Open type electric arc furnace for researching steel slag melting

Abstract

The invention discloses an open electric arc furnace for researching steel slag melting, which comprises an arcing device, a heating platform, a temperature monitoring device, an electric welding machine and a bracket, and a graphite rod and a graphite plate are used as arcing materials to melt steel slag laid above the graphite plate. In the arcing device, an electromagnet is used for controlling lifting of a graphite rod, and a time relay is used for controlling power-on and power-off of the electromagnet. In the heating platform, an iron plate is used for conducting current to a graphite plate, a thermocouple is installed below the iron plate to monitor temperature distribution of the heating platform, and a corundum plate and heat insulation cotton are used for protecting the thermocouple. The lifting platform is used in the heating platform and used for adjusting the distance between the graphite rod and the graphite plate, so that a good arcing effect is achieved. An electric welding machine is used as a power supply to supply power to the graphite rod and the graphite plate. An electromagnet, a graphite sliding rail and a heating platform are fixed through a support. The electric arc furnace is high in temperature upper limit, high in temperature rising speed and capable of rapidly heating steel slag to be in a complete melting state.

Description

TECHNICAL FIELD

[0001] The present application relates to an arc furnace experimental device using graphite as positive and negative electrodes, in particular to an open arc furnace experimental device for studying the melting of steel slag in a ladle furnace. BACKGROUND

[0002] Ladle refining is an essential process in the production process of modern steel industry. The ladle furnace has become one of the most widely used secondary refining equipment due to its relatively simple structure, low investment cost, flexible operation and significant refining effect. During the process of refining liquid steel in the ladle furnace, an electrode is used to generate an arc with the steel slag covering the upper layer of the liquid steel, and a large amount of heat generated by the arc is conducted through the steel slag to heat the liquid steel, so that the liquid steel reaches the target temperature before continuous casting. Therefore, the melting performance of the steel slag is an important factor affecting the temperature rise of the liquid steel, and the melting time directly affects the length of the entire refining process.

[0003] The composition, thickness, and arc temperature of the steel slag will affect the melting speed of the steel slag. The main components of the steel slag are calcium oxide, silicon oxide, aluminum oxide, and magnesium oxide, and the liquidus temperature can reach more than 2000℃. The existing electric heating furnace uses resistance wires as a heat source, which has low requirements for the type of heated samples and can heat the steel slag, but has the problem of slow heating speed and low upper limit of temperature, which cannot meet the requirements. The existing high-frequency induction furnace generates a high-frequency electromagnetic field through an oscillation circuit to make the sample generate eddy current heating and melting, which has a high upper limit of temperature, but requires the heated sample to be a conductor, which cannot heat the steel slag. To solve this problem, an electric welding machine is used as a power supply device, an arc is used as a heat source, and an open arc furnace is designed, which can heat the steel slag to a completely melted state and has a fast heating speed, meeting the experimental requirements. SUMMARY

[0004] The purpose of the present application is to provide an open arc furnace for studying the melting of steel slag, which combines the heating principle of the ladle furnace and the industrial welding principle, and reduces the electrode heating part of the ladle furnace in structure. When used, the arc is melted by the arc striking device and the heating platform. The arc striking behavior and the arc striking time can be precisely controlled, and the temperature distribution of the steel slag melting process can be monitored.

[0005] To achieve stable arc striking, an electric welding machine (14) is used as a power supply device, which has the characteristics of stable arc striking and adjustable voltage and current. The two output ends of the electric welding machine (14) are connected to the graphite slide rail (6) of the arc striking device and the iron plate (9) of the heating platform through welding machine special lines, respectively.

[0006] In order to realize the precise control of the arc starting behavior and the arc starting time, the time relay (1) and the electromagnet (2) are used as the control part of the arc starting device, the electromagnet (2) is connected with the graphite rod (5) through the coupling (3), and the insulating rod (4) is added in the middle to insulate the electromagnet (2) and the graphite rod (5), so that the effect of precise control of the arc starting behavior is achieved; the electromagnet (2) is connected with the time relay (1), so that the effect of precise control of the power-on and power-off time of the electromagnet (2) is achieved.

[0007] In order to increase the service life and ensure the cleaning of the steel slag in the slag melting process, the graphite with high melting point and good conductivity is selected as the arc starting material, the graphite rod (5) is inserted through the graphite slide rail (6), the graphite plate (8) is placed above the iron plate (9), and the steel slag (7) to be melted is evenly laid on the graphite plate (8). During the experiment, the electromagnet (2) is powered on by the time relay (1), the graphite rod (5) is pushed to move downward to approach the graphite plate (8), a loop is formed between the electric welding machine (14), the graphite slide rail (6), the graphite rod (5), the thin layer of air between the graphite rod (5) and the graphite plate (8), the graphite plate (8), and the iron plate (9), the thin layer of air is broken down, and the arc is generated to melt the steel slag (7).

[0008] In order to realize the monitoring of the temperature distribution of the steel slag (7) melting process, a temperature monitoring device is designed, a thermocouple (11) is used for temperature measurement, the measured temperature data is transmitted to the temperature monitor (12) and stored in the computer (13). In order to avoid the damage of the high temperature arc to the thermocouple (11), the thermocouple (11) is installed below the heating platform, in order to prevent the current of the iron plate (9) from interfering with the thermocouple (11), a corundum plate (10) with insulation and high temperature resistance is installed between the iron plate (9) and the thermocouple (11), in order to reduce the temperature measurement error, the thermal conductive silicone grease is evenly applied between the iron plate (9) and the corundum plate (10) and between the corundum plate (10) and the thermocouple (11), and the heat insulation cotton (15) is pasted below the corundum plate (10). A plurality of thermocouples (11) are arranged in a horizontal straight line below the corundum plate (10), and the spacing between the plurality of thermocouples (11) is adjusted according to the experimental requirements.

[0009] In order to precisely adjust the distance between the graphite rod (5) and the graphite plate (8) and achieve good arc starting effect, a lifting platform (16) is installed below the heating platform.

[0010] In order to ensure that the relative position of the arc starting device and the heating platform is fixed, a support (17) is designed to fix the electromagnet (2) and the graphite slide rail (6), and the lifting platform (16) is placed on the base of the support (17).

[0011] In order to ensure the smooth progress of the experiment and obtain the best experimental results, the electromagnet (2) push rod, coupling (3), insulating rod (4), graphite rod (5), graphite slide rail (6) are installed on the same axis, the connection between graphite rod (5) and graphite slide rail (6) is sliding connection, graphite rod (5) is always in contact with graphite slide rail (6) under the drive of electromagnet (2). Adjust the position of the heating platform, so that any one of the two ends of the plurality of thermocouples (11) arranged in a straight line is on the axis of the graphite rod (5) of the arc striking device, so that the plurality of thermocouples (11) in the temperature monitoring device measure the temperature of the surrounding area centered on the arc. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is a whole structure diagram of the open electric arc furnace for studying steel slag melting.

[0013] Figure 2 It is a structure diagram of the arc striking device, heating platform, thermocouple (11) and support (17) of the open electric arc furnace for studying steel slag melting.

[0014] Figure 3 It is a structure diagram of the arc striking device, heating platform and support (17) of the open electric arc furnace for studying steel slag melting.

[0015] In the figure: 1. Time relay; 2. Electromagnet; 3. Coupling; 4. Insulating rod; 5. Graphite rod; 6. Graphite slide rail; 7. Steel slag; 8. Graphite plate; 9. Iron plate; 10. Corundum plate; 11. Thermocouple; 12. Temperature monitor; 13. Computer; 14. Electric welder; 15. Heat insulation cotton; 16. Lifting platform; 17. Support. DETAILED DESCRIPTION

[0016] This part will describe the specific implementation of the present application in detail, the preferred embodiment of the present application is shown in the attached drawings, the role of the drawings is to supplement the description of the text part with graphics, so that people can intuitively and visually understand each technical feature and the overall technical solution of the present application, but it cannot be understood as a limitation on the protection scope of the present application.

[0017] When using the open electric arc furnace for studying steel slag melting, the measures of smoke exhaust, fire prevention, electric shock prevention and strong light prevention must be taken first, refer to Figure 2, first put the support (17) on a stable platform, and place the lifting platform (16) on the base of the support (17). Arrange multiple thermocouples (11) in a straight line, adjust the spacing according to experimental requirements, and fix them below the corundum plate (10). Apply heat-conducting silicone grease evenly on both sides of the corundum plate (10), tightly attach the upper surface to the iron plate (9), and the lower surface to the heat insulation cotton (15). Place the corundum plate (10) horizontally on the lifting platform (16). Connect the thermocouples (11) with the temperature monitor (12), and adjust the temperature monitor (12) to accurately receive temperature data and transmit it to the computer (13).

[0018] Referring to Figure 1 Fix the electromagnet (2) at the top of the support (17), and use two couplings (3) to sequentially fix the electromagnet (2) push rod, insulating rod (4), and graphite rod (5). Fix the graphite slide rail (6) on the support (17), and take good insulation measures between the two. Pass the graphite rod (5) through the graphite slide rail (6). Adjust the positions of the above components to be on the same axis, and ensure that the graphite rod (5) always maintains contact with the graphite slide rail (6) under the drive of the electromagnet (2). Adjust the position of the heating platform so that any one of the two ends of the multiple thermocouples (11) arranged in a straight line is on the axis of the graphite rod (5) of the arc striking device. Connect the electromagnet (2) with the time relay (1), and supply power to the electromagnet (2) and the time relay (1).

[0019] Connect the two output ends of the electric welding machine (14) with the graphite slide rail (6) of the arc striking device and the iron plate (9) of the heating platform, respectively, through welding machine special lines.

[0020] Place the steel slag (7) evenly on the graphite plate (8), and place the graphite plate (8) on the heating platform iron plate (9). Adjust the height of the lifting platform (16) to a small gap between the lowest position of the graphite rod (5) and the graphite plate (8). Turn on the power of the electric welding machine (14), adjust the voltage and current parameters to appropriate values, and adjust the temperature monitor (12) to start recording temperature data. Turn on the power of the time relay (1) and the electromagnet (2), input the required power-on time into the time relay (1), and make it run to automatically connect the power supply circuit of the electromagnet (2) to drive the graphite rod (5) to move downward, break through the thin layer of air between the graphite plate (8), generate an electric arc, and start the melting period. After the time relay (1) finishes counting, it automatically disconnects the power supply circuit of the electromagnet (2) to drive the graphite rod (5) to move upward and extinguish the electric arc, ending the melting period. After the temperature of the heating platform drops to room temperature, save the temperature data, cut off the power of the time relay (1), the electromagnet (2), and the electric welding machine (14), and collect the molten steel slag sample for subsequent research.

Claims

1. An open electric arc furnace for studying steel slag melting, comprising an arc starting device, a heating platform, a temperature monitoring device, an electric welding machine (14), a support (17), characterized in that: the arc starting device comprises a time relay (1), an electromagnet (2), a coupling (3), an insulating rod (4), a graphite rod (5), and a graphite slide rail (6), the time relay (1) is connected with the electromagnet (2) to control the time of energization and de-energization of the electromagnet (2), two couplings (3) are used to connect the electromagnet (2) push rod, the insulating rod (4), and the graphite rod (5), so that the electromagnet (2) can control the lifting of the graphite rod (5), and the electromagnet (2) and the graphite rod (5) are insulated through the insulating rod (4), the graphite rod (5) passes through the graphite slide rail (6) to form a sliding connection; the heating platform comprises a steel slag (7), a graphite plate (8), an iron plate (9), a corundum plate (10), heat insulation cotton (15), and a lifting platform (16), the graphite plate (8) bearing the steel slag (7) is connected with the electric welding machine (14) through the iron plate (9), the corundum plate is used to insulate the current of the iron plate (9) to protect multiple thermocouples (11) in the temperature monitoring device, the heat insulation cotton (15) improves the temperature measurement accuracy of the temperature monitoring device, and the lifting platform (16) can accurately adjust the distance between the graphite rod (5) and the graphite plate (8) to achieve good arc starting effect; the temperature monitoring device comprises the thermocouples (11), a temperature monitor (12), and a computer (13), multiple thermocouples (11) are arranged below the corundum plate (10) and connected with the temperature monitor (12) to collect temperature data and store the temperature data to the computer (13); the electric welding machine (14) is used to supply power to the arc starting device and the heating platform, two output ends of the electric welding machine (14) are connected with the graphite slide rail (6) and the iron plate (9) through welding machine special lines respectively to supply power to the graphite rod (5) and the graphite plate (8), and the electric welding machine (14) is used to supply power to the graphite rod (5) and the graphite plate (8) to break through the thin layer of air between them to generate an electric arc to heat the steel slag (7); the support (17) is used to fix the electromagnet (2) and the graphite slide rail (6) and support the lifting platform (16) to fix the relative position of the arc starting device and the heating platform.

2. An arcing device and heating platform for use in an open-arc furnace for studying steel slag melting according to claim 1, characterized in that: When the time relay (1) controls the energization of the electromagnet (2), the electromagnet (2) push rod is pushed out to drive the graphite rod (5) to move downward through the coupling (3) and the insulating rod (4) to approach the graphite plate (8) to break through the thin layer of air to generate an electric arc, when the time relay (1) controls the de-energization of the electromagnet (2), the electromagnet (2) push rod is retracted to drive the graphite rod (5) to move upward through the coupling (3) and the insulating rod (4) to move away from the graphite plate (8) to extinguish the electric arc.

3. An arcing device and support (17) for use in an open-arc furnace for the study of steel slag melting according to claim 1 or 2, characterized in that: The graphite rod (5) is driven by the electromagnet (2) to move along the axis in the graphite slide rail (6), the connection between the electromagnet (2), the push rod, the coupling (3), the insulating rod (4) and the graphite rod (5) is a fastening connection, the connection between the electromagnet (2) and the support (17) is a fastening connection, the connection between the graphite slide rail (6) and the support (17) is a fastening connection, the connection between the graphite rod (5) and the graphite slide rail (6) is a sliding connection, and the graphite rod (5) is always in contact with the graphite slide rail (6) under the driving of the electromagnet (2).

4. A heating platform and temperature monitoring device for use in an open-arc furnace for studying steel slag melting according to claim 1 or 2, characterized in that: A plurality of thermocouples (11) are fixed below the heating platform corundum plate (10) and arranged in a straight line, the distance between the plurality of thermocouples (11) is adjusted according to requirements, and heat-conducting silicone grease is evenly applied between the thermocouples (11) and the corundum plate (10).

5. An arc starting device, heating platform, temperature monitoring device for use in an open-arc furnace for studying steel slag melting according to claims 1-4, characterized in that: The heating platform is in a horizontal state, the steel slag (7) is evenly laid on the graphite plate (8), the graphite plate (8) is placed on the iron plate (9), heat-conducting silicone grease is evenly applied and fixed between the iron plate (9) and the corundum plate (10), heat insulation cotton (15) is pasted below the corundum plate (10), and the thermocouple (11) at one end of the heating platform is adjusted to be in the same vertical direction as the graphite rod (5) of the arc striking device.

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