized in that, comprises electrode system and furnace body system, and described electrode system comprises the first, second motor crawler device (13, 13-1), an upper electrode holder (1) and a lower electrode holder (2) are respectively fixed on the first and second motor crawler devices (13, 13-1), and the upper and lower electrode holders (1, 2) The central axis cathode electrode (4) and the peripheral hollow cathode electrode (5) are respectively clamped by the electrode copper tile (3), the central axis cathode electrode (4) passes through the peripheral hollow cathode electrode (5), and the central axis cathode electrode (4) passes through the peripheral hollow cathode electrode (5). A furnace body is provided at the lower end of the electrode (4) and the peripheral hollow cathode electrode (5), the central axis cathode electrode (4) and the peripheral hollow cathode electrode (5) are inserted into the furnace body, and the furnace body system includes a hollow structure with A furnace shell (7) with cooling water inlet and outlet, a furnace cover (6) is assembled on the top of the furnace shell (7), and a furnace body support (9) with a cooling water inlet and outlet with a hollow structure is arranged at the bottom, and the furnace shell ( 7) The furnace lining (8) is arranged on the inner side, the furnace body on the upper part of the furnace body support (9) is equipped with the furnace bottom anode electrode (10) connected with the power supply (11), and the upper electrode holder (1) is connected with the transformer (12). The side electrodes are connected, the other side electrode of the transformer (12) is connected with the power supply (11); the lower electrode holder (2) is connected with the power supply (11); the upper electrode holder (1) and the transformer (12) are connected Between the lower electrode holder (2) and the power supply (11), the first and second voltmeters (15, 16) for monitoring voltage are respectively installed, and the cooling of the furnace shell (7) and the furnace body support (9) A water pump (17) and a water inlet thermocouple (18) are installed at the water inlet, and a water outlet thermocouple (18-1) for monitoring the water temperature is installed at the outlet. 2. The layered combined electrode ore-thermal smelting furnace according to claim 1, characterized in that the central axis cathode electrode (4), the peripheral hollow cathode electrode (5), the furnace shell (7), and the furnace lining (8) It is installed coaxially with the anode electrode (10) of the furnace bottom. 3. The layered combined electrode ore-thermal smelting furnace according to claim 1, wherein the distance from the end of the outer hollow cathode electrode (5) to the top of the furnace bottom anode electrode (10) is the central axis cathode electrode (4). 1.0 to 2.0 times the distance from the end of the ) to the upper part of the anode electrode (10) at the furnace bottom. 4. The layered combined electrode ore-thermal smelting furnace according to claim 1, wherein the cross-sectional area of the peripheral hollow cathode electrode (5) is 1.0-1.5 of the cross-sectional area of the central axis cathode electrode (4). times. 5. The layered combined electrode ore-thermal smelting furnace according to claim 1, wherein the absolute value of the voltage loaded to the central axis cathode electrode (4) is the absolute value of the voltage loaded to the peripheral hollow cathode electrode (5). 0.8 to 0.9 times the value. 6 . The layered combined electrode ore-thermal smelting furnace according to claim 1 , wherein the transformer ( 12 ) and the voltmeter ( 15 , 16 ) are respectively connected with a general control computer. 7 . 7. The layered combined electrode submerged thermal smelting furnace according to claim 1, wherein the water pump (17), the water inlet thermocouple (18) and the water outlet thermocouple (18-1) are respectively associated with the total connected to the control computer. 8 . The layered combined electrode ore-thermal smelting furnace according to claim 1 , wherein the power source ( 11 ) is a DC power source or an AC power source. 9 . 9. The control method of the layered combined electrode ore-thermal smelting furnace according to claim 1, is characterized in that: 1) First, the motor crawler device (13) is controlled by the general control computer (14) to drive the peripheral hollow cathode electrode (5) and the central axis cathode electrode (4) to be inserted into the furnace lining (8); 2) Add raw ore until the charge completely covers the end of the peripheral hollow cathode electrode (5); 3) Drive the cooling water into the furnace shell (7) and furnace body support (9) through the water pump (17), and observe the values on the water inlet thermocouple (18) and the water outlet thermocouple (18-1). When the set temperature is exceeded, the water pump (17) is adjusted by the total control computer (14) to increase the cooling water flow; 3) Turn on the power supply (11) and adjust the transformer (12) so that the voltage value U1 of the first voltmeter (15) is 0.8-0.9 times the voltage value U2 _of the _second voltmeter (16); 4) During the smelting process, both U ₁ and U ₂ will fluctuate. At this time, the transformer (12) is adjusted through the master control computer (14) to maintain the relationship of U ₁ =(0.8～0.9)U ₂ ; 5) When the smelting is completed, first turn off the power supply (11), and then control the motor crawler device (13) through the general control computer (14) to drive the peripheral hollow cathode electrode (5) and the central axis cathode electrode (4) to leave the furnace lining (8) ), and then open the discharge port on the furnace shell (7) to discharge the liquid ore and slag. 10. The method for controlling a layered combined electrode submerged thermal smelting furnace according to claim 9, wherein the raw material ore is iron ore, chromium ore, manganese ore, silica, ferrosilicon, scrap iron, calcium oxide or carbonaceous reducing agents.

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