The evolution of lifting equipment from mines and mine shafts originates with the advent of mining as such. The need to extract minerals to the surface forced engineers to develop special mechanisms and designs. The first systems of this kind were mechanical and set in motion by muscular effort. A modern mine hoist performs the same tasks, but is distinguished by high power, carrying capacity and the presence of effective security systems.
General information about mine lifts
The design of such shafts and the principle of operation resembles the function of a conventional elevator. As part of the lift, a cabin or platform on which the cargo is located is necessarily provided. In this case, there are many differences from conventional means of this kind. Firstly, the unit is oriented to work with large masses. Secondly, the very effect of the mechanisms that drive the platform or the cabin is different. In this sense, it is worth noting the separation by type of supporting infrastructure. There are mine mast lifts and freight models. The differences between them are in the nature of the technical implementation of the channel through which the site is moving. In the case of mast devices, it is assumed to use a rack, along which a rise in height occurs.
Classic cargo mechanisms involve movement along the channel in a structure that supports the cab on all sides. But in this case, due to the massiveness of the auxiliary infrastructure, the mine hoist is characterized by lower load-carrying capacities. Such complexes are more often used for lifting people and as emergency elevators.
Types of mine freight elevators
In addition to differences in approaches to the execution of the mine itself, hoists have many other features that determine the corresponding classifications. For example, recently there has been a departure from the technology of using single-rope systems. The use of several communication lines makes it possible to optimize mine shaft hoists, in terms of mass, by eliminating gearboxes. As a result, the cost of cars decreases. The mechanisms according to the type of rope mass stabilizers also differ. Today, the use of dynamic and static principles of balancing is practiced.
There is a classification for the purpose of lifts. In the category of trucks, one can distinguish the main channels through which the bulk of the minerals are extracted, and auxiliary. The second type is a mine lift, which can be used to work with the breed, and to accommodate people.
Lift device
Any installation for lifting through a mine shaft has a complex system that includes several interconnected units and assemblies. As a rule, the list of basic mechanisms includes a vessel, winding elements, a propulsion system and a set of pulleys. A separate group of devices provides interfacing between functional components. To implement this infrastructure, the mine hoist is equipped with the mentioned ropes, shaft shafts and couplings. The structural base is usually represented by a supporting platform, which may be flat or in the form of a pit. To control the design, special button posts are used.
Key Features
One of the main performance characteristics of freight elevators is the power of the power unit. In the latest versions, designers use electric motors with power up to 5 watts. Asynchronous electric motors are also common, the power potential of which varies on average from 1 to 2 watts. Such power indicators determine the speed regimes from 12 to 20 m / s. As for the possibilities of working with mass, a shaft-type hoist is capable of extracting cargo up to 70 tons. Models with higher load-bearing capacities are also known, but these are, as a rule, single units for specialized needs. In this case, the height of the trunk can reach 2 km.
Security systems
Since mining initially involves high risks, lift manufacturers pay special attention to safety systems. Without fail, modern designs are equipped with braking catchers. Such devices are activated in the event of a cable break. By the way, such risks largely determined the transition to multi-rope freight elevators. Mine complexes of this type are reliable and stable when lifting. Limit switches are also used as auxiliary safety systems , which block the launch of the site if the personnel did not fix the shutters and cabin doors. Automated systems also have special modes of operation in case of failure of certain mechanisms and controls.
Conclusion
The freight elevator today is the main type of technical tool that allows you to perform the extraction of minerals from the bowels of the earth. The only alternative to vertical systems is inclined shafts that transport rock and workers at an angle. Such designs are characterized by higher performance and reliability, but their implementation is not always possible. Therefore, a shaft-type vertical freight elevator remains the main transportation facility in mining. The efforts of most mining enterprises are aimed at the technological improvement of such complexes. Carrying components, control posts, and power mechanisms are also developing, on which the dynamic qualities of the lifts depend. Since the regular operation of mining equipment is expensive in terms of energy costs, engineers are also looking for more rational approaches to the implementation of propulsion systems.