ENSEMBLE DE TRAITEMENT D'UN FLUIDE PAR FILTRATION ET CENTRIFUGATION

ASSEMBLY FOR PROCESSING A FLUID BY FILTRATION AND CENTRIFUGATION

Abrégé français

L'invention est relative à un ensemble de traitement d'un fluide comprenant un filtre (4) comportant lui-même des éléments filtrants (5) et un dispositif (12) de nettoyage périodique de chaque élément filtrant incluant un conduit (17) d'évacuation du fluide de nettoyage chargé des impuretés résultant du nettoyage, l'ensemble de traitement comprenant également un dispositif de centrifugation comprenant lui-même une enceinte rotative (37) raccordée à un conduit (28) d'admission de fluide. Selon l'invention, les éléments filtrants (5) et l'enceinte (37) sont contenus dans un carter unique (1A-1B), cependant que le conduit (28) d'admission est raccordé directement (29-30) au conduit (17) d'évacuation du fluide de nettoyage. Une application est la réalisation d'un ensemble compact et fiable.

Abrégé anglais

The invention relates to a fluid treatment assembly comprising a filter (4)
which itself comprises filtering elements (5) and a cleaning device (12) for
periodically cleaning each filtering element including a conduit (17) for the
evacuation of the cleaning fluid filled with impurities resulting from the
cleaning,
the treament assembly further comprising a centrifuging device which itself
comprises a rotary enclosure (37) connected to a fluid admission conduit (28).
According to the invention, the filtering elements (5) and the enclosure (37)
are contained in a single casing (1A-1B), while the admission conduit (28) is
directly connected (29-30) to the conduit (17) for evacuating the cleaning
fluid.
The invention finds an application in the construction of a compact and
reliable assembly.

Revendications

6
We claim:
1. A treatment assembly for treating a fluid comprising:
a filter device having at least one filtering element; said filtering element
including an
inlet for fluid to be filtered, an outlet for filtered fluid, and a filtering
surface;
a centrifuging device including a rotary enclosure having an admission
conduit, an outlet
for purified fluid, and means for rotating said rotary enclosure; and
a cleaning device for cleaning said at least one filtering element, said
cleaning device
including:
a motor driven rotary distributor, for periodically isolating one part of the
filtering surface
in order to allow counter-current cleaning thereof by clean counter-current
fluid flowing
through said at least one filtering element, the rotary distributor including
an evacuation
conduit which communicates with said admission conduit for feeding the counter-
flow
fluid to be purified to the centrifuging device.
2. The treatment assembly of claim 1, wherein:
the evacuation conduit directly opens out into the admission conduit of the
rotary
enclosure.
3. The treatment assembly of claim 2, wherein:
said filter device and said rotary enclosure are contained in a single casing.
4. The treatment assembly of claim 3, wherein:
the evacuation conduit has a first end and a second end;

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the admission conduit has a first end and a second end;
the admission conduit first end is fitted in said evacuation conduit first
end; and
the admission conduit second end is fixed to said single casing.
5. The treatment assembly of claim 4, wherein:
the admission conduit second end is fixed to the casing via a bolt, said bolt
obturating the
admission conduit second end.
6. A treatment assembly according to claim 3, wherein:
the rotary enclosure communicates with an inside of said casing via at least
one outlet
nozzle through which centrifuged purified fluid passes, said nozzle being
oriented
substantially perpendicularly to a radius passing through an axis of rotation
of the rotary
enclosure, in such a way that the rotary enclosure is driven in rotation by a
reaction of the
centrifuged fluid coming out of the nozzle with respect to fluid contained in
the casing.
7. A treatment assembly according to claim 1, wherein:
the evacuation conduit is provided in the rotary distributor.
8. A treatment assembly according to claim 3, wherein:
receiving chambers for receiving fluid filtered by said filtering elements of
said filter and
fluid treated by said centrifuging device are provided in said single casing,
said chambers
being separated one from the other by a fluidtight partition wall.

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9. A treatment assembly according to claim 7, wherein:
the evacuation conduit is coaxial with an axis about which the rotary
distributor rotates.
10. A treatment assembly according to claim 3, wherein:
receiving chambers for receiving fluid filtered by said filtering elements of
said filter and
fluid treated by said centrifuging device are provided in said single casing,
said chambers
being separated one from the other by a fluidtight partition wall.
11. A fluid treatment assembly comprising:
casing means having a fluid to be filtered inlet, a filtered fluid outlet, and
a centrifuged
fluid outlet said inlet and said fluid outlet defining, in part, a first
internal fluid path
therebetween and said inlet and said centrifuged fluid outlet defining, in
part, a second
internal fluid path therebetween;
centrifuging means mounted rotatably in said second fluid path for
centrifuging a counter
current fluid having filtered impurities therein and for discharging the
centrifuged counter
current fluid to said centrifuged fluid outlet;
filter means having a filtering surface for filtering impurities from said
fluid to be filtered
as it travels along said first internal fluid path and for temporarily
accumulating on said
filtering surface the impurities removed from the fluid to be filtered; and
rotatable distributor means mounted to said filter means for periodically
isolating said
filtering surface from said first internal fluid path to permit a counter flow
of filtered fluid
to pass through said filtering surface to carry the filtered impurities along
said second
internal fluid path to said centrifuging means;
said first internal fluid path and said second internal path being
sufficiently isolated from

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one another by said rotatable distributor means to substantially prevent fluid
leakage from
said centrifuging means to said filter means as said fluid to be filtered
travels along said
first fluid path.
12. A fluid treatment assembly according to claim 11, further comprising
evacuation
means mounted axially within said casing means for defining an isolated fluid
path
extending axially between said filter means and said centrifuging means to
permit said
counterflow of filtered fluid to pass to said centrifuging means without
leakage to said
filtered fluid outlet.
13. A fluid treatment assembly according to claim 12, wherein said evacuation
means
is an internal evacuation conduit.
14. A fluid treatment assembly according to claim 13, wherein said
centrifuging
means includes a centrifuging enclosure in fluid communication with said
evacuation
conduit;
said centrifuging enclosure including nozzle means for discharging the
centrifuged fluid
toward said centrifuged fluid outlet and for causing said centrifuge enclosure
to rotate
about its longitudinal axis at a rapid rotational speed.
15. A fluid treatment assembly according to claim 14, wherein said rapid
rotational
speed is abut 6000 revolutions per minute.
16. A fluid treatment assembly according to claim 15, wherein said rotatable
distributor means includes motor means coupled to said filter means for
rotating it at a
slow rotational speed.
17. A fluid treatment assembly according to claim 16, wherein said slow
rotational
speed is between about 2 revolutions per minute and about 3 revolutions per
minute.

Description

CA 02203007 1997-04-17
1
ASSEMBLY FOR PROCESSING A FLUID BY FILTRATION AND
CENTRIFUGATION
A fluid treatment assembly is known, which assembly comprises, a filter
which itself comprises one or more filtering elements and a device for
periodically
cleaning each filtering element including on the one hand, a rotary
distributor
which periodically isolates one part of the filtering surface of each
filtering
element in order to enable the counter-current cleaning thereof, and on the
other
hand, an evacuation conduit for the cleaning fluid filled with the impurities
resulting from the cleaning, said treatment assembly further comprising a
centrifuging treatment device which itself comprises a rotary centrifuging
enclosure connected to a cleaning fluid admission conduit.
In this known treatment assembly, the centrifuging treatment device is
separated from the filter and is connected therewith via conduits external to
each of
said two treatment and filtering devices.
Such a treatment assembly is bulky, its cost price is high and it is subject
to
accidents, particularly where the external connection conduits are concerned.
It is the object of the present invention to overcome said drawbacks by
proposing to integrate, inside a single casing, the two devices which had been
separate up to now.
Thus according to the invention, the filtering element or elements and the
centrifuging enclosure are contained in a single casing, while the evacuation
conduit for the cleaning fluid filled with impurities issues directly into the
admission conduit of the rotary enclosure.
The advantageous following dispositions are also preferably adopted:
- one end of one of the evacuation conduits is fitted in one end of the other
of said two conduits, while the other end of the admission conduit is fixed on
said
single casing;
- said other end of the admission conduit is fixed to said casing via a bolt
which, at the same time, obturates said other end;
- the centrifuging enclosure communicates with the inside of the casing via
at least one outlet nozzle for the centrifuged fluid, which nozzle is oriented
substantially perpendicularly to a radius passing through the axis of rotation
of said
centrifuging enclosure, in such a way that said centrifuging enclosure is
driven in
rotation by the reaction of the fluid coming out of said outlet nozzle or
nozzles
with respect to the fluid contained in the casing;

CA 02203007 1997-04-17
2
- said evacuation conduit is provided in the rotaty distributor;
- receiving chambers for receiving the fluid filtered by the filtering
elements
of the filter and the fluid treated by the centrifuging treatment device, are
provided
in said single casing, said chambers being separated one from the other by a
fluidtight partition wall.
The invention offers the following main advantages : compactness of the
treatment assembly, reliability of said assembly, and reduced production costs
compared with the prior constructions.
The invention will be more readily understood and secondary characteristics
and their advantages will emerge from the following description of one example
of
embodiment.
It is to be understood that the description and drawings are only given by
way of indication and non-restrictively.
Reference will be made to the accompanying drawings, in which
- Figure 1 is an axial section of a treatment assembly according to the
invention,
- Figure 2 is a section along II-II of Figure 1, and
- Figure 3 is a section along III-III of Figure 1.
The fluid treatment assembly illustrated in the figures comprises a filter and
a centrifuging treatment device, both of them being contained in a single
casing 1
made up of two parts lA,1B, assembled by bolts.
The filter, which is contained in part lA of the casing, comprises:
- two transversal end walls 2, 3 between which is provided a stack 4 of
filtering elements 5, each one of which is shaped into a filtering disk 9,
with two
screens 6;
- a central axis 7;
- aligned bores 8, having the same diameter, and being coaxial to axis 7,
each bore belonging to one of the filtering disks 9, in tight contact with the
cylindrical external face 10 of a liner 11, which liner comprises a bore 15 co-
axial
to the axis 7;
- a central fluid distributor 12, mounted for rotation about axis 7, in tight
contact with a bore 13 provided in the intermediate wall 2, said wall being
itself
tightly assembled to parts lA and 1B of the casing;
- a U-section sector 14, provided in the fluid distributor 12, the periphery
16
of which bears tightly against the bore 15 of the liner 11, and which
communicates

CA 02203007 1997-04-17
3
with an evacuation conduit 17 provided in the fluid distributor 12, coaxial to
axis
7;
- a driving fork 18, situated at the axial end of the fluid distributor 12
opposite the intermediate wall 2;
- a receiving chamber for receiving the filtered fluid 19, which chamber is
provided inside the part lA of the casing, contains the stack 4 of filtering
elements
5 and is equipped with a connector 20 for the evacuation of the filtered
fluid;
- an admission chamber 21 for admitting the polluted fluid to be filtered,
said chamber being equipped with an admission connector 22 for admitting the
fluid to be filtered;
- a motor 23, in this particular example, a hydraulic motor, for driving the
fluid distributor 12 in rotation, said motor being fixed on the part lA of the
casing
and being equipped with a driving member 24 operationally coupled to the fork
18
for driving the fluid distributor 12 in rotation.
Each filtering element 5 comprises a plurality, counting twelve in the
embodiment illustrated in Figure 2, of angular sectors 41 which, through
orifices
provided in the liner 11 and in the bores 8, are adapted, successively, to
create a
communication between the inside space 27 defined by the parts of the two
screens
6 of the sector considered, and a conduit 26 which is provided in sector 14 of
the
20 fluid distributor 12 and which issues into the evacuation conduit 17, which
latter is
a blind conduit at the end of the fluid distributor 12 facing the wall 2.
The centrifuging treatment device is contained in part 1B of the casing and
comprises
- a central admission conduit 28 for admitting the fluid to be centrifuged, of
25 which one end 29 is constituted by an endpiece fitted in the open (non-
blind) end
of the evacuation conduit 17, while the other end 31 is constituted by a
female
thread for fixing in an obturating bolt 32; the bolt 32 itself constitutes the
end of a
plug 33 screwed 34 into a transversal end plate 35 which defines, in part 1B
of the
casing, a chamber 36 for receiving the centrifuged fluid, which chamber is
tightly
30 separated from the chamber 19 receiving the filtered fluid, by the
intermediate wall
2;
- a centrifuging enclosure 37 is mounted for rotating, via rings forming
smooth bearings, about axis 7, which axis 7 is also the axis of the admission
conduit 28 and of its external face 28A, said conduit therefore forming also a
rotary shaft for the centrifuging enclosure 37;

CA 02203007 1997-04-17
4
- orifices 38 creating a communication between the admission conduit 28
and the inside 39 of the enclosure 37.
A transversal bottom 40, which is perpendicular to the axis 7, defines the
part
of the centrifuging enclosure 37 which is placed in facing relationship to the
transversal wall 2. Said centrifuging enclosure 37 is totally isolated from
the
receiving chamber 36 receiving the centrifuged fluid except for the
communication
created by two outlet nozzles 43, which are substantially diametrically
opposite,
and whose outlet orifices are directed so as to be substantially perpendicular
to a
diameter passing through the axis 7, and in two opposite directions.
The treatment assembly works as explained hereinbelow.
The fluid to be treated, which is admitted into the admission chamber 21,
fills in the inner spaces 27 of all the sectors of the various filtering
elements 5, with
the exception of the space inside the sector 41 of each filtering element
which is
temporarily isolated from the other sectors 41 by the U-section sector 14
which is,
itself, in communication with the conduit 26.
This fluid to be filtered, which is contained in said spaces 27, flows through
the screens 6 of said sectors, depositing on the inner faces thereof, the
impurities
that it contains, and being received when cleared of its impurities, into the
receiving chamber 19 receiving the filtered fluid which is ready to be used
again.
Conversely, as regards the sectors 41 of the various filtering elements which
only communicate with the conduit 17, the pressure of the already filtered
fluid
which is contained in the chamber 19, causes part of said fluid to flow
through the
corresponding parts of the filtering screens 6, this enabling the impurities
which
have deposited on the inner faces of the screens to be periodically detached
therefrom and to be driven into the evacuation conduit 17. The function of the
motor 23 is to drive stepwise, sector 41 by sector 41, the distributor 12 in
rotation
so as to ensure that each angular sector 41 of the various filtering elements
is
periodically placed in communication with the evacuation conduit 17.
Said fluid filled with impurities is conveyed directly via the evacuation
conduit 17 and the admission conduit 28 towards the centrifuging enclosure 37,
where it is received therein 39 and where, by centrifuging, it is cleared of
its
impurities. The purified fluid is then evacuated out of the enclosure 37
through the
nozzles 43 and is received into the chamber 36 wherefrom it is released
towards an
application unit, via an outlet connector 44 provided in part 1B of the
casing.
It should be observed that the rotation of the centrifuging enclosure 37 is
induced by the effect of reaction, with respect to the fluid contained in the

CA 02203007 1997-04-17
enclosure 37, of the fluid escaping from the inside 39 of the enclosure 37
through
the conduits 42 of the nozzles 43. Said reaction effect is sufficient to drive
the
centrifuging enclosure in rotation at a rotation speed - of the order of 6000
rpms -
at which the centrifuging is effectively perfonmed. As a reminder, the speed
of
5 rotation reached by the motor 23 is around 2 to 3 rpms.
The advantage of the described embodiment resides in the compactness and
light weight of the assembly; in the elimination of any leaks from the
external
connections between Alter and centrifuging device, due to the elimination of
said
external connections; in the elimination of any risks of the external conduits
breaking up, as these conduits have also been eliminated; and finally, in the
obtained reduction of the assembly manufacturing costs..
It is understood that the invention is not limited to the embodiment of
filters
equipped with disks or pads as filtering elements, but also covers the case of
any
other filters such as, for example, those having cylindrical screens. The
motor 23,
which is advantageously a hydraulic type motor, may also, as a variant, be of
another type, such as electric. Finally, at least one nozzle 43 should be
provided,
and preferably an even number of diametrically opposite nozzles.
The invention finds an application in the treatment of lubricating oils for
"Diesel" type engines, or even in the purification of certain fuels used by
said
engines.
The invention is not limited to the described embodiment, and on the
contrary covers any variants that can be made thereto without departing from
its
scope or its spirit.

Dessin représentatif