Extensive knowledge is nowadays available with respect to the ignition risks due to
static electricity associated with the handling and processing of flammable liquids
based on research and experience from the petroleum and chemical industries.
The hazards associated with charge build-up on packages, containers, apparatus
and plant items have to be eliminated by an adequate choice of the material for
construction and by earthing and bonding all conductive parts (see also spark,
0.01
0.1
1
10
100
1000
10000
0.5 1 1.5 2 2.5 3
silo diameter m
equivalent energy m
J
100 µm
400 µm
1000 µm
3000 µm
11
brush and propagating brush discharges). In addition earthing of the personnel via
charge dissipative shoes and floors is mandatory.
The hazards associated with the charge on liquid products is given by the
equilibrium resulting from charge separation, charge accumulation and charge
dissipation (see Figure 1.) The parameters affecting this charge equilibrium state of
the liquid are manifold. A summary is given in Table 1.