A safe and controllable electric arc tin smelting furnace

Abstract

A safe and controllable electric arc tin smelting furnace comprises a furnace body, an electrode arm, an electrode rod, a column, a hoist and an automatic control system; the automatic control system comprises an arc detection element and a PLC signal processing system; the solid material smelting working current set in the PLC signal processing system is 5000 amperes; the automatic control system also comprises a collapse pre-detection system and a protection system. The present invention ensures safety, environmental protection and energy saving, is easy to operate, has high reliability and high sensitivity of the automatic control system from multiple perspectives.

Description

Technical Field

[0001] The invention relates to the field of electric arc smelting furnaces, and in particular to a safe and controllable electric arc tin smelting furnace. Background Art

[0002] At present, the winch type electrode adjustment is basically manual. During smelting, a full-time operator needs to manually operate the winch forward and reverse according to the current of each electrode in the furnace to control the electrode lifting position to achieve the purpose of adjusting power. This method has poor stability and slow response. It can only lift a single electrode, which is inconvenient to operate and occupies human resources. In addition, it is not easy to detect whether the electrode rod is at the bottom or top of the furnace during manual operation. Improper operation can easily cause safety problems such as burning of the motor. In addition, it is impossible to detect or predict the collapse of the furnace in time. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a safe and controllable electric arc tin smelting furnace, comprising a furnace body, an electrode arm, an electrode rod, a column, a winch and an automatic control system;

[0004] The electrode arm is arranged on the column in the horizontal direction and is provided with a pulley and a clamping device;

[0005] The electrode rod is vertically arranged on the electrode arm through a clamping device and inserted into the furnace body;

[0006] The winch includes a frequency converter, a motor and a reducer; the speed of the winch is 0~970r / min; the winch is connected to the electrode arm through a wire rope, and the winch drives the electrode rod up and down through the transmission method of reducer-wire rope-pulley-clamping device.

[0007] The automatic control system includes arc detection elements and PLC signal processing system; the arc detection elements include arc current and arc voltage high-precision detection elements evenly distributed inside the furnace body; the solid material smelting working current set in the automatic control system is 5000 amperes; the maximum electrode lifting speed of the automatic control system is 2~4.5m / min; the current adjustment range of the automatic control system is 25~130%I H (Transformer rated current).

[0008] The automatic control system also includes a protection system, which includes an induction coil device arranged at the bottom of the electrode rod and the corresponding position of the furnace body, and also includes a circuit induction device arranged on the motor. The protection functions realized by the protection system include: automatic shutdown when the electrode reaches the top, automatic shutdown when the electrode reaches the bottom, automatic shutdown when the furnace charge is not conductive, automatic shutdown and automatic recovery in one direction (downward) with delayed delay when the electrode is not long enough, and automatic shutdown when the motor is out of phase.

[0009] The automatic control system also includes a material collapse pre-detection system, which is arranged between the arc detection element and the PLC signal processing system; the material collapse pre-detection system monitors the step-wise changing current and voltage received by the arc detection element.

[0010] Furthermore, the automated control system also includes a material collapse pre-detection system, which is arranged between the arc detection element and the PLC signal processing system; the material collapse pre-detection system monitors the step-wise changes in current and voltage received by the arc detection element. Principle of the material collapse pre-detection system: When the material collapses in the furnace, the current conducted by the electrode rod received by the remaining solid material increases relatively, causing the current to increase sharply. The arc detection system detects the drastic current change signal of the solid material and sends a signal to the material collapse pre-detection system. After the material collapse pre-detection system determines that the material collapse conditions are met, it immediately sends an emergency processing signal to the PCL signal processing system, and each system makes corresponding emergency processing.

[0011] Furthermore, the PLC signal processing system receives input signals from arc detection elements, material collapse pre-detection systems, protection systems, etc., and the input signals include: current, voltage level, protection signals and other switching quantities.

[0012] Furthermore, the PLC signal processing system outputs signals to the frequency converter of the winch, and the output signals include: lifting signal, frequency signal, and shutdown signal.

[0013] Furthermore, the inverter of the winch controls the speed and direction of the motor and reducer based on the output signal received from the PCL signal processing system, and further controls the lifting direction and lifting speed of the electrode rod through the wire rope.

[0014] Furthermore, the motor of the winch is a horizontal motor, the reducer of the winch is a turbine reducer, and the wire rope is a drum wire rope.

[0015] Furthermore, rolling bearings are used at the rotating parts of the columns.

[0016] Furthermore, the protection system also includes a tension detector arranged on the wire rope. Once the PCL signal processing system receives a signal from the tension detector showing a drastic fluctuation, the operation of the electrode rod is immediately stopped (it can only run in the reverse direction) and an audible and visual warning is issued.

[0017] Beneficial effects of the present invention:

[0018] The invention provides a safe and controllable electric arc tin smelting furnace, which is highly safe, environmentally friendly and energy-saving, easy to operate, highly reliable, and has a highly sensitive automatic control system. While being able to manually and automatically control the lifting and lowering of electrodes and maintain the stability of smelting current, it also has a material collapse pre-detection function and a protection function. When material collapse just begins to form, it is detected and corresponding measures are taken: first, the electrode rod is quickly raised by starting in advance; second, the maximum automatic lifting speed is much faster than that of an ordinary control system manufactured according to professional standards, and the time for the electrode to separate from the charge is short; third, the reaction is timely, and when the material collapse is about to end and the short-circuit current drops, the high speed is released in time and the arc will not be broken; in this way, the high-voltage switch can be effectively prevented from tripping and the charge from interrupting the electrode, thereby protecting the transformer power supply system and ensuring the safety of the power grid; a reliable protection system for the motor and the electrode is also designed to solve the problem of burning the motor from five protection links; finally, the tension of the wire rope is detected, and the operation of the electrode is stopped once the tension is abnormal. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A plan view of a safe and controllable electric arc tin smelting furnace provided by the present invention;

[0020] Figure 2 A plan view of a safe and controllable electric arc tin smelting furnace provided by the present invention;

[0021] Figure 3 It is a flow chart of the working principle of the automatic control system of the present invention;

[0022] Description of the drawings: 1. winch; 2. wire rope; 3. column; 4. electrode arm; 5. furnace body; 6. cable; 7. transformer; 8. short net. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with the embodiments and drawings.

[0024] Example

[0025] A safe and controllable electric arc tin smelting furnace, comprising a furnace body, an electrode arm, an electrode rod, a column, a winch and an automatic control system;

[0026] The electrode arm is arranged on the column in the horizontal direction and is provided with a pulley and a clamping device;

[0027] The electrode rod is vertically arranged on the electrode arm through a clamping device and inserted into the furnace body; the current is transmitted from the transformer to the electrode rod via the network and cable, and the electrode rod then contacts the solid material in the furnace body. According to the thermal effect of the current, the current does work when passing through the high-resistance solid material, generating heat, which heats up the solid material and melts it into liquid material before reacting; the liquid material no longer needs the electrode rod to be energized, and the electrode rod needs to be lifted away from the liquid material; the reaction product is discharged from the discharge port set under the furnace body;

[0028] The winch includes a frequency converter, a motor and a reducer; the speed of the winch is 0~970r / min; the winch is connected to the electrode arm through a wire rope, and the winch drives the electrode rod up and down through the transmission method of reducer-wire rope-pulley-clamping device.

[0029] The automatic control system includes arc detection elements and PLC signal processing system; the arc detection elements include arc current and arc voltage high-precision detection elements evenly distributed inside the furnace body; the solid material smelting working current set in the automatic control system is 5000 amperes; the maximum electrode lifting speed of the automatic control system is 2~4.5m / min; the current adjustment range of the automatic control system is 25~130%I H (Transformer rated current).

[0030] The automatic control system also includes a protection system, which includes an induction coil device arranged at the bottom of the electrode rod and the corresponding position of the furnace body, and also includes a circuit induction device arranged on the motor. The protection functions realized by the protection system include: automatic shutdown when the electrode reaches the top, automatic shutdown when the electrode reaches the bottom, automatic shutdown when the furnace charge is not conductive, automatic shutdown and automatic recovery in one direction (downward) with delayed delay when the electrode is not long enough, and automatic shutdown when the motor is out of phase.

[0031] The automatic control system also includes a material collapse pre-detection system, which is arranged between the arc detection element and the PLC signal processing system; the material collapse pre-detection system monitors the step-wise changes in current and voltage received by the arc detection element. Working principle of the material collapse pre-detection system: During the smelting process, due to the collapse of the material in the furnace, the current conducted by the electrode rod received by the remaining solid material increases relatively, resulting in a sudden increase in current and a short circuit. The arc detection system detects the drastic change signal of the current of the solid material and sends an emergency signal to the material collapse pre-detection system. After the material collapse pre-detection system determines that the material collapse conditions are met, it immediately sends an emergency processing signal to the PLC signal processing system, and the PLC signal system sends the fastest lifting signal. When the material collapse is about to end, the short-circuit current drops and the high speed is contacted in time, and the arc will not be broken; this can effectively avoid the high-voltage switch tripping and the furnace charge breaking the electrode, protecting the transformer power supply system and ensuring the safety of the power grid.

[0032] The PLC signal processing system receives input signals from arc detection elements, material collapse pre-detection systems, protection systems, etc. The input signals include: current, voltage level, protection signals and other switching quantities.

[0033] The PLC signal processing system outputs signals to the frequency converter of the winch. The output signals include: lifting signal, frequency signal, and shutdown signal.

[0034] The inverter of the winch receives the output signal of the PCL signal processing system, and the inverter controls the speed and direction of the motor and the reducer, and further controls the lifting direction and lifting speed of the electrode rod through the wire rope.

[0035] The motor of the winch is a horizontal motor, the reducer of the winch is a turbine reducer, and the wire rope is a drum wire rope.

[0036] The rotating part of the column adopts rolling bearings.

[0037] The working conditions of the control system are: altitude not exceeding 1000 meters, ambient temperature not exceeding 40 degrees Celsius, and relative humidity not exceeding 85%.

[0038] Finally, the protection system also includes a tension detector installed on the wire rope. Once the PCL signal processing system receives a signal from the tension detector showing a drastic fluctuation, the operation of the electrode rod will be stopped immediately (it can only run in the reverse direction) and an audible and visual warning will be issued.

[0039] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. A safe and controllable electric arc tin smelting furnace, characterized in that: It includes furnace body, electrode arm, electrode rod, column, winch and automatic control system; The electrode arm is arranged on the column in the horizontal direction and is provided with a pulley and a clamping device; The electrode rod is vertically arranged on the electrode arm through a clamping device and inserted into the furnace body; The hoist includes a frequency converter, a motor and a reducer; the speed of the hoist is 0-970r / min; the hoist is connected to the electrode arm through a steel wire rope, and the hoist drives the electrode rod up and down through the transmission mode of reducer-steel wire rope-pulley-clamping device; The automatic control system includes arc detection elements and a PLC signal processing system; the arc detection elements include arc current and arc voltage high-precision detection elements uniformly distributed throughout the furnace body; the solid material smelting working current set in the automatic control system is 5000 amperes; the maximum electrode lifting speed of the automatic control system is 2 to 4.5 m / min; the current adjustment range of the automatic control system is 25 to 130% I H , I H Indicates the rated current of the transformer; The automatic control system further comprises a protection system, which comprises an induction coil device arranged at the bottom of the electrode rod and at the corresponding position of the furnace body, and also comprises a circuit induction device arranged on the motor; The rotating part of the column adopts rolling bearing; The protection system also includes a tension detector arranged on the steel wire rope.

2. A safe and controllable electric arc tin smelting furnace according to claim 1, characterized in that: The automatic control system also includes a material collapse pre-detection system, which is arranged between the arc detection element and the PLC signal processing system; the material collapse pre-detection system monitors the step-wise changing current and voltage received by the arc detection element.

3. A safe and controllable electric arc tin smelting furnace according to claim 2, characterized in that: The PLC signal processing system receives input signals from arc detection elements, material collapse pre-detection systems, protection systems, etc. The input signals include: current, voltage levels, protection signals and other switching quantities.

4. A safe and controllable electric arc tin smelting furnace according to claim 3, characterized in that: The PLC signal processing system outputs signals to the frequency converter of the winch, and the output signals include: lifting signal, frequency signal, and shutdown signal.

5. A safe and controllable electric arc tin smelting furnace according to claim 4, characterized in that: The inverter of the hoist receives the output signal of the PLC signal processing system, and the inverter controls the speed and direction of the motor and reducer, and further controls the lifting direction and lifting speed of the electrode rod through the wire rope.

6. A safe and controllable electric arc tin smelting furnace according to claim 1, characterized in that: The motor of the hoist is a horizontal motor, the reducer of the hoist is a turbine reducer, and the steel wire rope is a drum steel wire rope.

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