Safety technical measures for closed fire area of

Technical safety measures for closed fire area of air shaft

at about 3:10 p.m. on October 11, 2008, the main return air roadway of air shaft found that smoke was leaking from the gap on the roadway side at the intersection of C1 through roadway and raw water warehouse roadway. After the leaders of the mine immediately organized the investigation of this situation, the preliminary analysis determined that it belonged to the gap formed between the goaf of the original small coal mine and the ground, causing spontaneous combustion of the coal seam, Because of its ventilation negative pressure, it infiltrates from the roadway of our mine. There is a large amount of carbon monoxide gushing out at the intersection of C1 crossing and raw water warehouse roadway, No. 13 hole and No. 7 hole, of which No. 13 hole is particularly serious. The leaders of the mine organized a meeting to study the solution and decided to adopt closed wall and grouting fire extinguishing measures for the fire area. In order to ensure the safety in the construction process, this safety technical measure is specially prepared

I. human organization

1. The mine manager, safety mine manager and production mine manager organize a leading group, and each mine manager personally directs the masonry and grouting of the closed wall in the air shaft in turn

2. Wushouquan, the leader of the air shaft, is responsible for the arrangement and allocation of construction personnel and material organization of the air shaft sealing wall masonry and grouting

3. The production department and the office organize manpower in the main adit to supply the materials required by the air shaft in time to ensure the normal construction

4. The safety department and safety supervisors visit the site in person every shift to urge workers to carry out construction in accordance with technical measures and the requirements of mine leaders

5. Weishouhua, the leader of Tongwei team, organizes and arranges the gas inspector to work with each shift, and checks the concentration of toxic and harmful gases such as gas and carbon monoxide in the construction site and area at any time

II. Safety technical measures

1. First, install a 11kw local test software outside the air shaft wellhead. It is impossible to use the ventilator. Connect the air duct to the No. 13 hole, dilute the carbon monoxide there, and reduce its concentration to the allowable range of construction operations

2. The first step is to build a sealing wall (No. 5 sealing wall) at the No. 13 hole. The surrounding of the sealing wall must be embedded more than 30 cm into the coal wall, and the gap of the sealing wall must be sealed tightly with cement mortar without leakage. And install the gas detection pipe on the back closed wall, where a total of two seals are made

3. Hang the portable carbon monoxide detector at the construction site of hole 13 to monitor the change of carbon monoxide concentration at any time

4. After the completion of the closed wall of No. 13 hole, electricians were sent to dismantle the pipeline from the second Shimen to the intersection of the general return air lane and the C1 crossing arch lane, which is an important base in the province. At the same time, two sealing walls (No. 3 and No. 4 sealing walls) of C6 coal seam water bunker roadway shall be made. Not only should the gas detection pipe be installed on the closed wall, which is contrary to the established concept of the majority of consumers, but also the drain pipe should be installed on the side of the water outlet (No. 3 closed wall), and the height of the drain pipe should be 50 cm from the bottom plate. The enclosed wall is made of double-layer cement bricks, with a space of 60 cm left in the middle and filled with yellow mud. The sealing wall must be embedded in the top, bottom and upper walls for 30 cm, and the gap is filled with cement mortar, so that the cement paste adhered to the boiler wall can be mixed and sealed tightly

5. When all pipelines from the second crosscut to the intersection of the general air return roadway and the C1 through layer masonry roadway are removed, the masonry of the sealing wall here (No. 1 and No. 2 sealing walls) shall be started immediately, and the drain pipe shall be installed on the No. 1 sealing wall. The technical requirements are the same as those of No. 3 and No. 4 sealing walls

6. At the arched roadway at the intersection of C1 crossing and raw water silo roadway, the existing smoke outlet shall be drilled and grouted within 5 meters in front and back

7. After all closed walls and grouting work are completed, the mine organizes personnel to conduct a comprehensive inspection, and the ventilation production of the whole mine is resumed after confirming safety

8. Construction diagram of closed fire area: