Factors And Methods Of The Fiber Collection Efficiency

In commercial and household environment Porous fiber are main treated of particulate airpollution. Over the past50years, scientists of global have been trying to study the development ofmathematics in order to predict the performance of fiber filter and improve its efficiency. FromKuwabara’s works originated, There have been many models to forecast application fiber pressureloss and collection efficiency, but most of the research is to simplify the arrangement willbe perplexing fiber filter the actual fiber irregular to regular arrangement, but the real fiberis composed of shape column different staggered fiber filter media, the limitations of thetraditional circular fibers in single fiber filter media, ignoring the cross section deformation effecton fiber filter, and in these works most research is using Lagrange method，And in these works areused in most studies focus on the Lagrange method, tracking the motion of the fluid particles, butfew people pay attention to the flow field at each space point and the process enoughspace point much together the whole concentration.In order to study Concentration of dust contained gas in the filter in the whole fluid andStudy on the more realistic microscopic filter model,,The main research work and conclusions areas follows:（1）In the microscopic view,for single fiber filter model and random generation of fibermodel，trapping efficiency were simulated, using Lagrange method and Euler method.In a macropoint, the fiber filter was simulated by Euler method, the simulation results show:the Eulermethod, Lagrange method of simulated results are in agreement with experiment results, Eulermethod simulation convergence is significantly faster than the Lagrange method, thesimulation results when added in the source term is very close to the calculated value, when thefiber surface add wall boundary conditions， the simulated results are slightly lower thanefficiency theory model, but is still good said the relationship between fiber collectionefficiency and the fill rate,the speed,the results agree very much.(2)Based on the VBA development technology as the platform， through the AUTOCADsoftware, generating random fiber procedures, the procedures of generation random fiberfilter model was import into the CAD, mainly control the fiber diameter, porosity, parameternumber of fibers to generation of different shaped degree,different filling rate,different fiberdiameter, for generating model.Using the Lagrange method, solving the motion trajectory of particles on the fiber medium, through the statistics particulate number byfiber traps, gain fiber medium collection efficiency. And using of filter performancequality comprehensive evaluation factor of virtual fiber filter media. In his paper,alien degree andshape factor be used to studies the impact of different geometric cross section shapeof fiber on the collection efficiency, pressure drop and quality factor. The simulation results showthat: the effect of alien degree and shape factor on collection efficiency is high whenfiltration velocity was small; The pressure drop increases with the Shape factor. In the filling rate<0.19, the collection efficiency of trilobal fibers is highest at the same time the pressure drop isthe biggest; The fiber has good trapping effect for diameters less than2μm particles.Whenthe fiber diameter is equal to30μm，for relatively small particles,The quality factor increased firstand then decreased as the increase of fiber Particle Shaped degree,trilobal fibers is thebeast.When the fiber diameter of5μm,quality factor decreases first and then increases withincreasing alien degree, round fiber of the quality factor is the highest.To validate the reliabilityof simulation method, we compared the simulation results of circular fibers with theliterature,the results show simulation are consistent with the literature research.