Assessment of operational reliability of quarry excavator-dump truck complexes

The method proposed in the article is based on the mathematical apparatus for quantitative assessment of the reliability of majority schemes of structural redundancy of transport processes, which provide the availability and usage of several backup delivery channels in the transport process in case of any malfunction. The principle of multi-channel haulage is commonly used in quarries for transportation of overburden and minerals from benches by dump trucks, when excavators and dump trucks performing cyclic operations function as a single excavator-dump truck complex. This pattern of work significantly increases the likelihood of fulfilling the daily plan for transporting rock mass due to the redistribution of dump trucks between mining and overburden excavators in the event of failure of one or more units of mining and handling equipment. The reliability of excavator-dump truck complexes is assessed in three stages: initial data collection for mathematical modeling of excavator-dump truck complex performance; solving the problem of optimizing the distribution of dump trucks between excavators, ensuring maximum productivity of the excavator-dump truck complex; assessment of the reliability of its work depending on the probability of fulfilling the daily plan for the transportation of rock mass. The proposed method is implemented as part of a computer program and makes it possible to automate the operational management of the process of transporting rock mass in a quarry using a mobile application. The developed guidelines can be used for any quarries with automobile transport, regardless of the type of mineral extracted, the mining method, the loading pattern, the capacity of the excavation and loading equipment fleet, and the capacity of operated dump trucks

РЕСУРСЫ ПРОИЗВОДИТЕЛЬНОСТИ ЭКСКАВАТОРНО-АВТОМОБИЛЬНОГО КОМПЛЕКСА

The problem of defining of the productivity of excavator and truck complexes is especially important for open-cast mines. Different technologies are used for mining, depending on capacity and depth of occurrence, volumes of extraction of the rocks. Frequently the less expensive costs are ensured by the variants of extraction and loading of the minerals by excavators of cycle action and by further carriage by dumptrucks from the stripping front to the storehouse or to the mine dump. The studied scientific task is by its nature rather a transport problem as it is solved via optimization of transportation processes. The authors substantiate a method of calculation of productivity of excavator and truck complex containing dump-trucks of small capacity (less than 30 tons) and excavators with small capacity bucket (less than 2 cubic meters). The nomogram of productivity of excavator and truck complex, achieved on the basis of well-known study methods and calculation techniques, can be applied first of all at the stage of construction of open-cast mines. The use of the suggested instruments of the control of overburden transportation efficiency will help to adjust the plans of mining at Miheevsky mine and to reduce prime cost of copper ore extraction.Проблема определения производительности экскаваторно-автомобильных комплексов (ЭАК) является особо актуальной при разработке месторождений полезных ископаемых открытым способом. В зависимости от мощности и глубины залегания, а также объема добычи руды используют различные технологические схемы ведения горных работ на карьерах. Довольно часто наименьшие затраты при этом обеспечивают варианты, предусматривающие выемку и погрузку горной массы экскаваторами циклического действия и дальнейшую ее транспортировку автосамосвалами от добычного или вскрышного фронта на поверхность, соответственно на склад или в отвал. Рассматриваемая в статье научная задача, по сути, транспортная, поскольку она решается методами оптимизации транспортных процессов. Авторы обосновывают способ расчета производительности ЭАК, в составе которого задействованы автосамосвалы малой (до 30 т) грузоподъемности и экскаваторы с небольшой (до 2 м 3) вместимостью ковша. Полученная на основе известных методов расчета номограмма производительности ЭАК применима прежде всего в условиях строящегося карьера.

FIRST TEST RESULTS OF RF GUN FOR THE RACE-TRACK MICROTRON RECUPERATOR OF BINP SB RAS*

Abstract A new electron source for the Race-Track Microtron Recuperator is being developed by BINP SB RAS. It will increase average beam current and brightness of synchrotron radiation. Instead of the static 300kV electron gun operated now we are developing RF gun with the same energy of electrons. This RF gun consists of RF cavity with a gridded thermo cathode mounted on the back wall. RF cavity is driven by a 60 kW generator with last stage equipped by GU101A tetrode tube. Operational frequency of the cavity is 90.2 MHz. It is equal to the second subharmonic of the Microtron RF system frequency. A set of low power electronics controls amplitude of the cavity voltage and its tuner. This system, including a diagnostics beam line, has been installed to serve as a test bench to test the RF cavity and for beam dynamics studies. In continuous regime the designed 300 kV voltages at the acceleration gap is obtained. This paper summarizes the first test results of the cavity in this configuration