A, what is the role of mine hoisting equipment?
Mine lifting equipment is the "throat" connecting the ground and underground. Its task is to lift coal and gangue along the shaft, and to lift personnel, materials and equipment. It is one of the important electromechanical equipment in mine production system.
2. What parts does the lifting equipment consist of?
Coal mine hoisting equipment consists of hoisting container (including cage, skip, mine car and man car), hoisting wire rope, crown sheave, derrick, loading equipment, unloading equipment and hoist (winch).
3. How does the vertical shaft hoisting system work?
Shaft ordinary cage hoisting. One cage is located on the bottom floor and the other cage is located on the wellhead platform. One end of the hoisting wire rope is connected with the cage, and the other end bypasses the crown block and is wound and fixed on the drum. When the motor drives the hoist drum to rotate, the underground cage rises. The car at one end is lowered, so that the car can reciprocate up and down along the guide rail in the shaft for lifting.
4. How does the inclined shaft hoisting system work?
For the inclined shaft train hoisting system widely used at present, the mine car is used as the hoisting container. One end of the wire rope is connected with several tramcar groups, and the other end is wound on the pulley of the crown block and fixed on the drum of the hoist. The rotation of the drum drives the tandem group to reciprocate in the shaft.
Train hoisting has single hook and double hook. According to the different forms of parking lots, it can be divided into dumping parking lots and flat parking lots. Single-hook tandem car lifting can be used for multi-stage lifting, which is generally used in parking lots. Flat yards are generally used for lifting double-hook tandem cars.
5. What is the function of wellhead safety door?
In order to prevent personnel, harvesters and other items from falling underground, safety doors must be set at the shaft wellhead, bottom hole and middle transportation lane. The wellhead safety door is interlocked with the lifting signal: the safety door is not closed, so the starting signal cannot be sent out; After the start signal is issued, the safety door cannot be opened; The safety door can only be opened when the cage is in place and a stop signal is given.
6. What is an anti-roll device?
When the hoist runs to the normal unloading position without stopping and continues to lift upwards, it is called overwinding. The serious consequence of overwinding is damage to the crown block and derrick. The broken wire rope causes the lifting container to fall, damages the shaft facilities and even causes casualties. When using a double-barrel hoist, when one hook is overwound, the other hook is too loose, and if you let go, it will cause a can squatting accident. Therefore, the hoist must be equipped with anti-overwinding device. When the lifting container exceeds the normal terminal stop position (or exit platform). 5 meters, must be able to automatically cut off power, and can make the safety brake (that is, the safety brake) play a braking role.
7. What is the function of the fall arrestor?
Vertical shaft cage and inclined shaft man-vehicle system must be equipped with anti-falling devices according to regulations, also known as broken rope protectors. When the hoisting wire rope connection device is broken, the cage broken rope protector can support the vertical shaft cage on the guide rail (or brake rope) quickly, automatically and accurately; The rope-breaking safety device for man-vehicle in inclined shaft can quickly brake the man-vehicle in inclined shaft to prevent it from continuing to slide down.
8. What is the function of ventilator?
The function of mine ventilator equipment is to continuously deliver enough fresh air to the underground, dilute and discharge all kinds of toxic and harmful radioactive gases and dust, adjust the climatic conditions in the mine, improve the working environment and ensure the safety and health of underground workers.
Nine, mine compressor equipment consists of which parts?
Mine air compressors are divided into fixed air compressors and mobile air compressors. The fixed air compressor consists of air compressor, drag device, air filter, airbag, pipeline and cooling system. The air compressor is directly driven by motor or belt. Before entering the compressor, the air should be filtered by the air filter to prevent dust and impurities from entering the cylinder and accelerate the wear of the cylinder. Compressed air enters the wind bag for storage, and then is sent from the wind bag to the underground gas consumption place through the pipeline. The cooling system is used to cool the air compressor.
10. What is the function of the air compressor?
All kinds of pneumatic tools used in mine production, such as pneumatic pick, pneumatic drill, pneumatic rock drill, etc., are powered by compressed air (air pressure for short), and air compressors are also used to supply air to the self-rescue system of air outburst mines. Mine air compressor is the equipment for producing and conveying compressed air. The machine that produces compressed air is called air compressor (air compressor or air compressor for short).
XI。 What is the function of drainage equipment?
In the process of mine production, atmospheric precipitation, surface water, aquifer water, fault water and old empty water (collectively referred to as mine water) will continue to flood into the mine, which will affect the safe production of the mine, so it is necessary to discharge mine water in time. Sometimes underground production also needs water, such as hydraulic coal mining, which requires water supply. Drainage and water supply are completed by drainage equipment.
Twelve, mine fixed drainage equipment consists of what parts?
Mine fixed drainage equipment is mainly composed of water pump, motor, suction pipe, drainage pipe, accessories and instruments installed on pipes and pumps.
Thirteen, what types of transportation equipment are there in coal mines?
At present, the main transportation equipment used in coal mine working face and transportation roadway are scraper conveyor, belt conveyor, electric locomotive, diesel locomotive and mine car.
Fourteen, scraper conveyor consists of what parts? How does it work?
Scraper conveyor (also known as valve) consists of four parts: head, fuselage, tail and auxiliary equipment.
The head is the transmission device of the conveyor, including the head frame, motor, coupling, reducer, head spindle and sprocket assembly; The fuselage consists of chute and scraper chain. Scraper chain consists of links and scrapers.
When working, the motor drives the scraper to run in the chute through the coupling, the reducer, the head spindle and the guide sprocket to convey the coal out.
15. What are the parts of the belt conveyor? How does it work?
Belt conveyor consists of belt, main roller, idler frame of tensioning device (including tensioning roller) and transmission device.
When working, the driving roller drives the belt to run through the friction between the driving roller and the belt. Coal or other articles are installed on the belt and run together with the belt to complete the conveying task.
16. What types of electric vehicles are there?
According to different power sources, there are two types of electric vehicles: battery type and overhead line type. In addition, there are diesel locomotives powered by diesel.
17. What's the difference between battery-operated and overhead electric locomotives?
The battery electric locomotive is powered by its own battery pack, and there is no need to set up a power supply device on the whole line; Overhead electric locomotive uses bare wires and tracks erected above the roadway as the power supply loop, so sparks often occur between the current collector and the overhead electric locomotive during driving, which is enough to ignite a certain concentration of gas and coal dust and cause an explosion. It is forbidden to transport overhead electric locomotives in mines during the period of coal tile outburst. In addition, whether it is a battery electric locomotive or an overhead electric locomotive, due to mechanical impact and other reasons, sparks will occur between the wheels and tracks of locomotives and harvesters. Therefore, the selection of electric locomotive transportation must comply with the relevant provisions of the remote.
18. What are the rules for laying tracks?
The track laying quality of the main transport roadway shall meet the following requirements:
Fasteners must be complete and firm, and consistent with the rail type. The gap between rail joints shall not be greater than 5mm, and the height and left-right error shall not be greater than 2mm. The height difference between the top surfaces of two rails in straight section and the height deviation between the top surfaces of outer rail and inner rail in curved section shall not be greater than 5mm. The upper deviation of straight line segment and widened curve segment is +5mm, and the lower deviation is-2 mm.. Gauge tie rods shall be arranged in curved sections. The specifications and quantity of sleepers shall meet the standard requirements, and the spacing deviation shall not exceed 50 mm. The granularity of ballast, the specifications and quantity of sleepers shall meet the standard requirements, and the sleepers shall be compacted. The ballast bed should be cleaned frequently, and there should be no sundries, floating coal and accumulated water. The same type of rail must be used on the same line. The model of turnout rail shall not be lower than that of line rail.
19. What are the safety facilities for inclined shafts with series hoisting?
(1) sports car protection device: it is installed in the inclined lane to prevent the vehicle from breaking rope and unhooking.
(2) Car stoppers: installed at the entrance of the upper leveling field, the upper leveling field near the slope change point and each field. Prevent harvesters from entering the parking lot by mistake or slipping into the well without hanging hooks.
(3) Car stop: it is installed at the place where the general plane is greater than 1 train length below the slope change point to prevent unconnected vehicles from going down.
(4) Signaling device: Each parking lot is equipped with a signaling device that can give a warning signal when the car topples.
The above-mentioned car stop device must be closed frequently, and it is not allowed to be opened until the car is released. In the inclined roadway which is also used for driving people and cars, when lifting people, the car blocking device and sports car protection device in the roadway must be always open and reliably locked.
20. What types of tunnel equipment are there?
There are two methods of roadway excavation in coal mine: comprehensive excavation method and drilling and blasting method. The comprehensive excavation method is suitable for coal and semi-coal rock roadway excavation, with fast excavation speed, high efficiency, low labor intensity, good production safety and technical and economic benefits, and usually adopts roadheader, loader, belt conveyor and other equipment; Drilling and blasting method is mainly used in hard rock roadway excavation, and it is the main method used in coal mine roadway excavation in China at present. The main equipment used is rock drill, scraper loader and crab claw loader. Because the scraper loader is easy to collide with rock (coal) and produce sparks when working, it is forbidden to use the scraper loader with wire rope traction in high gas roadway.
Twenty-one, pneumatic rock drill consists of which parts? What are their respective roles?
At present, the rock drilling equipment in China is mainly pneumatic rock drill. The appearance of pneumatic leg drill. Rock drill is composed of gas distribution, drilling, propulsion, powder discharge, lubrication and other control mechanisms. The tail end of the drill bit 1 is inserted into the drill sleeve of the drill bit, and the oiler 3 is connected with the pneumatic pipe 5, so that the lubricating oil is mixed with compressed air and brought into the drill bit to lubricate the moving parts. The pressure water for flushing the drilling hole is sent from the tail end of the drill bit by the water pipe and reaches the central hole of the drill bit through the water needle inserted in the machine. The air leg 6 supports the rock drill and provides propulsion.
22, fully mechanized mining face equipment is how to form a complete set?
Mechanized coal mining face, according to its mechanization degree, can be divided into ordinary mechanized working face (referred to as general mining) and comprehensive mechanized working face (referred to as fully mechanized mining). The equipment of common mechanized coal mining face is equipped with single drum shearer, flexible scraper conveyor, single hydraulic prop or friction prop and hinged top beam. The equipment of comprehensive mechanized coal mining face is supported by double drum shearer, flexible scraper conveyor and integral self-moving hydraulic support. In addition to drum shearer, plough is also a common coal dropping equipment in mechanized coal mining face.
23. How does the chain shearer work?
The invention is suitable for cutting the bottom groove in the gently inclined and extremely thin composite coal seam working face of small and medium-sized coal mines, which is convenient for cutting and dropping coal. It is a mechanized coal mining method for small and medium-sized coal mines.
Chain shearer is composed of traction part, electrical part and coal cutting part. The motor is a special explosion-proof motor, which is placed in the middle of the machine, and its two ends respectively extend out of the shaft to drive the traction part and the cutting part to work.
One end of the motor is connected with the traction part, and after being decelerated by the reducer, the rope drum is driven to rotate, and the wire rope is wound to drag the whole machine to move along the coal wall.
The other end of the motor is connected with the cutting part and drives the five-star sprocket and the chain to rotate through deceleration transmission; Under the action of sprocket, the chain rotates around the guide groove of the cutting disc, driving the pick to extend into the coal wall to cut coal.
Twenty-four, how to classify mine electrical equipment?
General electrical equipment for mining refers to non-explosion-proof electrical equipment special for coal mines, which has a solid shell and can prevent anyone from directly contacting charged bodies from the outside; Good sealing, can prevent water droplets from dripping vertically, and has moisture resistance; Cable lead-in device can prevent cable from twisting, breaking and damage; There is a mechanical interlock between the switch handle and the door cover. At the same time, there is a grounding device in the obvious place of the equipment shell, and it is marked with a grounding symbol. This kind of electrical equipment has an obvious permanent metal relief red sign "KY" on the obvious part of its shell, which can only be used in underground places where there is no danger of gas and coal dust explosion.
Twenty-five, what is mine explosion-proof electrical equipment?
According to the national standard GB3836. 1-200 explosion-proof electrical equipment for underground coal mine is called mine explosion-proof electrical equipment. This type of electrical equipment is suitable for low gas, high gas, coal dust and gas outburst and ejection areas in coal mines.
Twenty-six, mine explosion-proof electrical equipment what types? What sign?
See table for types and explosion-proof marks of various mine explosion-proof electrical equipment.
Type name
symbol
Type name
symbol
Type name
symbol
Increased safety type
e
Sand filling mold
q
Flameproof type
d
Sparkless type
ordinary
Intrinsically safe type
I
Pouring sealing type
m
Positive pressure type
P
Airtight type
H
Oil-filled type
O
Special type
s
27, what are the main power supply equipment in the mine?
Mine power supply equipment includes transformers, high voltage switches, low voltage switches, high and low voltage cables and various protective devices.
28. What are the requirements for mine power supply?
The mine should have double-loop power supply lines. When any circuit fails to supply power, the other circuit should be able to bear the full load of the mine. When a mine with an annual output of less than 60,000 tons uses single-loop power supply, there must be a standby power supply; The capacity of standby power supply must meet the requirements of ventilation, drainage and lifting.
No load can be connected to the two power lines of the mine.
29. What are the types of mining transformers?
Transformers are divided into power transformers and special transformers. Power transformers are divided into oil-immersed type and dry type. Mining oil-immersed transformer and mining flameproof dry-type transformer are special transformers with special requirements to adapt to the structure of coal mine production transformers. Mine oil-immersed transformer is a kind of mine general electrical equipment, which is used for overhead electric locomotive transportation roadway and electromechanical equipment chamber along the roadway in low gas mine or high gas mine. For township coal mines with small load, it is generally installed on the ground to supply power underground, and the flameproof dry-type transformer for mining is suitable for mines with dangerous gas explosion environment.
Thirty, what are the types of mine high voltage switch? What are the characteristics?
High voltage switch can be used as distribution switch or control protection transformer, high voltage motor or high voltage line. There are two types of high-voltage switches, namely, mine universal type and flameproof type. The mine universal type is suitable for low gas mines and installed in the substation at the bottom of the well. Mine flameproof type is suitable for all mining area substations in mines with gas or coal dust explosion danger and mines with gas explosion danger environment.
Thirty-one, what is the mine low voltage flameproof feed switch?
This switch is mainly used in the third line of underground low-voltage distribution, located at the outlet side of transformer, and used as 1 140V and 660V or 380V low-voltage distribution (feed) switches. There is an automatic protection device in the switch, which can automatically trip and cut off the faulty power supply when the line has current and leakage faults. The switch is suitable for mines with the danger of gas and coal dust explosion.
32. What are the types of mine cables?
Commonly used underground cables are divided into three categories, namely armored cables, plastic cables and rubber sheathed flexible cables for mining. Armored cable and plastic cable are mainly used for underground trunk power supply or negative fixed and semi-fixed equipment power supply, and mine rubber sheathed flexible cable is mainly used for mobile equipment power supply. New products used in coal mines must use flame-retardant cables with safety signs.
33. Can aluminum-cored aluminum-clad cables be used underground?
Aluminum core cable is widely used on the ground because of its low price. However, because it is an active metal, it is easy to burn at high temperature, especially when there is a short circuit fault, its arc burns gas and coal dust, causing combustion and explosion, so it is extremely unsafe. Therefore, it is forbidden to use aluminum-clad cables underground, and the use of aluminum-core cables is restricted: it is forbidden to use aluminum-core cables for underground low-voltage cables.
What are "chicken feet", "sheep tail" and "joint opening"?
"Chicken feet" means that the three-phase joints are wrapped with insulating tape, and there is no overall insulation, just like chicken feet. In this way, moisture can easily invade, which reduces the insulation resistance. "Sheep tail" refers to the end that is not connected with electrical equipment. The three phases are randomly wound with insulating tape, then wrapped with insulating tape and hung on the edge of the roadway, just like a sheep's tail. "Exposing joints" is more dangerous. After the three-phase core wires overlap each other, the underground power supply network does not even include insulation tape, so "chicken feet", "sheep tail" and "exposed joints" should be resolutely put an end to.
34. What is the flameproof of electrical equipment?
Flameproof means that when the explosive gas inside the shell of electrical equipment explodes, it will not cause the explosive gas around the shell to explode. All electrical equipment with this flameproof enclosure is called flameproof electrical equipment.
In order to realize the explosion-proof and explosion-proof performance of the flameproof enclosure, there are special requirements for the shape, material, volume and structure of the flameproof enclosure.
35. What is the main reason for the explosion of underground electrical equipment?
(1) Due to the serious corrosion of the flame-proof joint surface, there are large mechanical scars, and the connecting screws are not pressed tightly, so that the clearance of the flame-proof surface exceeds the specified value, and the explosion is lost.
(2) Due to external forces, such as smashing, pressing, squeezing, touching and other reasons, the candle-isolating shell is deformed or damaged; The connecting screws of the cover plate, the connecting nozzle and the junction box on the flameproof shell are broken and the threads are damaged; The connecting screws are not complete, the mechanical strength can not meet the requirements, and the explosion is lost.
(3) The connecting cable does not use qualified sealing ring or no sealing ring, and the unused cable hole does not use qualified blocking baffle or no baffle, resulting in explosion loss.
(4) The terminal post and the insulating sleeve are burned, so that the two cavities are connected, and the explosion-proof shell cannot explode due to the high pressure generated during the explosion inside the shell.
Thirty-six, what is the three urn protection of underground power grid?
The "three major protections" of coal mine underground power grid refer to: leakage protection, overcurrent protection and grounding protection. These are the three types of protection commonly possessed and used by underground electrical equipment and lines in coal mines in China.
37. What is leakage protection?
Leakage refers to the phenomenon that the insulation of underground electrical equipment or cables is reduced or partially damaged, so that current flows into the earth through insulation damage or into the earth through the equipment shell. Leakage may lead to electric shock casualties, electrical fires and gas and coal dust explosions. Leakage protection is to cut off the power switch immediately when the insulation capacity of the power grid is reduced or someone gets an electric shock to ensure safety.
38. What is overcurrent?
Overcurrent refers to the phenomenon that the current value flowing through electrical equipment or cable line exceeds its rated current when the circuit is short-circuited, overloaded or open-phase. Overcurrent may cause cables to catch fire, burn electrical equipment, cause fire, and may also lead to gas explosion. Over-current protection means that when the system has over-current phenomenon, it relies on the over-current protection device to act quickly to cut off the fault circuit and ensure safety.
39. What is protective grounding?
Protective grounding is a kind of protective device, which connects the metal that is not charged under normal circumstances, but may be charged when the insulation is damaged, with the buried electrode. The function of protective grounding is mainly to prevent personal electric shock accidents caused by the charging of the shell caused by equipment leakage.
Forty, what is the function of the comprehensive protector of coal electric drill?
Coal electric drill is a widely used drilling tool in coal mine. The comprehensive protector of coal electric drill provides AC power for coal electric drill, and has the functions of load, short circuit, leakage detection and remote power failure. When the coal electric drill is not working, the load cable is not charged.