[0001] The present invention relates to a refrigerator which performs the humidifying process
to keep the foodstuffs in the crisper fresh.
[0002] It is a very important requirement that the foodstuffs placed into the crisper in
the refrigerators are stored for a long time without losing their properties. The
relative humidity of hot and humid vegetables loaded into the crisper from outside
is considered as 100% due to their structure. When placed in the crisper having cold
and relatively dry air, the foodstuffs start to lose moisture rapidly due to the temperature
and vapor pressure difference between the outside temperature and steam pressure thereof
and the temperature and steam pressure after being placed in the crisper. This continues
until it is balanced. During the transition, sensors (RH-T) which measure relative
humidity and temperature can be misleading. This is caused because in the measurements
carried out after loading, the moisture lost by the loaded products is measured instead
of the actual relative humidity of the crisper environment. During the transition
and balancing, different types of humidification processes are required. In the state
of the art, the crisper cover provides passive control for moisture conservation.
However, due to the temperature difference of the newly loaded foodstuffs at ambient
temperature, evaporative moisture loss is high until it cools down. Moreover, depending
on the frequency of use of the crisper, the moisture loss of the vegetables during
the opening and closing thereof is also notable. Since the humidity lost cannot be
added to this area, this causes the foodstuffs in the crisper to lose liquid, to shrivel
and lose freshness. In the state of the art, moisture is added from outside to compensate
these moisture losses.
[0003] Moisture addition feature, which is generally performed by means of a water reservoir
and an atomizer which function as a steam generator, can be applied from the surface
or bottom of the water. Especially when moisture or steam generation is aimed by applying
current from the surface of the water, the water particles passing through the metal
plate holes turn into water vapor, and since it has sufficient speed, the need for
a fan is eliminated. This type of atomizers can be arranged in the horizontal or vertical
position. In this case, the atomizer is required to be located at the bottom of the
water reservoir or the water should be transferred to the atomizer. In such designs,
since the perforated atomizer is affected by the water pressure, leakage occurs in
the holes of the metal plate. In case of an increase in this leakage, water accumulates
in the crisper and the resulting water drops block the front of the atomizer. It is
observed that this leakage occurs when the atomizer is not operating and when the
system is not energized and does not occur when it is constantly energized. The amount
of leaking water varies depending on the pressure proportional to the level of the
water entering the atomizer. Therefore, performance decrease and cost increase occur
in the humidification processes realized without calculating the absolute humidity
of the foodstuffs in the crisper and without considering the water pressure coming
from the water reservoir.
[0004] In the state of the art German Patent Application No.
DE102013225716, a humidifier is disclosed, comprising a detachable water tank.
[0005] In the state of the art Chinese Patent Application No.
CN108224879, a design is disclosed, wherein the humidifier applies cold vapor onto the crisper
lid as the crisper lid is closed.
[0006] The aim of the present invention is to improve the water tightness at the region
where steam is discharged in refrigerator drawers having a steam generator.
[0007] The refrigerator realized in order to attain the aim of the present invention, explicated
in the claims, comprises a body; a protective cover which is disposed in the body;
a water reservoir; a drawer which is positioned under the protective cover and which
is used for loading fruits and vegetables; a steam generator which is disposed in
the drawer and which converts the water delivered from the water reservoir into steam
to be delivered into the drawer as steam; at least one ambient sensor which is disposed
in the drawer so as to detect the temperature and/or humidity level; and a control
unit which is disposed in the body, which adjusts the humidity level and which has
a memory. The water directly or indirectly delivered from the water reservoir by means
of preferably the atomizer disposed in the steam generator is separated into particles
in the form of steam and distributed into the drawer used as a crisper such that the
humidity level is increased. This arrangement is obtained by opening and closing the
steam generator at certain intervals, and there are a number of parameters which trigger
the steam generator such as opening/closing of the drawer especially thanks to the
ambient sensor data being used by the control unit.
[0008] Moreover, the refrigerator comprises the steam generator which is positioned vertically
in the body such that only one surface thereof is in contact with the water delivered
from the water reservoir. One surface, having a preferably perforated grill, of the
steam generator positioned vertically contacts the water horizontally. Depending on
the amount of water delivered to the steam generator and the time of closure, a certain
amount of pressure is applied towards the drawer. In order to ensure that the steam
generator completes a predetermined target operation time and under the condition
that the closure time is higher than the open time, the control unit carries out the
algorithm of operating the steam generator in case the specific humidity calculated
according to the data received from the ambient sensor after the target operation
time ensuring the predetermined number of closing/opening is reached is within the
lower and upper limits, and of operating the steam generator for a predetermined time
if the steam generator is not operated for a predetermined time in case said specific
humidity is not with the lower and upper limits. Two separate operation phases are
defined, and in the first phase, the steam generator is operated during the predetermined
open and closure times, and the value received from the ambient sensor is not taken
into consideration before the target time is completed. After the target time is completed,
it is checked whether the specific humidity is within the determined range according
to the data received from the ambient sensor, and the steps of delivering steam if
it is within the range and of not delivering steam if it is not are carried out. Thus,
independent of the different frequencies of drawer usage, the ideal level for the
absolute humidity is obtained and the water pressure hitting the steam generator is
decreased. In order to prevent condensation, the steam generator is enabled to be
operated by being opened/closed such that the closure time is higher than the open
time. Moreover, independent of the fullness level of the drawer, the control unit
can regulate the humidity level without any leaks and condensation in the steam generator.
All these technical advantages are provided only by carrying out an algorithm without
requiring any additional component or cost.
[0009] In an embodiment of the present invention, the refrigerator comprises the control
unit which resets the target operation time if the drawer is opened before reaching
the target operation time. Thus, independent of whether the user uses the drawer,
the algorithm performed by the control unit can continuously carry out the humidification
process.
[0010] In an embodiment of the present invention, the refrigerator comprises a water delivery
channel which transfers water from the water reservoir to the steam generator, and
a water level sensor which is disposed in the water delivery channel. The water delivery
channel connects the water reservoir to the steam generator. By means of the water
level sensor disposed in the water delivery channel, the water pressure acting on
the steam generator can be actively measured, and the control unit can process this
data.
[0011] In an embodiment of the present invention, the refrigerator comprises a control unit
which ensures that the steam generator is kept closed and open for predetermined time
according to the data received from the water level sensor in case the specific humidity
is not within the lower and upper limits. Since the formation of water drops which
causes leaks in the steam generator depends on pressure, the closure time is calculated
according to this assessment. Thus, by detecting the humidity values outside the lower
and upper limits determined by the control unit, any possibility of leak formation
is very quickly avoided, and the pressure is prevented by delivering steam into the
drawer.
[0012] In an embodiment of the present invention, the refrigerator comprises a valve which
is positioned between the water reservoir and the steam generator at the same level
as the steam generator with respect to the base of the drawer, and which is activated
as the steam generator is operated. Said component, which is preferably a solenoid
valve, is activated only when the atomizer is operated. Thus, excess water is prevented
from being delivered to the atomizer. Consequently, the water pressure is prevented
from affecting the atomizer and the pressure is minimized.
[0013] In an embodiment of the present invention, the refrigerator comprises a control unit
which enables the steam generator to be operated intermittently during the time determined
according to the data received from the water level sensor where the water remaining
between the valve and the steam generator is converted to steam by means of the steam
generator. Thus, by converting all or some of the water between the valve and the
steam generator after the valve is closed into mist, the water pressure acting on
the atomizer is decreased or eliminated.
[0014] A refrigerator realized in order to attain the aim of the present invention is illustrated
in the attached figures, where:
Figure 1 - is the perspective view of the refrigerator.
Figure 2 - is the perspective view of the drawer.
Figure 3 - is the top view of the drawer.
Figure 4 - is the sideways cross-sectional view of the drawer.
[0015] The elements illustrated in the figures are numbered as follows:
- 1. Refrigerator
- 2. Body
- 3. Protective cover
- 4. Water reservoir
- 5. Drawer
- 6. Steam generator
- 7. Ambient sensor
- 8. Control unit
- 9. Water delivery channel
- 10. Water level sensor
- 11. Valve
[0016] The refrigerator (1) comprises a body (2); a protective cover (3) which is disposed
in the body (2); a water reservoir (4); a drawer (5) which is positioned under the
protective cover (3) and which is used for loading fruits and vegetables; a steam
generator (6) which is disposed in the drawer (5) and which converts the water delivered
from the water reservoir (4) into steam to be delivered into the drawer (5) as steam;
at least one ambient sensor (7) which is disposed in the drawer (5) so as to detect
the temperature and/or humidity level; and a control unit (8) which is disposed in
the body (2), which adjusts the humidity level and which has a memory. The water directly
or indirectly delivered from the water reservoir (4) by hitting preferably the atomizer
disposed in the steam generator (6) is separated into particles in the form of steam
and distributed into the drawer (5) used as a crisper such that the humidity level
is increased. This arrangement is obtained by opening and closing the steam generator
(6) at certain intervals, and there are a number of parameters which trigger the steam
generator (6) such as opening/closing of the drawer (5) especially thanks to the ambient
sensor (7) data being used by the control unit (8).
[0017] Moreover, the refrigerator (1) comprises the steam generator (6) which is positioned
vertically in the body (2) such that only one surface thereof is in contact with the
water delivered from the water reservoir (4). One surface, having a preferably perforated
grill, of the steam generator (6) positioned vertically contacts the water horizontally.
Said region is also defined as the region where the atomizer contacts the water. Depending
on the amount of water delivered to the steam generator (6) and the closure time of
the steam generator (6), a certain amount of pressure is applied by the water towards
the drawer (5). In the algorithm, separate processing steps for precooling after loading
into the drawer (5) and the case where the humidity is balanced are performed. In
the first phase, the control unit (8) ensures that the steam generator (6) is closed/opened
for a predetermined number of times so as to complete a predetermined target operation
time under the condition that the closure time is higher than the open time. This
phase is designed as precooling and it is aimed to reach the balance in terms of humidity
and temperature. During a kind of duty cycle, the open-close commands given for the
steam generator (6) continue without taking any ambient sensor (7) data into account.
For example, a 30-minute cycle, where the steam generator (6) is closed for 5 minutes
and operated for 30 seconds, is defined, and the interior of the drawer (5) gets close
to the specific humidity-temperature levels. In order to prevent any condensation
problem by continuously delivering steam into the drawer (5), the closure time is
defined as higher than the open time. The control unit (8) ensures that the steam
generator (6) is operated in case the specific humidity calculated according to the
data received from the ambient sensor (7) is within the lower and upper limits after
the target time is completed, and ensures that the steam generator (6) is operated
for a predetermined time if the steam generator (6) is not operated for a predetermined
time in case said specific humidity is not with the lower and upper limits. For example,
when cold steam is not delivered into the drawer (5) for more than 10 minutes, cold
water steam is delivered for 40 seconds, and the water applying pressure to the steam
generator (6) is prevented from forming droplets. Two separate operation phases are
defined, and in the first phase, the steam generator (6) is operated during the predetermined
open and closure times, and the value received from the ambient sensor (7) is not
taken into consideration before the target time is completed. After said precooling
time and the target time are completed, it is checked whether the specific humidity
is within the determined range according to the data received from the ambient sensor
(7), and the steps of delivering steam if it is within the range and of not delivering
steam if it is not within the range are carried out. Thus, independent of the different
frequencies of drawer (5) usage, the ideal level for the absolute humidity is obtained
and the water pressure hitting the steam generator (6) is decreased. In order to prevent
possible condensation in the drawer (5), the steam generator (6) is enabled to be
operated in a open/close cycle where the closure time is preferably significantly,
for example 10 times, higher than the open time. Moreover, independent of the fullness
level of the drawer (5), the control unit (8) can regulate the humidity level without
any leaks and condensation in the steam generator (6). All these technical advantages
are provided only by carrying out an algorithm without requiring any additional component
or cost.
[0018] In an embodiment of the present invention, the refrigerator (1) comprises the control
unit (8) which resets the target operation time if the drawer (5) is opened before
reaching the target operation time. By resetting the memory of the control unit (8),
in case of any user invention, the precooling phase is restarted, and the ambient
sensor (7) data is taken into account at a delayed time. Thus, independent of whether
the user uses the drawer (5), the algorithm performed by the control unit (8) can
continuously carry out the humidification process.
[0019] In an embodiment of the present invention, the refrigerator (1) comprises a water
delivery channel (9) which transfers water from the water reservoir (4) to the steam
generator (6), and a water level sensor (10) which is disposed in the water delivery
channel (9). The water delivery channel (9) connects the water reservoir (4) to the
steam generator (6), and partially determines the pressure applied by the water onto
the atomizer. By means of the water level sensor (10) disposed in the water delivery
channel (9), the water pressure acting on the steam generator (6) can be actively
measured, and the control unit (8) can process this data.
[0020] In an embodiment of the present invention, the refrigerator (1) comprises a control
unit (8) which ensures that the steam generator (6) is kept closed and open for predetermined
time according to the data received from the water level sensor (10) in case the specific
humidity is not within the lower and upper limits. Since the formation of water drops
which causes leaks in the steam generator (6) depends on pressure, the closure time
is calculated according to this assessment. Since the amount of drops formed decreases
as the water level decreases, the closure time increases or the open time is reduced
while the closure time remains constant. By detecting the humidity values outside
the lower and upper limits determined by the control unit (8), any possibility of
leak formation is very quickly avoided, and the unwanted pressure is prevented by
delivering steam into the drawer (5).
[0021] In an embodiment of the present invention, the refrigerator (1) comprises a valve
(11) which is positioned between the water reservoir (4) and the steam generator (6)
at the same level as the steam generator (6) with respect to the base of the drawer
(5), and which is activated as the steam generator (6) is operated. Said component,
which is preferably a solenoid valve, is activated only when the atomizer is operated.
The vertical distance between the atomizer and the valve (11) is limited within the
range of 0-100 mm, and thus, excess water is prevented from being delivered onto the
atomizer due to decreasing pressure. In other words, the water pressure is prevented
from affecting the atomizer and the pressure is minimized.
[0022] In an embodiment of the present invention, the refrigerator (1) comprises a control
unit (8) which enables the steam generator (6) to be operated intermittently during
the time determined according to the data received from the water level sensor (10)
where the water remaining between the valve (11) and the steam generator (6) is converted
to steam by means of the steam generator (6). Thus, by converting all or some of the
water between the valve (11) and the steam generator (6) after the valve (11) is closed
into mist, the water pressure acting on the atomizer is decreased or eliminated. The
control unit (8) calculates the time of converting the water remaining between the
solenoid valve (11) and the atomizer into mist. This time approximately represents
the time difference to be applied between the operation of the atomizer and the operation
of the valve (11). By converting all or some of the water between the valve (11) and
the atomizer after the valve (11) is closed into mist, the water pressure acting on
the atomizer is decreased or eliminated.
[0023] In the refrigerator (1) of the present invention, the water tightness problem of
the steam generators (6) disposed in the drawer (5) is eliminated without using any
additional component or cost, and the user satisfaction for all the steam generators
(6) positioned vertically is increased.
1. A refrigerator (1) comprising a body (2); a protective cover (3) which is disposed
in the body (2); a water reservoir (4); a drawer (5) which is positioned under the
protective cover (3) and which is used for loading fruits and vegetables; a steam
generator (6) which is disposed in the drawer (5) and which converts the water delivered
from the water reservoir (4) into steam to be delivered into the drawer (5) as steam;
at least one ambient sensor (7) which is disposed in the drawer (5) so as to detect
the temperature and/or humidity level; and a control unit (8) which is disposed in
the body (2), which adjusts the humidity level and which has a memory,
characterized by the steam generator (6) which is positioned such that only one surface thereof is
in contact with the water delivered from the water reservoir (4), and
a control unit (8) which ensures that
- the steam generator (6) is closed/opened for a predetermined number of times so
as to complete a predetermined target operation time under the condition that the
closure time is higher than the open time,
- the steam generator (6) is operated in case the specific humidity calculated according
to the data received from the ambient sensor (7) is within the lower and upper limits
after the target operation time is completed, and
- the steam generator (6) is operated for a predetermined time if the steam generator
(6) is not operated for a predetermined time in case said specific humidity is not
with the lower and upper limits.
2. A refrigerator (1) as in Claim 1, characterized by the control unit (8) which resets the target operation time if the drawer (5) is
opened before reaching the target operation time.
3. A refrigerator (1) as in Claim 1 or 2, characterized by a water delivery channel (9) which transfers water from the water reservoir (4) to
the steam generator (6), and a water level sensor (10) which is disposed in the water
delivery channel (9).
4. A refrigerator (1) as in Claim 3, characterized by a control unit (8) which ensures that the steam generator (6) is kept closed and
open for predetermined time according to the data received from the water level sensor
(10) in case the specific humidity is not within the lower and upper limits.
5. A refrigerator (1) as in any one of the above claims, characterized by a valve (11) which is positioned between the water reservoir (4) and the steam generator
(6) at the same level as the steam generator (6) with respect to the base of the drawer
(5), and which is activated as the steam generator (6) is operated.
6. A refrigerator (1) as in Claim 5, characterized by a control unit (8) which enables the steam generator (6) to be operated intermittently
during the time determined according to the data received from the water level sensor
(10) where the water remaining between the valve (11) and the steam generator (6)
is converted to steam by means of the steam generator (6).