The weighing hopper Feeder uses a weighing module for measurement and is installed on the hopper machine. It weighs the discharge device and the hopper machine, calculates the difference between the total weight of the materials in the hopper machine and the weight of the materials after reduction. Based on the weight loss per unit time, it compares the actual feeding rate with the set feeding rate, thereby controlling the discharge device and ensuring that the actual feeding rate always accurately conforms to the set value. The weighing function is realized by using a screw Electronic scale. The screw electronic scale is a continuous conveying equipment without disturbance traction components. It uses the rotating screw to push the transported materials along the fixed casing as the surface for the conveying work. It is like a nut that is held and cannot rotate along the screw rod performing a translational movement. The force that prevents the materials from rotating together with the screw is the weight of the materials and the friction resistance of the casing to the materials. 

Spiral feeding is the most commonly used dynamic weighing feeding method in bucket scales. In the quantitative weighing device, an integrated mechanical and electronic device driven by an electric motor (commonly known as a screw feeder motor) is placed between the silo and the bucket. An electronic control device is used to achieve dynamic quantitative weighing of powder and granular materials. When the screw feeder motor is started, the powder and granular materials in the silo will rotate with the rotation of the screw feeding mechanism and enter the bucket. Three strain-type Weighing modules are installed between the bucket and the weighing frame. The weight of the bucket is directly converted into an electrical signal by this weighing module group and sent to the electronic control device. When the set weight value is reached, the screw feeder motor is turned off to stop feeding, and the bucket door is opened to unload the material, thus completing a dynamic feeding and quantitative weighing process. 

The spiral feeding device is a crucial link for ensuring the accuracy and uniformity of dynamic quantitative weighing. Due to the nonlinearity and strong non-self-balancing nature of the integrated mechanical and electrical device of the spiral Feeding machine, as well as the instability of the feeding flow caused by factors such as the particle size, moisture content of the materials, and the pressure in the silo during the feeding process, if the weighing speed is increased, the impact of the materials on the hopper will affect the accuracy and stability of the weighing; while if the weighing accuracy is improved, the feeding speed must be reduced. To reconcile the contradiction between weighing accuracy and weighing speed, most dynamic online quantitative weighing equipment currently adopts a two-stage feeding method, using a feeding control method of "fast first, then slow, and finally intermittent feeding", aiming to use "fast feeding" to shorten the feeding time and increase the weighing speed; "slow feeding" is used to reduce the impact of the materials and improve the detection accuracy; finally, "intermittent feeding" is used as a supplementary feeding method to ensure the accuracy of the final quantitative weighing. The control of the feeding process starts with "fast feeding" at the beginning of weighing, when the predicted value of fast feeding is reached, "slow feeding" is initiated; when the predicted value of slow feeding is reached, a delay is applied for the materials to fall into the hopper, if the system still does not reach the lower limit value of the allowable error of the material quantitative value, then "slow intermittent feeding" is initiated, until the net weight of the materials is greater than the given value, then the hopper door is opened to discharge the materials. Due to the fact that the time of intermittent feeding decreases as the difference in material values decreases, this effectively avoids the occurrence of deviations.