Heat and mass transfer enhancement during absorption process with double-side film-inverting configuration
Film-inversion is an effective way recently developed to enhance heat and mass transfer in absorbers.However,only one-side of round or rectangular tube i.e.half of the total heat transfer area is used to form film-inverting configuration in the published literatures.This paper presents a double-side film-inverting scheme,which consists of two plate bundles with two-scale crosswise corrugations and a set of comb shaped conjunctions for leading the film from both sides of each couple of the upper plate bundle to the opposite sides of the bottom one.The horizontal corrugation can make film distribution uniform before and after inversion with the surface tension effect,and thus increase the heat and mass transfer coefficients of the absorption process.A mathematic model for heat and mass transfer in absorption process with aqueous Li-Br solution falling film-inverting on two sequential vertical plane plates was established and calculated numerically.The velocity profiles,temperature and concentration distribution inside the solution film were obtained.The influence of the number of inversion on heat and mass transfer characteristics was analyzed.The calculation results show that the heat and mass transfer coefficients of the once-film-inverting scheme increased by about 58% and 73% respectively over these of the none film-inverting scheme.