Purifier Notes

8/11/2019 Purifier Notes

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The S-Separator

Technical information for mineral oil treatment


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Inside view

3 Summary

4 The Alfa Laval S-Separator SystemsConventional cleaning with purifier systems

Separation results with purifiers

Limitations common to conventional purifiers

Limitations common to conventional clarifiers

8 The ALCAP technologyOperating principle

Medium free water contamination

High free water contamination

Transducer MT 50 operating principle

Dielectric constant approximate values

11 The separatorDesign features

14 Flow diagram

16 Separation performance

Factors influencing separation efficiencySystem layout

Separation efficiency test method

Separation Performance Standard

19 Remote operation

This technical information deals with the S-Separator whichprovides the highest separation efficiency for mineral oil treatmentever achieved.


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Alfa Laval Marine & Diesel Equipment 3

The Alfa Laval S-Separator

Summary

The Alfa Laval S-Separator is an automated single-stage separation system

for the cleaning of fuel oil and lubricating oil.

Based on the well established ALCAP technology, this

compact system consists of a high-speed separator and

ancillary components together with control system and

starter box. It can be delivered in a fully integrated modular

design on its own base plate or, to facilitate delivery, as six

individual components that can be assembled on site.

Available in a full range of sizes and in different configurations,the S-Separator delivers higher cleaning efficiency than pre-

vious models and drastically reduces operation and main-

tenance costs.

Innovations include:

a compact separator bowl which reduces sludge produc-

tion and loss of oil,

a new disc stack design to ensure optimal flow patterns

and separation characteristics,

the non-threaded CentriLock spring lock ring which is

easy to snap on and pop out, and,

the CentriShoot discharge system, which replaces the

sliding bowl bottom with a patented, flexible discharge slide

that is fixed within the bowl body.

The purpose of this document is to provide technical infor-

mation about the Alfa Laval S-Separator system. This includes

information about the separation process, advances in system

design, system benefits and a description of equipment.

Benefits

Highest separation efficiency available. In laboratory tests,

the Alfa Laval S-Separator removes over 85 percent of all

5-micron particles to ensure fuel and lubricating oils do not

contain harmful contaminants. This effectiveness measures

up to the Separation Performance Standard.

Low installation costs. Compact, modular, flexible design

saves space and reduces installation costs.

Faster, more secure commissioning with full technical support

during design, installation and startup even for retrofits.

Big savings on operation and maintenance costs.The

S-Separator provides continuous monitoring of clean oil,

reduces sludge by up to 75 percent, and minimizes wear

and tear on the bowl. Compared to previous separator

models, the spare parts inventory has been reduced and the

service intervals prolonged.

Easy-to-access, easy-to-operate equipment provides auto-

matic, start-and-forget systems that are designed for remote

control and operation.

No adjustments required to the gravity disc or other system

components for continuous optimum separation efficiency

despite fluctuations in density and viscosity.

Proven key components provide more uptime, high reliability,

consistent performance and low maintenance.

Longer service intervals. Longer-lasting construction prolongs

service intervals and reduces spare parts consumption by up

to 50 percent compared to conventional systems.


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4 Alfa Laval Marine & Diesel Equipment

The Alfa Laval S-Separator Systems

The Alfa Laval S-Separator is the principle component of a range of high-

efficiency mineral oil separation systems. Based on proven ALCAP oil treatment

technology, the Alfa Laval S-Separator combines fuel oil and lubricating oil

treatment into a single separator, thanks to software that makes it possible to set

the relevant parameters in the process controller.

The Alfa Laval

S-Separator.

The Alfa Laval S-Separator system can handle:

Heavy fuel oils with high densities up to 1010 kg/m3 and

viscosity up to 700 cSt/50C. Handling of higher viscosity

is available upon request.

Lubricating oils for all diesel engine types.

Distillates and light diesel oils (MDO).

The Alfa Laval S-Separator systems consist of a separator

and its ancillary components, together with control system

and starter box. It can be delivered in two ways:

1.as the Alfa Laval Separator Ancillary (SA) system, which

consists of six individual components that can be assembled

on site to facilitate delivery, or,

2.as the Alfa Laval Separator Unit (SU), which is a fully inte-

grated modular system on its own base plate.

Both systems include:

an high-speed S centrifuge, an EPC50 process controller,

an MT 50 transducer (capacitive transmitter), and,

ancillary equipment.


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SU Separation Unit

Easy to work with but occupying only a minimum volume,

the plug-and-play Separation Unit integrates a separator

and ancillaries with a control cabinet and starter box. With

all components pre-installed on a single base plate, you

save installation time, materials and space.

SU Module

The plug-and-play SU Module combines a Separation Unit

with a heater and feed pump. This makes it a complete oil

cleaning system and an optimum solution for protecting

your engine. Double and triple configurations are also avail-

able, each mounted on a single base plate with all of the

interconnecting piping.

To further simplify the design process, 3-D AutoCAD drawings for all separator configurations are available in electronic format.

SA Separation Ancillaries

A non-integrated solution, the SA separation system lets

you minimize your initial investment by assembling it on site.

Specialized block components let you determine the

arrangement, and each component is pre-tested to ensure

a perfectly working system.

Water blockOil block

EPC50 control unitAir block Optional starter

Sludge outlet kit


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840 950 970 991Fuel density kg/m3at 15C

nterace

postonsenstvty

Figure 1. Interface positions sensitivity.

840 950 970 991Fuel density kg/m3at 15C

Gravitydisccapability

Figure 2. Capability of the gravity disc to cope with disturbing factors.

Figure 3. Purifier problem area.

Purifierproblemarea

Interfacesensitivity

PURIFIER

PURIFIER +CLARIFIER

ALCAP FOPX

Fueldensity

Gravity discinsufficiency

960

991

1010

+

Conventional cleaning with purifier systems

Conventional cleaning plants are based on purifier type

separators. Practical operation has clearly proven that the

generally accepted maximum density limit for fuel oil is

991 kg/m3 at 15C. This maximum density limit may be

exceeded at bunkering, which may result in operational

difficulties with the cleaning plant.

Consequently, the purifier type of separator restricts the use

of available fuel oils. For lube oil cleaning, the conventional

purifiers are still an option.

Separation results with purifiers

To achieve optimum separation results using purifiers, the

interface between oil and water in the bowl must be outside

the disc stack.

The interface position of a purifier is adjusted by means

of gravity discs. To get the correct interface position thepurifier must be fitted with a correctly sized gravity disc.

This presents an operational dilemma with changing oil

properties.

With higher fuel densities, maintaining optimum separation

results by means of gravity discs becomes increasingly diffi-

cult. Factors that affect the interface position are changes in

oil density, viscosity, feed flow rate and temperature.

With increasing fuel density, the interface position

becomes progressively more sensitive to these factors

(Figure 1).

Unfortunately, gravity discs experience the same progressive

sensitivity to these disturbing factors. The capability of the

gravity disc therefore declines progressively with increasing

fuel density (Figure 2).

Thus, as the interface position becomes more sensitive to

disturbing factors, each successive gravity disc has a

reduced capacity to cope with them (Figure 3). In practice,

problems with the purifier develop well before the fuel density

reaches 991 kg/m3.

Temperature fluctuations, inherent in even the best tempera-

ture control systems, cause viscosity fluctuations. However, a

proportional integral (PI) temperature controller will consider-

ably reduce this source of disturbance.


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Limitations common to conventional purifiers

The basic problem in treating heavy fuel oil is the gravity disc:

It restricts the use of diesel engine fuels to those with

a maximum density of 991 kg/m3 at 15C.

Optimum separation depends on selecting the correct

gravity disc, which corresponds to the prevailing density,

viscosity, feed flow rate and temperature. This becomes an

impossible task in practical operation with the fluctuation of

density and viscosity, particularly with high-density fuels of

991 kg/m3 at 15C and above.

Checking and fitting the gravity disc is time-consuming and

unpleasant. Since the correct gravity disc is defined as the

largest disc that does not cause a broken water seal, it can

be a frustrating trial-and-error process. Alarms for broken

water seals can be frequent. Consequently, the gravity disc

selected tends to be undersized and the oil cannot be

adequately cleaned in a purifier alone.

To ensure satisfactory cleaning a second separator is

required in series operation. This creates a separation

system of a purifier followed by a clarifier as a safety net.

This system, however, is still restricted to oils with a

maximum density of 991 kg/m3 at 15C.

Limitations common to conventional clarifiers

The basic problems when treating fuel oil of any density in a

clarifier are oil losses and limited water handling capability.

Oil losses

When operating a separator in clarifier mode, no displace-

ment water is added prior to sludge discharge. Therefore, not

only sludge and separated water are discharged, but a cer-

tain volume of oil is discharged, too.

Limited water handling capability

For optimum separation efficiency separated water must

not enter the disc stack. The separated water can only be

discharged with the sludge through the sludge ports at the

bowl periphery since the water outlet is closed in a conven-

tional clarifier (Figure 4).

If a clarifier is used without a purifier in the first stage and

with elevated water content, sludge discharge occurs

frequently at short intervals because no other method ofdischarging separated water exists.

Sludge discharge causes turbulence in the bowl and

therefore discharging sludge too frequently decreases

separation efficiency. Consequently, the water handling

capability of a conventional clarifier is insufficient for

cleaning fuel oil.

Water outletclosed

Figure 4. Conventional clarifier water discharge.


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Oil

Sludge

and water

MT

Water

Disc stack

Watertransducer

Figure 6. High free water contamination.

The ALCAP technologyOperating principle

Dirty, pre-heated oil is continuously

fed to the S-Separator, which essen-

tially operates as a clarifier. Clean oil is

continuously discharged from the clean

oil outlet. Separated sludge and water

accumulate at the periphery of the

bowl.

When separated water approaches

the disc stack, traces of water start toescape with the cleaned oil. This minor

increase in water content of the cleaned

oil is detected by the transducer MT 50,

which is installed in the clean oil outlet.

Increased water content in the

cleaned oil is a sign of reduced sepa-

ration efficiency not only of water, but

of solid particles too.

The transducer continuously measures

changes in water content. No absolute

values of water content or volume are

involved. The transducer measures the

deviation from a non-calibrated refer-

ence value and transmits a signal to the

EPC50 process controller for inter-

pretation. Measurements that fall within

the permissible deviation values are

known as the trigger range.

The EPC50 process controller stores

a new reference value after the trans-

ducer stabilization time that follows

every sludge discharge sequence has

elapsed. During the reference time the

best possible separation result is

obtained.

At the trigger point, which is when the

water content in cleaned oil reaches

its maximum allowable deviation of

approximately 0.2 percent, the EPC50

process controller initiates an automatic

discharge of the water that has accu-

mulated in the separator bowl.

Figure 5. Low free water contamination.


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Depending on the amount of water

in the oil, water is discharged either

through the water drain valve, or with

the sludge through the sludge ports at

the periphery of the bowl.

Medium free water contamination

When separated water approaches the

disc stack the transducer signal triggers

the EPC50 process controller to openthe water drain valve.

High free water contamination

When excessive amounts of water are

present in the feed and if the water

drain valve activation does not provide

sufficient drainage, the EPC50 process

controller automatically initiates a

sludge discharge.

Transducer MT 50 operating principle

The transducer includes a cylindrical

capacitor through which the full flow of

cleaned oil passes, forming a dielectric

medium. The working principle of the

transducer exploits the large difference

between the dielectric constants of

mineral oil and water.

Dielectric constant

approximate values

Mineral oil 24

Water 80

The dielectric constant of oil contami-

nated with water increases when the

water content of the oil increases, and

vice versa. Changes in the dielectric

constant of the cleaned oil are very

sensitive, convenient measures of

changes in its water content.

MT

Transducer

Figure 7. High free water contamination water drain valve activated.

Figure 8. High free water contamination sludge discharge.


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The separator

With its unique design features, the centrifugal separator incorporated in the

range of S-Separators is the most advanced separator ever produced for the

marine and power industries.

Longer intervals between service have a positive effect on

overall life cycle costs compared to those of previous sepa-

rator models.

All components, from the simple belt drive to the design of

the new bowl, have been thoroughly tested both in laboratory

trials and in rigorous field tests under normal and forced

operating conditions.

Drive

The separator is driven by an electric motor via a flat belt to

the spindle that is supported in the frame by bearings and

special composite springs. No tensioning of the drive belt is

required.

This configuration provides reliability and long intervals

between service.

Bowl

The bowl, which is fixed at the top of the spindle, contains

the most advanced changes found in the separator.

Fluid dynamics studies have been extensively used in the

design to ensure the best possible flow patterns. This is

especially true in the case of the disc stack, which has been

optimized to provide high separation characteristics and to

help keep the bowl free from sludge deposits.

The bowl has a simple paring tube, instead of the conven-

tional heavy phase paring disc, that floats on the surface

of the heavy water phase. This patented paring tube system

minimizes oil losses and enables use of the same bowl

configuration on all fuel and lube oil types.

As with all bowls using ALCAP technology, no adjustments

are necessary and no gravity discs are fitted.

Because of its high speed and advanced design, the bowl

is appreciably smaller than those of previous separator

models for a given capacity requirement. This compact bowl

is a factor that contributes to the small overall size of the

separator.

Figure 9. The S-Separator.

Paring tube

Seal ring

Discharge

ports

Discharge

slide

CentriLock

Untreated oil

Clean oil outlet

Water outlet

Figure 10. Separator bowl.


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Discharge system

The separator operates with the new CentriShoot discharge

system. The sliding bowl bottom of previous models has

been replaced by a discharge system that uses a patented,

flexible discharge slide that is fixed in the bowl body.

During discharge, only the outer periphery of the disc flexes

downward exposing the discharge ports. The frame of the

separator easily absorbs the impact forces in the sludge.

Because of the smaller bowl volume, longer intervals between

sludge discharges and more accurate controls, the newsystem provides efficient sludge removal but with less oil loss,

lower water consumption and less total waste production

than previous models.

CentriLock lock ring

In the new separators, a simple snap-in spring lock ring, for

which patents have been applied, has replaced the traditional

threaded lock ring, the lock ring spanner and the sledge-

hammer.

The bowl is assembled and then compressed, using the

mechanical disc stack compression tool that comes with the

S-Separator. This enables the spring lock ring to snap easily

into place.

Removal is equally simple. An Allen key loosens grubscrews set into the outer wall of the bowl and the lock ring

pops out.

STEP THREE:After discharge, the slide moves gently

back into position, closing the ports. Closing is done

hydraulically, without any springs.

STEP TWO: During sludge discharge, the edge of the

slide flexes downward, exposing the ports.

STEP ONE: CentriShoots discharge slide is fixed at the

centre. During separation it covers the discharge ports.

Figure 11. CentriShoot discharge system.

CentriLock can be removed with only an Allen key.

No sledgehammer is necessary.

CentriLock lifts out and snaps in easily without any

threads to wear.

Threaded lock rings

must be removed with

a sledgehammer. Over

time, metal-to-metal

wear between bowl

and lock ring lead to

expensive bowl repair

or replacement.

Figure 12. CentriLock lock ring.


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Inlet/outlet parts

The inlet/outlet parts of previous models consisted of several

parts that required individual assembly. These individual parts

have been replaced in the new separator by a single housing

to which the inlet/outlet hoses are connected.

When opening the separator, the hoses are disconnected first

and secured to one side for reconnection. The entire housing

can then simply be removed as a single piece.

Ancillaries

The system can be delivered either pre-assembled as a

single compact pre-tested unit that includes the separator

and ancillary unit mounted together, or as loose block-

mounted components with the separator and ancillaries as

individual units.

Ancillaries systemGood engineering principles have yielded improvements in

the new ancillaries unit compared with the ancillary systems

supplied with previous models. Instead of having to connect

several different components, the new ancillary system con-

sists of three blocks.

The main block consists of the inlet and outlet connections,

control and regulating valves, temperature and pressure

transmitters, and the water transducer built into a single

block.

The two smaller blocks for operating water and air

are connected as the unit is built.

Six pipe connections are required for the S-Separator:

Oil inlet

Clean oil outlet

Oil recirculation outlet

Operating water

Operating air

Sludge outlet.

Sludge Removal Kit

for use with the Separation Unit

Thanks to the new discharge system it is no longer

necessary to have a large sludge tank under the sepa-

rator. Instead, a very small intermediate sludge tank can

be mounted on the base plate between the separator and

the ancillaries unit.

The intermediate sludge tank is equipped with a level

switch and an air-operated pump that pumps away the

sludge after each discharge. The tank is also equippedwith a connection for a small vent pipe to the nearest tank

ventilation. The Sludge Removal Kit provides flexibility in

the placement of a separation unit.

EPC50 process controller

The control cabinet for the separator unit combines the motor

starters and the process controller into a single unit. However,

the separator ancillary system requires the process controller

to be installed in a separate cabinet.

Maximum reliability and user-friendliness were among the major

design considerations for the new EPC50 process controller.

In addition, the EPC50 introduces several new functions that

are now available due to changes in the instrumentation.

Pressure transmitters have replaced pressure switches in the

ancillaries unit, providing a higher degree of accuracy and reli-

ability. They also supply the process controller with a contin-

uous stream of information.

Instead of the message codes used in previous systems, the

new unit provides information in clear language in a rolling

text window. Eight different languages are provided as stan-

dard, enabling the operator to select the language of choiceat the initial start-up. Further support for the rolling text mes-

sages is provided in the Instruction Book.

In rigorous tests over many years, the process controller has

proven to be stable and the light-emitting diode (LED) display

legible under conditions of high humidity and temperatures of

55C and above. The EPC50 has been granted approval

from many classification societies.



Figure 13. EPC50 process controller.


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Feed PumpFeeds unprocessed oil to the

separator.

HeaterHeats unprocessed oil to the

separation temperature.

Temperature transmitterMeasures the oil temperature and

signals the process controller.

Pressure transmitter, oilMeasures the pressure in the oil

inlet, and signals the processcontroller.

Pneumatically controlledchangeover valve

Leads the untreated oil to the

separator, or back for recirculation.

Process controllerSupervises the S-Separator.

Pressure transmitter, oilMeasures the pressure in the oil

outlet and signals the processcontroller.

TransducerContinuously monitors changes in

water content in the oil outlet and

signals the process controller.

Provides a separation efficiency

check.

Flow diagram

Conditioning water

Opening water

Closing water

Water inlet

Untreated

oil inlet

Oilreturn

Optional

PTTT


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Regulating valveRegulates the back-pressure

in the clean oil outlet.

Pneumatically controlledshut-off valve

Closes the clean oil outlet.

Solenoid valve block, waterDistributes separator

opening/closing water and

conditioning water.

SeparatorCleans the oil by removing water

and solid particles.

Pressure transmitter, waterMeasures the pressure in the water

drain outlet and signals the control

unit.

Drain valveOpens when water is drained from

the separator.

PT MT

PT

Clean oil outlet

Water outlet

EPC50 Control Unit

Sludge outlet to sludge tankor Sludge Removal Kit

Separation Unit


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Separation performance

Catalytic fines introduced during the refinery process of heavy fuels can cause

premature wear of components and engine breakdown. Therefore, good

separation performance is imperative.

Factors influencing separation efficiency

Several factors influence separation efficiency, such as:

Separation temperature

Separation viscosity

Feed rate

Utilization of the disc stack

Densities of the light phase (oil) and heavy phase (water)

Size and number of solid particles in the feed Amount of water in the feed

Chemical characteristics of the oil

System layout

Single-stage operation is the normal operating mode, which

generally provides sufficient separation efficiency.

Fuel oil varies considerably in terms of viscosity, density and

the amount of solids, water and other characteristics present.

On those occasions when the fuel oil contains elevated levelsof abrasive wear particles and/or water, parallel operation

splitting the feed rate equally between the two separators is

recommended to maintain sufficient separation efficiency.

Series operation will not improve the separation efficiency

to the same degree as parallel operation. Consequently, the

S-Separator cannot be operated in series configuration.

Lube oil is not subjected to variations in viscosity and density,therefore a correctly sized separator in single-stage operation

that is properly operated fulfils the requirements to achieve

the desired separation result.

Separation efficiency test method

One of the major challenges facing the development team

was the lack of a reliable method for testing the separation

efficiency of the new separator during the various stages of

the development work. This required a method that closely

approximated normal operating conditions, but would provide

accurate and reproducible results to establish a standardseparation efficiency test method.



0 1 2 3 4 5 6

0

20

40

60

80

100

Separation vs. flow rate

Flow rate [m3/h]

Separation[%

]

5mparticles

Figure 14. Separation of plastic particles versus flow rate in an older Alfa Laval model.


19/24Alfa Laval Marine & Diesel Equipment 17


In the early 1980s, Alfa Laval carried out separation efficiency

tests using a typical fuel oil.

Both before and after separation, the levels of contaminants,

expressed as aluminium and silica, were measured both by

weight and by particle size using a particle counter. These

tests indicated separation efficiencies for particles greater

than 5 micron in the region of 70 to 80 percent for ALCAP

separators. The tests also showed that a single ALCAP

separator could replace the traditional purifier/clarifier in

series operation.

Instead of catalyst fines, monodisperse spherical plastic

particles size 5 micron are used. This is relevant with respect

to the tolerances found in fuel injection and engine lubrication

systems. These particles are produced to very exact dimen-

sions and densities.

In typical laboratory tests, the prepared mixture of synthetic

oil and plastic particles is heated to a temperature that providesthe same viscosity as fuel oils (380 and 700 cSt @ 50C)

when heated to the normal separation temperature of 98C.

The material is then fed through the separator at different

feed rates, and samples are taken at fixed intervals after a

discharge.

The method demonstrated that the test could produce

consistently reproducible results for a given set of conditions.

The test therefore was considered suitable as a highly accu-

rate test method to determination separation efficiency.

Typical data from test results show a gradual decrease in

separation efficiency as flow rate increases (Figure 14).

Good correlation was also found between this method and

separation tests carried out at 98C on a sample of fuel oil

containing catalyst fines.

It is known that separation efficiency is a function of capacity

and that, if capacity is raised, then separation efficiency will

decrease. To maintain separation efficiency when capacity is

increased, improvements must be made to the separator in

order to provide the desired separation efficiency at the

increased capacity (Figure 15).

Despite the fact that modern bunkers often have good

quality and contain low amounts of catalytic fines, under-

dimensioning separation systems is inexcusable.

Occasionally, highly contaminated bunkers or bunkers with

poor separation characteristics may occur. Other parameters,

such as separation temperature and the cleanliness of the

disc stack, fluctuate.

To maintain a safe margin against poor separation perfor-mance, even during such conditions, a separation system,

which is amply over-dimensioned for easy treatment of

bunkers, is required. This may be regarded as an insurance

fee that pays off during demanding conditions, such as when

other systems do not perform satisfactorily and lead to costly

engine wear and unreliable operation.

Similar reasoning applies for lube oil systems. Although

the characteristics of the oil do not vary much, other para-

meters can have noticeable influence on the separation

efficiency. It is important to dimension the system for the

worst-case scenario. Otherwise unacceptable engine wear

can result.

0

20

40

60

80

100

Flow

Separation[%

]Imp

roved

Decrease in separationefficiency due to increased

recommended capacitywithout improved design.

Old

Oldrec.cap

Increasedrec.cap

a c

b

Figure 15. Illustration of the effect of increased flow design in a separator.

a) Old point of operation.

b) After increasing capacity without change in design.

c) Improved design gives high efficiency of increased flow.


20/24



Separation Performance Standard

Establishing a separation performance standard enables:

Fair comparison of different separators,

Good reliability of the diesel engine, and,

Economical operation of the diesel engine.

Of all the contaminants contained in residual fuels, the

most damaging are catalytic fines. These are hard, abrasive,

irregularly shaped particles of aluminium silicate, which must

be removed, or at least reduced, to acceptable levels before

the fuel oil is injected into the engine. If cat fines remain,

they can lodge in injection pumps, piston rings and cylinder

liners, causing serious wear that can over time lead to break-

downs.

According to ISO 8217 standards, the maximum allowable

cat fines in bunkered fuel is 80 parts per million (ppm).

However, because engine builders typically stipulate a

maximum of 15 ppm in fuel oil, fuel oil is rigorously cleaned

by centrifugal separation before it enters the engine.

Currently, fuel oil separator selection is based on the

Maximum Recommended Capacity (MRC) tables provided

by the manufacturers. It is known that separation efficiency

is a function of the separator flow rate. Generally, the higher

the flow rate, the higher the number of particles that remain

in the oil, and the lower the separation efficiency. But as the

flow rate is reduced, particle removal increases and cleaning

efficiency improves. It is, however, essential to know at what

capacity adequate separation efficiency is reached in the

typical case.

There is no recognized reproducible method for measuring

the relationship between capacity and separation perfor-

mance. Therefore no one can be absolutely sure that separa-

tors chosen according to the MRC actually provide safe

removal of harmful catalytic fines from the heavy fuel oil

before injection into the engine.

Fuel system suppliers do not believe that it is possible to

compensate for poor separation or to provide adequate back

up to ensure separation performance by installing a fine filter

downstream of the separator. The filter would only capture

particles of 10 micron or more, while smaller cat fines that

remain would pass through the system. Centrifugal separa-

tors can remove particles as small as two micron.

In cooperation with several classification societies, Alfa Laval

has provided a de facto standard for independent verification

of separation performance based the DNV-approved Dyno

Test Method. This is an alternative to specifying separator

performance based on the MCR; the new standard is

expressed as Certified Flow Rate (CFR).

A separators CFR is the throughput rate at which 85 percent

of 5 micron monodispersed plastic particles, which simulate

harmful catalytic fines, are removed from the test oil, whichsimulates a high viscosity fuel oil. The CFR represents a safe

level for continuous, efficient separation and provides the

industry with independent verification of separation perfor-

mance. This makes it possible to compare fuel oil separators

based on separation efficiency rather than on throughput

capacity.

With CFR measured for every separator, customers can

specify a unit of the correct size for the task, with the knowl-

edge that the installed unit will suit its intended purpose and

eliminate the risk of installing an undersized unit.

Because catalytic fines are not available in any standard size

distribution, it is impossible to create a standard based on the

evaluation of tests using real cat fines, or real heavy fuel oil.

Fuel oils also vary in terms of chemical characteristics, which

affect the polarity, and physical characteristics such as

density and viscosity.

Due to these wide variations, it is impossible to obtain repeat-

able and comparable results from tests made on actual

bunkers. The 5 micron monodispersed plastic particles, or

Dynospheres, are identically sized, homogeneous, sphericalplastic particles, normally used for the calibration of instru-

ments.

The development of the Separation Performance Standard is

positive for the shipping industry as a whole. For the ship

owner, the overall benefits are clear: different separators can

be compared on equal terms based on a reliable independent

international performance standard.

The owner may find that investment in a larger separator is

required when basing selection on CFR. This, however, can

be compared with buying a separator with an insurance fee

against damage to the engine caused by inadequate separa-

tion. Analyses indicate that a reduction in engine wear of as

little as two percent makes the selection of separators

according to CFR a profitable investment. At a given flow

rate, a larger separator will always provide higher separation

performance than a smaller one.


21/24

Remote operation

Unlike previous systems, the S-Separator has several options for remote

operation. This has been made possible due to built-in safety features,

such as a speed sensor and a vibration sensor.



Depending on the installation, the alternatives for remote con-

trol include:

Bus communication that enables up to nine systems to be

connected as a network. Installation of the customers own

software package enables remote operation. A MODBUS

or PROFIBUS board must be installed in each EPC50

process controller.

An additional EPC50 control panel (remote operator panel)

that can be installed for local operation or for operation

from an alternative location.

A simple remote operation version that uses two switches

connected to an I/O expansion board.

A junction box that can be installed on the S-Separator to

enable positioning of the control cabinet at a location away

from the separator itself.

Each alternative provides safety interlocks to prevent acci-

dental operation in un-safe conditions.

REMIND

As standard, each complete delivery of the S-Separator

includes a REMIND software package for local monitoring

only, a short connecting cable and an operating manual.

This allows the operator to install the program disks on a

laptop computer that is then connected to the EPC50

process controller. REMIND can then review and store the

alarm history and the processing parameters in the laptop.This data may be used later to check processing conditions

and for troubleshooting.

Full instructions for the installation of the various systems are

given in Instruction Books.

Figure 16. Remote control network version.


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The Alfa Laval S-Separator is ideal for new building

applications as well as for replacing older separator

units or supplementing existing cleaning systems.

Its compact size easily fits into available space in an

existing engine room. It can also be divided into four

parts in order to facilitate transport through small

passageways.

In addition, the pipe connections for the separator

units enable greater flexibility for the placement of the

unit; the units no longer need to be located over the

sludge tank or in the same place as the unit it is

replacing.

Alfa Laval supplies each S-Separator with full docu-

mentation either as paper copies or as PDF (Portable

Document Format) files on a CD-ROM. Documentationis clearer and easier to understand, thanks to improved

graphics. The instruction manual, which can also be

made available in most major languages, covers:

Safety

System description

Operating instruction

Parameter list

Alarms and fault finding

System reference/installation instructions

Service manual

Spare parts catalogue

Documentation

Alfa Laval ensures that the S-Separator fulfills the

requirements of all major classification societies. Upon

request, Alfa Laval delivers each S-Separator with an

individual test certificate. This includes approval by the

society of the main components as well as workshop

testing of the complete module. Most key

components are also type approved by the leading

classification societies.

Alfa Laval provides spare parts kits for all service and

maintenance needs. Global technical service, training

and support are available throughout the lifetime of the

S-Separator.

Retrofitting

Classificationsociety approval Spare parts,service and

support


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Alfa Laval reserves the right to make changes at any time without prior notice.

Any comments regarding possible errors and omissions or suggestions for improvement

of this publication would be gratefully appreciated.

Copies of this publication can be ordered from your local Alfa Laval company.

Published by: Alfa Laval Tumba AB

Marine & Diesel Equipment

SE-147 80 TumbaSweden

Copyright Alfa Laval Tumba AB 2004.


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Alfa Laval in brief

Alfa Laval is a leading global provider

of specialized products and engi-

neering solutions.

Our equipment, systems and services

are dedicated to helping customersto optimize the performance of their

processes. Time and time again.

We help our customers to heat, cool,

separate and transport products

such as oil, water, chemicals, bever-

ages, foodstuff, starch and pharma-

ceuticals.

Our worldwide organization works

closely with customers in almost 100

countries to help them stay ahead.

How to contact Alfa Laval

Contact details for all countries are

continually updated on our web site.

Please visit www.alfalaval.com to

access the information.

toskrift.se

2004

Purifier Notes

Documents

Transcript of Purifier Notes