Experimental Study About Deposition Characteristics Of Fine Particles On Indoor Wallpaper

Many research results have proved that the particle size distribution and pollution degree of indoor particulates are closely related to the indoor pollution sources and the local atmospheric environment.And compared with the outdoor ones,the main particulate matter(PM2.5)is dominant.However,due to the complex physical properties and chemical composition of the fine particles,they are extremely harmful to human health.How to remove indoor fine particles has become an urgent problem to be solved.Wallpaper has gradually become the main material for indoor wall decoration in China since the 1970 s and 1980 s.Its use solves the problem of break marks and odors caused by painting and paint decoration.And because of its advantages such as low price,convenient construction,and luxurious style,wallpapers are widely used in wall decoration of houses,offices and hotels.If the wallpapers with rich patterns and uneven surface have a promoting effect on the deposition of particles,this will play a positive role in reducing the particle size distribution and the concentration of particles in the indoor particles.In order to study the specific effects of wallpaper surface characteristics on the deposition of particles,this paper mainly carried out the following work:(1)Surface roughness is an important parameter that affects the surface properties and surface effects of an object.Usually,the average roughness Ra is used as the basis for discrimination.The greater the value of Ra,the rougher the surface of the object.The non-contact laser microscope was used to calibrate the average surface roughness Ra of the wallpaper surface by ten points method.The wallpaper samples were divided into two groups to discuss the effect of the surface material of the wallpaper and the surface roughness of the wallpaper on the deposition rule of the particles respectively.(2)This experiment was carried out in a fully enclosed aluminum laboratory cell(0.8m x 0.8m x 0.8m)using a particle concentration decay method.According to the measurement results under the experimental conditions,it is found that the surface material of the wallpaper has a small influence on the deposition rate of the particles in the range of 0.4?m to 1.8?m.However,the deposition rate of each particle size particle increases with the increase of the surface roughness of the wallpaper,especially the larger particle size.(3)The increase of wind speed in the small room plays a role in promoting the deposition of particles on the surface of the wallpaper.When the fan speed in the small room increases from 1018 rpm to 1527 rpm,on the surface of the PVC wallpaper with an Ra value of 95.778?m,the deposition rate of particulate matter increases significantly with the increase of wind speed in the small room.However,when the fan speed is increased from 1527 rpm to 2800 rpm,the deposition speed of particles is only moderately increased with the increase of wind speed.Especially for particles smaller than 0.9?m,the value of the particle deposition attenuation coefficient hardly changes with the increase of the fan speed in a small room..