The weighing of the reaction tank is transmitted from the industrial computer in the control center to the electronic scale and PLC controller through the communication line, and the weight of each link is collected and displayed, and the fast feeding and slow feeding strategies are adopted in different weight stages to improve the efficiency and the measurement accuracy of the electronic scale. When the ingredients reach the target value, the output stop measurement signal, and the related valves and pumps are closed by PLC control. At the same time, the action of unloading the reactor is completed, and the measuring instrument is automatically zeroed and peeled.

Weighing the reaction pot by several raw material conveyor screw to the raw material in the order of the set to the metering scale, each raw material according to the automatic control system set the weight of the conveyor in turn, after the weight of the raw material is measured, and then by the metering scale of the discharge spiral to all the raw materials to the downstream equipment (cache bin, or direct pipeline connection), while starting the vacuum conveyor or valve. The raw material is sent to the waiting bin located above the main engine, where the weight of the raw material is completed.

The mixing and weighing system adopts Siemens PLC, circuit breakers, relays, inverters and terminals, which can complete the equipment automation and process automation control. At the same time, the configuration control means to collect the data and adopt the high-end configuration software as the upper computer, through which commands are issued to manage the automation equipment and process. Standard industrial computer software and hardware platform as an integrated carrier to replace the traditional system, with strong adaptability, openness and good characteristics.

The weighing system provides man-machine interactive interface, and completes the functions of controlling information input, data management, data display, storage, statistics and reporting, etc. The industrial computer inputs the weight of ingredients through the host keyboard, generates the weight of various materials according to the proportion of raw materials, and transmits them to PLC through communication. In the process of batching, dynamic real-time monitoring is carried out, and other switching values in the detection and control system sent by each slave machine are collected regularly, and the weight signals of each material are collected in real time and compared with the given signals to determine the next control scheme, and at the same time, the weight signals are transmitted to the upper computer.

The pulse weighing system is mainly composed of the raw material storage bin, the electric vibration feeder, the hopper scale, the weighing module, the hopper motor, and the PLC control system. According to the requirements of the task, this high-precision weighing system is applied to the weighing of metal powder in the weighing batching machine. It adopts the intermittent static weighing principle and, in accordance with the technical requirements, weighs 30 times per minute, that is, the process of discharging, weighing, and discharging is completed in each cycle period (2 seconds).

The process of weighing system is mainly the batching metering and feeding process. In batching metering process, firstly, the time of discharging from the material feeder to the metering tank is controlled according to the weighing requirements, so as to control the amount of material entering the metering bin, and then the time of discharging from the feeder to the metering tank is controlled according to the material proportioning requirements, so as to control the weight entering the metering tank, thus completing the weighing process once until the specified weighing times for each batching are completed.

The weighing loading machine is mainly controlled by PLC for the electrical control of the system, the display of the weighing instrument and the control of the weighing module. It can realize the control of the frequency converter of the separator, remote start and stop of the main motor, control of the size and speed of the tensioning station screw, display of the thrust and temperature of the main motor, and remote start and stop of the batching machine, etc. The 4~20mA analog signals collected on site are converted into weighing signals through the analog input module of the PLC. The PLC program compares the instantaneous value of the detected screw with the set value in real time internally, and controls the start and stop of the screw conveyor by the digital output template.

The movement of the mixed weighing and retaking machine is driven by two motors simultaneously. A frequency converter is added to the circuit to control the left and right movement of the screw conveyor system. The protection is mainly provided by the frequency converter without protection. When driving dual motors according to the usage requirements of the frequency converter, thermal relays are used in conjunction. The PLC outputs forward and reverse operation instructions to activate the corresponding intermediate relays. Then, the normally open point of the intermediate relay controls the frequency converter. The PLC directly sends 4~20mA to the frequency converter, and the frequency converter feeds back the speed regulation signal to form a closed-loop control.

To reduce the mechanical inertia and the deviation in loading caused by factors such as the spiral feeding of the feeding equipment, the weighing discharge machine requires the PLC to issue a signal indicating that the loading is complete before stopping the feeding equipment. The loading completion signal is sent when the weight of the hopper reaches the loading completion control value. An appropriate loading completion advance amount should be selected. After one weighing cycle is completed, the loading deviation can be calculated, and the loading advance amount for each material in the next weighing cycle can be corrected using this loading deviation.