Clothes dryer

Abstract

Provided is a clothes dryer capable of drying an object to be dried through dielectric heating. The clothes dryer comprises: a cabinet; a drum rotatably provided inside the cabinet; a plurality of electrodes disposed between the cabinet and the drum; an RF power supply part for applying a voltage to the plurality of electrodes so as to generate an electric field for dielectric heating of an object to be dried accommodated in the drum; and an electrically floating lifter made of a metal material which is provided inside the drum so as to be rotatable with the drum, the lifter comprising a first part that contacts the drum and a second part that is bent from the first part and faces the inside of the drum.

Description

dryer

[0001] The present invention relates to a dryer. More specifically, it relates to a dryer capable of drying an object through dielectric heating.

[0002] A dryer is a device that dries laundry using high-temperature, dry air. A dryer dries items by slowly rotating a drum containing the items and allowing hot air to pass through the drum.

[0003] The dryer includes a cabinet forming an exterior, a drum rotatably installed inside the cabinet, a driving device for driving the drum, and a hot air supply unit for supplying hot air into the inside of the rotating drum.

[0004] When the dryer is operated after the material to be dried is placed inside the drum, the drum rotates due to the operation of the driving device, and hot air is supplied to the drum through the hot air supply unit, thereby drying the material to be dried inside the drum.

[0005] This method of drying by rotating drums has the problem of causing damage to laundry, such as wear and shrinkage, and research is currently being conducted on drying laundry while reducing damage to the laundry.

[0006] One aspect of the present disclosure provides a dryer capable of uniformly drying a drying target object through genetic heating.

[0007] One aspect of the present disclosure provides a dryer capable of reducing variation in electrostatic capacity of an electrode due to rotation of a drying material inside a drum.

[0008] One aspect of the present disclosure provides a dryer having a lifter electrically floating within a drum.

[0009] One aspect of the present disclosure provides a dryer capable of improving electrostatic capacity through a floating lifter inside a drum.

[0010] The technical problems to be achieved in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0011] A dryer according to the invention comprises: a cabinet; a drum rotatably provided inside the cabinet; a plurality of electrodes arranged between the cabinet and the drum; an RF power supply unit that applies voltage to the plurality of electrodes so as to generate an electric field for dielectric heating of an object to be dried accommodated in the drum; and a lifter made of an electrically floating metal material that is rotatably provided inside the drum together with the drum, wherein the lifter includes a first portion that contacts the drum and a second portion that is bent from the first portion and faces the inside of the drum.

[0012] A dryer according to the invention comprises a cabinet, a drum rotatably provided inside the cabinet, a plurality of electrodes spaced apart from each other along the outer circumference of the drum between the cabinet and the drum, an RF power supply unit for applying voltage to the plurality of electrodes so as to generate an electric field for dielectric heating of an object to be dried accommodated in the drum, a DC power supply unit for supplying direct current to the RF power supply unit, and a lifter rotatably provided inside the drum together with the drum, wherein the lifter comprises a lifter made of a floating metal material that is not electrically connected.

[0013] Figure 1 is a perspective view showing a dryer according to one embodiment;

[0014] Figure 2 is a cross-sectional view of the dryer shown in Figure 1;

[0015] Figure 3 is a schematic diagram showing an electrode and a lifter according to one embodiment;

[0016] Fig. 4 is a perspective view showing a lifter according to one embodiment;

[0017] Fig. 5 is a cross-sectional view schematically showing the electrodes and the lifter mounted on the drum shown in Fig. 3;

[0018] Fig. 6 is an enlarged view of part A of Fig. 5, showing a lifter according to one embodiment.

[0019] Figure 7 is a control block diagram of a dryer according to one embodiment;

[0020] Figures 8 and 9 are drawings showing changes in electrostatic capacitance according to lifter rotation depending on the number of lifters according to one embodiment.

[0021] Figure 10 is a drawing schematically showing the arrangement structure of electrodes according to one embodiment;

[0022] It should be understood that the various embodiments and terms used in this document are not intended to limit the technical features described in this document to specific embodiments, but rather to include various modifications, equivalents, or substitutes of the embodiments.

[0023] In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

[0024] The singular form of a noun corresponding to an item may include one or more of said items, unless the relevant context clearly indicates otherwise.

[0025] In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof.

[0026] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

[0027] When a component (e.g., a first component) is referred to as being "coupled" or "connected" to another component (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0028] The terms "include" or "have" are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in this document, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0029] When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

[0030] When we say that a component is "on" another component, this includes not only cases where the component is in contact with the other component, but also cases where there is another component between the two components.

[0031] The term “and / or” includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0032] Washing machines according to various embodiments may include a housing that accommodates various components therein. The housing may be provided in the form of a box with a laundry inlet formed on one side.

[0033] Below, a dryer according to various embodiments is specifically described with reference to the attached drawings.

[0034] FIG. 1 is a perspective view showing a dryer according to one embodiment, and FIG. 2 is a cross-sectional view of the dryer shown in FIG. 1.

[0035] As shown in FIGS. 1 and 2, the dryer (1) may include a cabinet (1a) forming an exterior and a drum (20) rotatably installed within the cabinet (1a).

[0036] The cabinet (1a) may be provided in a roughly hexahedral shape. The cabinet (1a) may include a top cover (1b) forming an upper surface, a front cover (1c) forming a front surface, and a base (1d) forming a bottom surface.

[0037] The front cover (1c), top cover (1b), and base (1d) forming the cabinet (1a) may be prepared separately and assembled. As another example, some components forming the cabinet (1a) (e.g., front cover, top cover, and base) may be formed integrally.

[0038] On the front of the cabinet (1a), an inlet (31) is provided for loading or unloading clothing (not shown), which is a drying object, into or out of the drum (20).

[0039] The dryer (1) may include a door (50) configured to open and close an inlet (31) formed on a front cover (1c). A user may open the door (50) and then load or discharge an object to be dried into or out of the drum (20) through the inlet (31). When the inlet (31) is closed and the dryer (1) begins operating, a door lock may lock the door (50).

[0040] A user interface (10) for interaction between a user and the dryer (1) may be provided on the upper front side of the cabinet (1a). The user interface (10) may obtain user input and display various information regarding the dryer (1).

[0041] The location of the user interface (10) is not limited to the front. The user interface (10) may be provided at various locations of the dryer (1).

[0042] The user interface (10) may include a display. Furthermore, the user interface (10) may include an input unit for obtaining user input regarding the operation of the dryer (1). The input unit may include a rotatable dial and various buttons. Additionally, the user interface (10) may include various types of input units and displays.

[0043] The display may be provided in the form of various display panels. For example, the display may include a liquid crystal display panel (LCD panel), a light emitting diode panel (LED panel), an organic light emitting diode panel (OLED panel), or a micro LED panel. The display may also be used as an input device, including a touch screen.

[0044] The display can display user-entered information or information provided to the user on various screens. The display can display information related to the operation of the dryer (1) in the form of at least an image or text. In addition, the display can display a graphical user interface (GUI) that enables control of the dryer (1). That is, the display can display UI elements (User Interface Elements), such as icons.

[0045] The input unit can transmit an electrical signal (voltage or current) corresponding to a user input to the control unit (200). The input unit can include various buttons and / or dials. For example, the input unit can include at least one of a power button for turning the dryer (1) on or off, a start / stop button for starting or stopping the drying operation, a drying course button for selecting a drying course, a temperature button for setting the drying temperature, and a time button for setting the drying time. The various buttons can be provided as physical buttons or touch buttons.

[0046] The dial included in the input unit may be configured to be rotatable. UI elements displayed on the display may move sequentially as the dial rotates. The dryer (1) may perform drying according to a selected drying course. The drying course may include drying parameters such as drying temperature and drying time. Different drying courses may be selected depending on the location of the object to be dried within the drum (20), the type of the object to be dried, and / or the amount of the object to be dried.

[0047] The dryer (1) may include a filter (40) detachably mounted on the front cover (1c). The filter (40) may filter out foreign substances such as lint that flow together with the air circulating inside the drum (20).

[0048] A cylindrical drum (20) may be provided inside the cabinet (1a). The drum (20) is provided to accommodate a drying object therein so that drying can be performed. The drum (20) may be provided to be rotatable by receiving power from a motor (72). The drum (20) may be provided inside the cabinet (1a) so as to be rotatable around a rotating axis that is provided approximately horizontally with respect to the ground.

[0049] A lifter (100) may be provided on the inner surface of the drum (20) to lift the object to be dried when the drum (20) rotates. Depending on the rotation speed of the drum (20), the object to be dried may be repeatedly raised and lowered by the lifter (100). A detailed description of the lifter (100) will be provided later.

[0050] A roller (22) may be provided on the outer surface of the drum (20) to support the drum (20) so that it rotates smoothly.

[0051] The driving device may be placed on the inner lower part of the cabinet (1a). The driving device may be mounted on the base (1d). The driving device may include a motor (72), a pulley (74) and a belt (75) for transmitting the power of the motor (72) to the drum (20).

[0052] A pulley (74) can be connected to a rotary shaft (73) connected to a motor (72). When the rotary shaft (73) is rotated by the motor (72), the pulley (74) can rotate together with the rotary shaft (73). A belt (75) can be installed so as to be wound around the outer surface of the pulley (74) and the outer surface of the drum (20). When the belt (75) is rotated by the driving force of the motor (72), the drum (20) can rotate together with the belt (75). The drum (20) can rotate clockwise or counterclockwise.

[0053] A passage (80) for circulating air may be formed inside the cabinet (1a) and inside the drum (20). The passage (80) may include an air exhaust passage (81) for discharging air from inside the drum (20) to outside the drum (20), and an air supply passage (82) for supplying air to inside the drum (20).

[0054] The dryer (1) may include an exhaust duct (60) forming an air exhaust path (81). A filter (40) may be arranged at an inlet (61) of the exhaust duct (60). The exhaust duct (60) may pass through the cabinet (1a), and an outlet (63) of the exhaust duct (60) may be exposed to the outside of the cabinet (1a). Air flowing into the inlet (61) of the exhaust duct (60) may be filtered while passing through the filter (40). The filter (40) may filter out foreign substances such as lint contained in the air.

[0055] A fan (71) for circulating air may be provided inside the cabinet (1a). By the rotation of the fan (71), air inside the drum (20) may be introduced into the exhaust duct (60). In addition, by the rotation of the fan (71), air may be supplied into the drum (20) through the air supply path (83) and the air inlet (20b) of the drum (20). The air supplied into the drum (20) may be used for drying the object to be dried.

[0056] The motor (72) can rotate not only the drum (20) but also the fan (71). Although the drum (20) and the fan (71) are exemplified as being driven by a single motor (72), this is not limited thereto. A separate fan motor (not shown) may be provided to drive the fan (71). In addition, the motor (72) may be directly connected to the drum (20) to rotate the drum (20). If the motor (72) is directly connected to the drum (20), the pulley (74) and the belt (75) may be omitted.

[0057] A plurality of electrodes may be provided between the cabinet (1a) and the drum (20). In Fig. 2, two electrodes (90, 90a, 90b) are illustrated. The electrodes (90a, 90b) may be spaced apart from each other along the periphery of the drum (20). The electrodes (90a, 90b) may also be spaced apart from the cabinet (1a) and the drum (20). When voltage is applied to the electrodes (90a, 90b), an electric field is generated inside the drum (20).

[0058] The electric field generated inside the drum (20) can vibrate the dielectric (e.g., water molecules) included in the object to be dried. When the dielectric (e.g., water molecules) vibrates, dipole frictional heat is generated, which can heat the dielectric. The heated dielectric can evaporate, thereby drying the object to be dried. The evaporated dielectric can be discharged to the outside of the drum (20) together with the air supplied into the inside of the drum (20). In the present embodiment, the electrode (90) is illustrated as two electrodes, but is not limited thereto. For example, the electrodes are spaced apart from each other along the periphery of the drum, and can divide the cylindrical drum (20) into two, three, six, twelve, or eighteen sections. The electrodes and the lifter are described in more detail below with reference to FIGS. 3 and 4.

[0059] FIG. 3 is a schematic drawing showing an electrode and a lifter according to one embodiment, FIG. 4 is a perspective view showing a lifter according to one embodiment, FIG. 5 is a cross-sectional view schematically showing the electrode and the lifter mounted on the drum shown in FIG. 3, and FIG. 6 is an enlarged view of part A of FIG. 5, showing a lifter according to one embodiment.

[0060] As illustrated in FIGS. 3 to 6, a plurality of electrodes (90) may be spaced apart from each other along the periphery of the drum (20). Each of the plurality of electrodes (90) may be provided in the shape of a plate having a curvature.

[0061] A plurality of electrodes (90) may be arranged such that two electrodes (90a, 90b) face each other along the periphery of the drum (20). The plurality of electrodes (90) may be arranged at regular intervals. The plurality of electrodes (90) are electrically connected to an RF power supply unit (220) outside the drum (20). The plurality of electrodes (90) may be provided as fixed electrodes.

[0062] A plurality of electrodes (90) may be provided as a first electrode (90) and a second electrode (90). The first electrode (90a) may be arranged on the upper side of the drum (20), and the second electrode (90b) may be arranged on the lower side of the drum (20) adjacent to the first electrode. The first electrode (90) and the second electrode (90) may have a first gap (G1) therebetween. The first gap (G1) may be provided between the first electrode (90) and the second electrode (90).

[0063] A plurality of electrodes (90) can be fixed between the cabinet (1a) and the drum (20). Since the drum (20) is not connected to the plurality of electrodes (90), the plurality of electrodes (90) do not restrict the rotation of the drum (20). In addition, since the plurality of electrodes (90) are arranged along the circumference of the drum (20), an electric field can be generated in various areas within the drum (20). Therefore, the disclosed dryer (1) can generate an electric field within the drum (20) through the plurality of electrodes (90) even while the drum (20) rotates, and can perform drying of the object to be dried.

[0064] On the other hand, since the prior art placed electrodes within the drum or electrically connected the drum (20) and the electrodes using wiring, the rotation of the drum (20) was restricted so that the connection between the drum (20) and the electrodes was not broken. In addition, since the prior art generated an electric field only in a fixed area within the drum (20), drying by dielectric heating could not occur when the object to be dried moved outside the electric field.

[0065] The dryer (1) of the present embodiment can be provided with an electrically floating lifter (100) inside the drum (20). The lifter (100) can be provided to increase the electrostatic capacity of the electrode (90) and reduce the electrostatic capacity fluctuation due to the tumble operation of the drying object inside the drum (20). The lifter (100) is provided to increase the electrostatic capacity of a plurality of electrodes (90). The lifter (100) is provided to minimize the electrostatic capacity fluctuation rate due to the behavior of the drying object inside the drum (20).

[0066] The lifter (100) may be provided to form an electric field inside the drum (20). The lifter (100) may be provided to implement the shape of an electrode inside the drum (20). The lifter (100) may be provided to implement the characteristics of an electric field inside the drum (20).

[0067] The lifter (100) may be electrically floated within the drum (20). The lifter (100) may be made of a floating metal material that is not electrically connected within the drum (20). The lifter (100) may be electrically floated. The lifter (100) may be made of a metal that is not circuit-connected. The lifter (100) may have unspecified characteristics. The lifter (100) may include a conductive metal. The lifter (100) may be a metal that is not wired. The lifter (100) may be made of a floating potential.

[0068] The lifter (100) is electrically provided in a floating state inside the drum (20), and a plurality of electrodes (90) are provided electrically connected to the RF circuit () outside the drum (20).

[0069] The lifter (100) may not have a specific electrode because it is electrically floating inside the drum (20). The lifter (100) is electrically floating inside the drum (20) so as to minimize the rate of change in electrostatic capacity according to the movement of the object to be dried inside the drum (20). The lifter (100) may be symmetrically provided inside the drum (20) relative to a plurality of electrodes (90) outside the drum (20). The lifter (100) is provided so as to function as a capacitor inside the drum (20). The lifter (100) can lower the impedance inside the drum (20), thereby assisting the driving circuit.

[0070] Electrode impedance can vary depending on various factors such as the amount of the drying object, the type of the drying object, the size of the drying object, the amount of water contained in the drying object, and the distribution state of the drying object.

[0071] The lifter (100) can replace the impedance of the drying object rotating inside the drum (20). The lifter (100) is provided with a floating metal material inside the drum (20) so that the impedance can be maintained constant. The lifter (100) can keep the impedance of the drying object rotating inside the drum (20) constant. The lifter (100) minimizes the variation in the capacitance value of the drying object rotating inside the drum (20) so that the impedance can be maintained constant. For example, when the permittivity of air inside the drum is 1, water is 80, and the drying object wet with water can be 80 or more. The capacitance fluctuates according to the rotation of the drying object. The lifter (100) installed inside the drum (20) can replace the variation in capacitance due to the rotation of the drum. Accordingly, the lifter (100) is provided to reduce the rate of change in electrostatic capacity according to the behavior of the drying target inside the drum (20) and to increase the absolute size so as to reduce the burden on the driving circuit, i.e., the matching circuit.

[0072] The lifter (100) may be a rotating structure inside the drum (20) that can improve the characteristics of increasing the capacitance of a plurality of fixed electrodes (90) and reducing the fluctuation value of the capacitance.

[0073] The lifter (100) may include a first part (110) attached to the inner surface of the drum (20), and a second part (120) bent from the first part (110) and provided to face the inner surface of the drum (20). The lifter (100) may include a shape bent in an approximately “L” shape. One side of the lifter (100) may be attached to and in contact with the inner surface of the drum (20), and the other side may be provided to protrude into the interior of the drum (20) and perform the role of a lifter that controls the rotation and / or dropping behavior of an object to be dried in the dryer.

[0074] The lifter (100) may be fixed to the drum (20). At least a portion of the lifter (100) may be provided to be attached to the inner surface of the drum (20). The lifter (100) may be fixed to the drum (20) by means of adhesives, welding, or a separate member such as a screw.

[0075] A plurality of lifters (100) may be provided inside the drum (20). The plurality of lifters (100) may be arranged at regular intervals inside the drum (20). The plurality of lifters (100) may be arranged at regular intervals inside the drum (20). The plurality of lifters (100) may be arranged at regular intervals inside the drum (20). The plurality of lifters (100) may be arranged at regular intervals inside the drum (20). In the present embodiment, 18 lifters are arranged at regular intervals, but the present invention is not limited thereto. The number of lifters may vary.

[0076] The first part (110) of the lifter (100) can be fixed to the inner surface of the drum (20). The first part (110) of the lifter (100) can be arranged to come into contact with the inner surface of the drum (20). The first part (110) can be attached to the inner surface of the drum (20). The first part (110) can be installed to the inner surface of the drum (20) by bonding, welding, or using a separate member.

[0077] The first part (110) of the lifter (100) may be formed in a roughly rectangular plate shape. The first part (110) may be formed with a first depth (d2) corresponding to the first depth (d1) of the drum (20). The first part (110) of the lifter (100) may have a first length (L1). The first length (L1) of the first part (110) may be formed to be shorter than the first gap (G1) between the plurality of electrodes (90).

[0078] The first length (L1) of the first part (110) is formed shorter than the first gap (G1) between the plurality of electrodes (90) so that the first part (110) of the lifter (100) can be positioned in the first gap (G1) between the electrodes (90) when the drum (20) rotates. Since the first length (L1) of the first part (110) is formed shorter than the first gap (G1), the first part (110) of the lifter (100) can always be positioned within the first gap (G1) so that the fluctuation value can have a uniform characteristic.

[0079] When the first length (L1) of the first part (110) of the lifter (100) is formed long, the first part (110) of the lifter (100) may or may not be positioned in the first gap (G1) between the electrodes, and thus may have an inconsistent fluctuation value.

[0080] The second part (120) of the lifter (100) may be formed by bending from the first part (110). The second part (120) may be formed by extending integrally from the first part (110). The second part (120) may have a second length (L2).

[0081] The second length (L2) of the second portion (120) may be set to a length that does not affect the behavior of the drying object inside the drum (20). The second length (L2) may be set to about 10% of the diameter of the drum (20).

[0082] A first angle (θ1) may be formed between the first part (110) and the second part (120) of the lifter (100). The first angle (θ1) may be set to be approximately 90 degrees or more. The first angle (θ1) may be formed to be greater than the vertical angle with respect to the inner surface of the drum (20).

[0083] The lifter (100) is configured such that when the first angle (θ1) increases, the second part (120) of the lifter (100) covers the first gap (G1), thereby increasing the electrode capacity of the external electrode (90) and reducing the fluctuation amount. For example, the second part (120) of the lifter (100) may overlap the adjacent first part (110) according to the first angle (θ1) to cover the first gap (G1).

[0084] The second part (120) of the lifter (100) can cover the first gap (G1) between the plurality of electrodes (90) to increase the electrostatic capacitance of the electrodes (90) and also maximize the effect of reducing the amount of fluctuation.

[0085] Fig. 7 is a control block diagram of a dryer according to one embodiment. Hereinafter, descriptions of parts overlapping with the above description are omitted.

[0086] As illustrated in FIG. 7, the dryer (1) may include a motor (72) that rotates a drum (20) and a fan (71), an RF power supply unit (220) that applies voltage to a plurality of electrodes (90) arranged around the drum (20), and a control unit (200) that controls the RF power supply unit (220) so that an electric field for dielectric heating of a drying object accommodated in the drum (20) is generated through the plurality of electrodes (90).

[0087] The dryer (1) may include a user interface (10), a DC power supply (230), and a matching circuit (210).

[0088] The control unit (200) can be electrically connected to components of the dryer (1). The control unit (200) is provided to control components of the dryer (1). For example, the control unit (200) can control a motor (72) to rotate a drum (20) and a fan (71).

[0089] The control unit (200) can control the DC power supply unit (230), the RF power supply unit (220), and the matching circuit (210) to apply voltage to a plurality of electrodes (90).

[0090] The user interface (10) is provided to obtain user input. The user interface (10) can display various information regarding the operation of the dryer (1). The user interface (10) can include an input unit for obtaining user input and a display for displaying information.

[0091] The DC power supply unit (230) can convert AC power supplied from a commercial power source (S) into DC power and transmit it to the RF power supply unit (220). The RF power supply unit (220) can generate an RF signal and apply the RF signal to a plurality of electrodes (90).

[0092] A matching circuit (210) may be provided between an RF power supply unit (220) and a plurality of electrodes (90). An RF signal generated by the RF power supply unit (220) may be transmitted to the electrodes (90) through the matching circuit (210). A sinusoidal voltage may be applied to the electrodes (90) by the RF signal.

[0093] The control unit (200) can control the DC power supply unit (230) to adjust the magnitude of the voltage applied to the electrode (90). When the power supplied to the RF power supply unit (220) increases, the amplitude of the RF signal increases, and the magnitude of the voltage applied to the electrode (90) can increase. The magnitude of the voltage can be expressed as an effective value. The control unit (200) can control the RF power supply unit (220) to adjust the phase of the voltage applied to the electrode (90). The control unit (200) can control the DC power supply unit (230) to supply power to the electronic components of the dryer (1).

[0094] The matching circuit (210) can match the output impedance of the RF power supply unit (220) and the electrode impedance of each of the plurality of electrodes (90). The matching circuit (210) can include a variable inductor and a variable capacitor. If there is a difference between the output impedance of the RF power supply unit (220) and the electrode impedance of the electrode (90), reflected power is generated from the electrode (90), and power transmission efficiency is reduced. In order to minimize the reflected power, matching of the output impedance of the RF power supply unit (220) and the electrode impedance of the electrode (90) needs to be performed. The control unit (200) can control the matching circuit (210) to perform impedance matching.

[0095] Electrode impedance can vary depending on various factors such as the amount of the drying object, the type of the drying object, the size of the drying object, the amount of water contained in the drying object, and the distribution state of the drying object.

[0096] For example, if a dielectric having a high permittivity (e.g., water) exists between a plurality of electrodes (90), the intensity of the electric field formed between the electrodes (90) may decrease because charges accumulate in the dielectric. As the intensity of the electric field decreases, the magnitude of the voltage detected at the electrodes (90) may decrease, and the electrode impedance may decrease. As the drying of the object to be dried progresses, water contained in the object to be dried is removed, and thus the electrode impedance may be detected to gradually increase.

[0097] The control unit (200) can determine the electrode impedance based on the magnitude of the voltage detected at the output terminal of the matching circuit (210). The control unit (200) can obtain distribution information of the object to be dried using the electrode impedance of each of the plurality of electrodes (90). In addition, the control unit (200) can determine the amount of water (i.e., moisture content) contained in the object to be dried based on the detected electrode impedance. The electrode impedance detected at each of the plurality of electrodes (90) may differ depending on the location of the object to be dried within the drum (20).

[0098] In addition, when the drum (20) rotates while the drying target is contained inside the drum (20), the drying target may be clumped or dispersed, and the electrode impedance detected by each of the plurality of electrodes (90) may be different depending on the distribution state of the drying target.

[0099] When an electrically floating lifter (100) is provided inside a drum (20), the control unit (200) can obtain information on the electrode impedance of the lifter (100). The floating lifter (100) that is not electrically connected inside the drum (20) has a constant electrode impedance, and thus can minimize the rate of change in electrostatic capacity according to the behavior of the object to be dried inside the drum (20).

[0100] The control unit (200) can adjust the rotation speed of the drum (20) to compensate for the increase in the friction coefficient of the inner wall of the drum (20) according to the number of lifters (100). When the drum (20) of the dryer (1) rotates, the main movement of the object to be dried inside is "peak-fall" along the wall of the drum (20). At this time, the movement characteristics (Froude Number) of the object to be dried have various influencing factors. Among them, the higher the friction coefficient, the better it can move along the inside of the drum (20). When the number of lifters (100) of the drum (20) is increased, the friction coefficient increases, so the control unit (200) can reduce the rotation speed (rpm) of the drum (20) to maintain the friction coefficient.

[0101] The control unit (200) controls the rotation direction of the drum (20) to be opposite to the bending direction of the second part (120) of the lifter (100), i.e., the direction in which the internal drying object falls when the drum (20) rotates, thereby reducing the surface friction coefficient and preventing the friction coefficient from increasing.

[0102] Figures 8 and 9 are diagrams showing changes in electrostatic capacitance according to lifter rotation depending on the number of lifters according to one embodiment. Hereinafter, descriptions of parts overlapping with the above description are omitted.

[0103] As illustrated in FIGS. 8 and 9, the lifter (100) can reduce the rate of change in electrostatic capacity according to the movement of the drying object inside the drum (20). When the number of lifters (100) increases, the change in electrostatic capacity according to the rotation of the lifter (100) can be observed. When the number of lifters (100) increases, the change in electrostatic capacity according to the rotation of the lifter (100) can be reduced.

[0104] For example, three (a), eight (b), twelve (c), and eighteen (d) lifters (100) can be installed on the drum (20). When the lifters (100) rotate at 0 degrees, 10 degrees, 20 degrees, and 30 degrees according to the rotation of the drum (20), the change in electrostatic capacitance (C value) can be measured to determine the change in electrostatic capacitance.

[0105] First, when three (a) lifters (100) are installed, it can be seen that the electrostatic capacitance (C value) increases from 2.8 to 3.0, 4.5, and 7 pF when the lifters (100) are at 0 degrees, 10 degrees, and 20 degrees. When three (a) lifters (100) are installed, the variation value of the electrostatic capacitance is 311.6%.

[0106] In addition, when eight lifters (100) are installed (b), it can be seen that the electrostatic capacitance (C value) increases from 3.3 to 4.3 and then decreases from 3.9 to 3.2 pF when the lifters (100) are 0 degrees, 10 degrees, and 20 degrees. When eight lifters (100) are installed (b), the variation value of the electrostatic capacitance is 43.9%.

[0107] When 12(c) lifters (100) are installed, it can be seen that the electrostatic capacitance (C value) increases from 2.9 to 3.1 and then decreases from 3.0 to 2.9 pF when the lifters (100) are 0 degrees, 10 degrees, 20 degrees, and 30 degrees. When 12(c) lifters (100) are installed, the variation value of the electrostatic capacitance is 14.4%.

[0108] When 18 (d) lifters (100) are installed, it can be seen that the electrostatic capacitance (C value) decreases from 3.1 to 3.0 and is maintained between 3.1 and 3.0 when the lifters (100) are 0 degrees, 10 degrees, 20 degrees, and 30 degrees. When 18 (d) lifters (100) are installed, the variation value of the electrostatic capacitance is 2.96%. That is, when there are 3 (a) lifters (100), the variation value of the electrostatic capacitance is 311.6%, when there are 8 (b) lifters, the variation value of the electrostatic capacitance is 43.9%, when there are 12 (c) lifters, the variation value of the electrostatic capacitance is 14.4%, and when 18 (d) lifters are installed, the variation value of the electrostatic capacitance is 2.96%.

[0109] As described above, it can be seen that the more lifters (100) installed inside the drum (10), the less the change in electrostatic capacitance. When the number of lifters (100) increases, the change in electrostatic capacitance due to the rotation of the lifters (100) can be reduced.

[0110] As disclosed in one embodiment, the number of lifters (100) is not limited to 18. The number of lifters (100) may vary depending on the number of electrodes.

[0111] Fig. 10 is a drawing schematically showing the arrangement structure of electrodes according to one embodiment. Hereinafter, descriptions of parts overlapping with the above description are omitted.

[0112] As illustrated in FIG. 10, three electrodes (90a, 90b, 90c) may be spaced apart and adjacent to each other along the periphery of the drum (20). The first electrode (90a) may be positioned on the upper right side of the drum (20), the second electrode (90b) may be positioned below the drum (20) adjacent to the first electrode, and the third electrode (90c) may be positioned on the upper left side of the drum (20) adjacent to the first electrode. The number of electrodes is not limited to those illustrated. The number of electrodes may vary.

[0113] A floating lifter (100) that is not electrically connected may be provided inside the drum (20). The lifter (100) may be arranged at a predetermined interval inside the drum (20). The lifter (100) may include a first part (110) mounted inside the drum (20) and a second part (120) that is bent at a first angle (θ1) from the first part (110). The lifter (100) may be provided to reduce the rate of change in electrostatic capacity according to the behavior of the object to be dried inside the drum (20) and to increase the absolute size, thereby reducing the burden on the driving circuit, i.e., the matching circuit.

[0114] According to the idea of ​​the present disclosure, by attaching a floating lifter (100) to the inner wall of a drum (20), which is a rotating body, the electrostatic capacitance of the electrode (90) can be increased, and the electrostatic capacitance fluctuation due to the rotation of the dry material inside the drum (20) can be reduced, thereby increasing the efficiency of the dryer (1).

[0115] According to one embodiment, a dryer (1) comprises: a cabinet (1a); a drum (20) rotatably provided inside the cabinet (1a); a plurality of electrodes (90) arranged between the cabinet (1a) and the drum (20); an RF power supply unit (220) that applies voltage to the plurality of electrodes (90) so as to generate an electric field for dielectric heating of an object to be dried accommodated in the drum (20); and a lifter (100) made of a metal material that is rotatably provided inside the drum (20) together with the drum (20) and is electrically floating, wherein the lifter (100) includes a first portion (110) that contacts the drum (20) and a second portion (120) that is bent from the first portion (110) and faces the inside of the drum (20). According to the present disclosure, it is possible to reduce a change in electrostatic capacity due to rotation of an object to be dried inside the drum by the lifter. In addition, it is possible to increase the efficiency of the dryer by increasing the electrostatic capacity of the electrodes.

[0116] The plurality of electrodes include a first gap (G1) between adjacent electrodes, and a first length (L1) of the first portion is shorter than the first gap (G1). At least one of the lifters overlaps the first gap.

[0117] The above lifters are provided in multiple units and are arranged at regular intervals in the circumferential direction inside the drum. The second length (L2) of the second part is formed smaller than the radius of the drum. A first angle (θ1) between the drum and the second part is formed to be 90 degrees or more. The plurality of electrodes are arranged spaced apart along the outer circumference of the drum. A DC power supply unit for supplying direct current power to the RF power supply unit is included. The lifters are fixed to the drum by at least one of adhesive, welding, or screws. The plurality of lifters include a second gap (G2) between adjacent lifters, and when the first angle (θ1) increases, the second part covers the second gap (G2).

[0118] These lifters can reduce the fluctuation of electrostatic capacity due to the rotation of the dry material inside the drum.

[0119] A control unit configured to control the RF power supply unit is further included, wherein the control unit can adjust the speed (rpm) of the drum to correct an increase in the coefficient of friction of the inner wall of the drum according to the number of the lifters. The control unit can correct an increase in the coefficient of friction of the inner wall of the drum increased by the lifters by adjusting the rotational direction of the drum to be opposite to the bending direction of the second part. By making the bending direction of the second part of the lifter opposite to the rotational direction of the drum, the surface friction coefficient of the building material inside the drum can be reduced.

[0120] According to one embodiment, a dryer includes: a cabinet; a drum rotatably provided inside the cabinet; a plurality of electrodes spaced apart from each other along an outer circumference of the drum between the cabinet and the drum; an RF power supply unit that applies voltage to the plurality of electrodes so as to generate an electric field for dielectric heating of an object to be dried contained in the drum; a DC power supply unit that supplies direct current to the RF power supply unit; and a lifter rotatably provided inside the drum together with the drum, the lifter being a floating metal material that is not electrically connected. According to the present disclosure, a change in electrostatic capacity due to rotation of an object to be dried inside the drum can be reduced by the lifter. In addition, the efficiency of the dryer can be increased by increasing the electrostatic capacity of the electrodes.

[0121] The lifter includes a first portion that contacts the drum and a second portion that is bent from the first portion and faces the inside of the drum. The plurality of electrodes include a first gap (G1) between adjacent electrodes, and a first length (L1) of the first portion is shorter than the first gap (G1). The lifter is provided in plurality and is arranged at a constant interval in the circumferential direction inside the drum. A second length (L2) of the second portion is formed to be smaller than a radius of the drum. A first angle (θ1) between the drum and the second portion is formed to be 90 degrees or more. The plurality of lifters have a second gap (G2) between adjacent lifters, and when the first angle (θ1) increases, the second portion covers the second gap (G2). Such a lifter can reduce a change in electrostatic capacity due to rotation of a building material inside the drum. The capacitance fluctuation rate of the electrode due to the rotation of the lifter according to the tumble behavior of the drum can be minimized.

[0122] It further includes a control unit configured to control the RF power supply unit, wherein the control unit can determine the rotation speed of the drum.

[0123] For example, a drying target can be uniformly dried through genetic heating.

[0124] For example, the capacitance of electrodes arranged circumferentially on the outside of the drum (external electrodes) can be increased.

[0125] For example, it is possible to reduce the variation in electrostatic capacity due to rotation of the internal structure of the drum.

[0126] For example, the electrostatic capacity can be improved through a lifter inside the drum.

[0127] For example, the efficiency of the dryer can be increased by increasing the electrostatic capacitance of the electrode.

[0128] For example, when a dry object having a dielectric constant undergoes a tumble operation, the capacitance fluctuation rate of an external electrode can be reduced and the load fluctuation rate can be reduced.

[0129] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0130] In describing the dryer with reference to the attached drawings above, specific shapes and directions have been mainly described, but it should be understood that various modifications and changes can be made by those skilled in the art, and such modifications and changes should be interpreted as being included within the scope of the disclosed invention.

Claims

1. Cabinet; A drum rotatably provided inside the above cabinet; A plurality of electrodes arranged between the cabinet and the drum; An RF power supply unit that applies voltage to the plurality of electrodes to generate an electric field for dielectric heating of a drying target accommodated in the drum; and A dryer comprising a lifter made of an electrically floating metal material, which is rotatable together with the drum within the drum, the lifter comprising a first part contacting the drum, and a second part bent from the first part and directed toward the inside of the drum.

2. In paragraph 1, The above plurality of electrodes include a first gap between adjacent electrodes, A dryer in which the first length of the first part is set shorter than the first gap.

3. In paragraph 2, The above first gap is A dryer in which at least one of the above lifters is overlapped.

4. In paragraph 1, The above lifters are provided in multiples, A dryer arranged at regular intervals in a circumferential direction inside the drum.

5. In paragraph 1, The second length of the above second part is, A dryer formed to a radius smaller than that of the drum.

6. In paragraph 5, A dryer wherein the first angle between the drum and the second part is formed at 90 degrees or more.

7. In paragraph 1, A dryer wherein the plurality of electrodes are spaced apart along the outer periphery of the drum.

8. In paragraph 1, A dryer including a DC power supply unit for supplying direct current power to the RF power supply unit.

9. In paragraph 1, A dryer wherein the lifter is secured to the drum by at least one of adhesive, welding or screw methods.

10. In paragraph 6, The above plurality of lifters have a second gap between adjacent lifters, A dryer in which the second portion covers the second gap when the first angle increases.

11. In paragraph 1, Further comprising a control unit configured to control the RF power supply unit; The above control unit, A dryer that adjusts the speed of the drum to compensate for an increase in the friction coefficient of the inner wall of the drum according to the number of lifters.

12. In paragraph 11, The above control unit, A dryer that compensates for an increase in the coefficient of friction of the inner wall of the drum caused by the lifter by adjusting the rotation direction of the drum in the opposite direction to the bending direction of the second part.

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