U.S. patent application number 11/629892 was filed with the patent office on 2008-02-21 for domestic refrigerating appliance with an evacuatable storage compartment.
This patent application is currently assigned to BSH Bosch und Siemens Hausgerate GmbH. Invention is credited to Adolf Feinauer.
Application Number | 20080041085 11/629892 |
Document ID | / |
Family ID | 34972970 |
Filed Date | 2008-02-21 |
United States Patent
Application |
20080041085 |
Kind Code |
A1 |
Feinauer; Adolf |
February 21, 2008 |
Domestic Refrigerating Appliance with an Evacuatable Storage
Compartment
Abstract
A domestic refrigerating appliance comprising a heat-insulated
inner area, a refrigerating machine using a thermodynamic cycle for
refrigerating the inner area, a vacuum pump and a first compartment
which is separated from the inner area and which can be evacuated
by means of the vacuum pump. The vacuum pump produces pressure
inside the first compartment, said pressure being lower than the
vapor pressure of water at the temperature of the compartment.
Inventors: |
Feinauer; Adolf; (Giengen,
DE) |
Correspondence
Address: |
BSH HOME APPLIANCES CORPORATION;INTELLECTUAL PROPERTY DEPARTMENT
100 BOSCH BOULEVARD
NEW BERN
NC
28562
US
|
Assignee: |
BSH Bosch und Siemens Hausgerate
GmbH
Carl-Wery-Strasse 34
Munich
DE
81739
|
Family ID: |
34972970 |
Appl. No.: |
11/629892 |
Filed: |
July 22, 2005 |
PCT Filed: |
July 22, 2005 |
PCT NO: |
PCT/EP05/53583 |
371 Date: |
December 15, 2006 |
Current U.S.
Class: |
62/268 |
Current CPC
Class: |
F25D 2317/043 20130101;
F25D 17/042 20130101; F25D 21/14 20130101; F25D 31/00 20130101 |
Class at
Publication: |
062/268 |
International
Class: |
F25B 19/02 20060101
F25B019/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 23, 2004 |
DE |
10 2004 035 730.7 |
Claims
1-12. (canceled)
13. A domestic refrigerating appliance comprising: a heat-insulated
inner area; a refrigerating machine using a thermodynamic cycle for
refrigerating the inner area; a vacuum pump; a first evacuatable
compartment which is separated from the inner area and which can be
evacuated by means of the vacuum pump; and wherein the vacuum pump
produces a final pressure within the first compartment below the
vapor pressure of water at the temperature within the first
compartment.
14. The domestic refrigerating appliance according to claim 13,
wherein the final pressure is below 6 mbar.
15. The domestic refrigerating appliance according to claim 13,
further comprising an evacuation connection between the first
compartment and the vacuum pump, the vacuum pump developing a
suction capacity of at least 0.5 l/s at a pressure prevailing in
the first compartment below the vapor pressure of water at the
temperature of the compartment.
16. The domestic refrigerating appliance according to claim 13,
further comprising a second evacuatable compartment which is in
direct thermal contact with the first compartment.
17. The domestic refrigerating appliance according to claim 16,
wherein the first compartment can be evacuated independently of the
second compartment.
18. The domestic refrigerating appliance according to claim 17,
wherein the suction capacity of the pump at an evacuation
connection of the second compartment is lower than at that of the
first compartment.
19. The domestic refrigerating appliance according to claim 16,
wherein the first and the second compartments are surrounded by a
common wall.
20. The domestic refrigerating appliance according to claim 13,
wherein the first compartment contains a hydrophilic porous
material.
21. The domestic refrigerating appliance according to claim 13,
further comprising a condensate trap is connected to the vacuum
pump.
22. The domestic refrigerating appliance according to claim 21,
further comprising an evaporation tray into which the condensate
trap drains.
23. The domestic refrigerating appliance according to claim 22,
wherein the evaporation tray is heated by heat loss of the
refrigerating machine.
24. The domestic refrigerating appliance according to claim 13,
wherein the domestic refrigerating appliance includes a
refrigerator.
Description
[0001] The present invention relates to a domestic refrigerating
appliance comprising a heat-insulated inner area, a refrigerating
machine using a thermodynamic cycle for refrigerating the inner
area, a vacuum pump and a first compartment which is separated from
the inner area and which can be evacuated by means of the vacuum
pump. Such a refrigerating appliance is described, for example, in
DE 198 58 254 A1.
[0002] The purpose of evacuating the compartment is to improve the
keeping properties of the food stored therein. For this purpose, a
uniformly low pressure must be maintained during the storage time.
This pressure is usually of the order of magnitude of a few percent
of atmospheric pressure. Its lower limit is determined by the
design and quality of the vacuum pump, by the conduction capacity
of conduits between the compartment and the pump, by the imperfect
seal of the compartment and the conduits etc. Lower pressures can
be achieved technically without any difficulties but require
expenditure which increases the manufacturing costs of the
appliance. Since the maximum attainable storage duration of chilled
goods in a vacuum compartment only increases negligibly when the
final pressure in the compartment is reduced, for example, below 1%
of atmospheric pressure, there is generally no interest in
achieving pressures of this order of magnitude in the vacuum
compartment.
[0003] It is the object of the present invention to expand the
possible uses of a refrigerating appliance of the type specified
above.
[0004] This object is achieved by a refrigerating appliance having
the features of claim 1. If the vacuum pump in the first
compartment (10) produces a final pressure below the vapor pressure
of water at the temperature of the compartment (10), water present
in the compartment comes to the "boil". The vaporization of the
water at low pressure results in cooling of itself or cooling of
chilled goods in thermal contact with the water so that a cooling
temperature below that provided by the refrigerating machine to the
inner area can be reached in the evacuatable compartment.
[0005] It is particularly preferable if the possibility is thereby
provided to cool the compartment below the freezing point of water
even if the temperature of the remaining inner area of the
refrigerating appliance is higher. For this purpose, the vacuum
pump must be capable of producing a pressure of 6 mbar or less in
the compartment.
[0006] The refrigerating capacity depends on the volume flow
extracted from the compartment. In order to achieve a refrigerating
capacity which is useful in practice, the vacuum pump should
develop a suction capacity of at least 0.5 l/s at the evacuation
connection of the first compartment whilst in the first
compartment, a pressure below the vapor pressure of water prevails
at the temperature of the compartment.
[0007] Chilled goods other than water can be accommodated in a
second evacuatable compartment which is in direct thermal contact
with the first compartment.
[0008] This second compartment can preferably be evacuated
independently of the first compartment. i.e. gas contained therein
can be pumped away whilst the first compartment is separated from
the pump or conversely. Thus, for example, after loading with
chilled goods, it is possible to initially evacuate both
compartments and after a certain time has elapsed or a certain
pressure has been reached, the second compartment can be separated
from the pump whether to have more suction capacity available for
the first or to avoid drying out of the chilled goods in the second
compartment by continuously pumping away the water vapor released
by said chilled goods. It is also feasible to evacuate merely the
second compartment and then connect the pump to the first
compartment to start the refrigeration.
[0009] Since water vapor should not be released to such a great
extent in the second compartment as in the first compartment, the
suction capacity of the pump at an evacuation connection of the
second compartment can be kept lower than at that of the first
compartment.
[0010] In order to achieve direct thermal contact between the two
compartments and to ensure that these are more closely thermally
coupled to one another than to a remainder of the inner area, both
compartments are preferably surrounded by a common wall.
[0011] The first compartment can preferably contain a hydrophilic
porous material in order to provide a large surface on which water
can evaporate.
[0012] In order to avoid water vapor pumped away by the vacuum pump
re-condensing at an unsuitable location and/or to trap oil vapor of
the vacuum pump, a condensate trap can be connected to the vacuum
pump.
[0013] Conventionally, most refrigerating appliances comprise an
evaporation tray which is supplied with water of condensation which
becomes deposited on the evaporator of the refrigerating machine in
the inner area of the refrigerating appliance. Such an evaporation
tray can also be used for draining the condensation trap.
[0014] Further features and advantages of the invention are
obtained from the following description of exemplary embodiments
with reference to the appended figures. In the figures:
[0015] FIGS. 1 and 2 each show exemplary embodiments of the
refrigerating appliance according to the invention in a schematic
view.
[0016] FIG. 1 shows a schematic section through a domestic
refrigerating appliance comprising a body 1 and a door 2 hinged to
the body 1, which enclose a heat-insulated inner area 3. A cavity 4
is formed in a lower rear corner of the body 1 and accommodates the
compressor 5 of a refrigerating machine of the refrigerator in a
manner known per se. The compressor 5 supplies a condenser 6
attached to the rear wall of the body 1 with refrigerant at high
pressure; from there the refrigerant reaches an evaporator 7
attached to the rear wall of the inner area 3 via a constriction
and flows back from said evaporator to the compressor 5.
[0017] The cavity 4 also accommodates a vacuum pump 8 whose suction
intake is connected to an evacuatable compartment 10 via a pipe 9.
The compartment 10 is shown here approximately at half the height
of the inner area 3 but can be placed at any other location; in
particular, attachment near the bottom of the inner area should be
considered in order to keep the pipe 9 short and thus enable
effective evacuation of the compartment 10.
[0018] On its front side facing the door 2, the compartment 10 has
a flap 11 which can be opened in the non-evacuated state of the
compartment 10 in order to load or unload chilled goods. The flap
11 and the other walls of the compartment 10 each contain an
insulation layer which thermally insulates the interior of the
compartment 10 from the surrounding inner area 3.
[0019] A cooking pot 12 with a loose lid is shown as an example in
the interior of the compartment 10. A water-impregnated cloth 13 is
slung around the pot 12.
[0020] When the compartment 4 is evacuated, air escapes from the
interior of the pot 12 since its lid is only resting loosely
thereon. However, when the pressure in the compartment 10
approaches the final pressure in the range of a few millibar or
fractions of millibar, hardly any gas escapes from the pot 12 so
that a pressure substantially corresponding to the vapor pressure
of the water at the temperature of the pot 12 is established in its
interior if it contains water-containing chilled goods. This
therefore avoids excessive drying out of the contents of the pot.
If the pressure in the compartment falls to the vapor pressure of
the water during evacuation of the compartment 10, the water with
which the cloth 13 is impregnated begins to "boil".
[0021] When the temperature of the compartment 10 is 0.degree. C.,
the vapor pressure of the water is 6 mbar. One litre of water vapor
at this pressure weighs 5 mg, and if the heat of evaporation of the
water is 2250 J/g, 11 J is required to produce this. If the pump at
the suction intake 14 of the compartment 10 develops a suction
capacity of 1 l/s at the inlet of the pipe 9, this extracts 11 J of
heat from the compartment contents per second, i.e. it develops a
cooling capacity of 11 W. If losses of refrigerant via the walls of
the compartment 10 are neglected, this means that if the melting
heat of the water is 335 J/g, 50 minutes is required to make 100 g
of water freeze from 0.degree. C. Thus, for example, it is possible
to produce ice cubes with the refrigerator according to the
invention by placing an ice cube tray in the compartment 10 and
evacuating this without the refrigerating machine needing to be
capable of producing temperatures below 0.degree. C. in the inner
area 3. By setting the suction capacity of the pump to be higher at
the connection 14, shortened cooling times proportional to the
suction capacity can be achieved as required.
[0022] A condensate trap 16 is connected to a high-pressure
connection of the vacuum pump 8 via a second pipe 15. A waste water
line 17 leads from the condensate trap 16 to a condensation tray 18
which is mounted in a manner known per se on the compressor 5 in
order to be heated by its waste heat and which collects the water
of condensation which has collected on the evaporator 7 after being
diverted from the inner area 3 through a hole in the body 1.
[0023] The exemplary embodiment in FIG. 2 differs from that in FIG.
1 in two aspects which can be achieved independently of one
another.
[0024] The first aspect is that the refrigerator comprises a second
evacuatable compartment 19 which is separated from the compartment
10 by a thin, heat-transmitting intermediate wall 20 and is
surrounded jointly with this by an insulating outer wall 21 which
separates the compartments 10, 19 from the remainder of the inner
area 3.
[0025] The pipe 9 opens at the suction intake 14 into the lower
compartment 10; a shut-off valve 22 in the intermediate wall 20
allows the two compartments 10, 19 to be separated from one another
as desired or to be connected to one another for evacuation. In
FIG. 2 each compartment 10, 18 is allocated its own flap 11;
however, they could also be closed by a common flap. The
compartment 10 can be loaded with chilled goods or it can be filled
with water which merely serves to produce latent heat of
evaporation during evacuation. The water can be brought in in the
form of a water-filled flat tray or preferably in conjunction with
a porous hydrophilic material such as cloth, fleece or foam which
provides a large surface for the evaporation of water.
[0026] The second difference lies in the attachment of the
evaporation tray 18 which is not mounted on the compressor 5 in
FIG. 2 but in a base region 23 of the refrigerator below the
heat-insulating bottom of the body 1. This base region 23 also
contains a fan 24 and a condenser 25 which is placed between the
fan 24 and evaporation tray 18 in such a manner that at the
condenser 25 heated fan air passes over the water surface of the
evaporation tray 18.
* * * * *