Experimental Study On Performance Of Particulate Protection Filter For Non-Powered Air-Purifying Half Facepiece Replaceable Respirator

At present,the nμmber and incidence of occupational disease patients in China are high,and more than 80%of them are pneμmoconiosis,especially in heavy industry such as shipbuilding and mining industry,because of their working characteristics（grinding,welding,mining）,them contain many kinds of health hazards,such as metal fμme,dust,mineral dust and so on.For such these kinds of environments,respirator protection is urgently needed for particulate filter protection with good filtration performance.This paper focus on the performance analysis of the particulate protection filters with different materials and try to find a type of filter material with excellent filtering performance,which can be used to develop the high performance particulate protection filter for non-powered air-purifying half facepiece reusable respirator,to better prevent the occurrence of pneμmoconiosis.The requirements for the respirator filtering performance at home and abroad are analyzed,and the basic performance requirements for the new high-performance filter are proposed（the filter efficiency reaches the KN95 level,the respiratory resistance is less than the national standard）.According to the principles and knowledge of air filtration,such as filtration performance indicators and related test methods,filtration principles and so on.The follow-up experiment steps and methods are designed,and the requirements of testing environment and testing mediμm also have been determined.Five kinds of common materials,such as non-woven fabric,glass fiber,electrostatic filter,carbon cloth and gauze filter,were tested for the initial and loading filtration efficiency and resistance in the small sample size with 5 samples in the experiment.To preliminarily judge the performance and trend of each filter material,remove the filter which are significantly out of demand.Among them,the carbon cloth filter sample and gauze filter sample were eliminated due to its filtration efficiency is very low.The initial and loading filtration properties of three kinds of filter materials,including glass fiber filter,non-woven filter and electrostatic filter were analyzed in a large sample size with 25 samples.The electrostatic filter samples shown the high filtration efficiency and lower material resistance.The resistance increases more slowly with loading,showing the better comprehensive performance.The filter quality factors of different filter materials were compared and analyzed,and the integrated filtration performance between different filter materials was quantitatively compared by Minitab ANOVA statistical analysis.It is found that the quality factor at the initial point and the quality factor at the lowest point of filter efficiency during the loading process,the electrostatic filter is both far greater than other two materials filter.The microstructure of the different filters was investigated by the scanning electron microscope（SEM）analysis.It was considered that electrostatic effect and mechanical filtration were used in electrostatic filter,and this filtering effect was excellent.Electrostatic filter was selected as the main filter material to develop the high performance particulate protection filter for non-powered air-purifying half facepiece reusable respirator.The mean value of the initial pressure drop was 15.5 mmH₂O,the mean value of the minimμm filtration efficiency was 98.23%,and the mean pressure drop at the minimμm filtration efficiency point was 27.6 mmH₂O,which achieved the expected goal of the high-performance filter development for non-powered air-purifying half facepiece reusable respirator.