Hydroblasting and Coating of Steel Structures

222 Pages·2004·5.407 MB·English

by  A. Momber

6 Coating of Steel Structures

Hydroblasting and Coating of Steel Structures

Hy d r o bI a st i ng
and Coating of
Steel Structures
Andreas W. Momber
Privatdozent, Department of Mining,
Metallurgy and Earth Sciences,
RWTH Aachen Germany
ELSEVIER
UK Elsevier Ltd, The Boulevard, Langford Lane, Kidlington, Oxford OX5
lGB, UK
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Copyright 0 2003 Elsevier Science Ltd.
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Cover illustration: Courtesy of Muhlhan Surface Protection International GmbH,
Hamburg, Germany
British Library Cataloguing in Publication Data
Momber, Andreas W., 1959-
Hydroblasting and coating of steel structures
1.Water jet cutting 2.Stee1, Structural - Cleaning
3.Building, Iron and steel - Cleaning
1.Title
620.1’06
ISBN 185617395X
Library of Congress Cataloging-in-PublicationD ata
Momber, Andreas W., 195 9 -
Hydroblasting and coating of steel structures / Andreas W. Momber
p. cm.
Includes bibliographical references and index.
ISBN 1-85617-395-X (hardcover)
1. Steel, Structural - Corrosion. 2. Corrosion and anti-corrosives.
I. Title.
TA467 .M545 2002
620.1’723 -dc2 1 2002040768
No responsibility is assumed by the Publisher for any injury andlor damage to
persons or property as a matter of products liability, negligence or otherwise, or
from any use or operation of any methods, products, instructions or ideas contained
in the material herein.
Published by
Elsevier Advanced Technology,
The Boulevard, Langford Lane, Kidlington, Oxford OX5 lGB, UK
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Printed and bound in Great Britain by Biddles Ltd, Guildford and King’s Lynn
Contents
List of Symbols and Abbreviations Used vii
1 Introduction
1.1 Definitions of surfaces and preparation methods
1.2 Importance of surface preparation processes
1.3 Subdivision of water jets
1.4 Industrial applications
2 Fundamentals of Hydroblasting 17
2.1 Properties and structure of high-speed water jets 18
2.2 Basic processes of water drop impact 24
2.3 Parameter influence on the coating removal 29
2.4 Models of coating removal processes 38
3 Hydroblasting Equipment 45
3. I High-pressure water jet machines 46
3.2 Pressure generator 47
3.3 High-pressure hoses and fittings 55
3.4 Hydroblasting tools 59
3.5 Nozzle carriers 63
3.6 Hydroblasting nozzles 66
3.7 Vacuuming and water treatment systems 73
4 Steel Surface Preparation by Hydroblasting 77
4.1 Efficiency of hydroblasting 78
4.2 Cost aspects 84
4.3 Problems of disposal 87
4.4 Safety features of hydroblasting 94
5 Surface Quality Aspects 113
5.1 Surface quality features 114
5.2 Adhesion strength 114
5.3 Flash rust 121
5.4 Non-visible contaminants - salt content 126
vi Contents
5.5 Embedded abrasive particles 133
5.6 Wettability of steel substrates 136
5.7 Roughness and profile of substrates 138
5.8 Aspects of substrate surface integrity 144
6 Hydroblasting Standards 149
6.1 Introduction 150
6.2 Initial conditions 151
6.3 Visual surface preparation definitions and cleaning degrees 152
6.4 Non-visible surface cleanliness definitions 154
6.5 Flash rusted surface definitions 155
6.6 Special advice 157
7 Alternative Developments in Hydroblasting 159
7.1 Pulsed liquid jets for surface preparation 160
7.2 Hydro-abrasive jets for surface preparation 169
7.3 High-speed ice jets for surface preparation 176
7.4 Water jethltrasonic device for surface preparation 181
References 183
Appendix 199
Index 203
~ ~
List of Symbols and
Abbreviations Used
model parameter
jet structure parameter
cleaned surface
cleaning rate
nozzle (orifice) cross section
plunger cross section
jet structure parameter
fatigue parameter
cleaning energy flux
speed of sound water
constant
speed of sound target
paint consumption
jet spreading coefficient
paint degradation rate
drop diameter
maximum drop diameter
Sauter diameter (water drop)
dry film thickness
hose diameter
jet diameter
nozzle (orifice) diameter
plunger diameter
threshold nozzle diameter
cleaning effectiveness
kinetic energy hydro-abrasive jet
cleaning efficiency
kinetic energy water jet
Young’s modulus
kinetic energy abrasive particle
specific energy
frequency pulsating liquid jet