U.S. patent application number 14/111227 was filed with the patent office on 2014-01-30 for method for operating a steam oven and steam oven.
This patent application is currently assigned to ELECTROLUX HOME PRODUCTS CORPORATION N.V.. The applicant listed for this patent is Alexander Hauck, Bianca Hauslein, Laurent Jeanneteau, Marcel Morosini, Kurt Reul. Invention is credited to Alexander Hauck, Bianca Hauslein, Laurent Jeanneteau, Marcel Morosini, Kurt Reul.
Application Number | 20140027438 14/111227 |
Document ID | / |
Family ID | 44486997 |
Filed Date | 2014-01-30 |
United States Patent
Application |
20140027438 |
Kind Code |
A1 |
Hauslein; Bianca ; et
al. |
January 30, 2014 |
METHOD FOR OPERATING A STEAM OVEN AND STEAM OVEN
Abstract
The invention relates to a method for operating a steam oven
(1), especially a domestic steam oven, wherein the steam oven (1)
has a control unit (2) and a water reservoir (3) and wherein the
steam oven (1) is equipped with a pyrolytic cleaning function. To
better protect the electronics and sensors of the oven, the
invention is characterized in that the operation of the pyrolytic
cleaning comprises the following steps after the pyrolytic cleaning
function is activated by the user: a) detecting of the actual water
level (L) in the water reservoir (3) by the control unit (2); b)
comparing of the detected actual water level (L) with a defined
minimum pyrolytic water level (LMP) by the control unit (2); c)
starting the pyrolytic cleaning function by the control unit (2) if
the actual water level (L) is equal or above the minimum pyrolytic
water level (LMP) or d) not starting the pyrolytic cleaning
function but issuing of an alarm to the user by the control unit
(2) if the actual water level (L) is below the minimum pyrolytic
water level (LMP) to alert the user to fill up water into the water
reservoir (3). Furthermore, the invention relates to a steam
oven.
Inventors: |
Hauslein; Bianca;
(Rothenburg, DE) ; Reul; Kurt; (Rothenburg,
DE) ; Hauck; Alexander; (Rothenburg, DE) ;
Morosini; Marcel; (Curitiba, BR) ; Jeanneteau;
Laurent; (Forli, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hauslein; Bianca
Reul; Kurt
Hauck; Alexander
Morosini; Marcel
Jeanneteau; Laurent |
Rothenburg
Rothenburg
Rothenburg
Curitiba
Forli |
|
DE
DE
DE
BR
IT |
|
|
Assignee: |
ELECTROLUX HOME PRODUCTS
CORPORATION N.V.
Brussels
BE
|
Family ID: |
44486997 |
Appl. No.: |
14/111227 |
Filed: |
April 13, 2012 |
PCT Filed: |
April 13, 2012 |
PCT NO: |
PCT/EP12/56745 |
371 Date: |
October 11, 2013 |
Current U.S.
Class: |
219/393 ;
219/401; 219/413 |
Current CPC
Class: |
F24C 15/327 20130101;
F24C 14/02 20130101 |
Class at
Publication: |
219/393 ;
219/401; 219/413 |
International
Class: |
F24C 14/02 20060101
F24C014/02; F24C 15/32 20060101 F24C015/32 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 17, 2011 |
EP |
11003145.7 |
Claims
1. Method for operating a steam oven (1), especially a domestic
steam oven, wherein the steam oven (1) has a control unit (2) and a
water reservoir (3) and wherein the steam oven (1) is equipped with
a pyrolytic cleaning function, characterized in that the operation
of the pyrolytic cleaning comprises the following steps after the
pyrolytic cleaning function is activated by the user: a) detecting
of the actual water level (L) in the water reservoir (3) by the
control unit (2); b) comparing of the detected actual water level
(L) with a defined minimum pyrolytic water level (L.sub.MP) by the
control unit (2); c) starting the pyrolytic cleaning function by
the control unit (2) if the actual water level (L) is equal or
above the minimum pyrolytic water level (L.sub.MP) or d) not
starting the pyrolytic cleaning function but issuing of an alarm to
the user by the control unit (2) if the actual water level (L) is
below the minimum pyrolytic water level (L.sub.MP) to alert the
user to fill up water into the water reservoir (3).
2. Method according to claim 1, characterized in that the operation
of the pyrolytic cleaning furthermore comprises the steps after the
pyrolytic cleaning function is activated by the user and before
carrying out step c) of claim 1: b') after detecting of the actual
water level (L) in the water reservoir (3) according to step a) of
claim 1: comparing of the detected actual water level (L) with a
defined overfilled water level (L.sub.OF) by the control unit (2);
c') starting the pyrolytic cleaning function by the control unit
(2) if the actual water level (L) is below the overfilled water
level (L.sub.OF) or d') not starting the pyrolytic cleaning
function but issuing of an alarm to the user by the control unit
(2) if the actual water level (L) is above the overfilled water
level (L.sub.OF) to alert the user to drain water from the water
reservoir (3).
3. Method according to claim 1, characterized in that the minimum
pyrolytic water level (L.sub.MP) is a maximum water level
(L.sub.MN) for normal steam cooking operation.
4. Method according to claim 1, characterized in that the minimum
pyrolytic water level (L.sub.MP) is a water level which is between
a maximum water level (L.sub.MN) for normal steam cooking operation
and a defined overfilled water level (L.sub.OF).
5. Method according to claim 1, characterized in that an alarm is
issued to the user by the control unit (2) if the actual water
level (L) is above a defined overfilled water level (L.sub.OF) to
alert the user to drain water from the water reservoir (3).
6. Method according to claim 1, characterized in that the alarm
signal is an optical signal.
7. Method according to claim 1, characterized in that the alarm
signal is an acoustic signal.
8. Steam oven (1), especially domestic steam oven, which has a
control unit (2) and a water reservoir (3) and elements to carry
out a pyrolytic cleaning function, for carrying out the method
according to claim 1, characterized in that the steam oven (1)
comprises at least one sensor element (4) to detect the actual
water level (L) in the reservoir (3), wherein the control unit (2)
comprises means for comparing the detected actual water level (L)
with a defined minimum pyrolytic water level (L.sub.MP) and wherein
the control unit (2) comprises alarm means for issuing of an alarm
to the user if the actual water level (L) is below the minimum
pyrolytic water level (L.sub.MP) and if a pyrolytic cleaning
operation is activated.
9. Steam oven according to claim 8, characterized in that the at
least one sensor element (4) is designed to detect an overfilled
water level (L.sub.OF), wherein the control unit (2) comprises
means for comparing the detected actual water level (L) with the
overfilled water level (L.sub.OF) and wherein the control unit (2)
comprises alarm means for issuing of an alarm to the user if the
actual water level (L) is above the overfilled water level
(L.sub.OF).
10. Steam oven according to claim 8, characterized in that the
sensor element (4) comprises at least one floating magnet and relay
reeds.
11. Steam oven according to claim 8, characterized in that the
sensor element (4) is a capacitive element.
12. Steam oven according to claim 8, characterized in that the
control unit (3) is designed to calculate and output the water
volume necessary to reach a defined water level in accordance with
a detected water level by the sensor element (4).
13. Steam oven according to claim 12, characterized in that the
water level is the minimum pyrolytic water level (L.sub.MP).
14. Steam oven according to claim 12, characterized in that the
water level is the maximum water level (L.sub.MN) for normal steam
cooking operation.
15. Steam oven according to claim 8, characterized in that it
comprises optical and/or acoustic alarm signal means.
Description
[0001] The invention relates to a method for operating a steam
oven, especially a domestic steam oven, wherein the steam oven has
a control unit and a water reservoir and wherein the steam oven is
equipped with a pyrolytic cleaning function. Furthermore, the
invention relates to a steam oven.
[0002] Steam ovens of this kind are well known in the art. It is
also known that a certain amount of water is necessary in the water
reservoir for properly carrying out the steam cooking process.
Thus, water level detection in the water reservoir (water tank) is
used at least in those cases in which a water reservoir is employed
which is manually filled with water by the user. As an alternative
the steam oven can directly be connected to a water pipe.
[0003] In JP 2005273991 A a steam oven is disclosed. Here the start
of the cooking process is enabled only if enough water is present
in the water reservoir.
[0004] DE 100 38 136 A1 discloses a steam oven comprising an
emergency overflow system.
[0005] In DE 10 2008 014 040 A1 a steam oven is shown which
comprises an air bubble detection equipment in the water
supply.
[0006] It has been found that the pyrolytic process--which is often
used in steam ovens for cleaning--is a quite high thermal load to
the whole oven system. Problematic elements are especially the
electronic components and the sensor element especially for
detecting the water level in the water reservoir.
[0007] Therefore, it is an object of the invention to propose a
method for operating a steam oven of the kind mentioned above which
guarantees a better protection of the electronics and sensors of
the oven. Thus, it should be made sure that especially the
pyrolytic cleaning process does not harm the oven system.
[0008] The solution of this object is achieved by the proposed
method in that the operation of the pyrolytic cleaning comprises
the following steps after the pyrolytic cleaning function is
activated by the user: [0009] a) detecting of the actual water
level in the water reservoir by the control unit; [0010] b)
comparing of the detected actual water level with a defined minimum
pyrolytic water level by the control unit; [0011] c) starting the
pyrolytic cleaning function by the control unit if the actual water
level is equal or above the minimum pyrolytic water level or [0012]
d) not starting the pyrolytic cleaning function but issuing of an
alarm to the user by the control unit if the actual water level is
below the minimum pyrolytic water level to alert the user to fill
up water into the water reservoir.
[0013] Thus, the water level in the water reservoir is detected by
suitable sensor elements; this is managed by the control unit. Only
if a certain and special water level is given in the water
reservoir (the defined minimum pyrolytic water level) the pyrolytic
cleaning process is carried out; otherwise the user is alerted to
fill up water into the water reservoir before the pyrolytic process
is done. By doing so enough water is in the reservoir so that the
thermal load to the components is reduced due to an insulating
property of the water.
[0014] The operation of the pyrolytic cleaning can furthermore
comprises the steps after the pyrolytic cleaning function is
activated by the user and before carrying out above mentioned step
c): [0015] b') after detecting of the actual water level in the
water reservoir according to step a): comparing of the detected
actual water level with a defined overfilled water level by the
control unit; [0016] c') starting the pyrolytic cleaning function
by the control unit if the actual water level is below the
overfilled water level or [0017] d') not starting the pyrolytic
cleaning function but issuing of an alarm to the user by the
control unit if the actual water level is above the overfilled
water level to alert the user to drain water from the water
reservoir.
[0018] By doing so it is made sure that--on the other hand--not too
much water is in the water reservoir before the pyrolytic cleaning
process is carried out.
[0019] The minimum pyrolytic water level can be a maximum water
level for normal steam cooking operation.
[0020] The minimum pyrolytic water level can also be a water level
which is between a maximum water level for normal steam cooking
operation and a defined overfilled water level.
[0021] An overfilling of the water reservoir can also be detected
as such. Therefore, a version of the proposed method proposes that
an alarm is issued to the user by the control unit if the actual
water level is above a defined overfilled water level to alert the
user to drain water from the water reservoir.
[0022] When it comes to the issuance of an alarm signal this signal
can be an optical signal (e. g. a respective message on a display
of the oven) or an acoustic signal.
[0023] The proposed steam oven with the pyrolytic cleaning function
is characterized by the invention in that the steam oven comprises
at least one sensor element to detect the actual water level in the
reservoir, wherein the control unit comprises means for comparing
the detected actual water level with a defined minimum pyrolytic
water level and wherein the control unit comprises alarm means for
issuing of an alarm to the user if the actual water level is below
the minimum pyrolytic water level and if a pyrolytic cleaning
operation is activated.
[0024] The at least one sensor element can be designed to detect an
overfilled water level, wherein the control unit comprises means
for comparing the detected actual water level with the overfilled
water level and wherein the control unit comprises alarm means for
issuing of an alarm to the user if the actual water level is above
the overfilled water level.
[0025] The sensor element can comprise at least one floating magnet
and relay reeds. Also, it can be a capacitive element. Of course,
also other detection elements to measure the water level in the
water reservoir can be employed.
[0026] The control unit can be designed to calculate and output the
water volume necessary to reach a defined water level in accordance
with a detected water level by the sensor element. This means that
the invention does not only supplies the signal "too less water in
the water reservoir" or "too much water in the reservoir" but can
also inform the user how much water has to be filled or drained
into or from the tank.
[0027] Furthermore, the steam oven can comprise optical and/or
acoustic alarm signal means.
[0028] So, the invention allows to detect the exact level of water
reservoir of the steam oven which adds the functionality of
over-fill detection. Furthermore, the proposed concept tells the
user in an accurate manner how much water is missing in the water
reservoir or exactly how much water is too much in the
reservoir.
[0029] By the concept according to the invention electronic and
sensor elements which are employed to run the oven and to detect
the water level in a precise way are specifically protected against
overheating during the pyrolytic process; the pyrolytic cleaning
function of the oven is only enabled, if enough water is in the
water reservoir.
[0030] The present invention can be employed in the case that a
removable water tank is used within the steam oven. It can also be
the case that a build-in water reservoir is used which cannot be
removed. Especially if this water reservoir is not visible for the
user and thus that the water level cannot easily be monitored by
the user the present invention develops its full benefits.
[0031] A removable water tank normally reduces the available space
of the cavity or of the front panel of the oven. An invisible
reservoir is sometimes better in this respect.
[0032] So, the concept according to the invention also defines at
least two water levels, i. e. a maximum water level for normal
steam cooking and an overfilled water level. By the proposed
solution it becomes redundant to equip the system with a drain pipe
for the case the too much water is in the water reservoir. Draining
of water via a drain pipe of course has significant disadvantages
which can be avoided by the invention.
[0033] A draining pipe can be arranged which is manually activated
by the user to remove water from the reservoir.
[0034] Due to the sufficient water level in the water reservoir
during the pyrolytic cleaning process it is made sure that the
electronics and sensor element cannot be damaged due to too high
temperatures.
[0035] The sensors for detecting the water level can thus easier be
designed to detect a big range of filling degrees of the
reservoir.
[0036] Due to a visual and/or acoustical alert the user can be
easily informed concerning the filling or overfilling status of the
reservoir.
[0037] Via the display the user can also be specifically informed
how much water (i. e. how many millilitre) has to be refilled or
drained into or from the reservoir. This can be done in a quite
accurate manner due to the design of the sensor.
[0038] Consequently, the water reservoir does not need an automatic
draining pipe system for the case of overfilling.
[0039] In the case of gas cavity, where internal overfilling is not
recommended, the proposed oven avoids the leak of water in an
undesirable way.
[0040] Thus, the user of the oven is better guided to ensure the
right degree of filling of the water reservoir according to the
actual process which is running in the steam oven (normal cooking
operation or pyrolytic cleaning).
[0041] In the drawings an embodiment of the invention is
depicted.
[0042] FIG. 1 shows a schematic illustration of a steam oven in a
sectional side view and
[0043] FIG. 2 shows an enlarged view of the water reservoir of the
steam oven according to the depiction of FIG. 1.
[0044] In FIG. 1 a steam oven 1 is shown schematically which has a
cooking cavity 5 closable by a door 6. The steam oven is equipped
with a well known arrangement to supply water steam into the cavity
5. For doing so, the steam oven 1 comprises a water reservoir 3
(water tank) in which water can be filled. Thus, the water which is
filled into the water reservoir 3 reaches up to an actual water
level L.
[0045] In the water reservoir 3 a sensor element 4 is arranged
which is able to detect the actual water level L. The detected
value for the actual water level is forwarded to a control unit 2
of the steam oven 1.
[0046] As can be seen in more detail in FIG. 2 the water level L
can reach a maximum water level L.sub.MN for normal steam cooking.
I. e. this water level L.sub.MN is the maximum water level for the
water in the reservoir 3 when normal cooking operation is
required.
[0047] Furthermore, the water level can reach an overfilled water
level L.sub.OF which is a bit above the level L.sub.MN, e. g. this
level is reached when 10% to 20% more water is filled in the
reservoir as in the case of the filling degree up to the level
L.sub.MN.
[0048] Also the steam oven 1 is equipped with--not depicted--means
for carrying out a pyrolytic cleaning operation of the cavity 5.
When pyrolytic cleaning is carried out a minimum pyrolytic water
level L.sub.MP must be maintained.
[0049] In the present case the minimum pyrolytic water level
L.sub.MP is equal to the maximum water level L.sub.MN for normal
steam cooking; but this needs not to be necessarily the case.
[0050] When a pyrolytic cleaning operation has to be carried out
the user selects the respective pyrolytic cleaning program by means
of an Input-Output-Device (not shown but connected with the control
unit 2), i. e. the user activates the pyrolytic cleaning
program.
[0051] The pyrolytic cleaning program does not start immediately.
At first the actual water level L in the water reservoir 3 is
detected by the sensor element 4 and registered by the control unit
2. Then a comparison takes place in the control unit 2 between the
detected actual water level L and a stored value for the minimum
pyrolytic water level L.sub.MP.
[0052] The pyrolytic cleaning function is started then by the
control unit 2 if the actual water level L is equal or above the
minimum pyrolytic water level L.sub.MP.
[0053] If this is not the case the pyrolytic cleaning function is
not started by the control unit 2 but an alarm is issued to the
user by the control unit 2 to alert him that water must be filled
into the water reservoir 3.
[0054] It is possible that a message is outputted to the user
saying how much water has to be filled into the reservoir 3.
REFERENCE NUMERALS
[0055] 1 Steam oven 2 Control unit 3 Water reservoir 4 Sensor
element 5 Cooking cavity
6 Door
[0056] L Actual water level L.sub.MP Minimum pyrolytic water level
L.sub.OF Overfilled water level L.sub.MN Maximum water level for
normal steam cooking
* * * * *