INVESTIGATION OF STRUCTURAL CHARACTERISTICS OF FILTER MEDIA PART II:ANALYSIS OF SPECIFIC PERMEABILITY AND PORE STRUCTURES

摘要

An examination of both specific permeability and pore size by theoretical andexperimental methods is presented and a relationship between these two important parametersestablished. Depending on the surface finish,the porosity does not always have a closerelationship with the specific permeability. The models for predicting the specific permeabilitywere examined,and it was found that Davies’s model fits well with singed and non-surfacefinished needlefelts,whilst Langmuir model with calendered needlefelt nonwoven. For surfacefinished needlefelts,pore size measured by the bubble point fit well with those calculated byHagen-Poiseulle law; and for non-surface finished needlefelts,with Wrotnowiski method. Poresize is governed by surface pores. It changes non-linearly at below a certain specificpermeability (k),and above that point,there is a linear relationship with permeability k.