U.S. patent application number 15/378113 was filed with the patent office on 2017-05-04 for method for operating a dishwasher.
This patent application is currently assigned to BSH Hausgerate GmbH. The applicant listed for this patent is Michael Georg Rosenbauer. Invention is credited to Michael Georg Rosenbauer.
Application Number | 20170119231 15/378113 |
Document ID | / |
Family ID | 41722005 |
Filed Date | 2017-05-04 |
United States Patent
Application |
20170119231 |
Kind Code |
A1 |
Rosenbauer; Michael Georg |
May 4, 2017 |
METHOD FOR OPERATING A DISHWASHER
Abstract
A method for operating a dishwasher is provided. During a first
phase, the dishwasher is operated with a first fluid quantity that
is heated by a desorption process of a drying material. The first
fluid quantity is increased to a second fluid quantity by adding a
third fluid quantity that is stored in the drying material. During
a second phase, the dishwasher is operated with the second fluid
quantity. The first and second fluid quantities are circulated by a
circulation pump during the first and second phases, respectively.
The circulation pump is operated at a rotational speed that is
higher during the second phase than during the first phase.
Inventors: |
Rosenbauer; Michael Georg;
(Reimlingen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rosenbauer; Michael Georg |
Reimlingen |
|
DE |
|
|
Assignee: |
BSH Hausgerate GmbH
Munich
DE
|
Family ID: |
41722005 |
Appl. No.: |
15/378113 |
Filed: |
December 14, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13058542 |
Feb 11, 2011 |
|
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PCT/EP2009/060232 |
Aug 6, 2009 |
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15378113 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A47L 15/4285 20130101;
A47L 2601/02 20130101; A47L 15/4291 20130101; Y02B 40/00 20130101;
Y02B 40/44 20130101; A47L 15/4225 20130101; A47L 15/481 20130101;
A47L 15/0007 20130101; A47L 15/486 20130101 |
International
Class: |
A47L 15/42 20060101
A47L015/42; A47L 15/48 20060101 A47L015/48; A47L 15/00 20060101
A47L015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 11, 2008 |
DE |
10 2008 043 551.1 |
Aug 27, 2008 |
DE |
10 2008 039 888.8 |
Claims
1. A method for operating a dishwasher, the method comprising:
during a first phase, operating the dishwasher with a first
quantity of fluid and heating the first quantity of fluid by a
desorption process of a drying material, wherein the first quantity
of fluid is increased to a second quantity of fluid by adding a
third quantity of fluid stored in the drying material; and during a
second phase, operating the dishwasher with the second quantity of
fluid; wherein the first quantity of fluid and the second quantity
of fluid are circulated by a circulation pump during the first
phase and the second phase, respectively; and wherein the
circulation pump is operated at a rotational speed that is higher
during the second phase than during the first phase.
2. The method of claim 1, wherein the dishwasher is a household
dishwasher.
3. The method of claim 1, wherein the third quantity of fluid is
between 0.11 and 11.
4. The method of claim 3, wherein the third quantity of fluid is
between 0.21 and 0.51.
5. The method of claim 1, wherein the drying material is suitable
for exothermic drying.
6. The method of claim 5, wherein the drying material is suitable
for drying cleaned items.
7. The method of claim 5, wherein the drying material is a
reversibly dehydratable drying material of a sorption drying
system.
8. The method of claim 7, wherein the reversibly dehydratable
drying material is zeolite.
9. The method of claim 1, wherein, during the second phase, at
least one of the first, second, and third quantity of fluid is
heated by a water heater.
10. The method of claim 1, wherein, during the second phase, the
circulation pump is operated at least periodically in a true
running state.
11. The method of claim 1, wherein, during a program step of a
plurality of program steps with cleaning action, the third quantity
of fluid stored in the drying material is added.
12. The method of claim 11, wherein the program step is a wash
program step with addition of detergent.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional, under 35 U.S.C. .sctn.121,
of U.S. application Ser. No. 13/058,542, filed Feb. 11, 2011, which
is a U.S. national stage application under 35 U.S.C. .sctn.371 of
PCT/EP2009/060232, filed Aug. 6, 2009, which designated the United
States; this application also claims the priority, under 35 U.S.C.
.sctn.119, to German Application No. 10 2008 043 551.1, filed Nov.
7, 2008 and to German Application No. 10 2008 039 888.8, filed Aug.
27, 2008.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a method for operating a
dishwasher, in particular a household dishwasher.
[0003] Dishwashers are known which run through wash programs
comprising a plurality of program steps, such as prewash, wash,
intermediate rinse, final rinse and drying of the items being
washed for example. During some of these program steps, such as
prewash or wash for example, fluid is applied to the items being
washed to detach dirt, the fluid being heated by means of a heating
means configured as a flow-through heater to enhance the cleaning
action and detergent is added during a program step wash for
example.
BRIEF SUMMARY OF THE INVENTION
[0004] The object of the invention is to improve the cleaning
performance further.
[0005] The invention is based on a method for operating a
dishwasher, in particular a household dishwasher, in which during
at least a first phase operation takes place with a first
predefined quantity of fluid and during a second phase operation
takes place with a second predefined quantity of fluid, the first
quantity of fluid being less than the second quantity of fluid.
[0006] According to the invention provision is made for a quantity
of fluid stored in a fluid reservoir to be added to increase the
first quantity of fluid to the value of the second quantity of
fluid. In a program step with a washing action, such as the program
step wash for example, this allows the spray pressure of the fluid
coming out of the spray arms of the dishwasher to be increased by
increasing the speed of a circulation pump, thereby improving
cleaning performance without fluid, e.g. water, additionally having
to be taken from a house-side water supply system. This conserves
natural resources. It is possible here for fluid, such as water,
for example fresh water or even used wash liquor, to be stored in
an intermediate manner in the fluid reservoir in the time period
between two uses of the dishwasher, in other words between two wash
program runs, each consisting of a plurality of program steps, such
as prewash, wash, intermediate rinse, final rinse and/or drying for
example.
[0007] In one development provision is made for a drying means to
be used as the fluid reservoir. This allows fluid to be stored in
an intermediate manner and/or to be heated by waste heat and/or
optionally also to be recycled, so that the overall water
requirement can be reduced.
[0008] In one development provision is made for essentially a
quantity of fluid of between 0.1 and 1 1, in particular between 0.2
and 0.5 1 to be added from the drying means. This means that a
quantity of water stored in the drying means during a drying
process can be recycled essentially in totality to improve the
cleaning performance.
[0009] In one development provision is further made for a drying
means suitable for exothermic drying to be used, in particular for
drying cleaned items.
[0010] To this end in one development provision is made for a
reversibly dehydratable drying means, in particular zeolite, of a
sorption drying system to be used. This drying material features a
high water absorption capacity and good reversible
dehydratability.
[0011] In one development provision is further made for a quantity
of fluid to be heated by a desorption process of the drying means
during the first phase. This allows particularly energy-efficient
cleaning with heated fluid, e.g. with water containing
detergent.
[0012] In one development provision is further made for a quantity
of fluid to be heated by a water heater during the second phase.
This allows rapid further heating to higher temperatures, thereby
improving the cleaning performance further.
[0013] In one development provision is made for a quantity of fluid
to be circulated by means of a circulation pump during the first
phase and the second phase, with the circulation pump being
operated at a higher speed during the second phase than during the
first phase. This allows the cleaning performance to be improved
significantly, particularly during the second phase.
[0014] In one development provision is made for the circulation
pump to be operated at least periodically in the true running state
during the second phase. This allows particularly quiet operation,
since in the true running state the circulation pump does not take
in any air.
[0015] The object of the invention is further achieved by a
dishwasher, in particular a household dishwasher, in particular
with a sorption drying system, which at least during a first phase
performs an operation with a first predefined quantity of fluid and
during a second phase performs an operation with a second
predefined quantity of fluid, the first quantity of fluid being
less than the second quantity of fluid, with provision being made
according to the invention for it to be possible for a stored
quantity of fluid to be added to the first quantity of fluid from a
drying means, to increase the first quantity of fluid to the value
of the second quantity of fluid.
[0016] Other developments of the inventive dishwasher are set out
in the subclaims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention and its developments are described in more
detail below with reference to drawings, in which:
[0018] FIG. 1 shows a schematic diagram of an exemplary embodiment
of an inventive dishwasher with a sorption drying system,
[0019] FIG. 2 shows a schematic diagram of the temperature profile
during a first exemplary embodiment of an inventive wash program
run,
[0020] FIG. 3 shows a schematic diagram of the temperature profile
of a further, second exemplary embodiment of an inventive wash
program run, and
[0021] FIG. 4 shows a schematic diagram of the temperature profile
of a further, third exemplary embodiment of an inventive wash
program run.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE PRESENT
INVENTION
[0022] Reference is made first to FIG. 1.
[0023] A dishwasher GS, configured in the present exemplary
embodiment as a household dishwasher, has an interior IR serving as
a washing container, which can be opened and closed for loading and
unloading by means of a door (not shown) hinged to the dishwasher
GS in a pivotable manner Racks GK for holding items to be washed
are provided in the interior IR of the dishwasher GS, it being
possible to pull said racks GK out of the interior IR of the
dishwasher GS to facilitate loading and unloading.
[0024] To clean the items to be washed supported in the racks GK,
means for applying fluid to the items to be washed configured as
spray arms SA are provided in the interior IR of the dishwasher GS,
it being possible for the fluid to be for example water mixed with
detergents or rinse aid, in order thus to bring about a cleaning
action or streak-free drying. The fluid flowing off the items being
washed collects in a pump sump PS, which is disposed in the base
region of the interior IR of the dishwasher GS.
[0025] The spray arms SA are connected in a fluid-conducting manner
by way of a supply line ZL to a circulation pump UP, which is
disposed along with other components of the dishwasher GS in a base
assembly BO beneath the interior IR of the dishwasher GS. During
operation, i.e. when the circulation pump UP is running, the
circulation pump UP sucks up the fluid collected in the pump sump
PS and conveys it through the supply line ZL to the spray arms SA.
To heat the fluid circulated by operation of the circulation pump
UP, the circulation pump has an integrated water heater WZ for
heating the fluid. Alternatively a separate flow-through heater or
another water heater can be provided in addition to the circulation
pump UP. A drain pump LP is provided to empty the interior IR of
the dishwasher GS, being likewise connected in a fluid-conducting
manner to the pump sump PS and being able to be connected by way of
a discharge line EL to a house-side waste water disposal
network.
[0026] The dishwasher GS further features a sorption drying system,
which can be used to dry cleaned items disposed in the racks GR at
the end of a wash program run. To this end a sorption container SB
is provided in the base assembly BO, being connected in an
air-conducting manner to an inlet EI by way of an air channel LK,
with a fan LT being provided to generate a forced throughflow. To
convey the air sucked in through the inlet EI and conveyed into the
sorption container by the fan LT back into the interior IR of the
dishwasher GS, an outlet opening AU is provided in the base region
of the interior IR of the dishwasher GS.
[0027] To bring about drying of cleaned items, the fan LT sucks in
air from the interior IR of the dishwasher GS, conducts it through
the sorption container SB and back through the outlet opening AU
into the interior IR of the dishwasher GS. In order to dry the
circulated air in this process, a drying means for performing
exothermic drying is provided in the sorption container SB. This is
a reversibly dehydratable drying material, e.g. zeolite, that
absorbs water due to its hydroscopic nature, in which process
thermal energy is simultaneously released. This released energy
causes the circulated air to be heated, thereby raising the
moisture absorption capacity of the circulated air. At the end of a
drying process a quantity of fluid is stored in the drying material
ZEO.
[0028] To restore the absorption capacity of the drying means ZEO
for a new wash program run, an air heater HZ is provided, which is
disposed in the sorption container SB in the present exemplary
embodiment. It is however also possible to dispose an air heater
outside the sorption container SB, e.g. in the air channel LK, to
bring about heating of the air conveyed into the sorption container
SB. An air flow generated using the fan LT is heated to drive out
the quantity of fluid stored in the drying material ZEO, so that
the drying material ZEO can be heated to temperatures at which the
quantity of water stored in the drying material ZEO can be released
again.
[0029] We will now look at FIGS. 2 to 4.
[0030] To wash and dry items to be washed, dishwashers GS run
through wash programs that consist of a plurality of program steps
that are run through one after the other. Such a program can
consist of the program steps prewash V, wash R, intermediate rinse
Z, final rinse K and drying T, it being possible also to omit
individual program steps such as prewash V or intermediate rinse Z
while it is also possible to run individual program steps a number
of times, e.g. intermediate rinse Z. During the prewash V water
with no detergent added for example is applied to the items to be
washed, this taking place either with unheated water or with water
heated using a heater. To this end water that has been stored in a
water tank (not shown) can be used. Such a water tank can be
connected in a thermally conducting manner to the environment of
the dishwasher, so that fluid stored in an intermediate fashion in
the water tank, e.g. water from a house-side supply system, can be
heated to ambient temperature. In the washing step R the items to
be washed are cleaned by the application of water containing
detergents, i.e. detergent is added during the washing step. The
fluid is also heated in order thus to enhance the cleaning action
of the detergent. The washing step R here is made up of a heating
phase P1, P2, in which the fluid in the dishwasher GS is heated by
heating means, until a predefined maximum temperature is reached
and a subsequent post-wash phase, during which the heating means
are switched off and the slowly cooling fluid is circulated by
means of the circulation pump UP. In the program step intermediate
rinse Z fluid is applied to the items to be washed, to convey dirt
residues out of the dishwasher GS. The next program step is the
final rinse K in preparation for the drying program step T, in
which water containing rinse aid is circulated by means of the
circulation pump and applied to the now cleaned items by way of the
spray arms SA. The program step drying T then follows, in which
fluid is no longer applied to the items but operation of the fan LT
causes an air flow circulating through the interior IR of the
dishwasher GS and the sorption container SB to be generated. A full
or at least partial fluid change can be effected between the
individual program steps, in other words the dishwasher GS is
emptied by means of the drain pump LP and the discharge line EL and
refilled by a supply line (not shown) that establishes a connection
to a house-side supply system.
[0031] With the wash program sequence according to FIG. 2 fluid is
only heated in the program step wash R. Starting from a start
temperature T0 during a first phase P1 the fluid circulated using
the circulation pump UP is first heated by the air heater HZ in the
sorption container SB to a maximum temperature T1, with the fan LT
generating an air flow circulating through the interior IR of the
dishwasher GS at the same time. The air heater HZ heats the drying
material ZEO in the sorption container SB to temperatures at which
the quantity of water stored in the drying material ZEO is driven
out of the drying material ZEO and conveyed through the outlet
opening AU in the interior IR of the dishwasher GS. This quantity
of fluid is heated by the action of the air heater HZ and when
mixed with the fluid already circulated by means of the circulation
pump UP heats the overall quantity of fluid in the interior IR of
the dishwasher GS.
[0032] The use of the air heater HZ during the program step wash R
to heat up to the first temperature T1 ensures that the drying
material ZEO can be reliably and completely desorbed by the
circulation of relatively cold and dry air from the interior IR of
the dishwasher GS. Instead of a rigid wash program sequence, in
which a desorption process is performed in a first program segment,
in which fluid is heated, in an alternative exemplary embodiment
provision can also be made for evaluating parameters that influence
the desorption process, to determine the time point for performing
desorption. These parameters can be the air temperature and the
water intake temperature. For example a desorption process can take
place in a program step wash or final rinse or even during the
program step prewash if expedient.
[0033] During desorption by means of the air heater HZ the outlet
opening AU in the interior IR of the dishwasher GS is cooled, to
ensure that the heat output of the air heater HZ does not cause
excessive heating of the outlet opening HZ with overheating
damage.
[0034] To this end during operation of the air heater HZ, i.e.
during phase P1 for example, the circulation pump UP is operated in
such a manner that fluid is conveyed by the circulation pump from
the pump sump PS through the supply line to the spray arms SA. This
causes the spray arms SA to rotate and the spraying of the outlet
opening AU, in particular a cap covering the outlet opening AU,
with fluid brings about cooling of the same.
[0035] In a next phase P2 of the program step wash R the water
heater WZ heats the quantity of fluid from the first temperature T1
to the second temperature T2.
[0036] To enhance the cleaning action during the program step wash
R provision is made to increase the spray pressure of the jets of
water coming out of the spray arms SA by increasing the speed of
the circulation pump UP. To this end during the program step wash R
in the post-wash phase NA the quantity of fluid circulated by the
circulation pump UP is increased by means of a top-up step, for
example at time point t1 (see FIG. 2) and the speed of the
circulation pump UP is then increased, e.g. continuously until the
circulation pump again operates in true running conditions, in
other words does not take in air bubbles during operation, which
reduces the delivery rate of the circulation pump UP and causes
unwanted noise to develop. It thus becomes possible to take account
of the quantity of fluid that was stored in the drying material ZEO
and is released during desorption when setting the quantity of
top-up fluid, thereby reducing the overall water requirement whilst
still improving cleaning performance.
[0037] A run-off phase AB is provided between the program step
final rinse K and the program step drying T (see FIG. 2), during
which fluid adhering to the washed items, i.e. water containing
rinse aid, can run off the items in the dishwasher due to gravity
and collect in the pump sump PS of the interior IR of the
dishwasher GS. This reduces the quantity of fluid to be absorbed by
the sorption drying system and thus the duration of the program
step drying T.
[0038] Before this run-off phase AB, in other words at the end of
the program step final rinse K, a pump-out process takes place, in
which the fluid containing rinse aid is conveyed by means of the
drain pump LP through the discharge line EL into a house-side waste
water disposal system. The run-off phase AB follows, during which
neither the circulation pump UP nor the drain pump LP, nor the fan
LT nor any of the above-mentioned heaters HZ, WZ is in operation.
After the end of this run-off phase AB the program step drying T
starts by starting up the fan LT, so that an air flow circulating
through the interior IR of the dishwasher and the sorption
container SB is generated to dry the washed items in the racks GK.
At the end of the program step drying T a further pump-out process
takes place by means of the drain pump LP, by means of which a
residual quantity of fluid is conveyed out of the dishwasher GS
through the discharge line EL into a house-side waste water
disposal system. Alternatively provision can also be made to
perform a further pump-out process additionally or alternatively at
the start of the program step drying T.
[0039] In the wash program according to FIGS. 3 and 4 fluid is
heated in the first of the program steps, the program step prewash
V. To this end the air heater HZ heats fluid from a start
temperature T0 during a phase P1' to a temperature T1', in which,
as described above, an air flow circulating through the interior IR
of the dishwasher GS and the sorption container SB is generated by
means of the fan LT. Once the temperature T1' is reached, the air
heater HZ is deactivated. At this time point the drying material
ZEO is not yet completely desorbed, in other words a residual
quantity of water is stored in the drying material ZEO. To drive
this residual quantity of water out of the drying material ZEO and
thus have a drying material ZEO with full water absorption capacity
available again at the start of the program step drying T, in the
next program step wash R the fluid is first heated by means of the
air heater HZ to a temperature T1 and then by operation of the
water heater to the temperature T2. In other words the desorption
phase of the drying means ZEO in the sorption container SB is split
into two and divided between two program steps, namely the program
step prewash V and the program step wash R.
[0040] To enhance the cleaning action by further increasing the
temperature, provision can be made for a further phase P3 (see FIG.
3), during which the fluid is further heated to a temperature T3
using the water heater WZ.
[0041] To improve the drying result at the end of the program step
drying T, with the exemplary embodiments according to FIGS. 3 and 4
provision is made for the fluid to be heated during the final rinse
step K. To this end during a phase P4 fluid, which is water or
water containing rinse aid, is heated to a temperature T4 by means
of the water heater WZ. Alternatively, instead of the water heater
the air heater HZ can also be used, in order for example to
complete a desorption that has not yet been fully performed during
the program run. Additionally during a further phase P5 further
heating of the fluid to a temperature T5 can take place, to improve
drying using the sorption drying system.
* * * * *