Control principle of intelligent weighing system

Centralized control principle

system composition

1. Holographic high-precision weighing assembly
2. Full-protection flexible speed sensor assembly
3. On-site screen display operation terminal
4. Industrial computer (industrial computer)
5. Variable frequency control cabinet
6. Hydraulic control mechanism
7. Mobus or Ethernet (Mobus TCP/IP) open data interface
8. Holographic conveyor belt dual sweeper
9. Undamped high-precision weighing feeder
10. Scaling and correction unit
11. Weighing and metering screen display operation control cabinet
12. Automatic weighing subsystem (optional)
13. Automatic correction coefficient subsystem (optional)
14. Vehicle intelligent identification management subsystem (optional)
15. Explosion-proof video monitoring subsystem (optional)
16. Database (optional)
17. Audio-visual voice human-vehicle interaction control subsystem (optional)

（1） Holographic high-precision weighing module
1. In order to ensure the metering accuracy and reliable operation of the metering control system, the electronic belt weigher adopts imported products with original packaging, and its metering accuracy is high and reliable (± 0.5 and higher), so that it can ensure that the system control accuracy is stable within ± 0.5% or higher, fully meeting the requirements of fine coal blending control.
2. Universal damping units are set on both sides of the load cell of the high-precision spin-connected damping suspension holographic weighing mechanism to avoid the interference of the symmetric weight sensor such as vibration and impact, and to improve the stability of the load cell;
（2） Full-protected flexible speed sensor assembly
The full-protection flexible speed sensing mechanism adopts high-precision optical pulse signal, and the sensor is set at the end of the steering roller or the end of the motor. It adopts flexible connection, which has good follow-up effect and avoids the speed error caused by slipping. A thermostatic protection device is set at the speed sensor or the belt or the chain to eliminate the impact of temperature change on the speed sensor and belt tension. The speed sensor is equipped with a protective shell outside, which can effectively isolate water Dust, etc., with comprehensive protective performance and good effect.
（3） On-site screen display operation terminal
The on-site screen display operation terminal has a human-computer interface, which is in Chinese (English) language. The human-computer interaction is convenient, simple and fast. It can set various parameters, adjust and control in time. Local control buttons are set to facilitate on-site installation and commissioning, and can also be operated and controlled locally.
（4） Industrial personal computer (industrial computer)
With the features of SSD solid state hard disk, compact and stable, zero noise operation, fast startup, fast reading speed, safer storage, and multi-system, the metering data can be calculated and transmitted to the control room.
（5） Frequency conversion control cabinet
The frequency conversion cabinet and the stepless transmission work together to provide 0-72 rpm, with a larger speed range, and the power frequency and frequency conversion rotate each other. The power frequency has thermal protection, can be controlled locally and remotely, and has various indicators such as power frequency, frequency conversion and various fault alarms. Various open bus intersections such as Mobus, Prifbus-Dp, Canopen, etc. can be selected.
（6） Hydraulic control mechanism
The hydraulic control station adopts compact structure design, small size and space saving. The hydraulic pump has high volumetric efficiency and has the function of overpressure and overload overflow.
（7） Modbus or Ethernet (Modbus TCP/IP) open data interface
The system adopts Mobus or Ethernet (Mobus TCP/IP) open data interface to facilitate data opening and interaction with large management system.
（8） Holographic conveyor belt dual sweeper
The double cleaner of holographic metering conveyor belt is equipped with two sweepers, one is the conveyor head sweeper, and the other is the edge sweeper. The conveyor head sweeper has good adhesion and clean scraping. The second sweeping along the edge sweeper ensures that the conveyor mechanism has no return material, and the tare weight is stable for a long time.
（9） Undamped high-precision weighing feeder
The undamped high-precision weighing guide is processed by a high-precision large CNC machine tool at one time. This mechanism can stabilize the tension section of the conveyor belt and facilitate accurate weighing and measurement. The guide is equipped with a polymer undamped guide plate and a material shaper in the groove. The polymer plate undamped guide plate prevents the material from sticking to the wall of the guide hopper. The material shaper reshapes the material. The shaped material will not be stuck between the belt and the guide groove, It eliminates the interference of the weighing caused by the extrusion between the belt and the guide chute. The undamped high-precision weighing guide has small volume, large guide volume, fast loading and high efficiency.
（10） Tare correction, correction unit
Three different simulated load methods can be used for interval calibration: electronic calibration, hanging code calibration and chain code calibration. The instrument is calibrated according to the calibration method and calibration constant.
（11） Weighing and metering screen display operation control cabinet
The metering control cabinet calculates the collected signals and automatically controls the gate. It has high precision, high reliability and high performance, built-in PLC, switch, isolated communication port, analog quantity isolation, optical fiber transceiver and cabinet design fully consider electromagnetic compatibility, strong anti-interference ability, convenient communication, fast start and stop, safe and reliable.
（12） Description of loading automation control
1. System composition
(1) License plate intelligent recognition system
(2) Explosion-proof visual monitoring system
(3) Audio-visual voice human-vehicle interaction remote control system
(4) Centralized control operating system
(5) IPC database management system
(6) Metering system
2. System working process
(1) When the vehicle enters the silo weighbridge entrance, the vehicle intelligent identification management subsystem extracts the license plate information or the vehicle information according to the RFID data;
(2) Enter the weighbridge, collect the tare weight by the centralized control system, and store it in the database;
(3) Enter the silo, vehicle intelligent identification management subsystem or RFD acquisition terminal, query the database information according to the vehicle information or determine the loading weight according to the RFD card information;
(4) Send a signal to the central control room when arriving at the loading position for automatic loading;
(5) Explosion-proof video monitoring system, sound-light signal or voice device to realize human-vehicle interaction and prompt vehicle movement;
(6) The holographic high-precision suspension weighing unit automatically weighs and measures the loading weight, reaches the specified weight, stops loading, and lights and sounds the vehicle driving signal.
(7) Enter the weighbridge, collect the license plate information or RFD data, and collect the loading weight data to enter the database.
3. Main technical parameters and minimum size of main engine
(1) Weighing accuracy ± 0.5%;
(2) Feeding capacity of feeder 0-5000t/h;
(3) Hydraulic station power 3kw, 4kw
(4) Feeder power 7.5kw, 5.5kw, 11kw, 15kw;
(5) Ensure that the metering and feeding is not less than 500 tons per hour. The minimum height from the underframe of the metering and weighing feeding mechanism to the coal bunker inlet is 1000m, and the minimum weighing distance is 1900mm;
The installation size is determined according to the user's site space, site conditions, material size, material viscosity, material density and various specific requirements of the user. Non-standard design is adopted to maximize the space of materials and meet the requirements of on-site use to save space and the cost of supporting facilities. Small size, accurate weighing, international leading level.

Operation and maintenance

1. During the operation of the weighing automatic loading system, check whether the chain belt has sticky bottom coal and steel at any time
The seal of the sheet falls off. Pay attention to the running status of the belt, roller, idler, etc., to ensure that there is no deviation, slipping, cracking and other phenomena.
2. The high-precision weighing, measuring and feeding mechanism of the automatic loading system should be adjusted before use after the mechanical part changes
Conduct tare calibration and physical calibration.
3. In order to achieve better weighing accuracy and use effect, the normal operation period of weighing automatic loading system
Tare calibration and physical calibration should be carried out regularly. Tare calibration should be calibrated once a month, and physical calibration should be calibrated once every three months.
4. The oil in reducer, hydraulic station and other parts should be replaced regularly, and should be replaced after 500 hours of operation after installation
Once, and then run for another 1000 hours to replace it for the second time, and then replace it every 2000 hours. If it is not used for a long time, the oil should be replaced when it is used again. When the oil in the reducer, hydraulic station and other parts should be replaced, it should be replaced according to the original use type and brand to avoid equipment damage caused by replacing with different oil.
5. The working ambient temperature of the transmission shall not exceed 40 ℃, and the surface temperature of the transmission shall not exceed 75 ℃
6. The transmission should not be used at a fixed speed for a long time. It is recommended to operate every 500 or 700 hours
Make a speed adjustment.