Semi hopper storage with slotted outlet is a type of modern automated large-capacity storage. The criterion for selecting the main parameters can be taken as a minimum cost of construction of the warehouse, since the change in the length L and cross-section F of the stack has a relatively small effect on the operating costs.
Long-term practice of deep ore dumps shows that in their operation there are significant difficulties, especially in the harsh climatic conditions of the Arctic Circle ...
One of the progressive directions in the development of mechanization and automation of mine transport is the complete conveyorization of transport from the loading face to the bunkers on the surface. However, it is difficult to carry out complete conveyorization, because for one link of the transport scheme - along vertical shafts - has not yet developed a sufficiently economic and reliable method of conveyor transport ...
One of the urgent issues of operation of belt conveyor lines of the mining industry is the improvement of existing and finding new ways of cleaning conveyor belts ...
Widespread use of conveyor transportation in some cases is limited by the shortcomings of traction and load-carrying bodies of existing types of conveyors. Belt conveyors with rubberized fabric (cotton and synthetic) belt have a relatively small length per drive and short belt life. The disadvantage of belt conveyors with rubber tether belt is the high cost of the belt and its repair (amortization of the cost of the belt is up to 50% of the total cost of transportation). Belt-and-channel conveyors have a complex belt design and, accordingly, its cost is high. Belt-chain, slat and scraper conveyors have a small length per drive, low strength and very high weight of the traction body ...
Currently, the main types of traction organ of conveyors and elevators are chains and rubberized belt. The use of rope traction is limited by the lack of a convenient design of attachment of the working body (scrapers, plates, buckets) to the rope. The existing types of attachment require adjustment of the pitch when pulling the rope and special devices for passing the couplings on the drive pulley. Fastening of these devices should be systematically controlled, as tightening is carried out by bolts.However, the rope pulling device has a number of advantages in comparison with the chain one: 6-8 times less weight, lower cost, greater reliability in operation and durability. At the same time, the design of pulleys, especially drive pulleys, is characterized by complexity and therefore relatively unreliable in operation. Sheaves for ropes with clamping couplings have a number of significant disadvantages and in the industry are used to a limited extent.
Comparative indicators of transportation cost are the main factors influencing the choice of transportation method. In this regard, it is of great interest to develop the most convenient for practical use methodology for determining these indicators.Determination of the transportation cost indicator for each of the compared options by the method of conventional tabular calculations is a time-consuming and cumbersome process, as it requires preliminary technical calculation of each option and on its basis - the compilation of various estimates and financial calculations.
Transportation of minerals along vertical mine shafts is carried out mainly by skip hoisting. This type of lifting, being an intermittent transportation unit, has a number of disadvantages. The main ones are as follows: 1) the necessity of construction of intermediate tanks (reloading hoppers) in the near-borehole and on the surface, designed to mitigate the unevenness of lifting and transportation on the surface;2) the complexity of full automation of the lifting process due to the need to continuously change the mode of operation of the engine; 3) high specific energy consumption and increased installed power of the engine, caused by the inclusion of starting rheostats and the presence of peak loads at each cycle of lifting.
In the practice of design and operation of mine electric locomotive traction is very important is the correct solution of the question of choosing the size of the train. In modern production practice, the solution of this question is essentially reduced to the choice of the coupling weight of the electric locomotive. Indeed, in spite of the fact that theoretically the optimum train size can vary within wide limits with an interval equal to one car, the coupling weight of the electric locomotive is taken not as required by the calculation for this train, but the nearest to the calculated one according to the standard. The final size of the train is usually taken from the condition of the maximum weight of the train for the selected electric locomotive size. Since there are only three standard values of the coupling weight of rolling electric locomotives, the same coupling weight of an electric locomotive is inevitably adopted for a very wide range of optimal train sizes.
One of the widely used at present methods of calculation of belt conveyors consists in a preliminary calculation, the initial position of which is the approximately determined value of power on the drive shaft of the conveyor, and in the final calculation - the method of determining the tension in characteristic points of the contour of the traction body. In this method, the accuracy of the final calculation depends on the accuracy of determining the preliminary calculation of the weight of a linear meter of belt. The practice of calculations shows that in a number of cases the error in preliminary determination of belt weight can reach a significant value, as a result of which the final calculation turns out to be insufficiently accurate.The main errors in the preliminary calculation are as follows: 1) the maximum tension of the belt is determined by a formula that is not valid for all cases encountered in practice; 2) the weight of moving parts of the conveyor is taken tentatively.
The weight of the train in the calculations of mine electric locomotive traction is taken by the lowest value determined from the conditions of the coupling weight of the electric locomotive, heating of traction motors and braking of the train. One of the above conditions in each specific case, depending on the main technical parameters of the electric locomotive and transportation conditions, is limiting and determines the size of the train. In the case under consideration, of the main technical parameters of the electric locomotive, the parameters of the coupling weight, continuous tractive force and continuous speed of the electric locomotive are of decisive importance. It is obvious that a rational ratio between the values of these parameters is of considerable interest, since it makes it possible, other things being equal, to allow a larger train size.
The introduction of automation into the main and auxiliary production processes is currently the most important direction of further development of mechanization of the Soviet mining industry. The workers engaged in this issue face two main tasks: 1) wide introduction into production of the achievements already available in this field, tested by the practice of work of individual enterprises; 2) finding ways to further expand the scope of application of automated methods of work and improve the equipment used for this purpose. Transfer to automatic operation of various still unautomated units of the complex of electromechanical equipment of mines requires solving a number of problems associated with the creation of special types of equipment, schemes and equipment for automatic control, monitoring and regulation. It is possible to automate in principle the operation of almost all mine mechanical installations, but the automation of some of them is achieved relatively easily, and others, even well-proven under conventional non-automatic methods of operation, - only with the use of very complex schemes and a large number of additional equipment and control equipment.
The existing method of calculating the traction body of mine rope pullers is similar to the method of calculating the rope of mine hoisting installations, developed by A. P. Herman. The method consists in determining the weight of a linear meter of rope by the maximum static load on the rope, including also its own weight, and in the selection of rope according to factory data on the basis of the weight found. The currently used method of calculating the traction organ of belt conveyors consists in the preliminary determination of power on the shaft of the drive drum conveyor, for which is tentatively taken the weight of moving parts of the conveyor, then sequentially determined: the traction force, the maximum tension of the belt, the required number of pads and, finally, the weight of a linear meter of belt. After the approximate weight of the belt is determined, the final calculation is repeated. With the current calculation methodology, the weight of the moving parts of the conveyor must inevitably be taken tentatively, since the exact weight of the belt is not known at the beginning of the calculation.
In the practice of production and design works there is often a need to determine the maximum length of a scraper conveyor per drive for specific transportation conditions. However, to date, this issue in the technical literature is not sufficiently covered. This article sets the task of establishing design formulas for determining the length of the conveyor per drive depending on the main parameters of the transportation unit - the strength of the traction body and the installed engine power.