To see the other types of publications on this topic, follow the link: Hydraulic mining.
Dissertations / Theses on the topic 'Hydraulic mining'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 32 dissertations / theses for your research on the topic 'Hydraulic mining.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
El-Alfy, Sadek E. "Hydraulic mining in cold regions." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270485.
Full text
2
Stark, Aimee Lizabeth. "Characterization of sand processed for use in hydraulic fracture mining." Thesis, University of Iowa, 2016. https://ir.uiowa.edu/etd/3195.
Full textAbstract:
Each hydraulic fracturing well uses up to 5,000 tons of silica-containing sand, or proppant, during its operational lifetime. Over one million wells are currently in operation across the continental United States. The resulting increase in demand resulted in the production of 54 million metric tons of sand for use as hydraulic fracturing proppant in 2015.
The goal of this study was to determine the relative risk of occupational exposure to respirable crystalline silica to workers performing tasks associated with mining, processing, and transport of proppant. Sand samples were aerosolized in an enclosed chamber. Bulk and respirable samples were submitted to a commercial lab for silica analysis. A risk ratio was calculated by comparing respirable dust concentrations to the current occupational safety regulations.
Raw sand produced higher concentrations of respirable dust and a higher risk ratio (3.2), while processed dust contained higher percentages of respirable crystalline silica but a lower risk ratio (0.5). When vibration was introduced prior to aerosolization, concentrations tended to increase as vibration times increased, resulting in an increase of the associated risk ratio (2.3). Results of the study indicate that workers in sand mines and workers exposed to proppant that has undergone low-frequency vibration are at increased risk of exposure to respirable crystalline silica compared to workers who are exposed to proppant that has not undergone vibration.
3
Hamilton, James F. "A study of the fine gold recovery of selected sluicebox configurations." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28384.
Full textAbstract:
The recovery of placer gold from 20 mesh to 150 mesh in common sluicebox configurations was investigated. Two types of riffles, 1-10H expanded metal (1.5"x.75"x.25") and 1.25" angle iron riffles (dredge riffles), were used in conjunction with 3/8" thick "Nomad" matting for 25 tests. The effects of variations in upper feed size, water flow rate, sluice gradient, and solids feed rate on the recovery of placer gold particles are documented.
The gold and test gravel were obtained from the Teck Corporation sluicing operation on Sulphur Creek, Yukon Territory during July, 1985. Approximately nine troy ounces of placer gold and fifteen tons of gravel were transported to Vancouver.B.C. A test sluice facility was constructed in Coquitlam,B.C. to simulate operating conditions in a typical Yukon placer operation. The sluicebox was 12" wide and 8' long with clear plexiglass sidewalls. Screened gravel of either 3/4" or 1/4" upper feed size was fed to this sluice from a hopper at rates of up to 1260 lb/min. The water pumping capacity was a maximum of 400 USGPM. Between 75 and 90 grams of each of three sizes of placer gold (-20+28#, -35+48#, -65+100# ) were premixed with the gravel for most tests. The final test used 25 grams of -100+150 mesh gold.
Sluicing, when properly controlled, was found to be a highly effective means of concentrating placer gold as small as 150 mesh. Expanded metal riffles were far superior to dredge riffles in concentrating gold of this size range. Recovery of the -65+100# size fraction frequently exceeded 90% when using expanded metal riffles. Visual observation of eddies formed downstream of the riffles showed that scour depth between riffles was the one characteristic of the slurry flow that gave the best indication of the resulting gold recovery. For expanded metal, scour depths between 1/2 and 3/4 of the riffle depth were found the most effective.Applied Science, Faculty of
Mining Engineering, Keevil Institute of
Graduate
4
Bigby, D. N. "The influence of hydraulic powered support on the behaviour of strata around longwall coalfaces." Thesis, Bucks New University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373577.
Full text
5
Altamirano-Soto, Pablo, Jorge Supa-Urrutia, Humbero Pehovaz-Alvarez, Carlos Raymundo, Nestor Mamani-Macedo, and Francisco Dominguez. "Filling Method Implementing Hydraulic Lime for Reusing Mine Tailings and Improve Sustainability in Conventional Peruvian Underground Mines." Springer, 2020. http://hdl.handle.net/10757/656169.
Full textAbstract:
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.Mining in Peru has existed for several decades, and for several years, there has been no proper environmental management of the impact of this activity on the environment and society in general, whether it be gas emissions, the presence of acidic water, or the generation of mining tailings. One of the most prominent examples involve mine tailings; these are by-products of mining processing plants and are stored in a dam known as a tailings dam. Like any extraction activity, mining generates large amounts of waste material that could become potential risks to the environment and society. Using hydraulic fills, the mine tailings contained in tailings dams could be reused. These fills seek to decrease the volume of stored tailings to prevent any future dam collapses, as observed in Brazil with the Vale mining company, where its tailings dam collapsed and caused more than 200 deaths.
6
Andersson, Carl. "A bonded discrete element approach to simulate loading with hydraulic mining excavators." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-84845.
Full textAbstract:
When operating hydraulic mining excavators the loading equipment is exposed to harsh conditions which lead to extensive wear of the equipment, especially the bucket and bucket teeth. Simulations are used to better understand the wear development and to evaluate new methods to operate excavators more efficiently. At the Aitik mine, operated by the high-tech metal company Boliden Mines, hydraulic excavators are used when loading the mined ore. One of the hydraulic excavators used at Aitik is the Komatsu PC7000. In this master thesis, a simulation model for the hydraulic excavator Komatsu PC7000 was developed with the simulation software LS-DYNA. This model consists of multi rigid body dynamics to describe the motion of the excavator and a granular material model to describe the rocks loaded into the bucket of the excavator. Simulations with two different types of granular material models have been utilized to study the wear development of the bucket. One of the models (bonded DE model) uses bonded discrete elements to describe the large rocks and single discrete elements are used to describe smaller rocks. This model is compared to the current FE-DE model which is being used today at Boliden. This model uses finite elements (FE) to model the larger rocks and discrete element spheres (DES) for smaller rocks. By using the bonded DE method a 71\% reduction in simulation time could be achieved. This can be partly explained by the reduction of the number of elements included in the rock pile. Archard's wear law was used to numerically describe the wear development of the bucket. When simulating the wear a total of 30 bucket fillings were performed with the excavator. This was done with both the bonded DE method and the FE-DE method. In this wear study, the inside of the bucket was of interest. The resulting simulated wear map was compared to experimental measurements from which the plate thickness of the bucket had been measured two times to obtain the wear depth of some points inside the bucket. The experimental measurements and two 3D scanned point clouds were used to determine the wear depth inside the bucket. Results from the simulation showed that the wear is concentrated to the center of the bucket while less wear is concentrated to the sides of the bucket. With the bonded DE method the wear appeared to be more evenly distributed inside the bucket while the wear from the FE-DE method appeared in spots inside the bucket. The experimental results also showed that the wear was more extensive in the center of the bucket and also in the back of the bucket. Both simulation methods also showed that the wear was concentrated to the back of the bucket. From the simulations, it was also seen that the behavior of the material flow differed between the two methods. In the bonded DE method the material flow had more sliding behavior while the material flow in the FE-DE method had more rolling behavior. This could also be the reason why the bonded DE method captures the wear more evenly. The rolling behavior seen in the FE-DE method leads to more impact wear which is not captured by Archard's wear law. Overall, the bonded DE method leads to a big reduction in simulation time which is favorable when it comes to simulation. The larger rocks will have simpler shapes without sharp corners. However, the method allows for a more complex shape than just an ordinary sphere which is the simplest and most common shape to describe granular material. The bonded DE method also allows for easier configuration of contact definition since fewer contact interfaces must be added to the model. Furthermore, the post-processing of wear in LS-DYNA was facilitated since the wear does not have to be divided into two wear collectors for FE elements and DE elements.
7
Edwards, David John. "A methodology for predicting the total average hourly maintenance cost of tracked hydraulic excavators operating in the UK opencast mining industry." Thesis, University of Wolverhampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268092.
Full textAbstract:
Research into the financial management of construction plant and equipment maintenance is scant, despite the increased utilisation of mechanisation to augment productivity in recent years. This thesis addresses the shortage of meaningful research by developing a methodology for predicting the total average hourly maintenance costs of tracked hydraulic excavators operating in opencast mining. Initial pilot and field studies conducted revealed that maintenance management (in the form of record keeping and attitude to used oil analysis) within the plant hire and general construction industry was generally poor. Hence, the decision was made to focus the research upon plant operated by opencast mining contractors. Here, plant managers were found to utilise an optimum blend of predictive and fixed-time-to maintenance and also maintain a depth of machine history file data. Modelling total maintenance costs using multiple regression (MR) analysis at the five percent level of significance identified four key predictor variables. These were: machine weight; attitude to used oil analysis (regular use or not); type of industry (opencast coal or slate); and type of machine (backacter or front shovel). However, in order to determine the model's robustness an alternative modelling technique, namely artificial neural networks (ANN) was applied using the same variables identified as significant predictor variables in the regression analysis. Performance analysis conducted on the predictive power of both MR and ANN models revealed that overall the ANN model exhibited greater predictive performance. The thesis concludes with direction for future research and moreover, identifies the need for a more fastidious approach to maintenance management.
8
Dunn, Matthew Thomas. "Design of a mixing unit for oil-in-water emulsions for hydraulic systems in underground mining." Thesis, Queensland University of Technology, 1997. https://eprints.qut.edu.au/36016/1/36016_Dunn_1997.pdf.
Full textAbstract:
The thesis details the design, development and implementation of a proportional mixer unit to
mix emulsions in longwall mining applications.
The principal aim of this thesis was to reduce the maintenance costs, down-time, and loss of
production due to failure of the hydraulic roof support system in longwall mining. Improved
operation can be achieved by increasing the control and reliability of the hydraulic fluid
system.
The present state of technology was reviewed in the metering and mixing systems such as:
gear pumps and gear motors, venturi type, proportioning piston and metering pumps.
Historical data showed that these systems could not provide a reliable and consistent output.
Each of the systems were analysed to determine the operating characteristics, strengths,
weaknesses and potential areas for improvements. From this analysis the venturi system was
chosen as a base system for further development.
The greatest weakness of the venturi system was its inability to cope with changes in the
operating conditions. To overcome this limitation a proportional controller was designed and
built to attach directly to a venturi mixer unit. The basis of the improvement was similar to
that used in conventional hydraulic systems for pressure compensated flow control.
Laboratory test results indicated that the device would function effectively, giving consistent
concentrations of emulsions under various operating conditions. The system was installed for
a period of 2 months in a colliery located in the Hunter Valley. Records of the tests were kept
on a daily basis. The device was removed after the test period and examined for wear and
other factors that may have influenced the perf 01mance of the controller unit.
The results indicated the device functioned c01Tectly, in that it held the output concentration at
the desired level for an extended operating period A visual inspection and performance tests were undertaken after the field trials. The results
revealed that the device was :functioning as it was designed. There were no signs of
component degradation due to excessive mechanical or corrosive wear.
9
Bailey, John L. "Evaluation of fish and benthic invertebrate bioassessments and the effects of placer mining on Yukon River Basin streams." Restricted access (UM), 2008. http://libraries.maine.edu/gateway/oroauth.asp?file=orono/etheses/37803141.pdf.
Full textAbstract:
Thesis (Ph. D.)--University of Western Ontario, 2008.Includes Vita. Title from PDF title page (viewed on May 25, 2010) Available through UMI ProQuest Digital Dissertations. Includes bibliographical references (leaves 86-89). Also issued in print.
10
Gustavsson, Daniel, and Jakob Wallin. "Simulering av hydrauliska dämpare i borrslagverk." Thesis, Linköping University, Department of Management and Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10626.
Full textAbstract:
This master thesis consists of the creation of shock absorber models for percussive rock drills. A model of the rock was also developed. These models were connected to existing models of the rock drill to create a complete simulation of the rock drilling process.
When the models had been created the rock model was evaluated by comparison with measured values from lab tests. The verified rock model was then used to evaluate the shock absorber models.
Four new shock absorber concepts have been developed. Three of these have been modelled, while the fourth have only been sketched and described.
The evaluation of the models showed the following:
• Simulations of the single shock absorber don’t correlate to reality very well. The movement is too rapid and poorly damped.
• The simulated behaviour of the tandem shock absorber corresponds to reality, but the simulated hydraulic pressures aren’t reliable and neither is the damping.
• Simulation of the double shock absorber reflects reality fairly well, although the model of the check valve can be improved.
• There are problems with fluttering damper pressures in simulation whenever an accumulator is connected directly to the damper volume. The problem doesn’t exist if there is a line or an orifice with enough losses between the volume and the accumulator.
• The feeder system needs to be modelled.
Examensarbetet gick ut på att ta fram simuleringsmodeller av olika dämpare i en bergborrmaskin. Dessutom behövdes en bergmodell som gav korrekta reflexer från berget vid simulering. Dessa modeller kopplades samman med befintliga modeller för att skapa en simulering av hela bergborrningsprocessen.
Efter att modeller skapats utvärderades bergmodellen mot mätvärden som uppmätts under prov. Efter att bergmodellen verifierats användes den för att verifiera dämparmodellerna.
Fyra dämparkoncept har tagits fram. Tre av dessa har modellerats, medan det fjärde endast har skissats och förklarats.
Verifieringen av modellerna visade följande:
• Simulering av enkeldämpare stämmer dåligt med verkligheten utan ger för snabba och odämpade rörelser.
• Simulering av dubbeldämparen stämmer bra med verkligheten men modellen över backventilen behöver ses över något.
• Simulering av tandemdämpare stämmer beteendemässigt men de simulerade trycken är inte tillförlitliga och inte heller dämpningen.
• Det finns problem med trycksvängningar vid simulering av modeller där dämpvolymen är direkt ansluten till en ackumulator. Om en strypning eller en ledning med tillräckliga förluster ansluter ackumulator och dämpvolym med varandra märks inte detta problem.
• Modell över matningen behöver tas fram.
11
Berges, B. J. P. "Acoustic detection of seabed gas leaks, with application to Carbon Capture and Storage (CCS), and leak prevention for the oil and gas industry." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/379746/.
Full textAbstract:
The acoustic remote sensing of subsea gas leakage, applied to the monitoring of underwater gas discharges from anthropogenic and natural sources, is becoming increasingly important. First, as the oil and gas industry is facing increasing regulation, there is a need to put more control in the industrial process and to assess the impact on the marine environment. The applications are diverse, including: early warnings of "blow-out" from offshore installations, detection of leaks from underwater gas pipelines, gas leakage detection from Carbon and Capture and Storage facilities (a process aimed at mitigating the release of large quantities of CO2 in the atmosphere), and seabed monitoring. Second, this technology has a role to play in oceanography for a better understanding of natural occurrences of gas release from the sea floor such as methane seeps. This is of major importance for the assessment of the exchange of gas between the ocean and the atmosphere with application to global warming. All those phenomena involve the formation and release of bubbles of different sizes. These are strong sources and scatterers of sound. Within this context, this thesis draws on a two part study. The first part experimentally addresses the accuracy of a passive acoustic inversion method for the quantification of gas release. Such a technique offers the advantage of lower power requirements for long term monitoring. It is common practice for researchers to identify single bubble injection events from time histories or time frequency representations of hydrophone data, and infer bubble sizes from the centre frequency of the emission. This is well suited for gas release at a low flow rate, involving solitary bubble release. However, for larger events, with overlapping of bubble acoustic emissions, the inability to discriminate each individual bubble injection events makes this approach inappropriate. Using an inverse method based on the spectrum of the acoustic emissions allows quantification of such releases with good accuracy. The inverse scheme is tested using data collected in a large test tank and data collected at sea during the QICS (Quantifying Impacts of Carbon Storage) project. The second part of the thesis addresses the problem of quantifying gas releases using active acoustics. Single beam echosounders are commonly used instruments in fisheries acoustics. When investigating gas release from the seafloor, they are frequently employed to study the spatial distribution of the gas releases. However, few studies make use of these data to quantify the amount of gas being released. Here, using the common multi-frequency ability of these systems, an inverse method aimed at determining gas volumes is developed. This is tested against simulated data and the method shows good performances in scenarios with limited data sets (data collected at limited number of frequencies). Then, using data collected at sea from methane seeps to the west of Svalbard (from two research cruises), the method is applied and compared to independent measurements of gas fluxes.
12
Portocarrero-Urdanivia, Cristhian, Angela Ochoa-Cuentas, Luis Arauzo-Gallardo, and Carlos Raymundo. "Hydraulic Fill Assessment Model Using Weathered Granitoids Based on Analytical Solutions to Mitigate Rock Mass Instability in Conventional Underground Mining." Universidad Peruana de Ciencias Aplicadas (UPC), 2021. http://hdl.handle.net/10757/653789.
Full textAbstract:
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.This study uses analytical solutions to assess a hydraulic fill model based on weathered granitoid to increase underground opening stability and mitigate rock bursts during mining operations in a conventional underground mining company located in the Coastal Batholiths of the Peruvian Andes. This study assesses the previous geological database provided by the mine, analyzes the on-site strengths produced by the exploitation works that will subsequently be filled, identifies the quality of the material used in the landfill (granitoids) through laboratory tests, and compares compressive strength at different depths, all contemplated within the landfill model used. This study focuses on the applicability of hydraulic fills in conventional underground mine using natural geological material such as granitoid.
Revisión por pares
13
Järschel, Theresa, and Jörg Willecke. "Maßnahmenplanung gemäß EG-WRRL Kleine Spree." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-85299.
Full textAbstract:
Mit landschaftsplanerischen und wasserbaulichen Maßnahmen soll die Kleine Spree gemäß EG-WRRL einen guten Zustand erreichen. Das 40 km lange Nebengewässer der Spree ist stark vom Braunkohlenbergbau beeinflusst. Der Bericht beschreibt und bewertet den Ist-Zustand der Kleinen Spree, analysiert die Defizite und leitet die Maßnahmen für einen guten ökologischen Zustand ab.
Für die Gewässerabschnitte wurden Pläne zur Renaturierung im Maßstab von 1:10.000 erstellt. Sie basieren auf dem Strahlquellen- und Trittsteinprinzip, bei dem ökologisch gute und sehr gute Abschnitte so im Gewässerverlauf platziert werden, dass die Strahlwirkung das gesamte Gewässer umfasst.
14
Dumpleton, Stephen. "The effects of coal mining on some hydraulic properties of the Sherwood Sandstone and Drift in the Selby area, North Yorkshire." Thesis, University of Sheffield, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390771.
Full text
15
Zhang, Qian. "Use of Time Series Analysis to Evaluate the Impacts of Underground Mining on Hydrological Properties of Dysart Woods, Ohio." Ohio University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1282225890.
Full text
16
Bleby, Timothy Michael. "Water use, ecophysiology and hydraulic architecture of Eucalyptus marginata (jarrah) growing on mine rehabilitation sites in the jarrah forest of south-western Australia." University of Western Australia. School of Plant Biology, 2003. http://theses.library.uwa.edu.au/adt-WU2004.0004.
Full textAbstract:
[Truncated abstract. Please see the pdf format for the complete text. Also, formulae and special characters can only be approximated here. Please see the pdf version for an accurate reproduction.] This thesis examines the water use, ecophysiology and hydraulic architecture of Eucalyptus marginata (jarrah) growing on bauxite mine rehabilitation sites in the jarrah forest of south-western Australia. The principal objective was to characterise the key environment and plant-based influences on tree water use, and to better understand the dynamics of water use over a range of spatial and temporal scales in this drought-prone ecosystem. A novel sap flow measurement system (based on the use of the heat pulse method) was developed so that a large number of trees could be monitored concurrently in the field. A validation experiment using potted jarrah saplings showed that rates of sap flow (transpiration) obtained using this system agreed with those obtained gravimetrically. Notably, diurnal patterns of transpiration were measured accurately and with precision using the newly developed heat ratio method. Field studies showed that water stress and water use by jarrah saplings on rehabilitation sites were strongly seasonal: being greatest in summer when it was warm and dry, and least in winter when it was cool and wet. At different times, water use was influenced by soil water availability, vapour pressure deficit (VPD) and plant hydraulic conductance. In some areas, there was evidence of a rapid decline in transpiration in response to dry soil conditions. At the end of summer, most saplings on rehabilitation sites were not water stressed, whereas water status in the forest was poor for small saplings but improved with increasing size. It has been recognised that mature jarrah trees avoid drought by having deep root systems, however, it appears that saplings on rehabilitation sites may have not yet developed functional deep roots, and as such, they may be heavily reliant on moisture stored in surface soil horizons. Simple predictive models of tree water use revealed that stand water use was 74 % of annual rainfall at a high density (leaf area index, LAI = 3.1), high rainfall (1200 mm yr-1) site, and 12 % of rainfall at a low density (LAI = 0.4), low rainfall (600 mm yr-1) site, and that water use increased with stand growth. A controlled field experiment confirmed that: (1) sapling transpiration was restricted as root-zone water availability declined, irrespective of VPD; (2) transpiration was correlated with VPD when water was abundant; and (3) transpiration was limited by soil-to-leaf hydraulic conductance when water was abundant and VPD was high (> 2 kPa). Specifically, transpiration was regulated by stomatal conductance. Large stomatal apertures could sustain high transpiration rates, but stomata were sensitive to hydraulic perturbations caused by soil water deficits and/or high evaporative demand. No other physiological mechanisms conferred immediate resistance to drought. Empirical observations were agreeably linked with a current theory suggesting that stomata regulate transpiration and plant water potential in order to prevent hydraulic dysfunction following a reduction in soil-to-leaf hydraulic conductance. Moreover, it was clear that plant hydraulic capacity determined the pattern and extent of stomatal regulation. Differences in hydraulic capacity across a gradient in water availability were a reflection of differences in root-to-leaf hydraulic conductance, and were possibly related to differences in xylem structure. Saplings on rehabilitation sites had greater hydraulic conductance (by 50 %) and greater leaf-specific rates of transpiration at the high rainfall site (1.5 kg m-2 day1) than at the low rainfall site (0.8 kg m-2 day1) under near optimal conditions. Also, rehabilitation-grown saplings had significantly greater leaf area, leaf area to sapwood area ratios and hydraulic conductance (by 30-50 %) compared to forest-grown saplings, a strong indication that soils in rehabilitation sites contained more water than soils in the forest. Results suggested that: (1) the hydraulic structure and function of saplings growing under the same climatic conditions was determined by soil water availability; (2) drought reduced stomatal conductance and transpiration by reducing whole-tree hydraulic conductance; and (3) saplings growing on open rehabilitation sites utilised more abundant water, light and nutrients than saplings growing in the forest understorey. These findings support a paradigm that trees evolve hydraulic equipment and physiological characteristics suited to the most efficient use of water from a particular spatial and temporal niche in the soil environment.
17
Ruhm, Catherine Terese. "The Effects of Two Types of Reclamation on Abandoned Non-Coal Surface Mines in Cuyahoga Valley National Park, Ohio." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1543876471411951.
Full text
18
Minav, Tatiana, Matti Pietola, Teemu Lehmuspelto, and Panu Sainio. "Series Hybrid Mining Loader with Zonal Hydraulics." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-200498.
Full textAbstract:
Presently, there is a four-year window to prepare engines for upcoming TIER V regulations through solutions for peak power shaving and downsizing of diesel engines. In particular, Non-road mobile machinery(NRMM) offer a promising and challenging field of application due to their duty cycles, which includes high and short power peaks and extreme working conditions. In this paper, a series hybrid electric powertrain for a mining loader is presented with the goal of reducing the fuel consumption. A full-scale mining loader powertrain prototype was built to exploit the benefits of a series hybrid electric powertrain at low traction requirements with a combination of decentralized e.g. zonal hydraulics. Corespondingly, this paper introduces the structure of the mining loader and initial mathematical model of the system of a Direct Driven hydraulics (DDH). In this research, an experimental test was conducted, and the initial results are presented in this paper.
19
Dogan, Huseyin Ali. "Investigation Of Bit Hydraulics For Gasified Drilling Fluids." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/12604906/index.pdf.
Full textAbstract:
Accurate determination of the pressure losses at the bit is very important for drilling practices in petroleum industry. In the literature, there are several studies on determination of the pressure losses. Major focus is concentrated on single phase drilling fluids, which is far from accurate estimation of pressure losses for multiphase fluids, i.e., fluids including a liquid and a gas phase, at the bit. Some of these models are valid for multiphase fluids, however, they are either valid for very high gas flow rates, or developed using very strong assumptions.
This study presents a mathematical model for calculating bit hydraulics for gasified drilling fluids. The theory, which is valid for both sonic (critical) and subsonic (sub-critical) regimes, is based on the solution of the general energy equation for compressible fluid flow. The model is sensitive to changes in internal energy, temperature and compressibility. In addition, the model uses &ldquomixture sound velocity&rdquo
approach. A computer program is developed based on the proposed mathematical model. The program calculates pressure drop through a nozzle in subsonic flow region, and suggest flow rate if the calculated pressure drop values is in the sonic flow pressure ranges. The program has been run at reasonable field data. The results of the models have been compared with the results of existing models in the literature. The results show that the pressure losses through the bit can be estimated with a variation less than 9%. Also, it has been observed that bottom hole pressure, velocity of the liquid phase and nozzle size have a strong influence on bit pressure drop.
20
Kyprianou, Andreas. "Non-linear parameter estimation of dynamic models using differential evolution : application to hysteretic systems and hydraulic engine mounts." Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310943.
Full text
21
Nožka, Michal. "Řízení hydraulických rozváděčů miniexkavátoru." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-442674.
Full textAbstract:
This diploma thesis deals with the design of control algorithm for hydraulic directional control valves of a zero-emission mini excavator. Zero emission excavator have same parameters as diesel engine powered version of it. To solve this problem simulations were done for hydraulics and control algorithm of this machine. To find right parameters of simulation models, experiments have been done. There were also proposed some methods to obtain the right set of parameters. The result of this diploma thesis is control algorithm for directional control valves of this very unique mini excavator that doesn't have any competitor (in terms of control algorithm). Set of parameters was also tested during experiments.
22
Villines, Jonathan A. "USING GIS TO DELINEATE HEADWATER STREAM ORIGINS IN THE APPALACHIAN COAL-BELT REGION OF KENTUCKY." UKnowledge, 2013. http://uknowledge.uky.edu/bae_etds/15.
Full textAbstract:
Human activity such as surface mining can have substantial impacts on the natural environment. Performing a Cumulative Hydrologic Impact Assessment (CHIA) of such impacts on surface water systems requires knowing the location and extent of these impacted streams. The Jurisdictional Determination (JD) of a stream’s protected status under the Clean Water Act (CWA) involves locating and classifying streams according to their flow regime: ephemeral, intermittent, or perennial. Due to their often remote locations and small size, taking a field inventory of headwater streams for surface mining permit applications or permit reviews is challenging. A means of estimating headwater stream location and extent, according to flow regime using publicly available spatial data, would assist in performing CHIAs and JDs. Using headwater point-of-origin data collected from Robinson Forest in eastern Kentucky along with data from three JDs obtained via a Freedom of Information Act (FOIA) request to the U.S. Army Corps of Engineers (USACE), headwater streams in the Appalachian Coal Belt were characterized according to a set of spatial parameters. These characteristics were extrapolated using GIS to delineate headwater streams over a larger area, and the results were compared to the National Hydrography Dataset (NHD).
23
Ghosh, Rajib. "Assessment of rock mass quality and its effects on charge ability using drill monitoring technique." Doctoral thesis, Luleå tekniska universitet, Geoteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-65584.
Full text
24
Silva, Daniela Villa Flor Montes Rey. "Implantação de técnica para determinação de parâmetros hidráulicos e de transporte de solutos em solos visando a aplicação em simulação computacional de migração de contaminantes." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263461.
Full textAbstract:
Orientador: Marcio Luiz de Souza-SantosTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
Made available in DSpace on 2018-08-16T10:15:10Z (GMT). No. of bitstreams: 1 Silva_DanielaVillaFlorMontesRey_D.pdf: 4784626 bytes, checksum: 2c07a9198d76af68b1571651aa00046a (MD5) Previous issue date: 2010
Resumo: Este trabalho tem por objetivo a implantação de uma técnica para estimativa simultânea dos parâmetros hidráulicos e de transporte de solutos em solos, visando a aplicação em simulação computacional de migração de contaminantes. Foi selecionado um aparato experimental para a realização do experimento de transporte de soluto em colunas, assim como o código Hydrus-1D para estimativa de parâmetros através da Técnica de Levenberg-Marquard. Para testar o método foi utilizado um solo arenoso não-reativo. Com esse material foram estimados o conteúdo de água de saturação qs, a condutividade hidráulica de saturação Ks e o coeficiente de dispersão D. Foram testadas quatro estratégias para a estimativa onde os parâmetros foram estimados simultaneamente e separadamente em ordens diversas. As estratégias que fazem a estimativa dos parâmetros separadamente apresentaram melhores resultados. Foi avaliada também a influência das dimensões das colunas nos resultados experimentais e nos resultados das estimativas, demonstrando que colunas de menor comprimento apresentam resultados melhores e que houve uma variação nos resultados devido à variação no diâmetro, o que está em desacordo com o modelo unidimensional utilizado. Em seguida amostras de solo da mina de urânio de Caldas foram testadas. Para este material foram estimados os mesmos parâmetros anteriores mais o coeficiente de distribuição Kd. Os valores estimados para os parâmetros com o solo da mina de urânio apresentaram pequenos desvios-padrão, caracterizando boas estimativas
Abstract: The objective of this work is to implement a technique for the simultaneous estimation of hydraulic and transport parameters of soils, aiming at the application on computational simulation of contaminant migration. An adequate experimental apparatus was selected for the solute transporte experiment in small columns. The software Hydrus-1D was selected as the simulation software capable of estimating the parameters through the Levenberg-Marquardt Technique. For the implementation of the methodology a non-reactive sandy soil was used. The saturation water content qs, the saturation hydraulic conductivity Ks and the dispersion coefficient D were estimated for this material. Four approaches were tested, including simultaneous and sequential estimations in various orders. The sequential estimation resulted in better results. The influence of the dimensions of the columns on the experimental and estimation results was also evaluated, demonstrating that columns with smaller high results in better estimations and that the diameter variations resulted in variation of the behavior, in disagreement with the unidimensional model used. Next, soil samples extracted from de Caldas uranium mine were used for the estimation of the same parameters together with the distribution coefficient Kd. Values for the estimated parameters with the soil samples from the uranium mine showed small standard deviations, characterizing good estimations
Doutorado
Termica e Fluidos
Doutor em Engenharia Mecânica
25
Schlothmann, Daniel. "Kurz- und langfristige Angebotskurven für Rohöl und die Konsequenzen für den Markt." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2016. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-201396.
Full textAbstract:
In dieser Arbeit wurden Angebotskurven für 22 bedeutende Ölförderländer ermittelt und anschließend zu globalen Angebotskurven aggregiert. Gemäß den ermittelten Angebotskurven sind nahezu alle gegenwärtig in der Förderphase befindlichen Ölprojekte in den Untersuchungsländern auch beim aktuellen Ölpreis von 35 bis 40 US-$ je Barrel unter Berücksichtigung der kurzfristigen Grenzkosten rentabel. Sollte der Ölpreis jedoch in den kommenden Jahren auf diesem Niveau verharren, wird es bis zum Jahr 2024 zu einem Angebotsengpass auf dem globalen Ölmarkt kommen, da zur Deckung der zukünftigen Nachfrage die Erschließung kostenintensiver, unkonventioneller Lagerstätten und von Lagerstätten in tiefen und sehr tiefen Gewässern notwendig ist. Damit es bis zum Jahr 2024 nicht zu einem solchen Angebotsengpass kommt, ist gemäß des ermittelten langfristigen Marktgleichgewichts ein Ölpreis von mindestens 80 (2014er) US-$ je Barrel notwendig.
26
QUARANTA, EMANUELE. "Investigation and optimization of the performance of gravity water wheels." Doctoral thesis, Politecnico di Torino, 2017. http://hdl.handle.net/11583/2674225.
Full textAbstract:
Water wheels are rotating hydraulic machines that were introduced thousands of years ago to generate energy from water. Gravity water wheels are driven by the weight of the water flow and a portion of the flow kinetic energy. In the last decades, due to the increasing diffusion of micro hydropower plants (installed power less than 100 kW), gravity water wheels are being recognized as attractive hydraulic machines to produce electricity. Unfortunately, most of the engineering knowledge on water wheels is dated back to the XIX century, with several gaps and uncertainty. Additional work is still needed to fully understand the power losses and the performance within water wheels, that could lead to further improvements in efficiency.
The scope of the present thesis is the investigation and improvement of the performance of gravity water wheels. This aim was achieved using physical experiments to quantify water wheels performance under different hydraulic conditions, theoretical models to estimate and predict the efficiency, and numerical simulations to optimize the design. Undershot, breastshot and overshot water wheels were investigated, in order to give a wide overview on all the kinds of gravity water wheels.
Sagebien and Zuppinger undershot wheels were investigated at Southampton University, under the supervision of prof. Gerald Muller, from October 2015 until April 2016. These two wheels differ based on the shape of the blades. The blades of Sagebien wheels are optimized to reduce the inflow power losses, while those of Zuppinger wheels are conceived to minimize the outflow power losses. The objective of the experiments was to understand which of the two designs is better in term of efficiency. The tests showed that the Sagebien type exhibits a more constant efficiency as a function of the flow rate and the hydraulic head than the Zuppinger type. The maximum efficiency (excluding leakages) was identified as 88%.
Breastshot water wheels were investigated experimentally, theoretically and using numerical Computational Fluid Dynamic (CFD) methods at Politecnico di Torino. The maximum experimental efficiency was estimated as 75% using a sluice gate inflow. A vertical inflow weir was also investigated, and found to have a more constant efficiency versus the rotational speed of the wheel, but with similar maximum values. A theoretical model that was developed to estimate the power output, power losses and efficiency, had a discrepancy with the experiments of 8%. A dimensionless law was also developed to estimate the power output. Numerical CFD simulations were performed to understand the effects of the number and shape of the blades on the efficiency. The optimal number of blades was 48 for the investigated wheel, and the efficiency can be improved using a circular shape. The numerical discrepancy with experiments was less than 6%.
Overshot water wheels were investigated using a similar approach as done for breastshot wheels, and were found to have a maximum experimental efficiency of 85%. A theoretical model was developed to estimate the power losses and the efficiency, in particular to quantify the volumetric losses at the top of the wheel, that is the fraction of the flow which can not enter into the buckets and that is lost. Then, numerical simulations will be started to try to improve the wheel efficiency, reducing the previous volumetric losses. More specifically, a circular wall around the periphery of the wheel was added to the original design, leading to a performance improvement up to 60%.
The results of this work show that water wheels can be considered attractive hydropower converters.
27
Makusa, Gregory Paul. "Mechanical properties of stabilized dredged sediments : for sustainable geotechnical structures." Licentiate thesis, Luleå tekniska universitet, Geoteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17437.
Full textAbstract:
Dredging activities at Ports and Harbors are inevitable for the safe navigation of ships and vessels. Dredged material may range from very fine and contaminated sediments to sand and gravels. While, granular dredged material can be directly utilized in civil engineering applications, fine sediments may require further treatment before use. In geotechnical context, fine sediments are characterized by low shear strength and high compressibility. However, these unfavorable properties do not rule out the suitability of these fine dredged sediments for use in geotechnical construction, such as, road embankment, building foundation or as structural backfill in land reclamation. Mass stabilization solidification provides a comprehensive technology for amending fine sediments at high initial water content, resulting into construction materials of improved strength and reduced compressibility. The ultimate in-situ soil behavior types, stiffness and strength properties of stabilized mass depend on various factors such as binders, mixing equipment, curing temperature, in-situ boundary conditions and mostly important the applied preloading weight during the period of curing. However, despite improved mechanical properties for geotechnical applications, the performance of treated materials becomes susceptible to repeated freeze-thaw cycles. Understanding geotechnical design process, which includes evaluation of material properties, loading condition and selection of appropriate constitutive model, is an important task for settlement and stability analysis of structures founded on stabilized mass. The selection of suitable material model is vital for successful finite element analysis. Nevertheless, among all existing constitutive soil models, none of them can capture all aspects of soil behavior. Therefore, the meaningful and quantifiable predictions of field behaviors are possible only if, undisturbed samples or in-situ tests are used for determination of mechanical properties, and the predictive capacity of selected constitutive model comes from the comparison with field observations In the present research work, utilization of cone penetration test (CPT) data for evaluating the mechanical properties of stabilized dredged sediments for geotechnical design and analysis was presented. A large-scale field test at the Port of Gävle was utilized as a case study, to verify the simulated settlement of preloaded stabilized dredged sediments. The stabilized mass–soil classification behavior type was studied utilizing CPT classification charts. Computation of the primary consolidation settlement due to preloading weight were carried out in PLAXIS 2D geotechnical software and verified against field measurements. A suggestion to protect the stabilized mass against severe weather condition was discussed.Godkänd; 2013; 20130409 (makusa); Tillkännagivande licentiatseminarium 2013-04-25 Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Gregory Paul Makusa Ämne: Geoteknik/Soil Mechanics and Foundation Engineering Uppsats: Mechanical Properties of Stabilized Dredged Sediments for Sustainable Geotechnical Structures Examinator: Professor Sven Knutsson, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Civ.ing. Forskningsdirektör Göran Holm, Statens Geotekniska Institut, Linköping Tid: Torsdag den 16 maj 2013 kl 10.00 Plats: F1031, Luleå tekniska universitet
28
Gibbs, John H. "Actuated Continuously Variable Transmission for Small Vehicles." University of Akron / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=akron1238819759.
Full text
29
Badarudeen, Sharon A. "Flow characteristics study of fly ash slurry in hydraulic pipelines using computational fluid dynamics." Thesis, 2014. http://ethesis.nitrkl.ac.in/6498/1/212MN1463_-12.pdf.
Full textAbstract:
Transportation of fly ash slurry via pipelines has been recognized as a potential economical and dependable mode of solid transportation. It also bids various other advantages over the conventional means of transportation. For improved understanding of the flow characteristics of these pipelines, investigators throughout the world have been analyzing the flow experimentally numerically and theoretically. Slurry pipeline systems are regularly used crosswise the world for the transportation of fly ash from the power plant to the ash ponds. These pipeline are very much energy exhaustive and also leads to disproportionate and inordinate wear of pipelines and wastage of water. Objective of the present work is to conduct a methodical and logical study of fly ash slurry transportation in a pipeline at higher concentrations by the use of computational fluid dynamics and study the flow characteristics and pressure drops. An effort has been made in this study to develop comprehensive slurry flow model using CFD and utilize the model to predict pressure drop and validating the results with the calculated results. A broad computational fluid dynamics (CFD) model was established in the current study to gain understanding into the solid liquid slurry flow in pipelines. The approach adopted in here is studying and solving the problem by mathematical modeling method. In this work, the solid suspension in a fully developed pipe flow was simulated and analyzed A 20m pipe with a diameter of 0.5m is modeled, through which flow is conducted where modelling and meshing is done using ANSYS Fluent. High viscosity fly ash slurry with five different concentrations, 50%, 60%, 65%, 68% and 70% by weight of fly ash is passed and for each concentration five different velocities like 3, 3.5, 4, 4.5 and 5 m/s are used and pressure drops are calculated. Other characteristics studied are volume fraction, eddy viscosity and turbulence kinetic energy.
30
Fenn, Orrie. "The use of water jets to enhance the performance of free rolling cutters in hard rock." Thesis, 2015. http://hdl.handle.net/10210/13419.
Full textAbstract:
D.Ing.The research described in this thesis is an investigation into fundamental aspects of the mechanical excavation of hard rock using free rolling cutters, currently being undertaken at the Chamber of Mines of South Africa Research Organization. The motivation for undertaking this study was provided by the need to improve the effectiveness and operational efficiency of this type of tool with regards to its application in the South African gold mining industry. Earlier work has shown that the use of high-pressure water jets enhances the performance of mechanical cutting in hard rock. To assess the potential of this approach for use in conjunction with free rolling cutters, a series of laboratory tests was conducted using both disc and button type cutters, to determine the relative effects, on cutter performance, of variations in the relevant jet and cutting parameters. The parameters investigated were jet pressure, jet configuration, depth and spacing of cuts and cutting speed. Jets of diameter 1,2 mm were used singly and in combination of 2 and 4 jets at pressures in the range of 5 MPa to 40 MPa which gave flow rates of up to 0,3 lis per jet. Cut spacing, cut depth and cutting speed were varied between 15 mm and 90 mm, 2 mm and 6 mm, and 0,1 mls and 1,0 mls respectively. Tests were carried out on a linear rock cutting machine, purpose built according to specifications prepared from measurements made during underground field trials, which gave it the ability to test full-scale cutters under loading conditions representative of those found in the field. All the tests carried out were performed in the constant penetration, multiple pass (groove deepening) cutting mode, using dressed (smooth) and pre-conditioned (pre-roughened) rock surfaces.
31
Auret, Johannes Gerhardus. "Cavitation erosion : the effect of fluid and flow parameters." Thesis, 2016. http://hdl.handle.net/10539/21329.
Full textAbstract:
This thesis describes an investigation into the effect of fluid and flow parameters on
cavitation dynamics and cavitation erosion. A rotating disc test apparatus was developed
fo: dow-type cavitation studies. A vibratory test device was also developed to study the
role of cathodic and anodic potentials applied to cavitating bodies. Some major results
are given below.
Erosion "peaksat about 50°C in water, but under certain conditions material degradation
caused by increased corrosion rate cancels out thermodynamic effects at higher
temperatures. An erosion peak is also observed as a function of static pressure. Damage
increases with velocity until cavitation is fully developed, at which stage the influence of
velocity becomes negligible. The changes in erosion zone geometry and mass loss caused
by temperature, velocity and pressure variations may be correlated with the effect these
parameters have on the cavitation pressure profile. Efforts are described to develop a
system for measuring this profile in the rotating disc device.
Water quality including dissolved ions, as well as solid and gas impurities, influences both
cavitation inception and the amount of cavitation damage caused. The synergism
between cavitation erosion and corrosion causes high damage rates in corrosive,
cavitating liquids. Solid impurities at medium concentrations may enhance or retard
cavitation damage substantially, depending on the physical properties of the solid. Below
the saturation level, increasing concentration of dissolved air in water results in a slight
decrease in damage, but damage can be almost completely eliminated by the release of
air bubbles into the cavitation region.
Another important result is that the gas developed by the application of external
potentials to a cavitating body provides protection against cavitation erosion through a
gas cushioning mechanism. Cathodic protection of cavitating bodies will thus serve to
decrease damage rates even in the case of corrosion-resistant materials like stainlessGR 2016
32
Maripa, Mahlodi Ramsy. "Spatial variability of hydraulic properties as affected by physical properties of selected soil types in South Africa." Diss., 2019. http://hdl.handle.net/11602/1482.
Full textAbstract:
MSCAGRDepartment of Soil Science
Soil hydraulic and hydraulic-related physical properties are key to soil productivity and these properties are widely studied. Nevertheless, their spatial variability is least understood. Two sites were selected for this study (University of Venda Experimental farm and Roodeplaat, Agricultural Research Council farm). The objectives of this study were to determine the spatial variability of soil water content, water infiltration and hydraulic conductivity on selected soils. Field measurements were done on a 20 m × 20 m. Soil hydraulic and hydraulic-related physical properties were studied at two depths, 0 – 0.2 m top soil and 0.2 – 0.4 m sub soil. The field was irrigated to saturation and let to drain freely for two days. The soil was quickly secured in water cans to avoid further loss of water by evaporation and taken to the laboratory for analysis. Data was analysed using ordinary kriging method in ArcMap® software version 10.4 to generate spatial variability maps and semi variograms. The University of Venda Experimental farm had lesser spatial variability with coefficient of variation ranging from 9.6 to 33.4%. The spatial variability of soil was very low confirmed by contour maps depicting slightly homogeneity. Whereas, the soil hydro-physical properties displayed greater spatial variability at Roodeplaat, Agricultural Research Council Experimental farm. The empirical variograms of spherical model fits were also assuming weak spatial dependence with a curve variogram. The coefficient of variation ranged from 10.5 to 51.9%. Therefore, the greater variability at Roodeplaat, Agricultural Research Council Experimental farm indicated that coarse soil texture under conventional tillage has a greater influence on the spatial variability of the soil hydro-physical properties.
NRF