An important importance in the selection of hydraulic drive for mining machines is the development of more convenient methods of using the characteristics of the hydraulic drive. The main role in the transformation of speeds and torques of the hydraulic drive is assigned to two of its properties: the graphical representation of these two properties on the operational characteristics of hydraulic turbo-transmissions has been called stiffness and opacity.
The total heating surface of a mine calorifier is calculated by the maximum heat release required from it Qtmax(kj/h), calculated by the absolute minimum of the outside air temperature for a given location from the expression...
It is known that at the vast majority of mines and mines located in areas with harsh climate, in winter time part of the atmospheric air supplied to underground workings for their ventilation is heated. To do this at the shafts and adits, where the ventilation jet comes, build, as a rule, steam caloriferous installations with a multi-row arrangement of metal plate calorifiers, the sequential movement of heated air in them provides the necessary air temperature difference...
In connection with the development of new equipment for high-performance hydraulic mines the problem of creation of autonomous mining and sinking machines is put on one of the first places in the near future. Such machines can be self-propelled high-pressure hydraulic monitors.
The problem of automatic maximization of self-propelled hydraulic monitors productivity at development of coal seams by hydraulic method has not been solved yet, though practice has long ago established that the dependence between the hydraulic monitor productivity q and the speed of its trunk movement v along the face front has an extreme character. As can be seen from Fig. 1, the top A, which characterizes the optimal operating mode, under the influence of changes in mining and geological conditions drifts...
В последние годы на ряде угольных шахт Кузнецкого, Печорского и Карагандинского бассейнов зимой практикуется подогрев всего воздуха, поступающего в шахту. На подавляющем числе рудников и шахт, расположенных в районах с суровым климатом как в СССР, так и за границей, преобладают системы вентиляции с калориферными установками, осуществляющими частичный подогрев. В таких системах свежий атмосферный воздух с наружной температурой tmpразделяется на два обособленных потока, один из которых подогревается в калориферах до ^под — 60—80° С и смешивается в калориферном канале или в устье ствола с другим, неподогретым потоком, образуя смесь воздуха с температурой tCM> 2° С. Принудительное движение воздуха через калориферы осуществляют в рассматриваемых системах особые, относительно небольшие вентиляторы, называемые калориферными в отличие от мощных главных вентиляторов, обеспечивающих проветривание шахты или рудника ...
The study of destruction of coals and rocks by water jet was carried out in four main directions: 1) the process of destruction of rocks and some artificial materials under the application of; impact and static loads and identification of factors determining the energy intensity of such destruction; 2) the structure and parameters of free high-pressure water jets; 3) the process and energy intensity of rock destruction by water jet; 4) mathematical interpretations of laboratory research data and production observations and development of the basics of engineering theory of rock destruction by water jet.
Experimental study of the dynamics of free water jets that meet a rigid barrier on their way is very important for the accumulation of experimental data contributing to the establishment of a number of regularities necessary for the creation of the theory of hydraulic stripping of coal from the massif at hydromechanization of coal-mining works.Of primary importance in such experiments is the identification of the jet impact force on the barrier depending on the water pressure in the jet-producing device, on the diameter of the nozzle outlet and the distance from the latter.
When designing mining and tunneling mining machines operating on the principle of hydraulic stripping, it is important to know the dependence of productivity and energy consumption of solid bodies destruction by water jet on the speed of movement of the jet axis relative to the bottom face, on the water pressure in front of the nozzle, as well as on other parameters (radius of rotation of the nozzle, distance from the nozzle to the body to be destroyed, etc.).
Reliability of the braking device is of particular importance in the transfer of lifting systems from manual control to automatic.All domestic lifting machines, having coiling apparatuses with a diameter of 4 m and above, are equipped with a fast-acting pneumatic braking device Novo-Kramatorskiy machine-building plant (NKMP).
In practice of development of coal and ore deposits and in non-metallic mines there is a necessity in construction of rope cargo bremsbergs with variable inclination angle. At modern coal mines bremsbergs at inclination angles up to 18° and at relatively significant productivity are equipped with belt conveyors. In mine workings, the angle of inclination of which exceeds 40°, the descent of minerals, as a rule, is carried out on fixed chutes (grates).
Heating the air supplied to the mine for ventilation of underground workings in winter ensures uninterrupted operation, improved occupational safety and health protection of workers, extension of the service life of reinforcement and fastening of mine shafts and reduction of expenses for their repair. The requirement for mandatory heating of ventilation air in the mines of the Ministry of Coal Industry of the USSR in winter was first included in the "Rules for the Technical Operation of Coal Mines" (abbreviated PTE) in 1941. § 840 of the PTE states: ""For shafts with an incoming stream, there must be heating (non-fire) devices that ensure maintaining the air temperature below the junction of the heater channel with the shaft of at least +2°." Before the issuance of the PTE, the need to heat the air supplied to mine workings was not mandatory. In 1948, the need for mandatory air heating was included in the Mintsvetmet PTE in a slightly different version. In modern mine heating units, it is common to heat only part of the ventilation air to a temperature of 60-100° C. The air heated to this temperature is directed by a special fan through the heating channel into the mine shaft, where the heated air is mixed with the main flow of cold air coming from the earth's surface through the mouth of the shaft.
The proposed work is devoted to the consideration of the conditions for introducing ventilation air into mine shafts, heated in winter by mine heating units. This refers to the suction system of mine ventilation, which is accompanied by the presence of a heating unit with its own fan and an underground heating channel at the air supply shaft. The main mine fan in such a ventilation system is located at the ventilation shaft. The work separately considers the conditions for introducing heated air into vertical and inclined mine shafts.
