Conveyor belt fire fire causes are many reasons for their own failure, caused due to external fire source. This paper analyzes the cause of the fire caused due to their own fault.
1.1 roller slip cause a fire
(1) on the drive roller covered rubber or wood liner liner wear serious, the friction coefficient decreases, causing slippage.
(2) drive roller surface moisture conveyor belt to slip, such as water coal.
(3) the handpiece buried coal led to the surface of the roller with the conveying of coal into between the friction coefficient decreases, causing the belt to slip.
(4) the tension force of the tensioning device is not enough, resulting in decreased traction, causing slippage.
(5) driven roller bearing damage stuck driven drum speed drops or does not turn, caused by the the relative conveyor roller slip.
Drive roller and a driven roller skidding drum surface temperature will quickly rise. According to statistics, about 40min slippage, the roller surface temperature of about 320 ℃, the conveyor belt will begin to smoke. 320 ° C has been burnt critical temperature. Therefore, the great drum slipping hazards, long slip can lead to lost
Send with fire, causing security incidents.
1.2
Roller cause a fire in recent years, by the roller does not turn lead to the roller temperature rise fire is one of the main coal conveyor belt fire. The rubber conveyor belt and coal run together on the roller, both a traction mechanism and bearing means, there is no relative movement between the coal conveyor belt, eliminating the frictional resistance of the coal with the belt. Roller built rolling bearing, heat-resistant conveyor belt and the roller is rolling friction, the running resistance is very small. However, due to downhole poor environmental conditions within the roller bearings easily into the coal dust, coal dust will cause the bearing stuck. Conveyor belt in the card after the death of the roller surface friction run, makes the roller temperature rises. It has been observed, roller friction conveyor belt fire after shutdown. Prior to shutdown, the belt to 1 ~ 3trds speed running, a fixed point on the conveyor belt and the roller surface of the contact time is shorter, the conveyor belt the temperature rise is small, Moreover, the airflow generated by the conveyor belt during operation can also be reduced ADS temperature of the roll surface. Therefore, during normal operation, even if there is friction, the conveyor belt is also difficult to fire. After the shutdown, the next roller stops rotating, the roller does not turn the main reason is to cause a fire. Roller does not turn around the general area of ​​the pulverized coal, pulverized coal surrounded by the roller cooling conditions will deteriorate, thus giving rise to fire, especially in easy to sprinkle coal unloading roller at the tail drum under the roller.
1.3 drum friction test of necessity
A so-called drum friction test, that is, the conveyor belt sample by roller friction test, any of its parts can not occur flame and flameless combustion, and the roller surface temperature of not greater than 325 ° C. Conveyor belt sample was mounted on the roller friction test apparatus, the upper and lower coverage levels were tested in still air, and the flowing air, the tension of 343N was applied during the test, the speed of the drum to (200.4-5) r / min rotational direction leaving the fixed end of the specimen. If the conveyor belt sample fracture within 60min, stop test, if not break to continue the pilot to stop 60min. During the test, the test should adhere to the scene of the test, the sample was observed at any time flaming combustion and flameless combustion, recorded the highest temperature of the test time and the surface of the roller. The roller friction test is to simulate the harshest environmental conditions during operation of the belt conveyor, i.e. a conveyor belt with steel roller. Simple direct friction belt can not combustion with flame and flameless combustion occurs. Retardant conveyor belt roller friction test point of view, the whole flame retardant fabric conveyor belt smoke in the laboratory temperature is about 220 to 250oC, the temperature of the wire rope flame retardant conveyor belt smoke about 250 to 280oC, and no flaming combustion and flameless combustion phenomenon. The temperature exceeds a predetermined value reached 360oC and even higher temperature, but can also occur with combustion phenomena. It is noteworthy that in this whole flame retardant fabric conveyor belt and steel cord retardant conveyor belt ignition temperature of 280300 ° C and 320 to 340oC, respectively, and the temperature is close to the the pulverized coal smoke temperature of 330 to 350oC, the ignition temperature of 420 ~ 440oC conveyor belt management, such as improper use can easily cause a fire. The fire is the worst accident in the belt conveyor, in the event, it will cause significant casualties and huge property losses. Therefore, before going down the conveyor belt drum friction test is very necessary.
2 Maintenance Management
2.1
Daily inspection, shorten the storage time, pay attention to their anti-high temperature, anti-corrosion, moisture and other periodic inspection. Prior to use to send the relevant units to be tested, to ensure that the conveyor belt used to meet the "Coal Mine Safety Regulations" and the relevant technical standards.
2.2
Conveyor check each drum rotation flexibility, fasteners firmly, bearing lubrication; the body roller should be complete, flexible rotation; H frame, beams should be smooth, without skew phenomenon; tensioning device should be complete, appropriate tension , the conveyor belt does not slip; cleaning device work well, especially uninstall the roller and the tail at the drum cleaning device, make the cleaning of the belt surface float coal, and other debris.
2.3
Protection device, conveying confidential installation temperature, speed, smoke, pile of coal and other protective devices, the device should be sensitive and reliable, problems in a timely manner in order to shut down, narrow the scope of the accident.
2.4
Improve the surrounding environment, in order to improve the surrounding environment, it is necessary to reduce roadway watering, try to make the water spray flow along the borehole wall, if necessary, waterproof sealing, grouting or plugging engineering measures. Mainly for acid mine water to prevent, avoid acidic water droplets fall on the conveyor belt. Roadway to keep clean, especially under the conveyor belt of the conveyor belt machine at the end slime frequent cleaning to ensure normal operation of the bottom roller.