Aluminum electrolytic cell shelling cylinder pressure signal acquisition device and method

Abstract

The present invention discloses a device and method for collecting pressure signals from a shelling cylinder in an aluminum electrolytic cell. The device comprises a microprocessor unit, a signal overvoltage protection and collection unit, a CAN bus interface, an intelligent high-side power switch, and wiring terminals. The wiring terminals are connected to an AD sampling port of the microprocessor unit via an overvoltage protection and collection circuit. The microprocessor unit is connected to a CAN bus interface, which is connected to a cell controller. The wiring terminals are connected to a pressure sensor, which is powered by an intelligent high-side power switch, which is connected to the microprocessor unit. The device effectively solves the circuit protection problem of prolonged signal overcurrent, which can occur when the sensor power line and signal line are short-circuited due to the harsh environment in the electrolytic cell. Furthermore, the device can provide intelligent control and alarm functions.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum electrolytic cell shelling cylinder pressure monitoring equipment, and relates to an aluminum electrolytic cell shelling cylinder pressure signal acquisition device and method. Background Art

[0002] With the continuous development of intelligent manufacturing in the aluminum industry, the existing shell-breaking and feeding system can no longer meet the energy-saving and consumption-reducing needs of electrolytic cells. First, the existing shell-breaking and feeding system cannot intelligently identify blockages, which can easily lead to uneven local alumina concentration, frequent anode effects, increased power consumption, and reduced current efficiency. Second, the existing shell-breaking and feeding system cannot control the action time of the shell-breaking hammer head according to the unobstructed condition of the feeding point, resulting in a lot of unnecessary shell-breaking, increased wear on the hammer head and cylinder, and wasted compressed air. It can also easily cause electrolyte to adhere to the hammer head, resulting in uneven local alumina concentration. In addition, when the existing shell-breaking and feeding system encounters a blockage problem, it requires manual inspection and processing, which is labor-intensive and can cause significant interference to the electrolytic cell.

[0003] To address this issue, the pressure change in the cylinder intake pipe during the shelling process is monitored to determine if the hole has been penetrated. Based on the working principle of the cylinder, theoretically, the corresponding pressure changes for a penetration and a blockage are different. A pressure sensor is used to detect the pressure change during shelling to identify whether the hole has been penetrated. Based on this, the shelling and unloading system can be intelligently controlled. A pressure sensor is installed in the intake pipe of each shelling cylinder. This sensor converts the pressure signal into a 4-20mA signal that is fed to the data acquisition board. This sensor uses a two-wire system: a power line and a signal line. Due to the harsh environment of the electrolytic cell, high temperatures, dust, and strong magnetic fields can easily damage the sensor wires, connectors, or internal circuitry, leading to a short circuit between the power line and the signal line. This short circuit can easily damage the pressure signal acquisition board. Conventional practice is to add a resettable fuse to the sampling circuit, connected in series with the sampling resistor. However, the current signal sampling resistor generally has a small resistance value, but requires high accuracy. When the sensor power line and signal line are short-circuited, it will be in an overcurrent state for a long time. The self-recovery insurance action requires a certain amount of heat. If the sampling resistor has a small power, it will be easily damaged. In this case, a larger power sampling resistor is required. However, due to the requirements for the sampling resistor's accuracy and size, it will cause great difficulties in the selection of the resistor. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a device and method for collecting pressure signals of a shelling cylinder of an aluminum electrolytic cell, so as to solve the problems existing in the prior art.

[0005] The technical solution adopted by the present invention is: a pressure signal acquisition device for the shelling cylinder of an aluminum electrolytic cell, including a microprocessor unit, a signal overvoltage protection and acquisition unit, a CAN bus interface, an intelligent high-side power switch and a terminal block. The terminal block is connected to the AD sampling port of the microprocessor unit through an overvoltage protection and acquisition circuit. The microprocessor unit is connected to the CAN bus interface, the CAN bus interface is connected to the cell control machine, the terminal block is connected to the pressure sensor, and the pressure sensor is powered by the intelligent high-side power switch. The intelligent high-side power switch is connected to the microprocessor unit.

[0006] Preferably, the intelligent high-side power switch uses a dual-channel intelligent high-side power switch, and every five pressure sensors use one channel.

[0007] Preferably, the above-mentioned microprocessor unit adopts an STM32 processor.

[0008] Preferably, the microprocessor unit is provided with at least 10 AD sampling ports.

[0009] A method for collecting pressure signals from a shelling cylinder of an aluminum electrolytic cell is disclosed. The method comprises the following steps: a microprocessor unit detects whether a 4-20 mA signal is normal; when the monitored current signal is greater than or equal to 25 mA, the microprocessor sends a signal to control an intelligent high-side power switch, cutting off the power supply to the pressure sensor, performing overcurrent protection and issuing an alarm; and then performing a self-check every minute to detect whether the signal has returned to normal.

[0010] Beneficial effects of the present invention: Compared with the prior art, the present invention uses an intelligent high-side power switch to power the pressure sensor, and the microprocessor unit detects whether the 4~20mA signal is normal. When the current signal is monitored to be greater than or equal to 25mA, the microprocessor sends a signal to control the intelligent high-side power switch, cuts off the power supply of the pressure sensor, performs overcurrent protection and alarm, and then self-checks every minute to detect whether the signal has returned to normal. This design effectively solves the circuit protection problem of long-term overcurrent of the signal caused by the harsh environment on the electrolytic cell, which easily leads to a short circuit between the sensor power line and the signal line, and can also intelligently control and alarm. Therefore, compared with the existing aluminum electrolytic cell shelling cylinder pressure signal acquisition device, the present invention has the advantages of simple structure, high intelligence, low cost, and reliable operation. The present invention is particularly suitable for real-time acquisition of aluminum electrolytic cell shelling cylinder pressure signals in harsh on-site environments such as high temperature, dust, strong magnetic field, and corrosiveness, and has certain advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the functional zoning of the present invention;

[0012] Figure 2 Schematic diagram of system connection of the present invention. DETAILED DESCRIPTION

[0013] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0014] Example 1: Figure 1-2 As shown, a pressure signal acquisition device for the shelling cylinder of an aluminum electrolytic cell based on the overcurrent protection technology of an intelligent high-side power switch includes a microprocessor unit 1, a signal overvoltage protection and acquisition unit 2, an intelligent high-side power switch 4, a CAN bus interface 3 and a terminal 5. The terminal 5 is connected to the AD sampling port of the microprocessor unit 1 through the signal overvoltage protection and acquisition unit 2. The microprocessor unit 1 is connected to the CAN bus interface 3 and is provided with at least 10 AD sampling ports. The CAN bus interface 3 is connected to the cell control machine 6. The terminal is connected to the pressure sensor 8. The pressure sensor is used to detect the pressure change of the cylinder intake pipe during the shelling process. The power supply of the pressure sensor 8 is supplied by the intelligent high-side power switch 4. The intelligent high-side power switch 4 is connected to the microprocessor unit 1. The intelligent high-side power switch 4 uses a dual-channel intelligent high-side power switch 4, and there are 5 of them. The pressure sensor 8 uses one channel. The processor 1 uses the chip model STM32F103, the intelligent high-side power switch 4 uses the chip model BTS723GW, and the CAN bus 3 driver chip model is 82C250. In view of the special environment of aluminum electrolysis, the CAN bus interface 3 on the acquisition board is connected to the external CAN bus for optical isolation.

[0015] The present invention cleverly utilizes an intelligent high-side power switch 4 in an aluminum electrolytic cell shelling cylinder pressure signal acquisition device. Ten 4-20 mA current signals are connected to an acquisition board via plug-in terminals 5, then pass through a signal overvoltage protection and acquisition circuit 2, and finally to the AD sampling port of an STM32 processor 1. The intelligent high-side power switch 4 supplies power to a pressure sensor 8. A microprocessor unit 1 detects whether the 4-20 mA signal is normal. When the current signal is detected to be greater than or equal to 25 mA, the microprocessor 1 sends a signal to the intelligent high-side power switch 4, disconnecting the power supply to the sensor 8, providing overcurrent protection and an alarm. The device then performs a self-test every minute to check whether the signal has returned to normal. The acquisition device 7 communicates with the cell controller 6 via a CAN bus interface 3.

[0016] Example 2: A method for collecting pressure signals of a shelling cylinder pressure signal collection device for an aluminum electrolytic cell, the method being as follows: a microprocessor unit 1 detects whether a 4-20 mA signal is normal. When a current signal is detected to be greater than or equal to 25 mA, the microprocessor 1 sends a signal to control the intelligent high-side power switch 4, cuts off the power supply to the sensor 8, performs overcurrent protection and alarms, and then performs self-checks every minute to detect whether the signal has returned to normal.

[0017] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, which should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A device for collecting pressure signals of a shelling cylinder of an aluminum electrolytic cell, characterized by: The invention comprises a microprocessor unit (1), a signal overvoltage protection and acquisition unit (2), an intelligent high-side power switch (4), a CAN bus interface (3) and a wiring terminal (5), wherein the wiring terminal (5) is connected to an AD sampling port of the microprocessor unit (1) through the signal overvoltage protection and acquisition unit (2), the microprocessor unit (1) is connected to the CAN bus interface (3), the CAN bus interface (3) is connected to a slot control machine (6), the wiring terminal (5) is connected to a pressure sensor (8) and supplies power to the pressure sensor (8) through the intelligent high-side power switch (4), and the intelligent high-side power switch (4) is connected to the microprocessor unit (1).

2. The aluminum electrolysis cell shelling cylinder pressure signal acquisition device according to claim 1, characterized in that: The intelligent high-side power switch (4) uses a dual-channel intelligent high-side power switch (4), and each of the five pressure sensors (8) uses one channel.

3. The aluminum electrolysis cell shelling cylinder pressure signal acquisition device according to claim 2, characterized in that: The microprocessor unit (1) adopts STM32 processor.

4. The aluminum electrolysis cell shelling cylinder pressure signal acquisition device according to claim 1, characterized in that: The microprocessor unit (1) is provided with at least 10 AD sampling ports.

5. The method for collecting pressure signals of a shelling cylinder of an aluminum electrolytic cell according to any one of claims 1 to 4, characterized in that: The method is as follows: a microprocessor unit (1) detects whether a 4-20 mA signal is normal; when the current signal is detected to be greater than or equal to 25 mA, the microprocessor unit (1) sends a signal to control an intelligent high-side power switch (4), cuts off the power supply of a pressure sensor (8), performs overcurrent protection and alarms, and then performs self-test every minute to detect whether the signal has returned to normal.

Images