Title of Invention

DEVICE FOR SEPARATING OIL FROM A DEAERATION OF AN OIL RESERVOIR

Abstract Device for separating oil from the de-aeration of an oil reservoir, which device comprises a line (3) for the de-aeration which is connected to the above-mentioned oil reservoir (1) with one far end and in which is provided a suction pump (4) for sucking in air, and whereby the other far end of the abovementioned line (3) is connected to a filter (7) which is provided in a chamber (8) which is connected to the abovementioned oil reservoir (1) by means of a return line (9), and which chamber (8) is provided with an outlet (10) to the environment, characterized in that a non-return valve (12) is provided in a the above-mentioned return line (9) which lets an air flow pass from the oil reservoir (1) to the chamber (8), and which prevents an air flow in the opposite direction, and whereby this non-return valve is provided with a small flow-back opening (16) which allows the oil which has been separated in the chamber (8) by the filter (7) to flow back to the oil reservoir (1).
Full Text WO 2006/047838 PCT/BE2005/000153
Device for separating oil from a de-aeration of an oil
reservoir.
The invention concerns a device for separating oil from
5 the de-aeration of an oil reservoir, which device is
of a known type which comprises a de-aeration line which
is connected with one far end to the above-mentioned
oil reservoir and in which is provided a suction pump
for sucking in air, and whereby the other far end of
10 the above-mentioned line is connected to a filter which
is provided in a chamber which is connected to the
above-mentioned oil reservoir by means of a return line,
and which chamber is provided with an outlet to the
environment.
15 An example of an oil reservoir which can be
equipped with such a device is for example the
crankcase of the gear box of an oil-free compressor.
The de-aeration of an oil reservoir, such as
20 the de-aeration of the crankcase of a
compressor, is full of oil aerosols, dispersion aerosols
as well as condensation aerosols. If the crankcase de-
aeration opened directly into the atmosphere, air with
oil could be sucked into the compressor. The
25 compressor and especially the cooling system could be
polluted by the oil. Hence the use of devices for
separating oil from the de-aeration of the crankcase.
CONFIRMATION COPY

WO 2006/047838 PCT/BE2005/000153
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In such known devices, air with oil-aerosols is
pumped through the above-mentioned line to the
filter by means of the above-mentioned suction
pump, where air and oil are separated. The
5 separated oil flows via the above-mentioned return
line back into the oil reservoir, where the purified
air is blown into the environment via the outlet.
From BE 1.009.008 is known such a device for separating
oil from the de-aeration of an oil reservoir, whereby
10 a certain flow rate of purified air is blown into the
environment through the above-mentioned outlet.
In practice, however, it appears that, despite the
presence of the above-mentioned filter, oil-polluted
air will flow through the above-mentioned outlet from the
15 oil reservoir into the ambient air.
Thorough research has proven that this phenomenon is
due to the fact that hot, rising oil vapours and/or
oil aerosol end up in the above-mentioned chamber via
20 the above-mentioned return line and pollute the purified
air again.
The present invention aims to remedy one or several
of the above-mentioned and other disadvantages and to
provide a simple device which makes it possible to
25 filter polluted air more efficiently and to separate
the oil therefrom.

WO 2006/047838 PCT/BE2005/000153

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To this end, the present invention concerns a device
of the above-mentioned type, whereby a non-return
valve is provided in the above-mentioned return line
which lets an air flow pass from the oil reservoir to
5 the chamber, and which prevents an air flow in the
opposite direction, and whereby this non-return valve
is provided with a small flow-back opening which
allows the oil which has been separated in the
chamber by the filter to flow back to the oil
10 reservoir.
Since the above-mentioned suction pump always sucks
in an air delivery from the above-mentioned oil
reservoir, there is always a slight underpressure in
the oil reservoir, as a result of which the above-
15 mentioned non-return valve is maintained in a closed
position.
In this closed position, it is still possible for oil
to flow back through the above-mentioned flow-back
opening from the chamber to the oil reservoir, but oil
20 vapours or oil aerosols are prevented from flowing from
the oil reservoir to the chamber and ending up in the
environment.
To this end, the flow-through section of the
25 above-mentioned flow-back opening is preferably
dimensioned such that it behaves as a closed channel.
which is constantly filled with oil flowing back from
the filter to the oil reservoir, and consequently it
will prevent vapours from escaping from the oil


WO 2006/047838 PCT/BE2005/000153
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reservoir via said flow-back opening. The oil which
flows back to the oil reservoir is sucked in as a result
of the slight underpressure prevailing in the oil
reservoir.
5 Should the above-mentioned suction pump fall out or
should the line get obstructed, the pressure in the oil
reservoir will rise, as a result of which the non-
return valve is forced into an open position, and the
air will flow from the oil reservoir via the return
10 line and the chamber, through the outlet into the
environment. This air is then brought into the
environment in a non-purified manner, but oil is
prevented from getting into the compressed air of the
oil-free compressor.
15
The above-mentioned non-return valve preferably
consists of a fixed part and a moving part, whereby
the above-mentioned flow-back opening is provided in
the moving part.
20
An advantage of such a non-return valve is that it has a
very simple construction and that it allows an oil flow
to easily pass from the chamber to the oil reservoir
through the above-mentioned flow-back opening in a
25 first, closed condition of use, and that it lets the
air flow pass from the oil reservoir to the chamber in a
second, opened condition of use.
In order to better explain the characteristics of the
30 invention, the following preferred embodiments of a



WO 2006/047838 PCT/BE2005/000153

5
device for separating oil from the de-aeration of an oil
reservoir are described with reference to the
accompanying drawings, in which:
figure 1 schematically represents an oil
5 reservoir upon which has been mounted a device
according to the invention for separating oil from
the de-aeration;
figure 2 represents the part indicated in figure 1
by F2 to a larger scale;
10 figure 3 represents a practical embodiment of a
device according to the invention;
figure 4 represents a section according to arrow IV-
IV in figure 3;
figure 5 represents a section according to arrow V-V
15 in figure 4.
Figure 1 schematically represents an oil reservoir 1, for
example a crankcase of the gear-wheel drive of an oil-
free compressor, which is provided with a device 2
according to the invention.
20 This device 2 comprises a line 3 for the de-aeration
which consists of two parts 3A and 3B, whereby the
first line part 3A is connected to the above-mentioned
oil reservoir 1 and whereby a suction pump 4 has
been provided between both parts 3A and 3B.
25
The above-mentioned suction pump 4 is in this case
formed of a venturi tube onto which the line 3 A is
connected in the constriction, whereas the line 3B is


WO 2006/047838 PCT/BE2005/000153
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connected to the outlet of the venturi tube, and
whereby a compressed air line 5 is connected to the
inlet of the venturi tube.
The compressed air line 5 is part of a compressed air
5 network which is not represented in the figures and
which is fed with the compressed air of the
compressor or another compressed air source. In this
compressed air line is in this case mounted a restrictor
or pressure regulator 6, upstream the ejector.
10 An advantage of the use of such an ejector, is that it
has no moving parts and thus is not liable to wear.
The second line part 3B of the line 3 connects the
pressure side of the above-mentioned suction pump 4 to
15 a standing, annular filter 7 which has been mounted
vertically and which is made of a spongy material
which collects oil in the form of an aerosol from
the air, flowing from the inside to the outside
through the filter wall, and in which fine drops stick
20 together, such that larger oil drops are formed which
trickle down along the outside of the filter 7.
The above-mentioned filter 7 is provided in a chamber 8
which is connected to the above-mentioned oil reservoir
25 1 by means of a return valve 9 and which is also
provided with an outlet 10 to the environment.
As is represented in greater detail in figure 2, the
above-mentioned return line 9 consists of two parts 9A

WO 2006/047838 PCT/BE2005/000153
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and 9B, more particularly a first part 9A which is
connected to the above-mentioned chamber 8 and a
second part 9B which is connected to the above-
mentioned oil reservoir 1, which are connected to each
5 other by means of a flanged joint 11.
According to the invention, a non-return valve 12 is
provided in the above-mentioned return line 9 which
mainly consists of a fixed part 13 which is clamped
10 between the above-mentioned flanged joint 11, either or
not partially, and which provides for a sealing of said
flanged joint; and cf a moving part 14 which is hinge-
mounted to the above-mentioned fixed part 13.
In the above-mentioned fixed part 13 is provided a first
15 opening 15 which can be sealed by means of the above-
mentioned moving part 14.
In the moving part 14 is provided a small flow-
back opening 16 which is smaller than the above-
20 mentioned first opening 15 in the fixed part 13 of the
non-return valve 12, and which, when the non-return
valve 12 is closed, always forms a passage from the
chamber 8 to the oil reservoir 1.
The working of the device 2 according to the invention
25 is very simple and as follows.
When the ejector is being fed by the compressed air
line 5 with a flow rate QE of compressed air via the
pressure regulator 6, a certain flow rate Ql of oil-



WO 2006/047838 PCT/BE2005/000153
8
polluted air will be sucked over the first part 3A of
the line 3 from the oil reservoir 1.
The dimensions of the device have been selected such
that this flow rate Ql is a little larger than the
5 normal crankcase de-aeration flow rate QS, namely the
flow rate which is brought into the oil reservoir 1 via
components of the compressor and especially via the
sealings around the rotor shaft.
As a result, a slight and almost constant
10 underpressure will constantly prevail in the oil
reservoir 1.
As a result, the moving part 14 of the non-return valve
12 is sucked against the fixed part 13 so that it is
situated in its first, closed condition of use.
15
In the ejector, the oil-polluted air is mixed with the
compressed air, and the common flow rate QE+Q1 is sent
via the second part 3B of the line 3 through the
filter 7, after which the purified air escapes via the
20 outlet 10 into the environment, namely at a flow rate
which is equal to QE+Q1.
The oil drops which are formed in the filter 7 trickle
down the filter 7 and are carried back into the oil
reservoir 1 by the gravitational force over the
25 return line 9 and through the flow-back opening 16 in the
moving part 14 of the non-return valve 12 . The
prevailing underpressure in the oil reservoir 1 also


WO 2006/047838 PCT/BE2005/000153
9
helps the oil flow through the flow-back opening 16.
The dimensions of the above-mentioned flow-back
opening 16 in the moving part 14 are hereby made such
that this flow-back opening 16 is constantly filled
5 with oil which flows back from the filter 7 to the oil
reservoir 1, such that this flow-back opening 16 is
sealed by the flow of oil which flows back, as a result
of which air with oil vapours cannot get into the
chamber 8 via this flow-back opening 16.
10
When the de-aeration of the crankcase fails, for example
because the compressed air in the compressed air line
5 falls out, a slight overpressure will be created
in the oil reservoir 1 as a result of the crankcase
15 de-aeration flow rate QS leaking out to the oil
reservoir 1, which overpressure forces the above-
mentioned non-return valve 12 in a second, open
position of use, as is represented by means of the
dashed line in figure 2, such that polluted air is
20 discharged into the environment via the return line 9
and the chamber 8 along the outlet 10.
Figure 3 represents a practical embodiment of a device
2 according to the invention, whereby parts with the
25 same function have the same figures of reference as in
the preceding figures.
In this embodiment, the filter 7 is provided in a
filter housing 17 which is provided against the oil
30 reservoir 1 and forms the chamber 8, whereby the filter

WO 2006/047838 PCT/BE2005/000153
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housing 17 is sealed by a removable filter lid 18 in
which the above-mentioned suction pump 4 in the
shape of a venturi tube has been provided, and
whereby the line parts 3A and 3B are formed of
5 inner, connecting bores in the filter housing 17 and
in the filter lid 18 respectively.
The above-mentioned non-return valve 12 is in this case
made of a sealing material, such as for example an
elastomer such as rubber, and forms a sealing between
10 the filter housing 17 and the oil reservoir 1 which is
clamped in a recess between both parts.
This non-return valve 12 is provided with a second
opening 19 which forms a passage for the air which is
sucked in from the oil reservoir 1 via the above-
15 mentioned line 3A by the suction pump 4, and which is
forced out via the line 3B in the filter housing 17,
through the filter 7 and the outlet 10.
The oil which is separated by the filter 7 is collected
at the bottom of the filter housing 17 and is carried
20 back to the oil reservoir 1 via the return line 9 and
the flow-back opening 16 in the non-return valve 12 in
this return line 9.
As is shown in the detailed figures 4 and 5 of the
above-mentioned non-return valve 12, the above-
25 mentioned moving part 14 is in this case made in one
piece with the above-mentioned fixed part 13.

WO 2006/047838 PCT/BE2005/000153
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It is clear that the above-mentioned suction pump 4
can be made in different ways, in the shape of
several types of pumps, such that the presence of a
compressed air line is not necessary.
5 It is also clear that the presence of a pressure
regulator 6 in the compressed air line 5 is not strictly
necessary.
According to the invention, the above-mentioned filter
can be made in many ways and it is not restricted to a
10 standing annular filter as described above.
It is clear that the above-mentioned first opening 15 can
be provided in the above-mentioned fixed part 13
instead of in the moving part 14.
Naturally, a device according to the invention cannot
15 merely be applied to the crankcase of an oil-free
compressor, but it can also be applied to other oil
reservoirs.
The present invention is by no means limited to the
embodiment described above and represented in the
20 accompanying drawings; on the contrary, such a device
for separating oil can be made in all sorts of variants
while still remaining within the scope of the
invention.

WO 2006/047838 PCT/BE2005/000153



12
Claims.
1.- Device for separating oil from the de-
aeration of an oil reservoir, which device comprises a
5 line (3) for the de-aeration which is connected to the
above-mentioned oil reservoir (1) with one far end
and in which is provided a suction pump (4) for sucking
in air, and whereby the other far end of the above-,
mentioned line (3) is connected to a filter (7) which is
10 provided in a chamber (8) which is connected to the
above-mentioned oil reservoir (1) by means of a return
line (9) , and which chamber (8) is provided with an
outlet (10) to the environment, characterised in that a
non-return valve (12) is provided in the above-
15 mentioned return line (9) which lets an air flow pass
from the oil reservoir (1) to the chamber (8) , and which
prevents an air flow in the opposite direction, and
whereby ' this non-return valve is provided with a small
flow-back opening (16) which allows the oil which
20 has been separated in the chamber (8) by the filter
(7) to flow back to the oil reservoir (1) .

25

2.- Device according to claim 1, characterised in that
the above-mentioned non-return valve (12) mainly
consists of a fixed part (13) and a moving part (14),
whereby at least one first opening (13) is provided in
the above-mentioned fixed part which can be sealed by
means of the above-mentioned moving part (14) .

WO 2006/047838 PCT/BE2005/000153
13
3.- Device according to claim 2, characterised in that
the above-mentioned flow-back opening (16) has been
provided in the moving part (14) .
5 4.- Device according to claim 2, characterised in that
the above-mentioned non-return valve (12) is made in one-
piece .
5.- Device according to claim 2, characterised in that
the above-mentioned non-return valve (12) is made out
10 of a sealing material.
6.- Device according to claim 5, characterised in that
the above-mentioned non-return valve (12) is made in
the form of a sealing.
7.- Device according to claim 6, characterised in that
15 the above-mentioned return line (9) consists of a first
part (9A) which is connected to the above-mentioned
chamber (8) and a second part (9B) which is connected to
the above-mentioned oil reservoir (1) ; and in that the
above-mentioned first and second part (9A and 9B) are
20 connected to each other by means of a flanged joint
(11) in between which the above-mentioned non-return
valve (12) has been provided.
8.- Device according to claim 2, characterised in that
25 in the above-mentioned fixed part (13) is provided a
second opening (19) , next to the above-mentioned moving
part (14) .

WO 2006/047838 PCT/BE2005/000153
14
9.- Device according to claim 8, characterised in that
the above-mentioned second opening (19) is provided
between the line (3) and the above-mentioned oil
reservoir (1) .
5
10.- Device according to claim 1, characterised in
that the dimensions of the above-mentioned flow-back
opening (16) are such that, when in use, this flow-back
opening (16) is constantly filled with oil which is
10 separated from the filter (7) and which flows back to
the oil reservoir (1) via this flow-back opening (16) .

Device for separating oil from the de-aeration of an oil reservoir, which device comprises
a line (3) for the de-aeration which is connected to the above-mentioned oil reservoir (1)
with one far end and in which is provided a suction pump (4) for sucking in air, and
whereby the other far end of the abovementioned line (3) is connected to a filter (7)
which is provided in a chamber (8) which is connected to the abovementioned oil
reservoir (1) by means of a return line (9), and which chamber (8) is provided with an
outlet (10) to the environment, characterized in that a non-return valve (12) is provided in
a the above-mentioned return line (9) which lets an air flow pass from the oil reservoir (1)
to the chamber (8), and which prevents an air flow in the opposite direction, and whereby
this non-return valve is provided with a small flow-back opening (16) which allows the
oil which has been separated in the chamber (8) by the filter (7) to flow back to the oil
reservoir (1).

Documents:

01200-kolnp-2007-abstract.pdf

01200-kolnp-2007-claims.pdf

01200-kolnp-2007-correspondence others 1.1.pdf

01200-kolnp-2007-correspondence others 1.2.pdf

01200-kolnp-2007-correspondence others 1.3.pdf

01200-kolnp-2007-correspondence others 1.4.pdf

01200-kolnp-2007-correspondence others 1.5.pdf

01200-kolnp-2007-correspondence others.pdf

01200-kolnp-2007-description complete.pdf

01200-kolnp-2007-drawings.pdf

01200-kolnp-2007-form 1.pdf

01200-kolnp-2007-form 2.pdf

01200-kolnp-2007-form 3.pdf

01200-kolnp-2007-form 5.pdf

01200-kolnp-2007-gpa.pdf

01200-kolnp-2007-international publication.pdf

01200-kolnp-2007-international search report.pdf

01200-kolnp-2007-pct request 1.1.pdf

01200-kolnp-2007-pct request.pdf

01200-kolnp-2007-priority document 1.1.pdf

01200-kolnp-2007-priority document.pdf

1200-KOLNP-2007-ABSTRACT 1.1.pdf

1200-KOLNP-2007-ABSTRACT.pdf

1200-KOLNP-2007-CANCELLED PAGES 1.1.pdf

1200-KOLNP-2007-CANCELLED PAGES.pdf

1200-KOLNP-2007-CLAIMS 1.1.pdf

1200-KOLNP-2007-CLAIMS.pdf

1200-KOLNP-2007-CORRESPONDENCE 1.7.pdf

1200-kolnp-2007-CORRESPONDENCE OTHERS 1.6.pdf

1200-KOLNP-2007-DESCRIPTION (COMPLETE) 1.1.pdf

1200-KOLNP-2007-DESCRIPTION (COMPLETE).pdf

1200-KOLNP-2007-DRAWINGS 1.1.pdf

1200-KOLNP-2007-DRAWINGS.pdf

1200-KOLNP-2007-FORM 1.1.1.pdf

1200-KOLNP-2007-FORM 1.pdf

1200-KOLNP-2007-FORM 13.pdf

1200-kolnp-2007-FORM 18.pdf

1200-KOLNP-2007-FORM 2.1.1.pdf

1200-KOLNP-2007-FORM 2.pdf

1200-KOLNP-2007-FORM 3.pdf

1200-KOLNP-2007-FORM 5.pdf

1200-KOLNP-2007-OTHERS.pdf

1200-KOLNP-2007-PETITION UNDER RULE 137.pdf

1200-KOLNP-2007-REPLY TO EXAMINATION REPORT.pdf

abstract-01200-kolnp-2007.jpg


Patent Number 242548
Indian Patent Application Number 1200/KOLNP/2007
PG Journal Number 36/2010
Publication Date 03-Sep-2010
Grant Date 31-Aug-2010
Date of Filing 05-Apr-2007
Name of Patentee ATLAS COPCO AIRPOWER, NAAMLOZE VENOOTSCHAP
Applicant Address BOOMSESTEENWEG 957, B-2610 WILRIJK
Inventors:
# Inventor's Name Inventor's Address
1 VAN DEN BERGHE, PIETER PARTRIJZENLAAN 18, B-9470 DENDERLEEUW
PCT International Classification Number F01M 13/04
PCT International Application Number PCT/BE2005/000153
PCT International Filing date 2005-11-03
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2004/0542 2004-11-08 Belgium