The generation of static electricity

The summary is very comprehensive; non-polar liquids tend to generate static electricity

Friction between the soft-sealing material and the metal material in the valve generates static electricity.

The original poster talked about the formation of static electricity. I wonder if there are any methods to prevent and eliminate it, as well as a list of chemicals that cause static electricity! :victory:

The second point is the analysis of static electricity generated during the pipeline transportation of oil products； Article 8 is the analysis of static electricity generated during the oil filling process

Anti-static measures: A necessary condition for static electricity to cause explosions and fires is the presence of static electricity； The static electricity has reached a level that causes discharge ； The existence of hazardous locations ； The ignition energy of the flammable substance is very high, or its concentration has reached the explosive limit. The necessary condition for an electrostatic shock is: the presence of static electricity ； It has reached the discharge state. The necessary condition for static electricity to disrupt production is that the amount of static electricity reaches a certain level. The basic conditions that lead to static electricity hazards are: the generation and existence of static electricity ； Charging and discharging of objects ； The presence of hazardous mixtures of combustible materials. Therefore, effective measures must be taken in response to the aforementioned basic conditions, such as reducing the generation of static electricity, guiding and dissipating existing static electricity, preventing static discharge, and controlling the concentration of hazardous mixtures of flammable substances, in order to prevent the occurrence of static electricity hazards. The measures to eliminate the hazards of static electricity mainly include grounding, leakage, neutralization, and process control methods. 1. Grounding method: Grounding is the simplest way to eliminate the hazards of static electricity. Grounding is mainly used to eliminate static electricity on conductors, and it is not suitable for eliminating static electricity on insulators. If there is static electricity on an insulator, grounding the insulator directly can easily lead to spark discharge. In areas where there is a risk of fire and explosion, to prevent accidents caused by static electricity sparks, the following grounding measures should be taken: (1) All equipment used for processing, storing, and transporting various flammable liquids, gases, and powders, as well as storage tanks, storage vessels, product transfer equipment, enclosed transportation systems, discharge equipment, mixers, filters, dryers, sublimators, adsorbers, etc., must be grounded. If the bag filter is made of textile-like materials, it can be threaded with wire and grounded. (2) The pipelines for oxygen, acetylene, etc. in the plant area and workshops must be connected into a continuous whole and grounded. All other pipes and equipment that can generate static electricity, such as air compressors, ventilation systems, and air ducts, especially those for local exhaust, must be connected into a continuous whole and grounded. If the pipe is made of a non-conductive material, wire should be wrapped around the outside or inside of the pipe, and the wire must be grounded. Metal joints on non-conductive pipes must also be grounded. (3) Auxiliary equipment or tools such as oil filling funnels, floating cylinder tops, and workstations should all be grounded. (4) The vehicle’s fuel tank should be equipped with a metal chain, the upper end of which is connected to the chassis of the fuel tank truck, while the other end is in contact with the ground. (5) In some locations with high levels of risk, in order to ensure reliable grounding of the rotating shafts, conductive lubricants or methods such as slip rings and carbon brushes can be used for grounding. The static grounding device shall be firmly connected and possess sufficient mechanical strength; it may share the same grounding system as other grounding purposes. 2. Leakage method: This method involves taking humidification measures and using antistatic additives to cause static charges to dissipate on their own from the insulators; it is known as the leakage method. (1) Humidification. Humidification is the process of increasing the humidity of the air. Humidity has a significant impact on static electricity leakage. As humidity increases, the surface resistance of insulators **decreases**, conductivity increases, and static electricity leakage is accelerated. Maintaining the relative air humidity at around 70% can prevent the accumulation of excessive static electricity. (2) Add antistatic additives. Antistatic additives are special auxiliary agents; when added to insulating materials that generate static electricity, they can increase the moisture absorption or ionic properties of these materials, thereby enhancing their electrical conductivity and accelerating the dissipation of static electricity ； Some additives possess good electrical conductivity on their own. (3) Use conductive materials or paper-insulated materials. Mechanical parts prone to static electricity should be made of conductive materials whenever possible. The inner layer of the container made of insulating material is lined with a conductive layer or metal mesh and grounded ； Using conductive rubber instead of ordinary rubber, etc., will accelerate the leakage of static electricity charges. 3. Neutralization method: The neutralization method is an important measure to eliminate the hazards caused by static electricity. The electrostatic neutralization method involves generating charged ions in areas where static electricity is concentrated, in order to neutralize that static charge. Electrostatic neutralization can be used to eliminate static electricity on insulators. Devices such as induction neutralizers, high-voltage neutralizers, and radiation neutralizers can be used to eliminate the hazards caused by static electricity. 3. Process control method: The humidification mentioned earlier is a measure to eliminate the risk of static electricity through process control. However, humidification does not control the generation of static electricity; rather, it accelerates the leakage of static charges to prevent them from accumulating to a dangerous level. From a process perspective, appropriate measures can also be taken to limit the generation of static electricity and control the accumulation of static charges. For example: use gear drives instead of belt drives to reduce friction ； Reduce the flow rate of liquids, gases, or dust to limit the generation of static electricity ； Maintain the proper tension of the conveyor belt to prevent slipping ； The pipes for pouring the liquid lead to the bottom of the container or are positioned close to the side walls, in order to prevent the liquid from hitting surfaces and splashing. There are also other measures that do not fall under the above four categories; for example, to prevent the hazards caused by static electricity on the human body, workers can wear anti-static work clothes and shoes. Measures such as ventilation and dust removal are also effective in preventing the risks associated with static electricity. Anti-static workbench. The hazards of static electricity. The main ways in which static electricity causes harm are as follows: 1. Fires or explosions. Fires and explosions represent the greatest dangers posed by static electricity. Although the amount of static electricity is small, it can easily discharge due to its high voltage, resulting in static sparks. In workplaces where flammable liquids are present, such as those involved in oil transportation, fires can be caused by static electricity sparks ； In areas with explosive dust or explosive gases and vapors, such as coal dust, flour, aluminum powder, hydrogen, etc., explosions can be caused by static electricity sparks. 2. Electric shock: Electric shock caused by static electricity can occur when a person comes into contact with statically charged materials, or when a person carrying static charge gets close to a grounded object; at such times, the static charge on the body can reach tens of thousands of volts. The severity of an electrostatic shock is related to the energy stored in the charged object; the greater the energy, the more severe the shock. The greater the capacitance or voltage of an electrostatic charge, the more severe the electric shock will be. The static electricity generated during the production process is very low, so the electric shock resulting from it is not fatal to humans. However, the human body may cause secondary accidents due to electric shock, falling, or tripping. Furthermore, electric shocks can also cause stress among staff, affecting their work. 3. Disruption of production: Static electricity can disrupt production or reduce product quality. In the textile industry, static electricity causes fibers to entangle and attract dust, reducing the quality of textiles ； In the printing industry, static electricity causes the paper fibers to become misaligned and unable to separate, affecting printing speed and quality ； In the photographic film industry, static electricity sparks cause the film to become sensitive, reducing its quality ； In the powder processing industry, static electricity causes the powder to adhere to equipment, affecting its filtration and transportation ； Static electricity can also cause electronic components to malfunction ； Interfering with radio communications, etc.

Anti-static measures are an important aspect of safety in the oil and gas storage and transportation industry. Floor 7 provides a detailed explanation of the hazards associated with static electricity as well as the measures to prevent it, which is very useful. In addition, relevant companies and facilities should establish and adhere to appropriate safety regulations; for example, employees working in oil depots are not allowed to wear shoes with nails or clothing made of synthetic materials, nor are they permitted to use mobile phones