Universidade Federal de Santa Catarina
Centro Tecnológico
Departamento de Engenharia Mecânica
Coordenadoria de Estágio do Curso de Engenharia
Mecânica
CEP 88040-970 - Florianópolis - SC - BRASIL
www.emc.ufsc.br/estagiomecanica
estagio@emc.ufsc.br
INTERNSHIP REPORT – 1/3 (one of three)
Period: 16/03/2009 to 08/05/2009
Westfalia Separator
Student: Harry Schemelzer Neto
Supervisor: Chrisitian Bruns
Counselor: José Carlos Pereira
Oelde –Germany, 8 May, 2009.
Westfalia Separator Systems
SUMMARY
Contents
1.
GEA Westfalia Separator ............................................................................................................. 3
1.1
2.
Westfalia Separator Mineraloil Systems ................................. Error! Bookmark not defined.
Introduction .................................................................................................................................. 5
2.1
Methodology ......................................................................................................................... 5
2.2
Chronogram .......................................................................................................................... 6
3.
Mechanism of separation ............................................................................................................. 7
4.
The Separator .............................................................................................................................. 9
5.
The separation efficiency............................................................................................................ 12
6.
First Project ................................................................................................................................ 13
7.
Test Results and Conclusion ...................................................................................................... 17
8.
References ................................................................................................................................. 18
9.
Attachments ............................................................................................................................... 19
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Westfalia Separator Systems
1. GEA Westfalia Separator
The GEA Group is a global technology group with more than 250 companies in 50 countries.
The company now focuses on specialty mechanical engineering, mainly process engineering
and equipment. The emphasis lies on the two basic engineering processes: heat exchange
and mass transfer.
GEA Group technologies are applied in the food, chemical and petrochemical industries, the
energy sector, air treatment and shipbuilding as well as the pharmaceutical and cosmetic
industries.
Since 1994 GEA Westfalia Separator belongs to the GEA Group. In 2007 the GEA Group
employed around 19.500 people who generated group sales of EUR 5.2 billion
GEA Westfalia Separator, headquartered in Oelde, Germany, manufactures separators and
decanters. These are used for the purification of suspensions, the separation of fluid mixtures
with simultaneous removal of solids and also for the extraction of material constituents and
the concentration or removal of water from solids.
GEA Westfalia Separator's range of business activities is divided into four markets:
Food - applies separators and decanters primarily in the production of beverages, dairy
products and the processing of edible oils.
Industry - specializes in the optimization of separation technology processes in chemistry,
pharmacy, biotechnology, starch technology and the extraction of oils and fats.
Mineral oil - concerns the centrifugal treatment of mineral oils and their derivatives. Its main
applications are in the marine sector, gas turbine and diesel engine power plants, the oilfield
industry, as well as in the maintenance of production facilities and treatment of waste oil.
Environmental Technology - concentrates on the removal and concentration of both
municipal sewage and industrial sewage sludge.
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Westfalia Separator Systems
1.1 Westffalia Separator Systems Gmbh
Westfalia Separator Systems Gmbh has 100 years experience and supports customers in
processing and maintaining mineral oils and related derivatives. The separators can be
applied on the marine, environmental technology, energy and oilfield industry as well as a
wide range of other industries. Considerable sums have been invested in research and
development for many decades with excellent results and it is in this area of Westfalia
Separator that I have been doing my internship.
In the Marine sector, Westfalia separators are used for processing heavy fuel oil and diesel
oil. The separators assure high performance of diesel engines and extend the economic life
of machines, even under extreme conditions.
In the Energy field, the separators are used for the treatment of fuel and lube oils to assure
an efficient removal of water contamination and damaging substances from turbine and
diesel engine power plants.
In the Oilfield industry, the separators are used on onshore and offshore installations of oil
and gas production. They are used in the following applications: processing drilling mud, deoiling of produced and drain water, dewatering of crude oil, cleaning and processing of fuel
oil, lube oil and hydraulic oil and separating cat fines from oil residues.
In the industry, the separators are used for efficiently processing all types of liquid in the
production process. For example: they handle processing of washing lyes which contain oil
and also oil recycling. Cooling lubrication emulsions and cooling lubrication oil are also
processed as inexpensively as hydraulic oil from which dirt particles and water have to be
removed as quickly as possible. High separating efficiencies result in much longer economic
life of the tools and liquids in use.
In the fields of application on environmental technology, the separators are used in
municipalities and industry in the treatment of drinking water, the dewatering and thickening
of sewage sludge and the recovery of valuable materials from production streams as a
contribution to resource-minimized pro
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Westfalia Separator Systems
2. Introduction
The first report presented here refers to the work done from 16 March up to 08 May at
Westfalia Separator under the tuition of Christian Bruns. The internship started with a trainee
program to have an overview of the applications and how the separators work.
To become acquainted with the application of the separator my trainee program started in
Hamburg and I accompanied the technical assistance team on board, in this case, a purifier
of a lube oil where a vibration control in this separator was installed. That was a good
opportunity to see, in practice, one of the products of Westfalia Separator System of the
marine sector.
In Oelde, at the headquarters of the company, I was introduced to the business units of
mineral oil in the offices of the marine, energy and oilfield applications. At the business unit I
have contact with the applications of the products made at the system sector and also how
the factory structure is organized.
To acquire knowledge on how the separators work and of the internal parts I stayed on the
factory floor for a while to accompany the assembly of the separator and the test benches.
After this first trainee program I got acquainted with how the products work and with the
application.
My report begins with the description of the product, what I learned in the training program
and then the introduction of my first project.
My first project consists in doing efficiency tests with a microscope method called countingchamber and sending the results to another company that does these efficiency tests with an
electronic method with laser and comparing the results to see the differences between both.
2.1 Methodology
The internship started with the contact of the application of the separators and how a
separator works, the mechanism of separation and the parts of the separation, the bowl and
the frame. Than start into the first projects that is preview 2 or 3 during the internship.
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Westfalia Separator Systems
2.2 Schedule
Date
Program
Organizational measures (personnel support, work
dwelling, etc.)
Module bases of the centrifugal separation
technology
Trip to Hamburg
16.03
17.03 – 20.03
Contact Person
Bury/ Schulze/ Heydel
Siegeler/ Gebhardt
Siegeler/ Heydel
Basics Mineral Oil Separators (at Training Center Hamburg)
Mauersberger/ Grunert
1 Day Basics, 3 Days Service
Assembly and final test of separators
2,5 Days - Bowl Assembly
23.03 – 03.04
2,5 Days - Frame Assembly
1 Week - Test benches
Freitag/ Hunkenschröer
Kottenstede
Kleigrewe/
Beck
Hentrup/
Acquaintance with Business units:
1 Day - BU Marine
BU Energy
06.04 – 08.04
1 Day - BU Oilfield
BU Fluids and Waters
1 Day - BU 4400 Order Processing Department
09.04 - 08.05
First Project
Poprawa
Stöckl
Perschke
Weweler
Simon/ Lohmeier/ Fibbe
Christian Bruns
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Westfalia Separator Systems
3. Mechanism of separation
The Process
Separators are being used to clean liquids, more specifically, liquid mixtures. Our field of
application is to treat mainly Heavy Fuel Oil, Diesel oil and Luboil as well as Bilge water.
Beside solid particles the water must be removed from the oil or the oil from the water.
In a centrifugal Separator different densities are being used to discharge the liquids and
solids from each other by centrifugal force in a fast rotating bowl
The Sedimentation
In a stationary settling tank liquids of different densities along with the solids will form a
deposit above each other after a certain settling time. This is known as Sedimentation.
Because the densities of the solids are higher compared to water the solids will sink much
faster to the tank bottom. The liquid with the lowest density will float on top after a while.
Big and heavy particles will settle down quite fast to the tank bottom. This will happen even
faster as well as higher the difference in density between oil, water and the solid particles.
G-force
In a separator the sedimentation will take place much faster due to the high bowl speed. The
unit of measurement of the centrifugation acceleration the "times g-force" is being used.
The maximum g-force of a bowl depends on the diameter of the bowl and the bowl speed
and is limited mainly by the bowl material (stainless steel) itself. The separator type OSD6 is
the one with the highest bowl speed (n = 12.000 1/min). The maximum g-force is about
20.000 times force of gravity.
( 2    n) 2  r

9.81  3600
 = Centrifugal acceleration
n = bowl speed [1/min]
r = bowl radius [m]
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Westfalia Separator Systems
Sedimentation surface area, path
The sedimentation becomes more effective with a higher clarification surface area and a
smaller sedimentation path. The design of the settling tank 1 is much better compared to tank
2 with regard to the clarification efficiency.
Bowl: the disk stack
The disk stack is acting like a very high number of flat shallow settling tanks above each
other. There are spacers on top of each disk acting as distance pieces. Because of the short
sedimentation path a disk stack separators is very efficient. The dirty oil will enter the disk
stack from the outer diameter. The clean oil is being discharged in the center.
The solids will be collected on the upper wall of each inter-space and slide down to the
sludge holding space of the bowl. Because of that, the bottom surface must not be scratched
nor suffer on scaling as this will result in reduced efficiency. The bottom sides of disks are
super finish polished by factory.
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Westfalia Separator Systems
4. The Separator
Separators are, beside the product which is being treated, subdivided in the design of the
drive and the bowl:
1. Flat belt drive or gear drive
2. Self-cleaning or non-self cleaning (solid wall bowl)
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Gear
A centrifuge needs a gear because the bowl speed is much higher than the motor speed. A
gear drive consists of a bronze worm wheel and worm spindle. The worm wheel drives the
spindle. Because of that the tooth load is rather high.
The horizontal gear parts are the following: clutch, horizontal shaft, worm wheel, shaft
bearings as well as gaskets and shaft sealing rings. The feed pump is sometimes connected
at the pump drive end of separator
The design of a flat belt drive is not too sophisticated .Because there is no horizontal shaft a
belt driven separator requires always an external feed pump unit.
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Westfalia Separator Systems
The self-cleaning Separator
Onboard of today’s seagoing vessels almost only self-cleaning separators are installed. The
entire process will be monitored and observed by an quite sophisticated control cabinet and
timing unit.
The solids (sludge) collected in the sludge holding space of bowl will be discharged in regular
intervals. When doing so the separation process will be interrupted for the cleaning cycle.
The sludge discharge ports in the bowl bottom will be opened at full bowl speed.
The solid wall bowl
The design of solid wall bowl is easy to understand compared to a self-cleaning bowl.
Even the process is easy to control and the control unit is not too sophisticated. On the other
hand for the manual cleaning a lot of manpower and time is necessary.
During the manual cleaning the separator needs to be stopped. Solid wall bowl separators
are mainly being used for smaller vessels running on Diesel Oil. The amount of solids in
Diesel Oil is not too high.
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Westfalia Separator Systems
5. The separation efficiency
The separation efficiency of a Heavy Fuel Oil (HFO) separator depends besides on the
general condition of the separator skid upon the:
- Density, micron size and shape of the solid particles
- Viscosity and density of the oil
- Temperature
- Clarification surface area of bowl disk stack
- G-force of the bowl
- Flow rate
Flow rate and optimum capacity.
Its is know that separation efficiency is a function of the centrifuge´s flow rate , the higher the
flow rate, the more particles are left in the oil and therefore the lowest separation efficiency.
The curve below shows the efficiency as a function of the flow rate: the efficiency remain
quite constant until dropping at a certain flow rate, these flow rate is called as optimum
capacity. The flow rate is usually constant on the highest viscosity.
.
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Westfalia Separator Systems
6. First Project
In general, marine diesel burn residual fuel oils, the quality of the fuel oils varies widely,
depending on the grade and processing of the fuel. Some may contain higher levels of
contaminants, such as water and abrasive solids, than others.
Catalytic fines and engine performance
Catalytic fines are small particles of spent catalyst, that remain in the fuel after employing
catalytic cracking processes to refine crude oil into more valuable fractions , leaving residual
fuel oil as a bottom phase, enriched in contaminants.
These particles vary size anywhere from submicron to tenths of microns, and can cause
abrasive wear and damage to the engine, that can lead to potentially unsafe operating
condition. That is why the level of catalytic fines must be reduced as much as possible by the
fuel cleaning system.
ISO 8217 and CIMAC fuel recommendation specify that the content of catalytic fines may not
exceed a maximum of 80 ppm, a maximum cat fine content of 15 ppm is accepted before
injection into engine that required minimum separation efficiency of 81 %.
The new standard enables manufacturers to establish a certified flow rate (CFR) for every
centrifuge. Certified flow rate is defined as the throughput rate in liters per hour at which 85%
of five-micron mono-dispersed artificial particles, which simulate harmful catalytic fines, are
removed from a synthetic fuel oil, which simulate a high viscosity fuel oil.
The five-micron particles also help discriminate between good separation and poor
separation at those capacities recommended by centrifuge suppliers. All centrifuges are
capable of cleaning particles that larger than 10 micron, while particles less than 2,5 micron
prove too difficult to separate.
Tests
During laboratory tests the mixture of synthetic oil and plastic particles is heated to a
temperature that provides the same viscosity as a fuel oils(380 mm²/s and 700 mm²/s at 50
°C), when heated to the normal separation temperature of 98°C.
The samples to test is removed from the separation 30 min after , because separation
efficiency generally decreases approximately 15 to 20 minutes after start and then stabilizes
into steady-state condition.
The tests was made with microscopic counting procedure using the THOMA-countingchamber. The counting chamber is a precision measuring instrument made of special optical
glass. It is used to count cells or other particles in suspensions under a microscope.
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Westfalia Separator Systems
All counting chambers have the same basic design principle
There are four longitudinal grooves in the central third of a rectangular and thick base plate
made of special optical glass.
The grooves are parallel to the short sides of the base plate and the central third has the
same size as the cover glass used with the counting chamber. The two larger external
surfaces are unfinished and are used for marking purposes.
The central support and the two external supports are ground smooth and polished. The
surface of the central support is deeper than that of the two external supports. The counting
nets are engraved in the central support (chamber base).
If a cover glass is placed on the external supports, a capillary gap is produced between the
underside of this cover glass and the central support of the counting chamber.
Counting field
Counting assumes precise knowledge of the limit lines of the counting chambers used.
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With the microscope
Test particles
•
•
Mono-dispersed plastic 5 µm particles;
Density: 1050 kg/m³
Test oil
•
•
•
Automotive basic lube oil of type PAO 6
Density: 820 kg/m³ at 20 °C
Viscosity Cinematic
at 100 °C 5,8 mm²/s
at 40 °C
30,2 mm²/s
Calculation
Formula
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With the concentration for inlet and outlet sample calculate the separation efficiency.
Separation Efficiency
η = 100 · (1 – Cout/Cin),
where η is separation efficiency in %,
Cout is number of the test specific particles in cleaned test oil,
Cin is number of the test specific particles in test oil before separator.
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Westfalia Separator Systems
7. Test Results and Conclusion
The tests were made with samples from 2006. They needed to be homogenized in an
ultrasound machine to be tested. The results reached between 80 and 91 percent. These will
be automatic particle counting method to compare the results.
In the electronic tests the particles are identified only by size and the number. The
concentration will be calculated only with the 5 micron particles. Therefore, dust or other
particles may cause counting errors.
These CFR tests are a helpful tool to compare different separator types provided that they
have been tested according to the standard and are designed according to general design
requirements regarding heavy fuel oil separation.
In this first period I learned a lot about separators, their applications, the mechanisms of
separation, the internal parts and the possible mistakes on testing benches and during
assembly.
With the knowledge acquired during this training period and with the knowledge acquired at
UFSC I believe I will be able to develop any project given to me in the company and also
improve my performance in this test and thus, reach more precise results.
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Westfalia Separator Systems
8. References
[1] Westfalia Basic Trainee. Competence Level 1 , Multimedia Westfalia presentation 2008.
[2] Certified Flow Rate (CFR) PowerPoint presentation. 2007 by Cristian Bruns.
[3] Marine diesel engines,catalytic fines and a new standard to ensure operation. Written by
Alfa Laval, BP Marine and MAN B&W Diesel
[4] www.westfalia-separator.com
[5] www.geagroup.com
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Westfalia Separator Systems
9. Attachments
CFR test – OSD 18
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Westfalia Separator Systems
TA Certificate
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Westfalia Separator Systems
Flow Rate table
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