Experimental Study On Deposition Characteristics Of Fine Particles On Surface Of Wet Curtain Fabric

As one of the sources of indoor air pollution,fine particulate matter has the characteristics of small particle size,large surface area,and easy to be accompanied by toxic and harmful substances.It can enter the human body through breathing,posing a great threat to human health.Studies have shown that deposition can effectively reduce the concentration of indoor particles and reduce the probability of harmful substances entering human bodies.Hanging next to the window,curtain cloth occupies a large indoor surface area and can be used as the surface of direct contact with particulate matter and high probability of deposition.Due to the influence of indoor and outdoor humidity or artificial humidification,the moisture content of curtain cloth changes,which affects the deposition of particulate matter.In this paper,the deposition characteristics of fine particles on the surface of wet curtain fabric were experimentally studied.The main work was as follows:(1)Curtain fabric samples were selected and the hydroscopicity of the selected curtain fabric samples were compared.(2)The moisture content of samples were changed,and the surface characteristics such as the distribution state of water,surface hairiness,surface roughness,fiber diameter expansion rate in samples and porosity in samples were measured,so as to provide theoretical support for the subsequent study on the influence of moisture content in samples on particle deposition.(3)The influence of moisture content,material and placement direction of curtain fabric on particle deposition were explored through deposition experiment of fine particles on the surface of sample cloth.Based on the research on the deposition characteristics of fine particles on the surface of wet curtain fabric,the main conclusions were as follows:(1)The surface characteristics of curtain fabric were affected by the moisture content of curtain fabric.With the increased of the moisture content of curtain fabric,the liquid in the gap between the sample fibers gradually increased.The hairiness and surface roughness of the surface decreased.The fiber in curtain fabric expanded withwater absorption,and the diameter expansion rate of the fiber increased.The surface porosity of the four curtain fabric samples showed a decreasing trend.(2)The deposition loss rate coefficients of fine particles decreased with the increase of relative humidity.When the air relative humidity was basically the same,with the increase of sample moisture content from 10% to 75%,the deposition loss rate coefficients of fine particles on the sample surface decreased due to the influence of surface characteristics such as surface hairiness,surface roughness and porosity.The decrease range on the surface of linen sample was 12.3%-23.4%;The decrease range on the surface of polyester sample was 12.1%-26.4%;The decrease range on the surface of polyester/viscose blended sample was 13%-21%;The decrease range on the surface of linen/viscose blended sample was 7%-23.1%.(3)In the dry environment,the deposition of particles on the surface of the dry sample might be affected by electrostatic effect,The deposition rate of fine particles on the polyester sample was the highest,the deposition loss rate coefficients of fine particles were the range of 2.2428-4.4628,and the deposition rate of fine particles on the surface of linen/viscose mixed sample was the smallest,the deposition loss rate coefficients of fine particles were the range of 1.2084-2.8962.When curtain fabric samples contained water with the same moisture content,the deposition of fine particles were mainly affected by the surface characteristics of the samples.The deposition loss rate coefficients of fine particles on the surface of polyester/viscose blended curtain fabric were the highest,while the deposition loss rate coefficients of fine particles on the surface of polyester curtain fabric were the lowest.(4)Compared with the Gravitational subsidence and Brownian motion,the airflow velocity had a more significant effect on the deposition of particles with particle size ranging from 0.425?m to 1.15?m,and the deposition loss rate coefficients of particles on the vertical surface were greater than that on the horizontal surface.