Drying moisture absorbent for dehumidifying units

Abstract

In an appliance configured to blow air, a dehumidifying unit 50 is used to ensure that the air expelled from the appliance is dry air. This is particularly advantageous when the air is used for drying purposes such as drying hair. The dehumidifying unit 50 is configured to allow an air flow to pass and to dehumidify the air flow, the dehumidifying unit 50 comprising a desiccant 56 and a heater 51, the heater 51 having a wall structure 52 including at least one compartment 55, the desiccant 56 being disposed in at least one such compartment 55. Advantageously, the heater 51 of the dehumidifying unit 50 is activated for a limited period of time after each time the appliance is operated with an air flow output.

Description

[Technical Field]

[0001] The present invention relates to a dehumidifying unit for use in an appliance having a housing and an air flow generating unit configured to generate an air flow from an air inlet region of the housing to an air outlet region of the housing, the dehumidifying unit configured to allow the air flow to pass through and to dehumidify the air flow, the dehumidifying unit having a desiccant and a heater. [Background technology]

[0002] A practical example of an appliance having a housing and an air flow generating unit configured to generate an air flow from an air inlet area of the housing to an air outlet area of the housing is a hair dryer. Generally, the purpose of a hair dryer is to dry hair from a wet / damp state. The lower the humidity level of the air, the shorter the time required to dry the hair. In this respect, it is advantageous if the blow dryer is equipped with a dehumidifying unit.

[0003] JPH05228012A discloses a hair dryer configured to blow low-humidity air onto hair, resulting in an effective hair drying process. The known hair dryer includes an impeller with a regenerative heater at its center, multiple blades arranged on the periphery of the impeller, a dry air passage, a regenerative air passage, a dry heater provided at the discharge port of the dry air passage, a switching plate for switching between the dry air passage and the regenerative air passage, and a switch. To absorb moisture in the air, a dehumidifying agent such as silica gel is supported on the blades arranged on the periphery of the impeller.

[0004] The switch can set three states of the hair dryer: off, dry, and regenerate. In the dry state of the hair dryer, the switch plate is in a position that directs the airflow induced by the impeller to the dry air passage while closing the regeneration air passage to the airflow. In the regeneration state of the hair dryer, the switch plate is in a position that directs the airflow induced by the impeller to the regeneration air passage while closing the dry air passage to the airflow.

[0005] When a user of a hair dryer wants to dry their hair, they operate a switch to set the hair dryer to a dry state. The impeller rotates, causing air to be drawn in and pass through the silica gel supported on the blades. The silica gel absorbs moisture from the air, resulting in dehumidification. The dehumidified air is pushed by the blades and moves to the outer periphery of the impeller under the influence of centrifugal force caused by the rotation of the impeller. The dehumidified air then flows along the dry air passage and is heated by the dry heater to a relatively low temperature that is safe for hair. Finally, the dehumidified air is discharged from the exhaust port of the dry air passage.

[0006] Silica gel is nearly colorless in its dry state, but as it absorbs moisture from the air, it gradually turns blue and red. A user can check the color of the silica gel on the impeller blades through the notch in the hair dryer that allows air to enter the impeller, thereby determining the moisture absorption state of the silica gel at a glance. When the user confirms that the color of the silica gel is blue or even red, the user switches the hair dryer to the regeneration state using the switch. As described above, in the regeneration state of the hair dryer, the switch plate directs the airflow induced by the impeller into the regeneration air passage while closing the dry air passage to the airflow. Furthermore, the impeller rotates, and the regeneration heater is powered to achieve a high temperature on the impeller's central shaft. As a result, the moisture absorbed by the silica gel evaporates. Due to the influence of the rotating impeller, the air carrying the evaporated moisture is forced away from the impeller and flows through the regeneration air passage, eventually being discharged from the exhaust port of the regeneration air passage. As a result of the regeneration process, in which the impeller is rotated and the regeneration heater is activated, the silica gel returns to a dry state, ready to efficiently absorb moisture from the air in the next drying process. Summary of the Invention [Problem to be solved by the invention]

[0007] A disadvantage of the hair dryer known from JPH05228012A is that the effectiveness of the drying process, as explained, depends on the user's action, i.e., checking the color of the silica gel and, if appropriate, operating the hair dryer in regeneration mode. Another disadvantage is that the regeneration heater needs to generate a large amount of heat in order to heat the silica gel present on the impeller blades to a temperature high enough to evaporate the water contained in the silica gel.

[0008] It is an object of the present invention to provide a dehumidification unit that is compact and robust and is designed so that the desiccant can be effectively regenerated at relatively low temperatures without necessarily relying on user action to initiate the regeneration process. [Means for solving the problem]

[0009] The present invention provides a dehumidification unit for use in an appliance having a housing and an airflow generating unit configured to generate an airflow from an air inlet region of the housing to an air outlet region of the housing, the dehumidification unit being configured to allow the airflow to pass through and to dehumidify the airflow, the dehumidification unit having a desiccant and a heater, the heater having a wall structure including at least one compartment, and the desiccant being disposed in the at least one compartment.

[0010] From the above definition, in the dehumidifying unit according to the present invention, the heater has a dual function, namely, the first function of heating and the second function of containing the desiccant. Advantages of the specific design of the heater wall structure with at least one compartment include allowing the dehumidifying unit to be compact and robust, which is highly desirable in handheld appliances such as hair dryers, and the close placement of the heater and desiccant allows the heat generated by the heater to be transferred to the desiccant in the most efficient manner.

[0011] According to a practical option present in the context of the present invention, the heater wall structure comprises at least two compartments. In this case, the desiccant may be arranged in all of the at least two compartments, but this is not necessary. For example, the heater wall structure may have a grid of strips and strips that contain the grid of strips. Another possibility is for the heater wall structure to have a honeycomb shape, with honeycomb-shaped cells constituting the at least two compartments in the wall structure.

[0012] The heater can be of any suitable type. According to one possible example, the heater comprises a positive temperature coefficient (PTC) material. Regarding the above-mentioned possibility that the wall structure of the heater has a honeycomb shape, the heater may be a honeycomb PTC heater, where it should be noted that compared to conventional designs of such type of heater, the heater design may need to be adjusted to have cells large enough to contain the desiccant.

[0013] It is a commonly known fact that a PTC heater typically comprises at least one piece of PTC material, sandwiched between a pair of electrodes that connect to a metal (silver) coating on the PTC material. When a voltage is applied to the piece of PTC material, the PTC material generates heat. In this process, the temperature is controlled based on a self-regulating mechanism, since PTC material has the property that its internal resistance increases as the temperature increases. This ensures that the temperature remains below the maximum temperature associated with the exact composition of the PTC material.

[0014] According to another possible example, the heater is a ceramic heater. An advantageous aspect of applying a ceramic heater is that it does not need to have electrodes on the opposing surfaces of the heater. Instead, the ceramic heater has a heater track embedded inside. Therefore, the ceramic heater occupies minimal space. To limit the temperature of the ceramic heater, any suitable additional elements can be used, such as an external temperature sensor, a microprocessor that controls the temperature based on input from the sensor, and a mechanical temperature-sensitive switch near the heater to cut off the power supply to the heater if the microprocessor fails or if the electrical circuit containing the sensor, microprocessor, and heater fails.

[0015] In a practical embodiment, the dehumidifying unit comprises two breathable covers, between which at least a portion of the wall structure of the heater is sandwiched, for example the covers comprising a sheet with holes, optionally comprising a plastic material such as a nylon material that can withstand the heat generated by the heater during operation.

[0016] In the context of the present invention, any suitable type of desiccant can be applied. According to one of many practical possibilities, the desiccant is of the type comprising silica gel beads.

[0017] The present invention further relates to an appliance comprising a housing, an air flow generating unit configured to generate an air flow from an air inlet region of the housing to an air outlet region of the housing, and a dehumidifying unit as defined and described above. Advantageously, the dehumidifying unit is located near the air inlet of the housing. It is also advantageous if the dehumidifying unit is configured to cover the entire air inlet region, so that the desiccant is spread throughout the entire air inlet region, so that substantially all of the incoming air can actually be dehumidified.

[0018] The appliance may further include an airflow heater positioned downstream of the dehumidification unit when viewed in a direction from the air inlet region of the housing toward the air outlet region of the housing. The airflow heater functions to heat the outlet air to a desired temperature and may be activated during operation of the appliance as a default or based on input provided by a user. The airflow heater may be configured to generate a greater amount of heat than the heater of the dehumidification unit.

[0019] Efficient utilization of the dehumidification unit is always maintained when the heater of the dehumidification unit is automatically activated after each dehumidification operation on the airflow by the dehumidification unit in order to dry the desiccant so that it is available for the next dehumidification operation. From this perspective, it is advantageous for the above-mentioned appliance to include a controller programmed to keep the heater of the dehumidification unit in an inactive state when the appliance is switched to a state in which it outputs an airflow, and to activate the heater of the dehumidification unit for a limited period of time when the appliance is returned to an inactive state from a state in which it outputs an airflow. If the appliance has the above-mentioned airflow heater, it is particularly advantageous if the controller is programmed to activate the airflow heater while keeping the heater of the dehumidification unit in an inactive state when the appliance is switched to a state in which it outputs warm air, and to deactivate the airflow heater when the appliance is returned to an inactive state, at which point the heater of the dehumidification unit is activated for only a limited period of time.

[0020] A practical example of the appliance defined and described above is a hair dryer. In a more general sense, the appliance may be any household appliance or personal care appliance.

[0021] The above-mentioned and other aspects of the invention will be apparent from and elucidated with reference to the following detailed description of embodiments of a hair dryer with a dehumidifying unit and a dehumidifying unit. [Brief explanation of the drawings]

[0022] [Figure 1]1 shows a schematic diagram of a hair dryer according to an embodiment of the present invention having a dehumidifying unit; [Figure 2] 1 shows diagrammatically elements of a dehumidification unit according to a first embodiment of the invention; FIG. [Figure 3] FIG. 6 is a diagrammatic view of a heater of a dehumidifying unit according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] The invention will now be explained in more detail with reference to the figures, in which like or similar parts are designated with the same reference numerals.

[0024] Figure 1 shows a hair dryer 100 according to an embodiment of the present invention, as an example of an appliance within the scope of the present invention. It should be noted that for clarity, Figure 1 is of a schematic nature only, showing the various elements of the hair dryer 100 in a simplified manner.

[0025] The hair dryer 100 is a handheld appliance intended to be applied by a user to dry the hair with a stream of (hot) air. In this example, the hair dryer 100 comprises: a handle 10 that allows a user to hold the hair dryer 100 in their hand; a housing 20 having an air inlet 21 and an air outlet 22, the housing 20 being practical if it has a generally circular or elliptical outer periphery, and more practical if the air inlet area 22 comprises a plurality of relatively small holes and the air outlet area 22 comprises a single relatively large opening; an air flow generating unit (30) that functions to generate an air flow from the air inlet region (21) of the housing (20) to the air outlet region (22) of the housing (20), the air flow generating unit (30) having a rotatable impeller (31); an airflow heater 40 that functions to heat the airflow within the housing 20, and when the airflow heater 40 is activated, hot air is blown out of the hair dryer 100, and the airflow heater 40 can be, for example, a wire heater supported on a mica frame; a dehumidifying unit (50) that serves to dry the airflow within the housing (20), ensuring that the air blown out of the hair dryer (100) is dry; a microcontroller 60 that serves as the controller for the operation of the hair dryer 100; For example, the hair dryer 100 has a switch 70 that can be operated by a user to set the state of the hair dryer 100, such as a hot air blowing state, a cold air blowing state, or a non-operating state.

[0026] This example shows a practical arrangement of the dehumidifying unit 50 within the housing 20, i.e., an arrangement in which the dehumidifying unit 50 is located near the air inlet region 21 of the housing 20. In particular, in this example, during operation of the hair dryer 100, air drawn into the housing 20 under the influence of the rotating impeller 31 passes through the dehumidifying unit 50, the impeller 31, and the air flow heater 40 in sequence before exiting the housing 20. In this process, the air is dried at the position of the dehumidifying unit 50, and then heated at the position of the air flow heater 40 if the state of the hair dryer 100 set by the user includes the operation of the air flow heater 40. It is advantageous for the hair dryer 100 to blow dehumidified air in order to effectively perform the desired hair drying function. Without the dehumidifying unit 50 and without drying the air, the hair drying process would take time, especially when the hair dryer 100 is operated in a relatively wet environment, such as a bathroom where the user has just taken a shower or bath. The direction of airflow through housing 20 is indicated by arrows in FIG.

[0027] Generally, the dehumidifying unit 50 includes a desiccant and a heater. The airflow passing through the dehumidifying unit 50 is dehumidified due to the interaction between the air and the desiccant. The heater functions to regenerate the desiccant by evaporating absorbed moisture. Advantageously, the microcontroller 60 is programmed to activate the heater of the dehumidifying unit 50 for a limited period of time after each hair drying operation. This ensures that the moisture absorption capacity of the desiccant is optimal at the start of the hair drying operation. It is assumed that the user will leave the hair dryer 100 connected to the mains power supply to regenerate the desiccant. Alternatively, the hair dryer 100 may include a (rechargeable) battery capable of providing sufficient power to allow the regeneration operation to be performed without being connected to the mains power supply.

[0028] Elements of a dehumidifying unit 50 according to a first embodiment of the present invention are shown in FIG. 2. A notable feature of this embodiment is that the wall structure 52 of the heater 51 of the dehumidifying unit 50 includes a grid of strips 53 and strips 54 surrounding the grid of strips 53, which are curved in a circular shape in this example. The grid of strips 53 defines compartments 55, and desiccant 56 is present in at least a selection, and preferably all, of the compartments 55, as shown in FIG. 2. In FIG. 2, the desiccant 56 is depicted as a collection of beads. A practical example of a material for the heater 51 is a positive temperature coefficient (PTC) material, and a practical example of the desiccant 56 is silica gel, which may be provided in beads.

[0029] The dehumidifying unit 50 according to the first embodiment of the present invention further comprises two covers 57, 58 that close opposite sides of the heater 51 filled with desiccant 56. The covers 57, 58 have sheets with holes 59 through which air can pass. It should be understood that the holes 59 are small enough to allow the covers 57, 58 to hold the desiccant 56 in separate compartments 55 in the wall structure 52 of the heater 51. Brackets or the like can be used to hold the covers 57, 58 in place on the heater 51.

[0030] A heater 51 of a dehumidification unit 50 according to a second embodiment of the present invention is shown in Figure 3. Except for the design of the heater 51, the dehumidification unit 50 according to the second embodiment of the present invention may be identical to the dehumidification unit 50 according to the first embodiment of the present invention.

[0031] The wall structure 52 of the heater 51 of the dehumidification unit 50 according to the second embodiment of the present invention has a honeycomb shape, the cells of which form compartments 55 housing the desiccant 56. In fact, the heater 51 is a modified honeycomb PTC heater, i.e., a honeycomb PTC heater with enlarged cells to accommodate the desiccant. The present invention covers the use of alternative types of heaters, such as ceramic heaters, and essentially the heater 51 can be made of any suitable type of material or any suitable combination of materials.

[0032] In any of the above-described embodiments, it is sufficient to operate the heater 51 at a temperature significantly lower than the temperature produced by the airflow heater 40 of the hair dryer 100 during operation in order to remove absorbed moisture from the desiccant 56.

[0033] The scope of the present invention is not limited to the above examples, and it will be apparent to those skilled in the art that several modifications and variations thereof are possible without departing from the scope of the present invention as defined in the appended claims. It is intended that the present invention be construed as including all such modifications and variations insofar as they come within the scope of the claims or their equivalents. Although the present invention has been illustrated and described in detail in the drawings and description, such illustration and description are merely explanatory or exemplary and are not restrictive. The present invention is not limited to the disclosed embodiments. The drawings are schematic, in which details not necessary for understanding the invention may be omitted and are not necessarily drawn to scale.

[0034] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the figures, the description, and the appended claims. In the claims, the word "comprising" does not exclude other steps or elements, and the indefinite article "a" or "an" does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope of the invention.

[0035] Elements and aspects discussed for or in connection with a particular embodiment can be combined with elements and aspects of other embodiments as appropriate, unless otherwise expressly stated. Thus, the mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0036] The terms "having" and "including" as used herein will be understood by those skilled in the art to cover the term "consisting of." Thus, the terms "having" or "including" may mean "consisting of" in one embodiment, but may mean "including / having / comprising at least the specified species and, optionally, one or more other species" in another embodiment.

[0037] For the sake of completeness, the terms "dehumidifying" and "drying" as used herein should be understood to have the same meaning. Furthermore, references herein to a process for regenerating desiccant 56 should be understood as references to a process for dehumidifying desiccant 56.

[0038] Notable aspects of the present invention can be summarized as follows: In an appliance 100 configured to deliver air, a dehumidifying unit 50 is used to ensure that the air delivered from the appliance 100 is dry air. This is particularly advantageous when the air is used for drying purposes, such as drying hair. The dehumidifying unit 50 is configured to allow an air flow to pass through and to dehumidify the air flow, the dehumidifying unit 50 comprising a desiccant 56 and a heater 51, the heater 51 having a wall structure 52 including at least one compartment 55, the desiccant 56 being disposed in the at least one compartment 55. Advantageously, the heater 51 of the dehumidifying unit 50 is activated for a limited period of time after each time the appliance 100 is operated in a state where it outputs an air flow.

Claims

1. A dehumidifying unit for use in an appliance having a housing and an airflow generating unit that generates an airflow from an air inlet region of the housing to an air outlet region of the housing, the dehumidifying unit allowing an airflow to pass through and dehumidifying the airflow, the dehumidifying unit having a desiccant and a heater, the heater having a wall structure including at least one compartment, the desiccant being disposed in the at least one compartment; the dehumidifying unit has two breathable covers, and at least a portion of the heater wall structure is sandwiched between the covers; The dehumidifying unit wherein the cover comprises a sheet with holes.

2. The dehumidifying unit of claim 1 , wherein the heater wall structure includes at least two compartments, and the desiccant is disposed in at least one of the at least two compartments.

3. The dehumidification unit of claim 2 , wherein the desiccant is disposed in all of the at least two compartments.

4. 3. The dehumidifying unit of claim 2, wherein the heater wall structure comprises a grid of strips and strips containing the grid of strips.

5. the heater wall structure has a honeycomb shape; 3. The dehumidifying unit of claim 2, wherein the honeycomb-shaped cells define the at least two compartments in the wall structure.

6. 6. A dehumidifying unit according to any preceding claim, wherein the heater is a positive temperature coefficient heater or a ceramic heater with an embedded heater track therein.

7. 6. A dehumidifying unit according to any preceding claim, wherein the cover comprises a plastic material.

8. 6. A dehumidifying unit according to any preceding claim, wherein the desiccant comprises silica gel beads.

9. 6. An appliance comprising a housing, an air flow generating unit for generating an air flow from an air inlet area of the housing to an air outlet area of the housing, and a dehumidifying unit according to any one of claims 1 to 5.

10. 10. The appliance of claim 9, further comprising an airflow heater located downstream of the dehumidifying unit in a direction from the air inlet area of the housing toward the air outlet area of the housing.

11. 10. The appliance of claim 9, further comprising a controller programmed to keep the heater of the dehumidifying unit in a non-operating state when the appliance is in a state where it outputs an airflow, and to activate the heater of the dehumidifying unit for a limited period of time when the appliance returns from a state where it outputs an airflow to a non-operating state.

12. 10. The device of claim 9, which is either a household device or a personal care device.

13. 13. The device of claim 12, which is a hair dryer.

Images