皮带运输机的节能控制系统设计

在矿用皮带运输机的应用中,部分煤矿缺乏运输作业的节能改进,借助传统的恒转速控制方式,存在轻载高速运行的电能过度耗费问题,需要做好节能化工作。为此,基于对皮带运输机及常用节能方式的了解,决定应用变频节能技术进行改造。其次,参考运输机运载量、带速和电能损耗三者关系,从控制系统设计目标、硬件结构设计和软件系统功能等方面出发,在合理应用煤量自动识别技术、模糊控制算法后,提出节能控制系统。最后,经过节能控制系统应用,能实现皮带运输机的节能控制。

Optimization of drilling and blasting operations in an open pit mine——the SOMAIR experience

Drilling and blasting play vital roles in opencast mining. These operations not only affect the cost of production directly but as well and significantly, the overall operational costs. This research was carried out to find a possible way of optimizing the drilling and blasting operations in an open pit mine of Somair (Société des Mines de l’Air), in the Niger Republic. In order to optimize the drilling operation, the time taken by two drilling machines to accomplish the same task was analyzed statistically. The result indicates that the Down the Hole Hammer Drilling Rig (DMNo406) is more efficient than the Drill Master (DM405). The relative unit consumption of two explosives (Explus and Nitram 9), when used under the same operating conditions, were also considered and the results indicate Explus to be more economical per unit consumption with a range of 0.15 g/t–0.183 g/t, when compared with Nitram 9 with a unit consumption range of 0.19 g/t-0.24 g/t in the study area.

Failure mechanism of pump chambers and their optimized design in deep mining at Qishan Coal Mine

Pump chambers, normally used as dominant structures in mining engineering to insure the safety and production of un-derground coal mines, become generally deformed under conditions of deep mining. Given the geology and engineering condition of Qishan Coal Mine in Xuzhou, the failure characteristics of pump chambers at the –1000 m level show that the main cause can be attributed to the spatial effect induced by intersectional chambers, where one pump is constructed per well. We developed an opti-mized design of the pump room, in which the pump wells in the traditional design are integrated into one compounding well. We suggest that the new design can limit the spatial effect of intersectional chambers during construction given our relevant numerical simulation. The new design is able to simplify the structure of the pump chamber and reduce the amount of excavation required. Based on a bolt-mesh-anchor with a rigid gap coupling supporting technology, the stability of pump chamber can be improved greatly.

Application of highwall mining system in weak geological condition

Almost all the coal is produced from open cut mines in Indonesia. As a consequence of open cut mine application, a great deal of coal is left out in the highwalls of the mined-out pits. Highwall mining systems can be used to recover this coal. The use of highwall mining systems has increasingly come into play in the US and Australia. However, it is not common in Indonesia. Moreover, Indonesia coal measure is categorized as weak geological condition. Some problems are likely to arise during the application of the highwall mining system for example instability of openings and highwalls due to the roof and pillar failures. Therefore, study of highwall mining system application in Indonesia is needed in order to increase the recovery rate of coal mining in Indonesia. This paper described the characteristics of the highwa!l mining system and discussed the appropriate highwall mining system application in weak geological condition, Indonesia. From the results of a series of laboratory tests and numerical analyses, it can be concluded that the stability of pillars and mine openings in auger mining systems is much higher than that in CHM and an auger mining system is suitable for such as very weak/poor strata conditions. Moreover, the application of backfilling system is very effective for improvement of the stability of pillar and openings.

Safety appraisement on building natural gas pipeline over coal mining subsidence area

The target of the text is to scientifically appraise dynamic development of surface deformation in subsidence area and its influence on groundwork stability of natural pipe and then adopt some technological measures to ensure safe circulation of natural pipeline. Analysed the influence on natural pipeline from coal mining subsidence in the way of pipeline grade variation, vertical curve variation, transverse deformation, horizontal pull and compression deformation and pipe stress variation etc., and described detailed surface subsidence product and its used time among initial phase, active phase and decline phase in the course of surface movement deformation time. In the context of considering surface subsidence that doesn＇t reach basic latter end and residual subsidence quantity, the text confirmed the calculation method of residual deformation in surface subsidence area, and gave the technological measures about building natural gas pipeline in subsidence area finally.

Application of reliability-centered maintenance for productivity improvement of open pit mining equipment:Case study of Sungun Copper Mine

Equipment plays an important role in open pit mining industry and its cost competence at efficient operation and maintenance techniques centered on reliability can lead to significant cost reduction.The application of optimal maintenance process was investigated for minimizing the equipment breakdowns and downtimes in Sungun Copper Mine.It results in the improved efficiency and productivity of the equipment and lowered expenses as well as the increased profit margin.The field operating data of 10 trucks are used to estimate the failure and maintenance profile for each component,and modeling and simulation are accomplished by using reliability block diagram method.Trend analysis was then conducted to select proper probabilistic model for maintenance profile.Then reliability of the system was evaluated and importance of each component was computed by weighted importance measure method.This analysis led to identify the items with critical impact on availability of overall equipment in order to prioritize improvement decisions.Later,the availability of trucks was evaluated using Monte Carlo simulation and it is revealed that the uptime of the trucks is around 11000 h at 12000 operation hours.Finally,uncertainty analysis was performed to account for the uncertainty sources in data and models.

GENERAL RELIABILITY THEORY STUDY ON SEMI-FLEXIBLE OUTPUT TYPE AND REPAIRABLE PRODUCTION SYSTEM

This paper puts forward the conceptions of semi-flexible units and semi-flexible system, and builds up the theory of semi-flexible output type and repairable production system general reliability analysis and general reliability design, which discusses the reliability problems of semi-flexible units and semi-flexible system from three aspects of time, task and capacity.

Market-oriented management method of coalmine accident hidden dangers

By analyzing the problems which exist currently in the accident hidden dangers management of the coal mine, this paper proposed a new kind of management method--＂simulating the market＂, in which an operation pattern of simulating the market to transact hidden troubles was constructed. This method introduces ＂Market Mechanism＂ into safe management, and adopts measurable value to describe the hidden dangers such as＂ human behavior, technique, environment, equipments etc.＂. It regards the hidden dangers as ＂the goods produced by labor＂ which are found out by the safety managers and the security inspectors, then sells as ＂commodity＂. By the process of disposing, counterchecking, re-selling, and redisposing. It forms a set of market-oriented closed-form management pattern of coalmine accident hidden dangers. This kind of management method changes the past traditional methods in which the wageworkers treat safety management passively, but to encourage and restrict them to participate in the check-up and improvement of the hidden dangers.

Design of forecast system of mining damage in mining areas and its realization

Exploited the forecast system of mining damages, which uses the theory of clean-production in coal-areas as guide. Its aims is developing and using coal resource reasonably and reducing the damage to the environment.

Roadway deformation during riding mining in soft rock

"Riding mining" is a form of mining where the working face is located above the roadway and advances parallel to it.Riding mining in deep soft rock creates a particular set of problems in the roadway that include high stresses,large deformations,and support difficulties.Herein we describe a study of the rock deformation mechanism of a roadway as observed during riding mining in deep soft rock.Theoretical analysis,numerical simulations,and on site monitoring were used to examine this problem.The stress in the rock and the visco-elastic behavior of the rock are considered.Real time data,recorded over a period of 240 days,were taken from a 750 transportation roadway.Stress distributions in the rock surrounding the roadway were studied by comparing simulations to observations from the mine.The rock stress shows dynamic behavior as the working face advances.The pressure increases and then drops after peaking as the face advances.Both elastic and plastic deformation of the surrounding rock occurs.Plastic deformation provides a mechanism by which stress in the rock relaxes due to material flow.A way to rehabilitate the roadway is suggested that will help ensure mine safety.

Reliability Analysis of Production System of Fully-Mechanized Face Based on Output Statistic

Production system of fully-mechanized face is a complicated system composed of human, machine and environment, meantime influenced by various random factors. Analyzing the reliability of system needs plentiful data by means of system faults statistic. Based on the viewpoint that shift output of fully-mechanized face is the result of various random factors’ synthetical influence, the process of how to analyze its reliability was deduced by using probability theory, symbolic statistics theory and systematic reliability theory combined with the concrete case study in this paper. And it has been proved that this method is feasible and valuable.