The Closed Loop Variable Frequency Belt Scale system mainly consists of belt scales, weighing instruments, frequency converters, regulators, star Feeders, belt conveyors, etc. The frequency converter is mainly used to control the feeding of the star feeder. The belt scale is mainly used to detect the materials flowing through the conveyor. The gravity of the materials passing through is transmitted to the weighing instrument as a signal from the weighing module. Then, the weighing instrument sends a 4-20mA analog signal to the PID regulator. Subsequently, the regulator sends two 4-20mA analog signals, one of which is sent to the DCS Weighing system and multiplied by a coefficient. As the target value of the closed-loop loop; Another path is transmitted to the frequency converter, where the V/P(with the same D/P) value of the frequency converter is calculated through the regulator, thereby adjusting the rotational speed of the star feeder to ensure that the solid materials flow evenly through the conveyor, guaranteeing a stable and accurate material flow rate. The second closed-loop control adjusts the amount of material according to the amount of material conveyed in the first loop, making the material amount change with the amount of solid material. This not only ensures the normal operation of the regulating valve but also guarantees that the solid material is mixed in a certain proportion, ensuring the accuracy of the proportioning, thereby improving the quality of the mixed material and the reliability of the system.

In the belt scale control system, the flow rate is first converted into a unified standard signal for measurement, and the connection between the signals is established. In this system, the flow signal is uniformly converted into a standard current signal, that is, a 4-20mA analog current. This current is directly proportional to the flow rate. When calculating, the flow ratio in the production process should first be converted into the ratio coefficient within the DCS, and then the ratio setting should be carried out.

To ensure the stable and accurate feeding of the feeding system, two star-shaped feeders are equipped in the two silos to supply materials to the conveyor (with belt scales inside). At the same time, two frequency converters are adopted to control the motors and provide a 4-20mA analog signal and a frequency converter conversion switch. During production, one or two devices can be selected as needed for operation This not only ensures a stable supply of materials, but also enhances labor productivity and reduces the labor intensity of employees.