scholarly journals Failure Rate Prediction of Belt Conveyor Systems using 2-parameter Weibull distribution

2021 ◽  
Vol 9 (10) ◽  
pp. 1035-1039
Author(s):  
Olutayo Opeyemi Ogunmilua
Keyword(s):  
Failure Rate ◽  
Scale Parameter ◽  
Mining Industry ◽  
Conveyor Belt ◽  
Time To Failure ◽  
Belt Conveyor ◽  
System 2 ◽  
Accuracy Of Results ◽  
Component Failures ◽  
Belt System

Abstract: The conveyor belt is one of the most operational critical equipment’s in the mining industry, they are mostly used in the transportation of crushed materials from the crushing station to where there’ll be further processed. Due to the increasing complexity of belt conveyor systems, managing their integrity has become even more difficult, as they are now used across various industries, environments and carry materials of different weight variations, leaving them susceptible to failures (1). This paper provides an industry specific knowledge on how Weibull analysis can be used to predict the failure rate of a conveyor belt system, using parameters such as the time to failure (TTF), installation and failure dates, as determinant parameters for the predictions. Several Weibull failure distributions and functions have been used to establish accuracy of results and to create comparisons on the different ways in which risk, unreliability and availability are quantified, using calculated values such as the Shape and scale parameter. The paper utilizes real world case studies in the area of mining, which sheds light on key component failures and their cut sets within the conveyor belt system (2) Keywords: TTF, TTR, Threshold parameter, Repair date, Shape parameter, B10, B15, B20, Scale parameter, ECA, CDF, PDF

scholarly journals Establishing failure patterns of a Belt Conveyor System configuration

2021 ◽  
Vol 9 (10) ◽  
pp. 1030-1034
Author(s):  
Olutayo Opeyemi Ogunmilua
Keyword(s):  
Fault Tree ◽  
Fault Tree Analysis ◽  
Mining Industry ◽  
Conveyor Belt ◽  
Belt Conveyor ◽  
Specific Knowledge ◽  
Conveyor System ◽  
Tree Analysis ◽  
Failure Patterns ◽  
System 2

Abstract: The conveyor belt is one of the most operational critical equipment’s in the mining industry, they are mostly used in the transportation of crushed materials from the crushing station to where there’ll be further processed. Due to the increasing complexity of belt conveyor systems, managing their integrity has become even more difficult, as they are now used across various industries, environments and carry materials of different weight variations, leaving them susceptible to failures (1). This paper provides an industry specific knowledge on belt conveyor systems, their respective components, and how they are configured using fault tree analysis to predict the different branches of event that can contribute to the failure of a belt conveyor system. The use of fault tree analysis sheds more light on how cascading failures can occur, where the failure of one component leads to the failure of the overall system. (2) Keywords: RCFA, FMEA Opex, FTA, Capex, Eca, Ttf, Ttr.

scholarly journals Analysis of Transient Belt Stretch for Horizontal and Inclined Belt Conveyor System

2019 ◽  
Vol 4 (5) ◽  
pp. 1169-1179 ◽  
Author(s):  
Sanjay G. Sakharwade ◽  
Shubharata Nagpal
Keyword(s):  
Conveyor Belt ◽  
Belt Conveyor ◽  
Conveyor System ◽  
Structure Damage ◽  
Starting Condition ◽  
Maximum Value ◽  
Sudden Rise ◽  
Static Calculation ◽  
Standard Value ◽  
Belt System

Belt is costliest part of belt conveyor system. Sudden rise in belt tension within transient starting condition, results in belt failure and structure damage. It is difficult to measure these stresses by static calculation method and hence their presence might go undetected. Belt elongation is an evident quantity for these stresses. Dynamic belt stretch is formulated in terms of displacement response of conjugative belt units with respect to time. This paper presents analysis of the event and propagation of dynamic belt stretch for straight horizontal and straight inclined belt conveyor system. Dynamic behavior of belt system is investigated for starting condition of fully stacked conveyor belt. Belt conveyor system is considered as series of vibrating mass and its unit is assumed to be a viscoelastic segment. Equation of motion of belt unit is developed by Lagrange’s approach. Observed transient parameters are more vibrant in inclined belt than the horizontal belt system. Maximum value of dynamic belt stretch for horizontal belt systems founds 1.13% of total belt length and for inclined belt conveyor system, it is 1.16% of belt length. Both values are within range of standard value specified for fabric belt system.

scholarly journals Time to failure assessment of products at service conditions from accelerated lifetime tests with stress-dependent spread in life

2007 ◽  
Vol 27 (2) ◽  
pp. 209-233 ◽  
Author(s):  
Enrique López Droguett ◽  
Ali Mosleh
Keyword(s):  
Comparative Analysis ◽  
Shape Parameter ◽  
Scale Parameter ◽  
Time To Failure ◽  
Failure Assessment ◽  
Accelerated Lifetime ◽  
Lifetime Testing ◽  
Service Conditions ◽  
Stress Dependent ◽  
Parameter Dependency

In accelerated lifetime testing (ALT) the assumption of stress-independent spread in life is commonly used and accepted because the resulting models are typically easier to use and data or past experience suggest that such a constrain is sometimes valid. However in many situations and with a variety of products the spread in life does depend on stress, i.e., the failure mechanism is not the same for all stress levels. In this paper the assessment of product time to failure at service conditions from ALT with stress-dependent spread is addressed by formulating a Bayesian framework where the time to failure follows a Weibull distribution, scale parameter dependency on stress is given by the Power Law, and two cases for the dependency between shape parameter and stress are discussed: linear relationship and, in order to allow a comparative analysis, stress-independent shape parameter. A previously published dataset is used to illustrate the procedure.

scholarly journals Segregation of the bulk cargo on a belt conveyor under the vibro-pulse impact

2021 ◽  
Vol 303 ◽  
pp. 01044
Author(s):  
Alexander Zakharov ◽  
Natalya Erofeeva
Keyword(s):  
Negative Impact ◽  
Conveyor Belt ◽  
Shock Pulse ◽  
Belt Conveyor ◽  
Lower Face ◽  
Rotation Direction ◽  
Impact Device ◽  
Characteristic Points ◽  
Linear Sections ◽  
Shock Pulses

The dynamics of interaction of the large lumps of the bulk cargo with a conveyor belt while passing through roller supports of the conveyor linear sections is often a cause of damage on the conveyor belt. In order to reduce the negative impact it is proposed to isolate the conveyor belt surface from the large lumps by filling small fractions of the bulk cargo by means of adding a shock device to the conveyor structure that causes increased segregation of the bulk cargo. A mathematical model of the segregation of the bulk cargo located on the conveyor belt and in zone of impact of the shock pulses has been developed. The model considers a change in the rotation direction of the large lump when applying shock pulses to the characteristic points of the lump lower face. Herewith it takes into consideration weakening of the shock pulse by a layer of the bulk cargo small fractions. The presented model has received experimental confirmation. Analytically and experimentally the height of filling of the bulk cargo small fractions under a large lump when passing the vibrating impact device located on the conveyor belt has been determined.

scholarly journals Non-reloading coal transportation in the eastern inclined shaft of “Raspadskaya” mine

2021 ◽  
Vol 303 ◽  
pp. 01027
Author(s):  
Vadim Yurchenko ◽  
Valeriy Nesterov
Keyword(s):  
Cross Section ◽  
Conveyor Belt ◽  
Belt Conveyor ◽  
Drive Power ◽  
Belt Drives ◽  
Belt Speed ◽  
Load Carrying ◽  
Drive Belt ◽  
Material Load ◽  
Belt Width

The planned increase in the mine output from 6.5 to 13.6 million tons per year has set the task of reconstructing a conveyor transport in the eastern inclined shaft of the Raspadskaya mine. The roadway length is 4100 m; the reduced inclination angle is +7°40´. An attempt was made to combine all the positive global practices in one project: the distribution of drive power along the length of a conveyor belt, minimizing the capital cost of implementation. Within the framework of this article, an approach to choosing the speed of a con-veyor belt is discussed, a comparative analysis of the two most com-mon types of intermediate “tripper-type” and “belt-to-belt” drives is given; calculation of a belt conveyor with intermediate “belt-to-belt” drives providing non-reloading conveying in the eastern inclined shaft. Pull force calculations showed that a conveyor belt with four interme-diate “belt-to-belt” drives can be implemented as follows: belt width – 1400 mm, belt speed – 4.0 m/s, mono-material load-carrying belt – PVG-4000, mono-material drive belt – PVG-1400, 2-pulley drive units when mounted on one side: head drive power – 2×1000 = 2000 kW, intermediate drive power – 2×1600 = 3200 kW. Thus, the use of a conveyor belt with four intermediate “belt-to-belt” drives in the in-clined shaft will give the following results: non-reloading transporta-tion over the entire length of the shaft, reducing the additional degra-dation of transported coal due to the exclusion of reloading points, minimizing costs through the use of less durable belts, minimizing costs of sinking an inclined shaft of a smaller cross-section.

scholarly journals Effect of Grid Instability on Power Generation System's Reliability

2020 ◽  
pp. 27-37
Author(s):  
Joseph Benedict Bassey ◽  
Isaac F. Odesola
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Failure Rate ◽  
System Reliability ◽  
Power Distribution ◽  
Power Plants ◽  
Time To Failure ◽  
Generation System ◽  
Reliability Indices ◽  
Mean Time

Aims: Reliability assessment of power generation system may be performed with the concept of system adequacy, security or both. Grid being a major component in the power distribution chain is seen to have some influence on the state of the generation system reliability because of the perturbation that may arise from it. In this study, the generation system reliability is evaluated using both the system adequacy and security concept. Study Design: To capture the system security problems attributed to grid disturbance, the generation system is structured into two component systems (1 - generation component and 2 - transmission component) with a series arrangement. Methodology: The reliability indices such as, mean time to failure, mean time to repair, failure rate and repair rate are assessed on component bases and with respect to the entire generation system. Results: The effect of failure rate of the transmission component on the entire generation system failure rate was evaluated as 66.25%, 55.55%, 33.33%, 55.00% and 35.72% in year 2013, 2014, 2017 2018 and 2019 respectively for FIPL Power Plant and 52.94%, 82.35%, 61.38% and 100% effect was evaluated in the year 2016, 2017, 2018 and 2019 respectively for GT5 of Omoku Power Plant. Conclusion: These results showed that there is a significant influence of grid disturbances on the reliability state of the two gas turbine power plants in Nigeria. Measures on possible reliability state improvement of the power generation systems were suggested to include training and retraining of technical personnel on the management of major equipment in the generation and transmission stations. 

Research on Spurious Trip of 1oo2 Safety Instruments of Petrochemical Installation with Repair Considered

2010 ◽  
Vol 118-120 ◽  
pp. 596-600
Author(s):  
Jian Xin Zhu ◽  
Xue Dong Chen ◽  
Shi Yi Bao
Keyword(s):  
Failure Rate ◽  
System Reliability ◽  
Repairable System ◽  
Time To Failure ◽  
Redundant System ◽  
Common Cause ◽  
System A ◽  
Definition Of ◽  
Mean Time ◽  
Complex Influence

An innovative nuisance trip calculation method based on Markov model was proposed in this paper which was used to evaluate the effect of repairment on system reliability. By analysis of the availabilities of classic 1 out of 2 (1oo2) repairable system, a new definition of spurious trip was put forwarded where online repair was considered. Compared with the benefits obtained by online repairment, the repair-caused-nuisance-trip was analyzed in this paper. Numerical calculation revealed that the online repair is helpful for anti-spurious trip in 1oo2 redundant system. Dangerous failures, if not repaired or cannot be online fixed, have complex influence on system reliability. The dangerous failure is sometimes benefit for anti-spurious performance if it is not repaired. But Mean Time To Failure Spurious (MTTFs) reduces with the increase of dangerous failure provided that dangerous failure rate is bigger than safe failure rate. Meanwhile, the finding that common cause can reduce the chance of nuisance trip was also proposed in this paper, though the influence is too small to be neglected.

scholarly journals Dynamic Behaviour of a Conveyor Belt Considering Non-Uniform Bulk Material Distribution for Speed Control

2020 ◽  
Vol 10 (13) ◽  
pp. 4436
Author(s):  
Fei Zeng ◽  
Cheng Yan ◽  
Qing Wu ◽  
Tao Wang
Keyword(s):  
Dynamic Model ◽  
High Precision ◽  
Material Flow ◽  
Laser Scanning ◽  
Bulk Material ◽  
Speed Control ◽  
Conveyor Belt ◽  
Distribution Model ◽  
Material Distribution ◽  
Belt Conveyor

For the conveyor belt, variable material flow influences the energy efficiency of the speed control technology significantly. The fluctuation of material flow on the conveyor belt will lead to the detrimental vibrations on both the belt and the conveyor while the conveyor works at certain speeds. In order to improve the model inaccuracy caused by the uniform bulk material flow assumption in the current conveyor belt model, the paper establishes a high-precision dynamic model that can consider speed control of a conveyor belt under non-uniform bulk material transportation. In this dynamic model, a non-uniform bulk material distribution model is firstly proposed based on laser scanning technology. Then, a high-precision longitudinal dynamic model is proposed to investigate the dynamic behavior of a belt conveyor. Considering the micro-units of actual load on a conveyor belt, it can well describe the transient state of the conveyor belt. These models can be used to determine the optimal speed for safety and energy conservation in operation. Experimental results are used to validate the proposed dynamic model for analyzing belt mechanical behavior under non-uniform bulk material distribution on the belt. The results show that the proposed models can be used for optimizing the operating procedures of belt conveyor systems.

scholarly journals Survival and failure trends of cerebrospinal fluid shunts with distal slit valves: comparative study and literature review

2020 ◽  
Vol 25 (3) ◽  
pp. 209-216
Author(s):  
Jeremy S. Wetzel ◽  
Alex D. Waldman ◽  
Pavlos Texakalidis ◽  
Bryan Buster ◽  
Sheila R. Eshraghi ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Failure Rate ◽  
Csf Shunt ◽  
Time To Failure ◽  
Survival Curves ◽  
Mean Time To Failure ◽  
Distal Catheter ◽  
Catheter Obstruction ◽  
Shunt Survival ◽  
Mean Time

OBJECTIVEThe malfunction rates of and trends in various cerebrospinal fluid (CSF) shunt designs have been widely studied, but one area that has received little attention is the comparison of the peritoneal distal slit valve (DSV) shunt to other conventional valve (CV) type shunts. The literature that does exist comes from older case series that provide only indirect comparisons, and the conclusions are mixed. Here, the authors provide a direct comparison of the overall survival and failure trends of DSV shunts to those of other valve type shunts.METHODSThree hundred seventy-two new CSF shunts were placed in pediatric patients at the authors’ institution between January 2011 and December 2015. Only ventriculoperitoneal (VP) shunts were eligible for study inclusion. Ventriculoatrial, lumboperitoneal, cystoperitoneal, subdural-peritoneal, and spinal shunts were all excluded. Rates and patterns of shunt malfunction were compared, and survival curves were generated. Patterns of failure were categorized as proximal failure, distal failure, simultaneous proximal and distal (proximal+distal) failure, removal for infection, externalization for abdominal pseudocyst, and addition of a ventricular catheter for loculated hydrocephalus.RESULTSA total of 232 VP shunts were included in the final analysis, 115 DSV shunts and 117 CV shunts. There was no difference in the overall failure rate or time to failure between the two groups, and the follow-up period was statistically similar between the groups. The DSV group had a failure rate of 54% and a mean time to failure of 17.8 months. The CV group had a failure rate of 50% (p = 0.50) and a mean time to failure of 18.5 months (p = 0.56). The overall shunt survival curves for these two groups were similar; however, the location of failure was significantly different between the two groups. Shunts with DSVs had proportionately more distal failures than the CV group (34% vs 14%, respectively, p = 0.009). DSV shunts were also found to have proximal+distal catheter occlusions more frequently than CV shunts (23% vs 5%, respectively, p = 0.005). CV shunts were found to have significantly more proximal failures than the DSV shunts (53% vs 27%, p = 0.028). However, the only failure type that carried a statistically significant adjusted hazard ratio in a multivariate analysis was proximal+distal catheter obstruction (CV vs DSV shunt: HR 0.21, 95% CI 0.05–0.81).CONCLUSIONSThere appears to be a difference in the location of catheter obstruction leading to the malfunction of shunts with DSVs compared to shunts with CVs; however, overall shunt survival is similar between the two. These failure types are also affected by other factors such etiology of hydrocephalus and endoscope use. The implications of these findings are unclear, and this topic warrants further investigation.

Session 9: Bulk Mail Conveying: Twin-Band Rising Conveyor

1969 ◽  
Vol 184 (8) ◽  
pp. 260-264
Author(s):  
A. J. Wilkinson
Keyword(s):  
Conveyor Belt ◽  
Confined Space ◽  
Belt Conveyor ◽  
Random Load ◽  
Twin Band ◽  
Load Conditions

It is often necessary to convey and elevate objects of widely varying characteristics in a confined space with random load conditions. The twin-band rising conveyor is essentially a steeply inclined belt conveyor which carries and controls articles on inclines of up to 60°. In order to control satisfactorily articles handled on such a conveyor, a continuous and weighted cover band, which is driven in synchronism with the conveyor belt, is employed. A horizontal toe band, which may be manually or automatically loaded, is used to aid efficient introduction to the articles between the carrying and weighted belts.

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