Effect of moisture on the yield locus of granular materials: theory of shift

Experimental and theoretical analysis of TiO2 powders flow properties at ambient and high temperatures

“…Furthermore, the flow properties at realistic process conditions need to be evaluated in order to analyse to what extent physical and mechanical particle properties (Pilpel and Britten, 1979;Fu et al, 2012;Liang et al, 2012), temperature (Kanaoka et al, 2001;Tomasetta et al, 2011;Chirone et al, 2016), humidity (Pierrat and Caram, 1997;Pierrat et al, 1998;Teunou and Fitzpatrick, 1999;Gröger et al, 2003;Landi et al, 2011) and loosely compacted conditions (Kono et al, 1994;Bruni et al, 2007b;Barletta and Poletto, 2012) affect the flow behaviour.…”

Modelling and experiments on the effect of air humidity on the flow properties of glass powders

“…These forces are due to the combined effects of the surface tension acting on the liquid bridge interface and of the curvature of the bridge surface [1][2][3]. As a result, capillary forces cause an increase of powder cohesion and tensile strength and, thus, negatively affect the powder flowability [4][5][6][7][8]. Moreover, capillary forces modify also other powder bulk properties such as voidage, aggregative structure and permeability.…”

“…Consequently, powder flow properties are influenced by the humidity of the storage environment [6,[15][16][17][18][19]. In some of these experimental studies the liquid bridges formed by capillary condensation interact chemically with the particle surface giving rise to the so called "caking" phenomenon.…”

Wet Solids Flow Enhancement

“…The basis of the cohesive behavior of wet solids is the attractive forces due to the presence of capillary bridges, of a liquid with surface tension α and contact angle δ, as the one shown in Based on the moisture content it is possible (as discussed in reference [1]) to determine the bridge volume and the filling angle θ. It is also easy to show that the filling angle is not sensitive to the separation a between particles as is shown in Figure 5.…”