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الموضوع: cathodic protection

  1. #1
    عضو فى رابطة مهندسى الكهرباء العرب الصورة الرمزية مصطفى محمود الشعرواى
    تاريخ التسجيل
    Aug 2006
    الدولة
    egypt
    المشاركات
    96

    cathodic protection

    اليكم هذا الملف عن cathodic protection و لا اطلب منكم سوى الدعاء

  2. #31
    V.I.P Member الصورة الرمزية kareemradi
    تاريخ التسجيل
    Feb 2008
    الدولة
    iraq
    المشاركات
    118

    رد: cathodic protection

    The effect of protective coatings on galvanic
    corrosion for bolted components
    KS. Yeung
    Ford Motor Company, Ml, USA
    Abstract
    The increasing demands for better fuel-efficiency have led the automobile
    industry to use lightweight ****ls such as aluminum and magnesium in
    conjunction with conventional ****ls such as steel. Galvanic corrosion is the unfortunate result of this “mixed ****ls” usage. The automobile companies rely primarily on proving ground testing to evaluate the severity of corrosion. Such a procedure is costly and time consuming. The ******ive of this project is to explore the feasibility of using computer simulation to predict galvaniccorrosion in automobile environments. The BEASY code has been chosen for this project. There are two parts in the study. The first part is to validate BEASY and the second part is to perform the bolted component corrosion simulations This study shows that with as little as 2 mm of protective coatings, the peak corrosion rate can be reduced by as much as 70%. The BEASY code is a potentially useful tool to estimate the corrosion rate if an accurate representation of a current density and electrical potential relationship - the polarization curve -
    of the ****ls of interest can be experimentally determined.

  3. #32
    V.I.P Member الصورة الرمزية kareemradi
    تاريخ التسجيل
    Feb 2008
    الدولة
    iraq
    المشاركات
    118

    رد: cathodic protection

    Influence of Seawater Composition on
    Corrosion Prevention System Parameters
    V. G. DeGiorgi
    IMechanics of Materials Branch, Code 6382, Naval Research
    Laboratory, Washington, DC 20375, U.S.A.
    Abstract
    Cathodic protection systems, such as those designed for
    ships, u tilize material elec trot hemical properties t 0
    minimize corrosion damage. The extent of material
    interaction in the corrosion process is partially dependent
    on the resitivity of the surrounding medium. A medium
    with low resititvity, such as seawater, provides a greater
    degree of electrical connectivity than a medium of higher
    resistivity. In computational modeling studies seawater is
    typically represented as a uniform continuum with a single
    set of material properties. In reality, the resistivity of
    seawater varies with the amount of salt ******* and
    temperature. Salt ******* may vary for many reasons,
    including an influx of fresh water or evaporation. In this
    work variations in corrosion protection provided by an
    impressed current cathodic protection system under
    moderate variations in seawater resistivity are examined.

  4. #33
    V.I.P Member الصورة الرمزية kareemradi
    تاريخ التسجيل
    Feb 2008
    الدولة
    iraq
    المشاركات
    118

    رد: cathodic protection

    Characterization accuracy in modeling of
    corrosion systems
    V.G. DeGiorgP, A. Keeb, E.D. Thomas’

    “Mechanics of i’klaterials Branch, Naval Research
    Laboratory, Washington DC, USA
    bGeo-Centers 1 Inc., Ft. Washington, MD, USA
    ‘Corrosion Facility, Naval Research Laboratory, _
    Key West, FL, USA
    ABSTRACT
    Boundary element techniques are well suited for the solution of
    LaPlace’s equation in semi-infinite and infinite volumes. As in
    any computer modeling, issues must be addressed in the early
    stages of the analysis for the finished work to be an accurate
    evaluation of the system. The goal of the analysis must be clearly
    defined; preliminary and trend analyses often require less mesh
    refinement than detailed system evaluations. The work presented
    is a portion of a detailed evaluation of the impressed current
    cathodic protection system of an U S Navy CG class surface ship.
    Physical scale model experimental data was available for direct
    comparison with computational results

  5. #34
    V.I.P Member الصورة الرمزية kareemradi
    تاريخ التسجيل
    Feb 2008
    الدولة
    iraq
    المشاركات
    118

    رد: cathodic protection

    Predicting corrosion related electrical and
    magnetic fields using BEM
    Robert Adey, John Baynham
    Computational Mechanics BEASY Ltd, Ashurst Lodge, Ashurst, Southampton, Hampshire,
    SO40 7AA, UK Tel: +44 (2380) 293223 Fax: +44 (2380) 292853
    www.beasy.comr.adey@beasy.com
    Abstract
    Computer models have for some years been used to predict the performance of ICCP systems on ships and boats. The ******ive being to achieve optimum protection of the vessel from corrosion and to predict the associated fields/signatures However, in many cases these models have been based on simple dipole approximations. In this paper a new system is described which integrates the electric and magnetic models to
    provide a tool capable of accurately predicting the impact of any change in the ICCP system surface conditions or environmental conditions on the electric and magnetic signatures The model is based on the boundary element method which enables the exact geometry of the
    vessel to be described including anodes, reference electrodes, surface conditions and
    polarisation properties.

  6. #35
    V.I.P Member الصورة الرمزية kareemradi
    تاريخ التسجيل
    Feb 2008
    الدولة
    iraq
    المشاركات
    118

    رد: cathodic protection

    THE COMPREHENSIVE SOLUTION FOR ENGINEERS WHO
    NEED TO PREDICT ELECTRIC AND MAGNETIC SIGNATURES:
    P
    Vrediction of
    essel Condition
    General Cathodic
    Protection Modeller
    Design ICCP systems
    Optimise CP system operation
    Identify optimum anode locations
    Design ICCP control parameters
    Predict electric and magnetic signatures CRM Corrosion
    UEP Corrosion Electric and Magnetic Related
    Minimise signatures Related Electric Signatures
    Magnetic Field
    Use onboard data and/or signature to predict Field
    condition of the vessel
    Design Orientated
    Polarisation
    Modelling System
    Database
    Optimise ICCP System Design
    If you are responsible for the design, manufacture or
    deployment of defence equipment then you are aware of the
    need for minimum signature particularly electrical and
    magnetic signatures. BEASY can help with the electric (UEP)
    and magnetic (CRM) field prediction.
    PREDICTION OF ELECTRIC (UEP) AND MAGNETIC (CRM) FIELDS
    BEASY has been widely used to predict the performance of
    cathodic protection systems by modelling the coupled
    electric fields and electrochemistry for complete ships and
    other structures. The BEASY electric and magnetic field
    software provides, in one detailed model, an
    integrated approach to predicting the
    performance of the ICCP system, the
    corrosion related electric field and magnetic
    field.
    SIGNATURE OPTIMISATION
    BEASY provides the tools necessary to
    optimise the cathodic protection system to
    ensure the final design meets the
    customer’s criteria. Anode location, anode
    currents, position of reference electrodes,
    paints and coatings and structure geometry
    can be varied to achieve an optimum design.
    COMPUTATIONAL MECHANICS BEASY
    COMPUTATIONAL MECHANICS INC.
    A
    Ashurst Lodge, Ashurst,
    25 Bridge Street,
    Southampton, SO40 7AA, UK. .
    Billerica MA 01821, USA.
    Tel: 44 (0) 238 029 3223 Fax: (0) 238 029 2853
    Tel: 978 667 5841 Fax: 978 667 7582
    E-Mail: sales@beasy.com www.beasy.com E-Mail: sales@beasy.com www.beasy.com

  7. #36
    V.I.P Member الصورة الرمزية kareemradi
    تاريخ التسجيل
    Feb 2008
    الدولة
    iraq
    المشاركات
    118

    رد: cathodic protection

    Prediction of the Condition of a Structure
    Subject To Corrosion Based On Inverse

    Analysis
    E. Santana Diaz, R Adey, J Baynham
    Computational Mechanics BEASY, UK.
    Abstract
    Damages appear on a hull of a vessel during its lifetime. In many cases the exactposition of this damage are completely unknown. Its knowledge is important from mainly two points of view 1. Cathodic protection of the vessel. A corroded hull would be economically inefficient (current and fuel consumption) apart from being potentially dangerous since it is a hot point for crack corrosion 2. Signature of the vessel. A vessel can be detected from its surrounding

  8. #37
    V.I.P Member الصورة الرمزية kareemradi
    تاريخ التسجيل
    Feb 2008
    الدولة
    iraq
    المشاركات
    118

    رد: cathodic protection

    Cathodic Protection
    Introduction 1
    This is an update of a DTI publication first issued in 1981. The
    new version has been prepared by Eur Ing R. L. Kean of ARK
    Corrosion Services and Mr K. G. Davies, Corrosion Engineer,
    under contract from NPL for the Department of Trade and
    Industry.
    *******s page
    History 1
    The Principles of Cathodic Protection 1
    Sacrificial anodes 2
    Impressed current 2
    Advantages and Uses of Cathodic Protection 2
    Pipelines
    Storage tanks
    Steel pilings
    Reinforced concrete
    Ships
    Offshore structures
    Basic Requirements for Cathodic Protection 3
    Design Factors 4
    Monitoring and Maintenance 6
    Sources of advice 7
    Further Information 7

  9. #38
    V.I.P Member الصورة الرمزية kareemradi
    تاريخ التسجيل
    Feb 2008
    الدولة
    iraq
    المشاركات
    118

    رد: cathodic protection

    Optimization-Modeling Process
    Optimization problems are ubiquitous in the mathematical modeling of real world systems and cover a very broad range of applications. These applications arise in all branches of Economics, Finance, Chemistry, Materials Science, Astronomy, Physics, Structural and Molecular Biology, Engineering, Computer Science, and Medicine.
    Optimization modeling requires appropriate time. The general procedure that can be used in the process cycle of modeling is to: (1) describe the problem, (2) prescribe a solution, and (3) control the problem by assessing/updating the optimal solution continuously, while changing the parameters and structure of the problem. Clearly, there are always feedback loops among these general steps.
    Mathematical Formulation of the Problem:
    As soon as you detect a problem, think about and understand it in order to adequately describe the problem in writing. Develop a mathematical model or framework to re-present reality in order to devise/use an optimization solution algorithm. The problem formulation must be validated before it is offered a solution. A good mathematical formulation for optimization must be both inclusive (i.e., it includes what belongs to the problem) and exclusive (i.e., shaved-off what does not belong to the problem).


  10. #39
    V.I.P Member الصورة الرمزية kareemradi
    تاريخ التسجيل
    Feb 2008
    الدولة
    iraq
    المشاركات
    118

    رد: cathodic protection

    THE ELECTROCHEMISTRY OF CORROSION
    Edited by Gareth Hinds from the original work of J G N Thomas
    INTRODUCTION
    The surfaces of all ****ls (except for gold) in air are covered with oxide films. When such a ****l is immersed in an aqueous solution, the oxide film tends to dissolve. If the solution is acidic, the oxide film may dissolve completely leaving a bare ****l surface, which is said to be in the active state. In near-neutral solutions, the solubility of the oxide will be much lower than in acid solution and the extent of dissolution will tend to be smaller. The underlying ****l may then become exposed initially only at localised points where owing to somediscontinuity in the ****l, e.g. the presence of an inclusion or a grain boundary, the oxide film may be thinner or more prone to dissolution than elsewhere. If the near-neutral solution

  11. #40
    V.I.P Member الصورة الرمزية kareemradi
    تاريخ التسجيل
    Feb 2008
    الدولة
    iraq
    المشاركات
    118

    رد: cathodic protection

    CATHODIC PROTECTION P E FRANCIS
    *******S

    1 INTRODUCTION............................ ........................................ ........................................ 2
    2 PRINCIPLES OF CATHODIC PROTECTION.............................. ............................3
    3 METHODS OF APPLYING CATHODIC PROTECTION.............................. ..........5
    3.1 IMPRESSED CURRENT................................. ........................................ .................5
    3.2 SACRIFICIAL ANODES.................................. ........................................ ................6
    4 DESIGN ........................................ ........................................ ........................................ ....8
    4.1 PROTECTION POTENTIALS ........................................ ........................................ .8
    4.2 CURRENT DENSITY................................. ........................................ ......................8
    4.3 COATINGS ........................................ ........................................ ...............................9
    4.4 CALCAREOUS SCALES ........................................ ........................................ .........9
    4.5 CHOICE OF CATHODIC PROTECTION SYSTEM ........................................ ......9
    4.6 ANODE RESISTANCE ........................................ ........................................ ..........10
    4.7 DANGERS TO BE AVOIDED ........................................ .......................................1 2

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المواضيع المتشابهه

  1. CATHODIC PROTECTION
    بواسطة Eng.mohammed alqaissi في المنتدى قسم الموضوعات العامة
    مشاركات: 9
    آخر مشاركة: 02-08-15, 05:26 PM
  2. cathodic protection
    بواسطة مصطفى محمود الشعرواى في المنتدى قسم وقاية نظم القوى الكهربائية Power System Protection
    مشاركات: 79
    آخر مشاركة: 20-12-10, 06:43 PM
  3. cathodic protection
    بواسطة عبدالعزيزطمان في المنتدى قسم الخطوط الهوائيه لنقل وتوزيع الطاقه Over Head Transmission Lines
    مشاركات: 5
    آخر مشاركة: 09-09-09, 12:56 PM
  4. Cathodic Protection
    بواسطة ahmed fouad في المنتدى قسم الموضوعات العامة
    مشاركات: 0
    آخر مشاركة: 04-12-06, 06:35 PM

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