摘要
为了研发过滤效果好、呼吸阻力低的电焊烟尘防护口罩烟尘过滤模式,以电焊烟尘为研究对象,利用扫描电镜分析了电焊烟尘的微观结构和元素构成,利用激光粒子计数器检测并统计分析了电焊烟尘的粒径分布,发现电焊烟尘中的颗粒物99%以上均为对人体危害严重的呼尘;直径0. 1~0. 3μm颗粒物粒子占粒子总数的68%以上,直径2μm以上颗粒物虽然粒子数所占比例仅为1%,但体积分数高达20%。在设计防护口罩时,上述二者均应充分考虑。利用CAD建立了a(3层过滤孔径分别为2μm、1μm、0. 1μm)、b(3层过滤孔径分别为1μm、0. 2μm、0. 1μm)、c(3层过滤孔径分别为0. 3μm、0. 2μm、0. 1μm) 3种由滤料最外层至最内层不同孔径的过滤模式,利用Fluent对3种过滤模式下速度场、压力差和电焊烟尘浓度分布等进行了数值模拟与对比分析,结果发现a模式吸气阻力最小,但粉尘过滤效果最差;c模式吸气阻力最大,但粉尘过滤效果最好,b模式居于a和c模式之间,并得出不同孔径滤料组合方案对于吸气阻力和过滤效率具有较大影响的结论。
In order to develop the filtering mode of the welding fume hitting the face mask in the nicely filtering effect and low breathing resistance,the paper has made an analysis of the microstructure and the basic composition of the welding fume by means of the electronic scanning microscope. The purpose of the electronic scanning is to check and detect the particle size distribution of the welding fume and do a statistical analysis of the particles via the laser particle counter. As a result of the above said analysis,we have found that more than 99% of the particles in welding fume were respirable dust,which is terribly harm to human bodies. What is more,the particles with a diameter of 0. 1-0. 3 μm may account for over 68% of the total particles,whereas those with a diameter over 2 μm just account for merely 1% of the total harmth,though the volume fraction stands high up to 20%. Therefore,both of them should be taken into full account in case of designing the face masks. In accordance with our research experience,3 kinds of filtering modes can be adopted with CAD,i. e.,a (3-layer filtering aperture may consist of 2μm,1 μm,0. 1 μm),b (3-layer filtering aperture should include 1 μm,0. 2 μm,0. 1 μm),c (a 3-layer filtering aperture consists of 0. 3 μm,0. 2 μm,0. 1 μm,respectively) so as to establish an internal different aperture from the external environment. Thus,in so doing,taking welding fume as a source of dust in the simulation,it would be possible to calculate and work out the velocity field,the pressure field and the concentration distribution rate of the welding fume by the effluent of the 3 kinds of filtering modes. The results of our simulation and comparative analysis can finally prove the mode we have gained tend to have the smallest suction resistance,except for the worst dust filtration effect. In addition,the mode c can enjoy the greatest suction resistance,but it is capable to produce the optimistic dust filtration effect,with mode b being between mode a and mode c. Thus,it can be concluded that the combination of the different filter materials of the pore size can be expected to bring about much greater impact on the suction resistance and filtration efficiency.
作者
陈建武
杨斌
陈振芳
孙艳秋
张晓蕾
CHEN Jian-wu;YANG Bin;CHEN Zhen-fang;SUN Yan-qiu;ZHANG Xiao-lei(China Academy of Safety Science and Technology,Beijing 100029,China;Key Laboratory of Toxic and Dust Hazards Prevention and Control Technology,State Administration of Work Safety,Beijing 100029,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2020年第3期969-974,共6页
Journal of Safety and Environment
基金
国家重点研发计划项目(2016YFC0801700)
中国安全生产科学研究院基本科研业务费专项资金项目(2019JBKY04,2019JBKY11)。
关键词
安全卫生工程技术
电焊烟尘
防尘口罩
过滤模式
粒径分布
safety and health engineering technology
welding fume
dust mask
filter mode
particle size distribution
