Use of High-Pressure Waterjets in Utility Industry Applications

2009 ◽  
pp. 597-597-19
Author(s):  
FA Huszarik ◽  
JM Reichman ◽  
JB Cheung
Keyword(s):  
High Pressure ◽  
Utility Industry ◽  
Industry Applications

Gas Turbines for Coal-Fired Turbocharged PFBC Boiler Power Plants

1984 ◽  
Author(s):  
Richard Wenglarz ◽  
Steven Drenker
Keyword(s):  
High Pressure ◽  
Gas Turbines ◽  
Power Plants ◽  
Modular Construction ◽  
Fluidized Bed Combustion ◽  
Gas Temperature ◽  
Utility Industry ◽  
Advantages And Disadvantages ◽  
Construction Methods ◽  
Standard Gas

A coal-fired turbocharged boiler using fluidized bed combustion at high pressure would be more compact than a pulverized coal fired boiler. The smaller boiler size could permit the utility industry to adopt efficient modular construction methods now widely used in other industries. A commercial turbocharger of the capacity needed to run a 250 MWe power plant doe not exist; commercial gas turbines of the correct capacity exist, but they are not matched to this cycle’s gas temperature of less than 538°C (1000°F). In order to avoid impeding the development of the technology, it will probably be desirable to use existing machines to the maximum extent possible. This paper explores the advantages and disadvantages of applying either standard gas turbines or modified standard gas turbines to the turbocharged boiler.

Aerodynamic Simulation of a High-Pressure Centrifugal Fan for Process Industries

2013 ◽  
Author(s):  
Alessandro Corsini ◽  
Giovanni Delibra ◽  
Franco Rispoli ◽  
Anthony G. Sheard ◽  
Paolo Venturini
Keyword(s):  
High Pressure ◽  
Flow Field ◽  
Incompressible Flow ◽  
Stokes Equations ◽  
Process Industry ◽  
Surface Erosion ◽  
Centrifugal Fan ◽  
Industry Applications ◽  
Critical Regions ◽  
Aerodynamic Investigation

Large centrifugal fans in cement factories operate in an aggressive environment, as the cement particles dispersed in the flow are responsible for strong blade surface erosion that leads to performance degradation. This paper reports on the simulation of the flow field in a large centrifugal fan designed for process industry applications. The aerodynamic investigation, at a preliminary level, highlights the critical regions inside the device and suggests possible modification to increase its duty life. This paper reports on the simulation of the flow field in a large centrifugal fan designed for process industry applications. The aerodynamic investigation, at a preliminary level, serves the aim of highlighting the critical regions inside the device and suggest possible modification to increase its duty life. In the paper we show the results of numerical computations carried out with the finite volume open-source code OpenFOAM using Multiple Reference Frame methodology. Reynolds Averaged Navier-Stokes equations for incompressible flow were solved with standard eddy-viscosity k-ε model in order to explore the aerodynamic behaviour of the fan in near-design operations. The incompressible flow hypothesis was adopted even if locally Mach number can exceed 0.5. In fact in this case the pressure-rise does not lead to a variation of the density able to affect the velocity field divergence. Given the high performance of the investigated impeller, the present work has a twofold objective. First, we seek to define an accurate numerical methodology to investigate high-pressure radial fans. Second, we provide detailed analysis of the inlet ring-impeller-volute assembly inner workings under realistic distorted inflow conditions. The results provide the evolution of the pressure field in order to validate the accuracy of the simulation in reproducing the motion inside the fan that was fundamental for credible particle dispersion reproduction. We then investigate the three-dimensional flow field through the impeller in order to provide details about the secondary flow structures that develop within the blade vanes.

Advanced NDE Techniques and Their Deployment on High Pressure Equipment

2012 ◽  
Author(s):  
Jeffrey P. Milligan ◽  
Daniel T. Peters ◽  
Jason K. Van Velsor
Keyword(s):  
High Pressure ◽  
Asset Management ◽  
Small Diameter ◽  
Guided Wave ◽  
Thick Section ◽  
Ultrasonic Guided Wave ◽  
Industry Applications ◽  
Inspection Data ◽  
Surface Examination ◽  
High Pressure Equipment

Many advances in Non-Destructive Examination (NDE) have occurred in recent years. Some of these are becoming common in typical industry applications and are slowly migrating their way into niche industries, such as high-pressure applications. These advanced NDE techniques include the use of Linear Phased Array (LPA) ultrasonic examination for volumetric examination and Eddy Current Array (ECA) technology for surface examination. Advancements in ultrasonic Guided Wave Testing (GWT) also show promise for the examination of long tubes, such as in tubular low density polyethylene (LDPE) reactors. Effective deployment and delivery of these advanced techniques is critical to the collection and analysis of the inspection data. Common challenges found in high-pressure equipment include access issues such as small diameter deep bores, large and thick section components, weld overlays and examination of thick section welds, complex geometries, and small crack sizes required for detection due to materials and design. Applying these modern techniques in new designs and updating of in-service inspection plans for this high-pressure equipment can lead to a more accurate assessment of the equipment’s fitness for continued service, reduced maintenance costs, proper asset management of key capital equipment, and reduced turn-around time.

High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

1991 ◽  
Vol 49 ◽  
pp. 64-65
Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Low Voltage ◽  
Culture Media ◽  
Cell Structure ◽  
Freeze Substitution ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Culture Media ◽  
Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

Prolonged Fixation Studies For Spaceflight

1973 ◽  
Vol 31 ◽  
pp. 332-333
Author(s):  
Robert Corbett ◽  
Delbert E. Philpott ◽  
Sam Black
Keyword(s):  
High Pressure ◽  
Living Systems ◽  
Prolonged Storage ◽  
Time Intervals ◽  
Early Signs ◽  
Large Numbers

Observation of subtle or early signs of change in spaceflight induced alterations on living systems require precise methods of sampling. In-flight analysis would be preferable but constraints of time, equipment, personnel and cost dictate the necessity for prolonged storage before retrieval. Because of this, various tissues have been stored in fixatives and combinations of fixatives and observed at various time intervals. High pressure and the effect of buffer alone have also been tried.Of the various tissues embedded, muscle, cartilage and liver, liver has been the most extensively studied because it contains large numbers of organelles common to all tissues (Fig. 1).

Cryosectioning plant roots prepared by high-pressure freezing

1987 ◽  
Vol 45 ◽  
pp. 662-663
Author(s):  
R.E. Crang ◽  
M. Mueller ◽  
K. Zierold
Keyword(s):  
High Pressure ◽  
Cell Walls ◽  
Plant Tissues ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Vitreous State ◽  
Radial Depth ◽  
Irregular Topography ◽  
Considerable Depth ◽  
Conventional Freezing

Obtaining frozen-hydrated sections of plant tissues for electron microscopy and microanalysis has been considered difficult, if not impossible, due primarily to the considerable depth of effective freezing in the tissues which would be required. The greatest depth of vitreous freezing is generally considered to be only 15-20 μm in animal specimens. Plant cells are often much larger in diameter and, if several cells are required to be intact, ice crystal damage can be expected to be so severe as to prevent successful cryoultramicrotomy. The very nature of cell walls, intercellular air spaces, irregular topography, and large vacuoles often make it impractical to use immersion, metal-mirror, or jet freezing techniques for botanical material.However, it has been proposed that high-pressure freezing (HPF) may offer an alternative to the more conventional freezing techniques, inasmuch as non-cryoprotected specimens may be frozen in a vitreous, or near-vitreous state, to a radial depth of at least 0.5 mm.

High-pressure freezing and freeze substitution of plant tissue

1992 ◽  
Vol 50 (1) ◽  
pp. 748-749
Author(s):  
William P. Sharp ◽  
Robert W. Roberson
Keyword(s):  
High Pressure ◽  
Cell Structure ◽  
Leaf Tissue ◽  
Freeze Substitution ◽  
Crystal Formation ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Components ◽  
Cold Metal ◽  
Brome Grass

The aim of ultrastructural investigation is to analyze cell architecture and relate a functional role(s) to cell components. It is known that aqueous chemical fixation requires seconds to minutes to penetrate and stabilize cell structure which may result in structural artifacts. The use of ultralow temperatures to fix and prepare specimens, however, leads to a much improved preservation of the cell’s living state. A critical limitation of conventional cryofixation methods (i.e., propane-jet freezing, cold-metal slamming, plunge-freezing) is that only a 10 to 40 μm thick surface layer of cells can be frozen without distorting ice crystal formation. This problem can be allayed by freezing samples under about 2100 bar of hydrostatic pressure which suppresses the formation of ice nuclei and their rate of growth. Thus, 0.6 mm thick samples with a total volume of 1 mm3 can be frozen without ice crystal damage. The purpose of this study is to describe the cellular details and identify potential artifacts in root tissue of barley (Hordeum vulgari L.) and leaf tissue of brome grass (Bromus mollis L.) fixed and prepared by high-pressure freezing (HPF) and freeze substitution (FS) techniques.

Microstructural Study of Diamond Deformed Under High Pressure and Temperature

1985 ◽  
Vol 43 ◽  
pp. 230-231
Author(s):  
E. F. Koch
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Lattice Structure ◽  
Diamond Particle ◽  
Polycrystalline Diamond ◽  
Sintering Process ◽  
Ion Milling ◽  
Sintered Compact ◽  
Transmission Electron ◽  
High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

Formation of defects in implanted hipox-structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1406-1407
Author(s):  
Peter Pegler ◽  
N. David Theodore ◽  
Ming Pan
Keyword(s):  
High Pressure ◽  
Cross Section ◽  
Semiconductor Devices ◽  
Silicon Substrates ◽  
Processing Conditions ◽  
Pressure Oxidation ◽  
Deep Trench ◽  
Local Oxidation ◽  
Trench Isolation ◽  
And Behavior

High-pressure oxidation of silicon (HIPOX) is one of various techniques used for electrical-isolation of semiconductor-devices on silicon substrates. Other techniques have included local-oxidation of silicon (LOCOS), poly-buffered LOCOS, deep-trench isolation and separation of silicon by implanted oxygen (SIMOX). Reliable use of HIPOX for device-isolation requires an understanding of the behavior of the materials and structures being used and their interactions under different processing conditions. The effect of HIPOX-related stresses in the structures is of interest because structuraldefects, if formed, could electrically degrade devices.This investigation was performed to study the origin and behavior of defects in recessed HIPOX (RHIPOX) structures. The structures were exposed to a boron implant. Samples consisted of (i) RHlPOX'ed strip exposed to a boron implant, (ii) recessed strip prior to HIPOX, but exposed to a boron implant, (iii) test-pad prior to HIPOX, (iv) HIPOX'ed region away from R-HIPOX edge. Cross-section TEM specimens were prepared in the <110> substrate-geometry.

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