How to do a good job of coal mine gas discharge

In the coal mine production shaft, the ventilation is stopped due to the main fan, the ventilation is stopped by the local fan, the air duct is disconnected at the air supply point of the local fan, the air cylinder is seriously damaged, the outlet end of the fan cylinder is too far from the working surface, and the local fan Motor burnout, power outage and overhaul, encountering goafs or old lanes, gas emissions, coal and gas outbursts, roadway falling, and unsealed fire areas will cause gas emissions due to gas accumulation. Production of coal mine gas explosion occurred on several occasions in the belt centralized control emissions from gassy mines during 2000, September 27 at the coal mine in Guizhou Shuicheng Mining Bureau wooden gully is because of the occurrence of gas and coal dust in the exhaust gas process The explosion caused a fatal death of 162 people. The lesson was very painful. The “Coal Mine Safety Regulations” and the original documents of the Ministry of Coal have many very specific regulations for gas discharge from mines, but why did gas accidents occur several times during the gas discharge from mines? The main reasons for analyzing multiple accidents include:

( 1 ) The discharge gas system is not sound and is not implemented.

( 2 ) The technical measures for discharging gas are not detailed or perfect.

( 3 ) Leaders of the mine did not pay attention and lacked on-site coordination and command.

( 4 ) Perform illegal operation of gas discharge workers.

Discharging methane in coal mine gas management is a very important task. It is a very rigorous job in terms of technology, operation, and management. A slight inadvertent accident may result in serious casualties. Therefore, there is a need for a set of scientific management methods. How to reduce the number of gas emissions and to avoid gas accidents in the process of gas discharge, according to some personal work experience and understanding of the "procedures" and related safety regulations, that should be done from the following aspects.

1 Try not to stop the wind and reduce the scope of the accumulation of gas roadway

The case of the 9 • 27 methane dust explosion accident in the Muchonggou coal mine of Shuicheng District . Use of this gully Lane 41116 rail coal heading face local fan for Taiwan 28kW wind, due to the large amount of gas emission, often overrun. The study add 1 station 28kW local fan air supply, when the power supply is connected to the new local fan 28kW, 41116 rail face power, stop the wind, only the face gas 10min reservoir concentration will be 3% or more, in In the subsequent process of gas discharge, gas explosions were caused by illegal discharge of gas, fan circulating air, and illegal dismantling of miner's lamps by site personnel. In the accident investigation, the view of the mine ventilation system drawing and investigation found that, with the 41116 rail adjacent roadway excavation face 41116 Cut in heading face local fan for the wind to two, one for 28kW wind turbine, a 230kW for the Tornado aircraft. The air ducts of the two headings meet at the installation of the wind turbines and at the fifth liaison area. If serious measures are taken, the new 28kW local ventilator will be connected to the power supply before the 41116 tunnel excavation face . Borrowing 41116 to cut a hole in the working face of a fan to supply wind to the 41116 tunnel heading face, the face will not accumulate gas. The workload is also not large, but it only replaces the two air ducts, which avoids the accumulation of gas in the 41116 tunnel excavation work surface and avoids the gas explosion accident.

In addition, on-site construction often has a phenomenon such as a broken blast tube, scraped air duct, scraped wind tube, etc., so that the work surface is breezy or windless, resulting in gas accumulation exceeding the limit. Sometimes, due to various reasons, the local fan will stop for a short period of time, resulting in a partial gas outflow on the working face. Some tile inspectors stop seeing the exhaust gas on the working face to stop the local fan and Fence the opening of the tunnel. On the warning signs, report on the mine waiting for the rescue team to discharge gas. From the work procedures of the tile inspectors, he has completed the prescribed tasks. However, as a result, local accumulation of gas from the breeze and windless roadway becomes the accumulation of gas in the entire roadway after stopping the wind, increasing the range and length of gas accumulation in the roadway. At the same time, the next step is to extend the time of gas discharge and increase the risk. Therefore, in case of the above circumstances, it must be based on the specific circumstances of the scene, in the case of evacuation of gas or the accumulation of roadway personnel, cut off the power of the case, in the gas barrier over the limit of the fence, set up an alert to maintain the normal operation of the local fan Waiting for emissions.

2 Establish a scientific and strict gas emission management system

( 1 ) The situation should be understood before gas emissions. When the mine needs to discharge gas, the person discharging gas shall first

The total length of the storage gas roadway, section, support, gas accumulation concentration, gas storage capacity, wind pipe laying, installation location of the fan, electrical equipment layout, ventilation system, etc. are fully understood. For some roadways that need to be sealed after closure, the mine ambulance team should conduct exploration first. Only by doing this can we be assured that the discharge of gas will proceed smoothly. ( 2 ) Strictly discharge gas approval procedures. The development of gas drainage measures is directly related to the ability to safely discharge gas, and no negligence is allowed. The research and development of gas drainage measures must be conducted by the chief engineer of the mine or the chief deputy chief of ventilation and convened a special meeting attended by the departments of ventilation, rescue teams, electromechanical, security inspection, transportation, road repair, relevant mining area teams, and mine dispatching (such as mines The construction organization of an external unit such as the Infrastructure Engineering Department must also participate in the joint research meeting to review the measures for discharging gas. After no objection, all the personnel participating in the research measure will sign and be approved by the chief engineer or the ventilation deputy general project. The phenomenon of separate signatures must be eliminated.

( 3 ) Gas discharge measures must be targeted to avoid formulation. As regards the discharge of gas, there is a clear provision in the "Procedure". Therefore, some measures have commonalities, but we must avoid stereotypes and avoid formulating. In participating in the national security inspection, it has been found many times that some mines have formulating measures for the discharge of gas, and they are not targeted, and even some of them have been used for seven or eight years. Bureau of wood still Watertown gullies 9 • 27 gas and coal dust explosion, for example. In the accident investigation, the inspection of the gas discharge measures found that the measures were not perfect, and some terms obviously did not meet the requirements of the “Regulations”. Several technical responsible persons were found to understand the situation and answered: how many years was this measure and measure was determined by the Mining Bureau. I I have been using this measure before taking office. As an engineering technician, he did not seriously study every safety technology measure, and he used the usual practice in his work, resulting in such a large casualty accident. Isn't this painful lesson worthy of consideration by every engineering technician?

3 What should be included in the discharge gas measures

( 1 ) The basic situation of gas discharge. Gas discharge location, time, length of accumulated gas roadway, gas concentration, tile

Absolute amount of emissions.

( 2 ) Partial ventilation. Fan type, fan installation position, fan diameter, wind pipe installed three links.

( 3 ) Power outage range. All return air systems from the discharge of gas sites to the discharge of surface wellheads shall be marked in detail

The location and name of the equipment, such as location, transformers, switches, and people responsible for power outages.

( 4 ) Withdrawal range. All the roadways through which the methane return air is discharged, that is, all the return air systems from the gas discharge location to the discharge floor wellhead and all the personnel who have been shut off from the site where the gas flow is discharged, must be arranged in a detailed manner.

( 5 ) Warning sites. All the mouths, passageways and ground wellheads that communicate with the gas return system.

( 6 ) Specific safety technical measures for gas discharge. In addition to the general requirements stipulated in the "Regulations", targeted measures should be formulated according to the conditions of the mine and site management.

( 7 ) Schematic diagram of the exhaust gas ventilation system. In addition to indicating the direction of the wind, ventilation facilities, it should also indicate the location of the gas discharge, the location of the fan installed, the location of the alert, and the contact point for communications.

4 Gas discharge operations

At present, in addition to the individual use of control equipment for the automatic discharge of gas, the more commonly used gas is the artificial control of air volume discharge. There are three specific types:

( 1 ) Bundling a fan with a rope to control the air volume discharge;

( 2 ) Disconnect the air duct, dislocate the virtual air and control the air volume discharge;

( 3 ) Set up a miner's lamp management system three-way control air volume discharge near the fan. Among the three methods, it is the best to set the three-way control of the air volume discharge, and the air duct dislocation is the virtual connection to control the air volume discharge, followed by the rope.

Sub-bundling air cylinders control the air volume to discharge, so the safety factor is relatively low. Especially when a fan with a large power is used, bundling the air cylinder with a rope easily breaks the rope, which results in uncontrolled discharge and may cause accidents.

It is forbidden to use the exhaust method that uses the blower switch button to open, stop, and stop, and prevent a wind blow.

5 Strengthen coordination and command of underground gas discharge

The production of gas discharged from mines involves a wide range of fields, especially the ventilation systems of some old mines are very complex, and some even involve several levels. At the same time, the discharge of gas requires ventilation, rescue teams, electromechanical, security, transportation, road repairs, and coordination of the relevant excavation teams. A slight oversight of this work will affect the normal operation of the discharge and delay the discharge time, while the gas accident may occur. Therefore, underground mines must have on-site mine supervisors (mine leaders) responsible for unified coordination and command.

6 Problems and suggestions that should be paid attention to in discharging gas

( 1 ) Special personnel must be arranged to check the wind turbines before and during the discharge of gas, and if necessary, to the mine

Ventilation facilities, such as the main air intake, are sent to special care.

( 2 ) In order to prevent downhole production units from blindly sending people into the gas discharge return flow area (sometimes the negligence of guards is occurring), before discharging gas, the mine dispatcher shall be responsible for notifying all units involved in the gas discharge on-site operation.

( 3 ) The location of the discharged gas should have a straight-through mine dispatching telephone, and temporary telephones can be set up if no fixed telephone is installed.

( 4 ) During the operation of gas drainage, it is difficult to continuously inspect the gas concentration at the air-pressure mixing area at the full wind pressure shall not exceed 1.5% . It is recommended to set up a station where the gas alarm concentration is adjusted to 1.5% by a professional . The portable gas alarm system allows gas concentration to be detected at any time.

( 5 ) Exhaust gas must be thoroughly inspected for the concentrated control of the coal mine belts discharged from the roadway to prevent the wind turbines from being disconnected or the roadway from falling to retain the gas. When checking, wear the instrument according to the relevant regulations and check other gas conditions.

( 3 ) Gas discharge measures must be targeted to avoid formulation. As regards the discharge of gas, there is a clear provision in the "Procedure". Therefore, some measures have commonalities, but we must avoid stereotypes and avoid formulating. In participating in the national security inspection, it has been found many times that some mines have formulating measures for the discharge of gas, and they are not targeted, and even some of them have been used for seven or eight years. Bureau of wood still Watertown gullies 9 • 27 gas and coal dust explosion, for example. In the accident investigation, the inspection of the gas discharge measures found that the measures were not perfect, and some terms obviously did not meet the requirements of the “Regulations”. Several technical responsible persons were found to understand the situation and answered: how many years was this measure and measure was determined by the Mining Bureau. I I have been using this measure before taking office. As an engineering technician, he did not seriously study every safety technology measure, and he used the usual practice in his work, resulting in such a large casualty accident. Isn't this painful lesson worthy of consideration by every engineering technician?

3 What should be included in the discharge gas measures

( 1 ) The basic situation of gas discharge. Gas discharge location, time, length of accumulated gas roadway, gas concentration, tile

Absolute amount of emissions.

( 2 ) Partial ventilation. Fan type, fan installation position, fan diameter, wind pipe installed three links. ( 3 ) Power outage range. All return air systems from the discharge of gas sites to the discharge of surface wellheads shall be marked in detail

The location and name of the equipment, such as location, transformers, switches, and people responsible for power outages.

( 4 ) Withdrawal range. All the roadways through which the methane return air is discharged, that is, all the return air systems from the gas discharge location to the discharge floor wellhead and all the personnel who have been shut off from the site where the gas flow is discharged, must be arranged in a detailed manner.

( 5 ) Warning sites. All the mouths, passageways and ground wellheads that communicate with the gas return system.

( 6 ) Specific safety technical measures for gas discharge. In addition to the general requirements stipulated in the "Regulations", targeted measures should be formulated according to the conditions of the mine and site management.

( 7 ) Schematic diagram of the exhaust gas ventilation system. In addition to indicating the direction of the wind, ventilation facilities, it should also indicate the location of the gas discharge, the location of the fan installed, the location of the alert, and the contact point for communications.

4 Gas discharge operations

At present, in addition to the individual use of control equipment for the automatic discharge of gas, the more commonly used gas is the artificial control of air volume discharge. There are three specific types:

( 1 ) Bundling a fan with a rope to control the air volume discharge;

( 2 ) Disconnect the air duct, dislocate the virtual air and control the air volume discharge;

( 3 ) Set up a miner's lamp management system three-way control air volume discharge near the fan.

Among the three methods, it is the best to set the three-way control of the air volume discharge, and the air duct dislocation is the virtual connection to control the air volume discharge, followed by the rope.

Sub-bundling air cylinders control the air volume to discharge, so the safety factor is relatively low. Especially when a fan with a large power is used, bundling the air cylinder with a rope easily breaks the rope, which results in uncontrolled discharge and may cause accidents.

It is forbidden to use the exhaust method that uses the blower switch button to open, stop, and stop, and prevent a wind blow.

5 Strengthen coordination and command of underground gas discharge

The production of gas discharged from mines involves a wide range of fields, especially the ventilation systems of some old mines are very complex, and some even involve several levels. At the same time, the discharge of gas requires ventilation, rescue teams, electromechanical, security, transportation, road repairs, and coordination of the relevant excavation teams. A slight oversight of this work will affect the normal operation of the discharge and delay the discharge time, while the gas accident may occur. Therefore, underground mines must have on-site mine supervisors (mine leaders) responsible for unified coordination and command.

6 Problems and suggestions that should be paid attention to in discharging gas

( 1 ) Special personnel must be arranged to check the wind turbines before and during the discharge of gas, and if necessary, to the mine

Ventilation facilities, such as the main air intake, are sent to special care.

( 2 ) In order to prevent downhole production units from blindly sending people into the gas discharge return flow area (sometimes the negligence of guards is occurring), before discharging gas, the mine dispatcher shall be responsible for notifying all units involved in the gas discharge on-site operation.

( 3 ) The location of the discharged gas should have a straight-through mine dispatching telephone, and no fixed telephones can be installed.

Temporary phone calls.

( 4 ) During the operation of gas drainage, it is difficult to continuously inspect the gas concentration at the air-pressure mixing area at the full wind pressure shall not exceed 1.5% . It is recommended to set up a station where the gas alarm concentration is adjusted to 1.5% by a professional . The portable gas alarm system allows gas concentration to be detected at any time.

( 5 ) Exhaust gas must be thoroughly inspected for the concentrated control of the coal mine belts discharged from the roadway to prevent the wind turbines from being disconnected or the roadway from falling to retain the gas. When checking, wear the instrument according to the relevant regulations and check other gas conditions.

The information in this article comes from the Internet and was reorganized and edited by China Rescue Equipment Network.