The Research And Analysis Of Underwater Pelletizer Die Plate

The pelletizing equipment is an important processing machinery for the petrochemical industry. With the rise of the polymer processing industry, underwater pelletizer as a kind of high efficient granulation device, is increasingly favored by the processing industry. As a key component of the underwater pelletizer group, die plate play a crucial role in the pelletizing process, it usually work in the high temperature, high pressure, corrosion, high-friction environment, after long time using it will appear inevitably template damage phenomenon. The normal production processing usually delay because imported diced template price is expensive, and the delivery cycle is too long, it seriously hampering the development of China's polymer processing industry. In order to quickly master the main properties of underwater pelletizing and save costs, we especially do some numerical simulation.This article designed the underwater pelletizer, and do some simulation of the flow field, temperature field, pressure field under the damage of the die plate during production. The steps of the method used in this paper: The determination of the numerical method, the establishment of physical model, the establishment of mathematical model, numerical simulation experiments.The simulation of flow field shows that the molten polymer's flow speed increase as the diameter of the model hole constantly smaller. The simulation of temperature field shows that the temperature of the region close to the pelletizing surface is relatively low with a sharp temperature, while the temperature deeper inside the die is higher; the Convective heat flux of temperature field has showed the distribution, the size and the direction of temperature. The simulation of pressure field shows that the maximum stress of die plate appeared in the joint between die holes, also appeared in the convex platform root fillet of die plate. When change the size of fillet, the stress of die plate will change too; the size of stress was not directly decided by the size of fillet; the maximum stress of die plate appeared in Rl.2, and the minimum stress of die plate appeared in R1.39.The research and numerical analysis of the pelletizing die plate provide more reliable theoretical basis for the optimization of the die plate's structure designing, and also has guiding effect on production.