Interparticle voidage

Intraparticle porosity refers to the fraction of the particle volume which is occupied by internal pores most manufactured food particles are porous. However, it is important to distinguish this quantity from bed voidage. The interparticle voidage e is the fraction of the packed bed occupied by the void spaces between particles and is defined as... 

If now the cross-sectional area which determines the interstitial velocity for a given volumetric flow rate is proportional to the interparticle voidage, it follows that... 

One of the most important parameters of packed colunms is the porosity or interparticle voidage, e, which equals the ratio of void volume to packing volume. It depends on the size, shape and the roughness of particles as well as on the method of column packing, and it takes values ranging from 0.3 to 0.45. If the volume of voids is known, one can calculate the real linear gas velocity, where u is the linear velocity cal-... 

The bed void volume available for flow and for gas and liquid holdup is determined by the particle size distribution and shape, the particle porosity, and the packing effectiveness. The total voidage and the total liquid holdup can be divided into external and internal terms corresponding to interparticle (bed) and intraparticle (porosity) voidage. The external liquid holdup is further subdivided into static holdup eLs (holdup remaining after bed draining due to surface tension forces) and dynamic holdup eLrf. Additional expressions for the liquid holdup are the pore fillup Ft and the liquid saturation SL ... 

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