[0001] The present invention relates to a convection heating device for an oven cavity of
a cooking oven. Further, the present invention relates to a fan cover for a convection
heating device in an oven cavity of a cooking oven. Moreover, the present invention
relates to a cooking oven with a convection heating device.
[0002] In the convection heating mode, forced convection plays a significant part in the
cooking process. A radial fan driven by a motor rotates and generates an air flow
taken from the oven cavity through an inlet of a fan cover arranged in front of the
rear wall of the oven cavity. Said fan cover is a separating wall between a convection
heating device and the proper oven cavity. Thus, the convection heating device forms
the rear portion of the oven cavity. Usually, the radial fan is arranged at the centre
of the rear wall of the oven cavity. Then, the air flow is heated up by a heating
element arranged between the fan cover and the rear wall of the oven cavity. At last,
the air flow enters the proper oven cavity again through opening in an outer portion
of the fan cover or through a gap between the border of the fan cover and the rear
wall of the oven cavity. The structure of the fan cover determines the geometric distribution
of the air flow into the proper oven cavity.
[0003] FIG 5 illustrates a schematic front view of the convection heating device in the
oven cavity of the cooking oven according to the prior art. Said convection heating
device is arranged in a rear portion of the oven cavity 10 and directly in front of
the rear wall 12 of said oven cavity 10. The convection heating device comprises the
fan cover 14, the radial fan 16 and the heating element 18. The fan cover 14 is substantially
formed as a sheet and arranged parallel to the rear wall 12 of the oven cavity 10.
The radial fan 16 is arranged between the fan cover 14 and the rear wall 12. Further,
the radial fan 16 is arranged in the central portion of the rear wall 12. The rotation
axis of the radial fan 16 extends perpendicular to the planes of the fan cover 14
and the rear wall 12. The heating element 18 encloses the radial fan 16. The fan cover
14 comprises the inlet section 20 and the outlet section 22. The inlet section 20
is arranged in the central portion of the fan cover 14 and in front of the radial
fan 16. The outlet section 22 is formed between the border of the fan cover 16 and
the rear wall 12 of the oven cavity 10.
[0004] The radial fan 16 sucks the airflow 26 from the centre of the oven cavity 10 through
the inlet section 20. The airflow 26 to the radial fan 16 streams parallel to the
rotation axis of the radial fan 16. From the radial fan 16 the airflow 26 streams
radially to the rotation axis of the radial fan 16 and then through the outlet section
22 into the oven cavity 10.
[0005] FIG 6 illustrates a schematic top view of the convection heating device in the oven
cavity 10 of the cooking oven according to the prior art. The radial fan 16 sucks
the airflow 26 from the centre of the oven cavity 10 through the inlet section 20,
wherein said airflow 26 streams parallel to the rotation axis of the radial fan 16.
Afterwards the air flow 26 from the radial fan 16 radially to the rotation axis of
the radial fan 16 and between the fan cover 14 and the rear wall 12 of the oven cavity
10 and then through the outlet section 22 into the oven cavity 10. Thereby a substantial
part of the air flow 26 streams along the side walls of the oven cavity 10 and towards
to an oven door and is then redirected to the central portion of the oven cavity 10.
The fan cover 14 avoids that the air flow 26 is directly blown from the heating element
to the food stuff in the centre of the oven cavity 10.
[0006] However, the side walls of the oven cavity 10 are heated up strongly, since a substantial
part of the air flow 26 streams along said side walls. The side walls form a large
thermal mass, so that the energy losses to the ambient increase and therefore energy
consumption increases. It would be advantageous, if the heating-up of the side walls
of the oven cavity 10 could be reduced.
[0007] It is an object of the present invention to provide a convection heating device for
an oven cavity of a cooking oven, wherein said fan cover avoids a strong heating-up
of the said walls of the oven cavity.
[0008] The object is achieved by the convection heating device according to claim 1.
[0009] According to the present invention a convection heating device for an oven cavity
of a cooking oven is provided, wherein said convection heating device is arrangeable
or arranged at a rear wall of the oven cavity, and wherein:
- the convection heating device comprises a radial fan, at least one heating element
and a fan cover,
- the radial fan and the heating element are arrangeable or arranged between the fan
cover and the rear wall of the oven cavity,
- at least one main plane of the fan cover extends parallel to the rear wall in the
mounted state of said fan cover,
- the fan cover comprises an inlet section arranged in a central portion of said fan
cover,
- the inlet section includes a plurality of holes and/or slots,
- the fan cover comprises an outlet section arranged in an outer portion of said fan
cover,
- the outlet section includes a number of cut-outs,
- the inlet section and outlet section are arranged in the main plane of the fan cover,
- the fan cover comprises a side wall enclosing a border of said fan cover and extending
rearwards from the main plane of said fan cover,
- the cut-outs of the outlet section have longitudinal shapes,
- the longitudinal axes of the cut-outs of the outlet section are inclined with respect
to corresponding reference axes perpendicular to radial directions originating from
the centre of the fan cover, so that the longitudinal axes of the cut-outs are arranged
perpendicular to the directions of air flows arriving at said cut-outs, and
- at least one cut-out of the outlet section comprises a deflecting plate extending
rearwards from that longitudinal side of said cut-out, which is the closest longitudinal
side to the centre of the fan cover.
[0010] The core of the present invention is the orientation of the cut-outs of the outlet
section with respect to the directions of air flows from the radial fan on the one
hand and the deflecting plate extending rearwards on the other hand. The air flows
from the radial fan have radial components, but also tangential components. The orientation
of the cut-out of the outlet section allows that a maximum part of the air flow reaches
perpendicularly the longitudinal side of said cut-out. The deflecting plate extending
rearwards is preferably placed upstream respect to the incoming flow, and generates
favoured turbulences, preferably which guide the air flow into said cut out so air
flow emerge perpendicular to the fan cover. The airflow from the convection heating
device into the oven cavity removes away from the side walls of the oven cavity on
the one hand and passes by the food stuff arranged in the centre of said oven cavity
on the other hand. The heating-up of the side walls of the oven cavity is reduced
and the heat distribution inside the oven cavity is substantially even. The inventive
convection heating device avoids energy losses in the environment of the side walls
of the oven cavity.
[0011] For example, the angles between the longitudinal axes of the cut-outs of the outlet
section and the corresponding reference axes are between 30° and 60°, in particular
between 40° and 50°. The angles are adapted to the direction of the airflow from the
radial fan. Said airflow from the radial fan has a radial and a tangential component.
[0012] Preferably, the deflecting plate has the same size as the corresponding cut-out.
[0013] In particular, the deflecting plate extends perpendicular to the main plane of the
fan cover.
[0014] According to one embodiment of the present invention, at least one longitudinal side
of the cut-outs of the outlet section is linear.
[0015] In this case, at least one deflecting plate may be plane.
[0016] According to another embodiment of the present invention, at least one longitudinal
side of the cut-outs of the outlet section is curved.
[0017] Further, the at least one curved longitudinal side of the cut-out of the outlet section
may be concave to the centre of the fan cover.
[0018] In the latter case, also at least one deflecting plate may be curved.
[0019] In particular, the curved deflecting plate has the same curvature as the corresponding
curved longitudinal side of the cut-out.
[0020] Moreover, the size of the inlet section of the fan cover may be adapted to the size
of the radial fan. This optimizes the air flow from the oven cavity into the convection
heating device.
[0021] Further, the present invention relates to a fan cover for a convection heating device
in an oven cavity of a cooking oven, wherein:
- the fan cover is arrangeable or arranged in front of a radial fan attached at a rear
wall of the oven cavity,
- at least one main plane of the fan cover extends parallel to the rear wall in the
mounted state of said fan cover,
- the fan cover comprises an inlet section arranged in a central portion of said fan
cover,
- the inlet section includes a plurality of holes and/or slots,
- the fan cover comprises an outlet section arranged in an outer portion of said fan
cover,
- the outlet section includes a number of cut-outs,
- the inlet section and outlet section are arranged in the main plane of the fan cover,
- the fan cover comprises a side wall enclosing a border of said fan cover and extending
rearwards from the main plane of said fan cover,
- the cut-outs of the outlet section have longitudinal shapes,
- the longitudinal axes of the cut-outs of the outlet section are inclined with respect
to corresponding reference axes perpendicular to radial directions originating from
the centre of the fan cover, so that the longitudinal axes of the cut-outs are arranged
perpendicular to the directions of airflows arriving at said cut-outs, and
- at least one cut-out of the outlet section comprises a deflecting plate extending
rearwards from that longitudinal side of said cut-out, which is the closest longitudinal
side to the centre of the fan cover.
[0022] In particular, the fan cover is provided for the convection heating device mentioned
above.
[0023] Preferably, the at least one heating element encloses the radial fan.
[0024] For example, the at least one heating element is a ring heating element.
[0025] Moreover, the present invention relates to a cooking oven with a convection heating
device, wherein the cooking oven comprises a convection heating device and/or a fan
cover mentioned above.
[0026] In particular, the width and/or the height of the fan cover are marginally smaller
than the width and the height, respectively, of the rear wall of the oven cavity.
[0027] Preferably, a space between the fan cover, the side wall of said fan cover and the
rear wall of the oven cavity is closed, without regard to the inlet section and outlet
section.
[0028] Novel and inventive features of the present invention are set forth in the appended
claims.
[0029] The present invention will be described in further detail with reference to the drawing,
in which
- FIG 1
- illustrates a schematic front view and top view of a convection heating device in
an oven cavity of a cooking oven according to a first embodiment of the present invention,
- FIG 2
- illustrates a schematic front view and top view of the convection heating device in
the oven cavity of the cooking oven according to a second embodiment of the present
invention,
- FIG 3
- illustrates a schematic top view of the convection heating device in the oven cavity
of the cooking oven according to the first and second embodiment of the present invention,
- FIG 4
- illustrates a detailed schematic top view of the convection heating device in the
oven cavity of the cooking oven according to the first and second embodiment of the
present invention,
- FIG 5
- illustrates a schematic front view of the convection heating device in the oven cavity
of the cooking oven according to the prior art, and
- FIG 6
- illustrates a schematic top view of the convection heating device in the oven cavity
of the cooking oven according to the prior art.
[0030] FIG 1 illustrates a schematic front view and top view of a convection heating device
in an oven cavity 10 of a cooking oven according to a first embodiment of the present
invention. The front view of the convection heating device is shown in the upper picture
in FIG 1, while the top view of said convection heating device is shown in the lower
picture therein.
[0031] The convection heating device is arranged in a rear portion of the oven cavity 10
and directly in front of the rear wall 12 of said oven cavity 10. The convection heating
device comprises a fan cover 14, a radial fan 16 and a heating element 18. The fan
cover 14 is substantially formed as a sheet and arranged parallel to the rear wall
12 of the oven cavity 10. The radial fan 16 is arranged between the fan cover 14 and
the rear wall 12. The radial fan 16 is arranged in a central portion of the rear wall
12. The rotation axis of the radial fan 16 extends perpendicular to the planes of
the fan cover 14 and the rear wall 12. In this example, the heating element 18 encloses
the radial fan 16.
[0032] The fan cover 14 comprises an inlet section 20 and an outlet section 22. The inlet
section 20 is arranged in a central portion of the fan cover 14. The inlet section
20 includes a plurality of holes. Said plurality of holes is substantially arranged
in front of the radial fan 16. The outlet section 22 includes a number of cut-outs
arranged in an outer portion of the fan cover 16. In this example, the outlet section
22 of the fan cover 14 includes four cut-outs. In this embodiment, each cut-out has
a rectangular shape and hence four edges. The longitudinal sides of the rectangular
cut-outs are arranged substantially perpendicular to the direction of the airflow
from the radial fan 16.
[0033] A side wall 28 encloses the border of said fan cover 14. The side wall 28 extends
perpendicular to the fan cover 14. In this example, the fan cover 14 and the side
wall 28 are formed as a single-piece part. The side wall 28 extends rearwards from
the border of the fan cover 14 to the rear wall 12 of the oven cavity 10. The rear
wall 12, the fan cover 14 and the side wall 28 form a space. Without regard to the
inlet section 20 and outlet section 22, said space is a closed space.
[0034] Further, each cut-out includes a deflecting plate 24 at one edge. The deflecting
plate 24 is arranged at that edge, which is the closest to the radial fan 16 and to
the centre of the fan cover 14. The deflecting plates 24 are bended rearward. The
planes of the deflecting plates 24 extend substantially perpendicular to the planes
of the rear wall 12 and fan cover 14. In this example, the area of each deflecting
plate 24 is the same as the corresponding cut-out. Thus, the deflecting plate 24 may
be obtained by a U-shaped cut in the fan cover 14, wherein the resulting flap is subsequently
bended rearwards.
[0035] The deflecting plates 24 generate favoured turbulences. Said turbulence contribute
that the airflow from the convection heating device into the oven cavity, preferably
emerging perpendicularly to the fan cover 14, and therefore removes away from the
side walls of the oven cavity on the one hand and passes by the food stuff arranged
in the centre of said oven cavity on the other hand.
[0036] The radial fan 16 sucks the airflow 26 from the centre of the oven cavity 10 through
the inlet section 20. The airflow 26 to the radial fan 16 streams parallel to the
rotation axis of the radial fan 16. In contrast, the airflow 26 from the radial fan
16 streams radial to the rotation axis of the radial fan 16. However, the airflow
26 from the radial fan 16 has also a component tangential to the rotation axis of
the radial fan 16. Initially, the radial fan 16 blows the airflow 26 between the rear
wall 12 and the fan cover 14 and parallel to planes of the rear wall 12 and fan cover
14. Then, the airflow 26 from the radial fan 16 is deflected by the deflecting plates
24, streams through the cut-outs of the outlet section 22 and substantially forwards
into a central portion of the oven cavity 10.
[0037] The airflow 26 from the radial fan 16 has also a component tangential to the rotation
axis of the radial fan 16. The orientation of the rectangular cut-outs are arranged
substantially perpendicular to the direction of the airflow 26 from the radial fan
16.
[0038] FIG 2 illustrates a schematic front view and top view of the convection heating device
in the oven cavity 10 of the cooking oven according to a second embodiment of the
present invention. The front view of the convection heating device is shown in the
upper picture in FIG 2, while the top view of said convection heating device is shown
in the lower picture therein.
[0039] The convection heating device according to the second embodiment has substantially
the same structure as the convection heating device of the first embodiment. The first
and second embodiments differ in the shapes of the cut-outs of the outlet section
22. In the second embodiment the longitudinal sides of the cut-outs are curved. The
longitudinal sides of the cut-outs are concave in relation to the incident air flow
26. The directions of the incident air flow 26 are perpendicular to the corresponding
sections of the longitudinal side. The deflecting plates 24 are similarly curved as
the corresponding longitudinal sides.
[0040] The convection heating devices according to the first and second embodiments may
be combined. The fan cover 14 may include one or more cut-outs with linear longitudinal
sides as well as one or more cut-outs with curved longitudinal sides.
[0041] FIG 3 illustrates a schematic top view of the convection heating device in the oven
cavity 10 of the cooking oven according to the first and second embodiment of the
present invention. FIG 3 clarifies the distribution of the airflow 26.
[0042] The airflow 26 is sucked by the radial fan 16 from the centre of the oven cavity
10 through the inlet section 20, wherein the airflow 26 to the radial fan 16 streams
substantially parallel to the rotation axis of the radial fan 16. Then, the airflow
26 leaves the radial fan 16 radial to the rotation axis of said radial fan 16, wherein
the airflow 26 is blown by the radial fan 16 between the rear wall 12 and the fan
cover 14 and parallel to planes of said rear wall 12 and fan cover 14. Afterwards,
the airflow 26 from the radial fan 16 is deflected by the deflecting plates 24, streams
through the cut-outs of the outlet section 22 and substantially forwards into the
oven cavity 10. Thereby, the distance between the airflow 26 and the side wall of
the oven cavity 10 increases. Thus, the hot airflow 26 does not directly impact onto
the side walls of the oven cavity 10. Otherwise, the hot airflow 26 does not directly
impact onto food stuff in the centre of the oven cavity 10. These properties effect
reduced heating-up of the side walls of the oven cavity 10 as well as a substantially
even heat distribution inside said oven cavity 10. The inventive fan cover 14 avoids
energy losses in the environment of the side walls of the oven cavity 10.
[0043] FIG 4 illustrates a detailed schematic top view of the convection heating device
in the oven cavity 10 of the cooking oven according to the first and second embodiment
of the present invention. FIG 4 shows the environment around a cut-out of the outlet
section 22.
[0044] Turbulences 30 are formed downstream the deflecting plate 24. Said turbulences 30
allow the deflection of the air flow 26. Without the deflecting plate 24, the air
flow 26 would stream lineally through the cut-out into the oven cavity 10 and then
towards to the side wall of said oven cavity.
[0045] FIG 5 illustrates a schematic front view of the convection heating device in the
oven cavity of the cooking oven according to the prior art.
[0046] The convection heating device of the prior art is arranged in a rear portion of the
oven cavity 10 and directly in front of the rear wall 12 of said oven cavity 10. The
convection heating device comprises the fan cover 14, the radial fan 16 and the heating
element 18. The fan cover 14 is substantially formed as a sheet and arranged parallel
to the rear wall 12 of the oven cavity 10. The radial fan 16 is arranged between the
fan cover 14 and the rear wall 12. The radial fan 16 is arranged in a central portion
of the rear wall 12. The rotation axis of the radial fan 16 extends perpendicular
to the planes of the fan cover 14 and the rear wall 12. The heating element 18 encloses
the radial fan 16.
[0047] The fan cover 14 comprises the inlet section 20 and the outlet section 22. The inlet
section 20 is arranged in a central portion of the fan cover 14 and in front of the
radial fan 16. The outlet section 22 is formed between the border of the fan cover
16 and the rear wall 12 of the oven cavity 10.
[0048] The radial fan 16 sucks the airflow 26 from the centre of the oven cavity 10 through
the inlet section 20. The airflow 26 to the radial fan 16 streams parallel to the
rotation axis of the radial fan 16. From the radial fan 16 the airflow 26 streams
radially to the rotation axis of the radial fan 16 and then through the outlet section
22 into the oven cavity 10.
[0049] FIG 6 illustrates a schematic top view of the convection heating device in the oven
cavity 10 of the cooking oven according to the prior art. The radial fan 16 sucks
the airflow 26 from the centre of the oven cavity 10 through the inlet section 20,
wherein said airflow 26 streams parallel to the rotation axis of the radial fan 16.
Afterwards the air flow 26 from the radial fan 16 radially to the rotation axis of
the radial fan 16 and between the fan cover 14 and the rear wall 12 of the oven cavity
10 and then through the outlet section 22 into the oven cavity 10. Thereby a substantial
part of the air flow 26 streams along a side wall of the oven cavity 10, so that the
side walls of the oven cavity 10 are heated up strongly. The side walls form a large
thermal mass resulting in large energy consumption.
[0050] The large energy consumption on grounds of the heating-up of the side walls of the
oven cavity 10 is overcome by the fan cover 14 according to the present invention.
Additionally, the fan cover 14 of the present invention allows a substantially even
heat distribution inside the oven cavity 10.
List of reference numerals
[0051]
- 10
- oven cavity
- 12
- rear wall
- 14
- fan cover
- 16
- radial fan
- 18
- heating element
- 20
- inlet section
- 22
- outlet section
- 24
- deflecting plate
- 26
- airflow
- 28
- side wall
- 30
- turbulences
1. A convection heating device for an oven cavity (10) of a cooking oven, wherein said
convection heating device is arrangeable or arranged at a rear wall (12) of the oven
cavity (10), and wherein:
- the convection heating device comprises a radial fan (16), at least one heating
element (18) and a fan cover (14),
- the radial fan (16) and the heating element (18) are arrangeable or arranged between
the fan cover (14) and the rear wall (12) of the oven cavity (10),
- at least one main plane of the fan cover (14) extends parallel to the rear wall
(12) in the mounted state of said fan cover (14),
- the fan cover (14) comprises an inlet section (20) arranged in a central portion
of said fan cover (14),
- the inlet section (20) includes a plurality of holes and/or slots,
- the fan cover (14) comprises an outlet section (22) arranged in an outer portion
of said fan cover (14),
- the outlet section (22) includes a number of cut-outs,
- the inlet section (20) and outlet section (22) are arranged in the main plane of
the fan cover (14),
- the fan cover (14) comprises a side wall (28) enclosing a border of said fan cover
(14) and extending rearwards from the main plane of said fan cover (14),
- the cut-outs of the outlet section (22) have longitudinal shapes,
- the longitudinal axes of the cut-outs of the outlet section (22) are inclined with
respect to corresponding reference axes perpendicular to radial directions originating
from the centre of the fan cover (14), so that the longitudinal axes of the cut-outs
are arranged perpendicular to the directions of air flows arriving at said cut-outs,
and
- at least one cut-out of the outlet section (22) comprises a deflecting plate (24)
extending rearwards from that longitudinal side of said cut-out, which is the closest
longitudinal side to the centre of the fan cover (14), in particular wherein said
deflecting plate (24) is placed upstream to the flow direction.
2. The convection heating device according to claim 1, characterised in that
the angles between the longitudinal axes of the cut-outs of the outlet section (22)
and the corresponding reference axes are between 30° and 60°, in particular between
40° and 50°.
3. The convection heating device according to claim 1 or 2, characterised in that
the deflecting plate (24) has the same size as the corresponding cut-out.
4. The convection heating device according to any one of the preceding claims,
characterised in that
the deflecting plate (24) extends perpendicular to the main plane of the fan cover
(14).
5. The convection heating device according to any one of the preceding claims,
characterised in that
at least one longitudinal side of the cut-outs of the outlet section (22) is linear,
wherein at least one deflecting plate (24) is plane.
6. The convection heating device according to any one of the preceding claims,
characterised in that
at least one longitudinal side of the cut-outs of the outlet section (22) is curved.
7. The convection heating device according to claim 6,
characterised in that
the at least one curved longitudinal side of the cut-out of the outlet section (22)
is concave to the centre the fan cover (14).
8. The convection heating device according to claim 6 or 7,
characterised in that
at least one deflecting plate (24) is curved, wherein preferably the curved deflecting
plate (24) has the same curvature as the corresponding curved longitudinal side of
the cut-out.
9. The convection heating device according to any one of the preceding claims,
characterised in that
the size of the inlet section (20) of the fan cover (14) is adapted to the size of
the radial fan (16).
10. The convection heating device according to any one of the preceding claims,
characterised in that
the at least one heating element (18) encloses the radial fan (16), wherein preferably
the at least one heating element is a ring heating element (18).
11. A fan cover (14) for a convection heating device in an oven cavity (10) of a cooking
oven, wherein:
- the fan cover (14) is arrangeable or arranged in front of a radial fan (16) attached
at a rear wall (12) of the oven cavity (10),
- at least one main plane of the fan cover (14) extends parallel to the rear wall
(12) in the mounted state of said fan cover (14),
- the fan cover (14) comprises an inlet section (20) arranged in a central portion
of said fan cover (14),
- the inlet section (20) includes a plurality of holes and/or slots,
- the fan cover (14) comprises an outlet section (22) arranged in an outer portion
of said fan cover (14),
- the outlet section (22) includes a number of cut-outs,
- the inlet section (20) and outlet section (22) are arranged in the main plane of
the fan cover (14),
- the fan cover (14) comprises a side wall (28) enclosing a border of said fan cover
(14) and extending rearwards from the main plane of said fan cover (14),
- the cut-outs of the outlet section (22) have longitudinal shapes,
- the longitudinal axes of the cut-outs of the outlet section (22) are inclined with
respect to corresponding reference axes perpendicular to radial directions originating
from the centre of the fan cover (14), so that the longitudinal axes of the cut-outs
are arranged perpendicular to the directions of airflows arriving at said cut-outs,
and
- at least one cut-out of the outlet section (22) comprises a deflecting plate (24)
extending rearwards from that longitudinal side of said cut-out, which is the closest
longitudinal side to the centre of the fan cover (14).
12. The fan cover (14) according to claim 11,
characterised in that
the fan cover (14) is provided for the convection heating device according to any
one of the claims 1 to 10.
13. A cooking oven comprising a convection heating device,
characterised in that
the cooking oven comprises a convection heating device according to any one of the
claims 1 to 10 and/or a fan cover (14) according to claim 11 or 12.
14. A cooking oven according to claim 13,
characterised in that
the width and/or the height of the fan cover (14) are marginally smaller than the
width and the height, respectively, of the rear wall (12) of the oven cavity (10).
15. A cooking oven according to claim 13 or 14,
characterised in that
a space between the fan cover (14), the side wall (28) of said fan cover (14) and
the rear wall (12) of the oven cavity (10) is closed, without regard to the inlet
section (20) and outlet section (22).