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WÄRTSILÄ ENVIRONMENTAL PRODUCT GUIDE

WÄRTSILÄ® is a registered trademark. Copyright © 2010 Wärtsilä Corporation.

Wärtsilä is a global leader in complete lifecycle power solutions for the

marine and energy markets. By emphasising technological innovation

and total efficiency, Wärtsilä maximises the environmental and economic

performance of the vessels and power plants of its customers. Wärtsilä is

listed on the NASDAQ OMX Helsinki, Finland.

IntroductionThis Product Guide provides data and system proposals for the early design phase of marine installations.For contracted projects specific instructions for planning the installation are always delivered. Any dataand information herein is subject to revision without notice. This 1/2013 issue replaces all previous issuesof the Wärtsilä Environmental Systems Product Guides.

UpdatesPublishedIssue

Minor text updates10.01.20131/2013

General updates28.11.20122/2012

Ballast water treatment added and general updates12.7.20121/2012

Exhaust gas temperature table updated.5.10.20113/2011

Formula for calculating Compressed Air Consumption updated.24.8.20112/2011

SCR Reactor sizes and dimensions table, Wärtsilä OWS 500 unit added, SOx EmissionControl Chapter updated

30.6.20111/2011

SOx Emissions Control Chapter added12.08.20103/2010

SCR Reactor sizes and dimensions table14.06.20102/2010

First issue of the Product Guide.16.04.20101/2010

Wärtsilä, Ship Power 4-stroke

Vaasa, January 2013

THIS PUBLICATION IS DESIGNED TO PROVIDE AS ACCURATE AND AUTHORITATIVE INFORMATION REGARDING THE SUBJECTS COVERED ASWAS AVAILABLE AT THE TIME OF WRITING. HOWEVER, THE PUBLICATION DEALS WITH COMPLICATED TECHNICAL MATTERS AND THE DESIGNOF THE SUBJECT AND PRODUCTS IS SUBJECT TO REGULAR IMPROVEMENTS, MODIFICATIONS AND CHANGES. CONSEQUENTLY, THE PUB-LISHER AND COPYRIGHT OWNER OF THIS PUBLICATION CANNOT TAKE ANY RESPONSIBILITY OR LIABILITY FOR ANY ERRORS OR OMISSIONSIN THIS PUBLICATION OR FOR DISCREPANCIES ARISING FROM THE FEATURES OF ANY ACTUAL ITEM IN THE RESPECTIVE PRODUCT BEINGDIFFERENT FROM THOSE SHOWN IN THIS PUBLICATION. THE PUBLISHER AND COPYRIGHT OWNER SHALL NOT BE LIABLE UNDER ANY CIR-CUMSTANCES, FOR ANY CONSEQUENTIAL, SPECIAL, CONTINGENT, OR INCIDENTAL DAMAGES OR INJURY, FINANCIAL OR OTHERWISE,SUFFERED BY ANY PART ARISING OUT OF, CONNECTED WITH, OR RESULTING FROM THE USE OF THIS PUBLICATION OR THE INFORMATIONCONTAINED THEREIN.

COPYRIGHT © 2013 BY WÄRTSILÄ FINLAND Oy

ALL RIGHTS RESERVED. NO PART OF THIS PUBLICATION MAY BE REPRODUCED OR COPIED IN ANY FORM OR BY ANY MEANS, WITHOUT PRIORWRITTEN PERMISSION OF THE COPYRIGHT OWNER.

Product Guide - 1/2013 iii

Wärtsilä Environmental Product GuideIntroduction

Table of Contents

11. International Maritime Organisation ........................................................................................................11.1 MARPOL Annex VI - Air Pollution ....................................................................................................11.1.1 Nitrogen Oxides, NOx Emissions ...................................................................................41.1.2 Sulphur Oxides, SOx emissions .....................................................................................41.2 Standards for Ballast Water Management .......................................................................................41.2.1 United States Coast Guard ............................................................................................

52. NOx Emissions Control ............................................................................................................................52.1 The Wärtsilä NOx Reducer (NOR) ...................................................................................................52.1.1 Solution for meeting NOx reduction requirements ........................................................52.1.2 Selective catalytic reduction ..........................................................................................62.1.3 System overview ............................................................................................................

122.1.4 Operating conditions and limitations ..............................................................................132.1.5 System design data ........................................................................................................152.1.6 Recommendations .........................................................................................................152.1.7 Service and maintenance ...............................................................................................

163. SOx Emissions Control ............................................................................................................................163.1 The Wärtsilä Closed loop Scrubber ..................................................................................................163.1.1 Fresh water SOx scrubber ..............................................................................................193.1.2 Main stream scrubber .....................................................................................................203.1.3 Integrated scrubber ........................................................................................................223.1.4 Fresh water system ........................................................................................................223.1.5 Seawater system ...........................................................................................................233.1.6 Alkali feed system ..........................................................................................................273.1.7 Scrubbing water system .................................................................................................273.1.8 Bleed-off system .............................................................................................................283.1.9 Control and monitoring ...................................................................................................303.1.10 Power demand ...............................................................................................................303.1.11 Maintenance ...................................................................................................................313.1.12 Exhaust gas system .......................................................................................................

324. Bilge Systems ...........................................................................................................................................324.1 Wärtsilä Oily Water Separator (OWS) ..............................................................................................324.1.1 System overview ............................................................................................................374.1.2 Options ...........................................................................................................................

385. Ballast Water Management ......................................................................................................................385.1 Wärtsilä AQUARIUS EC ..................................................................................................................385.1.1 System overview ...........................................................................................................405.1.2 Operating principle .........................................................................................................415.2 Wärtsilä AQUARIUS UV ..................................................................................................................415.2.1 System overview ...........................................................................................................435.2.2 Operating principle .........................................................................................................445.3 Wärtsilä Ballast Water Treatment System (BWTS) .........................................................................445.3.1 Integrated Filter, UV System ..........................................................................................455.3.2 Regulatory Requirements ..............................................................................................455.3.3 Wärtsilä BWTS general description ................................................................................

476. Crankcase Vent Systems ..........................................................................................................................476.1 Oil Mist Separator Module ................................................................................................................

487. ANNEX ........................................................................................................................................................487.1 Unit conversion tables ......................................................................................................................487.1.1 Prefix ..............................................................................................................................497.2 Collection of drawing symbols used in drawings ..............................................................................

iv Product Guide - 1/2013

Wärtsilä Environmental Product GuideTable of Contents

1. International Maritime OrganisationThe International Maritime Organisation (IMO) is an agency of the United Nations which has been formedto promote maritime safety. The increasing concern of air pollution has resulted in the introduction of exhaustgas emission controls to the marine industry; IMO ship pollution rules are contained in the “InternationalConvention on the Prevention of Pollution from Ships”, which represents the first set of regulations onmarine exhaust emissions, known as MARPOL 73/78, 1973 as modified by the Protocol of 1978. Marpol73/78 is the most important international marine environmental convention. It was designed to minimisepollution of the seas, including dumping, and oil and exhaust pollution. Its stated object is to preserve themarine environment through the complete elimination of pollution by oil and other harmful substances andthe minimization of accidental discharge of such substances.

The original MARPOL Convention was signed on 17 February 1973, but did not come into force. The currentConvention is a combination of 1973 Convention and the 1978 Protocol. It entered into force on 2 October1983. Marpol contains 6 annexes, concerned with preventing different forms of marine pollution from ships:

Annex I - Oil

Annex II - Noxious Liquid Substances carried in Bulk

Annex III - Harmful Substances carried in Packaged Form

Annex IV - Sewage

Annex V - Garbage

Annex VI - Air Pollution

1.1 MARPOL Annex VI - Air PollutionThe MARPOL 73/78 Annex VI entered into force 19 May 2005. The Annex VI sets limits on Nitrogen Oxides,Sulphur Oxides and Volatile Organic Compounds emissions from ship exhausts and prohibits deliberateemissions of ozone depleting substances.

1.1.1 Nitrogen Oxides, NOx Emissions

The MARPOL 73/78 Annex VI regulation 13, Nitrogen Oxides, applies to diesel engines over 130 kW installedon ships built (defined as date of keel laying or similar stage of construction) on or after January 1, 2000.The NOx emissions limit is expressed as dependent on engine speed. IMO has developed a detailed NOxTechnical Code which regulates the enforcement of these rules.

EIAPP Certification

An EIAPP (Engine International Air Pollution Prevention) Certificate is issued for each engine showing thatthe engine complies with the NOx regulations set by the IMO.

When testing the engine for NOx emissions, the reference fuel is Marine Diesel Oil (distillate) and the testis performed according to ISO 8178 test cycles. Subsequently, the NOx value has to be calculated usingdifferent weighting factors for different loads that have been corrected to ISO 8178 conditions. The usedISO 8178 test cycles are presented in the following table.

Table 1.1 ISO 8178 test cycles

100100100100100Speed (%)D2: Auxiliary engine

10255075100Power (%)

0.10.30.30.250.05Weightingfactor

100100100100Speed (%)E2: Diesel electric propul-sion or controllable pitchpropeller

255075100Power (%)

0.150.150.50.2Weightingfactor

Product Guide - 1/2013 1

Wärtsilä Environmental Product Guide1. International Maritime Organisation

638091100Speed (%)E3: Fixed pitch propeller

255075100Power (%)

0.150.150.50.2Weightingfactor

IdleIntermediateRatedSpeedC1:"Variable -speed and -loadauxiliary engine application"

05075100105075100Torque (%)

0.150.10.10.10.10.150.150.15Weightingfactor

Engine family/group

As engine manufacturers have a variety of engines ranging in size and application, the NOx Technical Codeallows the organising of engines into families or groups. By definition, an engine family is a manufacturer’sgrouping, which through their design, are expected to have similar exhaust emissions characteristics i.e.,their basic design parameters are common. When testing an engine family, the engine which is expectedto develop the worst emissions is selected for testing. The engine family is represented by the parent engine,and the certification emission testing is only necessary for the parent engine. Further engines can be certifiedby checking document, component, setting etc., which have to show correspondence with those of theparent engine.

Technical file

According to the IMO regulations, a Technical File shall be made for each engine. The Technical File containsinformation about the components affecting NOx emissions, and each critical component is marked witha special IMO number. The allowable setting values and parameters for running the engine are also specifiedin the Technical File. The EIAPP certificate is part of the IAPP (International Air Pollution Prevention) Certi-ficate for the whole ship.

IMO NOx emission standards

The first IMO Tier 1 NOx emission standard entered into force in 2005 and applies to marine diesel enginesinstalled in ships constructed on or after 1.1.2000 and prior to 1.1.2011.

The Marpol Annex VI and the NOx Technical Code were then undertaken a review with the intention to furtherreduce emissions from ships. In the IMO MEPC meeting in April 2008 proposals for IMO Tier 2 and IMOTier 3 NOx emission standards were agreed. Final adoption for IMO Tier 2 and Tier 3 was taken by IMO/MEPC58 in October 2008.

The IMO Tier 2 NOx standard entered into force 1.1.2011 and replaced the IMO Tier 1 NOx emissionstandard globally. The Tier 2 NOx standard applies for marine diesel engines installed in ships constructedon or after 1.1.2011.

The IMO Tier 3 NOx emission standard will enter into force from 1 January 2016, but the Tier 3 standardwill only apply in designated special areas. The ECA areas are to be defined by the IMO. So far, the NorthAmerican ECA and the US Caribbean Sea ECA has been defined. The IMO Tier 2 NOx emission standardwill apply outside the Tier 3 designated areas. The Tier 3 NOx emission standard is not applicable to recre-ational ships < 24 m and for ships with combined propulsion power < 750 kW subject to satisfactorydemonstration to Administration that the ship cannot meet Tier 3.

The NOx emissions limits in the IMO standards are expressed as dependent on engine speed. These areshown in figure 13.1.

2 Product Guide - 1/2013


Figure 1.1 IMO NOx emission limits

IMO Tier 1 NOx emission standard

The IMO Tier 1 NOx emission standard applies to ship built from year 2000 until end 2010.

The IMO Tier 1 NOx limit is defined as follows:

= 45 x rpm-0.2 when 130 < rpm < 2000NOx [g/kWh]

The NOx level is a weigthed awerage of NOx emissions at different loads, in accordance with the applicabletest cycle for the specific engine operating profile.

IMO Tier 2 NOx emission standard (new ships 2011)

The IMO Tier 2 NOx emission standard entered into force in 1.1.2011 and applies globally for new marinediesel engines > 130 kW installed in ships which keel laying date is 1.1.2011 or later.



The NOx level is a weighted average of NOx emissions at different loads, and the test cycle is based on theengine operating profile according to ISO 8178 test cycles. IMO Tier 2 NOx emission levels correspondsto about 20% reduction from the IMO Tier 1 NOx emission standard. This reduction is reached with engineoptimization.

IMO Tier 3 NOx emission standard (new ships 2016, in designated areas)

The IMO Tier 3 NOx emission standard will enter into force from 1 January 2016. The IMO Tier 3 NOxstandard applies only for new marine diesel engines > 130 kW installed in ships which keel laying date is1.1.2016 or later when operating inside designated emission control areas (ECA).



The IMO Tier 3 NOx emission level corresponds to an 80% reduction from the IMO Tier 1 NOx emissionstandard. The reduction can be reached by applying a secondary exhaust gas emission control system. A



Selective Catalytic Reduction (SCR) system is an efficient way to reach the NOx reduction needed for theIMO Tier 3 standard.

1.1.2 Sulphur Oxides, SOx emissions

Marpol Annex VI has set a maximum global fuel sulphur limit of currently 3,5% (from 1.1.2012) in weightfor any fuel used on board a ship. Annex VI also contains provisions allowing for special SOx EmissionControl Areas (SECA) to be established with more stringent controls on sulphur emissions. In a “SOxEmission Control Area”, which currently comprises the Baltic Sea, the North Sea, the English Channel andthe area outside North America (200 nautical miles), the sulphur content of fuel oil used onboard a shipmust currently not exceed 1% in weight. On january1, 2014, the US Caribbean Sea SECA will become ef-fective.

The Marpol Annex VI has undertaken a review with the intention to further reduce emissions from ships.The upcoming limits for future fuel oil sulphur contents are presented in the following table.

Table 1.2 Fuel sulphur caps

Date of implementationAreaFuel sulphur cap

1 July 2010SECA AreasMax. 1.0% S in fuel

1 January 2012GloballyMax 3.5% S in fuel

1 January 2015SECA AreasMax. 0.1% S in fuel

1 January 2020GloballyMax. 0.5% S in fuel

Abatement technologies including scrubbers are allowed as alternatives to low sulphur fuels. The exhaustgas system can be applied to reduce the total emissions of sulphur oxides from ships, including both aux-iliary and main propulsion engines, calculated as the total weight of sulphur dioxide emissions.

1.2 Standards for Ballast Water ManagementThe International Maritime Organization (IMO) adopted in February 2004 the International Convention forthe Control and Management of Ships Ballast Water & Sediments (BWM Convention). The Convention willenter into force 12 months after ratification by 30 States, representing 35 per cent of world merchant shippingtonnage. The convention requires that all ships install Ballast Water Management Systems (BWMS) to treatthe ballast water before it is released to the environment.

In the convention, the IMO has specified ballast water performance standards (Section D - Standards forBallast Water Management) as follows: “Ships conducting ballast water management shall discharge < 10viable organisms per m3 ≥ 50 micrometres in minimum dimension and < 10 viable organisms per milliliter< 50 micrometres in minimum dimension and ≥ 10 micrometres in minimum dimension; and discharge ofthe indicator microbes shall not exceed the specified concentrations.”

The ballast water regulations are introduced as to prevent sensitive ecosystems being ruined by foreignmicroorganisms, which have been transported with the ballast water in ships.

1.2.1 United States Coast GuardApart from the regulations from the IMO, the The United States Coast Guard are setting their own rules forBallast Water Management. The USCG final rule addressing “Standards for Living Organisms in Ship’sBallast Water Discharged in US Water” (BWDS) was published in the US Federal Register on 23 March2012. The rule will effective on 21 June 2012. The US Coast Guard Rule will affect vessels, US and foreign,which operate in the US waters, are bound for ports or places in the US, and are equipped with ballasttanks. These vessels are required to install and operate a USCG approved BWMS before discharging ballastwater into US waters.



2. NOx Emissions Control

2.1 The Wärtsilä NOx Reducer (NOR)

2.1.1 Solution for meeting NOx reduction requirementsWärtsilä's NOx reducer (NOR) system is an emission after-treatment system compliant with various NOxemission reduction needs, such as IMO Tier 3. It can also be optimised for Norwegian NOx fund operationor other NOx emission limits as per customer requirements.

Figure 2.1 NOR system overview

2.1.2 Selective catalytic reductionThe Wärtsilä NOx reducer is based on the Selective Catalytic Reduction (SCR) technique for Nitrogen Oxide(NOx) reduction. The Selective Catalytic Reduction system reduces the level of nitrogen oxide in the exhaustgas from the engine by means of catalyst elements and a reducing agent. In the process a reducing agentof an urea water solution is added to the exhaust gas stream. The water in the urea solution is evaporatedas the solution is injected into the hot exhaust gas. The high temperature also induces thermal decompos-ition of the urea ((NH2)2CO) into ammonia (NH3) and carbon dioxide (CO2):

(NH2)2CO + H2O → 2NH3 + CO2

Exhaust gas NOx emissions are thereafter transformed into molecular nitrogen (N2) and water (H2O), asthey react with the ammonia at a catalytic surface:

4NO + 4NH3 + O2 → 4N2 + 6H2O

6NO2 + 8NH3 → 7N2 + 12H2O.

The catalytic elements are located inside a metallic reactor structure located in the exhaust gas line. Theend products of the reaction are pure nitrogen and water, i.e. major constituents of ambient air. No liquidor solid by-products are produced.

The efficiency of the catalytic reduction depends on a number of factors, including the dosage of the reducingagent, the volume of catalyst elements and the exhaust gas temperature. Normally, a NOx reduction levelof 90% can be reached.


Wärtsilä Environmental Product Guide2. NOx Emissions Control

2.1.3 System overviewThe Wärtsilä NOx Reducer is as standard available in 40 different sizes to cover the 4-stroke engine portfolio.

A pump unit transfers urea from the storage tank to the dosing unit, which regulates the flow of urea to theinjection system based on the operation of the engine. The dosing unit also controls the compressed airflow to the injector.

The urea injector sprays reducing agent into the exhaust gas duct. After injection of the reducing agent,the exhaust gas flows through the mixing pipe to the reactor, where the catalytic reduction takes place.The reactor is equipped with a soot blowing system for keeping the catalyst elements clean. Figure 2.1presents an overview of the system.

The main components that are included in the standard scope of supply are:

• Reactor housing

• Catalyst elements

• Soot blowing unit

• Urea injection and mixing unit

• Urea dosing unit

• Control and automation unit

• Urea pumping unit

The standard scope of supply may also be extended with the following:

• NOx feedback monitoring system

• Urea standby pump

Other essential components that are optional in the scope of supply are:

• Mixing duct

• Compressor station (compressed air for urea injection and soot blowing system)

• Urea tank

• Insulation

• Expansion bellows incl. counter flanges (set)

• Support for ducting and reactor

• Piping and valves for selective catalytic reduction system (set)

The SCR process is shown in the attached SCR system P&I diagram.



Figure 2.2 P&I diagram, SCR system (DAAE092878_h)

System components

Urea tank11T03Urea filter11F04

Manual operated valve11V01Compressed air filter11F05

Flow control valve11V02Flowmeter11I01

Drain valve11V03Urea pump unit11N05

Solenoid valve11V07Soot blowing system11N07

Safety valve11V08Dosing unit11N06

Non-return valve11V09Urea injection unit11N08

Pressure damper11Z01SCR Reactor11N09

Pressure control valve11V11Control system11N11

Overflow valve11V12Urea transfer pump11P04



SCR Reactor

One SCR Reactor is installed per engine and exhaust gas pipe. The reactor is a steel casing consisting ofan inlet and an outlet cone, catalyst layers, a steel structure for supporting the catalyst layers and a sootblowing system. Compressed air connections for soot blowing are installed at each catalyst layer. The re-actor is equipped with a differential pressure transmitter for monitoring the condition of the catalyst elements,and a temperature transmitter for monitoring the exhaust gas outlet temperature. The reactor is also equippedwith manhole(s) for the inspection of ducts and maintenance doors for service/replacement of the catalyticelements.

The standard reactor is designed for the initial loading of two catalyst layers and can be installed eithervertically or horizontally onboard the ship. The standard reactor main dimensions, weights, pipe connectionsizes and indicative minimum mixing pipe length are shown in table 2.1. (The reactor dimensions arepresented with 150 mm insulation. The insulation is optionally included in delivery). Inlet and outlet flangeDN can be modified to fit case specific requirements. Should there also be any specific space restrictions,the NOR reactor and mixing duct dimensions can be tailor made upon request.

The standard reactor is dimensioned for a NOx reduction level from the IMO Tier 2 to the IMO Tier 3 NOxlevel and for fuel oil qualities with a fuel sulphur content of max. 1%. For installations where the NOx reductionlevel deviates from the IMO Tier 2 to the Tier 3 reduction level, or where fuel oil with a fuel sulphur contentof above 1% will be used, the reactor dimensions should be checked case specifically.

Catalyst elements

The catalyst elements are located in element frames in the catalyst reactor. The brick-shaped catalyst ele-ments have a honeycomb structure to increase the catalytic surface. Vanadium pentoxide (V2O5) is usedas the catalytic material. The efficiency of the catalyst decreases with time, maily due to thermal load andsmall amounts of catalyst poisons. When the catalytic activity has decreased too much, the catalyst mustbe changed. The lifetime of the catalyst depends on the fuel type and other operating conditions. The typ-ical lifetime is 4 - 6 years.

Soot blowing system

The soot blowing system is used for avoiding dust deposits on the catalyst. Each reactor is provided withan automatically operated soot blowing unit. The system operates with compressed air and consists ofseveral nozzles positioned on opposite reactor walls for ensuring efficient cleaning of the whole elementsurface area. The air supply has to be in operation at all times while the engines are running.

Urea pumping and dosing system

The urea pump unit supplies urea to the dosing system and maintains a sufficient pressure in the urea lines.The main component of the unit is an electrically driven pump (screw pump), which is mounted on a frametogether with the necessary accessories. A suction filter protects the pump and the downstream equipmentfrom impurities. Excess urea returns to the storage tank through an overflow line.

The dosing unit defines the correct urea dosing rate for the injection system and adjusts the urea flow ac-cordingly by a control valve. The components in the unit are mounted on a frame, forming a compactmodule. In addition to the equipment for reducing agent dosing, the unit includes components for compressedair regulation and also the electrical cabinet for controlling the SCR system. The dosing unit should be in-stalled close to the urea injection point, for instance in the engine room.

One pump unit can be used for several SCR reactors while one dosing unit is installed for each SCR reactor.



Control system

The components in the NOR system are controlled by a Wärtsilä embedded control system. The controlunit is connected to the engine control system, enabling automatic adjustment of the urea injection basedon the operation of the engine. The SCR unit receive the engine load and speed signal, and adjusts theurea dosing accordingly. The urea dosing is regulated by adjusting the position of the flow control valve.The operation interface of the SCR system may also be integrated to the engine control system.

The system also handles the sequencing of valves for soot blowing and cleaning of the injection nozzle.The soot blowers are operated automatically at a preset interval. If the system is in auto mode, the ureainjection is automatically activated when the engine starts. Correspondingly, when the engine stops, theurea dosing is shut off. The injection system is automatically purged of urea before start up and after a stopof the NOR. The control system is mounted on the dosing unit and one control system is installed for eachSCR reactor.

Urea injection unit and mixing duct

The urea injection unit is a short pipe consisting of an urea injector and mixing plate. It is located on theexhaust gas pipe before the mixing duct and the SCR reactor. The injection unit operates with compressedair and injects the urea solution to the exhaust gas stream. One urea injection unit is installed for each SCRreactor. After the injection of the reducing agent, the exhaust gas flow passes through a mixing duct. Themixing duct gives time for the urea to transform into ammonia and mix homogeneously before it reachesthe catalyst elements. Indicative lengths for the mixing duct can be seen in table 2.1. The mixing duct isoptionally included in the scope of supply.



Figure 2.3 SCR Reactor (DAAF018501) (Here presented with 150 mm insulation)



Table 2.1 SCR Reactor sizes and dimensions

Mixing pipe,total lenght(m)(includesstraightlenght)

Mixing pipe,straight length(m)(bends are al-lowed afterstraightlenght)

F(mm)

W (mm)(incl. 150mminsulation)

H (mm)(incl. 150mminsulation)

L (mm)(incl.cones)

Weight(kg) (incl.catalystelements)

Reactoroutlet DOFlangeDN

Reactorinlet DIFlangeDN

Engine poweroutput (kW)

ReactorSize

3.02.3125840840300011003003500...4001

3.22.4125840100030001200350400401...5502

3.42.51251000100031161500400450551...7003

3.62.61251000116031161600400500701...9004

3.82.71251160116032302000450550901...11005

3.92.712511601320323021005006001101...13506

3.92.512513201320334625005507001351...16007

4.22.812513201480334626006007001601...18508

4.12.612514801480346030006008001851...21509

4.52.912514801640346031007008002151...245010

4.32.712516401640357835007009002451...280011

4.02.6125164018003578360080010002801...315012

4.42.9125180018003692410080010003151...360013

4.22.7125180019603692420090011003601...400014

4.02.6125196019603808470090012004001...440015

4.32.81251960212038084800100012004401...480016

4.12.71252120212039245300100013004801...530017

4.42.91252120228039245400110013005301...585018

4.32.81252280228040405900110014005851...630019

4.63.01252280244040406000120014006301...680020

4.42.92252440244041566600120015006801...740021

4.73.12252440260041566800120015007401...800022

4.53.02252600260042707300120016008001...860023

4.83.22252600276042707500130016008601...920024

4.63.12252760276044208300130017009201...990025

4.93.32252760292044208500140017009901...1060026

4.73.222529202920468894001400180010601...1120027

4.63.122529203080468896001500190011201...1190028

4.83.3225308030804716105001500190011901...1270029

5.13.4225308032404716107001600190012701...1340030

4.93.4325324032404866117001600200013401...1420031

5.13.5325324034004866119001700200014201...1500032

5.43.6325340034005014128001700200015001...1580033

4.93.4325340035605014130001800220015801...1660034

5.13.5325356035605162140001800220016601...1750035

5.33.6325356037205162143001900220017501...1840036

5.53.7325372037205412173001900220018401...1930037

5.73.9325372038805412175002000220019301...2020038

5.94.0325388038805560206002000220020201...2120039

6.24.1325388040405560209002000220021201...2220040



2.1.4 Operating conditions and limitations

Pressure drop over the SCR reactor

Pressure is measured continuously before and after the reactor. The pressure drop over the SCR systemis designed to be below 15mbar at 100% engine load. The urea injection will be stopped automatically ifthe the design value is exceeded.

Exhaust gas temperature for different fuel types

The working temperature of the SCR system is dependent on the fuel sulphur content and fuel type. Thefollowing figure indicates the trade off between the minimum and the maximum recommended exhaustgas temperature and the sulphur content of the fuel oil in order to achieve good efficiency and durability.

Figure 2.4 Recommended minimum and maximum catalyst operating temperature for continous operations vs Sulphurcontent in the fuel oil.



2.1.5 System design data

Urea solution quality

Wärtsilä recommends the use of 40 weight % aqueous urea solution as the reducing agent in the SCR unit,but other solutions such as 32% may also be used. The urea solution concentration is taken into accountwhen designing the urea tank and selecting the urea pumping and dosing units. No blending between dif-ferent concentrations is allowed. The urea solution quality requirements are specified in tables 2.3 and 2.4,see ISO 22241 for reference. It is not allowed to use agricultural or fertilizer urea.

Table 2.2 Quality requirements for 40% urea solution

Typical valueMax. limitMin. limitUnitCharacteristics

40.041.039.0weight-%Urea content

1115.01105.0kg/m3Density

0.8%Biuret

100.0mg/kgAldehydes

50.0mg/kgInsolubles

1.0mg/kgPhosphates (PO4)

1.0mg/kgCalcium

1.0mg/kgIron

1.0mg/kgMagnesium

1.0mg/kgSodium

1.0mg/kgPotassium

Table 2.3 Quality requirements for 32% urea solution

Typical valueMax. limitMin. limitUnitCharacteristics

32.533.231.8weight-%Urea content

1093.01087.0kg/m3Density

0.3%iuret

5.0mg/kgAldehydes

20.0mg/kgInsolubles

0.5mg/kgPhosphate (PO4)

0.5mg/kgCalcium

0.5mg/kgIron

0.2mg/kgCopper

0.2mg/kgZinc

0.2mg/kgChromium

0.2mg/kgNickel

0.5mg/kgAluminium

0.5mg/kgMagnesium

0.5mg/kgSodium

Urea consumption

Urea consumption is directly proportional to the NOx reduction amount over the SCR catalysts. In realitythe NOx from the engine deviates due to the ambient air conditions and engine related issues. During thecommissioning of the Wärtsilä NOx reducer system, the NOx deviations are taken into account in the dosingtuning. The typical urea consumption for reducing the NOx emissions from the IMO Tier 2 to the IMO Tier3 NOx level is 15l/MWh at 85% engine load. The consumption can furthermore be optimised taking intoaccount the IMO EIAPP cycle weighting factors and engine operation profile. The expected consumptioncan be calculated according to the formula:



Figure 2.5 Formula for Urea consumption

where:

Urea solution consumption [l/h]V urea =

Engine power output [kW]P engine =

NO2 (NOx) from engine - NOx after SCR [g/kWh]m NO2 =

Urea ((NH2)2CO) molar mass [g/mol] = 60.07M urea =

NO2 molar mass [g/mol] = 46.01M NO2 =

Urea solution concentration [weight-%]C urea =

Urea density [kg/l] ~1.1ρ urea =

Compressed air quality

The quality of compressed air needed for the reducing agent and soot blowing must fulfill the following re-quirements. Purity class 2 with respect to particles and oil and purity class 3 with respect to water, accordingto the specification in ISO 8573-1. The quality requirements are presented in table 2.5.

Table 2.4 Quality requirements for the compressed air

Maximum number per m3Particle size d [μm]

100 0000.1 < d ≤ 0.5

10000.5 < d ≤ 1.0

101.0 < d ≤ 5.0

ValueCharacteristics

max. +3 °CPressure dew point

mx. 0.1 mg/m3Total oil concentration (aerosol, liquid and vapour)

Compressed air consumption

Compressed air is required for urea injection, soot blowing operation and soot blowing valves cooling. Thecompressed air pressure for urea feeding is 4 bar(g), and for the soot blowing system 8 bar(g). The part ofthe soot blowing system air consumption (operation + valve cooling) is as a standard 6 Nm3/h.

The total maximum compressed air consumption for urea feeding and soot blowing system is calculatedas follows:

Max air consumption for 40% urea solution (Nm3/h) = Pengine * 0.0066 + 15.7

Max air consumption for 32% urea solution (Nm3/h) = Pengine * 0.009 + 15.6

Where:

Pengine = Engine power output (kW)

Nm3 is defined at 0 °C and 101325 Pa

If the urea solution concentration is not known please use the formula for 32% urea solution.

The maximum air consumption occurs only during urea injector purging. The air consumption during oper-ation on 85% engine load is typically >20% lower than the max consumption.

Electrical consumption

Electrical power is used for running the pumps and the control system. Typical power consumption for anoperational dosing unit including control system is 0.2 kW. For the pump unit the typical power consumptionis installation dependant but maximum 1.1 kW.



2.1.6 Recommendations

- Piping

The recommended material for piping is stainless steel (AISI 316) and for seals EDPM. Copper and its alloysmust be avoided. The temperature of the urea solution must be kept between +5 and +35 degrees C,therefore insulation and trace heating might be needed in some installations.

- Urea tank

The capacity of the main urea tank should be calculated for proper and defined duration considering themaximum urea solution consumption.

The urea tank must be made of a material that meets the requirements for storing urea (e.g. stainless steel),please refer to ISO 22241.The recommended storage temperature for the urea solution is +5 to +35 degreesC. Therefore insulation and heating might be needed in some installations.

If the urea injection point is very far from the main tank, the installation of a transfer pump and of a day tankis needed to avoid cavitation. The transfer pump should be located close to the main tank, while the daytank should be placed in the engine room. The capacity of the urea day tank should be sufficient for 10hours operation at maximum urea solution consumption.

- Compressed air

Compressed air is required for urea injection and for the soot blowing system. The capacity of the com-pressed air should be calculated for proper and defined duration considering the maximum air consumption.

- Insulation

The insulation thickness should be in accordance with the applicable safety requirements, for instanceSOLAS (Safety Of Life at Sea). A thickness of 150 mm is usually recommended.

2.1.7 Service and maintenanceTable 2.6 gives a guideline for the calendar based maintenance schedule for the NOR system. The main-tenance intervals often depend on the operating conditions.

Table 2.5 Maintenance intervals

Maintenance neededUnitInterval

Checking the soot blower valve opera-tion

Soot blowing system1 month

Overhauling the pumpUrea pumping unit6 months

Maintaining the flow control valveDosing unit

Maintaining the atomization lanceUrea injection unit1 year

Cleaning and inspecting the catalystReactor

Lubricating the pump drivePump unit2 year or 5000 running hours

Lubricating the actuatorDosing unit3 years



3. SOx Emissions Control

3.1 The Wärtsilä Closed loop Scrubber

3.1.1 Fresh water SOx scrubberThe Wärtsilä Closed loop Scrubber is a fresh water and sodium hydroxide (NaOH) based closed loop exhaustgas scrubber, designed to remove SOx from the exhaust gas stream on ships.

Performance

As a default the scrubber system is designed for a maximum sulphur content in the fuel of 3.5%. The SOxreduction efficiency is 97,15%, corresponding to a reduction of fuel sulphur content from 3.5% to 0.1%.This is the typical guaranteed performance of the system.

Fuel with higher sulphur content can be used under certain conditions (e.g. low load operation or lowercleaning efficiency demand). In such cases the cleaning efficiency to a level of 0.1% sulphur level is notguaranteed at design conditions.

Rules and regulations

The system is certified in accordance with IMO Resolution MEPC.184(59), Guidelines for Exhaust GasCleaning Systems, adopted in July 2009.

Scrubber design criteria can be agreed upon on a project specific basis, and may include permitted SOx-emissions equivalent to 0.1% sulphur in the fuel as per:

• EU regulations for EU ports 1.1.2010.

• IMO regulations for SOx Emission Control Areas, with entry into force 2015, adopted in October 2008.

Configurations

The Wärtsilä Closed loop Scrubber is available in two different configurations:

• Main stream scrubber

• Integrated scrubber

The main stream scrubber is designed to be installed in the main exhaust gas stream of an individualdiesel engine. The solution is advantageous for a range of machinery configurations, for example singlemain engines, with generator engines and oil-fired boilers using low sulphur fuel. Also generator enginescan be equipped with main stream scrubbers. Main stream scrubbers can be fitted to both newbuildingsand retrofit installations.

The Integrated scrubber is designed to clean the exhaust gases of several main and auxiliary engines andoil-fired boilers onboard with one scrubber unit. Another benefit is that it does not increase the exhaust gasback pressure, making it particularly suitable for oil-fired boilers.

The Integrated scrubber is suitable for all ship types, and in particular ships with high fuel consumption inEU ports, such as cruise ships and tankers (especially during cargo discharge). The integrated scrubberconfiguration is available for both newbuildings and retrofit installations.

The basic process principle is similar for both main stream and integrated scrubbers. When comparingsub-systems, the main difference can be found in the exhaust gas system as the integrated scrubber isequipped with a fan arrangement after the scrubber. The scrubber process for both the Main streamscrubber and the Integrated scrubber is shown in the following system diagram. Each sub-system is alsodiscussed in more detail under dedicated chapters in this product guide.


Wärtsilä Environmental Product Guide3. SOx Emissions Control

Figure 3.1 Scrubber system diagram



System main components

Alkali feed pump15P03SOx scrubber unit15N01

Transfer pump15P04Droplet separator15N02

Exhaust gas fan15P06Alkali feed module15N04

Heat exchanger15E01Bleed-off treatment unit15N05

Wet sump15T01Effluent monitoring module15N06

Buffer tank15T02CEMS15N07

Alkali storage tank15T04Scrubbing water pump module15N11

Bleed-off distribution pipe15T06Scrubbing water pump15P01

Sea water pump15P02

Pipe lines

Alkali ventN2Exhaust gas, hotX1-Xn

Alkali suctionN3Exhaust gas by-pass, hotY1-Yn

Alkali feedN4Exhaust gas manifold, hotG1

Alkali to 15N05N5Exhaust gas, coldC1-C3

Fresh water to topping upT1Scrubbing waterS1-S3

Fresh water to 15N05T2SeawaterW1-W2

Fresh water to 15N02 washT3Bleed-off /DrainB1

EffluentE1-E3, E5Bleed-off from buffer tankB2

VentE4Overflow from scrubberB3

OverflowE5DrainB4

SludgeL1Bleed-off to 15N05B5

Compressed airR1Alkali fillN1

Materials

Pipes: 90 /10 CuNi / ship standardValves: Rubber lined butterfly, bronze discDesign pressure: 10 bar

SEAWATER LINES

Pipes: PPH / GRP / Alloy steel (as in scrubber)Valves: Rubber liner butterfly, s/s discDesign pressure: 10 barDesign temperature: 65°CGaskets and seals: EPDM

SCRUBBING WATER, BLEED-OFF, EFFLUENT

Pipes: AISI 316L Precision SteelValves: Ball or screw down, s/s body & insertDesign pressure: 10 barDesign temperature: 50°C (to be kept >20°C)

ALKALI (50% NaOH SOLUTION)

Pipes: Copper / ship standardValves: Ball, bronze body and insertsDesign pressure: 10 bar

FRESH WATER

Pipes G1, X1-Xn: Black steelPipes C1-C3: Alloy steel (as in scrubber)HEAT INSULATION:For lines G1, X1-Xn as required

EXHAUST GAS



Scrubber unit dimensions

The scrubber dimensions depend on the capacity and desired SOx reduction. Typically the scrubber unitis in one piece with the exhaust gas inlet connection radially from the side above the wet sump and theoutlet from top of the scrubber.

The scrubber module is built in a frame when the scrubber is installed on an open deck area. If the scrubberis installed in the engine casing, it can be without a frame but equipped with mounting brackets andmounting elements.

The scrubber weight is affected by material selection.

Combustion units

The combustion units can be diesel engines of any make, type or application, 2-stroke or 4-stroke.

Combustion unit gas flow and temperature throughout the load range are needed to determine the appro-priate scrubber configuration. Also permitted exhaust gas back pressure is needed.

3.1.2 Main stream scrubber

Description

Main stream scrubbers are usually located in the engine casing or funnel, in the direction of flow after otherexhaust gas components. The gas inlet is radial, and the outlet vertically from the top. The scrubber isequipped with a wet sump. The cleaned exhaust gases pass through a droplet separator before enteringthe stack.The scrubber unit should always be installed in a vertical direction. Horizontal positioning is notpossible as the efficient exhaust gas cleaning requires countercurrent interaction between the exhaust gasand scrubbing water.

Traditional exhaust pipes work as by-pass pipes. During normal operation the by-pass pipes are closed,preventing any escape of un-cleaned gases. When the scrubber is not in operation, the by-pass pipespermit by-passing of the scrubber.

In the process, the scrubbing water is pumped from the wet sump through the seawater heat exchangerto the top part of the scrubber. Scrubbing water is sprayed into the exhaust gas flow from the spray nozzlesin the scrubber. Water is also supplied to the mid part of the scrubber to further improve the SOx removalefficiency.

Scrubbing water passes through the packing bed and is collected and removed through the bottom. Thewater absorbs SOx emissions, heat and other components from the exhaust gas stream. The heat is removedin the seawater heat exchanger. The pH of the scrubbing water and thus the cleaning efficiency, is automat-ically monitored and controlled by alkali dosing.

As the overall dimensions of the scrubber, together with space for the auxiliary equipment and maintenance,exceed conventional engine casing dimensions, a slightly larger casing area may be required. It is importantthat the scrubber system is considered already in the project design phase in order to provide an efficientscrubber system together with optimized space utilization.

The scrubber section is exposed to the corrosive effects of the low temperature exhaust gases and is thusentirely built of highly corrosion resistant materials.

Exhaust gas pressure loss

The exhaust gas pressure loss over the scrubber at full gas flow is typically 900 Pa. In most cases such apressure loss is possible to accommodate within the permitted back pressure of the diesel engine, butshould be checked.

Noise attenuation

Normal exhaust gas silencers for diesel engines are located in the engine casing before the scrubber.

Operation

The scrubber is designed for continuous operation at full specified gas flow and SOx-reduction.



The main stream scrubber cannot be operated dry (without scrubbing water circulation). The scrubbershould be by-passed when not in operation. In such cases compliance with the regulations is to be achievedby using fuel with an appropriate sulphur content.

3.1.3 Integrated scrubber

Description

The scrubber system is integrated and arranged to clean the exhaust gases of several diesel engines andoil-fired boilers onboard. Suction branches with control and shut-off valves from exhaust gas and flue gaspipes are connected to a common manifold which is connected to the scrubber.

Traditional exhaust pipes work as by-pass pipes. During normal operation the by-pass pipes are closed,preventing any escape of un-cleaned gases. When the scrubber is not in operation, the by-pass pipespermit by-passing of the scrubber.

It is preferred that the exhaust gas inlet to the scrubber unit is longitudinally from aft or the bow of the ship.Such an arrangement will reduce the height of the unit equipped with wet sump as less margin is neededagainst inclination in longitudinal direction than transversal. The scrubber system is designed to operate inmaximum static and dynamic inclinations set by classification societies.

The hot exhaust gas piping before the scrubber can be designed with normal diameters and flow velocities,including the 3-way valves. However, just before the scrubber inlet an expansion piece is needed to increasethe diameter to correspond to a flow velocity of maximum 25 m/s at full power.

In most cases one Integrated scrubber per ship is the most practical and economical solution. However,a configuration consisting of two integrated scrubbers may be preferred for ships with two funnels locatedsome distance from each other. The Integrated scrubber is suitable for all ship types, and in particular shipswith high fuel consumption in EU ports, such as cruise ships and tankers (especially during cargo discharge).

The gas inlet is arranged radially in the lower part. An integrated scrubber has a wet sump, and a separateprocess tank is not needed. A wet sump minimizes the needed vertical lifting height and therefore the powerdemand of the circulation pumps.

An ideal location for an Integrated scrubber, serving several combustion units, is aft of or within the funnelenclosure. This arrangement gives a minimum loss of useable cargo or accommodation space with afunctional gas flow and access to main components. The rest of the exhaust systems and casing followconventional design with silencers installed before the scrubber intake.

Due to the high and exposed scrubber location on the upper superstructure the vessel profile may be af-fected, thus where aesthetic values are important, the scrubber is to be part of the vessels architecturaldesign already in the basic design phase. Early design also allows structurally continuous supportingbetween the scrubber and hull. Although the scrubber system is designed with a minimum of weight, dueto its high vertical center of gravity it is to be considered in ship stability calculations.

Fans

In the Integrated scrubber concept two frequency controlled suction fans are arranged to suck the exhaustgases. Fans at the scrubber outlet maintain a small but constant under pressure in the scrubber and suctionbranches. The fans are located in the clean exhaust gas flow after the scrubber unit. For each installationthe most feasible fan configuration will be selected, taking into account reliability issues, redundancy, safety,space limitations, noise as well as simplicity.

The fans are built in a module, which is typically intended for mounting on top of or next to the scrubbermodule top. Fan materials are selected to correspond to the demands of temperature and gas conditionafter the scrubber. The fan capacity is automatically controlled by the scrubber control system to minimizepower demand under all load conditions.

Valves

Automatically controlled exhaust gas dampers are installed for all relevant suction branches. The dampersare automatically controlled by the control system to enable the fan to operate at minimum power, andshut-off the gas flow to the scrubber if triggered by the safety functions embedded in the control system.

Shut-off valves are provided before the fans to enable, for instance, maintenance of one fan while the othercontinues to operate.



Exhaust gas pressure loss

The Integrated scrubber system does not increase the exhaust gas back pressure, making it particularlysuitable also for oil-fired boilers and all diesel engines. This is due to the use of suction fans. The exhaustgas pressure loss over the scrubber at full gas flow is optimized to obtain a suitable trade-off betweenscrubber physical dimensions and power demand of the fans.

The exhaust gas back pressure of the diesel engine and oil-fired boilers is about the same with the scrubberin operation or by-passed.

Noise attenuation

Normal exhaust gas silencers for diesel engines are located in the engine casing. The noise insulation ofthe exhaust gas enclosure is based on noise characteristics of the selected fan configuration and customerrequirements.

Interconnecting of exhaust gas pipes

In the Integrated scrubber the exhaust gas pipes from diesel engines and flue gas pipes from oil-firedboilers can be interconnected under the following conditions:

• Back-flow of hot, dirty gases into a standing engine or boiler shall be prevented in a reliable manner.A shut-off valve in combination with continuous pressure conditions preventing any such back-flowin case of a leaking valve is acceptable.

• Inadvertent choking of an engine or boiler in question shall be prevented in a reliable manner. A by-pass pipe designed to permit full aspiration of an engine or boiler in case shut-off valves are closedis acceptable.

In newbuilding ships Safe Return to Port (SRTP) regulation requirements can be fulfilled with one integratedscrubber unit. For vessels with several engine casings adjacent to each other the following arrangement isproposed:

• Exhaust pipes from different fire zones are routed purely through their own engine casings up to thefunnel, avoiding exhaust gas pipe penetrations through main fire bulkheads.

• The funnel is above the top of the fire zones, separated from the engine casing with A60 fire insulationand remote controlled fire flaps.

• The funnel area can be common for several engine casings and the scrubber unit located in funnel.

• One Integrated Scrubber cleaning the exhaust gases from all exhaust pipes from the engine casings.

Operation

Operation is similar to a main stream scrubber, but with certain consideration to the machinery´s operationalprofile. It may not be necessary to dimension the integrated scrubber according to installed machinerypower. Such dimensioning may result in unnecessary over-dimensioning as the installed power is not op-erated in practice. In order to dimension the integrated scrubber system properly it is relevant to identifythe maximum propulsion and electrical power as well as the ship´s heat demand.

In the case of an integrated scrubber the maximum exhaust gas flow is designed to cover all relevant oper-ating modes, including as an example:

• Sea going: Main engine(s) at 100% MCR + generator engine(s) load, (unless shaft generator(s) areexpected to be used in this operating mode). Oil-fired boilers are expected not to be in operation asexhaust gas boilers are providing the necessary steam.

• Sea going (Diesel-Electric machinery): Generator engines providing full propulsion and hotel power.Oil-fired boilers are expected not to be in operation as exhaust gas boilers are providing the necessarysteam.

• In port: Diesel-generator(s) and oil-fired boiler(s), as appropriate, at highest possible relevant load.

In most cases the sea going conditions result in the highest possible gas flow to be used as design criteria.The design conditions for integrated scrubber should be reviewed case by case for accurate dimensioning.



The integrated scrubber cannot be operated dry (without scrubbing water circulation). However, thescrubber can be by-passed by closing the exhaust branches to the scrubber. In such cases compliancewith the regulations is to be achieved by using fuel with an appropriate sulphur content.

3.1.4 Fresh water systemFresh water topping-up is needed to compensate scrubbing water evaporation losses and extracted bleed-off. The needed topping-up water equals the humidity lost to the atmosphere plus the bleed-off, minus thewater content of the exhaust gas from the combustion units. The water content in the exhaust gas is typicallyaround 5% in diesel engines and clearly higher in oil-fired boilers. The water balance is determined on aproject specific basis.

Fresh water consumption depends somewhat on prevailing ambient conditions. Scrubbing water andconsequently also the seawater cooling temperature affect the fresh water consumption.

Also the exhaust gas temperature at the scrubber inlet has a clear impact, and therefore the Exhaust GasBoiler parameters are needed to determine the water consumption. An efficient Exhaust Gas Boiler reducesthe scrubber fresh water consumption as the exhaust gas temperature is lower and less scrubbing wateris evaporated in the scrubber.

The topping-up water chloride content has an effect on the required bleed-off rate and therefore also onthe consumption of topping-up water. The fresh water consumption is case dependent, but as estimation,0.2 m3/MWh can be used.

The topping-up water supply is connected to the scrubbing water wet sump or pump module. Fresh wateris also supplied to the droplet separator on top of the scrubber for periodical rinsing.

A non-return valve, and where necessary, a vacuum breaker should be installed in the fresh water line toprevent scrubbing water being returned to the ship’s fresh water system.

Water quality

For topping-up water, evaporated water and a good quality tap water (bunkered from port) are normallyrecommended. If a reverse osmosis process results in similar water quality as above (which may be thecase with 2-stage reverse osmosis plants), that can be used as well. The quality of untreated sea or rainwater is unsuitable topping-up water. Also grey water should not be used as topping-up water. Technicalwater and low chloride water are preferred to achieve low consumption.

On cruise ships clean effluent from a modern Advanced Wastewater Purification (AWP) system can alsobe used for topping-up. Typically the amount of AWP-water available is much higher than the demand forscrubber topping-up water so fresh water may not be needed for the scrubber at all. AWP effluent cantypically be used for the scrubber when its quality fulfils the Alaska and IMO requirements. However, thechloride content should be restricted to a maximum of 300 mg/l. UV disinfection should be installed for theAWP effluent supply line to the scrubber to ensure the elimination of any bacteria or viruses.

3.1.5 Seawater systemExhaust gas heat is transferred to the scrubbing water and is removed in the seawater heat exchanger.The purpose of the cooling is to minimize the water content in the cleaned exhaust gas after the scrubber,thereby minimizing plume opacity and fresh water consumption. The cooling has no effect on sulphur re-moval efficiency from the exhaust gases.

The system is typically designed for a maximum of 32°C seawater temperature. Alternatively, a differenttemperature can be specified if requested. In cold environments a minimum seawater temperature shouldbe ensured by a thermostatic valve and a recirculation line to avoid crystallization of the sulphates in thescrubbing water. A sufficient flow of seawater is needed to ensure cooling of the scrubbing water.

The location of the heat exchanger onboard the ship should be below the water line. The ideal locationminimizes the length of the sea and scrubbing water circuits onboard the ship. The location of the sea waterpump should also be below the water line.

There is typically one plate type heat exchanger and one sea water pump per scrubber system installed.



3.1.6 Alkali feed systemAlkali is automatically added to the scrubbing water circulation to maintain the process pH and consequentlythe SOx removal efficiency. Typically 50% NaOH (Sodium Hydroxide), also known as Caustic Soda or Lye,solution is used as alkali. In some cases 20% NaOH solution can be considered due to its low freezingpoint.

The main components of the alkali feed system are the alkali pump, alkali feed control and alkali storagetank. Fresh alkali is automatically fed to the process as required by process chemistry. The main input datafor the alkali feed control are the sulphur content of the fuel and engine load, which corresponds with suffi-cient accuracy to the amount of exhaust gas and sulphur for cleaning. The sulphur content of the fuel inuse is to be typed into the system by the operator based on e.g. the Bunker Delivery Note. However, themain control is automatically adjusted based on the measured pH of the washing solution to compensatefor possible variations and inaccuracies in the fuel sulphur data.

Caustic soda bunkering areas, tanks and sounding pipes, and the feed module should be provided withwarning signs to ensure that all crew members are aware of the risks involved in general and in particularwhen any maintenance or repairs are made. The warning sign to be used is the standard “corrosive 8” sign,with text “Sodium Hydroxide Solution” and “UN 1824” nearby. Additionally “NaOH Solution” and “CausticSoda Solution” texts can be included.

Safety showers (with shower and eye wash) should be arranged for relevant alkali handling areas, such asbunker stations and the alkali feed module area. Protective clothing and chemical goggles should beprovided for personnel taking care of the bunkering of alkali or personnel otherwise handling alkali. All loc-ations where alkali is handled are to be provided with good ventilation.

NaOH Consumption

Alkali consumption depends on the concentration of the solution, engine operating power, fuel sulphurcontent and desired SOx-reduction efficiency. The alkali supply is automatically controlled based on theseparameters.

The 50% NaOH consumption in weight is roughly 6… 15% of the diesel engine fuel oil consumption de-pending on the sulphur content and cleaning efficiency. Indication of the alkali consumption can be seenin the figure below. It also indicates the relations of the affecting parameters.

Figure 3.2 Typical NaOH Consumption



Storage

Onboard storage capacity is dictated by the following parameters: vessel autonomy, alkali consumptionand the vessel´s operation profile and -area.

It is recommended that two separate, preferably adjacent, structural tanks are provided for alkali. Thisconfiguration would allow continuous scrubber operation during the tank surveys, inspections and cleaning.When tank location and volume are outlined, a high density of 50% caustic soda solution and the marginagainst overfilling (15-20%) are to be considered.

The recommended cleaning interval for storage tanks is 4 years. A single tank configuration can be used,if operation and regulation compliance with low sulphur fuel is a possible and feasible alternative duringthe above mentioned periods. Due to the relatively high density of caustic soda a low center of gravity forstorages may be favorable regarding vessel stability.

There is generally no limitation to tank geometry. The tank bottom should preferably be sloped towards adrain pipe. The tank for 50% NaOH should be dimensioned for a specific density of 1.52 t/m3, includinghydrostatic static pressure to an air vent head above the bulkhead deck. The tank should be externally orinternally stiffened. The integrity of the storage tank and related air vents should be hydrostatically testedprior the tank coating. Air vents need to be arranged from the highest points designed according to rulesof the applicable classification society.

General shipbuilding steels can be used for the tank construction. In each case when tank constructioninvolves structural members special consideration by the classification society is required. The temperaturelimits should be respected as at temperatures above 49°C carbon steel is sensitive to stress corrosioncracking, also known as “caustic embrittlement”. If higher temperatures are expected, special measuresincluding weld stress relieving and use of alternative materials should be considered case by case.

Any part of tank or tank fittings which may come in contact with caustic soda should not contain the followingmetals or alloys: aluminum, magnesium, zinc, brass, and tantalum. Caustic soda corrodes these metalsand the reaction may generate flammable hydrogen gas. In particular, the reaction with aluminum is vigorous.Long term exposure to caustic soda can deteriorate materials containing silica e.g. glass. It is recommendedto check the supplier’s compatibility information regarding gaskets for manholes and flanged tank fittings.Typically PTFE or EPDM should be used. Viton is not suitable as gasket or sealing material.

Internal tank coating is recommended to avoid corrosion that may occur particularly on tank upper parts.Major suppliers have epoxy resins that are suitable for this purpose. The suppliers’ recommendation is tobe followed concerning intended use, surface preparation and application.

Storage tank heating

The 50% caustic soda solidifies at temperatures below 12°C and therefore the tank should preferably belocated so that it shares common boundaries with the engine room as far as possible. If the tank temperatureis expected to drop below 16°C additional heating should be provided. The recommended storage temper-ature is between 25 and 35°C. The corrosive properties of caustic soda are aggravated at temperaturesabove 49°C (when carbon steel is used) and thus caustic soda storage should not have common structureswith e.g. heated fuel oil service and settling tanks. Also other heat sources that may locally increase thetemperature inside the tank to exceed the before mentioned value (e.g. exhaust gas or steam pipes) shouldbe isolated from tank structures.

The heating requirement of the storage tank can be determined by calculating the heat transfer througheach tank boundary. The same heat transfer coefficients through the external tank walls that are typicallyused for heavy fuel oil are applicable. In some cases external tank insulation could be considered to reduceheat losses.

If heat losses from the tank are remarkable, heating with water circulation in carbon steel coils can be used.To avoid corrosion of the heating coil´s external surface, the inlet water temperature should remain below49°C. For example, returning LT cooling water can be utilized for heating and heating coils can be connectedin parallel to the central cooler. The central cooler pressure drop or a dedicated circulation pump can beused for induced circulation depending on the pressure drop in the tank heating system. Coils should beinstalled to an approximate height of 300 mm from the tank bottom and located so that a thermal agitationpattern will occur.

The heating coils should be positioned to provide heating particularly in the suction pipe area. Heating coildimensioning is based on the differential temperature (Δt) between the lower storage temperature (25°C)and the arithmetic mean temperature of the incoming / outgoing circulating water. The mean heat transfer



coefficient from water coils to caustic soda can be estimated at 60 W/(m2 x °C), if turbulent flow conditionscan be achieved.

An alternative heating method is to provide a separate caustic soda circulation through an external heatexchanger. Thus the heating media can be low pressure steam or high temp heat recovery water. In thesecases the appropriate heat exchanger material should be selected, for example nickel. If heat losses aremoderate, external electric heating can also be used. The heating elements are adhesive and attacheddirectly to the tank wall under the insulation. Also in these cases the specified heating elements should notexceed maximum surface temperatures.

Storage tank fittings and instruments

When anywhere in the alkali system (bunkering, transfer, feed) the lines are located below the alkali storagetank level, the storage tank should be equipped with a quick closing valve. The quick closing valve is eitherconnected to the emergency stop, or has its own activation button or lever.

The primary suction should be located approximately 100 mm from the storage tank bottom. Tanks shouldalso be provided with low suction for complete draining prior to maintenance. The diameter is accordingto the installation specific system diagram. Each connection below the maximum surface level should beprovided with safety quick closing valves.

The alkali tank filling line should be led below the minimum service level and should be provided with avacuum breaker hole at the upper end where an anti-syphoning effect may occur. The filling line is typicallyDN 80 and provided with a DIN 2633 flange at bunker station. Filling pipe material recommendation is AISI316L or black steel DIN 2448. Transport trucks are provided with several different connection types dependingon supplier and country. Adapters may be required.

The caustic soda storage tank should be provided with the following alarms:

• Temperature high (set point 45ºC, if provided with heating)

• Temperature low (set point 25ºC, if relevant)

• Level low (e.g. 30%)

• Level high (e.g. 85%)

The caustic soda storage tank should be provided with the following indications:

• Local level gauge (hydrostatic type with sensor isolating valve) Sight glasses are not recommended.

• Local temperature gauge (gauge with stainless steel pocket)

Each caustic soda storage tank should be provided with a standard 600 mm x 400 mm manhole.

Instead of a sounding pipe an approved type local hydrostatic level indicator can be used, note that thedevice need to be calibrated for caustic soda density. The relevant classification society’s rules concerningsounding requirements should be verified.

The alkali storage tank air and overflow piping is lead similary to that of normal air and overflow pipes (e.g.above bulkhead deck and overboard). To prevent spraying of alkali, the air pipe end should be protectedby a plate or similar means.



Alkali feed module

As a general indication, the alkali feed module should be located between the alkali storage tank and thescrubbing water circuit. To minimize the suction line length it is preferred that the location of the alkali feedmodule is near the storage tank.

Dimensioned for full scrubber load and applicable NaOH solutionCapacity: ..............................................

Chemical dosingType: .....................................................

1 – 5 kWMotor: ...................................................

SteelFrame: .................................................

120 – 200 kgDry weight: ...........................................

200 – 300 kgWeight in operation: .............................

900 mmLength: .................................................

550 mmWidth: ...................................................

1600 mmHeight: ..................................................

The alkali feed module shutdown is connected to the emergency stop. The module and if necessary, otheralkali system related components should be provided with drip trays. The drip tray drainage should be ar-ranged with one of the following alternatives:

• Automatic quick closing valve. Drip trays should be provided at the lowest point with a leak detectorthat automatically activates the alkali storage tank quick closing valve. Drip trays are to be of adequatecapacity to receive such leak quantity which may escape from the system prior to closing of the quickclosing valve, including the quantity in the supply pipe. The leak detection and quick closing systemare to be of the fail safe type. Such drip trays are without drainage.

• Automatic drainage to safe tank. Vertical conditions permitting, drain pipes from the drip trays areconducted freely flowing back to the alkali storage tank or any other suitable tank. Such drain pipesshould be of adequate size, and provided with heating where necessary to avoid stiffening of thecaustic soda.

Alkali specification

The typical commercial solution is 50% (weight). Characteristics of a 50% solution are:

• Density 1.52 t/m3

• Solidifies (“freezes”) at 12°C

• Should be kept above 20°C when pumped

• Boiling point ca. 145°C

• Transported typically at 20… 40°C

• pH 14

• In some cases 20% solution is interesting, as its freezing point is -30°C. For on deck storage on shipsoperating in cold environment this could be feasible.

The Wärtsilä scrubber system typically uses 50% NaOH solution as the neutralizing agent in the process.

The customer/operator should acquire the chemical according to the following specifications.

Sodium Hydroxide solution 50% (water solution)Technical name: ...................................

NaOH (aq)Chemical formula: ................................

1310-73-2Cas N:o ................................................

215-185-5Einecs N:o ............................................

Caustic Soda 50%, Lye 50%Additional trade name(s): .....................

45… 52%-weightSodium Hydroxide, NaOH ....................

< 0.1%-weight as NaClChloride (Cl) ..........................................



Safety aspects

• Colorless and odorless.

• Causes eye and skin burns: eye and safety showers needed at least in the bunkering area.

• Aspiration hazard: ventilation of gases has to be taken care of.

• No fire risk.

• May react with water producing heat and gases, thus affecting fire extinguishing strategies in NaOHstorage areas.

• Can produce flammable gases when reacting with some metals (e.g. aluminum in contact with NaOHproduces hydrogen).

• Liquid should be protected from atmospheric moisture to avoid absorption of carbon dioxide fromthe air: air pipes, etc. needs to be designed accordingly.

• Contact with aluminum, zinc, brass and tin to be avoided.

3.1.7 Scrubbing water systemThe exhaust gas scrubber is working on the closed-loop principle. The scrubbing water is circulated throughthe system. Only a small bleed-off is extracted from the loop and fresh water and alkali is added. The flowrate of scrubbing circulation is related to the actual dimensions of the scrubbing module and design per-formance of the system.

The scrubbing water is buffered in a wet sump for controlling the quality of the solution. The scrubbingwater is circulated with circulation pumps from the wet sump to scrubber spray nozzles on top of thescrubber. Part of the scrubbing water is also circulated via a cooling heat exchanger to reduce the scrubbingwater temperature.

Both main stream and integrated scrubbers have a wet sump at the bottom of the unit.

Scrubbing water pump

The location of the scrubbing water pumps is project specific, depending on the position of the coolingheat exchanger and the wet sump. Typically the scrubbing water pumps are built in a module, which is tobe located adjacent to the scrubber wet sump.

For both main stream and integrated scrubber systems, typically three pumps are specified (two running,one in stand-by).

8…18 m3/MWh per pumpCapacity:

CentrifugalType:

3.1.8 Bleed-off systemTo remove the accumulated impurities from the scrubbing water a small flow of bleed-off is extracted andled to the emulsion breaking water treatment unit. The bleed-off contains traces of oil and combustionproducts, and its pH is typically close to neutral. Clean effluent from the treatment unit is discharged over-board, or led to the effluent holding tank (if applicable) for a scheduled and periodical discharge. Effluentquality monitoring is arranged before the discharge.

The extracted bleed-off from the scrubbing water circulation can be led to a bleed-off buffer tank prior tothe treatment unit. A bleed-off buffer tank can be arranged to offer operational flexibility, permitting operationof the scrubber with the treatment unit out of operation and vice versa.

An effluent holding tank is useful in operational situations where overboard discharges are to be avoided.The volume of such a storage tank should be dimensioned according to the time the scrubber is to be op-erated in such conditions.

The bleed-off flow can be minimized if a minimum scrubbing water temperature can be ensured e.g. witha thermostatic valve. With a lower sulphur content in the fuel the minimum temperature can be reduced.The bleed-off flow is interrelated with topping up water flow and may be 0.1 m3/MWh or even below, butin some conditions clearly higher.



The amount of generated effluent is very close to the bleed-off flow, as oil and sludge separated in thetreatment unit is very compact with a low water content.

Bleed-off treatment unit

The bleed-off treatment unit fulfils the scrubber guideline requirements in IMO resolution MEPC.184(59). Itfeatures a complete emulsion breaking system suitable for treating the bleed-off from the exhaust gasscrubber system. The system overview of the treatment unit can be found in chapter 4.1.1 in this productguide.

2.5 m3/hCapacity: ..........................................................................

920 kgDry weight: ......................................................................

1870 kgWeight in operation: .........................................................

950 lTotal volume: ...................................................................

1740 mmLength: ..............................................................................

1100 mmWidth: ..............................................................................

1850 mmHeight: .............................................................................

5 kWInstalled power: ................................................................

6-8 barInstrument air: ..................................................................

6-8 barService air: ........................................................................

max 300 l/hWater consumption (flocculants preparing): ....................

Bleed-off feed pump

The bleed-off is fed to the treatment unit by a feed pump, which automatically sucks bleed-off from thewet sump, (or bleed-off buffer tank if applicable). The pump is controlled by the treatment unit controlsystem based on the level in the sump or tank. If the tank is more than 5 meters above the treatment unitand flow by gravity is ensured, the feed pump is not necessary.

Sludge

Impurities separated from the bleed-off form compact sludge in the treatment unit, with sludge productiondepending on the fuel oil quality. The amount of generated sludge is approximately 0.1… 0.4 kg/MWh.

Sludge generated in the scrubber process is similar to engine room sludge. The composition of the sludgeis mainly hydrocarbons, soot and metals. The amount of water is minimized in the treatment unit, while stillkeeping it pumpable.

The scrubber sludge can be stored in the same tank as other engine room sludge. Scrubber sludge is notpermitted to be incinerated onboard.

3.1.9 Control and monitoringThe scrubber system is equipped with an automation system for operation, monitoring and safety control.A dedicated scrubber control unit with display is provided. Field sensors and control valves are included.The control system has the following functions:

• Control and safety

• Monitoring and alarms

• Data logging with trending capability

• Data logging is tamper proof and in compliance with Marpol regulations. The data is recorded againstUTC (Coordinated Universal Time) and ships position by a Global Navigational Satellite System.

• Real-time process control

• Interface to bleed-off treatment and to emission and effluent monitoring

The scrubber control system consists of the following equipment:

• Main Control Module (MCM)



• Input/Output Module. I/O extension module (IOM)

• Local Display Unit (LDU) Human Machine Interface, which can communicate with the vessel IAS overModbus TCP if necessary.

Interfaces to vessel Integrated Automation System (IAS) include:

• General alarm

• External starting and stopping request

• Engine running and load (preferably fuel rack position)

The ideal location of the scrubber control unit is in the ship´s engine control room.

System alarms

The following safety related system alarms are provided (there are other measuring points, which are notrelated to the system safety; these are not listed here):

1. High/low scrubbing water level in the scrubber wet sump

2. High/low scrubbing water temperature

3. High exhaust gas temperature after the scrubber

4. High/low level in the alkali tank

5. High/low temperature in alkali tankAdditionally for plastic scrubbers there are also the following alarms:

6. High exhaust gas temperature before the scrubber

7. Low scrubbing water pressure before the scrubber.

8. Low scrubbing water pressure before the quench.These system alarms generate an alarm in the scrubber control system.

Emergency stop

The emergency stop is activated with a push button. One emergency stop button is included in the scrubbercontrol cabinet. Additional buttons should be installed adjacent to the alkali feed module and the scrubberunit in easily accessible locations. The emergency stop activates the scrubber shut-down sequence.

The emergency stop has the following functions:

• Stop of alkali feed pump

• Opening of the exhaust gas by-pass valve

• Stop of scrubbing water circulation pumps

• Stop of seawater cooling pump

• Closing of control valves

The alkali storage tank quick closing valve can be connected to the emergency stop function, or it can havea separate control.

The emergency stop button has to be manually deactivated before the system start-up sequence can bestarted.

In case of a ship blackout no special arrangements are required. The blackout stops the system, and afterblackout the system can be restarted normally. If a long black-out occurs in cold conditions, the risk of thealkali or scrubbing water temperature being too low needs to be considered.

Shutdowns

A system shutdown is similar to an emergency stop. The following signals cause immediate system shutdown:

1. High-high exhaust gas temperature after the scrubber

2. High-high level in the wet sump



Emissions monitoring

A continuous Emission Monitoring System (CEMS) is arranged to monitor the SO2 and CO2 content of theexhaust gases. NOx monitoring can be included as an option. The CEMS is connected to the scrubbercontrol system, and can be based on either an in-situ or extractive method.

The main components in the extractive CEMS are:

• Exhaust gas sampling probe. Located near the scrubber exhaust gas outlet.

• Heated sampling line.

• Main cabinet. Weight and dimensions: 200 kg, 600 x 650 x 1700 mm.

The ideal location of the CEMS cabinet is in the ship´s engine control room.

The main components of an in-situ CEMS are:

• Exhaust gas sampling probe. Located near the scrubber exhaust gas outlet.

• PC (in some cases)

Effluent monitoring

The effluent monitoring module continuously monitors the PAH, turbidity, pH and temperature from the ef-fluent according to regulations. The effluent monitoring is connected to the scrubber control system. Themain characteristics are:

• Monitoring module in the effluent line after the bleed-off treatment unit.

• Module weight and dimensions approx: 300 kg, L 810 x W 650 x H 1440 mm.

The system fulfils the IMO resolution MEPC.184(59) requirements for scrubber discharge water monitoring.

Reports to Administration or Port State authorities

The required data is recorded against UTC (Coordinated Universal Time) and ships position by a GlobalNavigational Satellite System. The system enables reporting over specified time periods. The recorded dataand reports can be downloaded in readily usable format to portable data storage with USB connection.

3.1.10 Power demandThe power demand of the Wärtsilä scrubber in normal conditions varies between 0.4... 0.6% of the enginepower. The power consumption is lower in colder sea water temperatures than in tropical conditions. Thepower demand of the Integrated scrubber increases towards top ship speeds to around maximum of 1%.

The total power of supplies connected to ancillary devices is somewhat higher, to allow for variations inambient and operating conditions, system tuning, selection of standard components and margins. Thanksto embedded frequency converters and control algorithms, the power demand is optimized at reducedpower and reduced sea water temperatures.

The total power consumption of the scrubber system will be determined depending on the final configurationand plant size.

3.1.11 MaintenanceMaintenance of the scrubber system comprises generic maintenance tasks of individual pieces of equipment(such as valves and actuators, pumps, electric motors, heat exchanger, tanks, etc.).

The scrubber unit is equipped with maintenance hatches for periodical inspection of the internals and spraynozzles. In normal operating conditions maintenance and service work to the scrubber unit is minimal.

Maintenance openings (hatches) with size DN600 flanges are provided in the scrubber unit as standard.Hatches are big enough for a service mechanic to climb in and transport tools and service equipment inand out of the scrubber. The droplet separator is inside the scrubber unit in pieces that are installed througha DN600 opening from above. Access to the droplet separator from above is also preferred as the elementsare inspected while walking/crawling on them.

A typical scrubber unit construction contains the following maintenance openings:

• One hatch above the droplet separator



• One hatch with visual view and possible access to each spraying nozzle stage

• One hatch above the bottom of the packing bed

• One hatch above the bottom of the scrubber

The radial direction is optional and it does not have to be the same for each hatch. Hatches at spray nozzlelevel can be omitted if visual view and access to the nozzles can be arranged via other maintenanceopenings; e.g. with scaffolds from below to lower stage spray nozzles or with a safety harness from dropletseparator level to upper stage spray nozzles. Spray nozzles are inspected visually from upper hatch whilespray is on (with no exhaust gas) and if the spray pattern is in condition, there is no need to actually climbto each nozzle.

Outside the scrubber, the access area to the hatches should be reasonable. A small platform of approximately1 m2 in front of each hatch should be available.

Detailed maintenance instructions are given in the operation and maintenance manual and they should befollowed in conjunction with general good housekeeping.

3.1.12 Exhaust gas system

Insulation

Scrubber unit thermal insulation is not necessary. The hot exhaust gas pipes before the scrubber are normallyinsulated as well as the by-pass pipes.

Plume enclosure

Engine room ventilation exhaust air from the engine casing can be conducted to an open-ended jacketsurrounding the exhaust gas outlet pipe in the funnel. Thus humid gas from the scrubber is mixed with dryair from the engine casing, reducing humidity and plume opacity. This is achieved by arranging the jacketas an enclosure with an upper end clearly above the end of the stack.

Exhaust gas pipes

All parts of the exhaust gas system before and after the scrubber are optimized concerning pressure lossesto maintain an acceptable exhaust gas back pressure at the engine outlet.

To avoid droplet entrainment with the gas flow, the flow velocity after the scrubber should be kept low(preferably not exceeding 15 m/s at full power), welding seams should be smooth and knuckles avoided.

After the scrubber the exhaust gas has a high relative humidity. Corrosion resistant materials are recom-mended.

Thermal insulation of the exhaust gas pipes after the scrubber can be omitted. Hot uninsulated exhaustpipes can be used in the funnel area as on any ship, under the following conditions:

1. In the funnel, being an open area.

2. Not in the engine casing (being Category A Machinery Space).

3. Engine room ventilation exhaust air can be conducted through the area, provided that the engine casingcan be isolated from the funnel with fire dampers.

4. Insulation for noise absorption purposes can be installed in the area.

5. Any possible common boundary of funnel with interior spaces fulfill A-0 fire insulation standard as aminimum.

6. Pressurized fuel oil and lubricating oil pipes are not installed in the same area.

7. Danger to persons onboard due to hot surfaces is minimized.



4. Bilge Systems

4.1 Wärtsilä Oily Water Separator (OWS)

4.1.1 System overviewThe Wärtsilä OWS unit is an oily water separator used for bilge water treatment in marine installations. TheWärtsilä OWS separates oil and emulsions so that only treated clear water is discharged to the sea. Theguaranteed amount of oil in the water after the treatment process is less than 5 ppm. The Wärtsilä OWS iscertified according to USCG and the latest IMO regulations, where the max allowed oil content in the dis-charge water is 15 ppm at any time.

The Wärtsilä OWS main stages are:

- oil separation stage

- chemical mixing stage

- flotation stage

The unit is available in three different sizes and is built in modules for easy installation onboard ships.

Wärtsilä OWS units

PerformanceOil & Grease

Capacity [m3/h]Type

< 5 ppm0.5Wärtsilä OWS 500




Wärtsilä Environmental Product Guide4. Bilge Systems

Figure 4.1 Wärtsilä OWS 500 (66651056_00)

Wärtsilä OWS 500 main dimensions and weights

W [mm]L [mm]H [mm]Weight, full [kg]Weight, empty [kg]Type

76512301720775500Wärtsilä OWS 500

Pipe connections Wärtsilä OWS 500

DN 25InfluentA

DN 25EffluentB

DN 25To sludge tankP

DN 10Air inletR

VentilationW



Figure 4.2 Wärtsilä OWS 1000 (DAAE054487b)



1100234418551950650Wärtsilä OWS 1000


DN 25WaterQ

DN 25Drain/ OverflowG

DN 25EffluentB

DN 25InfluentA

DN 25To sludge tankP1

DN 25To solid packP2

DN 25To sludge tankP1/P2

DN 10Air inletR

VentilationW1

VentilationW2



Figure 4.3 Wärtsilä OWS 2500 (DAAE076426)



1400321018552700950Wärtsilä OWS 2500


DN 25WaterQ

DN 25Drain/ OverflowG

DN 25EffluentB

DN 25InfluentA

DN 25To sludge tankP1

DN 25To sludge tank or solid packP2

DN 10Air inletR

VentilationW1

VentilationW2



Process description

The Wärtsilä OWS treatment process is shown in the following diagram.

Figure 4.4 OWS process diagram

The first stage, known as the separation stage, is constructed for the separation of free oil from thewastewater. The water content in the separated oil depends on the quality of the oil. The oily emulsifiedwater is pumped from the oily water buffer tank to the oil separation tank by a feed pump. In the bottomof the separation tank dispersion water (pressurized water saturated with air) is added to the oily water.The dispersion water is made by circulating treated water and adding compressed air into it in a separatetank. As the dispersion water is released to the lower pressure in the tank, micro bubbles are formed. Inthe tank the bubbles rise and help the oil rise to the surface, from where it is skimmed to an internal oiltank. From the internal oil tank the oil is pumped to the sludge tank. The water is collected into an integratedtank for further treatment in the flotation stage.

From the oil separation stage the emulsified water is lead through a series of mixers. Treatment chemicalsare dosed with dosing pumps to the injection points on the mixers. The purpose of the chemical treatmentis to break the emulsified oil in the water into particles and to make them into larger flocks that are easilyseparable by means of the flotation.



After the mixers the water enters the flotation stage. Again the dispersion water is injected to the bottomof the flotation tank. The micro bubbles produced are mixed with the suspended material. Gas bubblesattach to the solids forming solids/gas flocks, which are lighter than water and therefore rise to the surfaceand form a floating layer. The layer is removed by scraping and guided into the solids collecting tank unit.From there it is pumped to the Solidpac, solids tank or sludge tank.

The clear water passes a series of baffles and a parallel flock trap to separate the smallest particles beforeit is pumped to an activated carbon filter unit to clarify the water further. Before the filter, a part of the wateris taken to be used as dispersion water in the dissolved air flotation. The water is discharged after the sandand/or activated carbon filter. The filter stage is included as standard delivery for Wärtsilä OWS 1000 and2500 types. The filter stage is not included in the Wärtsilä OWS 500 type.

The electric consumption of the Wärtsilä OWS unit is 10 kW.

Chemicals

The chemicals used in the oily water separator process are; a coagulant, a flocculant and caustic soda(NaOH). The coagulating chemical is used for breaking the emulsified oil in the water into particles whilethe flocculant will collect the particles into bigger flocks for easier separation. Caustic soda is used for pHcontrol. The unit is equipped with chemical storage and the consumption is 0.4 g/l of the coagulant, 0.4 g/lNaOH and 0.005 g/l of the flocculant. The flocculant is a powder that shall be mixed with water.

4.1.2 OptionsThe following options are available for the Wärtsilä OWS unit.

Solidpac

A Solidpac module can be installed after the treatment unit for de-watering the solid waste from the separ-ator. The Solidpac consists of a frame supporting two water-repellent filter sacks. 100 sacks with sealingwires are delivered as standard.

The Wärtsilä Bilge Water Guard

The Wärtsilä Bilge Water Guard is a bilge discharge monitoring system that constantly monitors and recordsthe quantity of water being discharged overboard. It also monitors oil content and the time and location ofthe vessel. Should the effluent, for any reason, contain a level of oil exceeding the set limit, the flow isrerouted to the sludge tank. The system provides both a safety net, and a means of documenting what andwhere discharges have been made. According to the latest IMO regulations, the max allowed oil contentin water is 15 ppm at any time.

The oily water enters the unit and a metering system measures the oil content. The information goes to acomputer located in the unit. Downstream, a three way valve is located which directs the bilge water backto a bilge tank if the oil content is higher than 15 ppm (or a set limit). Further downstream a flow meteringsystem measures the total effluent passing the Bilge Water Guard before it is discharged overboard. Allthis information is logged in the computer, including GPS position, ppm value and over board valve status.The Bilge Water Guard system can be connected to the ship´s automation system for easy surveillance.The Wärtsilä Bilge Water Guard has a capacity of max. 15 m3/h. The installed power is 0.6 kW and the airconsumption is less than 0.0001 Nm3/min at 0.7 MPa (7 bar). The amount of water required for backflushingis 10 litres per flushing.



5. Ballast Water Management

5.1 Wärtsilä AQUARIUS EC

5.1.1 System overviewWärtsilä AQUARIUS – EC is a modular ballast water management system, providing a safe, flexible andeconomical process for the treatment of ballast water. Ballast water treatment with a Wärtsilä AQUARIUSTM– EC system is achieved through a simple and efficient two stage process. Upon uptake the seawater isfirst passed through a back washing filter (1st Stage) and then the filtered seawater passes through a staticmixer, where the disinfectant generated from the side stream electrolysis unit (2nd stage) is injected to ensurea maximum level of 10ppm in the treated ballast water.

Figure 5.1 Aquarius EC dimensional drawing

Table 5.1 EC Filtration Module

Flange size(PN10)

Dry weight(kg)

Height (mm)Width (mm)Lenght (mm)Capacity(m3/h)

AQUARIUSModule

80460120075020000-50AQ-50-EC

1006301450750240050-80AQ-80-EC

1507601550800240080-125AQ-125-EC

15086017008002400125-180AQ-180-EC

200105016008002400180-250AQ-250-EC

200105020008002400250-300AQ-300-EC

2501500200011002700300-375AQ-375-EC

2501500200011002700375-430AQ-430-EC

300170020009003000430-500AQ-500-EC

300170020009003000500-550AQ-550-EC

3503100250013003700550-750AQ-750-EC

3503100250013003700750-850AQ-850-EC

3503200250013003800850-1000AQ-1000-EC

40035502700130039001000-1200AQ-1200-EC


Wärtsilä Environmental Product Guide5. Ballast Water Management

Capacities to 6000 m3/h achieved through a number of modular combinations.

Table 5.2 EC Treatment Module

Flange size(PN10)

Installed/NominalPower (kW)

Dry weight(kg)


AQUARIUSModule

8015.9/10.815752300215024000-125AQ-50-EC

10015.9/10.815752300215024000-125AQ-80-EC

15015.9/10.815752300215024000-125AQ-125-EC

15030.8/21.61575230021502400125-250AQ-180-EC

20030.8/21.61575230021502400125-250AQ-250-EC

20046.2/32.41765230021502800250-375AQ-300-EC

25046.2/32.41765230021502800250-375AQ-375-EC

25060.6/43.21810230024503200375-500AQ-430-EC

30060.6/43.21810230024503200375-500AQ-500-EC

30090.4/64.81960230024503200500-750AQ-550-EC

35090.4/64.81960230024503200500-750AQ-750-EC

350120.2/86.42125230034004100750-1000AQ-850-EC

350120.2/86.42125230034004100750-1000AQ-1000-EC

400177.8/129.622502300340041001000-1500AQ-1200-EC

Table 5.3 EC Power Panel

Weight (kg)Height (mm)Width (mm)Lenght (mm)AQUARIUS Module

5001500750900AQ-50-EC

5001500750900AQ-80-EC

5001500750900AQ-125-EC

5001500750900AQ-180-EC

5001500750900AQ-250-EC

6501500950900AQ-300-EC

6501500950900AQ-375-EC

6501500950900AQ-430-EC

6501500950900AQ-500-EC

130022001140940AQ-550-EC

130022001140940AQ-750-EC

130022001140940AQ-850-EC

130022001140940AQ-1000-EC

195022001710940AQ-1200-EC



5.1.2 Operating principle

Filtration

During uptake ballast water passes through an automatic back washing filter. The filter removes particulates,sediments, zooplankton and phytoplankton over 40 microns. Automatic filter cleaning ensures and maintainsfiltration efficiency.

Electrochlorination

Disinfectant TRO (Total Residual Oxidant) is produced by an electrolysis module, comprising of electrolyticcells, specifically designed to generate sodium hypochlorite from seawater.

The sodium hypochlorite generated is pumped into the main ballast line, where it is mixed with filteredballast water for efficient disinfection, and pumped into the ballast tanks. Ballast Water TRO concentrationis monitored to ensure the correct hypochlorite dose.

During discharge the filter is bypassed and residual concentration of TRO in treated ballast water is monitoredbefore being discharged overboard.

If required, treated ballast water is neutralized by injecting sodium bisulfate into the main ballast line duringdischarge. Neutralization effectiveness is continuously monitored to ensure compliance with MARPOLdischarge limits.

Standard features

• Broad environmental operating envelope

• Flexible side stream electrolysis configuration with no salinity limits and no temperature limits

• In situ safe, sustainable and economical disinfectant generation

• Efficient injection and dosing controls

• Modular construction for efficient use of space and power, and easy integration with ship systems

• Flexible up scaling

• Intelligent PLC control ensuring safe, automatic and economical operation



5.2 Wärtsilä AQUARIUS UV

5.2.1 System overviewWärtsilä AQUARIUSTM – UV is a modular ballast water management system, providing a safe, flexible andeconomical process for the treatment of ballast water. Ballast water treatment with the Wärtsilä AQUARIUSTM– UV system is achieved through a simple and efficient two stage process. Upon uptake the sea water isfirst passed through a back washing filter (1st Stage). The filtered sea water then passes through a UVchamber (2nd stage) where ultra-violet light is used to disinfect the water prior to entering the ballast tank.Upon discharge, water from the ballast tanks passes through the UV chamber only for a second time.

Figure 5.2 Aquarius UV dimensional drawing

Table 5.4 UV Filtration Module

Flange size(PN10)

Dry weight(kg)


AQUARIUSModule

80460120075020000-50AQ-50-UV

1006301450750240050-80AQ-80-UV

1507601550800240080-125AQ-125-UV

15086017008002400125-180AQ-180-UV

200105016008002400180-250AQ-250-UV

200105020008002400250-300AQ-300-UV

2501500200011002700300-375AQ-375-UV

2501500200011002700375-430AQ-430-UV

300170021009003000430-500AQ-500-UV

300170021009003000500-550AQ-550-UV

3503100250013003700550-750AQ-750-UV

3503100250013003700750-850AQ-850-UV

3503200250013003800850-1000AQ-1000-UV

Capacities to 6000 m3/h achieved through a number of modular combinations.



Table 5.5 UV Treatment Module

Flange size(PN10)

Dry weight(kg)

Lamp Power(kW)

Height (mm)Width (mm)Lenght (mm)AQUARIUSModule

15027513.27008501600AQ-50-UV

15027513.27008501600AQ-80-UV

15027513.27008501600AQ-125-UV

20045030.680010002200AQ-180-UV

20045030.680010002200AQ-250-UV

20055037.780010002500AQ-300-UV

25055039.680010002500AQ-375-UV

25055043.280010002500AQ-430-UV

30055055.380010002500AQ-500-UV

35075070.090011502600AQ-550-UV*

35075087.590011502600AQ-750-UV*

35075087.590011502600AQ-850-UV*

35075087.590011502600AQ-1000-UV*

*Two UV power panels are supplied per system

Table 5.6 UV Power Panel

Weight (kg)Height (mm)Width (mm)Lenght (mm)AQUARIUS Module

20012004001200AQ-50-UV

20012004001200AQ-80-UV

20012004001200AQ-125-UV

35017004001200AQ-180-UV

35017004001200AQ-250-UV

35017004001200AQ-300-UV

45019004001200AQ-375-UV

45019004001200AQ-430-UV

45019004001200AQ-500-UV

45019004001200AQ-550-UV

75019004001200AQ-750-UV

75019004001200AQ-850-UV

75019004001200AQ-1000-UV



5.2.2 Operating principle

Filtration

During uptake ballast water passes through an automatic back washing filter. The filter removes particulates,sediments, zooplankton and phytoplankton over 40 microns. Automatic filter cleaning ensures and maintainsfiltration efficiency.

UV treatment

Filtered ballast water is directed into a disinfection chamber where ultraviolet lamps, set up in cross flowarrangement, deliver UV irradiation to achieve disinfection. Treated ballast water is then directed to theballast tanks.

Lamps are fitted with an automatic wiper system which prevents bio-fouling and controls the accumulationof deposits on lamp sleeves ensuring maximum performance at all times.

UV light intensity is continuously monitored during system operation to ensure intensity is maintained andthe desired dose for maximum treatment efficiency is achieved.

During discharge ballast water is pumped from the ballast tanks back through the UV disinfection chamberfor final treatment before being discharged overboard. The filter is bypassed during discharge.

Standard features

• Broad environmental operating envelope

• No minimum retention time

• No active substances

• Integrated antifouling control system (No CIP)

• Modular construction for efficient use of space and power, and easy integration with ship systems

• Flexible up-scaling

• Intelligent PLC control ensuring safe, automatic and economical operation



5.3 Wärtsilä Ballast Water Treatment System (BWTS)

5.3.1 Integrated Filter, UV SystemThe Wärtsilä BWTS is fully integrated and specifically designed for the marine environment. Wärtsilä offersa full suite of product models covering a complete range of flow rates in a compact design for individualinstallation or optimized manifold configurations. This allows Wärtsilä to address all applications and marketsegments (new build and retrofit) and vessel types. In addition, Ex certified systems are available for alldiscrete flow ranges in the product suite.

The system is unique in that it combines two purely physical treatment processes; mesh filtration at 30microns, and UV disinfection in one single unit. This reduces the need for complex interconnecting pipingand the associated pressure loss. The small footprint of the integrated system, along with the option toconfigure the system vertically or horizontally, increases flexibility in locating the system within the vessel.

The ballast water treatment system utilizes the state-of-the-art SOLO Lamp from Trojan Technologies whichcombines high electrical efficiency and high germicidal light output. Because of the lower power requirements,there is less likelihood of needing an additional generator set which saves on capital cost, footprint (requiredfor the generator set) and fuel consumption. Whenever possible, it is ideal to fit into the existing power in-frastructure, which is much more likely with our lower power requirements – for example, our 500 m3/hsystem requires one-half to one-third the power compared to a similar flow capacity system offered byother filtration and UV ballast water treatment systems.

Wartsila designed the ballast water treatment system with enhanced operability as a primary design para-meter. Interruptions and delays in ballast water treatment result in increased time required for cargo oper-ations which have a financial impact. In addition, if there is an increased risk of non-compliance, then thereis a higher potential for fines from port state control. Wärtsilä utilizes the same core treatment elements(same UV lamp and filter elements) across its product suite and only varies the number of filter elementsand lamps to address different discrete flows. This provides a distinct advantage to customers as commonspares may be used across all vessels in their fleet.

Wärtsilä has specifically designed a filter with increased surface area. The filter consistently removes organ-isms; consistently and consecutively passing testing requirements. With the increased surface area the filteris able to operate at a lower flux rate. The lower flux rate coupled with an optimized backwash drain systemallows the pressure trigger for the automatic backwash to be lower while maintaining the proper differentialfor optimal cleaning of the filter element. In addition, the lower flux rate puts less stress on the filter ensuringit operates properly.

The operation of the system can be fully automated. The treatment inlet valve is opened, during this timethe lamps are activated. The filling and lamp initiation sequence is completed simultaneously. The lampwiper initiates a cleaning cycle during the filling operation. Once the system is completely full, the outletvalve is opened and the treatment process starts. The system control works together with the flow trans-mitter and the pump. Filtration is the first step in the process removing particles and larger organisms, whileevenly distributing the flow of the ballast water into the UV section of the treatment housing. The secondstep of the process occurs during deballast. Water is moved from the ballast tank to the de-ballast inlet ofthe treatment unit. During the second stage process, the ballast water flows through the UV section of thetreatment unit and is then discharged overboard.

Table 5.7 Wärtsilä BWTS portfolio

WeightWet (kg)

Weight Dry(kg)

PressureDrop OverSystem(clean)

PowerConsump-tion (kW)

Height (m)Width (m)Length (m)TreatmentCapacity

WärtsiläBWT Sys-tem

165011500.1 bar10.702.401.200.65150 m3/hBWT 150i

265018000.1 bar13.402.600.900.90250 m3/hBWT 250i

266820000.1 bar26.502.021.401.00500 m3/hBWT 500i

28500.1 bar36.002.601.401.20750 m3/hBWT 750i

38000.1 bar44.002.601.401.301000 m3/hBWT 1000i

725048000.1 bar61.702.601.702.381250 m3/hBWT 1250i

57000.1 bar67.002.602.002.431500 m3/hBWT 1500i



5.3.2 Regulatory RequirementsThe Wärtsilä Ballast Water Treatment System has been developed to comply with the Ballast Water require-ments from both the IMO and the USCG.

Type approval

Testing is currently being completed to the US ETV protocols which meet the IMO requirements for typeapproval. In addition, testing to ETV protocols provides the best strategy to meet US regulations and obtainUS type approval. IMO type approved is expected in 2012. All ballast water treatment systems providedby Wärtsilä are guaranteed to have IMO type approval.

5.3.3 Wärtsilä BWTS general descriptionThe Wärtsilä ballast water treatment system is specifically designed for the marine environment and combinesfiltration and Ultraviolet disinfection into one physical unit. The integrated design not only provides a compactfootprint but also reduces the interconnecting piping and pressure requirement. The system is fully automatedfor operations, including filter backwash and lamp cleaning.

Automatic Operation

The ballast water treatment system is fully automated. The treatment process starts automatically whenthe system control receives a corresponding signal from the flow transmitter together with running signalfrom the pump. Water flows into the unit and filtration is used to remove particles and organisms. In addition,this evenly distributes the flow of the ballast water into the ultraviolet disinfection section of the housing,optimizing hydraulics which ensures proper exposure to the ultraviolet lamps for the most efficient disinfectiontreatment before it exits the system and flows to the ballast tank.

Ballasting

Water is pumped into the Ballast Inlet (Ballasting) at the top of the treatment unit. The water flows firstthrough the filter elements, where debris and larger organisms are removed. Once a pre-set pressure dif-ferential is met, an automatic on-line back flushing cycle removes debris trapped on the filter elements,and directs it back to the original source water through the backwash outlet. Water passes through the filterelements and then flows through the ultraviolet disinfection treatment zone within the unit. The treatedwater is then directed to the ballast water pipe through the Ballast Water Outlet.

De-ballasting

Upon de-ballasting, water is sent directly to the ultraviolet disinfection treatment zone, and bypasses thefiltration portion of the unit. Ballast water enters through the Ballast Water Inlet (de-ballasting) on the frontof the unit. Water is directed through the ultraviolet disinfection treatment zone for a second application ofultraviolet treatment, and then directed back to the ballast water pipe for discharge through the BallastWater Outlet.

Filling

The ballast inlet or de-ballast inlet are opened to allow water to be pumped into the treatment unit. Duringthis time all lamps are turned on and a wiping sequence is initiated. All other valves remain closed until thetreatment unit is full and the lamps wiping sequence is complete. Depending on the installation type, afilling sequence lasts five (5) minutes. When the system is full the outlet valve is opened and moving ballastwater can begin.

Note: The system can remain on with all valves closed up to fifteen (15) minutes without needing to exchangewater.

Automatic Filter Backwash System

The ballast water treatment system is equipped with an automatic filter backwashing system that automat-ically initiates a cleaning sequence based on differential pressure across the filtration system. The systemhas two pressure sensors, one located on the ballast water inlet and the other on the ballast water outlet.These pressure sensors provide a signal to the control panel to initiate a backwash sequence. The backwashsequence consists of opening an actuated backwash valve and signaling the filter drive motor to make one



revolution. Each revolution of the drive motor allows each filter element to reverse its flow allowing accumu-lated debris trapped by the filter to be carried out to drain.

During backwash, a flow meter is used in conjunction with a regulating valve to maintain consistent flowrate through the treatment housing. Even when treating backwash water, the flow valve is adjusted tomaintain the correct amount of process water into the ballast tanks. This ensures the designated flow rateof the system is always achieved when the ballast water pump has been sized properly.

As each individual filter element is being backwashed, the remaining filter elements continue to processwater. Once the filter drive motor has completed its revolution, the backwash valve closes, completing thecleaning sequence. The automatic filter backwash system ensures that the ballast water treatment systemremains operable in the most difficult water quality conditions.

Automatic Lamp Cleaning System

The ballast water treatment system is equipped with a lamp cleaning system that automatically initiates acleaning sequence at the beginning and end of a ballasting cycle. The ultraviolet lamps incorporated in allultraviolet disinfection systems are housed in quartz sleeves. These quartz sleeves will become fouled overtime and this reduces the amount of ultraviolet light available for treatment. The lamp cleaning system re-moves any fouling that could build up on the lamp sleeves and reduces the need for maintenance. To ensureflexibility in operation, the lamp cleaning sequence can also be initiated during operation or on a timed se-quence. This is a benefit compared to systems that utilize chemical cleaning as these systems must betaken off line to inject the cleaning chemical. As a result, for chemical systems, it is necessary to wait untilballast or de-ballast operations are completed before cleaning can occur.

The automatic lamp cleaning system is sequentially driven. Each lamp wiping mechanism consists of awiper plate, wiping seals and one hydraulic actuator. The hydraulic actuator moves the wiper plate withwiping seals from one end of the lamp sleeve to the other. A cleaning sequence consists of actuating thelamp cleaning system from its home position to the end of the lamp sleeves and back to the home position.The cleaning cycle is finished when the last lamp wiping mechanism reaches its home position. The auto-matic lamp cleaning system ensures that the ballast water treatment system remains operable duringlengthy ballasting operations. The actuator is 100% sealed from marine contaminants. The sealed cylindermoves a magnet up and down the shaft which in turn moves a sealed coupling on the shaft that is connectedto the wiping plate.

Ultraviolet Intensity Sensor

The ballast water treatment system is equipped with a DVGW approved UV intensity sensor to monitor theultraviolet output of the lamps. DVGW is one of the world’s leading institutes for setting standards for theuse of Ultraviolet disinfection for the treatment of drinking water. In the event of low ultraviolet output, analarm condition is initiated to warn of the potential for insufficient treatment.

Options

The following options are available for the Wärtsilä BWTS:

• Ex certification for all discrete flow models

• Vertical configuration

• Horizontal configuration

• Multiple systems in a manifold configuration

• Inlet and outlet flange pieces are removable for added installation and shipping flexibility



6. Crankcase Vent Systems

6.1 Oil Mist Separator ModuleBecause the combustion chamber cannot be completely sealed, a small part of the gas escapes as “blow-by” via the piston/cylinder liner gap and the piston rings into the crankcase. In turbo-charged engines thereis also blow-by gas coming through the shaft sealing in the turbocharger. Since the crankcase is not designedfor high pressures it requires a ventilation pipe to prevent pressure from building up inside.

Because the gas pressure is very high during piston blow-by it violently tears the lube oil off the wallsbreaking it into very small oil droplets forming a fine oil mist gas. These small oil droplets escape thecrankcase via the crankcase ventilation which leads to oil pollution in the close surroundings and to increasedlube oil consumption. By installing an oil mist separator module, the crankcase gas can be cleaned of oildroplets. However, the emissions from the crankcase ventilation are very low, the main source of emissionsfrom a diesel or gas engine is still the exhaust gas.

System overview

The basic function of the oil mist separator module can be seen in Figure 4.1. The oil mist separator isbased on the centrifugal separation principle. Oily gas enters at the bottom of the separator and becauseof the centrifugal forces, the air is driven to the periphery of the disc stack separating the heavier oil dropletsfrom the lighter gases by centrifugal separation. The cleaned air (the process abates odour and smokeemissions as well) exits the separator from the upper pipe connection.

The separated oil is collected through a specially designed draining system. This is carefully designed andtested to prevent already separated oil from re-entering the clean air outlet. The drained oil can be re-usedby the engine and minimizes lube oil consumption. The oil mist separator module should be installed min.10 meter from the engine. It has a cleaning efficiency of 98% and an electrical consumption of max. 1.5kW. The oil mist separator is shown in the below picture. In addition to this, a control cabinet is also supplied.

Figure 6.1 Oil mist separator functional principle

Functional principle

Crankcase gas from the engine1

Crankcase gas enters the separator2

Heavier oil droplets are separated from the lighter gasesby centrifugal separation in the disc stack

3

Drain oil outlet4

Cleaned air/gas to open air5

Restriction/thottle valve6

Balancing pipe (by-pass line)7


Wärtsilä Environmental Product Guide6. Crankcase Vent Systems

7. ANNEX

7.1 Unit conversion tablesThe tables below will help you to convert units used in this product guide to other units. Where the conversionfactor is not accurate a suitable number of decimals have been used.

Table 7.2 Mass conversion factors

Multiply byToConvert from

2.205lbkg

35.274ozkg

Table 7.1 Length conversion factors


0.0394inmm

0.00328ftmm

Table 7.4 Volume conversion factors


61023.744in3m3

35.315ft3m3

219.969Imperial gallonm3

264.172US gallonm3

1000l (litre)m3

Table 7.3 Pressure conversion factors


0.145psi (lbf/in2)kPa

20.885lbf/ft2kPa

4.015inch H2OkPa

0.335foot H2OkPa

101.972mm H2OkPa

0.01barkPa

Table 7.6 Moment of inertia and torque conversion factors


23.730lbft2kgm2

737.562lbf ftkNm

Table 7.5 Power conversion factors


1.360hp (metric)kW

1.341US hpkW

Table 7.8 Flow conversion factors


4.403US gallon/minm3/h (liquid)

0.586ft3/minm3/h (gas)

Table 7.7 Fuel consumption conversion factors


0.736g/hphg/kWh

0.00162lb/hphg/kWh

Table 7.10 Density conversion factors


0.00834lb/US gallonkg/m3

0.01002lb/Imperial gallonkg/m3

0.0624lb/ft3kg/m3

Table 7.9 Temperature conversion factors

CalculateToConvert from

F = 9/5 *C + 32F°C

K = C + 273.15K°C

7.1.1 Prefix

Table 7.11 The most common prefix multipliers

FactorSymbolNameFactorSymbolName

10-3mmilli1012Ttera

10-6μmicro109Ggiga

10-9nnano106Mmega

103kkilo


Wärtsilä Environmental Product Guide7. ANNEX

7.2 Collection of drawing symbols used in drawingsFigure 7.1 List of symbols (DAAE000806c)


Wärtsilä Environmental Product Guide7. ANNEX


Wärtsilä Environmental Product Guide

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WÄRTSILÄ ENVIRONMENTAL PRODUCT GUIDE

WÄRTSILÄ® is a registered trademark. Copyright © 2010 Wärtsilä Corporation.

Wärtsilä is a global leader in complete lifecycle power solutions for the

marine and energy markets. By emphasising technological innovation

and total efficiency, Wärtsilä maximises the environmental and economic

performance of the vessels and power plants of its customers. Wärtsilä is

listed on the NASDAQ OMX Helsinki, Finland.

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