Design Of Automatic Weighing System For Conveyor Belt Conveying

Weighing ingredients are widely used in industrial production.Aiming at the actual needs of the active ingredient extraction production line of seaweed,an automatic weighing system for conveyor belt feeding is designed.The materials needed in the production process are stored in high-level storage tanks.Conveyor belts run under the storage tanks.Material release is controlled by solenoid valves.When the solenoid valve is opened,the material is discharged and the conveyor belt is kept running to avoid the accumulation of materials.The weighing instrument dynamically weighs the weight of the material.When the present weight is reached,the solenoid valve is closed.In order to ensure the accuracy of the weighing,the operation of the conveyor belt must be carried out in coordination with the feeding process.That is,when the specified length of the conveyor belt is stopped,the blanking operation should be completed.At this time,static weighing is performed to obtain accurate weight.This amount is subtracted from the total weight to calculate the next amount of material.This process will repeat several times until the total weight of the material reaches the set value.The main work focuses on the following aspects.First,the composition and working principle of the automatic weighing system are introduced.This entire system consists of a mechanical section,a sensor section and an electrical instrument section.The mechanical part with strict protection level mainly constitutes the transmission and main frame of the system.The weighing sensor sends real-time weighing data to remote PLC by outputting 4~20m A DC.The electric instrument includes PLC,touch screen,three-phase stepping motor,etc.Second,the selection of touch screen,PLC,weighing sensor,stepping motor and its driver,as well as the corresponding hardware connections and electrical schematics are completed.The I/O assignment of the PLC are performed,the data conversion methods of the weighing value are designed,and the parameters of the driver are set.Third,the PLC control program and touch screen interface are designed and debugged.According to the actual production requirements,the working methods of dynamic transportation and static weighing are designed and the corresponding work flow is drawn.Based on this,the PLC control program is designed,including data processing,stepping motor speed calculation,stepping motor control,manual mode and automatic mode;the touch screen interface includes parameter setting interface,parameter display interface and I/O status monitoring interface.The system has been used in Qingdao Seaweed Group Co.,Ltd.for more than one year.The actual operation shows that the control system has the advantages of high weighing accuracy,high efficiency and smooth operation.This system fully meets the actual requirements.