Common sense of mine hoisting transportation

1. What technical measures should be taken to improve mine transportation safety?

1) Improve the overwinding protection device.

Usually, the passenger car is equipped with two overwinding protection switches. One is installed on the depth indicator of the machine room, and the other is installed on the derrick. Due to untimely maintenance, the overwinding protection device sometimes loses its function.

Many mine impact travel switches have a slow action process. When the hoist is running at full speed, even if emergency braking is taken, the cage will continue to slide for more than 4~5m. Therefore, in addition to two overwinding switches, there must be automatic deceleration and wellhead speed limiter to achieve the goal. The newly improved overwinding device uses contactless induction switch as deceleration signal switch.

Adjust the deceleration point and dynamic braking intensity reasonably, and design the in-place switch at the same time. After many tests, the cage can stop smoothly at a distance of 1.7m from the wellhead under the continuous action of deceleration, in-place and overwinding switches.

2. What are the problems of self-study mine hoisting transportation?

Review of Mine Transportation Improvement 1. Why should the scraper conveyor be equipped with a chain tightening device? What kinds are commonly used? When installing the scraper chain, a certain pre-tightening force should be given so that the chain will not relax or accumulate at the minimum tension point during operation.

Type: 1. A section of scraper chain is fixed on the headstock, and the other end is wound on the headstock sprocket. Use the motor at the front of the car to reverse the sprocket and tighten the chain. When the motor stops reversing, stop the sprocket immediately with the braking device to prevent the chain from loosening. There are three main types: ratchet chain tensioner, friction wheel chain tensioner and brake disc chain tensioner. 2. It is basically the same as the first one, except that the chain is tensioned by a special hydraulic motor instead of a motor; 3. Use a special hydraulic cylinder to tighten the chain. 2. Briefly describe the reasons and specific provisions of the limit deflection angle of the winding hoist.

(1), if the deflection angle is too large, the wear of wire rope and crown wheel rim will be aggravated and the service life of wire rope will be reduced. If it is serious, the rope may break. Therefore, the "Coal Mine Safety Regulations" stipulates that the internal and external deflection angle should be less than130'. (2) In some cases, when the wire rope is wound on the drum, the phenomenon of "rope biting" will occur.

If the internal deflection angle is too large, the detached section of the rope intersects with the adjacent wire rope without separation, which is rope biting. Sometimes, although the internal deflection angle is not very large, it will "bite the rope" because of the small gap between the rope loops on the drum, the larger diameter of the wire rope or the larger diameter of the drum.

Biting the rope aggravated the wear of the wire rope. 3. What is the function of rope adjusting clutch? So that when the rope length is adjusted or the height is changed, the two drums can rotate relatively.

4. What are the parts of the vertical shaft anti-falling device? Vertical shaft fall arresters are generally composed of four parts: starting mechanism, transmission mechanism, grasping mechanism and buffering mechanism. Its working process is that when the rope is broken, the mechanism starts to move, and the rope grasping mechanism is driven by the transmission mechanism. The grab mechanism supports the cage on the bracket (guide rail or brake rope) in the shaft, and the kinetic energy of the cage falling is absorbed by the buffer mechanism.

Anti-falling device is an important part of cage. In order to ensure the safety of lifting personnel, Article 332 of the Coal Mine Safety Regulations stipulates: "Lifting personnel or single rope lifting cages (including manned skips) must be equipped with reliable anti-falling devices." The function of the anti-falling device is to support the cage stably on the guide or brake rope in the hoistway when the hoisting wire rope or connecting device breaks, so as to avoid the cage from falling into the bottom of the well and causing serious accidents.

5. How to improve the maximum traction of single-drum transmission device of belt conveyor? Page 74 6. What is the pre-tightening force of scraper chain? When the scraper chain is working, due to the stress, it will produce large elastic elongation, relax at the separation point of the driving sprocket, and even form accumulation, which will lead to accidents. In order to prevent this state, a certain tension is applied to the scraper chain during installation, so that it has pre-loaded elastic elongation. If this elongation is equal to the elongation that can be produced under rated load, relaxation will be avoided.

This tension is also called pre-tightening. 7. Briefly describe the content and replacement standard of periodic inspection of hoisting wire rope.

1 The new rope must be tested before use; In addition to the friction hoisting wire rope and the special wire rope for lifting materials in inclined shafts with an inclination angle below 300, the hoisting wire rope must be cut off regularly for testing during use. The wire ropes of lifting personnel or lifting personnel and materials shall be inspected once every 6 months from the date of stopping use; The wire rope specially used for lifting materials shall be inspected for the first time one year after it is stopped, and then every six months.

3. What are the problems of self-study mine hoisting transportation?

Review on "Mine Transportation Promotion"

1. Why should the scraper conveyor be equipped with a chain tightening device? What kinds are commonly used?

When installing the scraper chain, a certain pre-tightening force should be given so that the chain will not relax or accumulate at the minimum tension point during operation.

Type:

1. Fix a scraper chain on the headstock, and the other end is wound around the headstock sprocket. Use the motor on the headstock to reverse the sprocket and tighten the chain. When the motor stops reversing, stop the sprocket immediately with the braking device to prevent the chain from loosening. There are three main types: ratchet chain tensioner, friction wheel chain tensioner and brake disc chain tensioner.

2. It is basically the same as the first one, except that a special hydraulic motor is used instead of the motor to reverse the tight chain.

Tight chain;

3. Use a special hydraulic cylinder to tighten the chain.

2. Briefly describe the reasons and specific provisions of the limit deflection angle of the winding hoist.

(1), if the deflection angle is too large, the wear of wire rope and crown wheel rim will be aggravated and the service life of wire rope will be reduced. If it is serious, the rope may break. Therefore, the "Coal Mine Safety Regulations" stipulates that the internal and external deflection angle should be less than130'.

(2) In some cases, when the wire rope is wound on the drum, the phenomenon of "rope biting" will occur. If the internal deflection angle is too large, the detached section of the rope intersects with the adjacent wire rope without separation, which is rope biting. Sometimes, although the internal deflection angle is not very large, it will "bite the rope" because of the small gap between the rope loops on the drum, the larger diameter of the wire rope or the larger diameter of the drum. Biting the rope aggravated the wear of the wire rope.

3. What is the function of rope adjusting clutch?

So that when the rope length is adjusted or the height is changed, the two drums can rotate relatively.

4. What are the parts of the vertical shaft anti-falling device?

Vertical shaft fall arresters are generally composed of four parts: starting mechanism, transmission mechanism, grasping mechanism and buffering mechanism. Its working process is that when the rope is broken, the mechanism starts to move, and the rope grasping mechanism is driven by the transmission mechanism. The grab mechanism supports the cage on the bracket (guide rail or brake rope) in the shaft, and the kinetic energy of the cage falling is absorbed by the buffer mechanism. Anti-falling device is an important part of cage. In order to ensure the safety of lifting personnel, Article 332 of the Coal Mine Safety Regulations stipulates: "Lifting personnel or single rope lifting cages (including manned skips) must be equipped with reliable anti-falling devices." The function of the anti-falling device is to support the cage stably on the guide or brake rope in the hoistway when the hoisting wire rope or connecting device breaks, so as to avoid the cage from falling into the bottom of the well and causing serious accidents.

5. How to improve the maximum traction of single-drum transmission device of belt conveyor? Page 74

6. What is the pre-tightening force of scraper chain?

When the scraper chain is working, due to the stress, it will produce large elastic elongation, relax at the separation point of the driving sprocket, and even form accumulation, which will lead to accidents. In order to prevent this state, a certain tension is applied to the scraper chain during installation, so that it has pre-loaded elastic elongation. If this elongation is equal to the elongation that can be produced under rated load, relaxation will be avoided. This tension is also called pre-tightening.

7. Briefly describe the content and replacement standard of periodic inspection of hoisting wire rope.

1 The new rope must be tested before use; In addition to the friction hoisting wire rope and the special wire rope for lifting materials in inclined shafts with an inclination angle below 300, the hoisting wire rope must be cut off regularly for testing during use. The wire ropes of lifting personnel or lifting personnel and materials shall be inspected once every 6 months from the date of stopping use; The wire rope specially used for lifting materials shall be inspected for the first time one year after it is stopped, and then every six months.

4. What is the task of mine transportation promotion?

Transportation and hoisting is an important link in mine production. Its task is to transport the ore extracted from the stope to the ground concentrator or storage mine, to transport the waste rock to the waste rock yard, and to transport all kinds of equipment, equipment and operators needed for production.

In mine accidents, lifting transportation accidents account for a large proportion. Due to the harsh underground environment, narrow space, insufficient lighting and large rotating speed and kinetic energy of transportation equipment, it is easy to cause serious transportation accidents. Once a major accident occurs in the hoisting transportation system, the whole mine production will be paralyzed.

Therefore, it is very important to ensure the safety and reliability of the transportation system for the safe production of the mine. The transportation mode of mine hoisting is determined according to the mining method, development mode and economic and technical conditions of the deposit.

The main lifting methods of underground mining are: shaft lifting, inclined shaft lifting and roadway transportation.