The operating commands and setting parameters issued by the upper computer of the weighing assembly line can be sent to the PLC in real time. The PLC receives the commands sent by the upper computer and controls the start, stop and speed of the vibration motor through the frequency converter. The running state of inverter is written into memory data area in real time for industrial computer to read; The various states of itself are prepared in the form of state words for the industrial computer to read in real time.
020-34563445Pneumatic conveyor is the use of nitrogen or air high-speed airflow, through the injector to make the powder in the pipeline in a suspended state, in the suspended state of the powder driven by the high-speed airflow along the closed pipeline to the end user. The process starts with the Roots blower, which can be controlled by a complete set of controllers. Open the bag filter, and the bag filter blows compressed air to the bag in the form of pulse according to the set program to remove the dust on the bag surface; Open the shaft seal valve XV-4101 of the rotary feed valve (air shutoff valve). After completing the above steps, check whether the wind pressure meets the requirements. If the requirements are met, the feeding process can be started by starting the rotary feed valve 4X01, and the powder enters the injector from the feed bin through 4X01. At this time, the powder is suspended in the pipeline under the high-speed air flow, and the powder is transported forward along the closed pipeline into the 1# or 2# powder receiving bin. Access to the receiving bin 1# or 2# can be achieved via the reversing valve XV-3101, which is equipped with a valve position switch. Each receiving bin is equipped with upper and lower limit capacitive level switches to determine whether the bin is allowed to be filled.
The control system of the weighing Batching system takes Siemens PLC as the control core (CPU is CPU313C-2DP), and is equipped with a high-performance upper computer to communicate with the PLC of the lower computer for displaying process status and action simulation, and sending operation instructions to the system at the same time. According to the site situation and process requirements, the site is a dust explosion-proof environment, and the field instrument is flameproof. The field instrument signal is sent to PLC for status indication and interlock control, PLC performs interlock control according to the stored interlock control program, starts or closes the related valves on and off, sends the switching signal to start and stop the bag dust collector, rotary feed valve (air shut-off)4X01 and Roots blower, etc. The switching signal is fed back to PLC. Interlocking control loops are introduced to ensure that various devices are in the correct state. Finally, the powder is transported to the bin outside the boundary area by compressed air along the closed pipe.
