WO2022158931A2

WO2022158931A2 - Laundry treating apparatus

Info

Publication number: WO2022158931A2
Application number: PCT/KR2022/001227
Authority: WO
Inventors: Junghan Kim; Jangseok Lee
Original assignee: Lg Electronics Inc.
Priority date: 2021-01-25
Filing date: 2022-01-24
Publication date: 2022-07-28
Also published as: WO2022158931A3; KR20220107555A; KR102472994B1

Abstract

The present disclosure relates to a laundry treating apparatus including a pressure vessel, a storage tank storing carbon dioxide therein, and supplying carbon dioxide to the pressure vessel, and a distiller for vaporizing liquid carbon dioxide of carbon dioxide discharged from the pressure vessel to remove foreign substances therefrom, and then, liquefying vaporized carbon dioxide and supplying liquefied carbon dioxide to the storage tank, wherein the distiller includes a distillation tank located below the pressure vessel and storing carbon dioxide discharged from the pressure vessel to remove foreign substances dissolved in carbon dioxide discharged from the pressure vessel, a circulation flow path located outside the distillation tank to circulate liquid carbon dioxide stored in the distillation tank, and an external heat exchanger positioned on the circulation flow path to heat liquid carbon dioxide passing through the circulation flow path using external heat.

Description

LAUNDRY TREATING APPARATUS

The present disclosure relates to a laundry treating apparatus and a method for controlling the same. More particularly, the present disclosure relates to a laundry treating apparatus that performs laundry treatment such as washing or the like using carbon dioxide.

A laundry treating apparatus may perform washing and drying laundry at home or in other places, and can remove wrinkles on the laundry. For example, the laundry treating apparatus can include a washing machine that washes the laundry, a dryer that dries the laundry, a washing machine/dryer that has both a washing function and a drying function, a laundry manager that refreshes the laundry, a steamer that removes the wrinkles from the laundry, and the like.

The laundry treating apparatus may treat the laundry using water. In some cases, after a washing cycle has been completed, water can remain on the laundry even after a dehydration process. In order to dry the wet laundry, the laundry can be dried naturally or by hot air supplied through a separate drying cycle with additional time for the drying cycle.

The laundry treating apparatus may use water and detergent to foreign substances adhered to or adsorbed on the laundry. In some cases, instead of water, an organic solvent such as perchlorethylene (PCE) can be used to remove lipophilic foreign substances. Because the organic solvent is volatile, the drying cycle can be shorter than the drying cycle using the water. In some cases, in removing the lipophilic foreign substances, there is a limitation in removing water-soluble foreign substances. In some cases, after the drying cycle using the hot air is performed, a smell of a remaining volatile organic compound may give an unpleasant feeling and stay for a long time. In some examples, perchlorethylene is harmful to an environment, and it has been designated as a carcinogen by the US Environmental Protection Agency.

Carbon dioxide (CO2) may be used as a new cleaning solvent to prevent or reduce such carcinogen and environmental pollution. Carbon dioxide is a colorless and odorless gas at an ambient pressure and at a room temperature, and carbon dioxide may evaporate when a washing process at a high pressure is completed and the pressure is lowered to the atmospheric pressure, which may obviate the need for a separate drying cycle. In some examples, as carbon dioxide is one of components of general atmosphere, carbon dioxide may not pollute the environment. In some examples, when a surfactant for carbon dioxide is used, it may be possible to remove hydrophilic foreign substances.

In addition, when a distiller or a distillation tank is utilized, carbon dioxide contaminated after the washing may be reused by removing only the foreign substances from the contaminated carbon dioxide and then distilling the contaminated carbon dioxide into clean carbon dioxide.

U.S. Patent No. US6860123B1 discloses a cycle of distilling and reusing liquid carbon dioxide contaminated after the washing using the distiller. That is, after the washing, the liquid carbon dioxide in a washing tub is discharged to the distillation tank, and then is regenerated using heat in a distillation tub to be recycled. To this end, a heat exchanger (or a regenerator) for heat exchange between gaseous carbon dioxide and the liquid carbon dioxide is installed inside the distillation tank. The gaseous carbon dioxide separated from the foreign substances is compressed through a compressor to become a high-temperature, high-pressure gas, and enters the heat exchanger. In this connection, through the heat exchange with the liquid carbon dioxide inside a liquid distillation tank, the liquid carbon dioxide evaporates and the gaseous carbon dioxide becomes liquefied. In this connection, the liquefied gas carbon dioxide may be transferred back to a storage tank and reused.

However, during the heat exchange process, the liquid carbon dioxide inside the distillation tank is vaporized, so that a liquid level of the liquid carbon dioxide gradually decreases. In this case, as a suction density of the gaseous carbon dioxide in the compressor is lowered, a flow rate decreases during the heat exchange (the regeneration), and, as an external heat resistance of the heat exchanger increases, a heat exchange performance (or a regeneration efficiency) is deteriorated. This also has a problem in that a lot of time is required for the regeneration during operation.

In addition, when a capacity of the carbon dioxide storage tank is reduced to reduce a size of the laundry treating apparatus, the distilled carbon dioxide must be reused in the washing process, so that there is a problem in that a washing time increases as much as a time of a great amount required in the distillation process.

First, the present disclosure aims to solve a problem that an internal pressure of a distillation tank is lowered when gaseous carbon dioxide inside the distillation tank is extracted with a compressor in a distillation process.

Second, the present disclosure aims to prevent a problem that, as liquid carbon dioxide inside the distillation tank gradually evaporates during the distillation process, a liquid level of the liquid carbon dioxide is lowered, and accordingly, a compressor suction density is lowered to decrease a flow rate of the carbon dioxide passing through an internal heat exchanger disposed inside the distillation tank to deteriorate a heat exchange performance.

Third, the present disclosure aims to reduce a time required for distillation.

Fourth, the present disclosure aims to improve an energy efficiency using a heat pump used to lower a pressure of a storage tank as an external heat source for heating the liquid carbon dioxide.

To solve the above problem, an external heat exchanger may be included on the outside of a distillation tank. This is to exchange heat with liquid carbon dioxide discharged from the distillation tank using an external heat source, heat the liquid carbon dioxide, and then supply the liquid carbon dioxide to the distillation tank again.

To this end, a blowing fan that sucks outside air and introduces air to a region around the external heat exchanger through which the liquid carbon dioxide flows to transfer heat to the liquid carbon dioxide by a temperature difference between the air and the liquid carbon dioxide may be further included.

That is, in a distillation process or a distillation regeneration process, evaporation heat is supplied to the liquid carbon dioxide through the external heat exchanger.

To this end, a laundry treating apparatus may include a pressure vessel for maintaining carbon dioxide accommodated therein at a pressure higher than an atmospheric pressure, a storage tank located above the pressure vessel, storing carbon dioxide therein, and supplying carbon dioxide to the pressure vessel, and a distiller for vaporizing liquid carbon dioxide of carbon dioxide discharged from the pressure vessel to remove foreign substances therefrom, and then, liquefying vaporized carbon dioxide and supplying liquefied carbon dioxide to the storage tank, and the distiller may include a distillation tank located below the pressure vessel and storing carbon dioxide discharged from the pressure vessel to remove foreign substances dissolved in carbon dioxide discharged from the pressure vessel, a circulation flow path located outside the distillation tank to circulate liquid carbon dioxide stored in the distillation tank, and an external heat exchanger positioned on the circulation flow path to heat liquid carbon dioxide passing through the circulation flow path using external heat.

One end of the circulation flow path may be connected to the distillation tank at a lower portion of the distillation tank such that liquid carbon dioxide stored in the distillation tank flows into the circulation flow path.

The distiller may further include a circulation pump located on the circulation flow path between the distillation tank and the external heat exchanger and flowing liquid carbon dioxide stored in the distillation tank toward the external heat exchanger.

The circulation flow path may further include a first circulation pipe for connecting the distillation tank and the external heat exchanger to each other to flow liquid carbon dioxide stored in the distillation tank to the external heat exchanger, and a second circulation pipe for flowing carbon dioxide that has passed through the external heat exchanger to the distillation tank.

The second circulation pipe may be connected to the distillation tank at an upper portion of the distillation tank.

The laundry treating apparatus may further include a discharge pipe for connecting the pressure vessel and the distillation tank to each other to discharge carbon dioxide from the pressure vessel to the distillation tank, and the second circulation pipe may be connected to the discharge pipe to flow carbon dioxide that has passed through the external heat exchanger to the distillation tank through the discharge pipe.

The discharge pipe may be connected to the distillation tank at an upper portion of the distillation tank.

The distiller may further include a distillation compressor located outside the distillation tank, sucking gaseous carbon dioxide from the distillation tank, and compressing sucked gaseous carbon dioxide, an internal heat exchanger located inside the distillation tank and connected to the distillation compressor to perform heat exchange of compressed gaseous carbon dioxide with liquid carbon dioxide stored inside the distillation tank, and a storage pipe for connecting the internal heat exchanger and the storage tank to each other to flow carbon dioxide cooled while passing through the internal heat exchanger to the storage tank.

The distiller may further include a suction pipe for connecting the distillation tank and the distillation compressor to each other to flow gaseous carbon dioxide from the distillation tank to the distillation compressor, and a discharge pipe for connecting the distillation compressor and the internal heat exchanger to each other to flow compressed gaseous carbon dioxide to the internal heat exchanger.

The internal heat exchanger may be located at a lower portion inside the distillation tank.

The suction pipe may be connected to the distillation tank at an upper portion of the distillation tank.

The laundry treating apparatus may further include a blowing fan for sucking air and supplying air, and heat may be supplied to liquid carbon dioxide passing through the external heat exchanger using heat of air sucked by the blowing fan.

The laundry treating apparatus may further include a cabinet including the pressure vessel, the storage tank, and the distiller therein, and the storage tank and the distillation tank may be disposed closer to the other side surface than to one side surface of left and right side surfaces of the cabinet.

The laundry treating apparatus may further include a first heat exchanger for heat exchange with the storage tank to maintain a pressure of the storage tank at a pressure equal to or lower than a preset reference pressure, a second heat exchanger for supplying heat to liquid carbon dioxide passing through the external heat exchanger through heat exchange with the external heat exchanger, and a refrigerant compressor for compressing a refrigerant circulating through the first heat exchanger and the second heat exchanger.

The laundry treating apparatus may further include a circulation fan for cooling outside air through the first heat exchanger and then flowing outside air to the storage tank to cool the storage tank using outside air cooled by the first heat exchanger.

First, the present disclosure may reduce the problem that the internal pressure of the distillation tank is lowered when the gaseous carbon dioxide inside the distillation tank is extracted with the compressor in the distillation process.

Second, the present disclosure may prevent the problem that, as the liquid carbon dioxide inside the distillation tank gradually evaporates during the distillation process, the liquid level of the liquid carbon dioxide is lowered, and accordingly, the compressor suction density is lowered to decrease the flow rate of the carbon dioxide passing through the internal heat exchanger disposed inside the distillation tank to deteriorate the heat exchange performance.

Third, the present disclosure may reduce the time required for the distillation.

Fourth, the present disclosure may improve the energy efficiency using a heat dissipated from a condenser of the heat pump used to lower the pressure of the storage tank as the external heat source for heating the liquid carbon dioxide.

(a) and (b) in FIG. 1 show an example of a laundry treating apparatus described in the present disclosure.

FIG. 2 shows an example of a drum and a driver disposed inside a pressure vessel.

FIG. 3 is a rear view of a partition wall and a driver after separating a second housing from a pressure vessel.

(a) and (b) in FIG. 4 are a front view and a side view of a partition wall, respectively.

FIG. 5 schematically shows components of a laundry treating apparatus using carbon dioxide as a washing solvent.

(a) in FIG. 6 shows an example of a pressurization operation for reaching pressure equilibrium using gaseous carbon dioxide stored in a storage tank during a washing cycle of a laundry treating apparatus described in the present disclosure. (b) in FIG. 6 shows another example of the pressurization operation during the washing cycle of the laundry treating apparatus of the present disclosure.

(a) in FIG. 7 shows an operation of supplying liquid carbon dioxide to a pressure vessel using a vertical level difference between a storage tank and a pressure vessel after a pressurization operation and a replenishment operation are completed. (b) in FIG. 7 is an operation of recovering liquid carbon dioxide inside the pressure vessel by supplying carbon dioxide to the pressure vessel using the vertical level difference between the storage tank and the pressure vessel before proceeding with a rinsing process after washing is complete.

(a) in FIG. 8 shows a distillation operation for distilling liquid carbon dioxide discharged to a distillation tank after a washing operation or a rinsing operation. (b) in FIG. 8 shows a recovery operation of recovering gaseous carbon dioxide remaining in a pressure vessel and removing residual gas before completing a washing cycle after the rinsing operation.

FIG. 9 shows a distillation process using an external heat exchanger disposed in a laundry treating apparatus.

FIG. 10 shows an example of using a heat pump as an external heat source for external heat exchange.

Hereinafter, a preferred embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. In one example, a configuration of a device or a method for controlling the same to be described below is only for describing an embodiment of the present disclosure, not for limiting the scope of the present disclosure, and reference numerals used the same throughout the specification refer to the same components.

Specific terms used in this specification are only for convenience of description and are not used as a limitation of the illustrated embodiment.

For example, expressions indicating that things are in the same state, such as "same", "equal", "homogeneous", and the like, not only indicate strictly the same state, but also indicate a state in which a tolerance or a difference in a degree to which the same function is obtained exists.

For example, expressions indicating a relative or absolute arrangement such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “central”, “concentric”, “coaxial”, or the like not only strictly indicate such arrangement, but also indicate a state in which a relative displacement is achieved with a tolerance, or an angle or a distance that achieves the same function.

In order to describe the present disclosure, the description below will be achieved on the basis of a spatial orthogonal coordinate system with an X-axis, a Y-axis, and a Z-axis orthogonal to each other. Each axial direction (an X-axis direction, a Y-axis direction, or a Z-axis direction) means both directions in which each axis extends. Adding a '+' sign in front of each axial direction (a +X-axis direction, a +Y-axis direction, or a +Z-axis direction) means a positive direction, which is one of the two directions in which each axis extends. Adding a '-' sign in front of each axial direction (a -X-axis direction, a -Y-axis direction, or a -Z-axis direction) means a negative direction, which is the other of the two directions in which each axis extends.

Expressions referring to directions such as “front (+Y)/rear (-Y)/left (+X)/right (-X)/up (+Z)/down (-Z)” to be mentioned below are defined based on a XYZ coordinate axis. However, this is to describe the present disclosure such that the present disclosure may be clearly understood. In one example, each direction may be defined differently depending on the standard.

The use of terms such as 'first, second, third' in front of the components to be mentioned below is only to avoid confusion of the components referred to, and is independent of the order, importance, or master-slave relationship between the components. For example, an invention including only the second component without the first component may also be implemented.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

Hereinafter, the present disclosure is described on the premise that carbon dioxide is used as a washing solvent, but other washing solvents other than the carbon dioxide may be used.

(a) and (b) in FIG. 1 show a laundry treating apparatus 1000 as an example of the present disclosure. Referring to (a) in FIG. 1, the laundry treating apparatus 1000 includes a pressure vessel 200 for maintaining the carbon dioxide contained therein at a pressure higher than an atmospheric pressure, a storage tank 150 that is located above the pressure vessel 200 and stores the carbon dioxide and supplies the carbon dioxide to the pressure vessel 200, and a distiller 400 for vaporizing liquid carbon dioxide of the carbon dioxide discharged from the pressure vessel 200 to remove foreign substances therefrom, and then, liquefying the vaporized carbon dioxide and supplying the liquid carbon dioxide to the storage tank 150.

The storage tank 150 being located above the pressure vessel 200 may mean that, when viewed from the front, a vertical height from a bottom surface to a center of a circular cross-section of the storage tank 150 having a cylindrical shape is greater than a vertical height to a center of a circular cross-section of the pressure vessel 200 having a cylindrical shape. This may be interpreted similarly to a distillation tank of the distiller 400, so that a distillation tank 401 may be located below the pressure vessel 200.

That is, a vertical level at which the storage tank 150 is installed may be higher than that of the pressure vessel 200, and a vertical level at which the distillation tank 401 is installed may be lower than that of the pressure vessel 200.

In addition, the laundry treating apparatus 1000 may include a cabinet 100 forming an appearance of the laundry treating apparatus 1000. The pressure vessel 200 may include a drum 300 rotatably disposed inside the pressure vessel 200 and accommodating laundry therein, and a driver 500 for rotating the drum 300.

In addition, the laundry treating apparatus 1000 may further include a frame 110 disposed inside the cabinet 100 for supporting the cabinet and supporting the pressure vessel, the storage tank 150, and the distiller 400.

The laundry treating apparatus 1000 may perform a washing cycle of, after supplying the carbon dioxide to the pressure vessel 200 from the storage tank 150 in response to an input of a user, removing the foreign substances from the laundry using friction between the laundry accommodated in the drum 300 and the liquid carbon dioxide by rotating the drum 300.

The washing cycle refers to a series of operations performed by the laundry treating apparatus 1000 when the user selects a course for washing of the laundry. The washing cycle may include a pressurization operation and a supply operation of supplying the carbon dioxide to the pressure vessel 200 from the storage tank 150, a washing operation of removing the foreign substances from the laundry using the friction between the liquid carbon dioxide and the laundry by rotating the drum 300 at a preset first rotation speed, and a rinsing operation of removing the foreign substances from the laundry using the friction between the liquid carbon dioxide and the laundry by rotating the drum 300 at a preset second rotation speed.

The rinsing operation may be repeated twice. Preferably, inside the pressure vessel (or washing chamber) 200, under conditions of approximately 45 to 51 bar and 10 to 15 ℃, the washing operation may be performed for 10 to 15 minutes and the rinsing operation may be performed for 3 to 4 minutes.

After the washing operation and the rinsing operation are completed, a distillation operation may be included. The distillation refers to heating a specific liquid mixed with the foreign substances (or pollutants), then vaporizing (or evaporating) only the specific liquid, and then cooling the specific liquid again to separate only a specific pure liquid. In this specification, the distillation refers to an operation of vaporizing the liquid carbon dioxide mixed with the foreign substances removed from the laundry and then cooling the vaporized carbon dioxide to separate only pure liquid carbon dioxide. The separated liquid carbon dioxide may be reused in a next operation after being supplied to the storage tank again.

The cabinet 100 may include a cabinet bottom surface (not shown) that forms a bottom surface of the laundry treating apparatus 1000, a top panel (not shown) that forms a top surface of the cabinet 100, a front panel 103 that forms a front surface of the cabinet 100 and connects the cabinet bottom surface and the top panel to each other, side panels (not shown) that form both side surfaces of the cabinet 100 and connect the cabinet bottom surface and the top panel to each other, and a rear panel (not shown) that forms a rear face of the cabinet.

The front panel 103 may have a cabinet inlet 1031 defined therein through which the laundry may be put into the drum 300 or the laundry accommodated in the drum 300 may be withdrawn to the outside of the cabinet 100. In addition, the laundry treating apparatus 1000 may include a door 130 pivotably disposed on the front panel 103 to open and close the cabinet inlet 1031.

The pressure vessel 200 may be located inside the cabinet 100 to accommodate the carbon dioxide therein. The pressure vessel 200 may include a vessel inlet 219 defined therein capable of being in communication with the cabinet inlet. When the door 130 is closed, not only the cabinet inlet 1031, but also the vessel inlet 219 is closed, so that the pressure vessel 200 may be a pressure vessel or a pressure-resistant vessel capable of accommodating high-pressure carbon dioxide therein.

For example, the carbon dioxide supplied to the pressure vessel 200 may maintain a predetermined pressure to exist as the liquid carbon dioxide. Preferably, the pressure may be a single pressure set in a pressure range from 45 bar to 51 bar.

The drum 300 may be rotatably disposed inside the pressure vessel 200. Specifically, the drum 300 may be rotatably disposed in an inner space of a first housing 211 (see FIG. 2), that is, in a first chamber 210. The drum 300 may include a plurality of side through-holes (not shown) defined in an inner circumferential surface of the drum 300 to allow fluid communication between the pressure vessel 200 and the drum 300. That is, the drum 300 may include a drum body 301 for accommodating the laundry therein, and the plurality of side through-holes (not shown) penetrating a side surface of the drum body.

Through the plurality of side through-holes, the carbon dioxide supplied to the pressure vessel 200, specifically to the first chamber 210 (see FIG. 2) may be introduced into an accommodation space, which is a space in which the laundry is accommodated inside the drum body, or may come out of the accommodation space into a space between the first chamber 210 (see FIG. 7) and the drum 300.

The drum 300 may have a cylindrical shape. Alternatively, the drum body 301 forming an appearance of the drum 300 may have a cylindrical shape.

Therefore, the pressure vessel may perform a role of the washing chamber in which the washing operation and the rinsing operation occur using the drum 300 disposed therein.

Referring to (a) and (b) in FIG. 1, the storage tank 150, the pressure vessel 200, and the distiller 400 may be located in an order of the vertical level in a height direction with respect to the bottom surface of the cabinet. This is to flow the liquid carbon dioxide by gravity even under the same pressure condition. That is, when the storage tank 150 and the pressure vessel 200 communicate with each other even when pressures thereof are the same, the gravity may flow the liquid carbon dioxide from the storage tank 150 to the pressure vessel 200. Similarly, even when pressures of the pressure vessel 200 and the distillation tank 401 of the distiller 400 are the same, the liquid carbon dioxide may be discharged from the pressure vessel 200 to the distillation tank 401 by the gravity based on a vertical level difference.

In addition, considering weights of the storage tank 150, the pressure vessel 200, and the distillation tank 401, and the size of the laundry treating apparatus, it may be preferable for the storage tank 150, the pressure vessel 200, and the distillation tank 401 to be disposed diagonally with respect to the height direction rather than disposed vertically in a straight line in the height direction in terms of weight distribution or miniaturization of the laundry treating apparatus.

Alternatively, as shown in (a) in FIG. 1, the distillation tank 401 and the storage tank 150 may be disposed closer to the other side surface than to one side surface of the cabinet 100.

Referring to (a) and (b) in FIG. 1, although it is shown that the storage tank 150 and the distillation tank 401 among the storage tank 150, the pressure vessel 200, and the distillation tank 401 are located closer to a right side of the cabinet than to a left side of the cabinet when viewed from the front, the storage tank 150 and the distillation tank 401 may be located on a side opposite thereto.

In an empty space remaining after the storage tank 150, the pressure vessel 200, and the distillation tank 401 are disposed, various compressors, an oil separator 295, a controller 900, a heat dissipation fan 299, and various connection pipes may be located.

Referring to (b) in FIG. 1, the controller 900 may be located at a rear portion of the cabinet. This is for easy access to the controller 900. However, this is merely an embodiment. The controller 900 may be located on the side surface or the front surface of the cabinet. In FIG. 1, the controller 900 is formed in a shape of a box. A control device such as a programmable logic controller (PLC) may be disposed in the box. Alternatively, the controller 900 may be formed as a PCB including a microcomputer. FIG. 1 shows a state in which the box-like shape is pivotably disposed on the frame 110.

The controller may control the flow of the carbon dioxide by controlling opening and closing of each pipe through various flow rate control valves. In addition, the driver may be controlled to rotate the drum. In addition, the controller may receive the user input and perform the course or a cycle selected by the user based on a preset operation.

This is a result of considering maintenance because the pressure vessel 200 is exposed as the controller 900 is pivoted.

The heat dissipation fan 299 may be disposed to cool a distillation compressor 290 or to maintain air inside the cabinet 100 at a constant temperature. FIG. 1 shows an example in which the heat dissipation fan is located at a rear lower portion of the cabinet, but the heat dissipation fan may be located anywhere as long as the heat dissipation fan is able to cool the distillation compressor 290 and maintain the air inside the cabinet 100 at the constant temperature. The distillation compressor 290 may be used to compress the gaseous carbon dioxide in the distillation operation. Alternatively, heat may be supplied to the pressure vessel 200 using the high-temperature gaseous carbon dioxide compressed in a recovery operation.

The oil separator 295 may be positioned on top of the controller 900. When the controller 900 pivots, the oil separator 295 may pivot together. This is for convenient maintenance of the pressure vessel 200, the storage tank 150, the compressor, and the like of the laundry treating apparatus 1000.

When the carbon dioxide vaporized in the distillation compressor 290 is compressed at high temperature and high pressure, lubricating oil used is mixed with the carbon dioxide. The oil separator 295 is to separate the lubricating oil again. This is because, when the lubricating oil is mixed with the carbon dioxide, the lubricating oil may be mixed with the carbon dioxide used for the washing and contaminate the laundry.

FIG. 2 shows the pressure vessel 200. The pressure vessel 200 may accommodate the carbon dioxide therein at the pressure higher than the atmospheric pressure. This is because the liquid carbon dioxide is required for the washing of the laundry, and the high pressure is essential for the same. The pressure vessel 200 may include the drum 300 and the driver 500 therein.

Specifically, the pressure vessel 200 may include the first housing 211 and a second housing 221 forming an appearance of the pressure vessel. The first housing 211 may form the first chamber 210 which is the space to which the drum 300 for accommodating the laundry is inserted.

The drum 300 may be constructed to be rotatable, so that the liquid carbon dioxide and the laundry will be mixed with each other in the state in which the laundry is accommodated inside the drum 300.

The first housing 211 may have a first opening 213 defined therein that is opened on a side opposite to the vessel inlet 219 defined in a front surface of the first housing 211, that is, a side coupled to the second housing. That is, the first opening 213 may be located on the opposite side of the vessel inlet 219, and may be larger than the vessel inlet 219.

The first housing 211 may be formed in a shape of a cylinder as a whole, and may have the vessel inlet 219 defined therein having a circular shape on one side thereof, and have the first opening 213 defined therein having a circular shape on the other side.

The drum 300 may be formed in a cylindrical shape similar to the shape of the first chamber 210, which is the inner space of the first housing 211. In addition, the drum 300 may rotate in a clockwise or counterclockwise direction inside the first housing 211.

The size of the first opening 213 may be larger than a size of a cross-section of the drum 300 such that an operator or the user may withdraw the drum 300 through the first opening 213 and repair the drum 300. In this connection, the size of the first opening 213 may be greater than a size of a maximum cross-section of the drum 300. Accordingly, the operator or the like may withdraw the drum 300 by opening the first opening 213 after separating the first housing 211 and the second housing 221 from each other. In addition, it is also possible to install the drum 300 inside the first housing 211 through the first opening 213.

The first housing 211 has an inflow pipe (not shown) through which the carbon dioxide is supplied from the storage tank 150 to the first housing 211. The inflow pipe, which is a pipe exposed to the outside of the first housing 211, may flow the carbon dioxide to the interior of the first housing 211, that is, to the first chamber 210 from the storage tank 150.

The first housing 211 may include a filter assembly 350 filtering large foreign substances that do not dissolve in the liquid carbon dioxide when the liquid carbon dioxide used in the first chamber 210 flows to the distiller 400. The filter 350 may be disposed on a lower outer circumferential surface of the first housing 211. The filter 350 may include a filter insertion portion 351 formed to protrude from the cylindrical shape of the first housing 211 in a radial direction to define a space into which a filter may be inserted, and a discharge hole defined through the filter insertion part 351 to discharge the liquid carbon dioxide that has passed through the filter to the distillation tank 401.

The first housing 211 and the distillation tank 401, specifically, the discharge hole 352 and the distillation tank 401 may be connected to each other through a discharge pipe 630 (see FIG. 9).

The first housing 211 may include a first flange 212 formed along the first opening 213. The first flange 212 may extend in the radial direction along the outer circumferential surface of the first housing 211 similarly to the cylindrical shape of the first housing 211. The first flange 212 is disposed evenly along a circumference of the first housing 211 in a direction in which a radius of the first housing 211 increases.

The second housing 221 may be coupled to the first housing 211 to form one pressure vessel 200. In this connection, the interior of the pressure vessel 200 may be divided into the first chamber 210, which is a space in which laundry treatment is performed, and a second chamber 220, which is a space in which the driver 500 providing a driving force for rotating the drum is installed, by a separator 250.

Schematically, the separator 250 may be coupled to the first opening 213 in a disk shape. Therefore, the first chamber 210 of an inner space of the pressure vessel 200 may be formed by the first housing 211 and the separator 250, and the second chamber 220 may be formed by the second housing 221 and the separator 250. The drum 300 may be accommodated in the first chamber 210, and the driver 500 may be accommodated in the second chamber 220. Accordingly, a through-hole for connecting a rotation shaft (not shown) disposed in the driver 500 to the drum 300 may be defined at a center of the separator 250.

The second housing 221 may include a second flange 222 coupled to the first flange 212. The second housing 221 may be formed to have a size similar to that of the cross-section of the first housing 211 to be disposed at the rear of the first housing 211.

The second flange 222 may be coupled to the first flange 212 by a plurality of fastening members, for example, bolts and nuts, to allow an internal pressure to be maintained to be higher than an external atmospheric pressure in a state in which the second housing 221 is fixed to the first housing 211.

The filter capable of filtering the foreign substances is disposed in the filter insertion portion 351 formed in the first housing 211. The filter includes a plurality of small holes, so that, while the foreign substances are not able to pass through the holes, the liquid carbon dioxide may pass through the holes and be discharged to the outside of the first housing 211 through the discharge pipe 630. For example, the filter may be formed in a shape of a mesh.

The pressure vessel may include the separator 250 that closes the first opening 213 and is coupled to the first housing 211. The separator 250 may include a partition wall 251 for separating the first housing and the second housing from each other, a vessel heat exchanger 256 that is supported by the partition wall 251 and is able to exchange heat with the carbon dioxide accommodated in the first chamber 210, and a heat insulating member 259 disposed between the vessel heat exchanger 256 and the partition wall 251. The heat insulating member 259 is to prevent the heat of the vessel heat exchanger 256 from being transferred to the second chamber 220 through the partition wall 251.

Both the vessel heat exchanger 256 and the heat insulating member 259 may also be coupled to and supported by the partition wall 251, and the vessel heat exchanger 256 and the heat insulating member 259 may be located in the first chamber 210. On the other hand, the driver 500 may be located on the opposite side of the drum 300, that is, in the second chamber 220.

The reason for supplying the heat to the first chamber 210 or the drum 300 through the vessel heat exchanger 256 is to prevent the laundry from being hardened or damaged by a sudden drop in temperature when discharging the liquid carbon dioxide from the first chamber 210 or when discharging the gaseous carbon dioxide.

A main body of the vessel heat exchanger may be in a form of a pipe connected to meander. This is to widen a contact area with the carbon dioxide accommodated in the first chamber 210 as much as possible.

In addition, the vessel heat exchanger 256 may include a central through-portion (not shown) into which the rotation shaft of the driver 500 is inserted and passes corresponding to a size of a first through-hole 2511 (see FIG. 4) to be described later. Accordingly, the heat exchanger may be schematically formed in a donut shape. This is also the case for the heat insulating member. This is because the rotation shaft of the driver 500 passes through the separator 250 and then is connected to the drum 300.

The vessel heat exchanger 256 may operate in a scheme of supplying the heat while a refrigerant circulates, but may also use an electric heater.

FIGS. 2 and 3 show a state in which the partition wall 251 is coupled to the first housing 211, but the separator 250 may be coupled to the second housing 221.

The separator 250 may block the flow of the liquid carbon dioxide of the carbon dioxide stored in the first chamber 210 to the second chamber 220. On the other hand, the gaseous carbon dioxide of the carbon dioxide stored in the first chamber 210 may flow through the separator 250 freely. This is to reduce a stress on the partition wall by balancing a pressure between the first chamber 210 and the second chamber 220.

That is, when the high-pressure carbon dioxide is accommodated in the first chamber 210 and the second chamber is maintained at the atmospheric pressure, or the pressure of the first chamber 210 is reduced from the high pressure to the atmospheric pressure or increased from the atmospheric pressure to the high pressure, the partition wall 251 may be stressed by a pressure difference, which may cause destruction due to fatigue or deformation due to stress of the partition wall 251. To prevent this, the partition wall 251 allows the gaseous carbon dioxide to flow freely but does not allow the liquid carbon dioxide to flow freely to prevent the liquid carbon dioxide from being filled in an unnecessary portion and being wasted while maintaining the pressure difference.

To this end, a graphite gasket (not shown) may be disposed between the partition wall 251 and a seating groove 2122 to which the partition wall is coupled. In addition, all through-holes defined in the partition wall, which will be described later, may be sealed except for a second through-hole. This is to prevent the flow of the liquid carbon dioxide while allowing the gaseous carbon dioxide to flow freely.

At least one second through-hole 2512 (see FIG. 4) may be defined at an upper end of the partition wall where the liquid carbon dioxide does not reach. Therefore, the flow of the gaseous carbon dioxide is possible, so that it is possible to maintain the pressure equalization between the left and right spaces. After all, because there is no pressure difference between the first chamber 210 and the second chamber 220, the graphite gasket does not need to block the flow of the liquid carbon dioxide resulted from the pressure and simply blocks the flow by gravity, so that an excessive fastening force may not be required for the graphite gasket.

Based on FIG. 2, in the space on the left side of the partition wall 251, in the first chamber 210, the drum 300 is disposed, so that the laundry and the liquid carbon dioxide may be mixed with each other to perform the laundry treatment such as the washing operation, the rinsing operation, or the like. On the other hand, in the space on the right side of the partition wall 251, the driver 500 may be disposed to provide the driving force for rotating the drum 300. In this connection, a portion of the driver 500 may penetrate the partition wall 251 to be coupled to the drum 300.

The partition wall 251 may be formed to be larger than the first opening 213 and may be disposed to be in contact with the first opening 213 to seal the first opening 213. The partition wall 251 and the first opening 213 are formed in an approximately circular shape similar to the shape of the first housing 211. A diameter L of the first opening 213 is smaller than a diameter of the partition wall 251. The diameter L of the first opening 213 is larger than a diameter of the drum 300. Accordingly, the size of the cross-section of the drum 300 is the smallest, a cross-section of the first opening 213 has a middle size, and the size of the partition wall 251 is the largest.

The partition wall 251 is constructed to have a plurality of steps, so that strength may be secured.

The seating groove 2122 to which the partition wall 251 is coupled may be defined in the first flange 212 along the first opening 213. That is, the seating groove 2122 may be defined at a portion extended in the radial direction from the first opening 213. The seating groove 2122 may be recessed by a depth equal to greater than a thickness of the partition wall 251, so that the first flange 212 and the second flange 222 may be in contact with each other. When the seating groove 2122 is defined to be recessed by the thickness of the partition wall 251 and to have a shape corresponding to a shape of an outer circumferential surface of the partition wall 251, it may be possible to flatten a surface of the first flange 212 when the partition wall 251 is seated in the seating groove 2122.

A first seating surface 2124 extending in the radial direction further than a circumference of the seating groove 2122 is disposed in the first flange 212, and a second seating surface (not shown) in surface contact with and coupled to the first seating surface 2124 is disposed in the second flange 222. The first seating surface 2124 and the second seating surface are disposed to be in contact with each other, so that the carbon dioxide injected into the inner space of the first housing 211 is prevented from being discharged to the outside. The first seating surface 2124 and the second seating surface may be respectively disposed on outer circumferential surfaces of the first housing 211 and the second housing 221 to provide a coupling surface where the two housings may be coupled to each other by a fastening member while being in surface contact with each other.

The vessel heat exchanger 256 from which the refrigerant flows into the first chamber 210 in which the drum is accommodated may be disposed on the partition wall 251, and the vessel heat exchanger 256 may be disposed in the space defined by the first housing 211 and the partition wall 251. It is possible to increase the temperature of the first chamber 210 through the vessel heat exchanger 256, which is to prevent the laundry accommodated in the drum 300 from being hardened or damaged by a sudden drop in temperature of the first chamber 210 when discharging the liquid carbon dioxide from the first chamber 210 to the distillation tank 401 or when recovering the gaseous carbon dioxide or discharging the gaseous carbon dioxide to the outside.

The heat insulating member 259 may be disposed between the vessel heat exchanger 256 and the partition wall 251. The heat insulating member 259 is to block transfer of the temperature of the vessel heat exchanger 256 to the partition wall 251 to increase a heat exchange efficiency of the vessel heat exchanger 256.

The heat insulating member 259 reduces an influence of the temperature change of the vessel heat exchanger 256 on the partition wall 251. The heat insulating member 259 may be formed similarly to the vessel heat exchanger 256 so as to cover an entire area of the vessel heat exchanger 256.

FIG. 3 shows a state in which the second housing is separated from the first housing in FIG. 2.

When the second housing 221 is separated from the first housing 211, the partition wall 251 will be exposed to the outside. Because the partition wall 251 is coupled to the seating groove of the first housing 211, even when the second housing 221 is separated from the first housing 211, the inner space of the first housing 211 will not be exposed to the outside. The partition wall 251 may include a plurality of third through-holes 2513. Therefore, the partition wall may be coupled to the first housing 211 by a plurality of fastening members, for example, bolts.

The partition wall 251 may be coupled to the driver 500 through the first through-hole 2511 (see FIG. 4) defined at the center of the partition wall 251, and at least one second through-hole 2512 is defined above the driver 500. Each of

refrigerant pipes

2567 and 2568 for circulating the refrigerant to transfer the heat through the vessel heat exchanger 256 may pass through the at least one second through-hole 2512.

FIG. 3 shows the two second through-holes 2512 through which the first pipe 2567 and the second pipe 2568 respectively pass, but this is only an example. The first pipe 2567 and the second pipe 2568 may pass through one second through-hole. The first pipe 2567 and the second pipe 2568 will be connected to the vessel heat exchanger 256 to circulate the refrigerant. That is, when the refrigerant flows into the first pipe 2567, the refrigerant will flow out through the second pipe 2568.

In this connection, the refrigerant may be the gaseous carbon dioxide compressed through the distillation compressor 290 rather than a separate refrigerant. Because the gaseous carbon dioxide compressed for the distillation is in a high-temperature and high-pressure state, the gaseous carbon dioxide may be used to raise an internal temperature of the pressure vessel 200 through the vessel heat exchanger 256 disposed inside the pressure vessel 200.

After the high-temperature refrigerant is supplied through the first pipe 2567 and exchanges the heat with the carbon dioxide inside the first chamber 210 through the vessel heat exchanger 256, the cooled refrigerant will be discharged through the second pipe 2568.

When the partition wall 251 is separated from the first housing 211, the first opening 213 will be exposed. In this connection, the drum 300 may be withdrawn to the outside through the first opening 213. Because the size of the first opening 213 is larger than the size of the drum 300, maintenance of the drum 300 is possible through the first opening 213.

A gasket (not shown) is disposed between the partition wall 251 and the seating groove 2122. Accordingly, when the partition wall 251 is coupled to the first housing 211, it is possible to prevent the carbon dioxide from leaking to the space between the partition wall 251 and the seating groove 2122. When the partition wall 251 is seated in the seating groove 2122, the partition wall 251 may be coupled to the seating groove 2122 by a plurality of fastening members while pressing the gasket. The plurality of third through-holes 2513 (see FIG. 4) for coupling to the first housing 211 may be evenly defined in the partition wall 251 along an outer circumferential surface of the partition wall 251.

In addition, the partition wall 251 may be coupled to the driver 500 to support the driver 500. Because the rotation shaft of the driver 500 passes through the separator 250 and is connected to the drum 300, the partition wall may eventually serve to support both the drum 300 and the driver 500.

(a) and (b) in FIG. 4 are views of the partition wall 251 viewed from the front and the side, respectively.

Referring to (a) in FIG. 4, the first through-hole 2511 through which the rotation shaft of the driver 500 passes to be coupled with the drum 300 may be defined at the center of the partition wall 251. The first through-hole 2511 may have a circular shape, so that interference thereof with the rotation shaft passing through the first through-hole 2511 may be prevented.

In addition, the partition wall 251 may further include the at least one second through-hole 2512 for allowing the gaseous carbon dioxide to freely flow between the first chamber 210 and the second chamber 220. The at least one second through-hole 2512 may be defined at a higher position than the first through-hole 2511. A maximum liquid level of the liquid carbon dioxide is lower than a vertical level at which the at least one second through-hole 2512 is located with respect to the bottom surface, so that the liquid carbon dioxide may be prevented from flowing through the at least one second through-hole 2512.

Normally, an amount of liquid carbon dioxide used in the washing operation or the rinsing operation does not exceed half of the drum 300. That is, the liquid carbon dioxide does not flow up to a vertical level equal to or higher than a vertical level of the rotation shaft of the driver 500 coupled to the drum 300, that is, a minimum vertical level of the first through-hole with respect to the bottom surface (a vertical level of a center of the first through-hole - a radius of the first through-hole).

Therefore, when the second through-hole 2512 is located at the higher position than the first through-hole 2511, no liquid carbon dioxide will flow through the second through-hole 2512. On the other hand, because the gaseous carbon dioxide is filled in the space defined by the first housing 211 and the partition wall 251, the gaseous carbon dioxide may freely flow into the space defined by the second housing 221 and the partition wall 251 to achieve the pressure equalization.

That is, while the laundry treatment such as the washing operation or the rinsing operation is performed, in the space partitioned by the first housing 211 and the partition wall 251, the gaseous carbon dioxide and the liquid carbon dioxide are mixed. On the other hand, in the space partitioned by the second housing 221 and the partition wall 251, the liquid carbon dioxide does not exist and only the gaseous carbon dioxide exists. Because the two spaces are in the state of pressure equilibrium, the liquid carbon dioxide may not need to exist in the space defined by the second housing 221 and the partition wall 251, and an amount of liquid carbon dioxide used may be reduced.

Therefore, the total amount of carbon dioxide used for the washing operation, the rinsing operation, or the like may be reduced, so that the amount of carbon dioxide used is reduced compared to that in the prior art. This will reduce an amount of carbon dioxide that has to be reprocessed after the use.

As the amount of carbon dioxide used is reduced, a capacity of the tank for storing the carbon dioxide may be reduced, as well as an overall size of the washing machine for using the carbon dioxide. In addition, because an amount of carbon dioxide that has to be distilled after the use is reduced, a time it takes for the washing cycle may be reduced.

In addition, the

refrigerant pipes

2567 and 2568 may pass through the at least one second through-hole 2512 as described above. Accordingly, the size of the at least one second through-hole 2512 may be larger than outer diameters of the

refrigerant pipes

2567 and 2568.

The partition wall 251 is a part that may be separated from the first housing 211 or the second housing 221. The vessel heat exchanger 256, the heat insulating member 259, and the driver 500 may be coupled to and supported by the partition wall 251. In order to couple the vessel heat exchanger 256 and the heat insulating member 259 to the partition wall 251, a plurality of fourth through-holes 2514 through which the fastening member passes may be defined in a radial direction of the first through-hole 2511.

(a) in FIG. 4 shows a state in which the plurality of fourth through-holes 2514 are paired by two and the three pairs are arranged at spacings of 120 º (degrees), but this is only one embodiment. The shape and the arrangement of the fourth through-holes 2514 are not limited as long as the fourth through-holes 2514 are able to support the vessel heat exchanger 256 and the heat insulating member 259 by coupling the vessel heat exchanger 256 and the heat insulating member 259 to the partition wall 251.

In addition, when the partition wall 251 is separated from the first housing 211, it is possible to provide an environment in which the user or the like may separate the drum 300 from the first housing 211.

The partition wall 251 may be stepped forwardly or rearwardly a plurality of times, and strength thereof may be increased. In addition, the partition wall 251 may have a curved surface in some sections, so that the partition wall 251 may be formed to withstand forces in various directions.

An outermost portion of the partition wall 251 may have a shape coupled to the seating groove 2122 of the first housing 211. In addition, the partition wall 251 may include the plurality of third through-holes 2513 in a portion corresponding to the seating groove 2122 to be coupled to the first housing 211 using the fastening member after being coupled to the seating groove 2122.

Based on (b) in FIG. 4, in a direction from the outermost portion of the partition wall 251 to a central portion, the partition wall 251 may be stepped by various lengths in various directions, such as protruding leftwards, then protruding rightwards, and then protruding leftwards again, so that the strength may be increased.

FIGS. 5 to 8 schematically show a flow path of the carbon dioxide in a main stage of forming the washing cycle in order to illustrate the washing cycle of the laundry treating apparatus using the carbon dioxide as the washing solvent.

Referring to FIG. 5, the laundry treating apparatus using the carbon dioxide as the washing solvent may include the pressure vessel 200 that accommodates the laundry therein and performs the washing and the rinsing using the supplied carbon dioxide, the storage tank 150 that stores the used carbon dioxide after the distillation and supplies the carbon dioxide to the pressure vessel (or the washing chamber) 200, and the distiller 400 that distills the carbon dioxide emitted after the use.

The pressure vessel 200 may further include the filter assembly 350 for removing the foreign substances insoluble in the liquid carbon dioxide discharged after the use. As described above, the filter assembly 350 may be disposed on the lower surface of the pressure vessel 200. However, the present drawing illustrates an example in which the filter assembly 350 is independently disposed between the pressure vessel 200 and the distiller 400.

In addition, the laundry treating apparatus 1000 may further include a replenishment tank 155 (see FIG. 6) for replenishing the carbon dioxide lacking in the pressure vessel 200.

The distiller 400 is to remove the foreign substances from the carbon dioxide used in the washing operation and the rinsing operation, that is, the carbon dioxide used in the pressure vessel, and then distill the carbon dioxide for the reuse. As described above, in order to remove the foreign substances from the liquid carbon dioxide, particularly foreign substances dissolved in the liquid carbon dioxide, only the liquid carbon dioxide should be vaporized and then cooled again.

To this end, the conventional distiller 400 may include the distillation tank 401 for storing the carbon dioxide discharged from the pressure vessel, the compressor 290 located outside the distillation tank 401 and sucking and compressing the gaseous carbon dioxide from the distillation tank 401, and an internal heat exchanger 410 located inside the distillation tank 401 and connected to the compressor 290 to exchange the heat of the compressed gaseous carbon dioxide with the liquid carbon dioxide stored inside the distillation tank 401.

The conventional distiller 400 may further include a cooler 160 for liquefying the distilled carbon dioxide.

In addition, the conventional laundry treating apparatus may further include a plurality of pipes for connecting components with each other and a plurality of valves or a controller for controlling the flow of the carbon dioxide along the plurality of pipes. This is described using FIGS. 9 and 10. FIG. 5 schematically shows each component, so that the plurality of valves or the controller is omitted, and the plurality of pipes are indicated by lines. In addition, a flow direction of the carbon dioxide is indicated by an arrow.

A triple point of the carbon dioxide (CO2) is known to be 5.1 atm and -56.6 ℃. Therefore, a phase change from a solid (dry ice) to a gas occurs when the temperature is changed under a pressure lower than the triple point, whereas, under a pressure higher than the triple point, the carbon dioxide exists as a liquid and a gas, so that a phase change between a liquid and a gas may occur depending on given pressure and temperature.

Therefore, when the carbon dioxide is pressurized, like using water as the washing solvent in a general laundry treating apparatus, the liquid carbon dioxide (CO2(L) or L-CO2) may be used as the washing solvent. However, in a case of a water-soluble substance, washing power using the carbon dioxide is low, so that a detergent or a surfactant may be additionally used to remove water-soluble substances.

A fluid other than the carbon dioxide may be used as the washing solvent. The fluid may be a fluid whose phase change from a gas to a liquid occurs or that may be in a state of supercritical fluid when pressurized at a predetermined temperature.

When the carbon dioxide is used as the washing solvent, all of the carbon dioxide evaporates into gas when a pressure thereof is reduced to the atmospheric pressure after the washing cycle is completed. Therefore, there is no need to go through a separate drying cycle that requires a long time, and there is no odor even when there is residual carbon dioxide. However, because the carbon dioxide is used by being pressurized, unlike a tub of the general laundry treating apparatus, a sealed pressure vessel is required to prevent the carbon dioxide from leaking.

Therefore, the pressure vessel 200 is an airtight container from which the pressurized carbon dioxide is not able to escape, and must be formed as a tank that may withstand the pressure of the pressurized carbon dioxide. This is also true for the storage tank 150, the replenishment tank 155, and the distillation tank 401.

FIGS. 6 to 8 show major stages of the washing cycle of the conventional laundry treating apparatus using the carbon dioxide as the washing solvent.

(a) in FIG. 6 shows the pressurization operation prior to the washing process in the washing cycle of the conventional laundry treating apparatus using the carbon dioxide as the washing solvent.

When the user selects the washing cycle described above, prior to the pressurization operation, the controller 900 may open a purge valve 298 disposed in the pressure vessel, and remove the air inside the pressure vessel 200 using a vacuum pump (not shown). This is because the washing power of the carbon dioxide for the laundry may be reduced when the air remains in the pressure vessel and contains moisture.

In addition, the pressure inside the pressure vessel 200 may be lower to a pressure lower than the atmospheric pressure, preferably close to vacuum, by discharging the residual air remaining after opening of the purge valve 298 using a pump (not shown).

Thereafter, a top of the storage tank 150 may be opened to supply the gaseous carbon dioxide to the pressure vessel 200 to pressurize the pressure vessel 200. Because the internal pressure of the storage tank 150 is higher than the internal pressure of the pressure vessel 200, the gaseous carbon dioxide will flow from the storage tank 150 to the pressure vessel until the internal pressure of the storage tank 150 is equal to the internal pressure of the pressure vessel 200.

Accordingly, the pressurization operation will continue until the pressures of the storage tank 150 and the pressure vessel 200 are in equilibrium. In this connection, when the pressure vessel 200 is divided into the first chamber 210 and the second chamber 220 by the separator 250 as described above, the liquid carbon dioxide and the gaseous carbon dioxide will coexist in phase equilibrium in the first chamber 210, and the second chamber 220 will be filled with the gaseous carbon dioxide having the same pressure as that of the first chamber 210.

In the storage tank 150, carbon dioxide used in a previous washing cycle may be distilled and stored. The storage tank 150 is also the tank capable of withstanding the high pressure. In the storage tank 150, a portion of the carbon dioxide which may be stored as the gaseous carbon dioxide and the rest may be stored as the liquid carbon dioxide. Therefore, the carbon dioxide may be supplied to the pressure vessel 200 by opening the top of the storage tank 150.

In this connection, the storage tank 150 and the pressure vessel 200 will supply the carbon dioxide to the pressure vessel 200 until the pressure equilibrium is achieved. Therefore, the pressure in the storage tank 150 will decrease, which in turn will decrease the temperature. In the storage tank 150, the gaseous carbon dioxide and the liquid carbon dioxide coexist. When the liquid carbon dioxide is put into the pressure vessel 200 whose pressure is close to the vacuum, the temperature will drop rapidly as all of the liquid carbon dioxide vaporizes, so that the laundry may be damaged. To prevent this, the gaseous carbon dioxide may be injected first.

(b) in FIG. 6 shows another embodiment of the pressurization operation. Even when the liquid carbon dioxide used in the washing and rinsing operations is distilled and used again as the carbon dioxide used in the washing cycle, when considering slight loss or the like caused by opening the purge valve 298 at the beginning of the washing cycle and discharging the residual carbon dioxide to the outside after the washing cycle, the amount of carbon dioxide stored inside the laundry treating apparatus will be gradually reduced. Therefore, it is necessary to supplement the carbon dioxide, so that the replenishment tank 155 may be further disposed. The liquid carbon dioxide is filled in the replenishment tank 155, and is able to be supplied to the pressure vessel 200.

(a) in FIG. 7 shows the supply operation of supplying the carbon dioxide to the pressure vessel 200 using the vertical level difference between the storage tank 150 and the pressure vessel after the pressurization operation is completed.

After the pressurization operation is completed, the pressure vessel 200 will maintain a predetermined pressure, for example 50 bar. In this connection, in the pressure vessel 200, the liquid carbon dioxide and the gaseous carbon dioxide will coexist in the phase equilibrium. However, in order to secure sufficient the liquid carbon dioxide for the washing, a bottom of the storage tank 150 is opened to supply the liquid carbon dioxide. In this connection, the liquid carbon dioxide may be supplied by the vertical level difference between the pressure vessel 200 and the storage tank 150 rather than the pressure. To this end, the storage tank 150 may be located above the pressure vessel 200 with respect to the bottom surface.

Alternatively, the installation vertical level of the storage tank 150 may be higher than the installation vertical level of the pressure vessel 200. That is, the vertical level of the center of the circular cross-section of the storage tank 150 with respect to the bottom surface of the cabinet may be higher than the vertical level of the center of the circular cross-section of the pressure vessel 200.

In addition, the gaseous carbon dioxide communicates between the upper portion of the storage tank 150 and the pressure vessel 200. This is indicated by a double-headed arrow on the flow path of the carbon dioxide in (a) in FIG. 7.

When the liquid carbon dioxide is filled to a predetermined vertical level inside the pressure vessel 200 in the supply operation, the controller 900 may rotate the drum 300 at the preset first rotation speed to proceed with the washing operation. The liquid level of the liquid carbon dioxide may allow that the liquid carbon dioxide of a preset flow rate may be supplied to the pressure vessel 200 using a liquid level sensor or by the controller 900 controlling the valve for a preset time.

(b) in FIG. 7 shows a rinsing preparation operation, after the washing is complete and before performing the rinsing, of supplying the carbon dioxide to the pressure vessel 200 using the vertical level difference between the storage tank 150 and the pressure vessel 200 to recover the liquid carbon dioxide inside the pressure vessel 200.

The liquid carbon dioxide used in the pressure vessel 200 may contain the foreign substances removed from the laundry. The liquid carbon dioxide discharged from the pressure vessel 200 to remove the foreign substances may be supplied into the distillation tank 401 through the filter (not shown).

As described above, the foreign substances insoluble in the liquid carbon dioxide may be filtered through the filter assembly 350, and the foreign substances dissolved in the liquid carbon dioxide are removed through the distillation through the distiller 400, so that only the purified liquid carbon dioxide may be obtained for the reuse.

The liquid carbon dioxide discharged from the pressure vessel 200 will be discharged to the distillation tank 401 by the vertical level difference between the pressure vessel 200 and the distillation tank 401, not the pressure difference. To this end, the distillation tank 401 may be located below the pressure vessel 200 with respect to the bottom surface. In addition, this is to prevent unnecessary energy wastage during the flow of the liquid carbon dioxide.

In this connection, for pressure equilibrium of the components, the storage tank 150, the distillation tank, and the pressure vessel 200 are in communication with each other, so that the gaseous carbon dioxide may freely flow between the storage tank 150, the distillation tank, and the pressure vessel 200. This is indicated by double-headed arrows on the flow path of the carbon dioxide.

The liquid carbon dioxide discharged after the use from the pressure vessel 200 fills the distillation tank 401. Instead of the discharged liquid carbon dioxide, clean liquid carbon dioxide supplied from the bottom of the storage tank 150 will fill the empty space in the pressure vessel 200. This is for the subsequent rinsing operation.

(a) in FIG. 8 shows the distillation operation, between the washing operation and the rinsing operation, between the rinsing operation and another rinsing operation, or after both the washing operation and the rinsing operation are complete, of distilling the liquid carbon dioxide discharged from the pressure vessel 200 to the distillation tank 401.

After the rinsing preparation operation, the controller 900 performs the rinsing operation of removing the remaining foreign substances by rotating the drum 300 at a preset second rotation speed.

During the washing operation or the rinsing operation, or after the rinsing operation is completed, the distillation of the carbon dioxide may be performed in the distiller 400.

The distiller 400 may include the distillation compressor 290 located outside the distillation tank 401 and sucking and compressing the gaseous carbon dioxide of the carbon dioxide stored in the distillation tank 401, the internal heat exchanger 410 located inside the distillation tank 401 and connected to the distillation compressor 290 to exchange the heat of the compressed gaseous carbon dioxide with the liquid carbon dioxide stored in the distillation tank 401, and a storage pipe 610 for flowing the carbon dioxide past the internal heat exchanger 410 to the storage tank.

In addition, the distillation compressor 290 may be connected to the distillation tank 401 through a compression pipe 640. The compression pipe 640 may include a suction pipe 641 that connects the distillation tank 401 and the distillation compressor 290 to each other to suck the gaseous carbon dioxide and transfer the gaseous carbon dioxide to the distillation compressor 290, and a discharge pipe 651 that connects the distillation compressor 290 and the internal heat exchanger 410 to each other to discharge the gaseous carbon dioxide compressed at the high temperature and the high pressure to the internal heat exchanger 410.

The distillation compressor 290 may be a general compressor capable of compressing the gaseous carbon dioxide.

The liquid carbon dioxide and the gaseous carbon dioxide stored in the distillation tank 401 will be in the phase equilibrium. Only the liquid carbon dioxide is in the state of being mixed with no foreign substances, and the gaseous carbon dioxide exists with the foreign substances because the foreign substances are not vaporized.

Because the pressure inside the distillation tank 401 distills the carbon dioxide stored in the distillation tank 401 and continuously flows the carbon dioxide to the storage tank 150, as the distillation progresses, the pressure inside the distillation tank 401 may be lowered. That is, when the distillation compressor 290 operates, the pressure inside the distillation tank 401 will drop by a suction power of the distillation compressor 290. Accordingly, the vaporization of the liquid carbon dioxide will proceed. Therefore, in general, the internal pressure of the distillation tank 401 will be lower than the internal pressure of the storage tank 150. Therefore, in order to transfer the carbon dioxide to the storage tank 150, it must be compressed to have the internal pressure equal to or higher than the internal pressure of the storage tank 150. The distillation compressor 290 may be required for this.

The internal heat exchanger 410 is for the heat exchange between the compressed gaseous carbon dioxide and the liquid carbon dioxide accommodated in the distillation tank. Because the compressed gaseous carbon dioxide is in the high-temperature and high-pressure state, the gaseous carbon dioxide may be stored in the storage tank 150 after lowering the temperature thereof. Preferably, the gaseous carbon dioxide may be stored after changing the phase to the liquid carbon dioxide by lowering the temperature.

To this end, in terms of energy efficiency, it is preferable to use the heat of the compressed gaseous carbon dioxide for the evaporation of the liquid carbon dioxide stored in the distillation tank rather than cooling using a separate cooler, so that the internal heat exchanger 410 as described above may be used.

In addition, in the distiller 400, the storage pipe 610 that connects the internal heat exchanger 410 and the storage tank 150 to each other to flow the carbon dioxide that has passed through the internal heat exchanger 410 to the storage tank 150 may further include the cooler 160 for cooling the flowing carbon dioxide.

As such, the liquid carbon dioxide mixed with the foreign substances is vaporized through the distiller 400 to remove the foreign substances therefrom. In this connection, a necessary vaporization heat is obtained through the heat exchange with the already vaporized and compressed gaseous carbon dioxide.

However, in the process of using the distillation compressor 290, oil for smooth operation of the distillation compressor 290 may be used. This eventually mixes with the compressed gaseous carbon dioxide, so that the distiller 400 may further include an oil separator 295 (see FIG. 1) for separating the oil from the compressed gaseous carbon dioxide on the storage pipe 610.

(b) in FIG. 8 shows the recovery operation of recovering the gaseous carbon dioxide remaining in the pressure vessel 200 after discharging the liquid carbon dioxide stored in the pressure vessel 200 for the distillation after all the washing and rinsing operations are completed.

The distillation methods are all the same, but a difference exists for recovering and reusing the gaseous carbon dioxide as much as possible because the gaseous carbon dioxide does not need to remain in the pressure vessel 200 anymore after the rinsing operation is completed.

(b) in FIG. 8 shows a recovery operation of recovering the gaseous carbon dioxide remaining in the pressure vessel 200 and removing residual gas before completing the washing cycle after the rinsing operation.

As described above, the distillation operation refers to the operation of vaporizing the liquid carbon dioxide in the pressure vessel 200 to remove the foreign substances, and then storing the purified liquid carbon dioxide in the storage tank. In contrast, the recovery operation refers to the operation of recovering the gaseous carbon dioxide present in the pressure vessel 200 and storing the gaseous carbon dioxide in the storage tank 150 after the compression. This is because there is no need for the gaseous carbon dioxide to pass through the filter or go through the complicated distillation operation as the gaseous carbon dioxide does not mix with the foreign substances.

The distillation compressor 290 may be used not only in the distillation operation, but also in the recovery operation. That is, in order to transfer the heat through the vessel heat exchanger 256 disposed between the partition wall 251 and the drum 300 inside the first chamber 210, the separate refrigerant may be used, but the gaseous carbon dioxide compressed through the distillation compressor 290 may be used as the refrigerant. This is possible by simply opening and closing the connection pipe without using the separate compressor that takes up a lot of space to compress the refrigerant.

Unlike in the distillation operation, the carbon dioxide compressed in the distillation compressor 290 may pass through the vessel heat exchanger 256, then is liquefied by passing through the cooler 160, and then, stored in the storage tank 150. Such flow path of the carbon dioxide may be adjusted based on the opening and closing of the connection pipe and the valve (not shown).

The reason the gaseous carbon dioxide inside the pressure vessel 200 passes through the vessel heat exchanger 256 after being compressed through the distillation compressor 290 is that, when the pressure of the pressure vessel 200 drops and accordingly the temperature drops as the gaseous carbon dioxide is recovered, the gaseous carbon dioxide that has not been recovered yet is liquefied, which may damage the laundry. This is to maintain the temperature in the pressure vessel 200 at the preset temperature in the recovery operation to prevent the above situation.

In addition, when the pressure inside the pressure vessel 200 goes down to a certain pressure, for example, a pressure equal to or lower than 1.5 bar, the purge valve 298 will be finally opened to discharge the remaining gaseous carbon dioxide. This may result in a small loss of the carbon dioxide supplied during the washing cycle in the storage tank. Therefore, as described above, the replenishment tank 155 may be required to replenish the lacking carbon dioxide in a next washing cycle.

(b) in FIG. 8 shows an example of heat exchange in which the heat of the high-temperature and high-pressure gaseous carbon dioxide that has passed through the distillation compressor 290 is directly transferred to the pressure vessel 200 by connecting the distillation compressor 290 and the pressure vessel 200 to each other through a separate pipe. However, because this uses the distillation compressor 290, more energy may be used. Therefore, in terms of energy saving, instead of transferring the high-temperature and high-pressure gaseous carbon dioxide that has passed through the distillation compressor 290 to the pressure vessel 200, the liquid carbon dioxide flowing through the internal heat exchanger 410 to the storage tank 150 may be used.

That is, the liquid carbon dioxide flowing through the internal heat exchanger 410 to the storage tank 150 may not be sufficiently cooled to a desired temperature. Therefore, when the liquid carbon dioxide flows to the storage tank 150 through the pressure vessel 200, the temperature of the pressure vessel 200 may be raised using the heat of the liquid carbon dioxide. This is because the liquid carbon dioxide has to be cooled using the separate cooler anyway before being introduced into the storage tank 150 when the liquid carbon dioxide flowing through the internal heat exchanger 410 to the storage tank 150 is not sufficiently cooled to the desired temperature.

The liquid carbon dioxide flowing to the storage tank 150 by passing through the internal heat exchanger 410 may flow to the storage tank 150 by passing through the vessel heat exchanger 256, or may flow to the storage tank 150 by passing through the separate heat exchanger inside the pressure vessel 200. Therefore, it is possible to save energy required for the distillation compressor and energy required for the separate cooler.

In the case of the conventional laundry treating apparatus using the carbon dioxide as the washing solvent, as the amount of carbon dioxide stored in the storage tank 150, an amount of carbon dioxide needed for the rinsing operation that generally requires the greatest amount of liquid carbon dioxide may be stored. Because the rinsing operation may be generally repeated twice, an amount required for the two rinsing operations may be stored. However, this eventually increases a size and a weight of the storage tank 150, so that there is a problem in miniaturization of the laundry treating apparatus. To solve this, in order to reduce the amount of carbon dioxide stored in the storage tank 150, after reducing the amount of carbon dioxide based on an operation that requires a larger amount among the washing operation or the one rinsing operation, the carbon dioxide may be distilled and reused in the washing operation or the rinsing operation.

Therefore, unlike the general laundry treating apparatus that simply receives water from the outside and performs the washing cycle, the distillation operation is required during the washing cycle. To this end, additional time is required to distill the carbon dioxide in addition to time required for the washing cycle.

Because the additional distillation time eventually causes inconvenience to consumers, it is necessary to shorten the distillation time as much as possible.

In addition, in the case of the conventional laundry treating apparatus using the carbon dioxide as the washing solvent, as described above, the internal pressure of the distillation tank 401 is continuously lowered, which will result in a decrease in the flow rate of the gaseous carbon dioxide sucked into the compressor due to a decrease in a density of the gaseous carbon dioxide. Eventually, a regeneration efficiency of the internal heat exchanger 410 will be lowered as much as the reduced flow rate. The regeneration efficiency refers to a heat exchange efficiency between high-temperature gaseous carbon dioxide and low-temperature liquid carbon dioxide.

In addition, in order for the internal heat exchanger 410 to operate normally, it may be preferable to be immersed in the liquid carbon dioxide. However, the regeneration efficiency is gradually lowered due to the lowering of the liquid level of the liquid carbon dioxide. To prevent this, inside the distillation tank 401, the internal heat exchanger 410 should be located as close to the bottom surface as possible. However, because the distillation tank 401 is also a kind of high-pressure tank, a shape of the distillation tank will preferably be cylindrical in order to minimize internal stress. As a result, as an area of the interior of the distillation tank 401 decreases downwardly, a shape of the internal heat exchanger 410 should also be matched therewith. This eventually has a problem in that a heat exchange area is rapidly reduced when the liquid level is lowered.

FIG. 9 shows the distillation operation of the laundry treating apparatus additionally having the external heat exchanger outside the distillation tank to solve the above problems. In order to focus on the distillation operation, components unnecessary for the description are omitted. In addition, a plurality of pipes and valves for respectively controlling the pipes shown in FIG. 9 are only an example. The plurality of pipes may be connected differently and the valves of the respective pipes may be opened and closed differently as long as the carbon dioxide may be flowed in a desired direction.

Referring to FIG. 9, the laundry treating apparatus 1000 described in the present disclosure includes the pressure vessel 200 that maintains the carbon dioxide accommodated therein at the pressure higher than the atmospheric pressure, the storage tank 150 located above the pressure vessel 200 to store the carbon dioxide and supply the carbon dioxide to the pressure vessel 200, and the distiller 400 that is located below the pressure vessel 200, vaporizes the liquid carbon dioxide of the carbon dioxide discharged from the pressure vessel 200 to remove the foreign substances therefrom, and then liquefies the vaporized carbon dioxide and supplies the liquefied carbon dioxide to the storage tank 150.

In addition, the distiller 400 may include the distillation tank 401 that stores the carbon dioxide discharged from the pressure vessel 200, a circulation flow path 660 located outside the distillation tank 401 to circulate the liquid carbon dioxide stored in the distillation tank 401, and an external heat exchanger 490 that is located on the circulation flow path 660 and supplies the heat to, that is, heats, the liquid carbon dioxide passing through the circulation flow path 660 using external heat.

In addition, the distiller 400 may further include the suction pipe 641 that connects the distillation tank 401 and the distillation compressor 290 to each other to flow the gaseous carbon dioxide from the distillation tank to the distillation compressor 290, the discharge pipe 651 that connects the distillation compressor 290 and the internal heat exchanger 410 to each other to flow the compressed gaseous carbon dioxide to the internal heat exchanger 410, and the storage pipe 610 that connects the internal heat exchanger 410 and the storage tank 150 to each other to flow the compressed gaseous carbon dioxide to the storage tank 150.

FIG. 9 shows schematic pipes and valves required for the distillation. The opening and closing of the pipe using the valve may be controlled by the controller 900.

The storage tank 150 and the pressure vessel 200 may be connected to each other through a supply pipe 620, and a supply control valve 625 may be positioned on the supply pipe 620. The controller 900 may open the supply control valve 625 to flow the carbon dioxide stored in the storage tank 150 to the pressure vessel 200 in the pressurization operation and the supply operation. Specifically, pipes along which the liquid carbon dioxide and the gaseous carbon dioxide respectively flow may be separately disposed, but are briefly illustrated here.

For the distillation, the liquid carbon dioxide used in the pressure vessel 200 will have to be discharged to the distiller 400 when the washing operation or the rinsing operation is completed. To this end, the pressure vessel 200 and the distillation tank 401 may be connected to each other by the discharge pipe 630, and opening and closing of the discharge pipe 630 may be controlled by a discharge control valve 635 disposed on the discharge pipe 630. The distillation tank 401 is positioned below the pressure vessel 200. Thus, the liquid carbon dioxide may flow from the pressure vessel 200 to the distillation tank 401 using gravity resulted from the vertical level difference.

When the inner space of the pressure vessel 200 is divided into the first chamber 210 and the second chamber 220 as described above, the storage pipe 610, the supply pipe 620, and the discharge pipe 630 may pass through the first housing 211 to be connected to the first chamber 210.

Because the pressure inside the distillation tank 401 is lower than the pressure of the pressure vessel 200, the liquid carbon dioxide will be vaporized to form the gaseous carbon dioxide, and the liquid carbon dioxide and the gaseous carbon dioxide will maintain the phase equilibrium at the corresponding temperature and pressure.

When the distillation compressor 290 starts to operate, because the internal pressure of the distillation tank 401 is gradually decreased, the amount of gaseous carbon dioxide will increase and the amount of liquid carbon dioxide will decrease. As a result, the more the distillation compressor 290 operates in the distillation operation, the more the pressure inside the distillation tank will decrease, the more the density of the gaseous carbon dioxide will decrease, and the more the liquid level of the liquid carbon dioxide will decrease.

The distillation compressor 290 may be located on the compression pipe 640. The compression pipe 640 may include the suction pipe 641 that connects the distillation tank and the distillation compressor 290 to each other, and the discharge pipe 651 that connects the distillation compressor 290 and the internal heat exchanger to each other. Opening and closing of the suction pipe 641 may be controlled by the suction control valve 645, and opening and closing of the discharge pipe 651 may be controlled by the discharge control valve 655.

The gaseous carbon dioxide stored in the distillation tank 401 may be introduced into the distillation compressor 290 through the suction pipe 641, and the gaseous carbon dioxide compressed at high temperature and high pressure in the distillation compressor 290 through the discharge pipe 651 may be discharged to the internal heat exchanger 410.

Because the gaseous carbon dioxide is located at the upper portion of the distillation tank 401, for the suction of the gaseous carbon dioxide, one end of the suction pipe may be connected to the distillation tank 401 through the top of the distillation tank 401.

The internal heat exchanger 410 will be located on the bottom surface of the distillation tank 401 so as to be immersed in the liquid carbon dioxide as much as possible inside the distillation tank 401. In the internal heat exchanger 410, similar to the conventional heat exchanger, the pipe along which the gaseous carbon dioxide passes inside is meanderingly connected, which may increase an area of contact with the liquid carbon dioxide, thereby facilitating the heat transfer.

Therefore, the high-temperature, high-pressure gaseous carbon dioxide discharged as such will be cooled by the liquid carbon dioxide while passing through the internal heat exchanger 410. On the other hand, the liquid carbon dioxide will receive the heat of the high-temperature, high-pressure gaseous carbon dioxide passing through the internal heat exchanger 410 and use the received heat as evaporation heat.

In addition, the internal heat exchanger 410 and the storage tank 150 may be connected to each other through the storage pipe 610. The controller 900 may control opening and closing of the storage pipe 610 by controlling a storage control valve 615 disposed on the storage pipe 610.

In one example, a back flow preventing valve 617 for preventing the carbon dioxide flowing to the storage tank 150 from flowing backward may be further disposed on the storage pipe 610. The back flow preventing valve 617, which is a kind of one-way valve, does not need to be actively controlled by the controller 900.

However, in order to solve the above problems in the distillation process, the laundry treating apparatus 1000 may further include the circulation flow path 660 that is located outside the distillation tank 401 and circulates the liquid carbon dioxide, and the external heat exchanger 490 located on the circulation flow path 660.

The circulation flow path 660 may include a first circulation pipe 661 that flows the liquid carbon dioxide introduced from the distillation tank 401 to the external heat exchanger 490, and a second circulation pipe 671 that flows the liquid carbon dioxide past the external heat exchanger 490 back to the distillation tank.

The controller 900 may control opening and closing of the first circulation pipe 661 and the second circulation pipe 671 through a first circulation control valve 665 and a second circulation control valve 675 disposed on the first circulation pipe 661 and the second circulation pipe 671, respectively.

Because the liquid carbon dioxide is located in the lower portion of the distillation tank 401, it may be preferable that one end of the first circulation pipe 661 is connected to the distillation tank 401 through the bottom of the distillation tank 401 for the introduction of the liquid carbon dioxide.

On the other hand, it may be advantageous for the second circulation pipe 671 to extend downwards from a portion above the distillation tank 401 in order to transfer the heat to the interior of the distillation tank 401. Accordingly, the second circulation pipe 671 may be directly connected to the top of the distillation tank 401, or may be connected to the discharge pipe 630 and connected to the distillation tank 401.

The distiller 400 may further include a circulation pump 450 positioned on the circulation flow path 660 between the distillation tank 401 and the external heat exchanger 490 to flow the liquid carbon dioxide stored in the distillation tank 401 toward the external heat exchanger 490.

The liquid carbon dioxide stored in the distillation tank 401 may be circulated through the circulation flow path using the circulation pump 450.

In addition, the distiller 400 may further include the heat dissipation fan 299 for facilitating the heat transfer to the external heat exchanger 490. A blowing fan 491 may transfer outside air toward the blowing fan 491, and transfer, through the external heat exchanger 490, heat of the outside air to the liquid carbon dioxide passing through the external heat exchanger 490. Considering the pressure of the carbon dioxide discharged from the pressure vessel, the internal temperature of the distillation tank 401 may be approximately equal to or higher than -5 ℃ and equal to or lower than 5 ℃. Accordingly, when it is assumed that a temperature of the outside air is a room temperature, heat transfer from the outside air to the liquid carbon dioxide is possible through the external heat exchanger 490.

Without separately placing the blowing fan 491, the outside air may be sucked by the heat dissipation fan 299 shown in FIG. 1 and be blowen in a direction of the external heat exchanger 490.

Eventually, the heat for the vaporization of the liquid carbon dioxide may be supplied through the external heat exchanger 490. It has an advantage of not causing the pressure drop in the distillation tank. The additional supply of the heat for the vaporization of the liquid carbon dioxide may increase the compressor flow rate by increasing the pressure of the distillation tank 401 during the regeneration process in the internal heat exchanger 410, thereby increasing the regeneration efficiency in the internal heat exchanger. This reduces the time required for the distillation operation, thereby reducing the time required for the entire washing cycle.

In addition, because the liquid carbon dioxide leaked to the external heat exchanger 490 circulates again and enters the distillation tank 401, the installation of the external heat exchanger 490 and the circulation of the liquid carbon dioxide resulted therefrom do not cause the pressure drop in the distillation tank.

As described above, the pressure vessel 200 shown in FIG. 9 is formed by the first housing 211 and the second housing 221. FIG. 9 shows an example including the separator 250 that separates the inner space of the pressure vessel 200 into the first chamber 210 and the second chamber 220.

The separator 250 may include the partition wall 251 that separates the first chamber and the second chamber from each other, and supports the driver 500 and the drum. The rotation shaft of the driver 500 may pass through the partition wall and be connected to the drum 300. By the partition wall 251, the liquid carbon dioxide exists only in the first chamber 210 and is not able to flow to the second chamber 220.

On the other hand, FIG. 10 shows the pressure vessel 200 that is not divided by the partition wall 251 and is able to accommodate the liquid carbon dioxide throughout the interior thereof as another embodiment of the pressure vessel 200. That is, when the drum 300 is inside the pressure vessel 200, the driver 500 may be located in the same space as the drum 300.

FIG. 10 shows another embodiment of supplying the heat to the liquid carbon dioxide passing through the external heat exchanger 490.

In general, the laundry treating apparatus 1000 using the carbon dioxide as the washing solvent may further include a chiller for pressure management of the storage tank 150. The chiller may be used to depressurize the storage tank 150 through cooling when the internal pressure of the storage tank 150 reaches a preset danger pressure.

FIG. 10 shows an embodiment in which the chiller is replaced with a heat pump 800. When replacing the chiller with the heat pump 800, the heat pump 800 may include a first heat exchanger 810 for heat exchange with the storage tank 150 to maintain the pressure of the storage tank 150 at a pressure equal to or lower than a preset reference pressure, and a second heat exchanger 830 for supplying the heat to the liquid carbon dioxide passing through the external heat exchanger 490 through heat exchange with the external heat exchanger 490.

In addition, the heat pump 800 may further include the first heat exchanger 810, a refrigerant compressor 820 that circulates and compresses the refrigerant that exchanges heat through the second heat exchanger 830, and an expander 825 that expands and cools the refrigerant whose heat is dissipated by passing through the second heat exchanger 830.

The first heat exchanger 810 may lower an ambient temperature as the low-temperature refrigerant passes therethrough. The heat pump 800 may further include a circulation fan 815 for blowing the air cooled by losing heat by the first heat exchanger toward the storage tank 150. The storage tank 150 may be located in a direction in which the air cooled by passing through the first heat exchanger 810 flows. Therefore, when the internal pressure of the storage tank 150 exceeds the preset reference pressure, the controller 900 may lower the pressure of the storage tank 150 by blowing low-temperature air to the storage tank 150 through the circulation fan 815.

The second heat exchanger 830 and the external heat exchanger 490 may form one heat transferring portion capable of transferring heat to each other. The second heat exchanger 830 may be in a form in which the external heat exchanger 490 is inserted thereinto for the heat transfer with the external heat exchanger 490. That is, the external heat exchanger 490 may be immersed in the compressed refrigerant. Alternatively, the second heat exchanger 830 may be disposed to face the external heat exchanger 490 in a form of a serpentine pipe, which is the same form as that of the external heat exchanger 490, and may exchange the heat with the external heat exchanger 490 through another material such as air or water.

The present disclosure is able to be modified and implemented in various forms, so that the scope thereof is not limited to the above-described implementations. Therefore, when the modified implementation includes the components of the claims of the present disclosure, it should be viewed as belonging to the scope of the present disclosure.

Claims

A laundry treating apparatus comprising:

a pressure vessel for accommodating carbon dioxide therein;

a storage tank for storing carbon dioxide therein, and supplying carbon dioxide to the pressure vessel, wherein at least a portion of the storage tank located above the pressure vessel; and

a distiller for vaporizing liquid carbon dioxide of carbon dioxide discharged from the pressure vessel to remove foreign substances therefrom, and then, liquefying vaporized carbon dioxide and supplying liquefied carbon dioxide to the storage tank,

wherein the distiller comprises:

a distillation tank located below the pressure vessel, and configured to store carbon dioxide discharged from the pressure vessel to remove foreign substances dissolved in carbon dioxide discharged from the pressure vessel;

a circulation flow path located outside the distillation tank, and configured to circulate liquid carbon dioxide stored in the distillation tank; and

an external heat exchanger positioned on the circulation flow path, and configured to heat liquid carbon dioxide passing through the circulation flow path using external heat.
The laundry treating apparatus of claim 1, wherein one end of the circulation flow path is connected to the distillation tank at a lower portion of the distillation tank such that liquid carbon dioxide stored in the distillation tank flows into the circulation flow path.
The laundry treating apparatus of claim 2, wherein the distiller further includes a circulation pump located on the circulation flow path between the distillation tank and the external heat exchanger and flowing liquid carbon dioxide stored in the distillation tank toward the external heat exchanger.
The laundry treating apparatus of claim 3, wherein the circulation flow path further includes:

a first circulation pipe for connecting the distillation tank and the external heat exchanger to each other to flow liquid carbon dioxide stored in the distillation tank to the external heat exchanger; and

a second circulation pipe for flowing carbon dioxide that has passed through the external heat exchanger to the distillation tank.
The laundry treating apparatus of claim 4, wherein the second circulation pipe is connected to the distillation tank at an upper portion of the distillation tank.
The laundry treating apparatus of claim 4, further comprising a discharge pipe for connecting the pressure vessel and the distillation tank to each other to discharge carbon dioxide from the pressure vessel to the distillation tank,

wherein the second circulation pipe is connected to the discharge pipe to flow carbon dioxide that has passed through the external heat exchanger to the distillation tank through the discharge pipe.
The laundry treating apparatus of claim 6, wherein the discharge pipe is connected to the distillation tank at an upper portion of the distillation tank.
The laundry treating apparatus of claim 1, wherein the distiller further comprises:

a distillation compressor located outside the distillation tank, sucking gaseous carbon dioxide from the distillation tank, and compressing sucked gaseous carbon dioxide;

an internal heat exchanger located inside the distillation tank and connected to the distillation compressor to perform heat exchange of compressed gaseous carbon dioxide with liquid carbon dioxide stored inside the distillation tank; and

a storage pipe for connecting the internal heat exchanger and the storage tank to each other to flow carbon dioxide cooled while passing through the internal heat exchanger to the storage tank.
The laundry treating apparatus of claim 8, wherein the distiller further comprises:

a suction pipe for connecting the distillation tank and the distillation compressor to each other to flow gaseous carbon dioxide from the distillation tank to the distillation compressor; and

a discharge pipe for connecting the distillation compressor and the internal heat exchanger to each other to flow compressed gaseous carbon dioxide to the internal heat exchanger.
The laundry treating apparatus of claim 9, wherein the internal heat exchanger is located at a lower portion inside the distillation tank.
The laundry treating apparatus of claim 10, wherein the suction pipe is connected to the distillation tank at an upper portion of the distillation tank.
The laundry treating apparatus of claim 1, further comprising a blowing fan for sucking air and supplying air,

wherein heat is supplied to liquid carbon dioxide passing through the external heat exchanger using heat of air sucked by the blowing fan.
The laundry treating apparatus of claim 1, further comprising:

a cabinet including the pressure vessel, the storage tank, and the distiller therein,

wherein the storage tank and the distillation tank are disposed closer to the other side surface than to one side surface of left and right side surfaces of the cabinet.
The laundry treating apparatus of claim 1, further comprising:

a first heat exchanger for heat exchange with the storage tank to maintain a pressure of the storage tank at a pressure equal to or lower than a preset reference pressure;

a second heat exchanger for supplying heat to liquid carbon dioxide passing through the external heat exchanger through heat exchange with the external heat exchanger; and

a refrigerant compressor for compressing a refrigerant circulating through the first heat exchanger and the second heat exchanger.
The laundry treating apparatus of claim 14, further comprising:

a circulation fan for cooling outside air through the first heat exchanger and then flowing outside air to the storage tank to cool the storage tank using outside air cooled by the first heat exchanger.