The main volume of coal is mined underground using shearers. In modern shearers, auger actuators are mainly used, which are distinguished by the simplicity of design, manufacturability and reliability. However, in the process of separating coal from mass by cutting, the yield of fine grades is 40-50 % of the total production volume. Therefore, the search and development of technical solutions that provide an increase in the yield of large fractions in the process of coal mining with auger shearers is an urgent task. Traditionally, this problem is solved by increasing the thickness of the slices, which is achieved by installing cutters with a larger radial reach and increasing the shearer feed rate. An unconventional way to increase the cross section of slices by forming energy-efficient paired and group slices with mutual superposition of stress fields in the mass from the action of neighboring cutters is considered. The results of modeling the process of cutting coal confirm that an increase in the efficiency of destruction of the rock mass by the cutters of the auger executive bodies of the shearer can be achieved by a complex technical solution, including the formation of paired cuts and combined stress zones in the rock mass. As a result, the output of large fragments when cutting with paired cutters increases by 1.3-1.8 times compared with cutting with a single cutter.
The paper considers the cutting of brittle coals and rocks by a single cutter of a mining machine, in contrast to the generally accepted integral approach, different from the standpoint of the formation of successive elementary bursts that make up the cut. The process of the formation of an elementary bust in time is viewed as successive phases. Due to the complexity and multi-factor nature of the process, preference is given to experimental bench studies using reference cutters, isotropic materials, and real rock blocks. The bursting parameters values greatly influence the time of static forces action, the peculiarities of the formation of stress fields in the undercutter zone of the rock mass and the conditions for the emergence and development of main cracks in the near-cut zones during the cutting process. The accepted phase-energy method of analyzing the process, which most closely matches the structure of the studied process, revealed a more significant, than previously expected, effect on the cutting process, variability of cutting speed and potential energy reserve in the cutter drive. The paper discusses the possibility of purposeful formation of the parameters of elementary bursts. It describes new ways to improve the efficiency of cutting coal and rocks, in particular, reducing the maximum loads and specific energy consumption. It also considers the possibility of reducing the grinding of the rock mass and dust formation.
The paper examines the process of potash massive fracture with actuating devices of mining machines, having cross cuts, and discusses a test bench to study the influence of cut parameters on the formation of successive elementary spalls making up the cut.
The method is offered which allows to increase the wear resistance of bit bodies for continuous miners by means of their additional full hardening. This results in increasing the bit body hardness from 37-42 HRC up to 49-51 HRC, which must bring to increasing in wear resistance approximately of 25 %. The suggestion has been tested with a batch of bits spec. RKS-2 (РКС-2) in the mines of Vorkuta and have demonstrated an increasing in wear resistance compared with that of the bits which had not been exposed to an additional hardening.
It is shown that X-ray fluorescence method can be utilized to determine composition of steels used for manufacturing the rockbreaking tools. A conclusion is derived that one of the possible cause of low wear resistance of miner bits in «Vorkutaugol» is their bodies manufacturing from the steels, which do not meet the Mining Code specifications.
Modern means of complex mechanization of mining operations are effectively used only under favorable conditions. For this reason, the forced restructuring of the coal industries in many countries, which is accompanied by the closure of mines and entire basins, is not possible. We are searching for new alternative means of integrated mechanization of mining operations. Developed modular complexes of selective action are promising for the development of coal seams in difficult mining and geological conditions.
Принципиальная схема агрегата модульного исполнения для фронтальной отработки угольных пластов была разработана на кафедре горной электромеханики филиала ЛГИ в г.Воркуте ...
Датчик предназначен для непрерывного измерения с повышенной точностью и последующей регистрацией малых линейных скоростей и ускорений перемещений комбайна. Прибор встроен в корпус типового датчика УПДС ...
В систематическом контроле ресурса и его использовании в расчетах хозяйственной деятельности технических служб шахт заложен значительный резерв повышения эффективности эксплуатации очистных комбайнов ...
В лаборатории горных машин ЛГИ создан стенд и разработана методика испытания комбайнов перед спуском в шахту ...
Производительность добычных комбайнов во многом зависит от эффективности работы привода подачи, обеспечивающей перемещение машины во время работы и маневровых операций. Сложность конструкции, высокий класс точности изготовления и необходимость высокой надежности, особенно при работе в механизированных комплексах, требуют тщательной проверки привода подачи в сборе перед спуском машины в шахту. Такая проверка может быть проведена на испытательных стендах. Так, на рудоремонтном заводе им. В. И. Ленина комбината «Тулауголь» весьма тщательно проверяются отремонтированные приводы подачи Г-404 ...
