Study On Electrostatic Electrification Characteristics Of Polyolefin Powder In Pneumatic Conveying Pipeline

In the chemical industry,the production and processing of polyolefin powder requires various transportation and handling,and pneumatic conveying is a method suitable for modern powder transportation needs.However,polyolefin particles with high specific resistance often cause problems due to electrostatic charging,including pipeline blockage caused by particle aggregation in the pipeline,and explosion accidents caused by static electricity.Therefore,this article studied the charging mechanisms of four representative polyolefin conveying systems and summarized the effects of different influencing factors on the charging of polyolefin particles,which is of great significance for ensuring the safe and efficient operation of the pneumatic conveying process.This article investigates the mechanism of electrostatic generation in polyolefin powder in a complete pneumatic conveying system and charge measurement system.Comparative analysis was conducted on the electrostatic effects of four types of polyolefins and two particle sizes under different gas-solid conditions.The research results indicate that:(1)When transporting polyolefin powder in a stainless steel pipeline,it was found that polyethylene,polypropylene,and PETG(polyethylene terephthalate)powder were negatively charged,while ABS(acrylonitrile butadiene styrene copolymer)powder was positively charged.As the flow rate of the conveying air increases,the charge to mass ratio of polyethylene and ABS powder(1 #)gradually increases,while the charge to mass ratio of polypropylene and PETG powder(1 #)will reach its maximum value.As the mass flow rate increases,the charge to mass ratio of polyethylene,polypropylene,and PETG powder(1 #)gradually decreases,while the charge to mass ratio of ABS powder gradually increases.(2)Compared with the results of polyolefin powder(1 #),the change in electrostatic charge to mass ratio of polyolefin powder(2 #)is very small when the mass flow rate remains unchanged and the conveying air flow rate increases;When the airflow speed remains constant but the mass flow rate increases,the charge to mass ratio of polyethylene,polypropylene,and PETG powders exhibits the same pattern,but the change amplitude decreases,while the charge to mass ratio of ABS polyolefin powder(2 #)exhibits the opposite change pattern.(3)In the transportation process,the generation and influence of static electricity can be avoided by adjusting the movement state and distribution of the powder,using the same polyolefin powder with the same particle size as far as possible,and using external factors such as antistatic agent and static elimination device.