Research And Design Of Control System About The Conveying And Weighing Of Cullet

Cullet is the material and intermediate product in the production of glass. The conveying, weighing and the proportional control in the glass batch of cullet are important links of the glass production. Bucket elevators are widely used in small middle and small sized production line, which often leads to the occurrence of blockage. So it is meaningful to study the conveying and weighing processes of cullet, in order to reduce the failure rate and improve the accuracy of blending process. An equipment arrangement mode and system design is described, which means we replace the bucket elevators with belt weigher, weigh the cullet when it is moving and spray it on the raw materials. The main research contents are summarized as follows:The conveying process and weighing mechanism are analyzed. In the aspect of hardware, pressure sensor and speed sensor are used in data acquisition, with there type selected. After the control methods are analyzed, the amplitude control of feeder is chosen to adjust the flow of cullet. The model that cullet and raw materials constitute the open-loop ratio control of flow is raised.In order to carry out the function of data acquisition, data processing and feed back control, the conveying and weighing control unit circuit is designed based on DSP and CPLD. The circuits include data acquisition, data processing, logic control, interface, alarm circuits and so on. The DSP improves the data processing speed and accuracy. The CPLD is used in measuring the rotational speed and logic control, which reduces the board area.In order to control the cullet flow, based on comparative analysis of control algorithms, PID control and fuzzy control, the P-fuzzy-PI multimode control algorithm is chosen to apply in the software design. And the simulation is carried out to view the follow effect in the ratio control system. Besides, based on the hardware design, the DSP software is designed to achieve the data processing function. The internal logic connections of CPLD is compiled in VerilogHDL language, so that the control unit can achieve the functions of signal sampling, flow parameter display, communication with upper computer, adjusting the open angle of actuator and so on.The designed cullet conveying and weighing control system avoids blockage and reduces a hopper in equipment layout. The method of dynamic weighting on belt weigher and flow control of feeder can finish the proportioning production process. The P-fuzzy-PI control algorithm can adjust the flow for different period of proportioning.