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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evaluation of Hydraulic Separator Applications in the Coal and Mineral Industries

Westerfield, Tracy Cheryl 09 November 2007 (has links)
The mineral processing industry has commonly utilized hydraulic separators throughout history for classification and gravity concentration of various minerals. More commonly referred to as hindered-bed or fluidized-bed separators, these units make use of differential particle settling rates to segregate particles according to shape, size, and/or density. As with any equipment, there are inefficiencies associated with its operation, which prompted an industry driven research program to further evaluate two novel high-efficiency hindered bed separators. These units, which are commercially called the CrossFlow separator and HydroFloat separator, have the potential to improve performance (separation efficiency and throughput) and reduce operating costs (power consumption, water and reagent usage). This thesis describes the results of recent laboratory and pilot-scale tests conducted with the CrossFlow and HydroFloat separators at several locations in the minerals and coal industries. Details of the testing programs (equipment setup, shakedown testing and detailed testing) associated with four coal plants and two phosphate plants are summarized in this work. In most of these applications, the high-efficiency units proved to provide a higher quality product at reduced costs when compared against the performance of conventional separators. As a result of this test work performed in this study, a full-scale CrossFlow separator is being installed at an industrial site. The separator is an integral part of an ultra-fine phosphate recovery system at a Florida processing plant. The unit will be used to classify the +400 mesh material prior to column flotation. The successful implementation of the ultra-fine phosphate recovery system will increase industry profits by the millions of dollars in addition to reducing tailing impoundments and energy requirements. / Master of Science
2

Investigating gas/solid separation using a novel compact inline separator

White, Tyrone January 1999 (has links)
Identified as an important issue for marginal fields, the removal of sand from hydrocarbon fluids has been investigated. A review of existing sand separation equipment has recognized a need for a new separator which will satisfy the design and performance requirements necessary for protecting offshore processing equipment. This thesis details the work and analysis undertaken which has contributed towards the design and development of a new offshore gas/solid separator. A critique of different separation techniques has identified axial flow cyclone (AFC) separators as a suitable separator design for offshore desanding applications. After reviewing existing models which simulate the performance of AFC separators a simple classification table has been developed. Using the conclusions of this review as a starting platform, a methodology for developing a new computational fluid dynamics (CFD) performance model for the new separator was proposed. Experimental work undertaken at the CALtec laboratories and the BG plc (formerly British Gas Research and Technology) Low Thornley test facilities are presented. The results obtained have been used to analysis the performance of difference separator internal designs. In addition, the results have been used to evaluate the robustness of existing AFC performance models and validate the new CFD model. For the investigated operational duties, the new CFD model has been shown to consistently under-predict the collection efficiency, whereas the other AFC models over-predict. From a design point of view, a model which under-predicts the overall collection efficiency will result in the over-design of the separator for a particular operating duty. Therefore, the use of such a model will ensure the design of a separator which will offer greater than expected levels of protection of downstream equipment from erosion wear.
3

Two phase flow in rapidly rotating porous media

Phillips, Andrew January 2003 (has links)
No description available.
4

Low Cost Common- and Differential-Mode Noise Diagnostic Circuit and Computer-Aided Design of Power Line Filter

Su, Hsin-Lung 19 June 2000 (has links)
Nowadays, electronics has really flourished with the rapid progress in science and technology. Besides being light and efficient of the products, digitalization and faster speed are also required which make the problem of EMI, electromagnetic interference, become more serious. Newer power supplies using switching technology become smaller and smaller. However, they also produce EMI problems that need to be considered. In this thesis, we only address the conducted EMI. Generally, the noise is suppressed by adding a filter at the power-line end. Hence, the EMI filter plays an important role to the solution of conducted emission. The particular filter is related to the type of the conducted emission, including common-mode and differential-mode. As a result, it is a great help for an engineer to be able to separate the noise. There are several noise separators in the present days. We propose new separators, which are capable of detect common-mode and differential-mode separately. Our separators are low-cost, easily manufactured and are able to give exact noise readings without adjustment. Incorporating the known methods of filter design and combing programming measurement the filter design can be made automatic. One approach makes use of the spectrum analyzer, which is considered to be a relatively expensive instrument. We also propose another approach using oscilloscope. The time-domain measurement is performed and transformed into frequency domain using FFT. A realistic design example is shown to give satisfactory results.
5

The tangential velocity profile and momentum transfer within a microgravity, vortex separator

Ellis, Michael Clay 15 May 2009 (has links)
Liquid and gas do not separate naturally in microgravity, presenting a problem for twophase space systems. Increased integration of multiphase systems requires a separation method adaptable to a variety of systems. Researchers at Texas A&M University (TAMU) have developed a microgravity vortex separator (MVS) capable of handling both a wide range of inlet conditions and changes in these conditions. To optimize the MVS design, the effects of nozzle area, separator geometry, and inlet flow rate must be understood. Computational fluid dynamics (CFD), in the form of Adapco’s Star-CD, is used, along with laboratory testing, to accomplish this goal. Furthermore, as analysis aids for the laboratory data and CFD results, relationships for radial pressure, bubble transit time, and momentum transfer were developed. Ground testing data showed a linear relationship between rotational speed and inlet flow rate. The CFD results compared well with the ground data and indicated that the majority of the rotational flow travels at nearly the same rotational speed. Examination of the tangential velocity profile also showed that a reduction of nozzle outlet area resulted in increased tangential velocities. Using dimensional analysis, a relationship between separator radius, inlet momentum rate, fluid properties, and rotational speed was found. Applying this relationship to the ground data and CFD results showed a strong correlation between the two dimensionless groups. Linear regression provided an equation linking rotational speed to the separator parameters. This equation was tested against the ground data and shown to predict average rotational speed well for all separator models. These results were used to calculate the radial and axial transit times of gas bubbles within the separation volume. Radial transit time was found to decrease more rapidly than axial transit time as gas volume increased, indicating axial and radial transit times are closest in value for the all liquid case and increasing gas core diameter improves the operational characteristics of the separator. From a design standpoint, the all liquid case provides a minimum flow rate for successful phase separation. Maximum flow rate depends on the pressure resources of the system.
6

Structural Analysis of Lamella Separator by the Finite Element Method

Wu, Chien-peng 10 August 2008 (has links)
In the past ten years, various sewage treatment technologies have got extensive and profound studying in the field of water pollution control in Taiwan. In each unit apparatus of the sewage disposal system, a lamella separator as the sewage treatment facility, is an important link in the structure, has irreplaceable functions. This research investigated the lamella separator structure by means of the static analysis, add factors of earthquake, and typhoon. To achieve the purpose, the researcher used the computer-aided design software Solidworks to set up this structure model. After that, he used finite element analysis software, ANSYS, to analyze the structure. This research simulated in three situations. In static, earthquake, and typhoon analysis, the researcher found the stress of the original modal is over the yielding stress of materials. So, the researcher modified the support of a model to reduce the stress. Generally, the researcher hoped that this study could provide helpful references for designers¡¦ relevant studies on lamella separator structure in the future.
7

STUDYING THE MAGNETIC SEPARATION OF OXYGEN CARRIER IN COAL DIRECT CHEMICAL LOOPING

Bagheri, Amin 01 August 2014 (has links)
Amin Bagheri, for the Master of Science degree in MECHANICAL ENGINEERING AND ENERGY PROCESSES, presented on June 23, 2014, at Southern Illinois University Carbondale TITLE: STUDYING THE MAGNETIC SEPARATION OF OXYGEN CARRIER IN COAL DIRECT CHEMICAL LOOPING MAJOR PROFESSOR: Dr. Tomasz S. Wiltowski Magnetic separation of oxygen carrier from coal after combustion by-products was studied. Samples were prepared using iron metal, hematite and magnetite mixed with quartz in three different concentrations. A variable speed and magnetic field intensity separator unit was designed and constructed to prove the concept of magnetic separation. The unit went through trial and error steps to improve overall functionality and efficiency including belt material selection, electromagnet selection, feeder and collector buckets, drive drum and idler manufacturing. Prepared samples were tested in different velocities and magnetic field intensities.
8

A Characterization of a Dual Chambered, Two Phase Separator

Klein, Casey 2009 December 1900 (has links)
A new two phase separator for use in space applications has been invented. It is a vortex separator designed to accommodate gas driven two phase flows of gas and liquid. The work presented here is a first of a kind study of this newly invented separator and is meant to determine the minimum inlet gas flow rate necessary for a stable vortex inside the separator for different separator geometries. A dimensional scaling analysis was done to predict this minimum inlet gas flow rate. Experiments were performed on the ground and in conjunction with NASA using their microgravity simulating plane to determine this minimum inlet gas flow rate. The results of the experiments and scaling analysis are compared. The new design consists of two chambers, a vortex generator and a separation chamber, meant to divide the functions of vortex creation and phase separation. The two phase flow is injected tangentially into the vortex generator causing the inlet linear momentum to be transformed into azimuthal momentum. The two phase mixture in the vortex generator then moves into the separation chamber where the two phases separate due to the density difference between the phases. The dimensional scaling analysis used the Weber number to predict the minimum rotational velocity of the spinning flow in the separation chamber during a stable vortex. This rotational velocity was related to the inlet gas flow rate by the inlet momentum rate. The scaling used the dimensions of each separator tested to predict the minimum inlet gas flow rate needed for a stable vortex. In all, twelve separators were tested, eleven on the ground and one on the plane. The ground testing was a parametric study varying the sizing of the separator components. The flight experiments kept the separator geometry constant and varied the gravitational field in which the separator operated. In general, the minimum inlet gas flow rate increased with the ratio of separation chamber diameter to vortex generator diameter. This same trend was consistent with the dimensional scaling analysis. Also, the inlet flow rate increases with gravitational acceleration.
9

Analysis and Development of a Decanter Centrifuge: Power consumption analysis, development of a composite bowl, and feed accelerator analysis

Bell, George Ross Arana January 2013 (has links)
This project was concerned with the analysis and development of a decanter centrifuge. The aim of the project was to increase the understanding of the operation of the machine, and identify and implement methods of improving the performance. A comprehensive breakdown of the power consumption of a GTech-Bellmor 1456 Centrifuge Decanter was completed. There are four components of the power consumption in a decanter centrifuge: friction during product transport, viscous and kinetic losses during feed acceleration, inefficiencies in power transmission components, and aerodynamic losses, known as windage. A mathematical model was developed to predict the power, torque, and axial force required by product transport. A relationship for the power consumed during feed acceleration was derived from first principles. The power transmission losses are comprised of inefficiencies in the motors, belt drives, gearbox, bearings, and seals; each of these was quantified. The windage has two components: the surface drag on the bowl as it rotates in an annular space and the pressure drag on external protrusions. The windage was predicted empirically and computationally. Methods that were identified for improving the decanter centrifuge were: reduce the mass of bowl and scroll, improve wear resistance, reduce the coefficient of friction of the bowl wall and scroll faces, optimise scroll geometry, redesign the feed accelerator to increase acceleration efficiency, implement control of the bowl speed, differential speed, and pool depth, and recess the bolt heads on the bowl and cover the third phase ports. An analysis of several worn centrifuges revealed that the majority of the wear occurs on the scroll, bowl wall, accelerator, and solids discharge ports. An experiment was developed to recreate the wear conditions inside a centrifuge. A high pressure abrasive film was forced between materials moving relative to each other. Similar results were observed for acetel, UHMWPE, and 316 stainless steel when using a pin-on-disk wear test rig. A new composite bowl was developed for two main reasons, weight reduction, and improved wear and friction characteristics. The full design process was applied to the bowl and several concepts were generated for a new scroll. The design of the bowl included conceptual design, material selection, material testing, constructing scale models, and the manufacture of a full-size bowl for a GTech-Bellmor 1456 Centrifuge Decanter. The potential for using composite materials in decanter centrifuges was demonstrated. The manufacturing method developed during this project was novel and produced parts suitable for use in high-speed rotating machinery. The feed accelerator analysis consisted of three components: theoretical, experimental, and computational analysis. Three feed acceleration mechanisms were identified: viscous dissipation, impulse force, and mass flow induced velocity. An experimental method was developed to examine decanter centrifuge feed accelerator designs. The method allowed for the measurement of efficiency and high-speed photography of the flow between the accelerator and the rotating pool. The order of best to worst performing of the six tested designs was Modified Disk, Disk, Plate, Conical, Drum, and Esbjerg. The feed accelerator was modelled using ANSYS-CFX 14.5 and compared to the experimental results. There was excellent agreement between the flow in the annular space observed using high-speed photography and the paths predicted using the computational model. A parametric study of the Drum and Disk feed accelerator designs was undertaken using the computational model. It was found that increasing the surface area of the port faces of the Drum accelerator and increasing the discharge angle and discharge radius for the Disk accelerator improved the performance.
10

Oljeavskiljare för biltvätt : Från idé till prototyp

Nahid, Mustafa Hammodi January 2015 (has links)
This thesis describes the development of a device called "Oil Separator" which is used for washing vehicles and particularly car washing. The device developed for Mr. Car Bilvård AB in Uppsala, the company's work involves passenger transport and courier services. The company needs an external device that meets the environmental standards to wash their own cars in the premises without the need to modify or reconstruct on the premises ground as the premises is on a leased contract. Work began with a preliminary study on the literatures that describes both the function and structure of designing the device. A few interviews with other car wash companies had been implemented, and some measurements. After collection of the necessary information the specifications of customer requirement was presented . With these requirements a few concepts was generated and weighed using the Pugh matrix for concepts selection for further development. The final concept was further developed and a design has been presented. A design of the washing place was taken up also which does not require any change in the premises by putting it on the ground. A functional smaller prototype of the oil separator was developed and tested.

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