Page 192 - Dust Explosions in the Process Industries

Case Histories 165

Figure 2.7 Reconstructed head house (1 977) after the grain dust explosion at Karnbo, Norway, in
June 1976. The entire house front is covered with lightweight wall elements that can serve as explo-
sion vent panels (Courtesy of 1. Kosanovic, Karnbo, Norway).

2.3.4
MALTED BARLEY DUST, OSLO PORT SILO, JULY 1976

The explosion, described by Johansen (1976), occurred in an old silo building in the cen-
tral harbor area of Oslo at about 7:30 on a dry summer morning. The material damage
was extensive, and much debris was thrown into the surroundings. However, due to
several fortunate circumstances, there were neither loss of life nor severe injuries.
The dust involved was from malted barley, of only 5-6% moisture content. The igni-
tion source was not identified, but the explosion probably started in a silo cell and prop-
agated to other cells through the common dust extraction system. The primary explosions
in the silo cells blew up the cell roofs, which were part of the floor of the silo loft, and
gave rise to an extensive secondary explosion in the loft, blowing up the entire silo roof.
The result is shown in Figure 2.8. The damage was so extensive that the entire building
had to be demolished.

2.3.5
MALTED BARLEY DUST, OSLO PORT SILO, JUNE 1987

The explosion, described by Johansen, Johansen, and Mo (1987), occurred on a warm,
dry summer day during unloading of malted barley from a ship. There were neither
fatalities nor injuries and no damage to the building, apart from broken window panes
and a broken silo cell roof.