12 Property Function to Compute the Dustiness of Powders
425
The dustiness number S SD is derived from the maximum attenuation of light E MAX
and the light attenuation E 30 , which is recorded 30 s after the drop of the sample
(Eq. 1).
S SD = E MAX + E 30
(1)
3.2.2 Rotating Drum Method
To simulate mixing and filling of powders, the rotating drum testing method according
to DIN 55992-1 is used. Schematics of the method are shown in Fig. 15. A powder
sample (100 g) is placed in the rotating drum of the apparatus. By rotation with a
fixed rate of 30 rpm the sample is simultaneously mixed, dropped and dispersed as
shown in Fig. 16. An axially induced air flow, generated by the service modul will
transport the released particles out of the rotating drum, beyond a separator for coarse
Fig. 15 Schematics of the rotating drum testing method according to DIN 55992-1
Fig. 16 Demonstration of
the rotating drum method
sample straining
(counterclockwise rotation)
425
The dustiness number S SD is derived from the maximum attenuation of light E MAX
and the light attenuation E 30 , which is recorded 30 s after the drop of the sample
(Eq. 1).
S SD = E MAX + E 30
(1)
3.2.2 Rotating Drum Method
To simulate mixing and filling of powders, the rotating drum testing method according
to DIN 55992-1 is used. Schematics of the method are shown in Fig. 15. A powder
sample (100 g) is placed in the rotating drum of the apparatus. By rotation with a
fixed rate of 30 rpm the sample is simultaneously mixed, dropped and dispersed as
shown in Fig. 16. An axially induced air flow, generated by the service modul will
transport the released particles out of the rotating drum, beyond a separator for coarse
Fig. 15 Schematics of the rotating drum testing method according to DIN 55992-1
Fig. 16 Demonstration of
the rotating drum method
sample straining
(counterclockwise rotation)