The document discusses the principles and mechanisms of separating impurities from fuel and lubricating oil using gravity and centrifugal processes in purifiers and clarifiers. It outlines how centrifuges operate to remove solids and free water by utilizing centrifugal forces, and details the differences between purifiers and clarifiers, including their design and function. Additionally, it emphasizes the importance of maintenance and the use of filters in preventing impurities in marine systems.

1. Bolivarian Republic Of Venezuela
Maritime University Of The Caribbean
English VI ( Marine Facilitie)
Teacher
Rivas Cesar
Cadets:
Bello Leonardo
Pérez Darwin
Rey Patricia
Yantil Yorgelys

2. By means of gravity in a
settling tank or by means
of centrifuging the fuel.
As a means of removing
impurities from a fuel can
be undertaken.
Gravity acting on the
fuel as it passes slowly
through the tank will
separate the denser
components .

3. The centrifugal separator is used to separate
two liquids, for example oil and water, or
liquid and solids as in contaminated oil.
Purifiers will also remove
some solids
clarifiers will also remove
small quantities of water
The separation of two liquids of
different densities (fuel and
water) are

4. How does a
centrifuge
work?
When a bowl containing impure fuel is rotated,
centrifugal forces will throw any item with
density greater than the fuel oil density (solids
and free water) to the periphery of the bowl .
A centrifuge consists of an electric motor
drive to a vertical shaft on the top of which is
mounted the bowl assembly
Centrifuges work by rapidly spinning a bowl
containing the liquid, thus producing the
required centrifugal force to produce
separation.

5. Purifiers are used on
board ship to condition
fuel oil and lubricating oil
Is correct size gravity disc or
dam ring which is responsible
for creating an interface
between the oil and water.
what is a
purifier?

6. what is a
Clarifier?
Is clarifiers are settling tanks built with
mechanical means for continuous removal of
solids being deposited by sedimentation.
There used to remove solid
particulates or suspended solids from
liquid for clarification and (or)
thickening

7. It contains a stack of disk numbering
up to 150 and is separated from each
other by a very small gap.
Due to the difference in gravity and centrifugal force, the
heavier impure liquid (water) and particles move outside and
lighter clean oil flows inwards and gets separated.
In a purifier, before introducing the oil, water sealing is
established so that oil fill should not flow out through
the heavy liquid outlet
In clarifier, there is no heavy liquid
outlet for discharging separated
water hence water sealing is
unnecessary

8. The centrifugal separation of two liquids, such
as oil and water, results in the formation of a
cylindrical interface between the two.
The setting or positioning of the interface is
achieved by the use of dam rings or gravity discs
at the outlet of the centrifuge.
Various diameter rings are available for each
machine when different densities of oil are used.
As a general rule, the largest diameter ring
which does not break the 'seal' should be used.

9. Cleaning oil which contains little or no water is
achieved in a clarifier bowl where the impurities and
water collect at the bowl periphery.
A clarifier bowl has only one outlet.
No gravity disc is necessary since no interface is formed; the bowl
therefore operates at maximum separating efficiency since the oil is
subjected to the maximum centrifugal force

10. Where a centrifuge is
arranged to separate two
liquids, it is known as a
'purifier'.
Where a centrifuge is
arranged to separate
impurities and small
amounts of water from oil
it is known as a 'clarifier'.

11. Purifiers Clarifiers
Is to separate the dissolved water,
impurities and sludge from the fuel
oil.
Removes any solid foreign material
that is not removed from the oil after
it passes through the purifier.
 Presence of a dam ring. the interface or the line of
separation between the oil and water
is created using a dam ring.

12. The bowl and the disc stack will require periodical cleaning whether or not an
ejection process is in operation. Care should be taken in stripping down the bowl,
using only the special tools provided and noting that some left-hand threads are
used.
The centrifuge is a perfectly balanced piece of
equipment, rotating at high speeds: all parts should
therefore be handled and treated with care.
It is important that there is proper maintenance,
record of correct parameters and prevention of
impurities from entering the systems.

13. Is incorporated with filters and strainers which help in
removing contamination from the system.
The first and second points are a part of routine duties;
however for preventing impurities from entering, it is
important that every system.
The schedule is normally included in the planned
maintenance system on board.

14. A filter is a fine mesh screen which is used to
remove impurities from oil, water and air on ship.
Filters are mounted in pairs as a duplex system so
that one can be used and other is kept on standby at
a time.
Filter can be used both in low pressure (suction) and
discharge (high pressure) side of the system and is used to
remove the smallest part of dirt which is carried away in the
system.
The cleaning frequency of filters depends upon the type of
the filter.

15.  https://www.marineinsight.com/guidelines/high-speed-centrifuge-on-
ship-construction-and-working/
 https://www.quora.com/In-ships-what-is-a-purifier
 http://marineengineeringonline.com/centrifugal-purifiers/
 https://en.wikipedia.org/wiki/Clarifier