i 
DUST EXPLOSIONS IN GRAIN SEPARATORS. 5 
NATURE OF EXPLOSIONS. 
The nature of the explosions and fires in 117 cases can be sum- 
marized as follows: 
Hezplosions. Fires. 
SUUKOIG LENO ag THOU ee a G37) Without explosionss==3 ts 21 
Very viOlemtiat ease cae tim BE) 8 | Nature not determined —_—_- =| 1 
Serer ile 2 ea Ea ee a 10 —. 
Shichtvexplosiones 22 eo igs Bee 2 22 
Miuriiled gang. Quick.282s mae one 5 
Flame followed by explosion_____ ef 
Metonation; LepOLt= == ase 1 
95 
This table indicates that at least 95 of the occurrences, or 81 per 
cent, were dust explosions. In the remaining cases where there was 
sufficient flame to damage the machine the fire was not accompanied 
by as loud reports as in the other instances. The ignition was not 
so rapid and the rate of burning accordingly slower. 
POINT OF ORIGIN OF EXPLOSIONS. 
Special efforts were made by the investigators to locate the point 
of origin of the explosions and fires. The results in 108 cases can be 
summarized as follows: 
Back of cylinder or hear this Graine amas 2 steer ek se een 1 
OUIN pare Nees eee ees Se EP SZaE Straw sstack= mn men ei ean 1 
Mnpineemachinestecss. ah ease ls 9) | Pacis. of machine. lt a= ages eis 
Belin Gh kigives 222 220 ko siya (33.00) WN CINe Sse el 5g i be ee ak 
SLOG reenter ee ose Vea 4 PR's 
CentersOLemachine 9222 he i er 2 108 
MrOnteOremaAcGhine si] hes tae 2 
At least 82 of these occurrences, or 76 per cent, originated back of 
the cylinder or very near this point, indicating that the source of 
ignition in a large majority of cases was near this part of the 
separator. 
LOCAL OPINION AS TO CAUSES. 
Dnring the preliminary field investigations an effort was made to . 
interview the thresher agents of the various companies in the vicinity - 
of Spokane and other interested parties with a view to obtaining 
information pertaining to the local opinion regarding causes of pre- 
vious explosions and fires. Prior to 1914 occasional occurrences of 
this nature had taken place throughout the Pacific Northwest, but 
until 1914 general interest was not awakened. During that year, 
owing to the frequency of the explosions and fires, local interest was 
greatly increased. 
