Manual and Automatic Control System for the Crushing and Screening Production Process of Electrically Fused Magnesia

Abstract

The present invention relates to a manual and automatic control system for the crushing and screening production process of fused magnesia, comprising: a control unit, an actuator connected thereto, and a sensing unit; the actuator includes a first frequency converter and a first motor connected thereto, a second frequency converter and a second motor connected thereto, and a third motor; the first motor is connected to a blanking bin in an electric feeding device; the second motor is connected to a crusher in a crushing device; the third motor is connected to a vibrating screen in an electric vibrating device; the sensing unit includes a vibration amplitude detection device and a vibration return material detection device; the vibration amplitude detection device is arranged on the vibrating screen of the electric vibrating device; the vibration return material detection device is arranged on a material return channel between the vibrating screen and the crusher; the present invention is provided with an emergency stop button and an automatic stop program, which ensure the safety of the production process when abnormal working conditions occur.

Description

Technical Field

[0001] The present invention belongs to the technical field of the production control of fused magnesia, and particularly relates to a manual and automatic control system for the crushing and screening production process of fused magnesia. Background Art

[0002] Fused magnesia has excellent insulation, heat conduction, and high-temperature resistance properties, and its application fields are very extensive. Especially in the production of electric heating components, it has become an essential insulation filling material in household appliances. However, the production of fused magnesia in China generally has the following problems: the processing equipment is relatively old and the degree of automation is low, resulting in low production efficiency, low raw material utilization rate, and poor product consistency. And the crushing and screening process of fused magnesia, as the starting process of the production process, greatly affects the utilization rate of raw materials.

[0003] At present, between the devices in the crushing and screening process of fused magnesia, only the local start and stop of a single device can be realized, and automatic control cannot be achieved according to the parameters in the production process. As a result, the feeding speed before crushing and the screening speed are fixed, and the feeding frequency and screening frequency cannot be automatically adjusted, making the entire process prone to clogging, causing equipment shutdown, and affecting production. Summary of the Invention

[0004] The purpose of the present invention is to provide a manual and automatic control system for the crushing and screening production process of fused magnesia, to realize the local manual control and remote automatic control of the crushing and screening process of fused magnesia, and to improve the crushing and screening efficiency of fused magnesia.

[0005] The technical solution adopted by the present invention to achieve the above purpose is: a manual and automatic control system for the crushing and screening production process of fused magnesia, comprising: a manual-automatic switching control unit, an actuator connected thereto, and a sensing unit;

[0006] The actuator includes a first frequency converter and a first motor connected thereto, a second frequency converter and a second motor connected thereto, and a third motor; the first motor is connected to the feeding bin in the electric feeding device; the second motor is connected to the crusher in the crushing device; the third motor is connected to the vibrating screen in the electric vibrating device;

[0007] The sensing unit includes a vibration amplitude detection device and a vibration return material detection device; the vibration amplitude detection device is arranged on the vibrating screen of the electric vibrating device; the vibration return material detection device is arranged on the material return channel between the vibrating screen and the crusher;

[0008] The first frequency converter, the second frequency converter, the vibration amplitude detection device, and the vibration return material detection device are all connected to the manual-automatic switching control unit.

[0009] An air switch QF, a contactor KM, and a thermal relay FR are sequentially connected between the three-phase power supply and the three-phase input ends of each of the first motor, the second motor, and the third motor.

[0010] The manual-automatic switching control unit includes three control loops, which are respectively connected to the first frequency converter, the second frequency converter, and the third motor;

[0011] The control loop includes a knob switch, a start button SB1, a stop button SB2, and an emergency stop button SB3 that are sequentially connected between any two phases of the three-phase power supply; the start button SB1 is connected to the manual control side output end of the knob switch;

[0012] Three control input ends of the controller are respectively connected to the automatic control side output ends of the knob switches of the three control loops, and three control output ends of the controller are respectively connected to the first frequency converter, the second frequency converter, and the third motor; the controller is connected to the vibration amplitude detection device and the vibration return material detection device.

[0013] The vibration amplitude detection device is an amplitude sensor.

[0014] The vibration return material detection device is a powder flow meter.

[0015] Both ends of the start button SB1 in the control loop are respectively connected to a pair of contacts of the contactor KM to control the start of the motor corresponding to this control loop through the start button SB1.

[0016] The emergency stop button SB3 is connected in series with the contactor KM coil and the thermal relay FR coil to control the stop of its corresponding motor through this control loop.

[0017] The control loop further includes an indicator light connected in series with the emergency stop button SB3.

[0018] A manual-automatic control method for the electrofused magnesia crushing and screening production process includes the following steps:

[0019] The control mode is switched by turning the knob switch SA. When the knob switch SA is connected to the controller, it is the automatic mode; when the knob switch SA is connected to the start button SB1, it is the manual control mode;

[0020] When switched to the automatic mode, according to the detected vibration return material flow rate, vibration screen vibration amplitude, and frequency converter current, the controller controls the first motor and the second motor to respectively control the feeding speed of the feeding bin and the crushing speed of the crusher:

[0021] When the flow rate of the vibrating return material is greater than the preset value, control the second motor to increase the crushing speed of the crusher, and control the first motor to slow down the feeding speed of the feeding bin or stop it; when the flow rate of the return material returns to the normal range, then control the first motor to increase the feeding speed of the feeding bin;

[0022] When the current of the second frequency converter increases within the set time, control the first motor to slow down the feeding speed of the feeding bin or stop feeding until the current of the second frequency converter returns to the normal value, and then control the first motor to increase the feeding speed;

[0023] When switching to the manual control mode, by operating the start button SB1, stop button SB2 and emergency stop button SB3 in different control circuits, the start and stop of the actuator corresponding to the control circuit are realized.

[0024] The present invention has the following beneficial effects and advantages:

[0025] 1. The present invention designs a manual-automatic control system for the crushing and screening link in the production process of fused magnesia. Through the knob switch, two control modes of manual and automatic are realized. And in the automatic control mode, by setting corresponding control circuits for different actuators, the feeding speed and crushing speed in the crushing and screening link can be automatically adjusted by one controller, avoiding situations such as blockage and shutdown, and improving production efficiency.

[0026] 2. The present invention connects contactors and thermal relays in series in the control circuit, which can achieve overload protection for the motor.

[0027] 3. The present invention connects the start button SB1 in parallel with the switch side of the contactor, which can make the motor run in self-locking mode in the manual control mode.

[0028] 4. The present invention can not only realize the remote automatic control of each production equipment, but also realize the local manual control of each equipment. At the same time, the two can be switched without interference, without affecting the current production state, and ensuring the reliability of the production process.

[0029] 5. The present invention is provided with an emergency stop button and an automatic stop program, which ensure the safety of the production process when abnormal working conditions occur. Description of the Drawings

[0030] Figure 1 is a schematic structural diagram of the crushing and screening link in the production process of fused magnesia of the present invention;

[0031] Figure 2 is a schematic structural diagram of the automatic control system of the present invention;

[0032] Figure 3a is the electrical circuit diagram of the motor of the present invention;

[0033] Figure 3b This is the manual and automatic control circuit diagram of the present invention. Detailed implementation manners

[0034] The present invention will be further described in detail below in conjunction with the accompanying drawings and examples.

[0035] 1. As Figure 1 shown, a manual and automatic control system for the electrofused magnesia crushing and screening production process includes the following devices: an electric feeding device, a crushing device, an electric vibration device, and a supporting control cabinet and electrical cabinet. The electric feeding device, the crushing device, and the electric vibration device are all prior arts.

[0036] The electric feeding device includes a feeding bin, a motor, and a supporting electrical cabinet. The feeding bin is used to store raw materials of a specified weight, and the motor vibrates the bin to achieve the purpose of vibrating feeding; a frequency converter is designed in the supporting electrical cabinet to control parameters such as the rotation speed and frequency of the motor.

[0037] The crushing device includes a crusher, a bucket elevator, and a supporting electrical cabinet. The crusher and the bucket elevator are both commonly used equipment in the ore field. The raw materials are crushed by the crusher, and then the bucket elevator transports the crushed materials to the next device; a frequency converter is designed in the supporting electrical cabinet to control parameters such as the rotation speed and frequency of the crusher.

[0038] The electric vibration device includes a vibrating screen, a vibration amplitude detection device, and a vibration return material detection device. The vibrating screen is used to screen the required electrofused magnesia, return materials larger than the specified range to the crusher for continuous crushing, recycle materials smaller than the specified range as waste, and materials within the specified range enter the next process; the vibration amplitude detection device is an amplitude sensor used to detect the current vibration amplitude of the vibrating screen; the vibration return material device is a powder flowmeter, and the flow rate of materials larger than the specified range transmits data to the controller in a remote transmission form.

[0039] The control cabinet includes a controller and supporting weak-current equipment, and communicates with the computer in the remote control room through a network cable; the electrical cabinet includes frequency converters, contactors, thermal relays, etc. supporting the above-mentioned devices.

[0040] 2. As Figure 2 shown, in order to improve the efficiency of electrofused magnesia crushing and screening and the utilization rate of raw materials, an automatic control system is designed to automatically adjust the feeding speed and the crushing speed to ensure the continuous operation of production. Based on the on-site parameters detected, including vibration return material data, the vibration amplitude of the vibrating screen, and the current current of the motor of the crushing device, the controller issues adjustment commands to control the actuators, including the frequency converter of the electric feeding device, the frequency converter of the crushing device, the vibrating screen, etc., to adjust the speed and frequency of each device in the crushing and screening process, achieving the purpose of reducing blockages, avoiding shutdowns, and continuous operation.

[0041] Meanwhile, to ensure production safety, an emergency stop button is designed. When abnormal working conditions occur on-site or the frequency converter malfunctions, etc., the emergency stop operation can be completed and all equipment stops running.

[0042] 3. During the production process, sometimes local control of each equipment is required due to production needs or necessary manual judgment and intervention. During the process of switching between manual and automatic modes, it is particularly important to keep the operating state of the equipment unaffected. To address this issue, the design of this system can achieve seamless switching between automatic remote control and manual local control through the control mode rotary switch on-site. The following explains the entire manual-automatic control system in combination with the circuit diagram:

[0043] As Figure 3a 、 Figure 3b shown in the electrical circuit, each equipment in the fused magnesia crushing and screening section operates through a motor, and each motor is connected in series through an air switch QF, a contactor KM, and a thermal relay FR from a three-phase power supply.

[0044] As Figure 3a 、 Figure 3b shown in the control circuit, two of the three-phase power supplies are taken as the power supply for the control circuit, and the control mode is switched by rotating the control mode conversion rotary switch SA set on-site. When switched to the automatic mode, the operator can control each equipment through a computer in the remote control room. The controller automatically adjusts the feeding speed and crushing speed according to the detected on-site parameters, such as the vibrating return material flow rate, the vibration amplitude of the vibrating screen, the current of the frequency converter, etc. For example: when the vibrating return material flow rate is greater than the preset value, the operating speed of the crushing device is automatically increased, the feeding speed is slowed down or the machine is stopped, and when the return material flow rate returns to normal, the feeding speed is increased again; when the current of the frequency converter of the crushing device suddenly increases, immediately control to slow down the feeding speed or stop feeding, and when the current of the frequency converter of the crushing device returns to the normal value, the feeding speed is increased again. When switched to the manual control mode, the operator can operate the equipment through the on-site electrical cabinet, including operating the start button SB1, stop button SB2, and emergency stop button SB3 of each equipment. At the same time, the operating state of the equipment is displayed through the indicator light HD. To ensure that the operating state of the equipment remains unchanged during the switching process between manual control and automatic control, when switching from automatic control to manual control, the switch side state of the contactor is paralleled with the start button; when switching from manual control to automatic control, the controller reads the current operating state of the equipment and the state of the control mode conversion rotary switch, and designs an equipment operating state maintenance program to ensure seamless switching of control.

[0045] The present invention designs a set of manual and automatic control systems for the crushing and screening process of fused magnesia. In the automatic control state, the controller can automatically adjust the feeding speed and crushing speed according to the parameters of various devices and technological parameters detected on site, ensuring the safe and continuous operation of production. At the same time, it can complete the seamless switching between remote automatic control and local manual control, ensuring the reliability of production, improving production efficiency and the utilization rate of raw materials.

Claims

1. A manual and automatic control system for the crushing and screening production process of fused magnesia, characterized in that, Comprising: A manual-automatic switching control unit, an actuator connected thereto, and a sensing unit; The actuator includes a first frequency converter and a first motor connected thereto, a second frequency converter and a second motor connected thereto, and a third motor; the first motor is connected to a blanking bin in the electric feeding device; the second motor is connected to a crusher in the crushing device; the third motor is connected to a vibrating screen in the electric vibrating device; The sensing unit includes a vibration amplitude detection device and a vibration return material detection device; the vibration amplitude detection device is arranged on the vibrating screen of the electric vibrating device; the vibration return material detection device is arranged on the material return channel between the vibrating screen and the crusher; The first frequency converter, the second frequency converter, the vibration amplitude detection device, and the vibration return material detection device are all connected to the manual-automatic switching control unit; An air switch QF, a contactor KM, and a thermal relay FR are sequentially connected between a three-phase power supply and the three-phase input ends of each of the first motor, the second motor, and the third motor; The manual-automatic switching control unit includes three control circuits, which are respectively connected to the first frequency converter, the second frequency converter, and the third motor; The control circuit includes a rotary switch, a start button SB1, a stop button SB2, and an emergency stop button SB3, which are sequentially connected between any two phases of the three-phase power supply; the start button SB1 is connected to the manual control side output end of the rotary switch; Three control input ends of the controller are respectively connected to the automatic control side output ends of the rotary switches of the three control circuits, and three control output ends of the controller are respectively connected to the first frequency converter, the second frequency converter, and the third motor; the controller is connected to the vibration amplitude detection device and the vibration return material detection device; Both ends of the start button SB1 in the control circuit are respectively connected to a pair of contacts of the contactor KM, so as to control the start of the motor corresponding to this control circuit through the start button SB1; The emergency stop button SB3 is connected in series with the contactor KM coil and the thermal relay FR coil, so as to control the stop of the motor corresponding to this control circuit through this control circuit; The vibration amplitude detection device is an amplitude sensor.

2. The manual and automatic control system for the crushing and screening production process of fused magnesia according to claim 1, characterized in that, The vibration return material detection device is a powder flow meter.

3. The manual and automatic control system for the crushing and screening production process of fused magnesia according to claim 1, characterized in that, The control circuit further includes an indicator light connected in series with the emergency stop button SB3.

4. The manual and automatic control method of the manual and automatic control system for the crushing and screening production process of fused magnesia according to claim 1, characterized in that, Including the following steps: The control mode is switched by turning the rotary switch SA. When the rotary switch SA is connected to the controller, it is in the automatic mode; when the rotary switch SA is connected to the start button SB1, it is in the manual control mode; When switched to the automatic mode, according to the detected vibration return material flow rate, vibrating screen vibration amplitude, and frequency converter current, the controller controls the first motor and the second motor to respectively control the blanking speed of the blanking bin and the crushing speed of the crusher: When the vibration return material flow rate is greater than the preset value, the second motor is controlled to increase the crushing speed of the crusher, and the first motor is controlled to slow down the blanking speed of the blanking bin or stop; when the return material flow rate returns to the normal range, the first motor is then controlled to increase the blanking speed of the blanking bin; When the current of the second frequency converter increases within the set time, control the first motor to slow down the feeding speed of the feeding bin or stop feeding until the current of the second frequency converter returns to the normal value, and then control the first motor to increase the feeding speed; When switching to the manual control mode, start and stop the actuators corresponding to the control loop by operating the start button SB1, stop button SB2 and emergency stop button SB3 in different control loops.

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