Page 208 - Dust Explosions in the Process Industries

Case Histories 781

LDERING GAS EXPLOSIONAND SUBSEQUENT
ESSFUL EXTINCTION OF SMOLDERING
OMBUSTION IN PELLETIZEDWHEAT BRAN IN A SI1
ELL AT NBRD MILLS, MALMO, SWEDEN, IN 1989

A cross-section of the silo is shown in Figure 2.22. The course of events, as recorded by
Templin (personal communication from G. Templin, Nord Mills, MalmB, Sweden, 19901,
was as follows:
Saturday 28th January, 0700: The night shift stopped the production for the weekend according to
schedule, and all activity in the grain silo plant terminated.
Saturday 28th January, 1000:According to Nord Mills’ safety procedures, the safety guard team
made its inspection round through the entire plant. Nothing special was observed. No persons were
encountered.
Saturday 28th January, 2300: A bang, muffled by the noise of strong winds, was heard in the
neighborhood, but no action was taken.

DESTROYED
SILO CELL \ /
N
zzzz

CO? INLET TUBE
~

Figure 2.22 Cross section of the silo in Malmo, Sweden,
in 1989, with smoldering wheat bran pellets, showing
inlets for carbon dioxide and nitrogen for extinction and
cooling (Courtesy of C. Templin and B. Person, Nord
INLET Mills, Sweden).