In underground mining, hoist or winder is used to raise and lower the conveyance in the mine shaft. Modern hoists are typically powered using electric motors, historically with direct current drive using Ward Leonard control engine and solid-state converters (thyristors), but modern large hoists use variable frequency controlled alternating current. There are three main types of hoists used in mining applications:
Video Hoist (mining)
Keran drum
The drum hoist is the most commonly used hoist type in North America, South Africa, and South America. When using a drum hoist, the lifter cable is wrapped around the drum when the conveyance is lifted. Single-drum hoists can be used in smaller applications, but double-drum hoists easily allow the lifting of two conveyances in equilibrium (ie one jump raised while the second jump is lowered). The drum hoist is mounted on the concrete slab inside the hoistroom, the lifting rope runs from the drum, up to the top of the head frame, over the sheave wheels and below where they are connected to the conveyance (cage or pass).
Benefits
Drum hoists require less regular maintenance than friction hoists, because the hauling cables stay on the drum, and therefore have less downtime, and less sophisticated maintenance regimes. The drum hoist can continue to operate if the bottom of the shaft is submerged and the shaft depth is less required under the charge bag, unlike the friction hoist where such floods can cover the tail rope and so on. Because drum hoists do not have a tail cord, the lifting system is more suitable for slinging under a conveyance.
Losses
The hoist drum takes up more space than the friction crack for the same service because all the hauling cords should be accommodated on the drum when the hoist is fully lifted. Drum hoists require rapid fluctuations in power demand, which can cause problems if power is generated on the site rather than provided through the main power grid.
Maps Hoist (mining)
Friction Friction
Friction (or Koepe) hoists are the most common type of hoist used in Europe, Asia and Australia. A friction hoist was discovered in 1877 by Frederick Koepe. The friction hoist is mounted on the ground above the mine shaft, or at the top of the front frame. The friction hoist utilizes the tail and counterweight straps and does not have a fixed carrier strap to the wheels, but passes through it. The dikes and loads offset the need for the motor to overcome the load and lifting loads, thus reducing the required lift motor horsepower by up to 30%, with overall power consumption remaining the same. Friction hoists, unlike drum hoists, can and usually use multiple straps that give them larger load capacities, but because they require a greater safety factor, they are impractical for very deep axes.
Benefits
The new friction hoist is cheaper than the new drum hoist, and the delivery time for delivery may be shorter as there is more competition for manufacturing. The multi-rope friction hoist has a larger lift capacity than a drum hoist. The friction hoist is smaller in diameter than the drum hoist for the same service, making it easier to install and install than a drum hoist.
Disadvantages
A balanced friction hoist is not suitable for lifting from multiple loading pockets on different horizons in the shaft, and is generally unsuitable for internal shafts. Frictionless friction can not operate at normal speeds if the base of the shaft is flooded and water reaches the rope of the tail.
Blair multi-rope hoist
The multi-strap Blair hoist is a variation of a double-drum hoist. It is used in a very deep axis because the second drum cable is used to balance the main load.
Example hoist
- Example hoops
See also
- Lifter (device)
- Pulley
- Winch
- Hard Rock Miner Handbook
- Glossary of coal mining terms
Footnote
Source of the article : Wikipedia
0 Comments