"One Ventilation and Three Preventions" Safety Technology in Mine Ventilation System Design

"One ventilation and three preventions" refers to the abbreviation of mine ventilation, gas prevention, coal dust prevention and fire prevention management in coal mine safety production.

3. 1, ventilation management measures

3. 1. 1 air volume calculation of heading face

The required air volume of heading face should be calculated according to the need of eliminating gun smoke, gas (dust) and personnel breathing, and the wind speed should comply with the regulations. Choose the largest one as the basis for choosing local fans.

(1) According to the air volume required by the construction personnel in the heading face:

Q excavation = 4N = 4×20 = 80m/ min.

Where: n- is the maximum number of people on duty.

(2) Calculate the air volume according to the need of eliminating cannon smoke.

q dig =（7.8÷t）*√A（LS）/K =（7.8/20）*√ 13.57 *（900 * 13.26）/ 1.52 = 46545438+04。 205

Where: k coefficient (when 300 ≦ L

Among them, a- the amount of explosives blasted at the same time is kg, l- the longest ventilation distance of local ventilator in roadway excavation is m, s- the total section of roadway, and t- the smoke exhaust time, which is generally 10 ~ 20min.

(3), according to the need to eliminate gas calculation of air volume.

Q excavation = 100×q tile excavation× k excavation× (1-k drainage rate) =100× 0.5× 2× (1-0) =100 m3/min.

Where: Q tile tunneling-tunneling head absolute gas emission m/min, k tunneling-tunneling face gas emission imbalance coefficient, k tunneling =2. K drainage rate is taken as 0.

(4) Calculate the air volume according to the wind speed.

Q excavation shall meet the following requirements: 60VminS≤Q excavation ≤60 vmas.

60 minutes = 60× 0.25×14.4 = 216 m3/min.

60 vmams = 60×4× 14.4 = 3456 m3/min.

Q excavation is 4 14.23m3/min, which obviously meets the requirements of 60VmS≤Q excavation ≤240S.

Where: roadway s- clear section m2, VM- minimum wind speed m/s, and coal and semi-coal roadway VM = 0.25m/s..

3. 1.2 Selection of local fans (determine the size and quantity of local fans)

Table 2 Selection power of local ventilator kW112×128 2×152×18.52× 222× 302× 55 air volume m/ Min 200 350 350 400 450 500 600 750

3. 1.3 Provisions on Installation and Use of Ventilation Equipment and Facilities

(1), forced ventilation is adopted in the driving roadway, and the position of local ventilator is determined by the ventilation area. Local ventilator should be guarded by special personnel and listed. When the local ventilator stops running due to maintenance, power failure and other reasons, the personnel should evacuate, cut off the power supply and hang warning signs. Before restoring ventilation, the gas concentration must be detected by a gas surveyor to determine the way to restore ventilation. Local ventilator should be equipped with "three special and two locks" device.

(2) When installing the local ventilator, use the cable with rubber sleeve to introduce the motor for mine use. Three core wires are connected to the wiring screws in the motor junction box, and the fourth grounding wire is connected to the grounding screw in the box, and then the cover is covered.

(3) The local ventilator should be started several times in a row, and the power supply should be turned on for a short time at a time to ensure that the air pressure of the local ventilator increases gradually to prevent the ram from bursting.

(4), local ventilator Ann specialist regular maintenance, maintenance, ensure the normal operation of local ventilator.

(5) The air inlet of the local ventilator is not less than10m away from the return air lane, and the air outlet of the ram is not more than 5m away from the nose.

(6), ventilation area to do a good job of airflow control, to prevent the local ventilator circulating wind. A series of wind must formulate special safety technical measures and report to the mine manager for approval.

(7) The construction unit shall take good care of the ventilation facilities and equipment, and shall not damage them at will.

(8) The air door of ventilation system must be equipped with interlocking device to ensure the stability and reliability of the system.

3. 1.4 Provisions on air volume and wind speed of working face.

The air supply of the heading head is 414.23m/min, and the wind speed is kept between 0.25-4m/sec.

3. 1.5 install a clean ventilation, flame-proof water shed and compressed air for self-rescue.

(1). Install three purification spray devices at a distance of no more than 50m in the construction roadway.

(2) Flameproof water tank should be set in the range of 60 ~ 200 meters from the return air side. Its capacity is designed to be 200L/m cross-section water.

(3) The water tank should be installed horizontally (the long side is perpendicular to the direction of the roadway), the row spacing is 1~3m, and the length of the shed area should not be less than 20m. The distance between the edge of the same drainage bag and the roadway wall and support (beam) should not be less than100 mm. A layer of water bag should be added to the roadway supported by U-shaped shed and concrete, and the size of the water bag should meet the requirements between the edges. The distance between the bottom of the water bag and the roadway rail surface should be not less than 1.8m and not more than 2.6m；; The installation height of each drainage shed in the shed group should be consistent; When the roadway in the shed area needs a shed, its cross-sectional area and shape should be consistent with the roadway with a length of 20 before and after.

(4). The water shed should be installed in the straight section of the roadway. The distance between the water shed and the intersection, bend and slope of the roadway shall not be less than 50 meters.

(5) Installation and suspension mode of water bag: 1). The water bag should be freely hung on the hook, and the hook should also be freely hung on the support, and it is not allowed to be tied and tied to death; 2) The hook can be made of No.8 iron wire, and one end hung on the supporting member can be a hook. The hook at one end of the water bag should be straight, the hook angle is 60 (+5), and the length of the straight hook is 25mm；; 3) Hooks on both sides of the water bag should be relatively suspended.

(6) Maintenance of water shed: Check the quantity, suspension and water quantity of water bags in the water shed at least once a week, and replenish water, replace water bags and maintain or dismantle the water shed in time.

(7). Flameproof fuel tanks should be listed for management.

(8) Set a set of compressed air self-rescue system every 50m in the wind lane, and each set of compressed air self-rescue system shall be equipped with 5-8 sets of compressed air self-rescue devices. The nearest set of compressed air self-rescue system is 25-40m away from the head-on. Ensure the head-on excavation and emergency evacuation of all personnel in the roadway. The isolation self-rescuer is equipped with the same number. All equipment must be of good quality to ensure emergency use.

3. 1.6 gas management measures

(1). When the gas concentration in the return air flow of the heading head exceeds 0.8% or the CO2 concentration exceeds 1.5%, it is necessary to stop working, evacuate personnel and take measures for treatment.

(2) Electrical equipment cut off because the gas concentration exceeds the specified limit must be energized when the gas concentration drops below 0.8%.

(3) When the gas concentration in the return air reaches 0.8%, it is necessary to stop working, evacuate personnel, cut off the power supply and notify the operation department for processing. When the gas concentration in the airflow within 20 meters near the motor and switch position reaches 0.8%, it is necessary to stop running, cut off the power supply and evacuate people; When the concentration of Nevas is below 0.5% near the official fan switch 10 meter, the switch can be started manually.

(4). Underground air composition must meet the following requirements:

The oxygen concentration in the intake air of the heading face is not less than 20% and the carbon dioxide concentration is not more than 0.5%;

Table 3 The concentration of harmful gases shall not exceed the nominal maximum allowable concentration (%) of carbon monoxide and carbon monoxide specified in the table below.

Nitric oxide (converted to nitrogen dioxide NO2)

sulphur dioxide

Fluidized hydrogen H2S

Ammonia NH3 0.0024

0.00025

0.0005

0.00066

0.004 (5). When the gas concentration accumulated in the heading face and other tunnels with a volume greater than 0.5m reaches 2.0%, it is necessary to stop the work within 20m nearby, evacuate the personnel, cut off the power supply and handle it.

(6). When the concentration of carbon dioxide in the airflow of heading face reaches 65438 0.5%, it is necessary to stop working, evacuate personnel, find out the reason, formulate measures and deal with it.

(7). The mine must take measures to prevent gas accumulation from mining production management; When gas accumulation occurs, it must be handled in time.

The mine must have safety measures to restore ventilation, remove gas and send electricity after the main ventilator stops running or the ventilation system is damaged and the power is cut off. After normal ventilation is restored, all the places affected by the wind stoppage must be inspected by ventilation and gas inspectors and confirmed to be free from danger before they can resume their work. All roadways within 20m near the installation site of the motor and its switch must be inspected for gas, and the gas concentration can only be opened when it meets the requirements of this regulation.

Where the work is temporarily suspended, the wind shall not stop; Otherwise, you must cut off the power supply, set up fences, reveal warning signs, prohibit personnel from entering, and report to the dispatching room. When the concentration of Nevas or carbon dioxide in the shutdown area reaches 3.0% or other harmful gases exceed the specified concentration and cannot be treated immediately, it must be closed within 24 hours.

When the closed shutdown area is restored or the excavation work is close to these positions, the gas accumulated in it must be removed in advance. Safety technical measures must be formulated for gas drainage.

It is forbidden to work in areas where the wind stops or the gas exceeds the standard.

(8). Head-on portable gas instruments must be hung and turned on normally during tunneling construction, and gas surveyors should conduct gas patrol inspection at the site for not less than 3 times per shift.

3. 1.7 gas monitoring and management (gas sensor settings are shown in the figure)

(1), the alarm concentration of each probe: T 1≥0.8%, T2 ≥ 0.8%;

(2) Cut-off concentration of gas: T 1≥0.8%, t2 ≥ 0.8%;

(3) Power outage range: T 1 and T2 are not intrinsically safe in the driveway.

Electrical equipment

(4) Complex concentration: t 1

(5) The formula of rewiring: manual rewiring.

(6) The gas sensor is set as follows:

(7), installation and management

The gas sensor shall be suspended vertically, with a distance of not more than 300mm from the roof (top beam) and not less than 200mm from the side wall of the roadway.

The gas sensor must be calibrated regularly, and the standard gas sample and air sample must be used for calibration 1 time every 7 days. The gas overrun and power-off functions must be tested every 7 days. High outburst head must detect gas overrun and power-off function every day.

When installing the power-off control system, users should provide power-off conditions according to the requirements of power-off range, and take the monitor to the site to connect the underground power supply and cut off the power supply. Remove or change the power line and control line of telegraph equipment related to safety monitoring equipment, and repair the electrical equipment related to safety monitoring equipment. When it is necessary to stop the operation of safety monitoring equipment, it must be reported to the dispatching room and safety measures must be formulated before it can be carried out.

The gas inspector shall proofread and record the sensor data within the jurisdiction of each shift, check the appearance of sensors and cables, and report the recording and inspection results to the duty officer in ventilation area and dispatching station.

Sensors, cables, etc. Keep and use by the team leader. The sensor should not be directly facing the outlet of the ram, nor should it be sprinkled on the probe and line connector when sprinkling water. If there is any damage, report it to the duty room in ventilation area in time.

When shooting, move the sensor to a safe position 50 meters away from the head. After shooting, put it back and hang it as required.

Portable instruments should be hung on the front, not more than 300 mm from the roof (top beam), and should not be hung on the tuyere.

3. 1.8 fire prevention management measures

(1). Spontaneous combustion treatment: when a fire is found during construction, it depends on the nature of the fire; For the ventilation and gas situation in the disaster area, immediately take all possible methods to directly extinguish the fire, control the fire, cut off all power supplies at the same time, report to the dispatching room, and evacuate the personnel in the area threatened by the fire according to the disaster avoidance route. Take effective measures to deal with it in time. When electrical equipment is on fire, the power supply should be cut off first. Before cutting off the power supply, only non-conductive fire extinguishing equipment can be used to extinguish the fire.

(2) Fire prevention treatment of high roof caving: When roof caving occurs during tunneling, it must be filled with incombustible materials, and when roof caving is serious, it must be sprayed and sprayed. At the same time, manage the ventilation area by listing, check the gas and temperature, and report any abnormality immediately.

(3). Other fire prevention treatment

The abandoned blind roadway in excavation construction must be filled and closed.

When electrical equipment is on fire, the power supply should be cut off first. Before cutting off the power supply, only non-conductive fire extinguishing equipment can be used to extinguish the fire.

When driving through coal seam or constructing roadway in the bottom area of thick coal seam, it is necessary to put less load and put less light. Meanwhile, support must be positive. Reduce the empty top area.

3.2 Comprehensive dustproof management measures

(1). Install three shooting sprinklers at a distance of not more than 20m from the shooting head-on, which must be turned on before and after shooting, and the whole section can be turned off. Insist on sprinkling water before and after the gun to extinguish dust.

(2) Install three purification nozzles in the return air flow, with the spacing not exceeding 50m, and the distance between each nozzle is 3~5m.

(3) Water cannon mud must be used for blasting.

(4) Sprinkle water to wash the coal help to prevent coal dust accumulation (coal dust accumulation with a thickness of more than 2mm and a continuous length of more than 5m). Sprinkle water when loading coal.

(5) Strengthen personal protection, and wear dust-proof protective articles in the dust work area.

(6) Provisions on dust concentration in the workplace:

When the content of free silica in dust is greater than 10%, the maximum allowable dust concentration shall not be greater than 2 mg/m;

When the content of free silica in dust is less than 10%, the maximum allowable dust concentration shall not be greater than10 mg/m.

3.3 initiating explosive device management measures

(1) The electric detonator must be delivered by the blaster himself, and the explosives are specially delivered by users who are familiar with the Coal Mine Safety Regulations, and the blaster is responsible for supervision. After receiving the blasting equipment, it should be sent directly to the workplace for drug inspection and put into the box. No stopovers or littering.

(2) Electric detonators shall be numbered by special personnel, and the detonators issued must be numbered clearly. It is forbidden to distribute and use electric detonators without numbers.

(3) Before the electric detonator is sent to the blaster, it must be checked for full resistance one by one according to the specified requirements, and the crural line will be twisted into a short circuit. It is forbidden to issue electric detonators that are not conductive and have unqualified resistance.

(4) Blasters must store explosives and electric detonators in special gun boxes and lock them; It is forbidden to pile them together. The gun medicine box must be placed in a safe place, with intact roof and complete support, without spraying water, avoiding electrical equipment and warning lines.

(5) If it is necessary to cut cartridge, special tools must be used and the section should be flat. It is forbidden to cut the cartridge case or smash the cartridge case with other tools after the gun head is completed.

When extracting a single electric detonator from a string of electric detonators, the tube body shall not be pulled by hand or by hand. The electric detonators in the bundle should be arranged well, and the electric detonators should be pulled out by pulling the front foot line. After pulling out a single electric detonator, its crural line must be twisted into a short circuit.

(6) When assembling the primary explosive cartridge, the following provisions must be observed:

Must be carried out in a safe place, the roof is intact, the support is complete, there is no water spray, and electrical equipment and warning lines are avoided. It is forbidden to sit on the explosive material box and assemble the explosive cartridge. The number of assembled explosive cartridges should be limited to the number needed locally at that time.

When assembling the explosive tube, it is necessary to prevent the electric detonator from being subjected to vibration and impact, damaging the cornerstone and the insulation layer of the cornerstone.

Electric detonators must be loaded from the top of cartridge, and it is forbidden to use electric detonators instead of bamboo sticks. All electric detonators must be inserted into the cartridge. It is forbidden to insert the electric detonator obliquely in the middle of the cartridge or tie it to the cartridge.

After the electric detonator is inserted into the cartridge, the cartridge must be entangled with the foot line, and the foot line of the electric detonator must be twisted into a short circuit.

(7) The team leader of the working face shall be responsible for handing over the remaining explosives on duty to the blaster, putting them into the medicine box, locking them and reporting to the personnel on duty of the district team in advance. It is forbidden to pile up explosives together. The remaining explosive quantity must also be checked by the blaster and the construction team leader and signed by each other.

(8) The remaining detonators must be kept by the blaster himself and returned to the drug depot on duty. It is forbidden to hand over the remaining detonators to the next shift for use. Strict receiving and returning account cards must be established in the magazine and blasting area to eliminate loopholes. Detonators returned to the magazine must be tested for secondary conduction and full resistance before they can be issued, and records should be established.

(9) After blasting, the blaster, the gas measurer and the team leader of the production unit must * * * do a good job in gun inspection. After dealing with misfire hole blasting, the blaster must carefully check the misfire pile and collect unexploded remnants. It is forbidden to mix detonators into coal.

(10) If the personnel of the production unit or other relevant units find the lost explosives or bile, they must report it to the mine dispatcher in time, and it is forbidden to take it privately or keep it privately.

3.4 Prevention and control of water management measures

1, adhere to the law of "if you have doubts, you must explore, first explore and then dig".

2. Strengthen head-on ventilation to prevent harmful gases from escaping from the borehole. Each shift in ventilation area shall be equipped with a full-time gas surveyor on site.

3, in the process of construction, if you find abnormal signs such as sweating, red hanging, cold air, fog and water screaming, the roof drenching increases, the roof is heavy, the floor is protruding or cracked, if you find the color and smell of drenching water and muddy water, you must stop working, take measures and report to the operation department. If the situation is critical, all personnel in the water-threatened area should be evacuated. When evacuating people, people must be evacuated according to the route of disaster avoidance.

3.5 Safety and environmental management measures

(1). Whether the pipes and air ducts in the construction roadway are hung in good condition: feng shui pipes, air ducts, cables, monitoring lines, telephone lines, etc. Cable hooks should be used to hang neatly on both sides of the roadway, the ram should be hung on each ring, and the ram joint should be tight, and there should be no air leakage. Damaged or broken gate should be repaired or replaced in time.

(2) The "three noes" regulation shall be set for the construction roadway: there is no sundries, stagnant water and silt in the roadway, and the construction shall be carried out according to the requirements of civilized production standards.

(3) A construction drawing board shall be set in the construction roadway, which shall indicate the roadway section, layout, hole layout, construction technical parameters, road map for disaster avoidance and text description.

(4), the construction of roadway without roof leakage, no bracket wreck, roadway support intact. During the construction period, the support behind the working face must be checked regularly. If the shed is found to be leaking and deformed, it should be repaired in time (scaffolding or re-supporting), and the waist side and back roof should be re-erected.

3.6 Coal quality management

(1), strictly follow the roof and centerline, and it is strictly prohibited to destroy the roof and floor of coal seam at will. Coal eye layout should be reasonable, and the distance between surrounding coal eyes and roadway should be more than 200mm.

(2), there will be someone to pick the gangue, pick the gangue when loading manually, and fill the waist with the picked gangue.

(3) The excavation team shall set up a coal quality management team with the captain as the team leader, and the monitor on duty shall be responsible for the coal quality management. Each shift is equipped with 1-2 coal quality network members to report coal quality information to the coal quality management department.

(4) During the construction of semi-coal rock roadway, try to make the coal seam in the middle of the roadway section.

(5) When the thickness of coal seam is more than 0.5m, the coal and rock should be broken, repackaged and transported (when there is a waste dump system), or the waste dump should be filled. (6), using coal gangue packaging and distribution.