Study On Scale-Up Of Conical Twin Screw Extruders For Energetic Materials

Energetic materials are indispensable energy materials in the field of aerospace and military industry.The progress and development of its processing technology and equipment plays an important role in promoting the construction of the national aerospace industry and the improvement of defense level.The continuous plasticizing and dehydrating of energetic materials by conical twin-screw extruder can improve production efficiency and the processing safety of energetic materials.At present,the production efficiency of energetic materials is limited by the lack of large conical twin screw for energetic materials.To establish the scale-up theory of conical twin-screw,realize the scale-up of conical twin-screw extruder for energetic materials,ensure the processing safety of energetic materials and maintain the consistency of processing performance have significant meanings for the development of large-scale conical twin-screw extruder as well as the continuous and large-scale production of energetic materials.In this paper,the scale-up theory of the conical twin-screw extruder for energetic materials was established by infinitesimal method.The scale-up design of the machine was carried out,and the scale-up effect was studied.The main work completed in this paper is as follows:(1)Based on the characteristics of each functional section of the conical twin-screw extruder used for energetic materials,the conical twin-screw extruder was dispersed along the axial direction by the infinitesimal method.According to the characteristics of different functional sections of conical twin-screw extruders used for energetic materials,the scale-up theory of conical twin-screw extruders was established,and the scale-up exponential relations of the performance parameters of the conical twin-screw extruders were deduced.(2)According to the developed reference model,the scale-up design of the machine was completed and the geometric model of the machine was established according to the scale-up theory of the conical twin screw for energetic materials.(3)Based on the numerical simulation of PolyFlow,the effects of groove depth index,rotational speed index,gap index and length index on the performance parameters of the screw in the melt conveying section,including output,shear rate,shear stress,residence time,pressure and temperature distribution,and the reasons for their effects were studied by single factor test method.The scale-up effect was studied by comparing the theoretical values of the performance parameters with the numerical simulation results,and the scale-up exponential relationships were modified according to the single factor variation curve.(4)Applied with the analysis of range and variance of orthogonal test,the significance of the influence of the main scale-up index in the melt conveying section on the performance parameters of the scaled-up machines were explored and the theoretical analysis was conducted.According to the order of significance,the scale-up exponential relation is modified.At the same time,the scale-up effect of the scaled-up machines under the multi-factor variables was studied,and the scale-up theory of conical twin-screw extruders for energetic materials is modified.