Research On Vibration Reduction Technology Of High Density Polyethylene Discharge Pipeline

Power discharge pipeline is designed to deliver raw materials and products for the main purpose, and it is widely used in chemical production processes. High density polyethylene discharge pipeline delivering is one of methods for transporting granular of polyethylene material by use of pressurized gas and a certain flow rate. However, in the actual operation of the pipeline, due to the impact of the fluid to the pipeline, vibration transfer of mechanical and other factors, the pipeline will be induced to intensive vibration which may cause damage to the pipeline and even lead to personal injury and production loss. In order to maintain reliability of pipeline in the industry, one necessary in-depth cause study of vibration and the method to control the vibration.Firstly, this paper introduces analysis and research status of pipe vibration problem national and abroad. A study of resonance parameters of pipeline, simulation analysis dynamic characteristics of pipeline and stress analysis after the vibration control of the pipeline in combining theory with practice are presented. It provides a theoretical foundation of analysis of pipeline vibration and a feasibility of piping vibration controls. The main contents are as follows:1) ANSYS analysis software was used to establish a solid model by PIPE pipeline unit. And then, the pipeline natural frequencies and mode shapes were analyzed, and the main pipe resonance parameters and combinations of main vibration area are obtained. At the same time, the condition of impact of fluid on pipeline elbow was assumed and found the vibration amplitude of the main pipeline region by transient response analysis method. In order to reveal the vibration characteristics of degassing bin to pipeline, three kinds of harmonic conditions were compared, it illustrates that the influence of different forces on the pipeline vibration frequency and amplitude. Finally, on and off line tests were conducted and vibration data were collected. The cause of the vibration of the pipeline is obtained combined with the pipeline operating conditions, simulation results and actual measurement results.2) According to the structure of the pipeline project, the actual vibration parameters and results of the vibration analysis in simulation and experiment, the program of use to reduce vibration of the pipeline are proposed, and proper type of damper was selected. In order to verify the reduce vibration effect of damping, the ANSYS dynamics simulation analysis of the pipeline structure is conducted, it compared the data of main vibration frequency, maximum amplitude with that which prior to the system improved. Results indicated that improve proposal can effectively keep the pipeline system away from original pipe resonance frequency, reduce the amplitude of the pipe vibration, and further improve vibration reduction proposal.3) Using pipeline stress analysis software CAESARII which is widely used, it established a solid pipeline model and simulated two kinds of prior to before and after the installation of dampers, which shows two kinds of maximum stress are allowable values, and ful y proved the feasibilities of damping solution.