The level of electrostatic charging depends on three factors:
- The speed of the friction of the elements.
- The humidity of the environment or if in a dry environment a discharge will occur faster if the environment has high moisture content.
- The conductivity & electrical resistance of the elements.
How dangerous is static discharge?
- The energy required that increases the risk of some products combusting can be very low. If sparks occur due to static electricity, these sparks can ignite flammable products. These sparks are not always visible to the naked eye!
- Static charging of materials is often very difficult to avoid. The risk can be reduced or prevented by keeping the electrical charge as low as possible by simply discharging the static electricity through the hose in a controlled method.
- For example: - a suction and discharge hose used on trucks always needs a connection with an earth cable and an approved earthing point. This is of the utmost importance because static electricity occurs in several places on the vehicle and must be discharged immediately. Therefore the suction and discharge hoses have to be conductive or antistatic at all times.
- It is also important to reduce the suction speed. The level of static build up created through a hose highly depends on the velocity of the medium that rubs against the hose or the tank liner.
Accidents caused by static electricity
Static Electricity is extremely dangerous and one of the main causes of industrial fires and explosions. Some of the most common factors linked to static related industrial accidents are:
- The increase in process or production speed
- The increased usage of more finer powders and granulates
- The trend to use more purified fuels
- The increased concentration of potentially explosive and flammable solvents, gasses and fine powders in the atmosphere.