Development of a method for weight continuous dosing of bulk materials and its implementation analysis

Weight continuous dosing of bulk materials is one of the key operations in many technological processes. As a result of analyzing methods and devices of the weight continuous dosing used by the world’s leading manufacturers of dosing systems, it was found that the main reason of decrease in the accuracy of dosing was the dynamic effects on the weight sensor. The material motion in the process of weight measuring causes these effects. The lowest dynamic impacts on the load sensor were observed when using the two-stage dosing technology. The essence of this technology lies in the fact that at the first stage separate portions with fixed weight are formed, which are fed into a vibrating tray at regular intervals and are converted into a continuous flow at the second stage. The portion weight and the time interval values are selected from the condition of equality of the given dispenser productivity to the ratio of the individual portion weight to the time interval between the supply of portions to the device for their conversion into a continuous flow. Dynamic impacts on the sensor are reduced, but are not completely excluded, since the weight of a separate portion is determined during the material motion. To increase the dosing accuracy, a new strategy in implementing the two-stage dosing technology is proposed based on the fact that constancy of the quotient could be ensured not only with the constancy of the dividend and the divisor, but also with variable values of these quantities. The proposed dosing method was experimentally compared with the prototype, which confirmed advantages of the new dosing strategy over the traditional one.