Pub Date : 2020-04-02DOI: 10.1080/25726668.2020.1773124
R. Seedsman
ABSTRACT The height of collapse above a longwall extraction panel is simulated assuming a transversely isotropic continuum and an isotropic strength criterion. The transversely isotropic assumption allows consideration of the role of overburden conditions, specifically the spacing of bedding discontinuities. The shape and height of the collapse zone are like those produced in physical models and are consistent with subsidence measurements. The interaction between the disruption and break-through to the surface is examined using voussoir beam analysis. Break-through to the surface, which implies a fracture connection to the extraction level, may be associated with surface subsidence in excess of about 300 mm or a compressive strain in excess of about 4 mm/m.
{"title":"Prediction of the height of caving and fracturing above an isolated longwall extraction panel","authors":"R. Seedsman","doi":"10.1080/25726668.2020.1773124","DOIUrl":"https://doi.org/10.1080/25726668.2020.1773124","url":null,"abstract":"ABSTRACT The height of collapse above a longwall extraction panel is simulated assuming a transversely isotropic continuum and an isotropic strength criterion. The transversely isotropic assumption allows consideration of the role of overburden conditions, specifically the spacing of bedding discontinuities. The shape and height of the collapse zone are like those produced in physical models and are consistent with subsidence measurements. The interaction between the disruption and break-through to the surface is examined using voussoir beam analysis. Break-through to the surface, which implies a fracture connection to the extraction level, may be associated with surface subsidence in excess of about 300 mm or a compressive strain in excess of about 4 mm/m.","PeriodicalId":44166,"journal":{"name":"Mining Technology-Transactions of the Institutions of Mining and Metallurgy","volume":"53 1","pages":"103 - 95"},"PeriodicalIF":1.1,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75690012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-02DOI: 10.1080/25726668.2020.1749431
A. Maremi, E. Ben-Awuah, Y. Pourrahimian
ABSTRACT In oil sands mining, bitumen and fines contents are used to predict ore processability. However, experimental results show that certain solid fractions known as Organic Rich Solids (ORS) negatively affect the overall bitumen recovery. A conceptual mine planning framework based on a goal programming model for oil sands production scheduling and waste management is presented. Bitumen recovery is additionally adjusted based on the ORS content. The model features automated production targeting (APT) and limited duration stockpiling constraints that optimize the annual production capacities. The model is implemented with two scenarios. Scenario 1 uses processing recovery calculated based on Alberta Energy Regulatory requirements while Scenario 2 uses processing recovery additionally adjusted based on ORS content. Results for Scenario 1 show a 3.46% overestimation of net present value compared to Scenario 2. The APT constraints provide planners a robust and efficient technique for determining annual production tonnages with minimum periodic variations.
{"title":"An automated production targeting goal programming framework for oil sands mine planning considering organic rich solids","authors":"A. Maremi, E. Ben-Awuah, Y. Pourrahimian","doi":"10.1080/25726668.2020.1749431","DOIUrl":"https://doi.org/10.1080/25726668.2020.1749431","url":null,"abstract":"ABSTRACT In oil sands mining, bitumen and fines contents are used to predict ore processability. However, experimental results show that certain solid fractions known as Organic Rich Solids (ORS) negatively affect the overall bitumen recovery. A conceptual mine planning framework based on a goal programming model for oil sands production scheduling and waste management is presented. Bitumen recovery is additionally adjusted based on the ORS content. The model features automated production targeting (APT) and limited duration stockpiling constraints that optimize the annual production capacities. The model is implemented with two scenarios. Scenario 1 uses processing recovery calculated based on Alberta Energy Regulatory requirements while Scenario 2 uses processing recovery additionally adjusted based on ORS content. Results for Scenario 1 show a 3.46% overestimation of net present value compared to Scenario 2. The APT constraints provide planners a robust and efficient technique for determining annual production tonnages with minimum periodic variations.","PeriodicalId":44166,"journal":{"name":"Mining Technology-Transactions of the Institutions of Mining and Metallurgy","volume":"112 1","pages":"53 - 67"},"PeriodicalIF":1.1,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77578151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-02DOI: 10.1080/25726668.2020.1766302
R. Hansen
ABSTRACT Fires in underground mines may cause dangerous phenomena to mining personnel. One of these phenomena is the throttle effect, reducing the mass flow. This paper investigates the nature of the throttle effect. Data was provided from fire experiments in a model-scale mine drift. With an increasing heat release rate the reduction in the mass flow will increase. An increasing ventilation velocity may initially cause a reduction of the mass flow. With a further increase of the flow velocity the mitigating effect of the forced flow will increase. A dimensional analysis resulted in an equation where the mass flow reduction could be reasonably well described. It was found that the flow velocity had a weak effect on the mass flow reduction. Nevertheless, the flow velocity influence the initiation of the reduced mass flow. A full-scale flow velocity of 3.5 m/s was found to prevent the throttle effect for typical fires underground.
{"title":"Mass flow during fire experiments in a model-scale mine drift with longitudinal ventilation","authors":"R. Hansen","doi":"10.1080/25726668.2020.1766302","DOIUrl":"https://doi.org/10.1080/25726668.2020.1766302","url":null,"abstract":"ABSTRACT Fires in underground mines may cause dangerous phenomena to mining personnel. One of these phenomena is the throttle effect, reducing the mass flow. This paper investigates the nature of the throttle effect. Data was provided from fire experiments in a model-scale mine drift. With an increasing heat release rate the reduction in the mass flow will increase. An increasing ventilation velocity may initially cause a reduction of the mass flow. With a further increase of the flow velocity the mitigating effect of the forced flow will increase. A dimensional analysis resulted in an equation where the mass flow reduction could be reasonably well described. It was found that the flow velocity had a weak effect on the mass flow reduction. Nevertheless, the flow velocity influence the initiation of the reduced mass flow. A full-scale flow velocity of 3.5 m/s was found to prevent the throttle effect for typical fires underground.","PeriodicalId":44166,"journal":{"name":"Mining Technology-Transactions of the Institutions of Mining and Metallurgy","volume":"49 1","pages":"68 - 81"},"PeriodicalIF":1.1,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86771806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-02DOI: 10.1080/25726668.2020.1721996
Y. Madenova, Fidelis T. Suorineni
ABSTRACT The Stability Graph has become an industry standard for open stope design. To date, there are two schools of thought on the use of the Original and Modified Stability Graph number factors. This paper is aimed at answering the question: Is there a difference between the Original and the modified stability number factors? To answer this question, a critical examination of the Extended Mathews and Modified Stability Graph databases was conducted to create a combined database of 316 datapoints. One version of the database was based on the original number factors, while a second was based on the modified factors. Logistic regression methods were applied to redefine the stope stability state boundaries. We concluded that differences between the stope stability states transition zones in the Stability Graphs are due to the differences in size of the databases rather than differences in the Original and Modified Stability Graph number factors.
{"title":"On the question of original versus modified stability graph factors – a critical evaluation","authors":"Y. Madenova, Fidelis T. Suorineni","doi":"10.1080/25726668.2020.1721996","DOIUrl":"https://doi.org/10.1080/25726668.2020.1721996","url":null,"abstract":"ABSTRACT The Stability Graph has become an industry standard for open stope design. To date, there are two schools of thought on the use of the Original and Modified Stability Graph number factors. This paper is aimed at answering the question: Is there a difference between the Original and the modified stability number factors? To answer this question, a critical examination of the Extended Mathews and Modified Stability Graph databases was conducted to create a combined database of 316 datapoints. One version of the database was based on the original number factors, while a second was based on the modified factors. Logistic regression methods were applied to redefine the stope stability state boundaries. We concluded that differences between the stope stability states transition zones in the Stability Graphs are due to the differences in size of the databases rather than differences in the Original and Modified Stability Graph number factors.","PeriodicalId":44166,"journal":{"name":"Mining Technology-Transactions of the Institutions of Mining and Metallurgy","volume":"1 1","pages":"40 - 52"},"PeriodicalIF":1.1,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76208693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-02DOI: 10.1080/25726668.2020.1720371
A. Nieto, Rich S. Schatz, Cihan Dogruoz
ABSTRACT Load Haul Dump (LHD) equipment, haulers, and locomotives are essential to both hard and soft rock mining. Key performance indicators were calculated for both diesel and electric LHDs using the data provided by a multinational mining company operating metal mines. Battery-powered vehicles, having both the advantage of low maintenance and no tether to haul, showed an improvement in uptime. The electric fleet was, on average, operational 11 h longer than diesel vehicles before they are pulled off for maintenance. The results from comparing diesel and electric equipment show that the best equipment would be a fusion of the reliability of electric vehicles and the mobility of diesel equipment, both being attributes of battery powered equipment. Battery-powered vehicles are constantly improving and will only increase their prowess over diesel equipment.
{"title":"Performance analysis of electric and diesel equipment for battery replacement of tethered LHD vehicles in underground mining","authors":"A. Nieto, Rich S. Schatz, Cihan Dogruoz","doi":"10.1080/25726668.2020.1720371","DOIUrl":"https://doi.org/10.1080/25726668.2020.1720371","url":null,"abstract":"ABSTRACT Load Haul Dump (LHD) equipment, haulers, and locomotives are essential to both hard and soft rock mining. Key performance indicators were calculated for both diesel and electric LHDs using the data provided by a multinational mining company operating metal mines. Battery-powered vehicles, having both the advantage of low maintenance and no tether to haul, showed an improvement in uptime. The electric fleet was, on average, operational 11 h longer than diesel vehicles before they are pulled off for maintenance. The results from comparing diesel and electric equipment show that the best equipment would be a fusion of the reliability of electric vehicles and the mobility of diesel equipment, both being attributes of battery powered equipment. Battery-powered vehicles are constantly improving and will only increase their prowess over diesel equipment.","PeriodicalId":44166,"journal":{"name":"Mining Technology-Transactions of the Institutions of Mining and Metallurgy","volume":"504 1","pages":"22 - 29"},"PeriodicalIF":1.1,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87010473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-02DOI: 10.1080/25726668.2019.1651581
Leandro de Vilhena Costa, José Margarida da Silva
ABSTRACT Electricity is one of the biggest expenses associated with underground mining and ventilation often accounts for 50% of the total electricity use. Ventilation on demand is not widely used in Brazil, but the Ipueira, Cuiaba, and Corrego do Sitio I mines reported savings of 26%, 30%, and 21%, respectively, following its application. Frequency inverters are used to control the rotation of the main fans during shift changes. The Cuiaba mine has a control room and fans are monitored online using wireless scattered sensors. Data from field studies were compared to other foreign mines. The results showed that the application of this technique, even in an experimental way, can reduce electricity consumption significantly. Despite the energy savings that can be achieved by providing air only when/where it is needed, the costs of automation, software, and infrastructure mean that it is not practical to apply this technique at a more advanced level.
电力是与地下开采相关的最大费用之一，通风通常占总用电量的50%。按需通风在巴西并没有得到广泛应用，但Ipueira、Cuiaba和Corrego do Sitio I矿山在采用该系统后分别节省了26%、30%和21%的成本。变频器用于在换挡时控制主风机的旋转。库亚巴煤矿有一个控制室，风机使用无线分散传感器进行在线监控。实地研究的数据与其他外国矿山进行了比较。结果表明，即使以实验方式应用该技术，也可以显着降低电力消耗。尽管只在需要的时候/地方提供空气可以节省能源，但自动化、软件和基础设施的成本意味着在更高级的水平上应用这种技术是不切实际的。
{"title":"Cost-saving electrical energy consumption in underground ventilation by the use of ventilation on demand","authors":"Leandro de Vilhena Costa, José Margarida da Silva","doi":"10.1080/25726668.2019.1651581","DOIUrl":"https://doi.org/10.1080/25726668.2019.1651581","url":null,"abstract":"ABSTRACT Electricity is one of the biggest expenses associated with underground mining and ventilation often accounts for 50% of the total electricity use. Ventilation on demand is not widely used in Brazil, but the Ipueira, Cuiaba, and Corrego do Sitio I mines reported savings of 26%, 30%, and 21%, respectively, following its application. Frequency inverters are used to control the rotation of the main fans during shift changes. The Cuiaba mine has a control room and fans are monitored online using wireless scattered sensors. Data from field studies were compared to other foreign mines. The results showed that the application of this technique, even in an experimental way, can reduce electricity consumption significantly. Despite the energy savings that can be achieved by providing air only when/where it is needed, the costs of automation, software, and infrastructure mean that it is not practical to apply this technique at a more advanced level.","PeriodicalId":44166,"journal":{"name":"Mining Technology-Transactions of the Institutions of Mining and Metallurgy","volume":"54 1","pages":"1 - 8"},"PeriodicalIF":1.1,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79674648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-02DOI: 10.1080/25726668.2020.1721995
A. Adoko, J. Vallejos, R. Trueman
ABSTRACT Stress relaxation plays an important role in the design of underground stopes. The aim of this paper is to assess the stope stability in connection with the stress relaxation using a classification approach. Three types of stress relaxation were clearly defined, namely partial relaxation, tangential relaxation and full relaxation. A neural network classifier was implemented to assess the stability of the stopes on the basis of case histories of stope performances. The results of the classification were compared to existing empirical methods of quantifying the stress relaxation. Overall, the present study shows higher classification accuracies, especially when the stress relaxation was considered. The results suggested that the relaxation type can be a good predictor of stability. Relaxed stope (full and tangential stress relaxation) cases are the most critical in the sense that lower accuracies were obtained and the probability of correct classification is rather erratic.
{"title":"Stability assessment of underground mine stopes subjected to stress relaxation","authors":"A. Adoko, J. Vallejos, R. Trueman","doi":"10.1080/25726668.2020.1721995","DOIUrl":"https://doi.org/10.1080/25726668.2020.1721995","url":null,"abstract":"ABSTRACT Stress relaxation plays an important role in the design of underground stopes. The aim of this paper is to assess the stope stability in connection with the stress relaxation using a classification approach. Three types of stress relaxation were clearly defined, namely partial relaxation, tangential relaxation and full relaxation. A neural network classifier was implemented to assess the stability of the stopes on the basis of case histories of stope performances. The results of the classification were compared to existing empirical methods of quantifying the stress relaxation. Overall, the present study shows higher classification accuracies, especially when the stress relaxation was considered. The results suggested that the relaxation type can be a good predictor of stability. Relaxed stope (full and tangential stress relaxation) cases are the most critical in the sense that lower accuracies were obtained and the probability of correct classification is rather erratic.","PeriodicalId":44166,"journal":{"name":"Mining Technology-Transactions of the Institutions of Mining and Metallurgy","volume":"100 ","pages":"30 - 39"},"PeriodicalIF":1.1,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25726668.2020.1721995","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72495279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-02DOI: 10.1080/25726668.2019.1704546
F. Nadaraju, A. Maddocks, J. Zanganeh, B. Moghtaderi
ABSTRACT Ventilation air methane is low concentration methane (below 1 vol. %) emitted from an underground coal mine. High ventilation air volumes circulated through the mine, ensure that the methane remains at a safe concentration. In 2016, the Australian Government reported fugitive emissions of methane from underground coal mines at approximately 19.0 million tonnes (CO2-equivalent) which was about 4.0% of Australia's national greenhouse gas emissions. Therefore, an optimised process of heat recovery from a fluidised-bed VAM abatement reactor, to produce power and cooling was studied. For a ventilation flow rate of 20 m3/s, the minimum methane concentration for a direct gas turbine was 0.45 vol. % at a reactor temperature of 630°C and compressor pressure of 1.5 bar. An indirect gas turbine process operated with a minimum methane concentration was 0.4 vol. % at a reactor temperature of 630°C, compressor pressure of 4.0 bar and turbine flow rate of 2.2 kg/s.
{"title":"Ventilation air methane: a simulation of an optimised process of abatement with power and cooling","authors":"F. Nadaraju, A. Maddocks, J. Zanganeh, B. Moghtaderi","doi":"10.1080/25726668.2019.1704546","DOIUrl":"https://doi.org/10.1080/25726668.2019.1704546","url":null,"abstract":"ABSTRACT Ventilation air methane is low concentration methane (below 1 vol. %) emitted from an underground coal mine. High ventilation air volumes circulated through the mine, ensure that the methane remains at a safe concentration. In 2016, the Australian Government reported fugitive emissions of methane from underground coal mines at approximately 19.0 million tonnes (CO2-equivalent) which was about 4.0% of Australia's national greenhouse gas emissions. Therefore, an optimised process of heat recovery from a fluidised-bed VAM abatement reactor, to produce power and cooling was studied. For a ventilation flow rate of 20 m3/s, the minimum methane concentration for a direct gas turbine was 0.45 vol. % at a reactor temperature of 630°C and compressor pressure of 1.5 bar. An indirect gas turbine process operated with a minimum methane concentration was 0.4 vol. % at a reactor temperature of 630°C, compressor pressure of 4.0 bar and turbine flow rate of 2.2 kg/s.","PeriodicalId":44166,"journal":{"name":"Mining Technology-Transactions of the Institutions of Mining and Metallurgy","volume":"187 1","pages":"21 - 9"},"PeriodicalIF":1.1,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79378600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-28DOI: 10.1080/25726668.2019.1645519
P. Stothard, A. Squelch, R. Stone, E. V. van Wyk
ABSTRACT Twenty-first-century mining is a complex pursuit. Stakeholders must manage many interconnected processes and data sets to ensure an operation is sustainable. Mixed Reality (MR) simulation may present an opportunity to improve knowledge and understanding of mine operations via a digital twin. Current and future personnel can model and make predictions using past, current and future data sets. However, MR is still an uncommon tool in the mining industry. This paper asks why that is the case, what some common barriers may be to MR adoption, and presents a possible collaborative solution to make MR sustainable as the technology gains hold and becomes commonplace in mine operations and elsewhere.
{"title":"Towards sustainable mixed reality simulation for the mining industry","authors":"P. Stothard, A. Squelch, R. Stone, E. V. van Wyk","doi":"10.1080/25726668.2019.1645519","DOIUrl":"https://doi.org/10.1080/25726668.2019.1645519","url":null,"abstract":"ABSTRACT Twenty-first-century mining is a complex pursuit. Stakeholders must manage many interconnected processes and data sets to ensure an operation is sustainable. Mixed Reality (MR) simulation may present an opportunity to improve knowledge and understanding of mine operations via a digital twin. Current and future personnel can model and make predictions using past, current and future data sets. However, MR is still an uncommon tool in the mining industry. This paper asks why that is the case, what some common barriers may be to MR adoption, and presents a possible collaborative solution to make MR sustainable as the technology gains hold and becomes commonplace in mine operations and elsewhere.","PeriodicalId":44166,"journal":{"name":"Mining Technology-Transactions of the Institutions of Mining and Metallurgy","volume":"49 1","pages":"246 - 254"},"PeriodicalIF":1.1,"publicationDate":"2019-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89472605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT A significant problem with operating a coal mine fan is finding ways to save energy while still maintaining the required air supply to working faces. The authors developed and tested the performance of a K45-4-№9/18.5 kW axial mine fan adjusted by a variable frequency driver set to different fractions of a typical national electric grid frequency of 50 Hz. Its volumetric flow-rate and static pressure (Q-H) data were fitted with fifth-order polynomial equations using least-squares regression. The extremes of the Q-H curves descend with decreasing frequency and differ significantly from the predictions of classic affinity laws (CAL) in fluid dynamics. The air-flow power predicted by CAL theory deviates from the baseline of the fifth-order polynomial extremes by a maximum of 48%. Interestingly, the deviation between theoretical and experimental values increases with decreasing power frequency. These results are evidence of the theoretical overestimation of energy efficiency of an AMF adjusted by a VFD.
{"title":"Energy efficiency overestimated by classic affinity laws: relation between volumetric flow rate and static pressure of an axial mine fan adjusted by a variable frequency driver","authors":"Feng Tian, Haiqiao Wang, Shi-qiang Chen, Zhulong Zhu","doi":"10.1080/25726668.2019.1631623","DOIUrl":"https://doi.org/10.1080/25726668.2019.1631623","url":null,"abstract":"ABSTRACT A significant problem with operating a coal mine fan is finding ways to save energy while still maintaining the required air supply to working faces. The authors developed and tested the performance of a K45-4-№9/18.5 kW axial mine fan adjusted by a variable frequency driver set to different fractions of a typical national electric grid frequency of 50 Hz. Its volumetric flow-rate and static pressure (Q-H) data were fitted with fifth-order polynomial equations using least-squares regression. The extremes of the Q-H curves descend with decreasing frequency and differ significantly from the predictions of classic affinity laws (CAL) in fluid dynamics. The air-flow power predicted by CAL theory deviates from the baseline of the fifth-order polynomial extremes by a maximum of 48%. Interestingly, the deviation between theoretical and experimental values increases with decreasing power frequency. These results are evidence of the theoretical overestimation of energy efficiency of an AMF adjusted by a VFD.","PeriodicalId":44166,"journal":{"name":"Mining Technology-Transactions of the Institutions of Mining and Metallurgy","volume":"13 1","pages":"186 - 191"},"PeriodicalIF":1.1,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77387666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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