U.S. patent application number 14/905684 was filed with the patent office on 2016-06-02 for cooling and exhaust system for a cooking oven.
The applicant listed for this patent is Electrolux Appliances Aktiebolag. Invention is credited to Sorin Tcaciuc.
Application Number | 20160153666 14/905684 |
Document ID | / |
Family ID | 49209222 |
Filed Date | 2016-06-02 |
United States Patent
Application |
20160153666 |
Kind Code |
A1 |
Tcaciuc; Sorin |
June 2, 2016 |
COOLING AND EXHAUST SYSTEM FOR A COOKING OVEN
Abstract
The present invention relates to a cooling and exhaust system
(10), in particular for a cooking oven, comprising a fan shroud
(12) and a discharging channel (14). An impeller (16) is arranged
inside the fan shroud (12), so that the fan shroud (12) and the
impeller (16) form a cross-flow fan. The discharging channel (14)
is attached at the fan shroud (12) and arranged at the
circumferential side of the impeller (16). The discharging channel
(14) includes an open end arranged opposite to the fan shroud (12).
The discharging channel (14) extends along a horizontal direction.
A first inlet (20) is arranged in an upper portion of the fan
shroud (12), while a second inlet (22) is arranged in a lower
portion of the fan shroud (12). The first inlet (20) and the second
inlet (22) are arranged at or close to opposite circumferential
sides of the impeller (16). An outlet (24) is arranged at the open
end of the discharging channel (14). Further, the present invention
relates to a cooking oven with a cooling and exhaust system
(10).
Inventors: |
Tcaciuc; Sorin; (Satu Mare,
RO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Electrolux Appliances Aktiebolag |
Stockholm |
|
SE |
|
|
Family ID: |
49209222 |
Appl. No.: |
14/905684 |
Filed: |
September 2, 2014 |
PCT Filed: |
September 2, 2014 |
PCT NO: |
PCT/EP2014/068544 |
371 Date: |
January 15, 2016 |
Current U.S.
Class: |
126/299D |
Current CPC
Class: |
F24C 15/2007 20130101;
F24C 15/2042 20130101; F24C 15/006 20130101 |
International
Class: |
F24C 15/20 20060101
F24C015/20; F24C 15/00 20060101 F24C015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 10, 2013 |
EP |
13183703.1 |
Claims
1. A cooling and exhaust system, in particular for a cooking oven,
comprising a fan shroud and a discharging channel, wherein an
impeller is arranged inside the fan shroud, so that the fan shroud
and the impeller form a cross-flow fan, the discharging channel is
attached at the fan shroud and arranged at the circumferential side
of the impeller, the discharging channel includes an open end
arranged opposite to the fan shroud, the discharging channel
extends along a horizontal direction, a first inlet is arranged in
an upper portion of the fan shroud, a second inlet is arranged in a
lower portion of the fan shroud, the first inlet and the second
inlet are arranged at or close to opposite circumferential sides of
the impeller, and an outlet is arranged at the open end of the
discharging channel.
2. The cooling and exhaust system according to claim 1,
characterized in that the first inlet is arranged above the
discharging channel.
3. The cooling and exhaust system according to claim 1,
characterized in that the direction of an air stream through the
first inlet is opposite to the direction of the air stream inside
the discharging channel.
4. The cooling and exhaust system according to claim 1,
characterized in that the direction of an air stream through the
second inlet is the same as the direction of the air stream inside
the discharging channel.
5. The cooling and exhaust system according to claim 1,
characterized in that a bottom side of the fan shroud is at least
partially open, wherein a portion of said bottom side is closed or
closable by a base plate, and wherein the base plate is a part of
the cooling and exhaust system or of the cooking oven.
6. The cooling and exhaust system according to claim 5,
characterized in that the position of the base plate is variable,
so that an air stream through the cooling and exhaust system
follows a path defined by the geometry of the cooling and exhaust
system in a predetermined manner.
7. The cooling and exhaust system according to claim 1,
characterized in that the flow of the air stream through the first
inlet is bigger than the flow of the air stream through the second
inlet.
8. The cooling and exhaust system according to claim 1,
characterized in that an exhaust pipe is arranged in the bottom of
the discharging channel so that the discharging channel is
connected or connectable to an oven cavity of the cooking oven.
9. The cooling and exhaust system according to claim 1,
characterized in that the impeller is driven by an electric motor
energized by alternating or direct current.
10. The cooling and exhaust system according to claim 1,
characterized in that the sum of the air streams through the first
inlet and the second inlet is equal to the air stream through the
outlet.
11. A cooking oven with a cooling and exhaust system, characterized
in that the cooking oven comprises the cooling and exhaust system
according to claim 1.
12. The cooking oven according to claim 11, characterized in that
the first inlet is provided for sucking air from an upper front
portion of the cooking oven.
13. The cooking oven according to claim 12, characterized in that
the first inlet is provided for sucking air from a space around a
control panel of the cooking oven.
14. The cooking oven according to claim 11, characterized in that
the second inlet is provided for sucking air from the rear side of
an oven cavity of the cooking oven.
15. The cooking oven according to claim 11, characterized in that a
bottom side of the fan shroud is at least partially open, wherein a
portion of said bottom side is closed or closable by a base plate,
wherein the base plate is arranged above an oven cavity of the
cooking oven.
Description
[0001] The present invention relates to a cooling and exhaust
system, in particular for a cooking oven. Further, the present
invention relates to a cooking oven with a cooling and exhaust
system.
[0002] Cooling and exhaust systems according to the prior art
usually operate with either an axial fan or cross-flow fan. The
cooling and exhaust systems with the axial fan provide good results
in the high efficiency of a fan shroud. Said fan shroud is able to
generate high pressure and an air flow throughout the cooling and
exhaust system. However, the axial fan is expensive and results in
high costs of the whole cooling and exhaust system. The cooling and
exhaust systems with the cross-flow fan causes only low costs and a
good efficiency. The cooling and exhaust system with the cross-flow
fan is installed above an oven cavity of the cooking oven and
directly on a driving plate. A discharging channel of the cooling
and exhaust system extends from the rear portion to a front portion
of the cooking oven. Vapour and/or hot air are eliminated through
the lower part of a control panel of the cooking oven, but
sometimes through the upper part of said control panel.
[0003] FIG. 6 illustrates a schematic sectional side view of the
cooling and exhaust system 40 and a corresponding
pressure-space-diagram according to the prior art. The upper
picture represents the cooling and exhaust system 40, while the
pressure-space-diagram is shown by the lower picture. The cooling
and exhaust system 40 comprises a fan shroud 12 and a discharging
channel 14. An impeller 16 with a plurality of fan blades 18 is
arranged inside the fan shroud 12. The rotation axis of the
impeller 16 extends perpendicular to the plane of the drawing, and
the impeller 16 rotates counterclockwise. The fan shroud 12 and the
impeller 16 form a cross-flow fan. An inlet 42 is arranged above
the impeller 16. The impeller 16 is driven by an electric motor.
The impeller 16 rotates in the direction of the action of the
forwardly inclined fan blades 18 and generates a strong suction of
an air stream from the inlet 42. The air stream follows via a path
through the fan shroud 12 and the discharging channel 14 to an
outlet 24.
[0004] An exhaust pipe 32 is installed in the bottom of the
discharging channel 14 and communicates with the ceiling of the
oven cavity. By the operation of the cross-flow fan an air suction
and a low pressure zone occurs in the exhaust pipe 32, which
extracts the vapours from the oven cavity due to the air stream in
the discharging channel 14. The vapours follow the same path as the
air stream from the inlet 42 to the outlet 24. The cooling and
exhaust system is provided for cooling the components above the
oven cavity on the one hand and eliminating the vapours released
from the cavity.
[0005] The pressure-space-diagram in the lower picture of FIG. 6
shows the distribution of the static pressure along the cooling and
exhaust system 40. The static pressure may have positive and
negative values. The distribution of the static pressure depends on
the geometry of the fan shroud 12 and on the inner shapes of the
cooling and exhaust system 40. Experimental results have shown that
the suction pressure remains low around the zone of the exhaust
pipe 32 during the operation of the cross-flow fan, since the
airflow incident angle relative to the horizontal base plate 30 has
a low value. The low static pressure in the zone of the exhaust
pipe 32 is disadvantageous, since a consistent mass of vapour
remains inside the oven cavity. Further, the low static pressure in
the zone of the exhaust pipe 32 is disadvantageous for the energy
consumption.
[0006] It is an object of the present invention to provide an
improved cooling and exhaust system, which allows low energy
consumption by low complexity and costs.
[0007] The object of the present invention is achieved by the
cooling and exhaust system according to claim 1.
[0008] The cooling and exhaust system according to the present
invention comprises a fan shroud and a discharging channel, wherein
[0009] an impeller is arranged inside the fan shroud, so that the
fan shroud and the impeller form a cross-flow fan, [0010] the
discharging channel is attached at the fan shroud and arranged at
the circumferential side of the impeller, [0011] the discharging
channel includes an open end arranged opposite to the fan shroud,
[0012] the discharging channel extends along a horizontal
direction, [0013] a first inlet is arranged in an upper portion of
the fan shroud, [0014] a second inlet is arranged in a lower
portion of the fan shroud, [0015] the first inlet and the second
inlet are arranged at or close to opposite circumferential sides of
the impeller, and [0016] an outlet is arranged at the open end of
the discharging channel.
[0017] The main idea of the present invention is the cooling and
exhaust system with two inlets and one outlet, wherein the both
inlets are arranged at opposite sides of the fan shroud. The inlets
suck air from different directions. The air is exhausted by the
common outlet. The structure of two inlets and one outlet allows an
efficient operation of the cooling and exhaust system. The impeller
may be driven by reduced power.
[0018] Preferably, the first inlet is arranged above the
discharging channel. This contributes to a compact structure of the
cooling and exhaust system.
[0019] In particular, the direction of an air stream through the
first inlet is opposite to the direction of the air stream inside
the discharging channel.
[0020] In contrast, the direction of an air stream through the
second inlet may be the same as the direction of the air stream
inside the discharging channel.
[0021] In a preferred embodiment of the present invention, a bottom
side of the fan shroud is at least partially open, wherein a
portion of said bottom side is closed or closable by a base plate,
and wherein the base plate is either a part of the cooling and
exhaust system or of the cooking oven.
[0022] Further, the position of the base plate may be variable.
Thus, an air stream through the cooling and exhaust system follows
a path defined by the geometry of the cooling and exhaust system in
a predetermined manner.
[0023] In particular, the flow of the air stream through the first
inlet is bigger than the flow of the air stream through the second
inlet. A main air stream is sucked through the first inlet, while
the second inlet sucks an additional air stream.
[0024] Moreover, an exhaust pipe may be arranged in the bottom of
the discharging channel, so that the discharging channel is
connected or connectable to an oven cavity of the cooking oven. The
structure of the two inlets, the one outlet and the exhaust pipe
allows a high negative static pressure in the discharging channel,
so that vapours can be removed from the oven cavity of the cooking
oven and exhausted through the discharging channel.
[0025] For example, the impeller is driven by an electric motor
energized by alternating or direct current.
[0026] In particular, the sum of the air streams through the first
inlet and the second inlet is equal to the air stream through the
outlet. There are no further inlets and outlets.
[0027] Furthermore, the present invention relates to a cooking oven
with the cooling and exhaust system mentioned above.
[0028] Preferably, the first inlet is provided for sucking air from
an upper front portion of the cooking oven.
[0029] In particular, the first inlet is provided for sucking air
from a space around a control panel of the cooking oven.
[0030] In contrast, the second inlet is provided for sucking air
from the rear side of an oven cavity of the cooking oven.
[0031] At last, the base plate may be arranged above the oven
cavity of the cooking oven.
[0032] Novel and inventive features of the present invention are
set forth in the appended claims.
[0033] The present invention will be described in further detail
with reference to the accompanied drawings, in which
[0034] FIG. 1 illustrates a schematic sectional side view of a
cooling and exhaust system and a corresponding
pressure-space-diagram according to a preferred embodiment of the
present invention,
[0035] FIG. 2 illustrates a schematic perspective view of the
cooling and exhaust system according to the preferred embodiment of
the present invention,
[0036] FIG. 3 illustrates a schematic perspective view of the
cooling and exhaust system according to the preferred embodiment of
the present invention,
[0037] FIG. 4 illustrates a schematic side view of the cooling and
exhaust system according to the preferred embodiment of the present
invention,
[0038] FIG. 5 illustrates a schematic sectional side view of the
cooling and exhaust system according to the preferred embodiment of
the present invention and a further schematic sectional side view
of a cooling and exhaust system according to the prior art, and
[0039] FIG. 6 illustrates a schematic sectional side view of the
cooling and exhaust system and the corresponding
pressure-space-diagram according to the prior art.
[0040] FIG. 1 illustrates a schematic sectional side view of a
cooling and exhaust system 10 and a corresponding
pressure-space-diagram according to a preferred embodiment of the
present invention. In particular, the cooling and exhaust system 10
is provided for a cooking oven. The upper picture in FIG. 1 shows
the physical cooling and exhaust system 10, while the
pressure-space-diagram is shown by the lower picture in FIG. 1.
[0041] The cooling and exhaust system 10 comprises a fan shroud 12
and a discharging channel 14. The discharging channel 14 is
attached at the fan shroud 12. The discharging channel 14 includes
an open end opposite to the fan shroud 12. The discharging channel
14 extends along a horizontal direction. An impeller 16 is arranged
inside the fan shroud 12. The impeller 16 includes a plurality of
fan blades 18. The rotation axis of the impeller 16 extends
perpendicular to the plane of the drawing in FIG. 1. The impeller
16 rotates counterclockwise in FIG. 1. The fan blades 18 are
inclined in forward direction. The fan shroud 12 and the impeller
16 form a cross-flow fan. The impeller 16 is driven by an electric
motor 26, which is not shown in FIG. 1. The impeller 16 generates a
tangential air stream inside the fan shroud 12. Said air stream is
set forth inside the discharging channel 14 as a substantially
straightforward air stream 36. The cooling and exhaust system 10
includes a base plate 30 at its bottom. A lower part of the fan
shroud 12 is formed by a portion of said base plate 30.
[0042] The cooling and exhaust system 10 includes a first inlet 20,
a second inlet 22 and an outlet 24. The first inlet 20 is arranged
above the junction of the fan shroud 12 and discharging channel 14.
The second inlet 22 is arranged at the bottom of the fan shroud 12
and at the circumferential side of the impeller 16. The outlet 24
is arranged at the open end of the discharging channel 14. The
first inlet 20 and the second inlet 22 are arranged at opposed
circumferential sides of the impeller 16. The direction of the air
flow at the first inlet 20 is substantially reversed relating to
the direction of the air flow at the outlet 24. In contrast, the
direction of the air flow at the second inlet 22 is substantially
the same as the direction of the air flow at the outlet 24.
[0043] A bigger part of the sucked air stream passes the first
inlet 20, while a smaller part of the sucked air stream passes the
second inlet 22. A large mass of fresh air is sucked by the
impeller 16 through the first inlet 12 and creates a main air
stream inside the cooling and exhaust system 10. For example, said
fresh air is sucked from the space around the control panel of the
cooking oven, wherein the air around the control panel is replaced
by another fresh air pulled into the oven casing from the external
environment of the cooking oven. The control panel and its
components may be cooled down by the air from the external
environment.
[0044] The smaller part of the air stream sucked by the impeller 16
passes the second inlet 22. For example, the air stream sucked
through the second inlet 22 is captured from the rear side of an
oven cavity of the cooking oven. The air at the rear side of the
oven cavity is replaced by fresh air pulled in form the external
environment above the cooking oven. The air at the rear side of the
oven cavity is generated by heating elements of the cooking oven
and accumulated at said rear side of the oven cavity. The second
inlet 22 compensates the difference between the air flows of the
outlet 24 and the first inlet 20. Thus, the mass of the air stream
circulating in the cooling and exhaust system 10 has permanently a
constant value.
[0045] The sum of both air streams from the first inlet 20 and
second inlet 22 form an air stream 36 inside the discharging
channel 14. The air stream 36 exhausts through the outlet 24 at the
open end of the discharging channel 14. The air stream from the
second inlet 22 deflects the sum of both air streams from the first
inlet 20 and second inlet 22, so that the direction of said sum of
both air streams has an airflow incident angle 38 with a high value
relating to the base plate 30. This is a result of Bernoulli law,
in which the sum of the potential energy, kinetic energy and
pressure remains constant along a closed aerodynamic channel. The
air stream from the second inlet 22 contributes to disturbances, a
relative low kinetic energy and a relative high negative pressure
at the entry of the discharging channel 14.
[0046] An exhaust pipe 32 is arranged in the bottom of the
discharging channel 14. The exhaust pipe 32 is connected or
connectable with a ceiling of the oven cavity. The air stream from
the second inlet 22 causes the relative high negative pressure
above the exhaust pipe 32. This results in a relative high suction
force of the air stream 34 through the exhaust pipe 32. Said high
suction force causes of a relative big amount of extracted vapours
from the oven cavity. The vapours follow the same path as the air
stream 36 inside the discharging channel 14. The cooling and
exhaust system 10 is provided for cooling components above the oven
cavity on the one hand and eliminating vapours released from the
oven cavity.
[0047] The pressure-space-diagram in the lower picture of FIG. 1
shows the distribution of the static pressure along the cooling and
exhaust system 10. The static pressure may have positive and
negative values characterized by the plus sign and minus sign,
respectively. The distribution of the static pressure depends on
the geometry of the fan shroud 12 and on the inner shapes of the
cooling and exhaust system 10. The suction pressure around the zone
of the exhaust pipe 32 is relative high during the operation of the
cross-flow fan, since the airflow incident angle 38 relative to the
horizontal base plate 30 has a high value. The high static pressure
in the zone of the exhaust pipe 32 is an advantage of the present
invention, since a lot of vapour is removed from the oven cavity.
Further, the high static pressure in the zone of the exhaust pipe
32 is advantageous for the energy consumption.
[0048] FIG. 2 illustrates a schematic perspective view of the
cooling and exhaust system 10 according to the preferred embodiment
of the present invention. FIG. 2 clarifies the geometric structure
of the cooling and exhaust system 10. In the perspective view of
FIG. 2 the discharging channel 14 is shown in front of the fan
shroud 12.
[0049] The cooling and exhaust system 10 comprises the fan shroud
12 and the discharging channel 14 attached at said fan shroud 12.
The outlet 24 is arranged at the open end of the discharging
channel 14. The impeller 16 is arranged inside the fan shroud 12.
The fan blades 18 of the impeller 16 are partially visible through
the first inlet 20. The electric motor 26 is arranged beside the
fan shroud 12.
[0050] The electric motor 26 is energized at different voltages.
For example, the electric motor 26 is energized by an alternating
current at voltages from 110 V to 240 V. Further, the electric
motor 26 may be also energized by direct current. For example, the
electric power of these electric motors 26 may be vary between 10 W
and 45 W. The electric power of the electric motor 26 depends on
the current requests. Preferably, the electric motor 26 is of a
shaded pole type or a squirrel cage type.
[0051] FIG. 3 illustrates a schematic perspective view of the
cooling and exhaust system 10 according to the preferred embodiment
of the present invention. In the perspective view of FIG. 3 shows
that side of the fan shroud 12, at which the electric motor 26 is
attached.
[0052] FIG. 4 illustrates a schematic side view of the cooling and
exhaust system 10 according to the preferred embodiment of the
present invention.
[0053] The discharging channel 14 attached at said fan shroud 12.
The outlet 24 is arranged at the open end of the discharging
channel 14. The impeller 16 is arranged inside the fan shroud 12.
The fan blades 18 of the impeller 16 are partially visible through
the first inlet 20. The electric motor 26 is arranged beside the
fan shroud 12, but not visible in FIG. 4. The first inlet 20 and
the second inlet 22 are arranged at the opposed circumferential
sides of the fan shroud 12.
[0054] FIG. 5 illustrates a schematic sectional side view of the
cooling and exhaust system 10 according to the preferred embodiment
of the present invention and a further schematic sectional side
view of a cooling and exhaust system 40 according to the prior art.
An upper picture in FIG. 5 shoes the cooling and exhaust system 40
according to the prior art, while a lower upper picture in FIG. 5
shows the cooling and exhaust system 10 according to the present
invention. The cooling and exhaust system 10 according to the
preferred embodiment is compared with cooling and exhaust system 40
of the prior art.
[0055] The discharging channels 14 of the present invention and the
prior art have different heights 28 and 46. A height 28 of the
discharging channel 14 of the inventive cooling and exhaust system
10 is bigger than a corresponding height 46 of the discharging
channel 14 of the inventive cooling and exhaust system 40 according
to the prior art. In order to avoid unwanted vibrations generated
by induction, the electric motor 26 should be arranged at a minimum
height. Preferably, the distance between the electric motor 26 and
the bottom of the base plate 30 should be at least 10 mm. The
residual dimensions of the both cooling and exhaust systems 10 and
40 are substantially the same.
[0056] FIG. 6 illustrates a schematic sectional side view of the
cooling and exhaust system 40 and the corresponding
pressure-space-diagram according to the prior art. The upper
picture represents the cooling and exhaust system 40, while the
pressure-space-diagram is shown by the lower picture. The cooling
and exhaust system 40 comprises the fan shroud 12 and the
discharging channel 14. The impeller 16 with the plurality of fan
blades 18 is arranged inside the fan shroud 12. The rotation axis
of the impeller 16 extends perpendicular to the plane of the
drawing. The impeller 16 rotates counterclockwise. The fan shroud
12 and the impeller 16 form the cross-flow fan. An inlet 42 is
arranged above the impeller 16. The impeller 16 is driven by the
electric motor. The impeller 16 rotates in the direction of the
action of the forwardly inclined fan blades 18 and generates the
strong suction of an air stream from the inlet 42. The air stream
follows via the path through the fan shroud 12 and the discharging
channel 14 to the outlet 24.
[0057] The exhaust pipe 32 is installed in the bottom of the
discharging channel 14 and communicates with the ceiling of the
oven cavity. By the operation of the cross-flow fan the air suction
and low pressure zone occurs in the exhaust pipe 32, which extracts
the vapours from the oven cavity due to the air stream in the
discharging channel 14. The vapours follow the same path as the air
stream from the inlet 42 to the outlet 24. Also the cooling and
exhaust system 40 is provided for cooling the components above the
oven cavity on the one hand and eliminating the vapours released
from the cavity.
[0058] The pressure-space-diagram in the lower picture of FIG. 6
shows the distribution of the static pressure along the cooling and
exhaust system 40. The static pressure has positive and negative
values. The distribution of the static pressure depends on the
geometry of the fan shroud 12 and on the inner shapes of the
cooling and exhaust system 40. The suction pressure remains low
around the zone of the exhaust pipe 32 during the operation of the
cross-flow fan, since the airflow incident angle 44 relative to the
horizontal base plate 30 has a low value. The low static pressure
in the zone of the exhaust pipe 32 is disadvantageous, since a
consistent mass of vapour remains inside the oven cavity. Further,
the low static pressure in the zone of the exhaust pipe 32 is
disadvantageous for the energy consumption.
[0059] Although an illustrative embodiment of the present invention
has been described herein with reference to the accompanying
drawings, it is to be understood that the present invention is not
limited to that precise embodiment, and that various other changes
and modifications may be affected therein by one skilled in the art
without departing from the scope or spirit of the invention. All
such changes and modifications are intended to be included within
the scope of the invention as defined by the appended claims.
LIST OF REFERENCE NUMERALS
[0060] 10 cooling and exhaust system [0061] 12 fan shroud [0062] 14
discharging channel [0063] 16 impeller [0064] 18 fan blade [0065]
20 first inlet [0066] 22 second inlet [0067] 24 outlet [0068] 26
electric motor [0069] 28 height of the discharging channel 14
[0070] 30 base plate [0071] 32 exhaust pipe [0072] 34 air stream
through the exhaust pipe 32 [0073] 36 air stream inside the
discharging channel 14 [0074] 38 airflow incident angle inside the
discharging channel 14 [0075] 40 cooling and exhaust system of the
prior art [0076] 42 inlet [0077] 44 airflow incident angle inside
the discharging channel 14 [0078] 46 height of the discharging
channel 14 [0079] P pressure [0080] l length
* * * * *