How to prevent and control the external fire in th

2022-09-23
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How to prevent and control the fire outside the mine

any uncontrolled combustion that occurs underground or on the ground and threatens the underground safety production and causes losses is called mine fire. The occurrence of mine fire has serious harmfulness, which may cause casualties, tight connection of mine production, huge economic losses, serious environmental pollution and so on

according to different ignition sources, mine fires can be divided into external and internal causes. External fire refers to the fire caused by external heat sources, such as open fire, explosion, gas and coal dust explosion, mechanical friction, circuit short circuit and other reasons. External fires mainly include electrical fires and belt conveyor fires. External cause fires are characterized by sudden occurrence and fierce attack. If they are not found in time, they may often lead to malignant accidents. Internal cause fire refers to the fire caused by the physical and chemical changes of coal (rock) layer or sulfur-containing mine under certain conditions and environment, and the accumulation of heat. The characteristic of internal cause fire is that the occurrence process is relatively long, and there are omens, which is easy to detect early, but it is difficult to find the exact location of the fire source center, and it is difficult to extinguish this kind of fire

(I) ignition source of mine external fire

from the implementation of electric valves in mines at home and abroad, its principle is roughly the same as that of deformation measurement. It refers to the case of mountain external fire with electric energy as the main energy source. It can be seen that its ignition source mainly includes the following aspects:

1. Open fire causes fire

open fire is the main ignition source of external fire. It includes carrying inflammables down the well; Smoking underground; Improper use of safety lamp or flame lamp; Bake or warm with a large bulb; Open fire caused by blasting or explosive burning and then turning 90 degrees to the left; Electric welding, gas welding and blowtorch welding are used underground; Gas explosion or gas combustion; The flame of the explosion of mineral dust or coal dust and the fire at the surface wellhead flows down the shaft

2. Fire caused by electrical equipment

such as fire caused by improper use of cables, wires, motors, electric drills, transformers, oil switches, etc; Fire caused by electric arc and spark, and fire caused by improper selection of fuse (piece)

3. Friction ignition

friction heating of the moving mechanism of mechanical equipment, causing nearby inflammables such as wood supports, wood blocks and lubricating oil to catch fire; The supporting roller of the belt conveyor does not rotate, and the friction produces sparks; The friction between coal mining machinery and rocks produces sparks or electrostatic sparks, etc

(II) preventive measures for external fires in coal mines

according to the relevant provisions of the coal mine safety code, the following measures should be taken to prevent external fires in coal mines:

1. No open flames

① fireworks and stoves are prohibited in the wellhead room and fan fan room within nearly 20 meters

② it is strictly prohibited to carry tobacco, matches, lighters and other kindling materials down the well, and smoking is strictly prohibited underground

③ electric welding, gas welding or blowtorch welding are not allowed in the wellhead room and underground; If the welding operation must be carried out underground, safety measures must be formulated and reported to the mine manager or the chief engineer for approval before it can be carried out. In addition, it is required to remove and remove the nearby inflammables in advance, prepare enough fire water, sand, fire extinguishers, etc., and check the concentration of gas and coal dust at any time

2. Control combustibles

① gasoline, kerosene or transformer oil are not allowed to be stored in the underground chamber. The lubricating oil and cotton yarn used underground must be operated in strict accordance with the steps specified in the instrument operation manual, and the cloth head must be stored in the iron cylinder and sent to the ground regularly for treatment

② it is forbidden to use black explosives underground, and only ammonium nitrate mining safety explosives and safety quilt explosives are allowed. Because the flame exists for a long time after the explosion of black explosives, there is a risk of igniting and detonating gas. It is not allowed to set off firecrackers underground. It is forbidden to use inflammables such as pulverized coal and gunpowder paper to replace gunpowder

③ the area near the belt conveyor should be cleaned frequently, the residual coal on the ground should be swept away, and the inflammables such as wood chips and gunpowder paper should be picked up; Try to use fire-resistant non combustible belts

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