Spiral Wound Gasket Compressibility and Pressure Ratings

2013 ◽  
Author(s):  
John McCarthy ◽  
A. Fitzgerald (Jerry) Waterland ◽  
Dan Reid
Keyword(s):  
Low Pressure ◽  
Pressure Application ◽  
Industry Practice ◽  
Proper Design ◽  
Design Characteristics ◽  
Selection Of ◽  
Spiral Wound

The industry practice of using pressure rating nomenclature to describe spiral wound gasket compressibility can contribute to some level of confusion regarding the proper design and selection of these gaskets. This situation can result in a misconception that a more easily compressed “soft” gasket (for example, “0–999 psi” rating) cannot be used in a higher pressure application. This is not necessarily true, and in many cases a softer (less dense) gasket construction can actually be beneficial in both high and low pressure applications. This article addresses both the terminology used to describe spiral wound gasket compressibility and the design characteristics of these gaskets in an effort to improve the understanding of this subject.

scholarly journals Topographical and Biomechanical Guidance of Electrospun Fibers for Biomedical Applications

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2896
Author(s):  
Sara Ferraris ◽  
Silvia Spriano ◽  
Alessandro Calogero Scalia ◽  
Andrea Cochis ◽  
Lia Rimondini ◽  
...  
Keyword(s):  
Surface Modification ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Electrospun Fibers ◽  
Natural Polymers ◽  
Polymeric Fibers ◽  
Biological Phenomena ◽  
Proper Design ◽  
Synthetic And Natural Polymers ◽  
Selection Of

Electrospinning is gaining increasing interest in the biomedical field as an eco-friendly and economic technique for production of random and oriented polymeric fibers. The aim of this review was to give an overview of electrospinning potentialities in the production of fibers for biomedical applications with a focus on the possibility to combine biomechanical and topographical stimuli. In fact, selection of the polymer and the eventual surface modification of the fibers allow selection of the proper chemical/biological signal to be administered to the cells. Moreover, a proper design of fiber orientation, dimension, and topography can give the opportunity to drive cell growth also from a spatial standpoint. At this purpose, the review contains a first introduction on potentialities of electrospinning for the obtainment of random and oriented fibers both with synthetic and natural polymers. The biological phenomena which can be guided and promoted by fibers composition and topography are in depth investigated and discussed in the second section of the paper. Finally, the recent strategies developed in the scientific community for the realization of electrospun fibers and for their surface modification for biomedical application are presented and discussed in the last section.

Volume reduction of produced water generated from natural gas production process using membrane technology

2000 ◽  
Vol 41 (10-11) ◽  
pp. 117-123 ◽  
Author(s):  
C. Visvanathan ◽  
P. Svenstrup ◽  
P. Ariyamethee
Keyword(s):  
Natural Gas ◽  
Produced Water ◽  
Hollow Fibre ◽  
Gas Production ◽  
Oil And Grease ◽  
Natural Gas Production ◽  
Pre Treatment ◽  
Selection Of ◽  
Spiral Wound

This paper presents a case study of a natural gas production site covering various technical issues related to selection of an appropriate Reverse Osmosis (RO) system. The long-term field experience indicates the necessity of the selection of appropriate pretreatment systems for fouling-free RO operational conditions. The produced water has a variety of impurities such as oil and grease, process chemicals used for corrosion and scaling control, and dehydration of natural gas, etc. This situation leads to a complicated and extremely difficult task for a membrane specialist to design RO systems, especially the pre-treatment section. Here as part of the pretreatment selection, two types of UF membrane modules viz. spiral wound and hollow fibre, with MWCO of 8000 and 50,000 Dalton respectively, were tested in parallel with NF membranes of the spiral wound type with MWCO 200 Dalton. The UF permeate is used as feed for RO compatibility testing. Both configurations of UF failed to be compatible, due to irreversible fouling of the RO membrane. The NF membrane, however, showed interesting results, due to membrane stability in terms of cleaning and fouling. The NF plant with 50% capacity gave a recovery of 75% and the RO plant gave a recovery of 60% versus the expected 92–95%. The long-term tests have indicated that the reminder of the membranes could be installed to achieve full capacity of the plant. This study also demonstrates the importance of selection of proper pre-treatment set-up for the RO system design.

Functionalization of liquid metal nanoparticles via the RAFT process

2021 ◽  
Author(s):  
Bo Fan ◽  
Jing Wan ◽  
Yiyi Liu ◽  
Wendy Wenjun Tian ◽  
San H. Thang
Keyword(s):  
Liquid Metal ◽  
Metal Nanoparticles ◽  
Grafted Polymers ◽  
Proper Design ◽  
Selection Of

The proper design and selection of RAFT agents allow the preparation of eutectic gallium–indium (EGaIn) based liquid metal nanoparticles with grafted polymers.

scholarly journals Effect on hand kinematics when using assistive devices during activities of daily living

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7806
Author(s):  
Alba Roda-Sales ◽  
Margarita Vergara ◽  
Joaquín L. Sancho-Bru ◽  
Verónica Gracia-Ibáñez ◽  
Néstor J. Jarque-Bou
Keyword(s):  
Activities Of Daily Living ◽  
Daily Living ◽  
Peak Velocity ◽  
Assistive Devices ◽  
Joint Angles ◽  
Kinematic Parameters ◽  
Hand Kinematics ◽  
Instrumented Glove ◽  
Design Characteristics ◽  
Selection Of

Assistive devices (ADs) are products intended to overcome the difficulties produced by the reduction in mobility and grip strength entailed by ageing and different pathologies. Nevertheless, there is little information about the effect that the use of these devices produces on hand kinematics. Thus, the aim of this work is to quantify this effect through the comparison of kinematic parameters (mean posture, ROM, median velocity and peak velocity) while performing activities of daily living (ADL) using normal products and ADs. Twelve healthy right-handed subjects performed 11 ADL with normal products and with 17 ADs wearing an instrumented glove on their right hand, 16 joint angles being recorded. ADs significantly affected hand kinematics, although the joints affected differed according to the AD. Furthermore, some pattern effects were identified depending on the characteristics of the handle of the ADs, namely, handle thickening, addition of a handle to products that initially did not have one, extension of existing handles or addition of handles to apply higher torques. An overview of the effects of these design characteristics on hand kinematics is presented as a basis for the selection of the most suitable AD depending on the patient’s impairments.

scholarly journals Effects of Turbine Design on Particulate Erosion of Turbine Airfoils

1991 ◽  
Author(s):  
J. H. Wagner ◽  
B. V. Johnson ◽  
D. W. Geiling
Keyword(s):  
Gas Turbines ◽  
Combustion Process ◽  
Particle Diameter ◽  
Surface Erosion ◽  
Erosion Rates ◽  
Trajectory Calculations ◽  
Design Characteristics ◽  
Turbine Airfoils ◽  
Turbine Design ◽  
Selection Of

An analytic study was conducted to determine the effects of turbine design, airfoil shape and material on particulate erosion of turbine airfoils in coal-fueled, direct-fired gas turbines used for electric power generation. First-stage, mean-line airfoil sections were designed for 80 MW output turbines with 3 and 4 stages. Two-dimensional particle trajectory calculations and erosion rate analyses were performed for a range of particle diameters and densities and for ductile and ceramic airfoil materials. Results indicate that the surface erosion rates can vary by a factor of 5 and that erosion on rotating blades is not well correlated with particle diameter. The results quantify the cause/effect turbine design relationships expected and assist in the selection of turbine design characteristics for use downstream of a coal-fueled combustion process.

scholarly journals Toward Incorporation of Membrane Properties Non-Uniformity in Spiral Wound Module Performance Simulators—Effect of Non-Uniform Permeability on Fouling Layer Evolution

Fluids ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 127 ◽  
Author(s):  
Margaritis Kostoglou ◽  
Anastasios Karabelas
Keyword(s):  
Experimental Studies ◽  
Membrane Properties ◽  
Design And Optimization ◽  
Systematic Assessment ◽  
Simulation Tools ◽  
Flow Pressure ◽  
Module Performance ◽  
Grid Level ◽  
Selection Of ◽  
Spiral Wound

A performance simulator of spiral wound membrane (SWM) modules used for desalination is a valuable tool for process design and optimization. The existing state-of-the-art mesoscale simulation tools account for the spatial non-uniformities created by the operation itself (flow, pressure, and concentration distributions) but they assume uniform membrane properties. However, experimental studies reveal that membrane properties are by no means uniform. Therefore, the need arises to account for this non-uniformity in simulation tools thus enabling a systematic assessment of its impact, among other benefits; a first step toward this goal is presented herein. In particular, the issue of an organic fouling layer growing on a membrane with non-uniform permeability is analyzed. Several mathematical treatments of the problem are discussed and indicative results are presented. The concept of fouling layer thickness probability density function is suggested as a means to introduce sub-grid level calculations in existing simulation tools. The analysis leads to the selection of an appropriate methodology to incorporate this effect in the dynamic simulation of fouling layer evolution at the membrane-sheet scale.

Method to determine the power efficiency of UV disinfection plants and its application to low pressure plants for drinking water

2016 ◽  
Vol 17 (4) ◽  
pp. 947-957 ◽  
Author(s):  
Alois W. Schmalwieser ◽  
Georg Hirschmann ◽  
Alexander Cabaj ◽  
Regina Sommer
Keyword(s):  
Drinking Water ◽  
Electric Power ◽  
Power Efficiency ◽  
Electrical Power ◽  
Low Pressure ◽  
Uv Disinfection ◽  
Plant Type ◽  
Uv Irradiance ◽  
Flow Through ◽  
Selection Of

In this paper we present a method to determine the power efficiency of ultraviolet (UV) disinfection plants and apply this to low pressure plants for drinking water. In UV disinfection plants the water flow is regulated to ensure that microorganisms receive the necessary fluence for inactivation while passing through. The flow depends on the UV transmission (UVT) of the water. The lower the UVT of the water is, the less water may flow through the plant. UV irradiance is produced by lamps that consume, together with other components, electrical power and entail running costs. The power efficiency – electrical power versus disinfected volume – of a plant has therefore an important impact. Applying this method to different UV plants that are on the market shows that electric power of at least 5.3 Wh is necessary to disinfect 1 m3 of water possessing a UVT of 80% (100 mm), 8 Wh at 50% and 22 Wh at 10%. Further we found that ineffective design or a wrong selection of a plant may enhance these values by a factor of up to 7. This method enables not only the calculation of the power efficiency but also the decision for a certain plant type.

scholarly journals Practical Experience with the Methodology of Prediction of Corrosion-Fatigue Failures of Steam Turbine Rotating Blades

2021 ◽  
Vol 349 ◽  
pp. 04015
Author(s):  
Josef Kasl ◽  
Jan Lazar ◽  
Miroslava Matějová
Keyword(s):  
Corrosion Fatigue ◽  
Low Pressure ◽  
Practical Experience ◽  
Cyclic Stress ◽  
Steam Turbines ◽  
Rotating Blades ◽  
Power Stations ◽  
Local Stresses ◽  
Corrosion Pits ◽  
Selection Of

Corrosion fatigue fractures initiating from corrosion pits are one of the most serious problem during service of rotating blades of the low-pressure parts of steam turbines. A methodology for fatigue failure prediction, originally based on the knowledge obtained by EPRI (Electric Power Research Institute), using corrosion pits parameters assessment and local stresses calculation was adapted to the conditions of ČEZ a.s. power stations. This contribution deals with the evaluation of the corrosion state of blades of three low pressure rotors after long service. Measurement was done in power stations equipped with turbines of power 200 MW and 110 MW respectively. Possibilities and uncertainties (influence of filling of pits with oxides, cyclic stress calculations, and the selection of the geometric factor Y) and their elimination are discussed.

scholarly journals INFLUENCE OF RIBBING ON THE STRESS-STRAIN STATE OF A FLAT ROUND TANK BOTTOM

2021 ◽  
Vol 112 ◽  
pp. 77-80
Author(s):  
А.K. Baibulov ◽  
◽  
N.V. Ivanitskaya ◽  
Keyword(s):  
Numerical Simulation ◽  
Strain State ◽  
Low Pressure ◽  
Correct Selection ◽  
Stress Strain ◽  
Stress Strain State ◽  
Head Surface ◽  
Tank Bottom ◽  
Rib Arrangement ◽  
Selection Of

Options with radial and longitudinal-transverse rib arrangement were considered. The research was carried out by numerical simulation in the ANSYS program. The values of stresses and deformations in the tank bottom were obtained depending on the number and location of stiffeners on it. It is established that the main load is perceived by the Central part of the ribs. Therefore, due to the correct selection of stiffeners, it is possible to reduce the thickness of the head plate. To equalize the stresses on the head surface, the number of edges should be at least six, and the radial placement of the edges is more preferable. With the same deformations, in this case, the stresses in the head are somewhat less. The results obtained make it possible to increase the strength of the flat head and use it in tanks intended for storing liquid and gaseous substances under low pressure.

Sign in / Sign up

Export Citation Format

Share Document