Study and design of screw parameters of the twin screw refining extruder

Twin screw refining extruder works at high consistency and is an energy and water saving refining machine, it is a co-rotating and intermeshing twin screw extruder which is special for pulp refining. The cross-section curve of the screw thread of the twin screw refining extruder based on the principles of relative movement is quite complicated, and it is not convenient to manufacture. In this paper, firstly the curve of screw thread is simplified to trapezoidal screw using the method of approach, and then the effect of the width of top spiral is analyzed by calculating the flow of materials passing through the twin screw refining extruder and a choice range of the top width of the spiral is presented. In addition, the calculation method of the volume compression ratio of twin screw rod with variable pitch is discussed. The simplification of cross-section curve of screw thread of twin screw refining extruder can not only meet the intermeshing relationship of twin screw and ensure production efficiency of the machine, but also to the cutting process of the screw thread. And this paper's work is significance for the study and design of the twin screw refining extruder.