This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.
Since the majority of emergencies on belt conveyors of mining enterprises are associated with the conveyor framework, the article considers the failures of its elements - roller supports. The process of functioning of the framework is presented as a Markovian process of death and reproduction for a system of n parallel connected elements (roller supports) with intensity of failure and recovery λ r and μ r , respectively. The maximum permissible number of non-working roller supports, as well as the required number of roller supports replacement per shift to prevent an emergency on the conveyor, are determined. The value of the risk of conveyor framework failure K was also determined. Thus, for the given operating conditions, load flow characteristics and conveyor parameters, it is possible to calculate the maintenance intensity at which the risk of an emergency is minimal. This allows for efficient planning of belt inspections and repairs. To eliminate the risk of emergencies a patent-pending method for monitoring the technical condition of a belt conveyor framework by automatically monitoring the number of idle rollers on the framework has been developed. This prevents accidents caused by belt breakage and fire, as well as loss of traction of the conveyor drive.
Surface mining operations lead to an increase in the depth of open pits. As a result, there is a need to choose a conveyor transport, which allows transporting rock mass to a great height at high lifting angle. Conveyors with deep trough belts and tubular and steep incline belt conveyors are used to transport rock mass along curved and vertical routes. The use of conveyors adapted to the conditions of deep open pits allows to reduce the length of the route and to cut capital expenditures and energy costs for transporting rock mass. The main difference the existing types of steep incline conveyors is the way the cargo on the belt is kept from spontaneously moving downwards. In this work, the main types of steep incline conveyors, their advantages and disadvantages are considered. It is noted that in order to achieve maximum efficiency in transporting large pieces of rock mass in deep open pits, it is advisable to use double-circuit type "sandwich" belt conveyors, and partitions on the cargo belt. Steep incline conveyors and belts developed by Flexowell (USA), Savatech (Ukraine), Metso Outotec (Finland), ContiTech Transportbandsysteme GmbH (Germany), and steep incline conveyor with a double-circuit belt (Uzbekistan) are considered. Recommendations for choosing the type of steep incline conveyor are given. The main technical and technological parameters of tubular conveyors, which are currently in operation, are considered. It is noted that the maximum angle of inclination of tubular belt conveyors for transporting bulk cargoes depends on the coefficient of internal friction of the cargo, the coefficient of friction of the cargo on the belt and the rate of the belt filling. The ranges of change in the maximum angles of inclination of tubular conveyors are determined. Based on the analysis of the technical and technological parameters of the maximum angles of inclination of a tubular conveyor and a belt hold-down conveyor, it was found that the maximum angle of inclination of the hold-down conveyor is 5–10degrees higher than the maximum angle of inclination of the tubular conveyor. However, the cost and design complexity of the hold-down conveyor is higher than that of a tubular conveyor. It is recommended to use tubular conveyors on sections of the route with an inclination angle of up to 30 degrees. Keywords: open pit, steep incline conveyer, belt, angle of inclination, cargo.
The article deals with the issue of the loss of traction capacity of the drive of belt conveyors. The main reasons for the loss of traction capacity of the conveyor drive are determined, and the case of the loss of traction capacity of the drive due to th
Conveyor transport of mining enterprises is a constant source of accidents. With increasing depth of mines and quarries and with an increase of the load on the transport systems, the problems of ensuring the safety and health of people, environmental protection. The solution of these problems is associated with the development of the theory of reliability of technical systems and the assessment of technogenic risks. Currently, in connection with the tightening of environmental requirements, a promising area is the use of tubular belt conveyors that cause the least damage to the environment compared with other types of conveyor transport. Due to the more complex processes occurring when tubular conveyors operate, risk factors and their consequences differ significantly from risk factors for other types of conveyor transport. Based on the experience of operation and from the preliminary analysis of the processes occurring during the operation of tubular conveyors, for them a classification of risk factors is external and internal factors, as well as risk factors affecting a person. The risk factors from external influences include temperature, humidity, dustiness of the atmosphere, soil instability, weather conditions, physical properties of load, geometry of the route. Internal risk factors are errors in designing, calculating the constructive and regime parameters of the conveyor, violation of the rules of operation and safety. Risk factors affecting a person when working a tubular conveyor are classified as mechanical, thermal, electrical and chemical. In addition, risk factors for a tubular conveyor are classified according to individual nodes of drive, stand, and belt. The risks of the failure of supports rollers of the tubular conveyor are considered. It is given a failure tree, where possible rollers failures are listed in detail and the risks of the torsion of the tubular belt leading to the conveyor failures.
At present, due to the complexity of technical systems, industrial production is becoming a source of accidents, disasters, leading to large human and material losses, as well as to environmental pollution. In particular, this applies to conveyor systems for mining enterprises. The main causes of accidents and disasters in the conveyor transport of mining enterprises are the influence of the external environment, the reliability of equipment, as well as the level of operation. The experience of conveyor transport operating at mining enterprises has shown that a large number of accidents on conveyor belts is associated with failures of the frame. This is due to the fact that when the belt with a load moves along the conveyor frame, dynamic loads arise on the roller bearings leading to the failure of the pillow-blocks. At the same time, as the analysis of the data on operation of the belt conveyors shows, accidents that occur because of the rollers failure often lead to large material losses. These material losses are associated with the destruction of the rollers of the roller supports, as well as with the rupture of the conveyor belt. In addition, the elimination of accidents at the line of belt conveyors often lead to long downtime of the entire conveyor transport and, as a result, to a loss of its productivity. In this paper, on the basis of the theory of random Markov processes of death and reproduction, the risk rate in case of failure of the belt conveyor frame is determined by the factor of the rollers failure of the roller supports. The risk rate was determined as a mathematical expectation of the product of the probability of failures of rollers by the value of material losses caused by downtime of the conveyor and repair of roller supports. As a result, the dependence of the risk rate of failure of the belt conveyor frame on the conveyor productivity, the intensity of failures and recovery of the rollers of the roller supports, as well as on the average resource of the rollers, was obtained. It is established that with an increase in the conveyor productivity, the risk of failure of the belt conveyor becomes linear, and with a decrease in the recovery rate of the roller support, the risk increases according to the hyperbolic law. At the same time, with an increase in the failure rate of rollers, the rate of risk increases. In addition, with an increase in the resource of the rollers of the belt conveyor rollers bearings, the rate of the risk of failures of the frame decreases. It is established that the maximum rate of risk has the frame of a belt conveyor with rigid roller supports, and the minimum – the frame of a belt conveyor with shock-absorbed roller supports
Разработана математическая модель функционирования аккумулирующего бункера, работающего в системе конвейерного транспорта в режиме поддержания в нем объема груза в заданных пределах. При этом предполагалось, что интервалы времени простоев и работы надбункерной и подбункерной конвейерных линий распределяются по экспоненциальным законам. Определен максимальный объем аккумулирующего бункера, при котором пропускная способность системы «конвейер-бункер-конвейер» практически не увеличивается с увеличением объема бункера.
A mathematical model of the functioning of an accumulating bunker operating in the simplest transport system “conveyor-bunker-conveyor” has been developed. It was assumed thus, that time domains of outages and work of the above- and under-bunker conveyer lines are distributed on exponential laws. Based on the theory of two-phase Markov processes, a system of Kolmogorov equations is obtained with respect to the probabilities of finding the “conveyor-bunker-conveyor” system in various states. As a result of solving this system of equations, the dependence of the average carrying capacity of the system “conveyor-bunker-conveyor” on the volume of the bunker and the average cargo flow entering and unloading from the bunker is obtained. Based on the obtained dependence, the maximum volume of the accumulating bunker was determined at which the carrying capacity of the system “conveyor-bunker-conveyor” practically does not increase with increasing hopper volume.
В работе проведена классификация факторов риска ленточных конвейеров, работающих на открытых горных предприятиях и в угольных шахтах с точки зрения наносимого ущерба: технического, экономического, экологического и социального. Проведен предварительный анализ риска ленточных конвейеров, включая модификацию опасностей, т.е. выявление опасностей и предварительная оценка характеристик опасностей. В результате выявлены основные факторы риска ленточных конвейеров и получено дерево отказов ленточных конвейеров, работающих на горных предприятиях.Анализ риска всех типов ленточных конвейеров (общего назначения, глубокожелобчатых, с прижимной лентой и вертикальных) показал, что наиболее опасным воздействием на окружающую среду являются конвейеры общего назначения и вертикальные. При этом для крутонаклонных конвейеров с глубокожелобчатой лентой, а также вертикальных конвейеров существенным фактором опасности является неустойчивость крупных кусков груза на ленте конвейера.
Citations (3)
... It is impossible for conventional belt conveyors to move materials at angles when the lifting component exceeds the friction forces holding on the belt. In place of conventional belt conveyors, belt tubular conveyors are proposed [1][2][3][4][5]. Such conveyors can move materials not only at high angles but also be used for the spatial configuration of the track with bends in the horizontal and vertical planes at the same time. ...
... This leads to a non-uniform distribution of the material along the transport route (DIN _________ 22101:2002(DIN _________ 22101: -08, 2002. At the same time, specific energy consumption for rock transportation can significantly increase due to a decrease in the loading factor of the conveyor with material (Semenchenko et al. 2016;Kiriia et al. 2019). The low linear density of some conveyors cannot be compensated by an increase in linear density on other sides due to the maximum ultimate specific load limitations on the belt and the power of the electrical drives. ...
... Works [21][22][23] consider modeling the interaction of a tubular conveyor belt with roller supports. It is investigated how roller supports affect the holding capacity of the material by the belt. ...