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title: OilMist Lubrication : Practical Applications author: Bloch, Heinz P.; Shamim, Abdus publisher: The Fairmont Press isbn10 | asin: 0881732567 print isbn13: 9780881732566 ebook isbn13: 9780585120263 language: English subject Oil mist lubrication. publication date: 1998 lcc: TJ1073.6.B556 1998eb ddc: 621.8/9 subject: Oilmist lubrication. cover next page > Page iii Oil Mist Lubrication: Practical Applications Heinz P. Bloch. P.E. and Abdus Shamim,Ph.D. Published by THE FAIRMONT PRESS, INC. 700 Indian Trail Lilburn, GA 30047 < previous page page_iii next page > Page iv Library of Congress Cataloging-in-Publication Data Bloch, Heinz P., 1933 Oil mist lubrication: practical applications / Heinz P. Bloch and Abdus Shamim. p. cm. Includes bibliographical references and index. ISBN 0-88173-256-7 1. Oil mist lubrication. I. Shamim, Abdus, 1964-. II. Title. TJ1073.6.B556 1998 621.8'9--dc21 97-53166 CIP Oil mist lubrication: practical applications by Heinz P. Bloch andAbdus Shamim. © 1998 by The Fairmont Press, Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publisher. Published by The Fairmont Press, Inc. 700 Indian Trail Lilburn, GA 30247 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 ISBN 0-88173-256-7 FP ISBN 0-13-975210-2 PH While every effort is made to provide dependable information, the publisher, authors, and editors cannot be held responsible for anyerrors or omissions. Distributed by Prentice Hall PTR Prentice-Hall, Inc. A Simon & Schuster Company Upper Saddle River, NJ 07458 Prentice-Hall International (UK) Limited, London Prentice-Hall of Australia Pty. Limited, Sydney Prentice-Hall Canada Inc., Toronto Prentice-Hall Hispanoamericana, S.A., Mexico Prentice-Hall of India Private Limited, New Delhi Prentice-Hall of Japan, Inc., Tokyo Simon & Schuster Asia Pte. Ltd., Singapore Editora Prentice-Hall do Brasil, Ltda., Rio de Janeiro < previous page page_iv next page > Pagev To June and Rima < previous page page_v next page > Page vii CONTENTS Preface ix Part I Practical Applications 1 Chapter 1 The Impact of Oil-mist Lubrication 1 Chapter 2 Operating Principles and Systems Overview 9 Chapter 3 Lubricants for Oil-mist Systems 15 Chapter 4 Components of a Plant-Wide Oil-mist System 29 Chapter 5 Oil-mist Application and Venting 51 Chapter 6 Lubricant Collection 61 Chapter 7 Selecting the Application Fittings 71 Chapter 8 Rating Individual Machine Elements 81 Chapter 9 Electric Motor Lubrication 103 Chapter 10 Closed-Loop Oil-mist Installations 111 Chapter 11 Sparing and Redundancy Considerations 121 Chapter 12 Specifications for Oil-mist Systems 125 < previous page page_vii next page > Page viii Chapter 13 Field Implementation 131 Chapter 14 Shipping and Storing Oil-mist-Lubricated Equipment 143 Chapter 15 Economic Justification for Dry-Sump Oil-mist Lubrication 155 Part 2 Scientific Principles 165 Chapter 16 Overview of Scientific Principles 165 Chapter 17 Generation of Oil Mist 165 Chapter 18 Supply of Oil Mist to Application Points 181 Chapter 19 Reclassification of Oil Mist 195 Chapter 20 Deposition of Oil at the Point of Application and Stray Mist 205 Chapter 21 Tribological Performance of Oil-mistLubrication 217 Appendices ASample Specification for Oil-mist Lubrication Systems 237 BOil-mist System Troubleshooting Chart 249 CConversion Data 251 Glossary 262 References 267 Bibliography 271 Index 277 < previous page page_viii next page > Page ix PREFACE In a way, not much has changed since the First Edition of this text was released in 1987. It's surely as true as it was in 1987 that there is very little of substance on the face of the earth that someone hasn't already done, experienced, or even written about. Oh yes, there has been an "information explosion," but even an optimist will have to agree that it hasn't been a knowledge explosion, let alone a measurable increase in wisdom. That said, it would be presumptuous to claim an exception for the technical topic of oil-mist lubrication. Oil mist lubrication has been applied since the 1930's and what many an old-timer has known for years we had condensed into the 1987 text. Still, in the late 1980's, a significant step forward was initiated when Texas A&M University, in College Station, received a state grant to study the theory of oil mist lubrication. As the younger member of this co-author team (A.S.) started to work on the project in fulfillment of requirements towards M.S., and later Ph.D. degrees in mechanical engineering, it became evident to the recent Exxon retiree (HPB) that the First Edition of this text no longer represented a comprehensive write-up of current knowledge. So, the two of us teamed up and decided that the impressive findings that were documented at Texas A&M are certain to be of interest and value to a very wide maintenance- technical, and also academic audience. Here, then, is the result: A revised and thoroughly expanded Second Edition, which includes the key findings of these efforts and extends the pool of knowledge from the primarily practical to previously unknown theoretical aspects of oil-mist technology. We owe thanks to the same companies and individuals who were instrumental in making the original, 1987 edition possible: Alemite Division of Stewart-Warner (Charlotte, North Carolina), Lubrication Systems, Inc. (Houston, Texas), and C.A. Norgren Company (Littleton, Colorado). Their kind permission to make liberal use of, and to synthesize into book format, major portions of their copyrighted material are gratefully acknowledged, as are the diligent efforts of Alemite retiree Donald M. Bornarth inreviewing the initial manuscript. Very special thanks are reserved for Dr. Fred Kettleborough, whose guidance and direction as faculty advisor at Texas A&M was instrumental in channeling everyone's energies in the right direction. May the reader benefit from our efforts, and also from the generous input we received from others. HEINZ P. BLOCH, P.E. MONTGOMERY, TEXAS ABDUS SHAMIM, PH.D. CINCINNATI, OHIO JANUARY, 1998 < previous page page_ix next page > Page1 PART 1: PRACTICAL APPLICATIONS Chapter 1 The Impact of Oil-Mist Lubrication The application of centralized liquid lubrication to machines is not new.Conventional circulating, pump-driven liquid lubrication systems have been in successful use for decades. They were designed and implemented because they offered many advantages and did away with much of the "human" element of machinery lubrication. The time-consuming task of manual point-by-point lubrication was thus eliminated, as was the requirement for making all lubricationpoints accessible for maintenance. These liquid-oil circulating systems, while providing advantages, were nevertheless found to impose additional handicaps upon machine designs. They can be expensive, since pumps, filters, reservoirs, and piping are required. Machine assembly is more difficult, and the pump itself becomes an extra maintenance item. Moreover, the development of extremely high- speed grinders and spindles demonstrated that a liquid-oil environment can cause certain bearings to run hot. The added heat input often results in accelerated oxidation and a sharp decrease in the service life of the lubricant. It was then realized that the distribution of lubricant by conveying oil particles in compressed air overcomes many of the drawbacks of a circulating liquid system. No pump and no return piping is required. Using the energy of this compressed air stream allows the generation of a fine, dry, smoke-like fog of oil particles. This dry-oil fog can be conveyed over distances up to 150 m, or close to 500 ft, through piping or tubing. Keeping the flow velocity below 7 meters per second (roughly 22 feet per second) results in very little of the oil condensing in the piping or tubing. At the point of lubrication, an application fitting or reclassifier nozzle will either meter this dry fog or change it to a wet fog,which is applied directly to the machine element to be lubricated. For many years now, centralized oil-mist application has permitted the continuous lubrication of numerous machine elements, requiring only one common lubricator to be maintained per system. Oil mist has been used to lubricate bearings of all types, gears, chains, slides, ways, and other devices requiring a thin film of oil for lubrication. Soon after World War II, machine tool builders began to design oil-mist lubrication into their finest and costliest machines (Figure 1-1). Textile mills, steel mills, mine operators, paper and rubber factories (Figures 1-2 through 1-5) have applied it to web and processing equipment, conveyors, mobile equipment, shaker screens, vibrators, crushers, centrifuges, kilns, pulverizers, dryers, and a host of other equipment. The results have been excellent. In the highly conservative petrochemical industry, entire billion-dollar complexes have adapted oil mist to thousands of new and existing rolling element bearings in pumps and electric motors (Figures 1-6 and 1-7). Oil mist lubrication has also been used to lubricate railway rails and wheel flanges, resulting in up to 400% reduction in wheel flange wear [66]. < previous page page_1 next page > Page2 Figure 1-1. Since the late 1940s, sophisticated machine tools have been equipped with oil-mist lubrication(Source: C.A. Norgren Company.) These industrial users have established that oil mist has significant advantages over most other methods of lubrication. Continuous application of oil can be matched closely to actual bearing requirements. The low rate of lubricant application made possible with oil mist provides continuous lubrication without the necessity of designing a circulating system. This reduces the manufacturing and installation cost of many designs and improves housekeeping by reducing oil consumption, particularly where oil seal maintenance is a problem. Heat generation due to lubricant friction is reduced to a minimum in applications where a liquid oil sump is no longer maintained. We call this a pure mist, or dry sump oil mist application mode, to distinguish from wet sump applications where oil mist is used as a bearing housing purge. The pros and cons of the two application modes are dealt withlater. < previous page page_2 next page >