WO2009038427A2

WO2009038427A2 - Apparatus for supercooling

Info

Publication number: WO2009038427A2
Application number: PCT/KR2008/005620
Authority: WO
Inventors: Su-Cheong Kim; Ju-Hyun Kim
Original assignee: Lg Electronics, Inc.
Priority date: 2007-09-21
Filing date: 2008-09-22
Publication date: 2009-03-26
Also published as: WO2009038427A3; KR100872236B1

Abstract

The present invention relates to an apparatus for supercooling which supplies supercooled water phase-transited into a slush state, when a user takes water through a dispenser. An apparatus for supercooling according to the present invention includes: a cooling chamber for supplying cool air; a water tank positioned in the cooling chamber to store supercooled water; a water supply hole positioned at a lower portion of the water tank and connected to an external water supply source; a supercooled water discharge hole positioned higher than the water supply hole; and a water supply valve positioned between the external water supply source and the water supply hole.

Description

APPARATUS FOR SUPERCOOLING

Technical Field

[1] The present invention relates to an apparatus for supercooling, and more particularly, to an apparatus for supercooling which keeps water in a supercooled state in a water tank provided therein, so that a user can take supercooled water. Background Art

[2] A term "supercooling" describes a phenomenon that melt or solid does not change even after it is cooled down to a temperature lower than the phase transition temperature at equilibrium state. In general, every material has its own stable state at a given temperature, so if temperature changes gradually, atoms of the substance keep abreast with the changes of temperature while maintaining its stable state at each temperature. However, if temperature changes abruptly, there is not enough time for the atoms to get into a stable state corresponding to each temperature. What happens then is the atoms either keep the stable state at a start temperature, or partially change to a state at a predetermined end temperature then stop.

[3] For example, when water is cooled slowly, it does not freeze for some time even though the temperature is below 0 °C. However, when an object becomes a supercooled state, it is a sort of metastable state where the unstable equilibrium state breaks easily even by a very small stimulus or rrinor external disturbance, so the object easily transits to a more stable state. That is to say, if a small piece of the material is put into a supercooled liquid, or if the liquid is subject to impact on a sudden, it starts being solidified immediately and temperature of the liquid is raised to a freezing point, maintaining a stable equilibrium state at the temperature.

[4] In general, an electrostatic atmosphere is created in a refrigerator, and meats and fishes are thawed therein at a temperature below zero. Besides meats and fishes, fruits are also kept fresh in the refrigerator.

[5] Such technology uses the supercooling phenomenon. According to the supercooling phenomenon, a molten object or a solid in an equilibrium state does not go through the phase change even at temperatures below a phase transition temperature.

[6] As a relevant technology, Korean Laid-Open Patent 2000-0011081 introduced a method and equipment for treating electrostatic field and electrode used therein.

[7] FIG. 1 is a view illustrating a thawing and freshness-keeping apparatus in accordance with a prior art. A cool-keeping device 1 is formed of a heat insulation material 2 and an outer wall 5. A temperature regulator (not shown) is installed therein. A metal shelf 7 installed in the device 1 has a two-layer structure. Objects such as vegetables, meats and marine products that are to be thawed, kept fresh, or ripened are mounted on either layer. The metal shelf 7 is intentionally insulated from the bottom by an insulator 9. In addition, since a high voltage generator 3 can generate 0 to 5000 V of DC and AC voltages, the inside of the heat insulation material 2 is covered with an insulation plate 2a such as vinyl chloride. A high voltage cable 4 for outputting the voltage of the high voltage generator 3 is connected to the metal shelf 7 through the outer wall 5 and the heat insulation material 2.

[8] When a user opens a door installed at the front of the cool-keeping device 1, a safety switch 13 (not shown; refer to FKJ. 2) is off to block the output from the high voltage generator 3.

[9] FKJ. 2 is a circuit view illustrating a circuit configuration of the high voltage generator 3. 100 V AC is supplied to a primary side of a voltage adjustment transformer 15. Reference numeral 11 denotes a power lamp and 19 denotes an operation state lamp. When the door 6 is closed and the safety switch 13 is on, a relay 14 is operated. This operation state is displayed by a relay operation lamp 12. Relay contact points 14a, 14b and 14c are closed due to the operation of the relay 14, and 100 V AC is applied to the primary side of the voltage adjustment transformer 15.

[10] The applied voltage is adjusted by an adjustment knob 15a on a secondary side of the voltage adjustment transformer 15, and the adjusted voltage value is displayed on a voltmeter. The adjustment knob 15a is connected to a primary side of a boosting transformer 17 on the secondary side of the voltage adjustment transformer 15. The boosting transformer 17 boosts a voltage at a rate of 1 : 50. For example, when 60 V input voltage is applied, it is boosted to 3000 V.

[11] One end O of the secondary side output of the boosting transformer 17 is connected to the metal shelf 7 that is insulated from the cool-keeping device 1 through the high voltage cable 4, and the other end O of the output is earthed. In addition, since the outer wall 5 is earthed, even though the user touches the outer wall 5 of the cool- keeping device 1, he or she will not get an electric shock. Meanwhile, in FKJ. 1, when the metal shelf 7 is exposed in the device 1, it needs to be maintained in an insulated state, and thus needs to be spaced apart from the wall of the device 1 (the air serves to insulate). Moreover, when an object 8 protrudes from the metal shelf 7 to contact the wall of the device 1, the current flows to the ground through the wall of the device 1. Thus, by attaching the insulation plate 2a to the inner wall, drop of the applied voltage can be prevented.. Further, although the metal shelf 7 in the device 1 is not exposed but covered with vinyl chloride, the entire device 1 is under an electric field.

[12] In the prior art, an electric field or magnetic field is applied to a refrigerated stored item so that the stored item can enter a supercooled state. That is, a complex device for generating an electric field or magnetic field has to be provided to keep the stored item in the supercooled state. Unfortunately, this process takes a lot of power, and the device also mist have a safety device (e.g., an electric field or magnetic field shielding mechanism, a cut-off unit, etc.) additionally to protect a user from high electricity, especially when it is engaged in generation or cutting off the electric field or the magnetic field.

[13]

Disclosure of Invention Technical Problem

[14] An object of the present invention is to provide an apparatus for supercooling which includes a water tank for storing water in a supercooled state.

[15] Another object of the present invention is to provide an apparatus for supercooling which includes a supercooled water dispenser so that a user can take supercooled water on the outside of a door of the apparatus.

[16] A further object of the present invention is to provide an apparatus for supercooling which can supply supercooled water phase-transited into a slush state, when a user takes supercooled water through a dispenser. Technical Solution

[17] In order to achieve the above-described objects of the invention, there is provided an apparatus for supercooling, including: a cooling chamber for supplying cool air; a water tank positioned in the cooling chamber to store supercooled water; a water supply hole positioned at a lower portion of the water tank and connected to an external water supply source; a supercooled water discharge hole positioned higher than the water supply hole; and a water supply valve positioned between the external water supply source and the water supply hole.

[18] According to one aspect of the present invention, the apparatus for supercooling further includes a water intake button for controlling opening and closing of the water supply valve, wherein, when the water supply valve is opened, supercooled water is discharged to the supercooled water discharge hole.

[19] According to another aspect of the present invention, the apparatus for supercooling further includes: a water intake hole positioned outside the cooling chamber so that a user can take supercooled water; and a water intake passage connecting the supercooled water discharge hole to the water intake hole, and existing in an environment of a temperature higher than an ice crystal formation temperature.

[20] According to a further aspect of the present invention, the water intake passage includes an almost n-shaped section composed of an upward portion, a downward portion and a connection portion.

[21] According to a still further aspect of the present invention, the supercooled water discharge hole is positioned at an upper portion of the water tank.

[22] According to a still further aspect of the present invention, the cooling chamber is partitioned into a freezing chamber and a refrigerating chamber, and the water tank is positioned in the freezing chamber.

[23] There is also provided an apparatus for supercooling, including: a water tank positioned inside a freezing chamber door to store water at a temperature below zero; a water supply passage connected to a lower portion of the water tank; a water intake passage with one end connected to an upper portion of the water tank and the other end exposed to the outside of the door; and a water supply valve installed on the water supply passage.

[24] According to one aspect of the present invention, the water intake passage is positioned over different temperature regions.

[25] According to another aspect of the present invention, the water intake passage is formed in a bent shape so that water can remain therein to a predetermined position.

[26] According to a further aspect of the present invention, the position of the water intake passage where water remains has an environment of a temperature higher than a maximum ice crystal formation temperature zone.

[27] In addition, there is provided an apparatus for supercooling, including: a cooling chamber for supplying cool air; a water tank positioned in the cooling chamber to store supercooled water; a water supply hole positioned at a lower portion of the water tank and connected to an external water supply source; a supercooled water discharge hole positioned higher than the water supply hole; a water supply valve positioned between the external water supply source and the water supply hole; and a water intake passage with one end connected to an upper portion of the water tank and the other end exposed to the outside of the door.

[28] According to one aspect of the present invention, some portion of the water intake passage exists in an environment of a temperature higher than a maximm ice crystal formation temperature zone of water.

[29] According to another aspect of the present invention, water remains in the water intake passage, and the interface of the remaining water is positioned in some portion of the water intake passage existing in the environment of the temperature higher than the maximum ice crystal formation temperature zone of water.

[30] According to a further aspect of the present invention, the water intake passage includes a trap structure so that water can remain in the trap.

[31] According to a still further aspect of the present invention, some portion of the trap structure exists at a temperature higher than a maximum ice crystal formation temperature zone of water, and the interface of the remaining water is exposed to the maximum ice crystal formation temperature zone thereof. Advantageous Effects

[32] The apparatus for supercooling in accordance with the present invention includes the water tank for storing water in the supercooled state, so that the user can take supercooled water and use it in the slush state.

[33] The apparatus for supercooling in accordance with the present invention enables the surface of water generating ice crystals to exist in the temperature region above zero, thereby preventing water from being frozen.

[34] In accordance with the present invention, one end of the water intake passage of supercooled water, i.e., the water intake hole, exists outside the apparatus for supercooling, so that the user can easily take supercooled water from the apparatus for supercooling.

[35] The apparatus for supercooling in accordance with the present invention positions the water intake passage over the temperature regions above and below zero, thereby preventing supercooled water remaining in the water intake passage from being frozen. Brief Description of the Drawings

[36] FIG. 1 is a view illustrating a thawing and freshness keeping apparatus in accordance with a prior art.

[37] FIG. 2 is a circuit view illustrating a circuit configuration of a high voltage generator.

[38] FIG. 3 is a view illustrating a process of forming freezing nuclei in liquid being cooled.

[39] FIG. 4 is a view illustrating a process of preventing the formation of freezing nuclei, which is applied to an apparatus for supercooling in accordance with the present invention. [40] FIG. 5 is a graph showing a supercooled state of water in result of the process of

HG. 4.

[41] FIG. 6 is a view illustrating an apparatus for supercooling in accordance with an embodiment of the present invention.

[42] FIG. 7 is a view illustrating one example of a supercooled water dispenser provided in the apparatus for supercooling in accordance with the embodiment of the present invention. Mode for the Invention

[43] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[44] FIG. 3 is a view illustrating a process of forming freezing nuclei in liquid being cooled. As is shown in FKJ. 3, a container C containing a liquid L is refrigerated in a cooling space S.

[45] It is assumed that a cooling temperature inside the cooling space S falls from a normal temperature below 0⁰C (a phase transition temperature of water) or below a phase transition temperature of the liquid L. While being cooled, the water or liquid L is intended to stay in a supercooled state even below a maximum formation temperature zone (-1 to -5 ⁰C) of water forrring a maxirram amount of ice crystals, or even below a maximm ice crystal formation temperature zone of the liquid L.

[46] Meanwhile, the liquid L evaporates during the cooling process, so that vapor Wl flows into a gas (or space) Lg in the container C. In a case where the container C is closed by lid Ck, the gas Lg may be over-saturated die to the evaporated vapor Wl. In this embodiment, the lid Ck is included in the container C as an option. The container C with the lid Ck can prevent the cool air from being introάiced directly from the cooling space S, or prevent the temperature of the surface Ls of the liquid L or the gas Lg on the surface Ls of the liquid L from being lowered by the cool air.

[47] When the cooling temperature reaches or exceeds the maximum ice crystal formation temperature zone of the liquid L, the liquid L forms ice crystal cores Fl in the gas Lg or freezing nuclei F2 on the inner wall of the container C. In addition, condensation may occur in a contact portion of the surface Ls of the liquid L and the inner wall of the container C (almost the cooling temperature inside the cooling space S), so that the condensed liquid L forms freezing nuclei F3.

[48] For example, when the freezing nuclei Fl in the gas Lg pass through the surface Ls of the liquid L and infiltrate into the liquid L, the liquid L is released from the supercooled state and freezes. [49] For another example, when the freezing nuclei F3 are brought into contact with the surface Ls of the liquid L, the liquid L is released from the supercooled state and freezes.

[50] As described above, according to the process of fornϊng the freezing nuclei Fl to F3, when the liquid L is kept below the maximum ice crystal formation temperature zone thereof, since the vapor Wl evaporated from the liquid L and positioned on the surface Ls of the liquid L and the inner wall of the container C adjacent to the surface Ls of the liquid L freezes, the liquid L is released from the supercooled state.

[51 ] FKJ. 4 is a view illustrating a process of preventing the formation of freezing nuclei, which is applied to an apparatus for supercooling in accordance with the present invention.

[52] In FIG. 4, to prevent the vapor Wl in the gas Lg from being frozen, i.e., to continuously maintain the vapor Wl, a temperature of the gas Lg or the surface Ls of the liquid L is set up higher than the maximum ice crystal formation temperature zone of the liquid L, more preferably, the phase transition temperature of the liquid L. Moreover, in order to prevent the surface Ls of the liquid L brought into contact with the inner wall of the container C from being frozen, the temperature of the surface Ls of the liquid L is set up higher than the maximum ice crystal formation temperature zone of the liquid L, more preferably, the phase transition temperature of the liquid L.

[53] Accordingly, the liquid L in the container C stays in the supercooled state at temperatures below the phase transition temperature or the maximum ice crystal formation temperature zone thereof.

[54] FIG. 5 is a graph showing a supercooled state of water under the process in FIG. 4.

Provided that the liquid L is water, temperatures were measured by applying the principle of FKJ. 4 thereto.

[55] Referring to FKJ. 5, 1 indicates a cooling temperature curve for the cooling space S,

II indicates a temperature curve for the gas (air) Lg above or on the surface of water in the container C, and III indicates a temperature curve for the outer surface of the container C, which is substantially identical to a temperature of water in the container C.

[56] Still referring to FKJ. 5, in a case where the cooling temperature maintains at about -

13 to -14 ⁰C (see I), when the temperature of the gas Lg above or on the surface of water in the container C maintains at about 4 to 6 ⁰C higher than the maximum ice crystal formation temperature zone of water, although the temperature of water in the container C maintains at about -11 ⁰C lower than the maximum ice crystal formation temperature zone of water, water is stably maintained in a supercooled state which is a liquid state over a long period of time.

[57] FIG. 6 is a view illustrating an apparatus for supercooling according to an embodiment of the present invention. An apparatus 1000 for supercooling includes a casing 1200 composing the outer appearance. A cooling chamber 1100 maintained at a temperature below zero is defined in the casing 1200. The casing 1200 includes a main body 1210 and a door 1220. The casing 1200 is provided with a layer foamed with a heat insulation material so as to insulate the cooling chamber 1100 from the outside. A water tank 1300 for storing supercooled water is provided in the door 1220. The water tank 1300 is exposed to cool air of the cooling chamber 1100. Therefore, water stored in the water tank 1300 is stored at the temperature below zero.

[58] In addition, a water supply passage 1400 for introducing water from an external water supply source to the water tank 1300 is connected to a lower portion of the water tank 1300. A valve 1410 for controlling inflow of water is installed on the water supply passage 1400. A water intake passage 1330 is connected to an upper portion of the water tank 1300 so that a user can take supercooled water stored in the water tank 1300 on the outside of the door 1220. The water intake passage 1330 is connected to a water intake hole 1350 via the door 1220. The water supply passage 1400 is connected to the lower portion of the water tank 1300, the water intake passage 1330 is connected to the upper portion thereof, and the water tank 1300 is filled with water without an air layer. Meanwhile, water is discharged from the water tank 1300 without generating the air layer. That is, when the valve 1410 is opened, water flows into the water tank 1300 to push water in the water tank 1300, so that water is discharged through the water intake hole 1350 positioned outside the door 1220 along the water intake passage 1330. As the air layer is not formed in the water tank 1300, ice crystals are not generated. Therefore, water in the water tank 1300 can be stored in the supercooled state.

[59] A lever 1360 is installed around the water intake hole 1350 so that the user can control the discharge of supercooled water. The lever 1360 and the valve 1410 are designed to mechanically or electronically interwork with each other. When the user pushes the lever 1360 to take supercooled water, the valve 1410 is opened to push water in the water tank 1300. When the valve 1410 and the lever 1360 are distant from each other, they cannot be easily designed to mechanically interwork with each other. Accordingly, preferably, the valve 1410 and the lever 1360 are designed to be located closely to each other, or to electronically interwork with each other under the control of a control unit (not shown).

[60] FIG. 7 is a view illustrating one example of a supercooled water dispenser provided in the apparatus for supercooling according to the embodiment of the present invention. As described above, a water tank 1300 is exposed to cool air of the supercooling chamber 1100 (refer to FKJ. 6). A water supply passage 1400 is connected to the water tank 1300, and provided with a valve 1410 for controlling inflow of water. One end of the water supply passage 1400 is connected to a water supply source, and the other end thereof is connected to the water tank 1300. Preferably, the other end of the water supply passage 1400 is connected to a lower portion of the water tank 1300, or inserted into the water tank 1300 and positioned in the bottom of the water tank 1300.

[61] In addition, a water intake passage 1330 for externally discharging supercooled water is connected to an upper portion of the water tank 1300. The other end of the water intake passage 1330 is connected to a water intake hole 1350 positioned outside the apparatus 1000 for supercooling. A member for allowing the user to select whether to take supercooled water is installed around the water intake hole 1350. Generally, the member is implemented with a lever 1360. When the user presses the lever 1360 with a cup, the water intake passage 1330 is opened to discharge supercooled water to the cup. The supercooled water is converted into a slush state due to an elevation difference. Preferably, the water intake passage 1330 and the water supply passage 1400 are opened at the same time. That is, so as to remove an air layer serving to generate ice crystals in the water tank 1300, water is supplied along the water supply passage 1400, and supercooled water is pushed by the supplied water and discharged along the water intake passage 1330.

[62] The water intake passage 1330 is connected to the outside of the apparatus 1000 for supercooling via the heat insulation material of the door 1220. The outside of the door 1220, i.e., the outside of the apparatus 1000 for supercooling has a normal temperature, and the supercooling chamber 1100 accommodating the water tank 1300 has a temperature below zero. Accordingly, the heat insulation material has a linear temperature distribution so that the outer surface side of the door 1220 can have the normal temperature and the inner surface side thereof can have the temperature below zero. As a result, the water intake passage 1330 is positioned over a temperature region ranging from the temperature below zero to the normal temperature. Here, the shape and length of the water intake passage 1330 are determined so that the surface of water remaining in the water intake passage 1330 can exist in a temperature region higher than a maximm ice crystal formation temperature zone. This configiration serves to prevent water remaining in the water intake passage 1330 from being frozen. Since the water intake passage 1330 is formed in a bent shape at a certain relative height of the water tank 1300, water can be always left in the bent portion. Moreover, the bent portion is positioned at a predeternined depth from the outer surface of the door 1220, so that a temperature around the bent portion can be set up. Accordingly, water remaining in the water intake passage 1330 can exist within a predeternined temperature range, and the surface of the remaining water can exist at a temperature higher than the maximun ice crystal formation temperature zone, more preferably, at a temperature above zero. Consequently, since ice crystals are not formed on the surface of water remaining in the water intake passage 1330, water remaining in the water intake passage 1330 can be prevented from being frozen. Further, since water in the water intake passage 1330 is not frozen, water stored in the water tank 1300 is not frozen but stored in the supercooled state. The apparatus 1000 for supercooling according to the present invention stores water in the supercooled state in the water tank 1300 and the water intake passage 1330, so that the user can take supercooled water anytime and use it in the slush state. [63]

Claims

[1] An apparatus for supercooling, comprising: a cooling chamber for supplying cool air; a water tank positioned in the cooling chamber to store supercooled water; a water supply hole positioned at a lower portion of the water tank and connected to an external water supply source; a supercooled water discharge hole positioned higher than the water supply hole; and a water supply valve positioned between the external water supply source and the water supply hole. [2] The apparatus for supercooling of claim 1, further comprising a water intake button for controlling opening and closing of the water supply valve, wherein, when the water supply valve is opened, supercooled water is discharged to the supercooled water discharge hole. [3] The apparatus for supercooling of claim 1, further comprising: a water intake hole positioned outside the cooling chamber so that a user can take supercooled water; and a water intake passage connecting the supercooled water discharge hole to the water intake hole, and existing in an environment of a temperature higher than an ice crystal formation temperature. [4] The apparatus for supercooling of claim 3, wherein the water intake passage comprises an almost n-shaped section composed of an upward portion, a downward portion and a connection portion. [5] The apparatus for supercooling of claim 1, wherein the supercooled water discharge hole is positioned at an upper portion of the water tank. [6] The apparatus for supercooling of claim 1, wherein the cooling chamber is partitioned into a freezing chamber and a refrigerating chamber, and the water tank is positioned in the freezing chamber. [7] An apparatus for supercooling, comprising: a water tank positioned inside a freezing chamber door to store water at a temperature below zero; a water supply passage connected to a lower portion of the water tank; a water intake passage with one end connected to an upper portion of the water tank and the other end exposed to the outside of the door; and a water supply valve installed on the water supply passage. [8] The apparatus for supercooling of claim 7, wherein the water intake passage is positioned over different temperature regions. [9] The apparatus for supercooling of claim 7, wherein the water intake passage is formed in a bent shape so that water can remain therein to a predetermined position. [10] The apparatus for supercooling of claim 9, wherein the position of the water intake passage where water remains has an environment of a temperature higher than a maximm ice crystal formation temperature zone. [11] An apparatus for supercooling, comprising: a cooling chamber for supplying cool air; a water tank positioned in the cooling chamber to store supercooled water; a water supply hole positioned at a lower portion of the water tank and connected to an external water supply source; a supercooled water discharge hole positioned higher than the water supply hole; a water supply valve positioned between the external water supply source and the water supply hole; and a water intake passage with one end connected to an upper portion of the water tank and the other end exposed to the outside of the door. [12] The apparatus for supercooling of claim 11, wherein some portion of the water intake passage exists in an environment of a temperature higher than a maximun ice crystal formation temperature zone of water. [13] The apparatus for supercooling of claim 12, wherein water remains in the water intake passage, and the interface of the remaining water is positioned in some portion of the water intake passage existing in the environment of the temperature higher than the maximun ice crystal formation temperature zone of water. [14] The apparatus for supercooling of claim 11, wherein the water intake passage comprises a trap structure so that water can remain in the trap. [15] The apparatus for supercooling of claim 14, wherein some portion of the trap structure exists at a temperature higher than a maximum ice crystal formation temperature zone of water, and the interface of the remaining water is exposed to the maximun ice crystal formation temperature zone thereof.