Patent Application
20250198077
The invention relates to methods of heating and drying an object by application of radio frequency field (radio frequency drying), and more specifically, to radio frequency drying device and method. The invention can be used in radio frequency dryers.
A dryer is an electronic device that dries the laundry with heat or air. The dryer may heat air by using a heater. The dryer may dry the laundry by having the heated air pass a drum having the laundry put therein. The dryer may spin the drum so that the laundry is evenly dried on the whole. The dryer is widely used because it is able to dry the laundry quickly in humid weather.
Aspects of embodiments of the disclosure will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.
According to an embodiment of the disclosure, a radio frequency (RF) drying device is provided. In an embodiment, the RF drying device includes a drying chamber including a grounded body enclosing N (N≥3) electrodes for generating radio frequency field, and a drum electrically insulated from the N electrodes. In an embodiment, the RF drying device a processor configured to select and activate M (<N) electrodes among the N electrodes and deactivate one or more remaining (N−M) electrodes periodically in an active mode. In an embodiment, a group of M electrodes has a symmetry plane passing through a central axis of the drying chamber which vertically passes through a center of the drying chamber. In an embodiment, the processor is configured to select M electrodes for being activated to generate AC signals and deactivate N-M electrodes for being deactivated not to generate AC signals in the active mode, and to supply AC signals to the activated M electrodes. In an embodiment, an RF field is formed inside the drying chamber based on the generated AC signals.
According to an embodiment of the disclosure, a radio frequency (RF) drying device includes a drying chamber unit having a central axis and including a grounded body, a plurality of N electrodes to generate radio frequency fields, where N≥3, and the plurality of N electrodes are enclosed by the grounded body, and a drying objects housing that is surrounded by the plurality of N electrodes, and is electrically insulated from the plurality of N electrodes; an AC signal configuration block to configure an AC signal for each electrode of the plurality of N electrodes; a matching unit to match, for each electrode of the plurality of N electrodes, an electrode load impedance with a respective output impedance of the AC signal configuration block; and a controller. Each electrode of the plurality of N electrodes has a same shape, and faces the central axis, the electrodes of the plurality of N electrodes are substantially evenly spaced around the drying objects housing and around the central axis, the electrodes of the plurality of N electrodes are arranged such that any two adjacent electrodes of the plurality of N electrodes have a symmetry plane passing through the central axis, and about which the plurality of N electrodes are symmetrically arranged, and each electrode of the plurality of N electrodes is electrically coupled to the AC signal configuration block via the matching unit. The controller is configured to control the AC signal configuration block to perform an inactive operation mode in which each electrode of the plurality of N electrodes is in an inactive electrode state, and control the AC signal configuration block to perform a plurality of active operation modes, wherein each active operation mode of the plurality of active operation modes is a mode in which a group of M electrodes of the plurality of N electrodes is in an active electrode state, and remaining electrodes of the plurality of N electrodes are in the inactive electrode state, wherein M is a positive even integer, M<N, and the group of M electrodes has a respective symmetry plane passing through the central axis and dividing the electrodes of the group of M electrodes into M/2 symmetrical pairs of electrodes, wherein the electrodes of the group of M electrodes on a first side of the respective symmetry plane are supplied with a first AC signal, and the electrodes of the group of M electrodes on a second side of the respective symmetry plane are supplied with a second AC signal, the first AC signal and the second AC signal being antiphase signals.
According to an embodiment of the disclosure, the inactive electrode state may be a state in which no AC signal or a low-level AC signal is supplied to an electrode of the plurality of N electrodes.
According to an embodiment of the disclosure, the low-level AC signal may be a signal with a voltage not exceeding 1/10 of a voltage of the signal supplied to an electrode of the plurality of N electrodes in the active electrode state.
According to an embodiment of the disclosure, the matching unit may include N matching sensors configured to determine a matching level of the electrode load impedance with a respective output impedance of the AC signal configuration block for each electrode of the plurality of N electrodes, and is connected to the controller to transfer values of the N matching sensors. The controller may be configured to control a power level supplied to the electrodes of the plurality of N electrodes by the AC signal configuration block, and execute a cyclic drying process, wherein each active operation mode of the plurality of active operation modes is processed in each cycle. When performing an active operation mode of the plurality of active operation modes, the controller may be configured to perform impedance matching of the electrode load impedance with the respective output impedance of the AC signal configuration block for the active operation mode of the plurality of active operation modes during a first time period, determine the matching level of the M electrodes in the active electrode state for the active operation mode of the plurality of active operation modes based on the values of the N matching sensors, and, if the determined matching level of the M electrodes in the active electrode state for the active operation mode of the plurality of active operation modes does not exceed a predetermined matching threshold, perform the inactive operation mode for a first time period, or, if the determined matching level of the M electrodes in the active electrode state for the active operation mode of the plurality of active operation modes is equal to or greater than the predetermined matching threshold, perform a heating procedure for a second time period. The second time period may be greater than the first time period. The power level supplied to the M electrodes in the active electrode state during the matching procedure may be less than the power level supplied to the M electrodes in the active electrode state during the heating procedure.
According to an embodiment of the disclosure, provided is a method of radio frequency (RF) drying, performed by a radio frequency drying device that includes a drying chamber unit having a central axis and including a drying objects housing that is surrounded by, and electrically insulated from, a plurality of N electrodes to generate radio frequency fields, where N≥3, wherein each electrode of the plurality of N electrodes has a same shape, and faces the central axis of the drying chamber unit, the electrodes of the plurality of N electrodes are substantially evenly spaced around the drying objects housing and around the central axis, and the electrodes of the plurality of N electrodes are arranged such that any two adjacent electrodes of the plurality of N electrodes have a symmetry plane passing through the central axis, and about which the plurality of N electrodes are symmetrically arranged, the method including placing an object to be dried into the drying objects housing; performing a drying process by alternating a plurality of operation modes including an inactive operation mode and a plurality of active operation modes, wherein the inactive operation mode is an operation mode of the plurality of operation modes in which each electrode of the plurality of N electrodes is in an inactive electrode state, each active operation mode of the plurality of active operation modes is a mode in which a group of M electrodes of the plurality of N electrodes is in an active electrode state, and remaining electrodes of the plurality of N electrodes are in the inactive electrode state, wherein M is a positive even integer, M<N, and the group of M electrodes has a respective symmetry plane passing through the central axis and dividing the electrodes of the group of M electrodes into M/2 symmetrical pairs of electrodes, wherein the electrodes of the group of M electrodes on a first side of the respective symmetry plane are supplied with a first AC signal, and the electrodes of the group of M electrodes on a second side of the respective symmetry plane are supplied with a second AC signal, the first AC signal and the second AC signal being antiphase signals; and performing impedance matching for each of the electrodes of the group of M electrodes.
According to an embodiment of the disclosure, the inactive electrode state may be a state in which no AC signal or a low-level AC signal is supplied to an electrode of the plurality of N electrodes.
According to an embodiment of the disclosure, the low-level AC signal may be a signal with a voltage not exceeding 1/10 of a voltage of the signal supplied to an electrode of the plurality of N electrodes in the active electrode state.
According to an embodiment of the disclosure, the performing of the drying process by alternating multiple operation modes may include performing a cyclic process by performing, in each cycle, each active operation mode of the plurality of active operation modes. The performing of the plurality of active operation modes may include performing the impedance matching for the active operation mode of the plurality of active operation modes during a first time period, determining a matching level of the M electrodes in the active electrode sate for the active operation mode of the plurality of active operation modes, and, if the determined matching level of the M electrodes in the active electrode state for the active operation mode of the plurality of active operation modes does not exceed a predetermined matching threshold, performing the inactive operation mode for a first time period, or, if the determined matching level of the M electrodes in the active electrode state for the active operation mode of the plurality of active operation modes is equal to or greater than the predetermined matching threshold, performing a heating procedure for a second time period. The second time period may be greater than the first time period, and a power level supplied to the M electrodes in the active electrode state during the matching procedure may be less than the power level supplied to the M electrodes in the active electrode state during the heating procedure.
An example embodiment of the disclosure provides a high uniformity and efficiency of the drying process.
An embodiment of the disclosure will be set forth in part in the description which follows and, in part, will be apparent from the disclosure.
These and/or other embodiments of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
An embodiment of the disclosure and terms as used therein is not intended to limit the technical features described in the disclosure to a specific embodiment and should be understood as including various modifications, equivalents, or alternatives of the embodiment.
In connection with the description of the drawings, like reference numbers may be used to denote like or related elements.
A singular form of a noun corresponding to an item may include one or more items, unless the relevant context clearly indicates otherwise.
In the disclosure, the expressions “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 in the corresponding expression or all possible combinations thereof.
The term “and/or” as used herein includes a combination of a plurality of related recited elements or any one of a plurality of related recited elements.
The terms “first,” “second,” etc. as used herein may be only used to distinguish one element from another and do not limit the elements in any other aspects (e.g., importance or order).
When a certain (e.g., first) element is referred to as being “coupled” or “connected” to another (e.g., second) element with or without the terms “functionally” or “communicatively,” it means that the certain element may be coupled or connected to the other element directly (e.g., by wire) or wirelessly or through a third element.
The terms “comprise” or “include” as used herein are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.
It will be understood that when an element is referred to as being “connected to,” “coupled to,” “supported to,” or “in contact with” another element, the element may be “directly connected to, coupled to, supported to, or in contact with” the other element or may be “indirectly connected to, coupled to, supported to, or in contact with” the other element through a third element.
It will be understood that when an element is referred to as being located “on” another element, the element may be in contact with the other element, and another element may also be present between the two elements.
Hereinafter, an embodiment of the disclosure will be described in detail with reference to the accompanying drawings, so that those of ordinary skill in the art may easily carry out the disclosure. However, the disclosure may be implemented in various different forms and is not limited to the embodiment described herein. In order to clearly explain an embodiment of the disclosure, parts irrelevant to the description are omitted in the drawings, and the same or similar reference numerals are assigned to the same or similar parts throughout the disclosure.
Hot air is used to dry objects. However, hot air drying of objects, e.g., clothing, can lead to undesirable effects (deformation, damage, etc.). Partly, this is due to the fact that heat is transferred to the object basically by heat transfer on the contact surface between hot air and the object. In addition, hot air dryers (tumble dryers) are typically noisy and require powerful means for cooling and/or heat distribution (e.g., a fan to distribute warm air throughout the drying chamber).
A wet object (containing some water) has dielectric properties sufficient to dissipate radio frequency energy and heat the water inside. Applying a radio frequency field (electromagnetic field (EM) in the radio frequency range) to a wet object provides drying the object at a low temperature. The radio frequency drying ensures high penetration of EM field into the clothing (radio frequency field acts throughout the moisture volume) resulting in more uniform heating in the radio frequency field application areas. However, there is a problem of nonuniform distribution of radio frequency field within the drying space (e.g., in the drying chamber), therefore, the drying efficiency depends on the object position in the drying space. The problem of uniformity of radio frequency field distribution can be mitigated by providing movement of the object relative to the EM field, for example, using a moving drying chamber, but this makes relatively silent operation of the drying device infeasible due to the need of electric motors to provide movement of the drying chamber. In addition, radio frequency dryers suffer from a safety problem related to possible radio frequency leakage.
RF dryers provides high penetration into the clothing for heating. However, there is a problem of drying uniformity because drying depends on the geometry of object.
According to an embodiment of the disclosure, a method and apparatus is provided for drying a wet textile article with a radio frequency (RF) applicator and a processor. The method includes energizing the RF applicator to generate a field of electromagnetic radiation (e-field). The method further includes determining a dynamic drying cycle of operation in the processor. The method further includes controlling the energization of the RF applicator according to the determination of the dynamic drying cycle of operation. The wet article is dried. The method may have the problem related to position and geometry of the object to be dried.
According to an embodiment of the disclosure, a laundry drying RF applicator may be provided. The RF applicator is only an exemplary structure for generating EM field. The issue related to the position and geometry of the object to be dried may be remained.
A drying device may include a drum indented to form multiple notches. An arcuate electrode is positioned within each notch. A source of radio frequency power, operating at a single fixed frequency, is coupled to each electrode. This disclosure provides a special electrode structure and a method of non-contact energy supply to the electrodes. However, neither the problem related to position and geometry of the object to be dried, nor the protection against radio frequency leakage are addressed.
The drying device 1 may include a drying chamber 2, a processor 5, a motor 120, a heating module 130, an air blowing module 140, a sensor 150, a filter 160, and a door 170.
According to an embodiment of the disclosure, the drying chamber 2 may be rotationally arranged in the body of the drying device 1. The drying chamber 2 may be shaped like a pillar. For example, the drying chamber 2 may have the form of a cylinder. The drying chamber 2 may be arranged to face a side of the drying device 1. For example, one of the upper side and the lower side of the drying chamber 2 may be arranged to face the door 170 of the drying device 1 and the other may be arranged to face an inner side of the drying device 1. The drying chamber 2 may be arranged such that one of the upper and lower sides is open and the open side faces the door 170. The drying chamber 2 may receive the laundry through the open side. The drying chamber 2 may evenly mix the laundry while spinning.
According to an embodiment of the disclosure, the motor 120 may rotate the drying chamber 2. The motor 120 may provide rotational force to the drying chamber 2. When a current is applied to the motor 120, the motor 120 may rotate around an axis or shaft. The axis or shaft of the motor 120 may be coupled to a belt 121. The belt 121 may be wound around the drying chamber 2. When the motor 120 rotates, the belt 121 may rotate the drying chamber 2 while moving in one direction. In an embodiment of the disclosure, the motor 120 may rotate the drying chamber 2 directly through a shaft. In such a case, the belt 121 may not be required to transfer the rotating force from the motor 120 to the drying chamber 2.
According to an embodiment of the disclosure, the heating module 130 may heat the air in the drying device 1. For example, the heating module 130 may heat the surrounding air. The heating module 130 may be arranged outside the drying chamber 2. For example, the heating module 130 may be arranged under the drying chamber 2 and at a distance from an outer side of the drying chamber 2.
According to an embodiment of the disclosure, the air blowing module 140 may be arranged to be adjacent to the heating module 130. For example, the air blowing module 140 may be arranged to be adjacent to one side of the heating module 130. The air blowing module 140 may include a fan. The air blowing module 140 may force the air in the drying device 1 heated by the heating module 130 to flow into the drying chamber 2. For example, the air blowing module 140 may force the air heated by the heating module 130 to flow into the drying chamber 2 through a first path 191.
According to an embodiment of the disclosure, the filter 160 may be arranged between the drying chamber 2 and the door 170. The filter 160 may have a separable and installable structure. The filter 160 may filter out foreign substances included in the air. The filter 160 may capture the foreign substances such as dust and lint contained in the air coming out from the drying chamber 2 through a second path 192. The filter 160 may have a structure that is able to capture the foreign substances. For example, the filter 160 may have a mesh structure.
According to an embodiment of the disclosure, the sensor 150 may be arranged to be adjacent to the filter 160. For example, the sensor 150 may be arranged to be adjacent to the top of the filter 160. The sensor 150 may detect whether the filter 160 is installed. For example, the sensor 150 may distinguish between a case that the filter 160 is separated from the drying device 1 and a case that the filter 160 is installed in the drying device 1. The sensor 150 may generate a detection signal based on whether the filter 160 is installed. The sensor 150 may send the generated detection signal to the at least one processor 5.
According to an embodiment of the disclosure, the at least one processor 5 may control overall operation of the drying device 1. The at least one processor 5 may include a central processing unit (CPU), an application processor (AP), a graphic processing unit (GPU), and an artificial intelligence (AI) processor. The AI processor may be manufactured in the form of a dedicated hardware chip, or manufactured as part of a CPU, an AP or a graphic-dedicated processor and installed in the drying device 1. The AI processor may be designed in a hardware structure specialized in processing an AI model. The AI processor may generate an AI model through learning. For example, the AI processor may generate an AI model having predefined operation rules established to perform a desired feature (or an object) by being trained with a lot of training data according to a learning algorithm. The at least one processor 5 may receive the detection signal from the sensor 150. The at least one processor 5 may determine whether the filter 160 is installed in the drying device 1 based on the detection signal. For example, the at least one processor 5 may determine whether the filter 160 is separated from the drying device 1 based on the detection signal. For example, the at least one processor 5 may determine whether the filter 100 is reinstalled in the dryer 160 based on the detection signal.
The drying chamber 2 may include a grounded body 6 enclosing a set of three electrodes, including a first electrode 7, a second electrode 8, and a third electrode 9. The three electrodes may have or may not have the same shape. A drying objects housing 10 is arranged between the electrodes. A central axis (not shown) passes inside the drying space in the central part. I.e., the central axis vertically passes through the center of the drying chamber. Drying space refers herein to the space for objects (laundry) to be dried inside the drying objects housing 10. The drying objects housing 10, the electrodes 7 to 9, and the grounded body 6 are arranged substantially around the central axis in the sequence shown in
According to an embodiment of the disclosure, electrodes 7 to 9 may be of the same shape, evenly spaced around the central axis (i.e., at equal angular distance from each other) and at the same distance relative to the central axis. Herein, the recitation of “at the same distance from the central axis” means that some center points of the electrodes are at the substantially same distance from the central axis, i.e., on a circle lying in a plane perpendicular to the central axis, with the center lying on the central axis with a reasonable margin of error. Each electrode is symmetrical with respect to the symmetry plane passing through the central axis and center of the electrode. In other words, each electrode has symmetry with respect to the symmetry plane and is oriented so that the symmetry plane passes through said central axis. More specifically, each electrode is facing the central axis. Each pair of adjacent electrodes has symmetry (i.e., are substantially symmetrical) with respect to a plane passing between these electrodes through the central axis. In this design, the set of three electrodes as a whole has three symmetry planes of the electrodes.
It should be noted that, as may be assumed from
The electrodes are made of a conductive material and may have any suitable design according to the features described herein. Each of the three electrodes 7 to 9 is separately connected to the AC signal configuration block 4 via the matching unit 3 as shown in
The drying objects housing 10 forms a space for placing the objects to be dried (drying space), which is electrically insulated from the electrodes and other components of the drying device.
It is contemplated that the drying objects housing 10 may be made of a dielectric material that provides insulation and transmits radio frequency radiation from the electrodes, such as plastic. However, the drying objects housing 10 may be made of, for example, metal materials, if, for example, this is justified for increasing the housing structure strength with a negligible effect on the propagation of radio frequency radiation inside the drying objects housing 10. The drying objects housing 10 may be a thin-walled drum made of plastic. It is contemplated that the drying objects housing 10 has at least one opening for loading the objects to be dried, which can be closed by a lid to prevent foreign objects from entering the drying objects housing 10 (in other words, a drying space) during drying. The housing may not be leak-proof and has some elements (e.g., holes) for active (e.g., by fans that may be provided in the drying device 1) or passive (i.e., for active or passive ventilation) removal of moisture evaporated from the objects being dried.
Referring to
According to an embodiment of the disclosure, the disclosure provides for a more uniform drying in the drying space (i.e., more uniform application of the radio frequency field in the drying space). According to an embodiment, the disclosure may provide for a more uniform drying in the drying space without moving parts, in particular without a movable drying objects housing, but this is not a limitation. According to an embodiment, the drying objects housing 10 may be movable. For example, the drying objects housing 10 may be an electrically driven movable drum that rotates around the central axis during the drying process. According to an embodiment, the drying device 1 can further enhance the uniformity of the radio frequency field application and, therefore, the uniformity of drying the objects.
The grounded body 6 is made of a conductive material, e.g., metal, and surrounds the drying objects housing 10 and electrodes 7 to 9. The grounded body 6 acts as a barrier to limit the propagation of the radio frequency field generated by the electrodes 7 to 9 during the drying process and ensure electromagnetic safety in the areas around the drying device 1.
The AC signal configuration block 4 is configured to configure AC signals for each of the electrodes 7 to 9 to enable the drying device 1 at least to operate in any of four operation modes described below.
In the exemplary embodiment shown in
According to an embodiment of the disclosure, the AC source 17 generates initial AC signal of a given frequency and sends it to the power divider 16. The power divider 16 divides the initial signal into three initially identical signals, one of which is fed (see
Depending on the state of the one-bit (i.e., having two possible states) control signal arrived at the phase shifter input, each of the two one-bit controlled phase shifters 14 and 15 either does not affect the phase of the incoming signal, resulting in an in-phase signal generated at the phase shifter output, or reverses the signal phase, i.e., rotates the phase by 180 degrees, this resulting in an antiphase signal at the phase shifter output relative to the input signal. As shown in
The first, second, and third power amplifiers 11 to 13 send AC signals to the first, second, and third electrodes 7 to 9, respectively, via the matching unit 3. As stated above, the power amplifiers 11 to 13 are controllable. The power amplifiers are controlled by the processor 5. In an embodiment, the power amplifiers 11 to 13 can set, by the processor 5, at least two states: 1) state of maximum power (i.e., amplitude of the output signal) and 2) state of minimum power, which may also be referred to as inactive state or inactive electrode state. Discrete and/or smooth variable control of each power amplifier via the processor 5 over the entire range from minimum to maximum output power may not be excluded.
Minimum power state or inactive electrode state is hereafter referred to as the processor 5 controlled state of the power amplifier corresponding to the electrode, in which the power output signal coming from the power amplifier to the electrode is zero (i.e., there is substantially no signal), is a minimum power possible for this power amplifier or a power significantly lower than the maximum possible power for the amplifier (e.g., lower than 10% of the maximum power). Accordingly, active electrode state refers herein to the state opposite of the inactive electrode state.
The above exemplary configuration of the AC signal configuration block 4 in an exemplary embodiment shown in
As mentioned above, each of the three electrodes 7 to 9 is separately coupled to the AC signal configuration block 4 via the matching unit 3. The matching unit 3 provides matching, separately for each of the electrodes 7 to 9, between a power supply in the form of an AC signal configuration block 4 and a respective load in the form of the electrode. The power supply may provide power to the drying device 1. This matching is known as “source and load matching”, “impedance matching”, “matching complex impedances of high-frequency signal source and load”, “matching the input impedance level”, etc. In an embodiment of
The matching element unit 19 includes three controllable (tunable or switchable) matching elements (not shown in
Referring to
According to an embodiment of the disclosure, while the first electrode 7 is in active state, the processor 5 continuously monitors values of the matching sensor 22, performs necessary calculations with the values of the matching sensor 22, and generates, based on the monitored values of the matching sensor 22 and the calculation, a control signal for the matching element 21 to adjust parameters of a oscillating circuit (LC circuit) of the matching element 21 to ensure matching between the first power amplifier 11 and the respective load in the form of the first electrode 7, i.e. to ensure that load impedance Zload of the first electrode 7 is matched with output impedance Zs of the first electrode 7. According to an embodiment, the processor 5 may match the load impedance Zload of the first electrode 7 with output impedance Zs of the first electrode 7 at a high level which exceeds a predetermined matching level. The predetermined matching level indicates a certain level accepted as “high level matching” between match the load impedance Zload of the first electrode 7 with output impedance Zs of the first electrode 7.
The above matching is necessary because the electrode load impedance (for each electrode) varies responsive to the position of the object being dried in the drying space, and responsive to the current humidity, i.e., the amount of moisture, of the object. High matching level indicates that most of the radio frequency radiation generated by the electrode is absorbed by moisture, i.e., operation of the electrode in question is generally effective. Conversely, low matching indicates that a small part of the radio frequency radiation generated by the electrode is absorbed by moisture, i.e. operation of the electrode in question is inefficient, since most of the radio frequency radiation, and, accordingly, energy, returns to the electrode. Low electrode matching at high power can cause components of the drying device 1 to overheat and fail. The matching unit 3 is designed to ensure maximum possible matching under given conditions, i.e., current humidity and position of the objects being dried in the drying space, in other words, current amount and distribution of radio frequency absorbing moisture in the drying space.
According to an embodiment of the disclosure, based on of the matching sensor 22 value, as the amount of moisture decreases and thus the matching level is achieved, the processor 5 may, by controlling the first power amplifier 11 (as shown in
According to an embodiment of the disclosure, in the initial period after the electrode has switched to active state (e.g., at the beginning of one of the respective active operation modes described below), the processor 5 may, by controlling the first power amplifier 11, set a low power to be supplied to the first electrode 7, e.g., a minimum power of the active electrode state. And then, the processor 5 may, continuously during the matching process, or once after the maximum matching level has been reached, based on the matching level achieved, e.g., a higher or maximum safe (for the matching level), set power to be supplied to the electrode. Such control of the power supplied to the electrode by the processor 5 in the initial period may be conventionally referred to as a test mode or matching procedure, in which, after the drying process has started, a small amount of power is first supplied to the electrodes, at least until the highest possible matching has been achieved. Thereby overheating and failure of the drying device 1 components is avoided, which can occur when operating at high or maximum power with a low matching level.
The matching element 21 is controllable, and the matching element 21 may include an oscillating circuit (LC circuit). The oscillating circuit may include one or more controllable (switchable and/or tunable) elements. Thus, a control signal to control the matching element 21 may be, e.g., a set of one or more logic and/or analog signals (e.g., voltage signals) controlling respective controlled elements, this is not limited hereto. As an example,
Referring to
Referring to
As matching and control of the power supplied to the first electrode 7 according to the diagram shown in
In an exemplary embodiment shown in
In an embodiment of
One of the four operation modes, hereinafter referred to as the inactive operation mode, is an operation mode in which all the electrodes, i.e., all the three electrodes 7 to 9, are deactivated (or in inactive state). The inactive operation mode may also be referred to as an inactive mode and the active operation mode may also be referred to as an active mode. As shown in
The remaining three of the four operation modes are active operation modes. In each of the active operation modes, a unique pair of three electrodes is in active state, and the remaining electrode is in inactive state. The unique pair of electrodes receives antiphase signals by the control of the processor 5. “Unique pair of three electrodes” here means that there are no two active operation modes in which the same pair of three electrodes is in active state. Although operations modes are divided into four (4) different modes, the number of different modes may be varied according to the number of electrodes used for generating radio frequency. In addition, the processor 5 may select the unique pair of three electrodes entering the active state and the inactive state, respectively. The processor 5 may select the unique pair of three electrodes for being activated (entering the active state) in a temporal manner. The selection of the unique pair of three electrodes in the temporal manner will be described referring to Table 1 below.
According to an embodiment of the disclosure, referring to
Table 1 below summarizes each of the four operation modes.
The drying device 1 according to an embodiment shown in
According to the structure and arrangement of the electrodes described above, any pair of adjacent electrodes has a symmetry plane passing between them through the central axis, i.e., any two adjacent electrodes are substantially identical in shape and symmetrically positioned relative to each other. In operation of the drying device 1 shown in
It should be noted that the design of the AC signal configuration block 4 controlled by the processor 5, shown in
As described above, the processor 5 may control the AC signal configuration block 4 to provide operation in four modes. Meanwhile, at each instance in operation (during the drying process), the drying device 1 is in one of the four operation modes. As mentioned above, in inactive mode, no power is substantially supplied to the electrodes, and no radio frequency field is generated. In each active operation mode, a radio frequency field is formed in a respective area (located substantially between the electrodes in that particular mode in the active state) of the drying space. During the drying process, the processor controls these four operation modes according to a predefined program to ensure optimal drying process.
The aforementioned control of modes or performance of modes herein refers to selection of sequence of the modes, selection of duration of the modes, selection of parameters for the modes (including setting parameters, such as power supplied to electrodes, for each mode and/or varying the parameters during the mode). The disclosure is not limited to a particular method of controlling the performance of modes. It should be noted that the mode performance is controlled such that to additionally ensure even more uniform drying by adapting the drying process to current conditions, which may change over time. The current conditions may include, but not limited to, the number and distribution of the objects being dried and thus the moisture, temperature of the objects, current temperature and humidity of air in the drying objects housing 10, the weight of the objects, etc.
In an embodiment, the processor 5 may control the modes based on the values received from the matching sensor unit 20. For example, for any active operation modes in which the matching level achieved is low (e.g., below a predetermined minimum matching level), the processor 5 may perform at least one of the steps: the step of excluding the time period of the active operation mode from the drying process (in other words, excluding active operation mode from the drying process), the step of replacing the time period of the active operation mode with the period of inactive operation mode (in other words, replacing active operation mode with inactive operation mode), the step of reducing power supplied to the electrodes, and the step of reducing duration of active operation mode. The drying process may include a repetitive process of performing the active operation mode and the inactive operation mode.
According to an embodiment of the disclosure, in the drying process, the processor 5 may control the AC signal configuration block 4 to manage the modes to provide cyclic operation, where in each cycle each of the four modes is performed sequentially for a predetermined time. Use of three active operation modes in total ensures a relatively uniform application of the radio frequency field in the drying space, and performance of inactive operation mode can give additional time for heat redistribution in the moisture and objects dried, thereby preventing local overheating and damage of the objects dried. Such control of the modes ensures a more uniform drying. As a non-limiting example, in each cycle, the duration of inactive operation mode can be equal to the sum of durations of active operation modes.
According to an embodiment of the disclosure, during the drying process, the processor 5 may control the AC signal configuration block 4 to manage cyclic performance of the operation modes, in which all active operation modes are sequentially performed in each cycle, alternating with inactive operation mode. That is, a cycle sequentially performs, for example, first active operation mode, inactive operation mode, second active operation mode, inactive operation mode, third active operation mode, inactive operation mode, then the cycle begins again. That is, each active operation mode is followed by inactive mode. As a non-limiting example, periods of performing all modes can be equal in each cycle. Such control of the modes provides the effects identical to those for the mode control described above. According to an embodiment of the disclosure, the duration of the inactive mode and the duration of the following (or preceding) active mode may differ from each other. For example, the first active mode may last for 10 seconds—the inactive mode for 7 seconds—the second active mode for 10 seconds—the inactive mode for 7 seconds—the third active mode for 10 seconds—the inactive mode for 7 seconds.
In addition to controlling the sequence of modes at predetermined durations, in an embodiment, the processor 5 may also control the duration of the modes. For example, based on values from the matching sensor unit 20, the processor 5 may set a shorter duration for the modes in which the achieved matching level is lower (meaning that a smaller portion of radio frequency radiation is absorbed by moisture).
According to an embodiment of the disclosure, with the drying objects housing 10 as a rotating drum, during the drying process, the processor 5 may control the AC signal configuration block 4, based on the rotational speed of the rotating drum or the angle of rotation, to manage the modes so as to synchronize the modes with the rotation angle of the rotating drum. In this case, a higher drying uniformity can be achieved. The rotation angle may be determined using, for example, a drum speed sensor (by integrating sensor values via the processor 5) and/or a drum angle sensor (not shown). In an embodiment, the modes may be controlled such that, in the operation cycle, during the first time period corresponding to predetermined first angle Δϕ1 of the drum rotation (i.e., during the first time period, the drum is rotated by angle Δϕ1), three active operation modes are performed sequentially for equal periods of time, and then, during the second time period, corresponding to the angle Δϕ2 of the drum rotation, inactive operation mode is performed.
In an embodiment, the drying device 1 may include, for example, temperature sensors and/or humidity sensors (not shown) to measure temperature and/or humidity of air in the drying space—i.e., inside the drum, respectively. The processor 5 may control the mode based on values from the temperature sensor and/or the humidity sensor. For example, based on the humidity sensor values, the processor 5 may increase the period or periods of inactive operation mode or decrease the periods of active operation mode if relative humidity of air in the drying space is 100% or exceeds a predetermined humidity threshold. The predetermined humidity threshold may be, for example, 80% humidity level. In an embodiment, based on the temperature sensor values, the processor 5 may increase period or periods of inactive operation mode or reduce periods of active operation if the air temperature exceeds a predetermined temperature threshold. Both exemplary embodiments may prevent overheating of the drying device 1, and/or prevent overheating of the moist air discharged from the drying device 1 during the drying process by passive or active ventilation, thereby ensuring safe use of the drying device 1. According to an embodiment of the disclosure, the processor 5 may change the time duration of the inactive operation mode and/or the active operation mode based on the temperature and/or humidity of air in the drying space.
It should be noted that the number of three electrodes, shown in an embodiment referring to
It should be noted that in an embodiment with reference to
In an embodiment of the disclosure, the active electrodes engaged in an active operation mode, lying on one side of the symmetry plane of symmetrical pairs of electrodes, do not necessarily form a continuous sequence. For example, in a drying device having six electrodes, two symmetrical pairs of electrodes may be in active state in one of the active operation mode, i.e., the first and sixth electrodes, and the third and fourth electrodes, among which the first and third electrodes, lying on one side of the symmetry plane of the symmetrical pairs of electrodes, do not form a continuous sequence, because the second electrode, being in inactive state in this active operation mode, is located between them and the fifth electrode lies on the opposite side of the symmetry plane of symmetrical pairs of electrodes.
When one or more symmetrical pairs (pairs of electrodes symmetrical with respect to the same symmetry plane passing through the central axis) are engaged in each active operation mode, with antiphase signals sent to the electrodes in each pair, higher matching, more efficient radio frequency field application, and consequently more efficient drying are ensured because the matching performed by the matching unit is simpler than matching in other way (particularly, with an odd number of electrodes, if there is no symmetry between the electrodes, if symmetrical pairs of active electrodes do not have a common symmetry plane, etc.). At the same time, the implementation of successively performed multiple modes ensures high uniformity of drying without a movable drying objects housing (e.g., a rotating drum).
The radio frequency drying described herein can implement, through the control of processor 5, an adaptive radio frequency drying process. The adaptive radio frequency drying process may be described below with reference to
In the adaptive radio frequency drying process, the processor 5 may control cyclic performance of the operation modes. In each cycle, the processor 5 may “go” through each of active operation modes and inactive operation mode, as shown in
During the drying process, the drying device 1 performs, via the controller, the following operations.
The drying device 1 may perform the first active operation mode in operation S101, the drying device 1 may perform the second active mode in operation S102, and the drying device 1 may perform the third active mode in operation S103, respectively. In these steps, all three active operation modes are performed. Operations S101-S103 form the major part of the cycle of adaptive radio frequency drying process discussed here. It should be noted that the term “perform the active mode” does not necessarily mean a “complete” execution of the active mode. As will be explained below, it may not be feasible or desirable to “completely” execute some active mode, and the processor 5 may replace the active mode with an inactive operation mode.
In operation S104, the drying device 1 may perform transition to the next cycle if drying is completed, or ending the adaptive radio frequency drying process. In operation S104, it is determined whether the drying process is finished. If the drying process is not finished, the next cycle of adaptive radio frequency drying process including the operations of S101-S103 is performed. If the drying process is finished, the adaptive radio frequency drying process is completed and the drying device 1, for example, switches to idle state according to an embodiment of the disclosure. The disclosure is not limited to a particular method of determining whether the drying process is complete. For example, the processor 5 may determine that drying is finished if, in each of the active operation modes, the matching level achieved is less than a predetermined matching threshold for a predetermined time period (meaning that there is little or no moisture in the drying space that could absorb radio frequency radiation). As another example, the processor 5 may determine that drying is finished based on the values from one or more moisture sensors, if any. In an embodiment, if the moisture sensors detect the values (moisture values) falling to a moisture threshold value of 10%, for example, the processor 5 may determine that drying is finished.
Performing each active operation mode (operations S101-S103 in
In operation S201, the drying device 1 may perform matching procedure during time Tm. At the beginning, during or just before the matching procedure, the processor 5 switches the AC signal configuration block 4 to the state corresponding to current active operation mode. The matching procedure is performed during matching time period Tm. Meanwhile, the power supplied to active electrodes is set (by setting values of signals controlling the power amplifiers) to a low value, which may be referred to as matching power level, at which, on one hand, sufficient power is provided to generate radio frequency field and perform the matching process, and on the other hand, components of the drying device 1 are not allowed to overheat at a low matching level (e.g., if there is no moisture in the exposure area of radio frequency field formed by active electrodes of this active operation mode, which could absorb the radio frequency radiation). In an embodiment of the disclosure, matching time for the matching procedure is chosen such that transient processes during the matching are likely to be completed. In other words, during the matching time, the maximum matching level is likely to be achieved. The matching time in a system may depend on frequency of AC signals, speed of the processor that controls the matching process, speed of transient processes during matching, etc. It should be noted that the matching procedure, as the initial part of active operation mode, includes substantially execution of that active operation mode at low power, at which there is little or no heating, and within a short time period during which the transition process of control performed by the matching unit will be completed.
In operation S202, the drying device 1 may determine the matching level of active electrodes. In this operation, the matching level of active electrodes for a given active operation mode (i.e., the electrodes that are in active state in this active operation mode) is determined from values of sensors of the matching sensor unit 20. It should be noted that, the matching sensor unit 20 generates signals (values) reflecting matching for each of the electrodes, required for individual matching of each electrode. Determining the matching level of active electrodes refers herein to determining a certain resulting matching level according to a given rule, reflecting the matching of electrodes as a whole for current active operation mode. As an example, matching level of active electrodes can be defined as the minimum value among matchings of active electrodes, i.e., for example, as the result of calculation of min(1/|Snn|, 1/|Smm|) or 1/max (|Snn|, |Smm|), when considering active (for the mode under analysis) electrodes n and m.
In operation S203, the drying device 1 may heat during time period Th according to operation S204, if the electrode matching level for this active operation mode is equal to or greater than a predetermined matching threshold. Otherwise, the drying device 1 may perform inactive operation mode during time period Th according to operation S205. At this operation, the processor 5 may compare the matching level of active electrodes, obtained in operation 203, with the matching threshold. If the matching level of active electrodes does not exceed the threshold value, the inactive operation mode according to operation S205 is performed during the time period Th (in other words, execution of active operation mode is replaced by execution of inactive operation mode). The fact that the matching level of active electrodes does not exceed the threshold value indicates that the use of current active mode is unreasonable because there are no wet objects to absorb radio frequency radiation in the area exposed to the active electrodes in this active operation mode.
When this active operation mode is performed “completely” (i.e., at higher power and for longer time period than at the matching procedure), the operation efficiency will be low, and the drying device 1 components may be overheated, which is undesirable. Conversely, if the electrode matching level for this active operation mode is equal to or greater than the predetermined matching threshold, the adaptive radio frequency drying process proceeds to operation S204.
In operation S204, the drying device 1 may perform heating procedure during time Th. In this operation, power supplied to the active electrodes is set to a higher (e.g., nominal) value, which may be referred to as heating power level. Heating power level is not necessarily a fixed value for a particular system. Heating power level can be selected and adjusted during the drying process by the processor 5 depending on specific drying conditions based on the sensors provided in the drying device 1, as mentioned above. In addition, the heating power level can be selected by the user of the drying device 1 when starting the drying process. According to an embodiment of the disclosure, the heating time Th may be greater than the matching time Tm. After operation S204, the active operation mode is finished. It should be noted that the heating procedure, as the major part of active operation mode, is substantially the execution of this active operation mode at a higher power (e.g., nominal power) at which heating occurs.
In operation S205, the drying device 1 may perform inactive operation mode for time Th. In this operation, the processor 5 switches the AC signal configuration block 4 of the drying device 1 to inactive operation mode for time period Th. As mentioned above, this is equivalent to replacing active operation mode (and more specifically, heating procedure of active operation mode) with inactive operation mode. The replacement of active operation mode with inactive operation mode, instead of completely skipping the active operation mode (and more specifically, heating procedure of active operation mode), “saves” time for heat redistribution in the drying space. That is, during the time of performing a particular active operation mode having a duration of Tm+Th, other drying regions covered by other partially or wholly different active operation mode will redistribute heat without heating, regardless of whether actual heating (i.e., heating procedure) is performed during the time of the particular active operation mode. Thereby, overheating of the objects being dried can be avoided. Simple skipping of the heating procedure in the absence of the required matching level in a particular active operation mode would reduce the cycle duration of the adaptive radio frequency drying process by time Th and respectively reduce the time for heat redistribution without heating for those active operation mode in which the heating procedure is still in progress, which could reduce uniformity of drying and lead to overheating of the objects being dried. After operation S205, the active operation mode is finished.
The adaptive radio frequency drying described here ensures that all active operation modes are performed successively, providing uniform drying in the drying space. Moreover, for each active operation mode, a low-power matching procedure is performed first, and it is determined whether a higher power mode should be continued (i.e., whether the heating procedure should be performed) based on the matching level achieved. Therefore, use of the drying device 1 ensures safety and high efficiency and increases uniformity of drying.
According to an embodiment of the disclosure, a radio frequency (RF) drying device is provided. In an embodiment, the RF drying device includes a drying chamber including a grounded body enclosing N (N≥3) electrodes for generating radio frequency field, and a drum electrically insulated from the N electrodes. In an embodiment, the RF drying device a processor configured to select and activate M (<N) electrodes among the N electrodes and deactivate one or more remaining (N−M) electrodes periodically in an active mode. In an embodiment, a group of M electrodes has a symmetry plane passing through a central axis of the drying chamber which vertically passes through a center of the drying chamber. In an embodiment, the processor is configured to select M electrodes for being activated to generate AC signals and deactivate N−M electrodes for being deactivated not to generate AC signals in the active mode, and to supply AC signals to the activated M electrodes. In an embodiment, an RF field is formed inside the drying chamber based on the generated AC signals.
According to an embodiment of the disclosure, the processor is configured to deactivate all the N electrodes in an inactive mode, and to perform the active mode and the inactive mode by turns.
According to an embodiment of the disclosure, N matching circuits each of which connected to each of N electrodes, respectively N matching sensors each of which connected to each of the N matching circuits, respectively. According to an embodiment of the disclosure, each of the N matching circuits includes at least one inductor and at least one capacitor.
According to an embodiment of the disclosure, the RF drying device includes N power amplifiers each of which connected to each of N matching sensors.
According to an embodiment of the disclosure, the processor is configured to match at a high level exceeding a predetermined matching level between each of the N power amplifiers and each of the N electrodes.
According to an embodiment of the disclosure, the processor is configured to generate N control signals each of which for each of the N matching circuits to adjust parameters of each of the N matching circuits for the matching between each of the N power amplifiers and each of the N electrode.
According to an embodiment of the disclosure, the processor is configured to match load impedance and and output impedance of each of the N electrodes based on each of the N control signals.
According to an embodiment of the disclosure, the processor is configured to monitor values generated from the N matching sensors and to generate the N control signals based on the values generated from the N matching sensors.
According to an embodiment of the disclosure, the processor is configured to change the selection of M electrodes for being activated among the N electrodes periodically in the active mode.
According to an embodiment of the disclosure, the processor is configured to supply a first AC signal to one or more first electrodes among the M electrodes, lying on one side of the symmetry plane and a second AC signal to one or more second electrodes among the M electrodes, lying on the other side of the symmetry plane, and the second AC signal is antiphase to the first AC signal.
According to an embodiment of the disclosure, the processor is configured to control power supplied to the N electrodes or switch the active mode to the inactive mode in response to a change of amount of moisture.
According to an embodiment of the disclosure, N is 3 and M is 2.
According to an embodiment of the disclosure, the processor is configured to activate any of two electrodes among three electrodes in the active mode including a first active mode, a second active mode and a third active mode and deactivate three electrodes in the inactive mode including a first inactive mode, a second inactive mode and a third inactive mode, and a drying process includes a repetitive process of performing the active mode and the inactive mode.
According to an embodiment of the disclosure, the processor is configured to activate first electrode and second electrode among the three electrodes in the first active mode after the first inactive mode, activate the second electrode and third electrode among the three electrodes in the second active mode after the second inactive mode, and activate the third electrode and the first electrode among the three electrodes in the third active mode after the third inactive mode, where one of the activated two electrodes receives an initial signal and the other of the activated two electrodes receives an antiphase signal to the initial signal.
According to an embodiment of the disclosure, the first inactive mode, the first active mode, the second inactive mode, the second active mode, the third inactive mode, and the third active mode are performed sequentially.
According to an embodiment of the disclosure, the time duration of the inactive mode is equal to the time duration of the active mode.
According to an embodiment of the disclosure, the processor is configured to replace any one active mode from the drying process with any one inactive mode in response to a matching level being lower than a predetermined matching level, and the matching level is a level of matching between each of N power amplifiers and each of the N electrodes.
According to an embodiment of the disclosure, the processor is configured to synchronize each of the active mode and the inactive mode with a rotation angle of the drum.
According to an embodiment of the disclosure, the RF drying device includes at least one temperature sensor configured to measure temperature inside the drum, and the processor increase a period of the inactive mode or decrease a period of the active mode in response to the temperature inside the drum exceeding a predetermined temperature threshold.
According to an embodiment of the disclosure, at least one humidity sensor is configured to measure humidity of air inside the drum, and the processor increases a period of the inactive mode or decrease a period of the active mode in response to the humidity of air inside the drum exceeding a predetermined humidity threshold.
According to an embodiment of the disclosure, each of the N electrodes is of the same shape and evenly spaced around the drum and the central axis passing inside a center of the drying chamber.
According to an embodiment of the disclosure, two adjacent electrodes of the N electrodes have a symmetry plane passing through a center axis of the drying chamber.
According to an embodiment of the disclosure, a radio frequency (RF) drying device is provided. The RF drying device includes a drying chamber unit, an AC signal configuration block, a matching unit, and a processor. According to an embodiment of the disclosure, the drying chamber unit has a central axis and includes a grounded body enclosing a plurality of N electrodes for generating radio frequency field and a drying objects housing, where N≥3, the drying objects housing being electrically insulated from the electrodes. According to an embodiment of the disclosure, electrodes of the plurality of N electrodes are of the same shape and substantially evenly spaced around the drying objects housing and around the central axis of the drying chamber unit, and are facing the central axis of the drying chamber unit, where any two adjacent electrodes of the plurality of N electrodes have a symmetry plane passing through the drying chamber central axis, the symmetry plane is also the symmetry plane for the plurality of N electrodes, each of the electrodes being electrically coupled to the AC signal configuration block via the matching unit.
According to an embodiment of the disclosure, the AC signal configuration block is configured to generate an AC signal for each of the electrodes.
According to an embodiment of the disclosure, the matching unit is configured to match, for each electrode, the electrode load impedance with respective output impedance of the AC signal configuration block.
According to an embodiment of the disclosure, the processor is configured to control the AC signal configuration block to perform inactive operation mode in which each of the N electrodes is in inactive state.
According to an embodiment of the disclosure, the processor is configured to control the AC signal configuration block to perform a plurality of active operation modes, where each active operation mode of the plurality of active operation modes is a mode where a group of M electrodes is in active state, and the remaining one or more electrodes of the plurality of N electrodes are in inactive state.
According to an embodiment of the disclosure, M is a positive even integer, M<N and a group of M electrodes has a symmetry plane passing through the central axis of the drying chamber unit and dividing the group of M electrodes into M/2 symmetrical pairs of electrodes, where the electrodes lying on one side of said symmetry plane are supplied with a first AC signal, and the electrodes lying on the other side of said symmetry plane are supplied with a second AC signal, the first AC signal and the second AC signal being antiphase signals.
According to an embodiment of the disclosure, the inactive is a state in which no AC signal or a low-level AC signal is supplied to the electrodes.
According to an embodiment of the disclosure, the low-level AC signal is a signal with a voltage not exceeding 1/10 of the voltage of the signal supplied to the electrodes in active state.
According to an embodiment of the disclosure, the matching unit includes N matching sensors configured to determine a matching level of the electrode load impedance with respective output impedance of the AC signal configuration block for each of the N electrodes. According to an embodiment of the disclosure, the matching unit is connected to the processor to transfer values of the matching sensors.
According to an embodiment of the disclosure, the processor is further configured to control a power level supplied to the electrodes by the AC signal configuration block.
According to an embodiment of the disclosure, the processor is further configured to execute a cyclic drying process, where each active operation mode of the plurality of active operation modes is processed in each cycle.
According to an embodiment of the disclosure, when performing an active operation mode from the plurality of active modes, the processor is configured to perform the matching procedure for the active operation mode during a first time period, determine the matching level of the active electrodes for the active operation mode based on the values of the matching sensors.
According to an embodiment of the disclosure, if the determined matching level of the active electrodes for the active operation mode does not exceed a predetermined matching threshold, the processor performs inactive operation mode for a first time period.
According to an embodiment of the disclosure, if the determined matching level of the active electrodes for the active operation mode is equal to or greater than a predetermine matching threshold, the processor performs a heating procedure for the active operation mode for a second time period.
According to an embodiment of the disclosure, the second time period is greater than the first time period.
According to an embodiment of the disclosure, the power level supplied to the electrodes during the matching procedure is less than the power level supplied to the electrodes during the heating procedure.
According to an embodiment of the disclosure, a method of radio frequency (RF) drying, performed by a radio frequency drying device is provided.
According to an embodiment of the disclosure, the method includes placing an object to be dried into a drying objects housing surrounded by a plurality of N electrodes for generating a radio frequency field, where N≥3, the electrodes of the plurality of N electrodes are of the same shape and substantially evenly spaced around the drying objects housing and around the central axis of the drying chamber unit, and are facing the central axis of the drying chamber unit, where any two adjacent electrodes from the plurality of N electrodes have a symmetry plane passing through the central axis of the drying chamber, the symmetry plane being also the symmetry plane for the entire plurality of N electrodes.
According to an embodiment of the disclosure, the method includes performing drying process by alternating a plurality of operation modes including inactive operation mode and multiple active operation modes.
According to an embodiment of the disclosure, the inactive operation mode is an operation mode in which each of the N electrodes is in inactive electrode state.
According to an embodiment of the disclosure, each active operation mode among the plurality of active operation modes is a mode in which a group of M electrodes is in active state and the remaining one or more electrodes of the plurality of N electrodes are in inactive state.
According to an embodiment of the disclosure, M is a positive even integer, M<N.
According to an embodiment of the disclosure, a group of M electrodes has a symmetry plane passing through the central axis of the drying chamber unit and dividing the group of M electrodes into M/2 symmetrical pairs of electrodes, the electrodes lying on one side of said symmetry plane being supplied with a first AC signal, and the electrodes lying on the other side of said symmetry plane being supplied with a second AC signal, where the first AC signal and the second AC signal are antiphase signals.
According to an embodiment of the disclosure, the method includes performing impedance matching for each electrode of the group of M electrodes.
According to an embodiment of the disclosure, the inactive state is a state in which no AC signal or a low-level AC signal is supplied to the electrode.
According to an embodiment of the disclosure, the low-level AC signal is a signal with a voltage not exceeding 1/10 of the voltage of the signal supplied to the electrodes in active state.
According to an embodiment of the disclosure, the step of performing drying process by alternating the plurality of operation modes, including inactive operation mode and a plurality of active operation modes may include performing a cyclic process by performing, in each cycle, each active mode of the plurality of active operation modes.
According to an embodiment of the disclosure, the performing of active operation modes includes performing the matching procedure for the active operation mode during a first time period and determining the matching level of active electrodes for the active operation mode.
According to an embodiment of the disclosure, if the determined matching level of the active electrodes for the active operation mode does not exceed a predetermined matching threshold, the method includes performing inactive operation mode for the first time period.
According to an embodiment of the disclosure, if the determined matching level of the active electrodes for the active operation mode is equal to or greater than a predetermined matching threshold, the method includes performing a heating procedure for the active operation mode for a second time period.
According to an embodiment of the disclosure, the second time period is greater than the first time period.
According to an embodiment of the disclosure, the power level supplied to the electrodes in the matching procedure is less than the power level supplied to the electrodes in the heating procedure.
According to an embodiment of the disclosure, a radio frequency (RF) drying device includes a drying chamber unit having a central axis and including a grounded body, a plurality of N electrodes to generate radio frequency fields, where N≥3, and the plurality of N electrodes are enclosed by the grounded body, and a drying objects housing that is surrounded by the plurality of N electrodes, and is electrically insulated from the plurality of N electrodes; an AC signal configuration block to configure an AC signal for each electrode of the plurality of N electrodes; a matching unit to match, for each electrode of the plurality of N electrodes, an electrode load impedance with a respective output impedance of the AC signal configuration block; and a processor. Each electrode of the plurality of N electrodes has a same shape, and faces the central axis, the electrodes of the plurality of N electrodes are substantially evenly spaced around the drying objects housing and around the central axis, the electrodes of the plurality of N electrodes are arranged such that any two adjacent electrodes of the plurality of N electrodes have a symmetry plane passing through the central axis, and about which the plurality of N electrodes are symmetrically arranged, and each electrode of the plurality of N electrodes is electrically coupled to the AC signal configuration block via the matching unit. The processor is configured to control the AC signal configuration block to perform an inactive operation mode in which each electrode of the plurality of N electrodes is in an inactive electrode state, and control the AC signal configuration block to perform a plurality of active operation modes, wherein each active operation mode of the plurality of active operation modes is a mode in which a group of M electrodes of the plurality of N electrodes is in an active electrode state, and remaining electrodes of the plurality of N electrodes are in the inactive electrode state, wherein M is a positive even integer, M<N, and the group of M electrodes has a respective symmetry plane passing through the central axis and dividing the electrodes of the group of M electrodes into M/2 symmetrical pairs of electrodes, wherein the electrodes of the group of M electrodes on a first side of the respective symmetry plane are supplied with a first AC signal, and the electrodes of the group of M electrodes on a second side of the respective symmetry plane are supplied with a second AC signal, the first AC signal and the second AC signal being antiphase signals.
According to an embodiment of the disclosure, the matching unit may include N matching sensors configured to determine a matching level of the electrode load impedance with a respective output impedance of the AC signal configuration block for each electrode of the plurality of N electrodes, and is connected to the processor to transfer values of the N matching sensors. The processor may be configured to control a power level supplied to the electrodes of the plurality of N electrodes by the AC signal configuration block, and execute a cyclic drying process, wherein each active operation mode of the plurality of active operation modes is processed in each cycle. When performing an active operation mode of the plurality of active operation modes, the processor may be configured to perform impedance matching of the electrode load impedance with the respective output impedance of the AC signal configuration block for the active operation mode of the plurality of active operation modes during a first time period, determine the matching level of the M electrodes in the active electrode state for the active operation mode of the plurality of active operation modes based on the values of the N matching sensors, and, if the determined matching level of the M electrodes in the active electrode state for the active operation mode of the plurality of active operation modes does not exceed a predetermined matching threshold, perform the inactive operation mode for a first time period, or, if the determined matching level of the M electrodes in the active electrode state for the active operation mode of the plurality of active operation modes is equal to or greater than the predetermined matching threshold, perform a heating procedure for a second time period. The second time period may be greater than the first time period. The power level supplied to the M electrodes in the active electrode state during the matching procedure may be less than the power level supplied to the M electrodes in the active electrode state during the heating procedure.
According to an embodiment of the disclosure, provided is a method of radio frequency (RF) drying, performed by a radio frequency drying device that includes a drying chamber unit having a central axis and including a drying objects housing that is surrounded by, and electrically insulated from, a plurality of N electrodes to generate radio frequency fields, where N≥3, wherein each electrode of the plurality of N electrodes has a same shape, and faces the central axis of the drying chamber unit, the electrodes of the plurality of N electrodes are substantially evenly spaced around the drying objects housing and around the central axis, and the electrodes of the plurality of N electrodes are arranged such that any two adjacent electrodes of the plurality of N electrodes have a symmetry plane passing through the central axis, and about which the plurality of N electrodes are symmetrically arranged, the method including placing an object to be dried into the drying objects housing; performing a drying process by alternating a plurality of operation modes including an inactive operation mode and a plurality of active operation modes, wherein the inactive operation mode is an operation mode of the plurality of operation modes in which each electrode of the plurality of N electrodes is in an inactive electrode state, each active operation mode of the plurality of active operation modes is a mode in which a group of M electrodes of the plurality of N electrodes is in an active electrode state, and remaining electrodes of the plurality of N electrodes are in the inactive electrode state, wherein M is a positive even integer, M<N, and the group of M electrodes has a respective symmetry plane passing through the central axis and dividing the electrodes of the group of M electrodes into M/2 symmetrical pairs of electrodes, wherein the electrodes of the group of M electrodes on a first side of the respective symmetry plane are supplied with a first AC signal, and the electrodes of the group of M electrodes on a second side of the respective symmetry plane are supplied with a second AC signal, the first AC signal and the second AC signal being antiphase signals; and performing impedance matching for each of the electrodes of the group of M electrodes.
According to an embodiment of the disclosure, the performing of the drying process by alternating multiple operation modes may include performing a cyclic process by performing, in each cycle, each active operation mode of the plurality of active operation modes. The performing of the plurality of active operation modes may include performing the impedance matching for the active operation mode of the plurality of active operation modes during a first time period, determining a matching level of the M electrodes in the active electrode sate for the active operation mode of the plurality of active operation modes, and, if the determined matching level of the M electrodes in the active electrode state for the active operation mode of the plurality of active operation modes does not exceed a predetermined matching threshold, performing the inactive operation mode for a first time period, or, if the determined matching level of the M electrodes in the active electrode state for the active operation mode of the plurality of active operation modes is equal to or greater than the predetermined matching threshold, performing a heating procedure for a second time period. The second time period may be greater than the first time period, and a power level supplied to the M electrodes in the active electrode state during the matching procedure may be less than the power level supplied to the M electrodes in the active electrode state during the heating procedure.
Although the disclosure describes the operation of the drying device 1 with the first electrode 7 in general, the same operations are also applicable to all of the electrodes.
An embodiment of the disclosure may also be implemented in the form of a recording medium including instructions executable by a computer, such as a program module executed by a computer. A computer-readable recording medium may be any available media that are accessible by the computer and may include any volatile and non-volatile media and any removable and non-removable media. In addition, the computer-readable recording medium may include a computer storage medium and a communication medium. The computer-readable storage medium may include any volatile, non-volatile, removable, and non-removable media that are implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules, or other data. The communication medium may typically include computer-readable instructions, data structures, program modules, other data of a modulated data signal, such as carriers, or other transmission mechanisms, and may include any information delivery medium. In addition, the disclosure may be implemented as a computer program or a computer program product, which includes instructions executable by a computer, such as a computer program executed by a computer.
A machine-readable storage medium may be provided in the form of a non-transitory storage medium. The non-transitory storage medium is a tangible device and only means not including a signal (e.g., electromagnetic wave). This term does not distinguish between a case where data is semi-permanently stored in a storage medium and a case where data is temporarily stored in a storage medium. For example, the non-transitory storage medium may include a buffer in which data is temporarily stored.
A method according to an embodiment of the disclosure may be provided by being included in a computer program product. The computer program product may be traded between a seller and a buyer as commodities. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed (e.g., downloaded or uploaded) online either via an application store or directly between two user devices (e.g., smartphones). In the case of the online distribution, at least a part of a computer program product (e.g., downloadable app) is stored at least temporarily on a machine-readable storage medium, such as a server of a manufacturer, a server of an application store, or memory of a relay server, or may be temporarily generated.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023133960 | Dec 2023 | RU | national |
This application is a continuation application, under 35 U.S.C. § 111(a), of international application No. PCT/KR2024/020177, filed on Dec. 10, 2024 which claims priority under 35 U. S. C. § 119 to Russian Patent Application No. 2023133960, filed on Dec. 19, 2023, in the Russina Patent Office, the disclosures of which are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/KR2024/020177 | Dec 2024 | WO |
| Child | 18986000 | US |
