细水雾除尘装置去除呼吸性粉尘作用效果研究

Effect of Water Mist Dust Removal Device in Removing Respirable Dust

隧道施工过程中爆破产生的呼吸性粉尘对施工效率以及施工安全产生了极大的影响。为了了解细水雾对呼吸性粉尘的作用效果,本文以某隧道的粉尘粒径分布的现场测试结果作为背景,采用FLUENT软件建立了流固耦合的细水雾除尘数值模拟平台对水雾以及粉尘分布、水雾去除呼吸性粉尘的作用效果进行了研究。结果表明:水雾在喷头射流的惯性以及流场的带动下,在隧道环境中扩散;由于水雾的拦截与降尘作用,粉尘在隧道内呈现不均匀分布,在掌子面50 m范围内的粉尘较进口处的粉尘浓度低;在呼吸性粉尘1~10μm范围内,水雾对粒径d≥4μm的粉尘除尘率较高;随着与喷头距离的增加,除尘效率越低,在水雾5 m范围内的除尘效率最高,可以达到42%以上。研究结果可为具有除尘需求的隧道施工以及煤矿施工等工程降尘提供理论依据,对改善施工环境,保护施工人员的生命健康具有一定的指导价值。

The particle size produced during tunnel construction significantly impacts the construction efficiency and the environment.This paper established a fluid-solid coupling numerical simulation platform of water mist dust removal by FLUENT based on particle size distribution in a tunnel.The distribution of water mist and dust and the effect of water mist on removing respirable dust were studied through the simulation platform.The results show that the water mist diffuses in the tunnel environment,driven by the inertia of the nozzle jet and the flow field.Dust is unevenly distributed due to water mist’s interception and dust reduction effect.The dust concentration within 50 m of the tunnel face is lower than at the entrance.In the range of 1~10μm,the influence of water mist on particle size d≥4μm has a high dust removal rate.With the increased distance from the nozzle,the lower the dust removal efficiency,and dust removal efficiency within 5m of water mist is the highest,reaching more than 42%.The research results provide data support and a theoretical basis for dust reduction of tunnel construction and coal mine construction projects with dust removal needs and have specific guiding values for improving the construction environment and protecting the life and health of construction personnel.