The Intrinsic Permeability of Packed SiC Particles with Monomodal and Bimodal Size Distributions

Abstract

The intrinsic permeability k of preforms of packed -SiC particles having monomodal and bimodal particle size distributions has been evaluated by pressureless infiltration of a wetting organic fluid at room temperature. The study was carried out using SiC particles of average diameters in the range 4.88-168 mm and bimodal mixtures of particles with diameters of 16.9 and 168 mm. The experimental results for monomodal preforms can be fitted by Hazen's law, k / D(10) m , D(10) being the particle size for which 10% of particles are finer, with an exponent m ¼ 1.76 not far from that proposed by Hazen (m ¼ 2). Data for bimodal mixtures cannot be, however, described by Hazen's law due to the large changes in volume fraction that are promoted by varying the relative amount of the two particles. Instead, data for both monomodal and bimodal preforms can be satisfactorily fitted by Kozeny-Carman equation that incorporates particle volume fraction as one of the parameters.

Insights into the flow behaviour of the AR24 mesophase pitch and nanoparticle-doped AR24 mesophase pitch during infiltration into particulate porous preforms

“…By taking φ=0.42 and S=320 m 2 /kg, permeability can be calculated to be K=3.02×10 -13 m 2 , which is in accordance with other works in which particles of similar specific surface areas were packed by the same procedure [18]. This value represents the so-called intrinsic permeability since preforms are spontaneously wetted by a liquid with a small enough contact angle to insure full saturation [17,18]. (1,4-7), the curve that best fits the experimental results (Figures 4b and 4c) is obtained for a permeability of 3.06×10 -13 m 2 , which well agrees with the former result for experiments E1.…”

“…The slope of a linear fitting of z 2 vs. the t data for experiments E1 allows permeability to be calculated. By taking φ=0.42 and S=320 m 2 /kg, permeability can be calculated to be K=3.02×10 -13 m 2 , which is in accordance with other works in which particles of similar specific surface areas were packed by the same procedure [18]. This value represents the so-called intrinsic permeability since preforms are spontaneously wetted by a liquid with a small enough contact angle to insure full saturation [17,18].…”

“…The permeability of the packed preforms of NaCl particles was obtained by performing infiltrations with polyethylene glycol (PEG) at ambient temperature (25ºC). This procedure was demonstrated as being effective and appropriate for a large number of different packing particulates [17][18][19], provided that PEG properly wets the surface of particles and can hence spontaneously flow into the porous preform under its own capillary pressure.…”

Wetting and Navier-Stokes Equation — The Manufacture of Composite Materials

“…First the GPI technique will be analyzed, and for this purpose, the example of a laboratory equipment developed at the University of Alicante will be used [10,11,[21][22][23][24][25][26][27][28][29]. A scheme of the equipment is shown in Figure 1.…”

“…The contact angle between a flat substrate and a drop of liquid metal can be routinely measured by the method of the sessile drop. However, this measurement is not possible when the solid is in particulate form, in which case the wetting can be studied by means of liquid metal infiltration into compacted particulate samples [10,11,[21][22][23][24][25][26][27][28][29].…”