Electrostatic fire hazard analysis —electrostatic discharge
electricity can generate high voltages and electrostatic fields. If the
electric field strength exceeds the dielectric breakdown electric field of the
nearby dielectric, discharge will begin. Generally speaking, the dielectric
constant of gas is smaller than that of liquid or solid, so it is easier to
discharge. Preventing gas discharge, especially the discharge in the air, is
the focus of electrostatic fire prevention.
discharge can be divided into air discharge and surface discharge. The air
discharge includes corona discharge, brush discharge and spark discharge. There
is no essential difference between the various discharge forms, and the
difference in the discharge form depends on the amount of charge. Distribution
and leakage rate.
discharge generally occurs between different electrodes that are far apart and
have sharp protrusions on the surface. Partial air ionizes during discharge,
the discharge energy is small, and the risk is small.
discharges mostly occur on insulators. During discharge, the air between the
electrodes is broken down, forming many bifurcated discharge paths. The
discharge energy is slightly larger than that of corona discharge, which is
discharge mostly occurs between metal objects. The air between the electrodes
is broken down during discharge, forming a very concentrated discharge path, and
the risk of ignition is the greatest. Preventing spark discharge is a static
hazard that needs special control in the chemical production process.
main reason for the damage caused by static electricity is that the
electrostatic discharge spark has enough energy. The calculation formula is as
Q——electricity, C; C——capacitance, F; U——static voltage, V; E——discharge