Marine Machinery 7 E Part 1 ppsx

Preface vil Acknowledgements ix 1 Main propulsion services and heat exchangers 1 2 Machinery service systems and equipment 40 3 Ship service systems 78 4 Valves and pipelines 112 5 Pumps

Marine Auxiliary Machinery

This page intentionally left blank

Marine Auxiliary Machinery

Seventh edition

H D McGeorge

C Eng, FIMarE, MRINA, MPhil

OXFORD AMSTERDAM BOSTON LONDON NEW YORK PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO

An imprint of Elsevier Science

Linacre House, Jordan Hill, Oxford OX2 8DP

225 Wild wood Avenue, Woburn, MA 01801-2041

First published 1952 Reprinted 1976,1979

Second edition 1955 Sixth edition 1983

Third edition 1963 Reprinted 1987

Fourth edition 1968 Seventh edition 1995

Reprinted 1971,1973 Paperback edition 1998

Fifth edition 1975 Reprinted 1999, 2000 (twice), 2002

© Copyright 1995, Elsevier Science Ltd All rights reserved

No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether

or not transiently or incidental! to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of

a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England WIT 4LP Applications for the copyright holder's written permission to reproduce any part of this publication should be addressed

tit the publishers

British Library Cataloguing in Publication Data

Marine Auxiliary Machinery - 7lh rev edn

I McGeorge, H David

0623.8

Library of Congress Cataloguing in Publication Data

McCeorge, H D.

Marine Auxiliary Machinery/H D McGeorge - 7th edn

Includes bibliographical references and index

1 Marine engines 2 Marine machinery I Title

Typeset by Vision Typesetting, Manchester

Printed and bound in Great Britain by MPG Books Ltd, Bodrnin, Cornwall

Preface vil Acknowledgements ix

1 Main propulsion services and heat exchangers 1

2 Machinery service systems and equipment 40

3 Ship service systems 78

4 Valves and pipelines 112

5 Pumps and pumping 139

6 Tanker and gas carrier cargo pumps and systems 176

12 Heating, ventilation and air conditioning 368

13 Deck machinery and cargo equipment 392

14 Fire protection 418

15 Safety and safety equipment 458

16 Control and instrumentation 480

Index 507

This page intentionally left blank

The preparation of the seventh edition of this established book on marineauxiliary machinery has necessitated the removal of some old material and theinclusion of new topics to make it relevant to the present day certificate ofcompetency examinations It is hoped that the line drawings, many of whichwere provided by Mr R C Dean, a former colleague in London, will be usefulfor the certificate of competency and other examinations The majority of otherillustrations and much of the basic text have been provided over the years bythe various firms listed in the Acknowledgements I am grateful to those firmswho have supplied me with material added in this edition

H D McGeorge

This page intentionally left blank

The author and publishers would like to acknowledge the cooperation of the following who have assisted in the preparation of the book by supplying information and illustrations, Alfa-Laval Ltd IMI-Bailey Valves Ltd.

APE-Allen Ltd IMO Industri.

ASEA, International Maritime Organisation Auto-Klean Strainers Ltd KaMeWa.

Bell & Howell Cons Electrodynamics Richard Klinger Ltd.

Blakeborough & Sons Ltd Kockums (Sweden).

Blohm & Voss A.G K.D.G Instruments Ltd.

Brown Bros & Co Ltd Lister Blackstone Mirrlees Marine Ltd B.S.R.A Lloyds Register of Shipping.

Bureau Veritas Mather & Platt Ltd.

Caird & Rayner Ltd Metering Pumps Ltd.

Caterpillar Traction Co Michell Bearings Ltd.

Chubb Fire Security Ltd Nash Engineering (G.B.) Ltd.

Clarke, Chapman Ltd Navire Cargo Gear Int AB.

Cockburn-Rockwell Ltd Norwinch.

Crane Packing Peabody Ltd.

W Crockatt & Sons Ltd Penwalt Ltd.

R C Dean Peter Brotherhood Ltd.

Deep Sea Seals Ltd Petters Ltd.

The Distillers Co Ltd (CO 2 Div.) Phillips Electrical Ltd.

Donkin & Co Ltd Thos Reid & Sons (Paisley) Ltd.

Fire Fighting Enterprises Ltd Ross-Turnbull Ltd.

Fisher Control Valves Ltd Royles Ltd.

G & M Firkins Ltd Ruston Paxman Diesels Ltd.

Foxboro-Yoxall Ltd Simplex-Turbulo Marine Ltd.

G.E.C.-Elliott Control Valves Ltd Serck Heat Exchangers Ltd.

Germannischer Lloyd Spirax-Sarco Ltd.

Glacier Metal Ltd Sofrance.

Hall Thermotank Ltd Sperry Marine Systems Ltd.

The Henri Kummerman Foundation Stella-Meta Filters Ltd.

Howden Godfrey Ltd Stone Manganese Marine Ltd.

Hamworthy Engineering Ltd Stothert & Pitt Ltd.

Harland & Wolff Ltd Svanehoj, Denmark.

John Hastie & Co Ltd Taylor Servomax.

Hattersley Newman Hender Ltd United Filters & Engineering Ltd.

Hawthorn Leslie (Engineers) Ltd Vickers Ltd.

Hindle Cockburns Ltd Vokes Ltd.

James Howden & Co Ltd Vosper Ltd.

F A Hughes & Co Ltd The Walter Kidde Co Ltd.

W C Holmes & Co Ltd Weir Pumps Ltd.

Howaldtswerke-Deutche Werft A.G Welin Davit & Engineering Ltd.

Hydraulics & Pneumatics Ltd Wilson-Elsan Ltd.

Worthington-Simpson Ltd.

This page intentionally left blank

1 Main propulsion services and

heat exchangers

The heat produced by running machinery, must be removed to ensure thesatisfactory functioning of the equipment Cooling is achieved primarilythrough circulation of water, oil and air but the abundant supply of sea water isnormally reserved for use as an indirect coolant because the dissolved saltshave a great potential for depositing scale and assisting in the setting up ofgalvanic corrosion cells Pollution of coastal areas by industrial and otherwastes has added to the problems of using sea water as a coolant

Circulating systems for motorships

The usual arrangement for motorships (Figure 1.1) has been to have sea-watercirculation of coolers for lubricating oil, piston cooling, jacket water, charge air,turbo-charger oil (if there are sleeve type bearings) and fuel valve cooling, plusdirect sea-water cooling for air compressors and evaporators The supply forother auxiliaries and equipment may be derived from the main sea-watersystem also

There may be two sea-water circulating pumps installed as main andstand-by units, or there may be a single sea-water circulating pump with astand-by pump which is used for other duties The latter may be a ballast pumpfitted with a primer and air separator Ship side valves, can be arranged withhigh and low suctions or fitted to water boxes High suctions are intended forshallow water to reduce the intake of sediment Low suctions are used at sea, toreduce the risk of drawing in air and losing suction when the ship is rolling Awater box should be constructed with a minimum distance of 330 mm betweenthe valve and the top, for accumulation of any air which is then removed by avent A compressed air or steam connection is provided for clearing any weed.Ship side valve bodies for the sea-water inlet must be of steel or other ductilemetal Alternative materials are bronze, spheroidal graphite cast iron,meehanite or another high-quality cast iron Ordinary grey cast iron hasproved to be unreliable and likely to fail should there be shock from an impact

or other cause Permissible cast irons must be to specification and obtainedfrom an approved manufacturer

Bronze has good resistance to corrosion but is expensive and therefore tends

to be used for smaller ship side valves Steel is cheaper, but prone to corrosion,

It may be cast or fabricated Unprotected steel valve casings and pipes will, in

Figure 1,1 Conventional sea-water circulation system

Main propulsion services and heat exchangers 3

the presence of sea water and bronze seats, valve lids and spindles, waste due togalvanic corrosion However, the presence of corroding iron or steel confersbenefits in sea-water systems The metal acts as a sacrificial anode andadditionally delivers iron ions which are carried through and give protection toother parts of system where they deposit

The fresh-water circuit comprising jacket water circulating pumps, fresh-watercoolers, cylinder jackets, cylinder heads, exhaust valves (if fitted), turbo-blowersand a branch to an evaporator, is under positive head, and therefore in a closedsystem with a header tank It is normal for there to be a blanked connectionbetween the sea-water system and engine jacket water circuit, for use in anemergency If the engine pistons are fresh-water cooled, the circuit may be inparallel with the jacket circuit but it is more likely to be separate Main andstand-by piston cooling water circulating pumps are mounted directly on thedrain tank so that with flooded suctions no primer is required The pistoncooling system embraces a separate cooler, the inlet manifold, telescopic pipes,pistons, outlet manifold, drain tank and pumps

The engine system temperatures are kept as high as practicable The systemshown has salt-water bypass valves on oil and water coolers for temperaturecontrol These are valves controlled by thermo-pneumatic devices It is usual tomake provision for warming the fresh circulating water before the mainengines are started, either by steam or by circulating from the auxiliary jacketwater cooling circuit

The auxiliary sea-water cooling circuit for generator diesel prime moversmay have its own sea inlet and pumps for circulation, with a cross connectionfrom the main sea-water circulation system Air compressors together with theinter- and after-coolers may be supplied with sea-water cooling in parallel withthe main system or alternatively, there may be crankshaft-driven pumps.Charge air coolers are sea-water circulated

The jacket water system for generator diesel prime movers is similar to thatfor the main engines, usually with a separate header tank Pumps for theservices are duplicated or cross connected

Sea-water pipes for circulation of cooling water, together with those forbilge and ballast systems, are prone to internal wastage from corrosion anderosion External corrosion is also a problem in the tank top area Steel pipesadditionally suffer from rusting

Control of temperature in heat exchangers

The three basic methods for controlling the temperature of the hot fluid in aheat exchanger when the cooling medium is sea-water, are:

1 to bypass a proportion or all of the hot fluid flow,

2 to bypass or limit the sea-water flow;

3 to control sea-water temperature by spilling part of the sea-water discharge backinto the pump suction

The last of these methods could be used in conjunction with one of the other

4 Main propulsion services and heat exchangers

two and it was resorted to when sea water was used for direct cooling of dieselengines It enabled the sea water to be passed through jackets at a temperaturewarmer than that of the sea Very cold sea water would cause severe thermalstress The temperature of sea water for direct cooling was kept to between 40°and 49' C, the upper limit being necessary to limit scale formation

Automatic control equipment for the system shown above, is based onusing a control valve to bypass the sea water at the outlet side of the heatexchanger This ensures that the heat exchanger is always full of sea water and

is particularly important if the heat exchanger is mounted high in the sea-watersystem and especially if it is above the water line Pneumatically operatedvalves may be fitted for temperature control, through bypassing the sea water,The flow of hot fluid through a heat exchanger may be controlled by asimilar bypass or by a control valve of the Walton wax-operated type, directlyactuated by a temperature sensor

Shell and tube coolers

Shell and tube heat exchangers for engine cooling water and lubricating oilcooling (Figure 1.2) have traditionally been circulated with sea water The seawater is in contact with the inside of the tubes, tube plates and water boxes Atwo-pass flow is shown in the diagram but straight flow is common in smallcoolers The oil or water being cooled is in contact with the outside of the tubesand the shell of the cooler Baffles direct the liquid across the tubes as it flowsthrough the cooler The baffles also support the tubes and form with them astructure which is referred to as the tube stack The usual method of securingthe tubes in the tube plates is to roll-expand them

Tubes of aluminium brass (76% copper; 22% zinc; 2% aluminium) are

Figure 1.2 Tube type cooler

Main propulsion services and heat exchangers 5

commonly employed and the successful use of this material has apparentlydepended on the presence of a protective film of iron ions, formed along thetube length, by corrosion of iron in the system Unprotected iron in waterboxes and in parts of the pipe system, while itself corroding, does assist inprolonging tube life This factor is well known (Cotton and Scholes, 1972) buthas been made apparent when iron and steel in pipe systems have beenreplaced by non-ferrous metals or shielded by a protective coating Theremedy in non-ferrous systems, has been to supply iron ions from othersources Thus, soft iron sacrificial anodes have been fitted in water boxes, ironsections have been inserted in pipe systems and iron has been introduced intothe sea water, in the form of ferrous sulphate The latter treatment consists ofdosing the sea water to a strength of 1 ppm for an hour per day for a few weeksand subsequently dosing again before entering and after leaving port for ashort period

Electrical continuity in the sea-water circulating pipework is importantwhere sacrificial anodes are installed Metal connectors are fitted across flangesand cooler sections where there are rubber joints and 'O' rings, whichotherwise insulate the various parts of the system

Premature tube failure can be the result of pollution in coastal waters orextreme turbulence due to excessive sea-water flow rates To avoid theimpingement attack, care must be taken with the water velocity through tubes.For aluminium-brass, the upper limit is about 2.5 m/s Although it is advisable

to design to a lower velocity than this — to allow for poor flow control - it isequally bad practice to have sea-water speeds of less than 1 /sec A more thanminimum flow is vital to produce moderate turbulence which is essential to theheat exchange process and to reduce silting and settlement in the tubes.Naval brass tube plates are used with aluminium-brass tubes The tube stacksare made up to have a fixed tube plate at one end and a tube plate at the otherend (Figure 1.3 ) which is free to move when the tubes expand or contract Thetube stack is constructed with baffles of the disc and ring, single or doublesegmental types The fixed end tube plate is sandwiched between the shell andwater box, with jointing material, Synthetic rubber 'O' rings for the slidingtube plate permit free expansion The practice of removing the tube stack andreplacing it after rotation radially through 180 degrees, is facilitated by the

Figure 1,3 Detail of cooler expansion arrangement

6 Main propulsion services and heat exchangers

type of cooler described This may prolong cooler life by reversing the flow sothat tube entrances, which are prone to impingement damage, become outlets.Cooler end covers and water boxes are commonly of cast iron or fabricatedfrom mild steel Unprotected cast iron in contact with sea water, suffers fromgraphitization, a form of corrosion in which the iron is removed and only thesoft black graphite remains

The shell is in contact with the liquid being cooled which may be oil, distilled

or fresh water with corrosion inhibiting chemicals It may be of cast iron orfabricated from steel Manufacturers recommend that coolers be arrangedvertically Where horizontal installation is necessary, the sea water shouldenter at the bottom and leave at the top Air in the cooler system willencourage corrosion and air locks will reduce the cooling area and causeoverheating Vent cocks should be fitted for purging air and cocks or a plug arerequired at the bottom, for draining

Clearance is required at the cooler fixed end for removal of the tube stack,

Plate type heat exchangers

The obvious feature of plate type heat exchangers, is that they are easilyopened for cleaning The major advantage over tube type coolers, is that theirhigher efficiency is reflected in a smaller size for the same cooling capacity.They are made up from an assembly of identical metal pressings (Figure1.4a) with horizontal or chevron pattern corrugations; each with a nitrilerubber joint The plates, which are supported beneath and located at the top byparallel metal bars, are held together against an end plate by clamping bolts.Four branch pipes on the end plates, align with ports in the plates throughwhich two fluids pass Seals around the ports are so arranged that one fluidflows in alternate passages between plates and the second fluid in theintervening passages, usually in opposite directions

The plate corrugations promote turbulence (Figure 1.4b) in the flow of bothfluids and so encourage efficient heat transfer Turbulence as opposed tosmooth flow causes more of the liquid passing between the plates to come intocontact with them It also breaks up the boundary layer of liquid which tends toadhere to the metal and act as a heat barrier when flow is slow Thecorrugations make the plates stiff so permitting the use of thin material Theyadditionally increase plate area Both of these factors also contribute to heatexchange efficiency

Excess turbulence, which can result in erosion of the plate material, isavoided by using moderate flow rates However, the surfaces of plates whichare exposed to sea water are liable to corrosion/erosion and suitable materialsmust be selected Titanium plates although expensive, have the best resistance

to corrosion/erosion Stainless steel has also been used and other materialssuch as aluminium-brass The latter may not be ideal for vessels which operate

in and out of ports with polluted waters

The nitrile rubber seals are bonded to the plates with a suitable adhesive.Removal is facilitated with the use of liquid nitrogen which freezes, makes

Main propulsion services and heat exchangers 7

Figure 1.4a Plate type heat exchanger

Figure 1.4b Turbulence produced by plate corrugations

brittle and causes contraction of the rubber seal which is then easily brokenaway Other methods of seal removal result in plate damage

Nitrile rubber is suitable for temperatures of up to about 110°C At highertemperatures the rubber hardens and loses its elasticity The joints are squeezedwhen the plates are assembled and clamping bolts are tightened after cleaning

8 Main propulsion services and heat exchangers

Overtightening can cause damage to the plates, as can an incorrect tighteningprocedure A torque spanner can be used as directed when clamping bolts aretightened; cooler stack dimensions can also be checked

Titanium

The corrosion resistance of titanium has made it a valuable material for use insea-water systems whether for static or fast flow conditions The metal is lightweight (density 4.5 kg/m3) and has good strength It has a tolerance to fastliquid flow which is better than that of cupro-nickel It is also resistant tosulphide pollution in sea water While titanium has great corrosion resistancebecause it is more noble than other metals used in marine systems, it does tend

to set up galvanic cells with them The less noble metals will suffer wastageunless the possibility is reduced by careful choice of compatible materials,coating of the titanium, insulation or the use of cathodic protection,

Charge air coolers

The charge air coolers fitted to reduce the temperature of air after theturbo-charger and before entry to the diesel engine cylinder, are provided withfins on the heat transfer surfaces to compensate for the relatively poor heattransfer properties of air Solid drawn tubes with a semi-flattened cross section,have been favoured (Figure 1.5a) These are threaded through the thin copperfin plates and bonded to them with solder for maximum heat transfer Tubeends are fixed into the tube plates (Figure 1.5b) by being expanded and soldered.Cooling of the air results in precipitation of moisture which is removed by

Figure 1.5a Detail of charge air cooler tube arrangement

Main propulsion services and heat exchangers 9