Zusammenfassung
The electrical and atmospheric conditions found within very large
crude carriers during tank-washing operations have been reproduced
in the laboratory. Two sources of electrical discharge which are
likely to be present in a ship's tank are studied in detail -- with
particular emphasis on their incendivity. A corona-type discharge
was found to occur wherever water dripping was present, for example
from any protrusion into the tank structure such as a walkway, stairway
or strengthening structure. With an isolated 'slug' of water or metal
arranged to glance the same protrusion, a much more intense discharge
occurred between the protrusion and the 'slug'. From these two practically
important discharge sources the results clearly indicate that the
corona discharges are not an ignition hazard, under normal operating
conditions. On the other hand, it is evident that the energies involved
with the falling 'slug' discharges are in excess of the minimum ignition
energy for a representative tanker atmosphere.
Nutzer