Scraper Conveyor Research Articles

Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams

Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams

A Cooperative Control Method for Fully Mechanized Mining Machines Based on Fuzzy Logic Theory and Neural Networks

In a fully mechanized mining face, the coordinated control of coal mining machines has a significant promoting effect to perfect the mining environment and improve the efficiency of coal production and has become a research focus all over the world. In this paper, a cooperative control method based on the integration of fuzzy logic theory and neural networks was proposed. The improved Elman neural network (ENN) through a threshold strategy was presented to predict the running parameters of coal mining machines. On the basis of coupling analysis of coal mining machines, the expert knowledge base of scraper conveyor was established based on fuzzy logic theory. Furthermore, the probabilistic neural network (PNN) was applied to evaluate the running status of scraper conveyor, and the cooperative control flow was designed and analyzed. Finally, a simulation example was provided and the comparison results illustrated that the proposed method was feasible and superior to the manual control.

Research on Influence Factors of Hydraulic Support Moving Velocity in Coal Mining Based on AMESim

In view of the high efficiency modernization coal demand, in this paper, the hydraulic support moving velocity influence factors were studied. Building simulation model of the thrust jack of hydraulic support with the simulation software AMESim, and run the simulation. Comparing the simulation results by setting different parameters value. It is concluded that the rated flow of pump station and hydraulic controlled check valve opening quantity will affect the speed of hydraulic support moving frame. This result provides reference for the optimal design of hydraulic support and improving the efficiency of coal mining. Key words: Moving velocity of hydraulic support; Rated flow; Hydraulic controlled check valve; AMESim 1 Tntroduction In the process of coal mining,the movement of hydraulic support needs in a timely manner with coal mining progresses, thrust jack plays a vital role for the movement of the hydraulic support. Therefore, it is very meaningful to research the influence factors of hydraulic support moving velocity With thrust control loop as the breakthrough point . 2 The working principle of the thrust control loop The movement of the hydraulic support and push the slide are achieved by thrust jack. Thrust jack is located in the middle part of the base of the hydraulic support, its end hinged with the base of the hydraulic support, the other end is connected with flexible scraper conveyor. When the hydraulic support moving, uninstall first, then the hydraulic controlled check valve make high pressure liquid into the piston rod cavity of thrust jack, the liquid in piston chamber flow back. At the same time, make thrust jack cylinder to move forward with the support of conveyor, thus, the whole hydraulic support is pulled to the coal wall, to complete the move. when pushing the slide, make high pressure liquid into the piston chamber , the liquid in piston rod cavity flow back, and, make the piston rod out with the support of hydraulic support. so,the conveyor is pushed to the coal wall,it is completed.

Determination of the Influence of an Anticorrosive Layer on the Strength of Link Mining Chains/Określenie Wpływu Warstwy Antykorozyjnej Na Wytrzymałość Łańcuchów Ogniwowych – Górniczych

Abstract Using link mining chains is related to the proper way of selecting the type of the chain. The operational parameters of the chain are associated with a risk to the employees who operate haulage systems using scraper conveyors. A complete analysis of operational parameters is possible to be made only after relevant tests are performed. The study presents laboratory test results as well as modeling studies which allowed to determine the influence of the anticorrosive protection of the chain’s surface on its operational parameters.

Vibration Signal Time-Domain Characteristic Extraction for Coal and Rock Recognition at the Fully Mechanized Top-Coal Caving Face

In order to avoid the over discharge and less discharge situations, improve the coal recovery rate and promote the working environment of workers at the fully mechanized top-coal caving face, experiments for the research of the coal and rock character recognition were carried on underground. Vibration signal at the hydraulic support tail beam and the rear scraper conveyor under different conditions were acquired at the fully mechanized top-coal caving face using the self-developed mine portable data recorder. The time-domain indexes of the vibration signal were analyzed. Results show that the variance, skewness index and kurtosis index changes most obviously under various stage of top coal caving and can be used as the time-domain characteristic indicator for the coal and rock character recognition in the fully mechanized working face.

INDUSTRIAL TESTS OF WASTE ROCK DIRECT BACKFILLING UNDERGROUND IN FULLY MECHANIZED COAL MINING FACE

For efficient, economical and environmentally disposing the waste rock underground, based on principles of waste direct backfilling in fully mechanized coal mining, this paper carries out a field test in 6304-1 working face of Jining No.3 Coal Mine. We first design a waste rock direct underground processing system, including screening-crushing system, transportation system, transfer system, stope backfilling system and coal mining system. Then optimize the waste backfilling and coal mining technology, update the waste backfilling process with start backfilling from backfill scraper conveyor s head to tail, gradually uplift tamping arm, gradually compact backfill materials, move backfill scraper conveyor forward when the tamping arm can t extend out and last fill roof gap by up material pushed by down material . At last, imply this system and check strata movement controlling effect by actual measuring the roof dynamic change law, which supported by the dense backfill body. The results show that the test working face can cut 0.6 million tons of raw coal one year, and direct backfill 0.74 million tons of waste rocks at the same time, and the maximum subsidence of immediate roof observed in situ is 340mm, the maximum caving speed is

Results of Experimental Research of Granular Materials Transportation by Tubular Scraper Conveyors

Abstract A full factor experiment (FFE33) of transporting bulk materials by a tubular scraper conveyor on a curved track was conducted. There were derived the regression equation dependencies of production and torque on pipe diameter, fill factor and linear velocity. The graphical dependence of production and torque on the above-mentioned factors was constructed, and regression coefficients for different materials were determined.

Development of a virtual maintenance system with virtual hand

Aiming to improve the flexibility of virtual maintenance operations, virtual hand was designed and applied in a virtual maintenance system. The structure of virtual hand was designed according to the real human hand and the frequently used gestures of virtual hand were elaborated. Moreover, the motion mapping from human hand to virtual hand was established and a framework which described the interaction mechanism of virtual maintenance system with virtual hand was proposed. Finally, a prototype system was developed and an example of scraper conveyor was provided. The application results indicated that virtual hand can simulate most of operations through real human hand and the flexibility of virtual maintenance operations was improved.

Memory cutting of adjacent coal seams based on a hidden Markov model

Height adjustment of a shearer cutting drum is one of the key processes involved when the shearer swings its cutting drum up and down on a fully mechanized mining face. Direct sensors are used to recognize the coal–rock interface for adjusting the shearer cutting drum; however, these sensors exhibit poor reliability and accuracy. A traditional memory cutting method is applied to avoid the deficiencies of direct sensors, but this method results in large residual errors and frequent adjustments of the shearer cutting drum. This paper proposes a hidden Markov model (HMM) memory cutting method for the shearer. The height of the shearer cutting drum is modeled by describing the collaborative automation of the shearer, scraper conveyor, and hydraulic supports. After analyzing the principle of traditional memory cutting for the shearer cutting drum, HMM memory cutting is developed by employing data correlation of adjacent coal seams. Moreover, the effectiveness of HMM memory cutting is compared with traditional memory cutting. Results indicate that HMM memory cutting effectively predicts the accurate height of the shearer cutting drum and reduces its adjustment frequency. The HMM memory cutting method tracks the coal–rock interface efficiently and enables the shearer to cut more coal seams and less rocks.

Computational Method on the Shearer Position

According to problems such as low accuracy, high error in the shearer body position, this paper proposes a new computational method combining with the information of shearer, scraper conveyor and hydraulic support in order to realize three machine positioning. Using the sensor information and static-dynamic fusion, this paper solves positioning problem of the three-dimensional in the process of the shearer movement, and derive the relevant formula. Through the laboratory simulation experiment and industrial field experiments of Xi'an Coal Mining Machinery Co., Ltd show that this system can effectively improve the precision and stability of the fuselage orientation, so as to provide security for realizing the memory of shearer cutting and remote control. DOI: http://dx.doi.org/10.11591/telkomnika.v11i9.3239

Asynchronous Permanent Magnet Coupler Hydraulic Coupler and Performance Analysis

This paper analyzes the three major problems exist in the long-term use of hydraulic coupler, a temperature rise effect is the hidden trouble of the normal operation of equipment; two is the site difficult to accurately control the charging liquid, starting power balance and shutdown can not control the scraper conveyer; three is the property of medium effects factors of hydraulic coupling torque; introduces the working principle of asynchronous magnetic coupling and unique five technical characteristics. The asynchronous magnetic coupling and hydraulic coupler has obvious technical advantages compared, can solve the long-standing hydraulic coupler in the production practice expect to solve urgently and has failed to solve the problem. Conclusion is the soft starter for asynchronous magnetic coupling for scraper conveyor is completely feasible.

Determination of the Friction Work of a Link Chain Interworking with a Sprocket Drum / Wyznaczenie Pracy Tarcia Łańcucha Ogniwowego We Współdziałaniu Z Bębnem Łańcuchowym

Abstract The significant abrasive wear of sprocket drum teeth and seats bottoms is observed during the exploitation of longwall scraper conveyors. For this reason, it is important to determine friction work in sliding conditions of the horizontal link on the tooth seat bottom and on the tooth flank and friction work in the joint of links in the context of such nodes’ abrasive wear. The different construction variants of sprocket drums can be compared by determining friction work in the sliding positions of the horizontal link on the drum. The determination of the losses of the power transmitted is a requisite condition in such situation for determining the efficiency values of chain meshing. The friction work of the friction couple of a sprocket drum - link chain consists of friction work of the horizontal link in the places where it contacts with the seat bottom Ag and the tooth flank Af and friction work in the joints of a horizontal link in the contact place with vertical links: in the front joint Ap and the rear joint At. The article presents dependencies enabling to determine the value of such work for specific geometric relations between the chain and the drum and different friction conditions. The curves of relative friction work and the values of total friction work on the seat bottom, on the tooth flank and in a front and rear joint of links are presented for examples of friction conditions.

Simulation of Filling and Solidification Processes of Rump Pan by Procast

The rump pan is the body and the load-carry device of Scraper conveyer. the material is ZG30MnSi. In order to improve the life of the casting.this paper simulated filling and solidification process of rump pan by Procast software,and predicted the position of shrinkage cavity and shrinkage porosity in castings.Then through improving gating system and add reasonable risers, optimal process parameters scheme is got.

Design of Electric-Hydraulic Control System for Hydraulic Powered Support in Fully Mechanized Mining Face

The constraint relation of three-key-equipment, including coal cutter, scraper conveyor and hydraulic support, applied in the safe, high-producing and high-efficient fully mechanized mining face, was introduced; the composition principle of electro-hydraulic control system, embedded in the hydraulic support, was discussed, and the design scheme of the composition and hardware system about the electro-hydraulic control unit was presented in this paper. And finally the scheme achieved the target that we can control and monitor the working condition in near real-time, on the ground, in the crossheading and in front of the mining face.

Rough Set Fuzzy Neural Network Fault Diagnosis for the over Current Detection of Coal Mining Scraper

In this paper the rough set fuzzy neural network is used to monitor the over current fault problem of the mining scraper conveyor motor driving system. The phase current signals are input into the neural network, and then the current signals are processed with fuzzy logic set theory for optimization. Because too many rules may lead to complex computation, the rough set theory is used to reduce the rules after the signal characteristics are extracted. The simulation results show that the precision and reliability of motor driving system of the mining scraper conveyor can be improved by this method.

The Green Design of Bracket of Scraper Part of Coal Mine Underground Horizontal Extension Transfer Machine

Recently, transporting coal in the coal mine is poor efficiency and too costly. Coal mine underground horizontal extension transfer machine is used to transport coal faster and better. To resolve the problem how to connect the scraper conveyer with tramcar in this system, the design of the bracket has been brought up. The bracket of scraper part is the main bearing of coal mine underground horizontal extension transfer machine, and all the scraper conveyer must be fixed in the bracket. In addition, the design of the bracket of scraper part not only considers the rationality in the structure, but also considers the effect of the environment. The system works in extreme circumstances, but the green design can resolve it. It can effectively combine the choice of material, the structure of the bracket, the methods of technology with exterior styling, reflecting the human, machine of harmony with the working environment.

Backfilling technology and strata behaviors in fully mechanized coal mining working face

Based on the principle of fully mechanized backfilling and coal mining technology and combined with the Xingtai Coal Mine conditions, we mainly optimized the coal mining equipment and adjusted the coal mining method in the Xingtai Coal Mine 7606 working face for implementation this technology. Firstly, we define the practical backfilling process as the “(from backfilling scraper conveyor’s) head to tail backfilling, step by step swinging up of the tamping arm, gradual compacting, moving formed backfilling scraper conveyor when the second tamping arm cannot pass and connecting the immediate roof by back material push front material movement”. Meanwhile, the stress changes of backfill body in coal mined out area was monitored by stress sensors, and the roof caving law was analyzed by monitoring the dynamic subsidence of −210 west roadway of this face. The site tests results show that using this new backfilling and coal mining integrated technology, the production capacity in the 7606 working face can reach to 283,000ton a year, and 282,000ton of solid materials (waste and fly ash) is backfilled, which meets the needs of high production and efficiency. The goaf was compactly backfilled with solid material and the strata behavior was quite desirable, with an actual maximum vertical stress of the backfill body of 5.5MPa. Backfill body control the movement of overburden within a certain range, and there is no collapses of major areas in the overlying strata upon backfilled gob. The maximum subsidence and speed were 231mm and 15.75mm/d respectively, which proved the practical significance of this integrated technology.

Development of Hydraulic Security Shearing Machine for the Annulus Chain Used in Coal Mine

In view of the situation of shearing the scraper chain frequently and adjusting the pitch chain of the scraper conveyer in the coal mine, the project design a kind of hydraulic security shearing machine for the annulus chain of scraper conveyer, to solve the problem for high strength and heavy gauge annulus underground coal mine to cut off.

Fully Mechanized Coal Mining Technology for Thin Coal Seam under Complicated Geological Conditions

In view of the present situations and existing problems of thin coal seam mining under complex geological conditions, low-profile mining equipment for fully mechanized coal mining was developed. This paper presents the study on the development of the equipment. The low-profile mining machinery includes the shearer, the scraper conveyer, the hydraulic powered supports and others. A highly efficient cutting system with a high-power mechanical drive was utilized to improve the rock breaking capacity. The ultrahigh-temperature laser cladding technology was applied in the cutting equipment for wear-resisting sparkless coal and rocks excavating, suitable for highly gassy mines. The lead-angle friction theory and the side-pushing principle of angled panel forward movement were applied in the development of the moldboard coal-loading equipment. This development successfully achieved a coal-loading rate of over 98% and ensured smooth movement of the scrapper. Automation was implemented with electro-hydraulic technology and shearer remote control technology in main coal mining operations such as the movement of hydraulic support and conveyor. The automation enabled fast mining operations following the rapid movement of the cutting machinery. Furthermore, advanced computer simulations and optimizations were conducted to achieve optimal structural designs of the hydraulic powered supports. With the above development of low-profile mining equipment, fully mechanized mining of thin coal seams under the complex geological conditions was achieved. The development equipment has great potential to be widely applied in coal mines with similar conditions.

Study on Topology Optimum Design of Baffle of Scraper Conveyer

At present the study on the application of the topology optimum design in scraper conveyor is still under development. In this paper the topology optimization based on the homogenization method is applied to the design of the baffle on the scraper conveyer, which can provide a valuable conceptual design scheme for the selection of the baffle pattern. In conjunction with the homogenization theory and Finite Element Method (FEA), the mathematical models for designing the baffle by the minimizing mean compliance are developed in this paper. By applying the topology optimum design to the baffle, the topology optimization based on the homogenization method is proved to be reliable and practical at the conceptual design stage of baffle.