VORTEX TUBE, VENTILATION SYSTEM AND ELEVATOR
FIELD OF THE INVENTION
[0001] The invention relates to a vortex tube, a ventilation system and an
elevator, wherein the interior to be ventilated is the interior of a car, a hoistway or a
5 machine room of an elevator, for instance.
BACKGROUND OF THE INVENTION
[0002] Elevators typically have one or more cars traveling vertically in a
hoistway. The conditions inside the car are continuously controlled so as to ensure
healthy and comfortable experience. This usually involves ventilating the interior
10 with fresh air the temperature of which may be adjustable. Elevator interiors are
typically demanding spaces to be ventilated, particularly with regard to efficiency
with minimal space consumption, noise level and reliability of the ventilating
equipment. The interior of an elevator car for instance, should be ventilated with a
simple, lightweighted and compact system so that the car can utilize maximally
15 efficiently its volume as transport space and the moving masses are minimized. The
ventilation system should be quiet to ensure good ride comfort, as well as maintained
stable and in operation in all situations in order to ensure uninterrupted passenger
air supply and comfort. The ventilation system should also be unlikely to malfunction,
have low power consumption and it should be quick and easy to install and service.
20 [0003] A drawback of ventilation systems and equipment for elevator use has
been that they have not been very compact, efficient and quiet. Vortex tubes, also
known as Ranque-Hilsch vortex tubes, utilizing so called vortex tube effect are known
components which intake air flow and separate it to two air flows of different
temperature, namely to a hot air flow and a cold air flow. Use of a vortex tube as part
25 of a ventilation system arranged to ventilate an interior has been proposed, but found
to have room for improvement in terms of as efficiency of the vortex tube to separate
the intaken air flow into hot and cold air flows.
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BRIEF DESCRIPTION OF THE INVENTION
[0004] The object of the invention is to introduce a new vortex tube, a ventilation
system and an elevator. An object is particularly to introduce a solution by which one
or more of the above defined problems of prior art and/or problems discussed or
5 implied elsewhere in the description can be solved.
[0005] It is brought forward, inter alia, a new vortex tube, a ventilation system
and an elevator, which has an improved efficiency (COP) to separate an intaken air
flow into hot and cold air flows with a big temperature difference.
[0006] It is brought forward a new vortex tube, in particular for a ventilation
10 system, the vortex tube comprising a first end provided with a first outlet; a second
end provided with a second outlet; and a vortex generating chamber between the first
end and the second end; and an air inlet leading from a side of the vortex tube into
the vortex generating chamber for guiding air flow into the vortex generating
chamber; and a first flow passage between the vortex generating chamber and the
15 first outlet; and a second flow passage between the first flow passage and the second
outlet; wherein the vortex tube is arranged to guide air fed into the air inlet to flow
via the air inlet into the vortex generating chamber, and from it into the first flow
passage, the vortex tube being arranged to discharge a portion of the air from the
vortex tube via the first outlet at the first end, and to guide a portion of the air to flow
20 in the first flow passage back from the first end as backflow; the backflow being
arranged to flow into the second flow passage to be discharged from the vortex tube
via the second outlet. The vortex tube comprises one or more air guides disposed
inside the vortex tube downstream of the vortex generating chamber for increasing
laminarity of air flow downstream of the vortex generating chamber, wherein one or
25 more of said air guides is an air guide comprising plurality of openings, through which
openings air can flow. With this solution one or more of the above mentioned objects
can be achieved. The vortex tube is usable for separating an intaken air flow into hot
and cold air flows utilizing a so called vortex tube effect. The one or more air guides,
due to being able to substantially increase laminarity of air flow downstream of the
30 vortex generating chamber, increase thermal efficiency of the vortex tube, which is an
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advantageous effect in many applications, such as a ventilation system of an elevator
where efficiency is one important goal, amongst other important goals to be satisfied
by the ventilation system such as compactness, lightness, noise level and reliability
which are also, at least satisfactorily, facilitated by utilization of a vortex tube.
5 [0007] Preferable further details are introduced in the following, which further
details can be combined with the vortex tube individually or in any combination.
[0008] In a preferred embodiment, air passing to the air guide is arranged to split
into plurality of openings thereof and pass through them to the other side of the air
guide.
10 [0009] In a preferred embodiment, the one or more air guides are arranged to
reduce Reynolds number of air flow in the vortex tube downstream of the vortex
generating chamber to be less than 2000.
[0010] In a preferred embodiment, said openings extend parallel to each other
through the air guide.
15 [0011] In a preferred embodiment, each said air guide is a perforated plate or a
grille.
[0012] In a preferred embodiment, each said opening is a through-hole.
[0013] In a preferred embodiment, the air guide comprises more than 30 of said
openings, preferably more than 50 of said openings. High number of openings
20 facilitates efficiency of reduction of turbulence and thereby increases laminarity of
air flow passing through the air guide. The density of said openings is preferably more
than 30 of said openings, more preferably more than 50 of said openings per square
cm of the cross section of the flow passage wherein the air guide is disposed.
[0014] In a preferred embodiment, the air guide fills a complete cross section of
25 a flow passage downstream of the vortex generating chamber.
[0015] In a preferred embodiment, each opening has depth/width ratio (d/w)
larger than 1, in particular wherein the width (w) is measured in transverse direction
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of the flow passage and depth (d) in axial direction of the flow passage wherein the
air guide in question is disposed.
[0016] In a preferred embodiment, the openings extend through the air guide in
axial direction of the flow passage wherein the air guide in question is disposed.
5 [0017] In a preferred embodiment, the vortex tube comprises one or more,
preferably two, of said air guides disposed in the first flow passage.
[0018] In a preferred embodiment, the vortex tube comprises one or more,
preferably two, of said air guides disposed in the second flow passage.
[0019] In a preferred embodiment, air is guided to swirl in the vortex generating
10 chamber along the inner surface of the vortex generating chamber.
[0020] In a preferred embodiment, a hub is inserted in the vortex generating
chamber around which air arriving through the air inlet is arranged to swirl in the
vortex generating chamber. The hub preferably is formed by a part inserted into the
vortex generating chamber. Said part is preferably removably insertable into the
15 vortex generating chamber.
[0021] In a preferred embodiment, the second flow passage extends into the
vortex generating chamber.
[0022] In a preferred embodiment, said air guides disposed in the second flow
passage include an air guide or air guides, disposed in a passage of the
20 aforementioned hub, said passage of the aforementioned hub forming a part of the
second flow passage. The hub preferably is formed by a part inserted into the vortex
generating chamber. Said part is preferably removably insertable into the vortex
generating chamber.
[0023] In a preferred embodiment, the central hub comprises tangential holes
25 leading from outside the central hub to inside the central hub. The tangential holes in
particular converge tangentially with a circular interior of the hub.
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[0024] In a preferred embodiment, the one or more air guides disposed in the first
flow passage are arranged to reduce Reynolds number of air flow in the first flow
passage to be less than 2000, in particular at a point, which is located between an air
guide and the first opening and/or at a point which is located between an air guide
5 and the vortex generating chamber said point being at the center of the of the cross
section of the first flow passage i.e. at a point of the aforementioned backflow.
[0025] In a preferred embodiment, it comprises an air valve for controlling
discharge of air from the first flow passage through the first outlet, in particular at the
first end.
10 [0026] In a preferred embodiment, the air valve comprises a central plug portion
for blocking flow of air at the center of the cross section of the first flow passage
through the valve, one or more peripheral air passages being formed beside the
central plug portion, whereby the air valve is arranged to guide a portion of air
through the one or more peripheral air passages for being discharged from the vortex
15 tube via the first outlet, and a portion of the air to flow at the center of the of the cross
section of the first flow passage back from the first end as backflow.
[0027] In a preferred embodiment, said one or more air guides disposed in the
first outlet portion are in the first flow passage between the vortex generating
chamber and the valve.
20 [0028] In a preferred embodiment, the hub comprises a central opening, in
particular concentric with the vortex generating chamber and the first and second
flow passage, for receiving the backflow of air, which backflow returns from the first
end inside the first flow passage and flows at the centre of the first flow passage, and
for guiding said backflow to flow into the second flow passage.
25 [0029] In a preferred embodiment, the vortex generating chamber has a circular
or at least substantially circular cross section.
[0030] In a preferred embodiment, the vortex tube comprises phase change
material forming one or more of the following:
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at least a portion of the inner wall surface of the vortex generating
chamber, along which inner wall surface of the vortex generating chamber air is/can
be arranged to flow;
at least a portion of the inner wall surface of the first flow passage, along
5 which inner wall surface of the first flow passage air is/can be arranged to flow;
at least portion of the inner wall surface of the second flow passage, along
which inner wall surface of the second flow passage air is/can be arranged to flow.
Phase changing ability of the material enhances ability of the material to absorb
energy. The advantage of the phase change material is that enhances energy transfer
10 within the vortex tube so that COP value (coefficient of performance) of the vortex
tube increases. By use of PCM excessive thermal losses of the vortex tube are also
avoided. Phase change material facilitates one or more of these objects and
advantages also if the air guides are different in structure or differently positioned
than described above, or even absent completely. Accordingly, the vortex tube
15 comprising phase change material as defined above can form an invention
independent on features related to the air guides.
[0031] In a preferred embodiment, the vortex tube comprises one or more body
parts coated internally with a phase change material, the thickness of the coating
preferably being 0.5-1.0 mm.
20 [0032] In a preferred embodiment, the aforementioned phase change material is
solid-solid -phase change material.
[0033] In a preferred embodiment, the aforementioned phase change material
comprises salt hydrates (MxNyH2O).
[0034] In a preferred embodiment, the internal diameter of the first flow passage
25 is between 5 and 15 mm, more preferably between 5 and 10 mm. Preferably,
moreover, a length L of the vortex tube is between 100 and 200 mm, more preferably
between 120 and 150 mm wherein the length is the distance in axial direction x
between the second outlet and the one or more peripheral air passages. The ratio
length L / internal diameter of the first flow passage is preferably between 10 and 30,
30 preferably between 15 and 20, such as 17-18.
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[0035] In a preferred embodiment, air is guided to pass in the first flow passage
towards the first end along the inner surface of the first flow passage, in particular
swirling, and back from the first end as backflow towards the second end at the center
of the of the cross section of first flow passage.
5 [0036] It is also brought forward a new ventilation system arranged to ventilate
an interior the ventilation system comprising an air supply duct; and a device for
feeding air into the air supply duct; and a vortex tube as defined anywhere above,
wherein a first outlet duct is connected to the first outlet opening and the interior for
guiding air from the first outlet opening to the interior and/or a second outlet duct is
10 connected to the second outlet opening and the interior for guiding air from the
second outlet opening to the interior. With this solution one or more of the above
mentioned objects can be achieved such that air, or at least part of it, which air exits
a vortex tube is usable for heating and/or cooling the interior to be ventilated.
[0037] Preferable further details of the ventilation system have been introduced
15 earlier above as well as in the following, which further details can be combined with
the ventilation system individually or in any combination.
[0038] In a preferred embodiment, the first outlet duct is connected to the
interior to be ventilated via an air distribution device comprising one or more
openings through which air from the first outlet duct can flow into the interior to be
20 ventilated.
[0039] In a preferred embodiment, the second outlet duct is connected to the
interior to be ventilated via an air distribution device comprising one or more
openings through which air from the second outlet duct can flow into the interior to
be ventilated.
25 [0040] In a preferred embodiment, the ventilation system comprises a valve,
preferably for example in one of said first and second outlet duct, for controlling air
flow between the vortex tube and the interior to be ventilated.
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[0041] In a preferred embodiment, the valve is connected to a thermostat. The
thermostat preferably is arranged to sense temperature of the interior to be
ventilated or the temperature of air to be guided therein. The thermostat then
preferably comprises a sensor head located in the interior to be ventilated or in a
5 location via which air is guided to the interior to be ventilated. The valve is
particularly controllable by the thermostat.
[0042] In a preferred embodiment, a branch duct is connected to the valve and
the valve is arranged to adjust how big proportion of the flow from the vortex tube
flows into the branch duct.
10 [0043] In a preferred embodiment, the aforementioned branch duct leads to a
space outside the interior to be ventilated.
[0044] In a preferred embodiment, the air supply duct is connected to the air inlet
of the vortex tube.
[0045] In a preferred embodiment, the aforementioned device for feeding air into
15 the air supply duct arranged to feed pressurized air into the air supply duct. It is
preferably arranged to intake air and elevate its pressure.
[0046] In a preferred embodiment, the aforementioned device for feeding air into
the air supply duct is an air compressor.
[0047] In a preferred embodiment, the aforementioned device for feeding air into
20 the air supply duct is arranged to intake air from a source outside the interior to be
ventilated, such as hoistway, the ventilation system of the building, or exterior of the
building, for instance.
[0048] It is also brought forward a new elevator comprising an interior to be
ventilated and a ventilation system as defined anywhere above arranged to ventilate
25 said interior. With this solution one or more of the above mentioned objects can be
achieved. A ventilation system utilizing the vortex tube is advantageous particularly
in context of an elevator where compactness, lightness, efficiency, reliability and
small amount of noise are important properties of a ventilation system.
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[0049] Preferable further details of the elevator have been introduced earlier
above as well as in the following, which further details can be combined with the
elevator individually or in any combination.
[0050] In a preferred embodiment, the elevator comprises an elevator car
5 arranged to be moved vertically in a hoistway between vertically displaced landings.
[0051] In a preferred embodiment, the interior to be ventilated is the interior of
an elevator car of the elevator, a machine room of the elevator, a hoistway of the
elevator or a control cabinet of the elevator.
[0052] In a preferred embodiment, the elevator is a passenger elevator
10 comprising an elevator car comprising said interior to be ventilated. The interior is
preferably closable by a door. In this kind of context use of the ventilation system as
defined in particularly advantageous.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] In the following, the present invention will be described in more detail by
15 way of example and with reference to the attached drawings, in which
Figure 1a illustrates an embodiment a vortex tube.
Figure 1b illustrates a cross section A-A of the vortex tube of Figure 1.
Figure 2a illustrates a first preferred embodiment of the air guide of Figure 1 and its
position in the vortex tube as viewed in axial direction of the vortex tube.
20 Figure 2b illustrates a side view of the air guide of Figure 2a.
Figure 3a illustrates a second preferred embodiment of the air guide of Figure 1 and
its position in the vortex tube as viewed in axial direction of the vortex tube.
Figure 3b illustrates a side view of the air guide of Figure 3a.
Figure 4 illustrates an embodiment of a ventilation system comprising a vortex tube
25 as illustrated in Figure 1.
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Figure 5 illustrates an embodiment of an elevator comprising a ventilation system as
illustrated in Figure 4.
The foregoing aspects, features and advantages of the invention will be apparent from
the drawings and the detailed description related thereto.
5 DETAILED DESCRIPTION
[0054] Figure 1 illustrates an embodiment a vortex tube 5 comprising a first end
5a provided with a first outlet 7 and a second end 5b provided with a second outlet 8.
The vortex tube 5 comprises a vortex generating chamber (6a) between the first end
and the second end 5a,5b, and between the aforementioned outlets 7, 8 provided in
10 said ends 5a,5b. The vortex tube 5 moreover comprises an air inlet 9 leading from a
side of the vortex tube 5 into the vortex generating chamber 6a for guiding air flow
into the vortex generating chamber 6c and a first flow passage 6b between the vortex
generating chamber 6a and the first outlet 7 as well as a second flow passage 6c
between the first flow passage 6b and the second outlet 8.
15 [0055] The vortex tube 5 is arranged to guide air fed into the air inlet 9 to flow via
the air inlet 9 into the vortex generating chamber 6a, and from it into the first flow
passage 6b, the vortex tube 5 being arranged to discharge a portion of the air from
the vortex tube 5 via the first outlet 7 at the first end 5a, and to guide a portion of the
air to flow in the first flow passage 6b back from the first end 5a as backflow; the
20 backflow being arranged to flow into the second flow passage 6c to be discharged
from the vortex tube 5 via the second outlet 8.
[0056] The vortex tube 5 comprises one or more air guides 10,10’ disposed inside
the vortex tube 5 downstream of the vortex generating chamber 6c, in particular in
the first flow passage 6b and/or in the second flow passage 6c for increasing
25 laminarity of air flow downstream of the vortex generating chamber 6c, in particular
for reducing Reynolds number of the air flow. Each said air guide 10,10’ is an air guide
10,10’ comprising plurality of openings 11,11’, through which openings 11,11’ air can
flow. A first preferred embodiment of the air guide 10 is illustrated in Figures 2a and
2b and a second preferred embodiment of the air guide 10’ is illustrated in Figures 3a
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and 3b. As illustrated in Figures 1,2a and 3a, the air guide 10,10’ preferably fills the
complete cross section of a flow passage 6b,6c downstream of the vortex generating
chamber 6c.
[0057] Each said flow passage 6b,6c has an axial direction x. The openings 11,11’
5 extend through the air guide 10,10’ in axial direction x of the flow passage 6b,6c
wherein the air guide 10,10’ in question is disposed.
[0058] Air passing to the air guide 10,10’ is arranged to split into plurality of
openings 11,11’ thereof and pass through them to the other side of the air guide
10,10’. The guide 10,10’ is such that said openings 11,11’ extend parallel to each other
10 through the air guide 10,10’.
[0059] In the preferred embodiment of Figure 2, said air guide 10 is a perforated
plate. In this case, each said opening 11 is a through-hole preferably punched or
drilled in a plate, such as a metal or plastic plate or composite material plate. The
perforated plate can alternatively be made by molding.
15 [0060] In the preferred embodiment of Figure 3, said air guide 10’ is a grille. In
this case, preferably each said opening 11 is a through-hole bordered by bars.
[0061] In the preferred embodiments of Figure 2 and 3 each opening has
depth/width ratio d/w greater than 1, wherein the width w is measured in transverse
z direction of the flow passage and depth d in axial direction x of the flow passage
20 6b,6c wherein the air guide 10,10’ in question is disposed. This facilitates efficiency
of reduction of turbulence and thereby increases laminarity of air flow passing
through the air guide 10,10’. In the preferred embodiments illustrated, said axial
direction x of the flow passages 6a and 6b equals the axial direction x of the vortex
tube 5.
25 [0062] Preferably, the number of said openings 11,11’ is great. Particularly,
preferably the air guide 10,10’ comprises more than 30 of said openings 11,11’
preferably more than 50 of said openings. This facilitates efficiency of reduction of
turbulence and thereby increases laminarity of air flow passing through the air guide
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10,10’. The density of said openings is preferably more than 30 of said openings
11,11’, more preferably more than 50 of said openings 11,11’ per square cm of the
cross section of the flow passage 6b,6c wherein the air guide 10,10 is disposed.
[0063] In the preferred embodiment illustrated in Figure 1, the vortex tube 5
5 comprises two of said air guides 10,10’ disposed in the first flow passage 6b. This
facilitates efficiency of reduction of turbulence and thereby increases laminarity of
air flow passing in the first flow passage 6b.
[0064] In the preferred embodiment illustrated in Figure 1, the vortex tube 5
comprises two of said air guides 10,10’ disposed in the second flow passage 6c. This
10 facilitates efficiency of reduction of turbulence and thereby increases laminarity of
air flow passing in the second flow passage 6c. A laminar flow is characterized by the
parallel flow of fluid layers. This parallel flow between layers can be increased by
reducing the disruption between layers.
[0065] In the preferred embodiment illustrated in Figure 1, the one or more air
15 guides 10,10’ are arranged to reduce Reynolds number of air flow in the vortex tube
5 downstream of the vortex generating chamber 6c to be less than 2000. More
specifically, the one or more air guides 10,10’ disposed in the first flow passage 6b are
arranged to reduce Reynolds number of air flow in the first flow passage 6b to be less
than 2000, in particular at a point p1, which is located between an air guide 10,10’
20 and the first opening 7 and/or at a point p2 which is located between an air guide
10,10’ and the vortex generating chamber 6c said point p2 being at the center of the
of the cross section of first flow passage 6b i.e. at a point of the aforementioned
backflow.
[0066] The vortex tube 5 functions so that air is guided to swirl in the vortex
25 generating chamber 6a along the inner surface of the vortex generating chamber 6a.
[0067] For facilitating separation of air flow arriving from the vortex generating
chamber 6a to the first end 5a to a portion (hot portion) to exit the vortex tube 5 via
the first outlet 7 and a portion (cold portion) to exit the vortex tube 5 via the second
opening 8, the vortex tube 5 comprises at the first end 5a thereof an air valve 13 for
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controlling discharge of air from the first flow passage 6b through the first outlet 7.
The air valve 13 comprises a central plug portion 13a for blocking flow of air flow at
the center of the cross section of the first flow passage 6b through the valve 13. One
or more peripheral air passages 13b are formed beside the central plug portion 13a,
5 whereby the air valve 13 is arranged to guide a portion (hot portion) of air through
the one or more peripheral air passages 13b for being discharged from the vortex
tube 5 via the first outlet 7, as well as to guide a portion (cold portion) of the air to
flow at the center of the of the cross section of first flow passage 6b back from the first
end 5a as backflow. Said one or more air guides disposed in the first outlet portion 6a
10 are in the first flow passage 6b between the vortex generating chamber 6a and the
valve 13.
[0068] The separation is meant to work such that when the air comes at the point
of the plug portion 13a, portion of it is forced to reverse directions, which requires a
change in diameter to the flow route of the air. The original vortex must decrease in
15 diameter, and in order to do so, it must give off energy. This energy is shed in the
form of heat. The reversed portion of the air is directed out of the vortex tube 5 with
a drastically reduced temperature via the second opening at the second end 5b, also
referred to as “the cold end”. Another portion of the air escapes through the first
opening 7 in the first end 5a, also referred to as “ the hot end” of the vortex tube 5,
20 resulting in a hot airflow at the first end 5a, and a hot airflow at the second end 5b of
the vortex tube 5.
[0069] For facilitating said swirl in the vortex generating chamber 6a, a hub 12 is
inserted in the vortex generating chamber 6a around which air arriving through the
air inlet 9 is arranged to swirl in the vortex generating chamber 6a.
25 [0070] The hub 12 comprises a central opening 12a, in particular concentric with
the vortex generating chamber 6a and the first and second flow passage 6b;6c, for
receiving the aforementioned backflow of air, which backflow returns from the first
end 5a inside the first flow passage 6b and flows at the centre of the first flow passage
6b, and for guiding said backflow to flow into the second flow passage 6c.
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[0071] Figure 1b illustrates a sectional view A-A of the vortex tube 5 as viewed in
axial direction x. The central hub 12 comprises tangential holes 12b leading from
outside the central hub 12 to inside the central hub 12, and into the first flow passage
6b. The tangential holes 12b converge tangentially with a circular interior of the hub
5 12. Thereby, the air will continue to swirl along the inner face of the interior of the
central hub 12 and around the backflow moving towards the second end 5b thereby
allowing it to flow through the vortex and into the opening 12a.
[0072] In the preferred embodiment of Figure 1, the hub 12 comprises a passage
forming a part of the second flow passage 6c. In the preferred embodiment of Figure
10 1, an air guide, more specifically two air guides 10,10’, disposed in the second flow
passage 6c are disposed particularly in the passage of the hub 12 forming part of the
second flow passage 6c, wherein the hub is formed by a part inserted into the vortex
generating chamber 6a.
[0073] Generally preferably, the vortex generating chamber 6a preferably has a
15 circular or at least substantially circular cross section for facilitating said swirl.
[0074] The vortex tube 5 comprises phase change material 14 forming the inner
wall surface of the first flow passage 6c, along which inner wall surface of the first
flow passage 6b air is arranged, or at least can be arranged, to flow.
[0075] The vortex tube 5 comprises phase change material 14 forming the inner
20 wall surface of the second flow passage 6c, along which inner wall surface of the
second flow passage 6c air is arranged, or at least can be arranged, to flow.
[0076] Additionally, or alternatively the vortex tube 5 could comprises phase
change material (PCM) 14 forming the inner wall surface of the vortex generating
chamber 6a, along which inner wall surface of the vortex generating chamber 6a air
25 is arranged, or at least can be arranged, to flow

CLAIMS
1. A vortex tube (5), in particular for a ventilation system (2), comprising
a first end (5a) provided with a first outlet (7);
5 a second end (5b) provided with a second outlet (8);
a vortex generating chamber (6a) between the first end and the second
end (5a,5b);
an air inlet (9) leading from a side of the vortex tube (5) into the vortex
generating chamber (6a);
10 a first flow passage (6b) between the vortex generating chamber (6a)
and the first outlet (7);
a second flow passage (6c) between the first flow passage (6b) and the
second outlet (8);
wherein the vortex tube (5) is arranged to guide air fed into the air inlet
15 (9) to flow via the air inlet (9) into the vortex generating chamber (6a), and from
it into the first flow passage (6b), the vortex tube (5) being arranged to discharge
a portion of the air from the vortex tube (5) via the first outlet (7) at the first end
(5a), and to guide a portion of the air to flow in the first flow passage (6b) back
from the first end (5a) as backflow; the backflow being arranged to flow into the
20 second flow passage (6c) to be discharged from the vortex tube (5) via the second
outlet (8);
characterized in that the vortex tube (5) comprises one or more air
guides (10,10’) disposed inside the vortex tube (5) downstream of the vortex
generating chamber (6c) for increasing laminarity of air flow downstream of the
25 vortex generating chamber (6c), wherein one or more of said air guides (10,10’)
is an air guide (10,10’) comprising plurality of openings (11,11’), through which
openings (11,11’) air can flow.
2. A vortex tube according to claim 1, characterized in that air passing to the air
30 guide (10,10’) is arranged to split into plurality of openings (11,11’) thereof and
pass through them to the other side of the air guide (10,10’).
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3. A vortex tube according to any of the preceding claims, characterized in that
the one or more air guides (10,10’) are arranged to reduce Reynolds number of
air flow in the vortex tube (5) downstream of the vortex generating chamber (6c)
5 to be less than 2000.
4. A vortex tube according to any of the preceding claims, characterized in that
each said air guide (10,10’) is a perforated plate (10) or a grille (10’).
10 5. A vortex tube according to any of the preceding claims, characterized in that
the air guide (10,10’) comprises more than 30 of said openings (11,11’),
preferably more than 50 of said openings (11,11’).
6. A vortex tube according to any of the preceding claims, characterized in that
15 each opening (11,11’) has depth/width ratio (d/w) greater than 1.
7. A vortex tube according to any of the preceding claims, characterized in that
the openings (11,11’) extend through the air guide (10,10’) in axial direction (x)
of the flow passage (6b,6c) wherein the air guide (10,10’) in question is disposed.
20
8. A vortex tube according to any of the preceding claims, characterized in that
the vortex tube (5) comprises one or more, preferably two, of said air guides
(10,10’) disposed in the first flow passage (6b).
25 9. A vortex tube according to any of the preceding claims, characterized in that
the vortex tube (5) comprises one or more, preferably two, of said air guides
(10,10’) disposed in the second flow passage (6c).
10. A vortex tube according to any of the preceding claims, characterized
30 in that the one or more air guides (10,10’) disposed in the first flow passage (6b)
are arranged to reduce Reynolds number of air flow in the first flow passage (6b)
to be less than 2000, in particular at a point (p1), which is located between an air
guide (10,10’) and the first opening (7) and/or at a point (p2) which is located
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between an air guide (10,10’) and the vortex generating chamber (6c) said point
(p2) being at the center of the of the cross section of the first flow passage (6b)
i.e. at a point of the aforementioned backflow.
5 11. A vortex tube according to any of the preceding claims, characterized
in that air is guided to swirl in the vortex generating chamber (6a) along the inner
surface of the vortex generating chamber (6a).
12. A vortex tube according to any of the preceding claims, characterized
10 in that a hub (12) is inserted in the vortex generating chamber (6a), in particular
around which air arriving through the air inlet (9) is arranged to swirl in the
vortex generating chamber (6a).
13. A vortex tube according to any of the preceding claims, characterized
15 in that it comprises an air valve (13) for controlling discharge of air from the first
flow passage (6b) through the first outlet (7), in particular at the first end (5a).
14. A vortex tube according to any of the preceding claims, characterized
in that the air valve comprises a central plug portion for blocking flow of air at
20 the center of the cross section of the first flow passage (6b) through the valve, one
or more peripheral air passages being formed beside the central plug portion,
whereby the air valve is arranged to guide a portion of air through the one or
more peripheral air passages for being discharged from the vortex tube (5) via
the first outlet (7), and a portion of the air to flow at the center of the of the cross
25 section of the first flow passage (6b) back from the first end (5a) as backflow.
15. A vortex tube according to any of the preceding claims, characterized
in that the hub (12) comprises a central opening (12a), in particular concentric
with the vortex generating chamber (6a) and the first and second flow passage
30 (6b;6c), for receiving the backflow of air, which backflow returns from the first
end (5a) inside the first flow passage (6b) and flows at the center of the first flow
passage (6b), and for guiding said backflow to flow into the second flow passage
(6c).
2192188IN
23
16. A vortex tube according to any of the preceding claims, characterized in
that the vortex tube (5) comprises phase change material(14) forming one or more
of the following:
5 at least a portion of the inner wall surface of the vortex generating
chamber (6a), along which inner wall surface of the vortex generating chamber
(6a) air is/can be arranged to flow,
at least a portion of the inner wall surface of the first flow passage (6c),
along which inner wall surface of the first flow passage (6b) air is/can be arranged
10 to flow;
at least portion of the inner wall surface of the second flow passage (6c),
along which inner wall surface of the second flow passage (6c) air is/can be
arranged to flow.
15 17. A ventilation system (2) arranged to ventilate an interior (1,1’,1’’) comprising
an air supply duct (3); and
a device (4) for feeding air into the air supply duct (3); and
a vortex tube (5) according to any of the preceding claims;
a first outlet duct (71) connected to the first outlet opening (7) and the
20 interior (1,1’,1’’) for guiding air from the first outlet opening (7) to the interior
(1,1’,1’’) and/or a second outlet duct (81) connected to the second outlet opening
(8) and the interior (1,1’,1’’) for guiding air from the second outlet opening (8) to
the interior (1,1’,1’’).
25 18. An elevator comprising an interior (1,1’,1’’) and a ventilation system (2)
according to any of the preceding claims arranged to ventilate said interior
(1,1’,1’’).