Desiccant material for drying dehumidification unit

Abstract

In an appliance configured to blow air, a dehumidification unit (50) is used to ensure that air discharged from the appliance is dry air. This is particularly advantageous when air is used for drying purposes, such as for drying hair. A dehumidification unit (50) is configured to allow an airflow to pass therethrough and to dehumidify the airflow, where the dehumidification unit (50) comprises a desiccant material (56) and a heater (51), where the heater (51) has a wall structure (52) comprising at least one compartment (55), and where the desiccant material (56) is located in the at least one such compartment (55). Advantageously, the heater 51 of the dehumidification unit 50 is activated for a limited period of time each time after the appliance has operated in the state for outputting the air flow.

Description

Technical Field

[0001] The present invention relates to a dehumidification unit for use in an appliance, the appliance comprising a shell and an airflow generating unit, the airflow generating unit being configured to generate an airflow from an air inlet area of ​​the shell to an air outlet area of ​​the shell, wherein the dehumidification unit is configured to allow the airflow to pass through and dehumidify the airflow, and wherein the dehumidification unit comprises a desiccant material and a heater. Background Art

[0002] A practical example of an appliance comprising a housing and an air flow generating unit is a hair dryer, the air flow generating unit being configured to generate an air flow from an air inlet region of the housing to an air outlet region of the housing. Generally speaking, the purpose of a hair dryer is to change hair from a wet state to a dry state. The lower the air humidity, the shorter the time required to put the hair into a dry state. In view of this, it is advantageous if the hair dryer is equipped with a dehumidifying unit.

[0003] JPH05228012A discloses a hair dryer configured to blow low-humidity air toward hair so that a hair drying process can be effective. The known hair dryer includes an impeller provided with a regeneration heater at the center, a plurality of blades provided at the periphery of the impeller, a drying air passage, a regeneration air passage, a drying heater provided at an exhaust port of the drying air passage, a switching plate for switching between the drying air passage and the regeneration air passage, and a switch. A dehumidifier such as silica gel is supported on the blades arranged at the periphery of the impeller to absorb moisture from the air.

[0004] With the aid of this switch, three states of the hair dryer can be set, namely, power off, drying and regeneration. In the drying state of the hair dryer, the switch plate is in a position for directing the air flow called by the impeller to the drying air channel and closing the regeneration air channel to the air flow. In the regeneration state of the hair dryer, the switch plate is in a position for directing the air flow called by the impeller to the regeneration air channel and closing the drying air channel to the air flow.

[0005] When the user of the hair dryer desires to dry her / his hair with the help of the hair dryer, she / he operates the switch to set the drying state of the hair dryer. The impeller rotates, and as a result, air is sucked in and passes through the silica gel on the blades. The silica gel absorbs moisture in the air and dehumidifies the air. The dehumidified air is pushed by the blades and moves to the periphery of the impeller under the influence of the centrifugal force generated by the rotation of the impeller. In addition, the dehumidified air 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 almost colorless in a dry state, but as it absorbs moisture from the air, it gradually turns blue and red. The user can determine the hygroscopic state of the silica gel at a glance by checking the color of the silica gel on the impeller blades through the notch in the hair dryer for introducing air into the impeller. When the user sees that the color of the silica gel is blue or even red, she / he should put the hair dryer in the regeneration state with the help of the switch. As mentioned above, in the regeneration state of the hair dryer, the switching plate is in a position for directing the air flow called by the impeller to the regeneration air channel while closing the dry air channel to the air flow. In addition, the impeller is rotated, and the regeneration heater is powered to achieve a high temperature on the central axis of the impeller. As a result, the moisture absorbed by the silica gel evaporates. Under the influence of the rotating impeller, the air carrying the evaporated moisture is guided away from the impeller, flows through the regeneration air channel, and is finally discharged from the discharge port of the regeneration air channel. During the regeneration process in which the impeller is rotated and the regeneration heater is operated, the silica gel is restored to a dry state and is ready to effectively absorb moisture from the air in the next drying process.

[0007] A disadvantage of the hair dryer known from JPH05228012A is that the effectiveness of the drying process depends on the actions of the user, namely the action of checking the color of the silica gel and operating the hair dryer in the regeneration state when appropriate, as explained. 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 sufficiently high temperature to evaporate the water contained in the silica gel.

[0008] It is an object of the present invention to provide a dehumidification unit of such a design that the dehumidification unit can be compact and robust and the desiccant material can be effectively regenerated at relatively low temperatures without having to rely on user action to initiate the regeneration process. Summary of the invention

[0009] The present invention provides a dehumidification unit for use in an appliance, the appliance comprising a shell and an airflow generating unit, the airflow generating unit being configured to generate an airflow from an air inlet area of ​​the shell to an air outlet area of ​​the shell, wherein the dehumidification unit is configured to allow the airflow to pass through and dehumidify the airflow, wherein the dehumidification unit comprises a desiccant material and a heater, wherein the heater has a wall structure comprising at least one compartment, and wherein the desiccant material is located in at least one such compartment.

[0010] According to the above definition, in the dehumidifying unit according to the invention, the heater has a dual functionality, namely a primary functionality of heating and a secondary functionality of containing the desiccant material. The advantages of the specific design of the wall structure of the heater with at least one compartment include the possibility of the dehumidifying unit being compact and robust, which is very desirable in hand-held appliances such as hair dryers, and the close arrangement of the heater and the desiccant material so that the heat generated by the heater can be transferred to the desiccant material in the most efficient way.

[0011] According to a practical option present in the context of the present invention, the wall structure of the heater comprises at least two compartments. In this case, the desiccant material can be located in all of the at least two compartments, but this is not necessary. For example, it is possible that the wall structure of the heater comprises a grid of strips and strips surrounding the grid of strips. Another possibility is that the wall structure of the heater has a honeycomb shape and the cells of the honeycomb shape constitute the at least two compartments in the wall structure.

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

[0013] As is known to all, in general, a PTC heater comprises at least one piece of PTC material, and the at least one piece of PTC material is sandwiched between a pair of electrodes, which are connected to a metal (silver) coating on the piece of PTC material. When voltage is applied to the PTC material, the PTC material will generate heat. In this process, the temperature is controlled based on a self-regulating mechanism, because the PTC material has the characteristic that its internal resistance increases as the temperature rises. In this way, it is achieved that the temperature remains below the maximum value related to the exact composition of the PTC material.

[0014] According to another possible example, the heater is a ceramic heater. One advantage of using a ceramic heater is that there is no need to have electrodes on opposite sides of the heater. Instead, the ceramic heater has heater tracks embedded inside it. Therefore, the ceramic heater takes up only minimal space. In order to limit the temperature of the ceramic heater, any suitable additional components can be used, such as an external temperature sensor and a microprocessor for controlling 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 in the event of a failure of the microprocessor or the circuit including the sensor, the microprocessor and the heater.

[0015] In a practical embodiment, the dehumidifying unit comprises two air-permeable covers, wherein at least a portion of the wall structure of the heater is sandwiched between the covers. For example, the covers comprise a sheet provided with holes, wherein optionally, the covers comprise a plastic material, such as a nylon material, which is able to withstand the heat generated by the heater during operation.

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

[0017] The invention also relates to an appliance comprising a housing; 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; and a dehumidifying unit as defined and described herein before. It may be advantageous if the dehumidifying unit is arranged near the air inlet area of ​​the housing. Furthermore, it may be advantageous if the dehumidifying unit is arranged to cover the entire air inlet area and if the desiccant material is spread over the entire air inlet area, so that practically all of the incoming air can be dehumidified.

[0018] The appliance may further comprise an airflow heater arranged at a position downstream of the dehumidifying unit when viewed in a direction from the air inlet region of the housing to the air outlet region of the housing. The functionality of the airflow heater is to heat the exhaust air to a desired temperature and may be activated during operation of the appliance by default or dependent on input provided by a user. The airflow heater may be configured to generate more heat than the heater of the dehumidifying unit.

[0019] When the heater of the dehumidifying unit is automatically activated each time after the dehumidifying unit has performed a dehumidifying action on the airflow, effective use of the dehumidifying unit is maintained at all times, with the purpose of drying the desiccant material so that it is ready for the next dehumidifying action. In view of this, it is advantageous if the above-mentioned appliance is equipped with a controller, which is programmed to keep the heater of the dehumidifying unit deactivated when the appliance is placed in a state for outputting an airflow, and to activate the heater of the dehumidifying unit for a limited period of time when the appliance is placed back from the state for outputting an airflow to a non-operating state. In the case where the appliance includes the aforementioned airflow heater, the controller can be specifically programmed so that when the appliance is placed in a state for outputting a hot airflow, the controller is programmed to activate the airflow heater while keeping the heater of the dehumidifying unit deactivated, and when the appliance is placed back to a non-operating state, the airflow heater is deactivated and at this point the heater of the dehumidifying unit is activated for a limited period of time.

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

[0021] The above and other aspects of the present invention will become apparent with reference to the following detailed description of embodiments of a hair dryer including a dehumidifying unit and a dehumidifying unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will now be explained in more detail with reference to the accompanying drawings, in which the same or similar components are indicated by the same reference numerals, and in which:

[0023] Figure 1 A hair dryer according to an embodiment of the present invention is schematically shown, the hair dryer comprising a dehumidifying unit;

[0024] Figure 2 schematically illustrates components of a dehumidification unit according to a first embodiment of the present invention; and

[0025] Figure 3 A heater of a dehumidifying unit according to a second embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0026] Figure 1 A hair dryer 100 according to an embodiment of the present invention is shown as an example of an appliance within the scope of the present invention. For the sake of clarity, it should be noted that Figure 1 The various components of the hair dryer 100 are shown schematically only and in a simplified manner.

[0027] The hair dryer 100 is a handheld appliance that is intended to be used by a user for the purpose of drying her / his hair by means of a (hot) air flow. In this example, the hair dryer 100 comprises the following components:

[0028] A handle 10, which is used to enable a user to hold the hair dryer 100 in his hand;

[0029] a housing 20 having an air inlet region 21 and an air outlet region 22, wherein it is practical if the housing 20 has a substantially circular or oval outer periphery, and wherein it is more practical if the air inlet region 22 is provided with a plurality of relatively small holes and the air outlet region 22 is provided with a single relatively large opening;

[0030] an airflow generating unit 30 , the functionality of which is to generate an airflow from the air inlet region 21 of the housing 20 to the air outlet region 22 of the housing 20 , comprising a rotatable impeller 31 ;

[0031] An airflow heater 40, the functionality of which is to heat the airflow in the housing 20 so that hot air is blown out of the hair dryer 100 during the time when the airflow heater 40 is activated, and the airflow heater may be, for example, a wire heater supported by a mica frame;

[0032] A dehumidification unit 50, the functionality of which is to dry the airflow in the housing 20, thereby ensuring that the air blown out from the hair dryer 100 is dry air;

[0033] A microcontroller 60, the functionality of which is to control the operation of the hair dryer 100;

[0034] A switch 70 which can be operated by a user to set a state of the hair dryer 100 such as a state for blowing hot air, a state for blowing cold air, and a non-operation state.

[0035] In this example, a practical arrangement of a dehumidifying unit 50 in the housing 20 is shown, i.e. an arrangement in which the dehumidifying unit 50 is located near the air inlet area 21 of the housing 20. Specifically, in this example, during operation of the hair dryer 100, the 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 leaving the housing 20. In the process, the air is dried at the location of the dehumidifying unit 50 and, if the state of the hair dryer 100 set by the user includes activating the air flow heater 40, the air is subsequently heated at the location of the air flow heater 40. The fact that the hair dryer 100 blows dehumidified air is advantageous in effectively performing the desired hair drying functionality. If the dehumidifying unit 50 were not present and the air would not be dried, the hair drying process would take longer, and this is particularly the case when the hair dryer 100 is operated in a relatively humid environment, such as in a bathroom where the user has just showered or bathed. The direction of the air flow through the housing 20 is controlled by means of Figure 1 Indicated by the arrow in the .

[0036] In general, the dehumidifying unit 50 comprises a desiccant material and a heater. The airflow passing through the dehumidifying unit 50 is dehumidified under the influence of the interaction of the air with the desiccant material. The heater regenerates the desiccant material by evaporating the absorbed moisture. Advantageously, the microcontroller 60 is programmed to activate the heater of the dehumidifying unit 50 within a limited time period after each hair drying action has been performed and ended. In this way, it is ensured that the moisture absorption capacity of the desiccant material is optimal at the beginning of each hair drying action. For the purpose of regenerating the desiccant material, the user should leave the hair dryer 100 plugged in to the power supply. On the other hand, it is also possible that the hair dryer 100 is equipped with a (rechargeable) battery capable of delivering power to such an extent that the regeneration action can be performed without being connected to the power supply.

[0037] Figure 2 Components of a dehumidifying unit 50 according to a first embodiment of the present invention are shown. A notable feature of this embodiment is that the wall structure 52 of the heater 51 of the dehumidifying unit 50 comprises a strip grid 53 and strips 54 surrounding the strip grid 53, which in this example are curved into a circle. In the strip grid 53, compartments 55 are defined, and desiccant material 56 is present in at least one selection of these compartments, preferably in all of these compartments 55, such as Figure 2 As shown. Figure 2 , the desiccant material 56 is depicted as a collection of beads. A practical example of the material of the heater 51 is a positive temperature coefficient (PTC) material, and a practical example of the desiccant material 56 is silica gel, which may be provided in the form of beads.

[0038] The dehumidification unit 50 according to the first embodiment of the present invention also includes two covers 57, 58 for closing the opposite sides of the heater 51 filled with the desiccant material 56. The covers 57, 58 include a sheet material provided with holes 59 so that air can pass through. It should be understood that the holes 59 are small enough to enable the covers 57, 58 to hold the desiccant material 56 in the corresponding 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.

[0039] Figure 3 The heater 51 of the dehumidification unit 50 according to the second embodiment of the present invention is shown. Except for the design of the heater 51, the dehumidification unit 50 according to the second embodiment of the present invention may be comparable to the dehumidification unit 50 according to the first embodiment of the present invention.

[0040] The wall structure 52 of the heater 51 of the dehumidifying unit 50 according to the second embodiment of the present invention has a honeycomb shape, wherein the cells of the honeycomb shape constitute compartments 55 for accommodating desiccant material 56. In fact, the heater 51 is an improved honeycomb PTC heater, that is, a honeycomb PTC heater with enlarged cells so that the desiccant material can be loaded. The present invention includes the use of alternative types of heaters, such as ceramic heaters, and in essence, the heater 51 can be made of any suitable type of material or any suitable combination of materials.

[0041] In both previously described embodiments, in order to remove absorbed moisture from the desiccant material 56, it was sufficient to operate the heater 51 at a temperature significantly lower than that generated by the airflow heater 40 of the hair dryer 100 during operation.

[0042] It will be apparent to those skilled in the art that the scope of the present invention is not limited to the examples discussed above, and that various modifications and variations may be made thereto without departing from the scope of the present invention as defined in the appended claims. The present invention is intended to be interpreted as including all such modifications and variations as long as they fall within the scope of the claims or their equivalents. Although the present invention has been described and illustrated in detail in the drawings and the specification, such illustrations and descriptions are to be considered illustrative or exemplary only and not restrictive. The present invention is not limited to the disclosed embodiments. The accompanying drawings are schematic, in which details not necessary for understanding the present invention may be omitted, and are not necessarily drawn to scale.

[0043] Variations to the disclosed embodiments may be understood and effected by those skilled in the art in practicing the claimed invention based on a study of the drawings, the specification, 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.

[0044] Unless explicitly stated otherwise, elements and aspects discussed for or with respect to a particular embodiment may suitably be combined with elements and aspects of other embodiments. 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.

[0045] The terms "comprising" and "including" as used herein will be understood by those skilled in the art to encompass the term "consisting of...." Thus, the term "comprising" or "including" may mean "consisting of" in one embodiment, but may mean "comprising / having / provided with at least the defined substances and optionally one or more other substances" in another embodiment.

[0046] For the sake of completeness, it should be noted that the terms "dehumidification" and "drying" used herein should be understood to have similar meanings. In addition, in this document, references to the process of regenerating the desiccant material 56 should be understood as references to the process of dehumidifying the desiccant material 56.

[0047] The salient aspects of the invention are summarized as follows. In an appliance 100 configured to blow air, a dehumidifying unit 50 is used to ensure that the air exhausted from the appliance 100 is dry air. This is particularly advantageous when the air is used for drying purposes, such as for drying hair. The dehumidifying unit 50 is configured to allow an airflow to pass through and dehumidify the airflow, wherein the dehumidifying unit 50 comprises a desiccant material 56 and a heater 51, wherein the heater 51 has a wall structure 52 comprising at least one compartment 55, and wherein the desiccant material 56 is located in at least one such compartment 55. Advantageously, the heater 51 of the dehumidifying unit 50 is activated each time within a limited time after the appliance 100 has been operated in a state for outputting an airflow.

Claims

1. A dehumidification unit (50) for use in an appliance (100), the appliance comprising a housing (20) and an airflow generating unit (30), the airflow generating unit being configured to generate an airflow from an air inlet region (21) of the housing (20) to an air outlet region (22) of the housing (20), wherein the dehumidification unit (50) is configured to allow airflow to pass therethrough and to dehumidify the airflow, wherein the dehumidification unit (50) comprises a desiccant material (56) and a heater (51), wherein the heater (51) has a wall structure (52) comprising at least one compartment (55), and wherein the desiccant material (56) is located in at least one such compartment (55).

2. The dehumidification unit (50) according to claim 1, wherein the wall structure (52) of the heater (51) comprises at least two compartments (55), and wherein the desiccant material (56) is located in at least one compartment of the at least two compartments (55).

3. The dehumidification unit (50) of claim 2, wherein the desiccant material (56) is located in all of the at least two compartments (55).

4. The dehumidifying unit (50) according to claim 2 or 3, wherein the wall structure (52) of the heater (51) comprises a strip grid (53) and strips (54) surrounding the strip grid (53).

5. The dehumidification unit (50) according to claim 2 or 3, wherein the wall structure (52) of the heater (51) has a honeycomb shape, and wherein cells of the honeycomb shape constitute the at least two compartments (55) in the wall structure (52).

6. The dehumidification unit (50) according to any one of claims 1 to 5, wherein the heater (51) is a positive temperature coefficient (PTC) heater or a ceramic heater with an embedded heater track inside.

7. A dehumidifying unit (50) according to any one of claims 1 to 6, comprising two air-permeable covers (57, 58), wherein at least a portion of the wall structure (52) of the heater (51) is sandwiched between the covers (57, 58).

8. The dehumidifying unit (50) according to claim 7, wherein the cover (57, 58) comprises a sheet material provided with holes (59).

9. The dehumidification unit (50) according to claim 7 or 8, wherein the cover (57, 58) comprises a plastic material.

10. The dehumidification unit (50) according to any one of claims 1 to 9, wherein the desiccant material (56) comprises silica gel beads.

11. An appliance (100), comprising a shell (20); an airflow generating unit (30), the airflow generating unit being configured to generate an airflow from an air inlet area (21) of the shell (20) to an air outlet area (22) of the shell (20); and a dehumidification unit (50) according to any one of claims 1 to 10.

12. The appliance (100) according to claim 11 comprises an air flow heater (40), which is arranged at a position downstream of the dehumidification unit (50) when viewed in the direction from the air inlet area (21) of the shell (20) to the air outlet area (22) of the shell (20).

13. The appliance (100) according to claim 11 or 12, comprising a controller (60), which is programmed to keep the heater (51) of the dehumidification unit (50) deactivated when the appliance (100) is placed in a state for outputting an airflow, and is programmed to activate the heater (51) of the dehumidification unit (50) for a limited period of time when the appliance (100) is placed back from the state for outputting an airflow to a non-operating state.

14. The appliance (100) according to any one of claims 11 to 13, which is a household appliance or a personal care appliance.

15. The appliance (100) according to claim 14, which is a hair dryer.

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