Electrostatic grounding < br means that the object is electrically and reliably connected to the ground through a conductor, antistatic material or other products, ensuring that the potential of the electrostatic conductor and the ground is close.
Causes of static grounding of isolated conductors:
When the static discharge line of the isolated conductor is not connected, the electrostatic charge will quickly accumulate to a high potential, and the voltage may even exceed 30kv. When the isolated conductor approaches another low-potential object, most of the energy generated will be flammable static electricity. The release of sparks greatly exceeds the minimum ignition energy of surrounding flammable substances. Once the flammable factors in the surrounding air reach a certain concentration, fire accidents may follow.
The flowing liquid generates static electricity 1. When a poor conductive liquid flows, static electricity is generated, which discharges between the liquid and the metal container, generating an electric spark.
2. When a good conductive liquid such as methanol and acetone flows into an ungrounded container, the container gets charge from the liquid, and an electrical spark is generated between the container and any nearby grounded metal.
Accident 1: A person carried a 10L metal can to pick up acetone. When he closed the valve on the acetone line, the acetone caught fire, and the fire spread to other parts of the building. Cause of the accident: The person wearing the shoes was unqualified and insulated. When he reached out to close the valve, the static electricity accumulated on the acetone, the barrel and the human body generated static sparks with the grounded valve and the acetone vapor was ignited.
Accident 2: A 2m rubber hose was used to add ethyl acetate to a metal tank. The metal tank was not properly grounded. The hose could not reach the bottom of the tank due to insufficient length, and the liquid splashed from a height of 0.6m. After several minutes of addition, an explosion occurred. The accident caused one death and one serious injury.
The best operating standard for explosion-proof situations1. First, the equipment must be grounded with grounding equipment such as grounding clamps 2 to ensure that the equipment is well grounded to discharge static electricity quickly and safely;
3. It is recommended to use the interlock function to ensure that the equipment is grounded before continuous operation (such as pumps);
4. The static ground resistance value for continuous monitoring is recommended to be below 10 ohms.