Anti static measures for the hottest oil products

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Anti static measures for oil products

(I) generation of static electricity

during the sending, receiving, transportation and filling of oil products, the friction between oil molecules and between oil products and other substances will generate static electricity, and its voltage will increase with the intensification of friction. If it is not removed in time, when the electric voltage increases to a certain degree, it will jump between two electrified bodies (i.e. electrostatic discharge) and cause oil explosion and fire

the higher the electrostatic voltage, the easier it is to discharge. The voltage or the amount of electrostatic charge is mainly related to the following factors:

(1) the faster the oil filling flow rate is. The more intense the friction, the higher the electrostatic voltage

(2) the drier the air is, the harder static electricity is to dissipate from the air, and the easier the voltage is to rise

(3) the greater the distance between the oil pipe outlet and the oil surface, the more intense the friction between the oil and air, and the greater the agitation and impact of the oil flow on the oil surface, such as singular and plural, past tense, compound words, roots, etc., the higher the voltage

(4) the rougher the inner wall of the pipe, the more elbow valves it flows through, and the higher the electrostatic voltage it generates. When the oil contains water during transportation, the voltage generated by it is several times to dozens of times higher than that without water

(5) non metallic pipes, such as canvas, rubber, asbestos, cement, plastic and other pipes are more likely to generate static electricity than metal pipes

(6) the denser the oil filter grid is installed on the pipeline, the higher the electrostatic voltage is generated. The electrostatic voltage generated by silk felt filtration is higher

(7) when the air temperature is high (22 ~ 40 ℃), and the relative humidity of the three provincial key projects of technological innovation is 13% - 24%, it is very easy to generate static electricity

(8) under the same conditions, light fuel oil is easier to generate static electricity than lubricating oil

(II) methods to prevent electrostatic discharge

(1) all oil tanks, pipelines, loading and unloading equipment used for storing and transferring oil products must have good grounding devices, introduce static electricity into the ground in time, and regularly check the technical status of static grounding devices and test the grounding resistance. The grounding resistance of the oil tank in the oil depot shall not be greater than 10, and the following conditions of other equipment will be subject to paid maintenance services; The grounding resistance shall not be greater than 100 (including static electricity and safety grounding). The grounding electrode of the vertical oil tank is calculated according to the circumference of the oil tank, one group every 18m, and the grounding electrode of the horizontal oil tank is not less than two groups

(2) when loading oil into oil tanks, tank cars and railway tank cars, the oil delivery pipe must be inserted below the oil level or close to the tank bottom to reduce the impact of oil products and the friction between air

(3) in the season when the air is particularly dry and the temperature is high, pay particular attention to checking the grounding equipment, appropriately slow down the oil filling speed, and if necessary, water around the working site and the electrostatic conductive grounding electrode to improve labor productivity

(4) electrostatic discharge accidents are easy to occur at the beginning of oil transportation and loading and at the end of three quarters of the loading to the container. At this time, the flow rate should be controlled within 1m/s

(5) when loading oil, keep the oil outlet of the refueling pipeline in metal contact with the oil inlet of the tanker

(6) it is forbidden to pour light fuel oil into plastic barrels in the oil depot, and it is forbidden to pour light fuel oil in plastic containers in areas that affect the safety of the oil depot

(7) all personnel boarding the oil tank and engaged in fuel oil filling operations shall not wear chemical fiber clothing (except for the identified anti-static work clothes). Before entering the tank, the personnel on the tank should hold the unpainted oil tank ladder for a moment to guide the static electricity of human body

(III) setting of grounding device

(1) grounding wire

the grounding wire must have good conductivity, appropriate cross-sectional area and sufficient strength

flat steel with a thickness of not less than 4mm and a sectional area of not less than 48mm2 is often used for the grounding wire of oil tanks, pipelines and loading and unloading equipment; Oil tankers and oil tankers can use copper or aluminum wires with a diameter of not less than 6mm; Rubber pipes generally use stranded copper wires with a diameter of 3 ~ 4mm

(2) grounding electrode

the grounding electrode should use a steel pipe with a diameter of 50mm, a length of 2.5m and a pipe wall thickness of not less than 3mm, remove the rust and dirt on the surface of the pipe (do not make anti-corrosion treatment), dig a pit with a depth of about 0.5m, and vertically drive the grounding electrode into the pit bottom soil. The grounding electrode should be buried in places with high humidity and high groundwater level as far as possible. All contacts between the grounding electrode and the grounding wire shall be bolted or clamped to ensure good contact

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