Most of the fires caused by mine construction are external fires. Therefore, it mainly introduces the prevention and rescue of fire caused by external fires and ground construction fires in mines.
(I) Fire prevention points on the construction site 1. The construction organization design, construction drawings and various construction techniques should meet the fire prevention requirements, as well as the erection of temporary building facilities and the storage of materials on the construction site.
2. The construction site should have a strict fire prevention system, and carefully implement and adhere to daily management and inspection.
3. Strengthen the care of fire-fighting locations. Strict welding, cutting, and safety management of welding and cutting operations; prohibiting open flame heating, strict management of electric heating appliances, and prohibiting ignition and fire in the fire zone.
4. Raise awareness of fire protection, strengthen management of pyrotechnics, strengthen prevention work for fires, and equip with necessary fire-fighting equipment as required; ensure safe and smooth fire-fighting passages.
5. Reasonable selection of building materials; special measures must be taken when using open flames in areas with fire hazards and appropriate approval procedures should be completed.
(II) Mine fire prevention points In addition to the above-mentioned construction site fire prevention requirements, mine construction fire prevention should also pay attention to the following issues:
1. In the mine wells and below, a strict fire prevention system must be established according to the specific conditions, and regular inspections;
2. The mine must be equipped with a fire pool and a downhole fire piping system on the ground. If the surface pool is shared with production and domestic water, special measures should be taken to ensure fire water. The underground and fire-fighting piping systems must be provided with branch pipes and valves every 100m, but the branch pipes and the door should be set every 50m in the belt conveyor lane.
3. All temporary building structural materials should meet the fire protection requirements. The layout of the facilities such as the Shishishan and the timber yard should comply with the safety distance regulations, and strictly prevent the fireworks wells; the wells, flammable and explosive materials such as explosives (explosives storage) , grease stores, etc., as well as the waste rock mountain, material yard and other places should have strict fire prevention measures and systems, with adequate fire equipment.
4. There shall be no fireworks or heating in the furnace within 20m near the wellhead room and the ventilation room in the industrial site. In the workplaces of electrical facilities such as substations and wellheads, safety inspections should be carried out regularly to prevent fires. In the underground and wellhead rooms, welding, gas welding and torch welding shall not be carried out; if it is necessary to weld in the main room, main air intake or wellhead room, safety measures must be made every time, and relevant regulations should be observed.
5. The connection between the wellbore, Pingtong and all levels and the bottom hole yard, the connection between the main winding lane and the main transportation lane and the return air lane, the underground mechanical and electrical equipment Tong room, and the front and rear ends of the belt conveyor in the main roadway are 20m each. In the range, it must be supported by non-combustible materials.
6. In the key places such as winch house, air compressor room, distribution substation, main ventilation machine room, lumber factory, charging room, etc., sufficient fireproof equipment and fire extinguishing sand must be arranged according to regulations; the underground belt conveyor must use flame retardant tape and set There are safety devices such as temperature control and automatic watering.
7. Underground blasting operations shall strictly implement the relevant safety regulations, operating procedures, and operational regulations, and strictly prevent blasting and fire.
8. The underground gunpowder distribution room, the bottom hole yard, the waiting room, the substation, the pump room, and the winch chamber shall be equipped with adequate fire sand and fire extinguishers as required, and the corresponding electromechanical copper room shall be equipped with fire doors as required.
9. Downhole workers should take seriously and strictly prevent the occurrence of underground fires, carefully implement the operating procedures and operating procedures, and must also be familiar with the use of fire-fighting equipment, and be familiar with the storage location of fire-fighting equipment in their work areas.
(C) the relevant provisions of the Fire Prevention and mine construction 2011 State Administration of Work Safety issued the "construction of coal mine safety regulations >> AQ1083-201 1, the characteristics of coal mine construction, mine construction work on the anti-fire put forward strict, standardized The requirements have become a legal and important basis for guiding mine construction and fire prevention. The following is a list of important fire protection requirements related to mine construction.
1. It is strictly forbidden to use the bulb to heat and use the electric furnace.
2. No electric welding, gas welding and torch welding shall be carried out in the underground and wellhead rooms. If it is necessary to carry out work such as electric welding, gas welding and torch welding in the underground, roadway and wellhead rooms, safety measures must be made each time. If the project is contracted by a construction unit and approved by the person in charge of the construction unit, and contracted by two or more construction units, the person in charge of the construction unit shall approve and abide by the following provisions:
(1) Designate a person to be inspected and supervised.
(2) Within 10m of the roadway at the front and rear ends of the work site such as electric welding, gas welding and torch welding, it shall be supported by non-combustible materials, and a special person shall be responsible for spraying water. There should be at least 2 fire extinguishers at the above work sites.
(3) When welding, gas welding and torch welding are carried out in wellheads, wellbores and inclined roadways, it is necessary to receive Mars in a non-combustible material facility below the work site.
(4) The gas concentration in the working place such as electric welding, gas welding and torch welding shall not exceed 0.5%. Only when the top of the roadway and the supporting backing plate are accumulated within 20m near the inspection site, the operation can be carried out. .
(5) After the work of electric welding, gas welding and torch welding, the working place should be sprayed again with water, and a special person should check it on the working surface for 1 hour, and find the abnormality and deal with it immediately.
(6) When welding, gas welding and torch welding are carried out in mines where coal (rock) and gas (carbon dioxide) are at risk, all work in the danger zone must be stopped. In the sound chamber and roadway where coal seams or shotcrete are not used in the coal seam, welding, gas welding and torch welding are not allowed. High gas, coal (rock) and gas (carbon dioxide) prominent mines are not allowed to perform electric welding, gas welding and torch welding in the return air flow.
3. When exposing new coal seams, the construction unit must identify the spontaneous combustion tendency of the coal seam.
4. In the construction of coal seams that are prone to spontaneous combustion and spontaneous combustion, a self-ignition and fire prediction forecasting system must be established.
5. When constructing in coal seams that are prone to spontaneous combustion and spontaneous combustion, the roofing area that appears must be fireproofed in a timely manner and inspected regularly.
6. Anyone who discovers a downhole fire should immediately take all possible means to extinguish the fire, control the fire, and report to the dispatch room promptly, depending on the nature of the fire, the ventilation and gas conditions in the disaster area. After receiving the report of the underground fire, the dispatching room shall immediately notify the relevant personnel to organize the rescue of the personnel in the disaster area and carry out the fire fighting work according to the emergency plan.
On-duty dispatch and on-site areas, teams, and team leaders should evacuate all personnel in areas that may be threatened by fire according to the contingency plan and organize personnel to extinguish the fire. When the electrical equipment is on fire, the power supply should be cut off first; before the power is cut off, only non-conductive fire-fighting equipment should be used to extinguish the fire.
During the rescue personnel and fire fighting, special personnel must be designated to check for changes in gas, carbon monoxide, coal dust, other harmful gases and wind direction, air volume, and safety measures to prevent gas, coal dust explosion and personnel poisoning.
(I) Fire prevention points on the construction site 1. The construction organization design, construction drawings and various construction techniques should meet the fire prevention requirements, as well as the erection of temporary building facilities and the storage of materials on the construction site.
2. The construction site should have a strict fire prevention system, and carefully implement and adhere to daily management and inspection.
3. Strengthen the care of fire-fighting locations. Strict welding, cutting, and safety management of welding and cutting operations; prohibiting open flame heating, strict management of electric heating appliances, and prohibiting ignition and fire in the fire zone.
4. Raise awareness of fire protection, strengthen management of pyrotechnics, strengthen prevention work for fires, and equip with necessary fire-fighting equipment as required; ensure safe and smooth fire-fighting passages.
5. Reasonable selection of building materials; special measures must be taken when using open flames in areas with fire hazards and appropriate approval procedures should be completed.
(II) Mine fire prevention points In addition to the above-mentioned construction site fire prevention requirements, mine construction fire prevention should also pay attention to the following issues:
1. In the mine wells and below, a strict fire prevention system must be established according to the specific conditions, and regular inspections;
2. The mine must be equipped with a fire pool and a downhole fire piping system on the ground. If the surface pool is shared with production and domestic water, special measures should be taken to ensure fire water. The underground and fire-fighting piping systems must be provided with branch pipes and valves every 100m, but the branch pipes and the door should be set every 50m in the belt conveyor lane.
3. All temporary building structural materials should meet the fire protection requirements. The layout of the facilities such as the Shishishan and the timber yard should comply with the safety distance regulations, and strictly prevent the fireworks wells; the wells, flammable and explosive materials such as explosives (explosives storage) , grease stores, etc., as well as the waste rock mountain, material yard and other places should have strict fire prevention measures and systems, with adequate fire equipment.
4. There shall be no fireworks or heating in the furnace within 20m near the wellhead room and the ventilation room in the industrial site. In the workplaces of electrical facilities such as substations and wellheads, safety inspections should be carried out regularly to prevent fires. In the underground and wellhead rooms, welding, gas welding and torch welding shall not be carried out; if it is necessary to weld in the main room, main air intake or wellhead room, safety measures must be made every time, and relevant regulations should be observed.
5. The connection between the wellbore, Pingtong and all levels and the bottom hole yard, the connection between the main winding lane and the main transportation lane and the return air lane, the underground mechanical and electrical equipment Tong room, and the front and rear ends of the belt conveyor in the main roadway are 20m each. In the range, it must be supported by non-combustible materials.
6. In the key places such as winch house, air compressor room, distribution substation, main ventilation machine room, lumber factory, charging room, etc., sufficient fireproof equipment and fire extinguishing sand must be arranged according to regulations; the underground belt conveyor must use flame retardant tape and set There are safety devices such as temperature control and automatic watering.
7. Underground blasting operations shall strictly implement the relevant safety regulations, operating procedures, and operational regulations, and strictly prevent blasting and fire.
8. The underground gunpowder distribution room, the bottom hole yard, the waiting room, the substation, the pump room, and the winch chamber shall be equipped with adequate fire sand and fire extinguishers as required, and the corresponding electromechanical copper room shall be equipped with fire doors as required.
9. Downhole workers should take seriously and strictly prevent the occurrence of underground fires, carefully implement the operating procedures and operating procedures, and must also be familiar with the use of fire-fighting equipment, and be familiar with the storage location of fire-fighting equipment in their work areas.
(C) the relevant provisions of the Fire Prevention and mine construction 2011 State Administration of Work Safety issued the "construction of coal mine safety regulations >> AQ1083-201 1, the characteristics of coal mine construction, mine construction work on the anti-fire put forward strict, standardized The requirements have become a legal and important basis for guiding mine construction and fire prevention. The following is a list of important fire protection requirements related to mine construction.
1. It is strictly forbidden to use the bulb to heat and use the electric furnace.
2. No electric welding, gas welding and torch welding shall be carried out in the underground and wellhead rooms. If it is necessary to carry out work such as electric welding, gas welding and torch welding in the underground, roadway and wellhead rooms, safety measures must be made each time. If the project is contracted by a construction unit and approved by the person in charge of the construction unit, and contracted by two or more construction units, the person in charge of the construction unit shall approve and abide by the following provisions:
(1) Designate a person to be inspected and supervised.
(2) Within 10m of the roadway at the front and rear ends of the work site such as electric welding, gas welding and torch welding, it shall be supported by non-combustible materials, and a special person shall be responsible for spraying water. There should be at least 2 fire extinguishers at the above work sites.
(3) When welding, gas welding and torch welding are carried out in wellheads, wellbores and inclined roadways, it is necessary to receive Mars in a non-combustible material facility below the work site.
(4) The gas concentration in the working place such as electric welding, gas welding and torch welding shall not exceed 0.5%. Only when the top of the roadway and the supporting backing plate are accumulated within 20m near the inspection site, the operation can be carried out. .
(5) After the work of electric welding, gas welding and torch welding, the working place should be sprayed again with water, and a special person should check it on the working surface for 1 hour, and find the abnormality and deal with it immediately.
(6) When welding, gas welding and torch welding are carried out in mines where coal (rock) and gas (carbon dioxide) are at risk, all work in the danger zone must be stopped. In the sound chamber and roadway where coal seams or shotcrete are not used in the coal seam, welding, gas welding and torch welding are not allowed. High gas, coal (rock) and gas (carbon dioxide) prominent mines are not allowed to perform electric welding, gas welding and torch welding in the return air flow.
3. When exposing new coal seams, the construction unit must identify the spontaneous combustion tendency of the coal seam.
4. In the construction of coal seams that are prone to spontaneous combustion and spontaneous combustion, a self-ignition and fire prediction forecasting system must be established.
5. When constructing in coal seams that are prone to spontaneous combustion and spontaneous combustion, the roofing area that appears must be fireproofed in a timely manner and inspected regularly.
6. Anyone who discovers a downhole fire should immediately take all possible means to extinguish the fire, control the fire, and report to the dispatch room promptly, depending on the nature of the fire, the ventilation and gas conditions in the disaster area. After receiving the report of the underground fire, the dispatching room shall immediately notify the relevant personnel to organize the rescue of the personnel in the disaster area and carry out the fire fighting work according to the emergency plan.
On-duty dispatch and on-site areas, teams, and team leaders should evacuate all personnel in areas that may be threatened by fire according to the contingency plan and organize personnel to extinguish the fire. When the electrical equipment is on fire, the power supply should be cut off first; before the power is cut off, only non-conductive fire-fighting equipment should be used to extinguish the fire.
During the rescue personnel and fire fighting, special personnel must be designated to check for changes in gas, carbon monoxide, coal dust, other harmful gases and wind direction, air volume, and safety measures to prevent gas, coal dust explosion and personnel poisoning.
High Precision Machining is defined as a process of changing the dimensions or the performance of workpiece with machining facilities.
According to the temperature of the workpiece while in machining, high precision machining can be divided into cold working and hot working. Usually, machining under indoor temperature, and won't change cause chemical change or phisical phase change is named cold working. On the other hand, if under temperature, higher or lower than room temperature, which will lead to chemical changes or phase changes, it will be called as hot working.
For high precision machining, the machining tolerance can be up to 0.0001-0.001mm, the surface finish Ra can be 0.02-0.1um.
Machining precision is to describe the actual geometrical parameter of the part after machining, such as the size, the form, the position, comparing with the theoretical geometry parameter. The difference from these two parameters is the machining tolerance. The number of the difference show the machining accuracy, the bigger, the lower of the machining precision, the smaller, the higher machining precision.
High Precision Machining
High Precision Machining,Aluminum Alloy Diecasting,Precision Parts,Machining Parts
NINGBO ZHENHAI BOLANG METAL PRODUCT FACTORY , https://www.blcastings.com