Monika Hardygóra

Computerised Decision-Making Support System Based on Data Fusion for Machinery System’s Management and Maintenance

In the present fast-paced world of business in a highly competitive marketplace, the focus on increasing the efficiency of business processes seems to be a reasonable challenge. For this reason in order to optimize production costs, there is an increasing trend toward maximising the use of the operational capabilities of the equipment – technological line components – with the prevention of failure events and their consequences in the form of costly repairs or replacements. A condition-based maintenance (CBM) approach allows to globally monitor, maintain and control operation of the whole complex of equipment and/or processes. The CBM effectively supports decision-making process concerning their further use or determination of the optimum repair/replacement schedule. The presented decision support system is dedicated for an underground copper mine, where the network of belt conveyors is a critical part of the production process. Due to complexity of mechanical system, harsh mining environment and presence of many degradation factors, development of the effective CBM system seems to be justified. It requires the integration of data from different sources, adaptation of advanced data mining techniques, procedures or various diagnostic methods. Because of the multidimensional nature of diagnostic data and diversified technical configurations of the facilities, it was necessary to develop and implement multivariate analytical models based on artificial intelligence techniques. Consequently, it allows to achieve improvement of efficiency of transportation network and reduction of repairs costs and unplanned breakdowns. In this paper we will briefly refer to all these issues.

Some Remarks on Using Condition Monitoring for Spatially Distributed Mechanical System Belt Conveyor Network in Underground Mine – A Case Study

The paper deals with application of condition monitoring and information system to maintain of complex, spatially distributed machinery system, namely belt conveyor transportation network, which consists of hundreds of drive units located on mine territory. There is simple question: what managers/engineers should do to ensure safe and efficient work of transportation machines? It has appeared that number of objects, their spatial location, specific structure of mining company, harsh environment, diversity of machines etc make this problem really complicated. It is obvious that there is a need to use specialized equipment, software but first of all set of procedures of data acquisition, validation, processing, storage, visualization, decision making, reporting etc, so in other words maintenance management. All these stages, combined and implemented as maintenance management software called Diag Manager (CMMS class) is discussed here.

Novel Techniques of Diagnostic Data Processing for Belt Conveyor Maintenance

In the paper a new diagnostic approach for gearbox used in belt conveyors will be discussed. The purpose of the work is to provide novel view on diagnostic data processing in the context of detection of changes in condition for population of gearboxes used in belt conveyor network. The idea will be presented by examples: a data base of diagnostic features collected during last 3 years (real data from conveyors operating in mining company) will be used for illustration.

Diagnostic Features Modeling for Decision Boundaries Calculation for Maintenance of Gearboxes Used in Belt Conveyor System

Condition-Based maintenance (CBM) becomes more and more popular in industry. The idea is simple: measure raw data (vibrations, temperatures, etc.), extract features and make a right decisions regarding replacement of the whole machine or its component at appropriate time. Right decision might mean simple if-then-else rule or complex decision making scheme using multidimensional data. In any case mentioned rules require definition of appropriate thresholds for diagnostic parameters (i.e. decision boundaries). This is a key problem in CBM. The article presents the procedure for determining decision thresholds based on statistical modeling of diagnostic data. In the presented procedure first we fit the suitable distribution (Weibull) to data set for each gearbox. Next we calculate the fitting quality measure and select the distribution parameters for well fitted data. Finally, on the basis of the multidimensional analysis of those parameters we determine threshold values for the effective identification of the machines’ condition and their components. It might be interpreted as training process of diagnostic system. From this phase of the procedure we can obtain thresholds for warning and alarm statuses and they can be used for classification of rest of the data (that did not pass modeling phase). Proposed procedure has been applied to relatively large diagnostic data set that covers nearly 150 measurements acquired during several years in underground mine. The data describes gearboxes in different conditions—from nearly new or after repair to seriously damaged/worn just before failure.

Impact of Selected Parameters on the Fatigue Strength of Splices on Multiply Textile Conveyor Belts

Splices are the weakest points in the conveyor belt loop. The strength of these joints, and thus their design as well as the method and quality of splicing, determine the strength of the whole conveyor belt loop. A special zone in a splice exists, where the stresses in the adjacent plies or cables differ considerably from each other. This results in differences in the elongation of these elements and in additional shearing stresses in the rubber layer. The strength of the joints depends on several factors, among others on the parameters of the joined belt, on the connecting layer and the technology of joining, as well as on the materials used to make the joint. The strength of the joint constitutes a criterion for the selection of a belt suitable for the operating conditions, and therefore methods of testing such joints are of great importance. This paper presents the method of testing fatigue strength of splices made on multi-ply textile conveyor belts and the results of these studies.

Maintenance of Belt Conveyor Systems in Poland – An Overview

The tendency to increase efficiency and safety in mining industry leads to quick development of monitoring, diagnostic and management systems. It can cover different aspect of mining activities. In this paper recent achievement in Polish mining industry related to machinery systems will be discussed. Selected solutions deployed by research teams from Wroclaw University of Technology in both opencast and underground mining companies in Poland will be briefly presented and discussed. The purpose of this paper is to provide current state of the research and practices focused on maintenance of belt conveyors. In particular, among others, following projects will be overviewed :i) Online monitoring system for drive units developed for lignite mine, ii) Portable monitoring system for conveyor belt with steel cords developed for lignite mine, iii), Diag Manager – maintenance system for belt conveyor transport network, iv) Laboratory and in situ research on belt conveyor technology (belts, joints, idlers resistance to motion, energy efficiency, etc). The Authors will try to summarize challenges in this field and point out future work at the end of the paper

Conveyor Belt Condition Evaluation via Non-Destructive Testing Techniques

Belt conveyors seem to be the primary transportation technique for mining materials in many countries, especially it is the case in the mining industry in Poland. One of the key and challenging issue is maintenance policy for conveyor belt, probably the most critical part of a conveyor. The total length of conveyor belts in Polish mining industry exceeds 2,200 km. Taking into account safety, economic, reliability and other aspects, maintenance of these belts becomes a serious task. How to detect damages in a belt? How to relate detected damages and condition assessment? When a belt segment (splice, whole belt loop on a conveyor) should be replaced? When the actual belt tensile strength matches the operational requirements? To answer these questions the up-to-date results on Non-Destructive Testing techniques developed for opencast lignite mining are presented in the paper. These techniques are related to vision systems, magnetic systems and infrared thermography. Some of them are still being tested in laboratory conditions, while other are already in deployment phase though it seems to be useful to share recent experience and present the state-of-the-art. In the paper a brief idea of each applied method is explained and some both laboratory as well as industrial examples of investigation are discussed.

Evaluation of the Effectiveness of an Eco-Friendly Technology for Splicing Steel Cord Conveyor Belts

A new eco-friendly method of splicing steel cord conveyor belts without the use of noxious materials has been developed by the Mining Institute at Wrocław University of Technology in collaboration with the Bełchatów Lignite Mine – the two leaders in implementing state-of-the-art and environment friendly technologies in mining in Poland [1,2,3]. Polish lignite mines use belts with steel cords. Such belts are spliced through high temperature vulcanization, which is not safe for the environment and has an adverse impact on human health. Strength and durability are the two main properties of belt splices, having a bearing on the failure-free operation of the belt conveyors used for the haulage of stripped rock or muck in open pit mines [4,5,6]. This means that properly made steel cord belt splices should have the strength and durability parameters similar to the ones of the belt without splices. Many factors contribute to the quality of the splice, including the ones connected with the splicing technology, workmanship and with the fact that splices are made directly on conveyors in heavy mine conditions.