| Chemical industry is important for national economy,but high energy consumption,high pollution,and high material consumption,which are called“three highs”problems,are the main constraint for sustainable development of chemical industry.Process intensification(PI)technology is expected to solve the problem of“three highs”.Rotating Packed Bed(RPB)is the core part of Higee(high gravity)technology which is suitable for the enhancement of mass transfer,heat transfer.In the RPB,packing has significant impact on the RPB's performance,the safety and stable operation.Previous researches showed that the surface-modification nickel foam packing can further enhance the mass transfer and micromixing performance in the RPB.But the explanation of the mechanism of enhancement has no report.In addition,the stainless steel wire mesh packing,which is commonly used in industry and laboratory,is not studied.In this work,electrostatic spraying was employed to prepare the hydrophobic modification stainless steel wire mesh packing(SSP).The characterization of SSP was given.Liquid dispersion xwas studied by using a high-speed camera when liquid passes through the SSP and NSP layers.Effects of surface hydrophobicity,diameter of mother droplet,liquid velocity,liquid surface tension,and viscosity on the surface area increase rate,energy efficiency,cone angle,mean droplet diameter,and droplet size distribution were investigated by analyzing the photographs recorded by the camera.The main results were as follows:(1)Compared with the non-modified stainless steel wire mesh packing(NSP),the surface modification stainless steel wire mesh packing(SSP)shows high hydrophobicity and the contact angle can reach 124°.A film is coated on the SSP's surface without coating existing in the pores of the SSP.The rough structure of the surface is characterized by a ball and block-like morphology.The XPS of the SSP inferred that mainly elements of Fls,Cls,02 are coated on the surface.The scratch edge was smooth and the coating was still on the surface of the mesh,which shows that the adhesion of the coating film was at 0 level according to the Chinese standard.It is believed that the prepared SSP is suitable for the RPB applications to different chemical processes.(2)Visual study shows that the droplets was formed by ligament when the droplet is through the wire mesh layer.Compared with NSP,more ligaments was formed when the droplet passes through SSP.Results showed that the daughter droplet diameter was 30%smaller when droplet passes through SSP,compared with that of NSP.The surface area increase rate and energy efficiency of the SSP was higher than that of the NSP.In addition,surface tension has little impact on surface area increase rate and energy efficiency,compared with mesh size.Surface area increase rate and energy efficiency decreased with the increase of the viscosity.In this study,mesh with medium pore size and wire diameter has the highest surface area increase rate and energy efficiency.(3)The cone angle generated by the SSP was 93%larger than that by the NSP.For the droplet diameter,the mean droplet diameter generated by the SSP is-50%smaller than that of the NSP.The liquid velocity,surface tension,and viscosity have more influence on the cone angle and mean droplet diameter generated by the SSP in comparison with the NSP.The predicted values of cone angle and the mean droplet diameter were found to be in agreement with the experimental values with deviations generally within ± 15%,indicating the feasibility of this correlation to predict the cone angle and the mean droplet diameter generated by the NSP and SSP.The RRD is appropriately represented the droplet size distribution of the SSP and NSP. |
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