Page 143 - Advanced Mine Ventilation

124 Advanced Mine Ventilation

9.1 A Mathematical Model for Respirable Dust
Generation

Panov [5] was the first to derive a mathematical expression for dust generation based
on the physical properties of coal. He assumed that the rate of dust generation (minus
100 mm particles) is a function of seven variables and derived an expression for dust
generation as shown in Eq. (9.1).

6:5 2:5 0:5
N ¼ 35:6 a f r SA w f (9.1)
where N ¼ rate of dust formation in gm/min; a ¼ characteristic dimension of simul-
taneously broken coal; f ¼ hardness number; r ¼ density; gm/cc; S ¼ specific
fissuration; A ¼ specific energy of deformation, (erg/gm); w ¼ percent moisture
content; f ¼ percent porosity.
Fig. 9.1 shows the effect of some of these parameters on the production rate of
fines. The effect of moisture content on the rate of dust production appears to be
very significant, particularly at low moisture contents.

Figure 9.1 Rate of dust formation as a function of the properties of coal.