Clothes dryer, method for drying textiles and control unit

Abstract

The invention relates to a clothes dryer (100) with a drum for receiving textiles, a fan unit (120) for conveying process air from the drum (110) and a filter unit (130) with at least one centrifugal separator (200) for filtering lint from the process air (300) conveyed by the fan unit (120), wherein the filter unit (130) is arranged between the drum and the fan unit (120).

Description

[0001] The invention relates to a clothes dryer, a method for drying textiles and a control unit for carrying out the method.

[0002] WO 2024123479 A1 describes a tumble dryer with an externally mounted cyclone filter.

[0003] The approach presented here aims to create an improved tumble dryer, an improved method for drying textiles, and an improved control unit in accordance with the main claims.

[0004] According to the invention, this problem is solved by a clothes dryer, a method for drying textiles, and a control unit with the features of the main claims. Advantageous embodiments and further developments of the invention are described in the dependent claims.

[0005] The advantages achievable with the invention include, besides increased efficiency of a fan unit, a longer lifespan for the tumble dryer. Improvements in terms of ease of maintenance can also be achieved.

[0006] A tumble dryer is presented which comprises a drum for receiving textiles, a fan unit for conveying process air from the drum and a filter unit with at least one centrifugal separator, wherein the filter unit is designed to filter lint from the process air conveyed by the fan unit, and wherein the filter unit is arranged between the drum and the fan unit.

[0007] The tumble dryer can, for example, be designed as a heat pump dryer. According to one embodiment, the fan unit can, for example, be designed as a radial wheel or include such a radial wheel. The fan unit and the filter unit can, for example, be made of plastic or metal. Alternatively, the fan unit and the filter unit can also be made of a mixture of plastic and metal parts. Furthermore, the centrifugal separator and the filter unit can also improve occupational health and safety and enhance ergonomics, especially since it simplifies the time-consuming removal of lint from the tumble dryer. For example, a person no longer needs to assume a special position to clean the tumble dryer, but can simply remove the lint from a suitable container.

[0008] The centrifugal separator of the filter unit can have at least a partial conical or funnel shape, or a spiral shape, in particular wherein an axis of the centrifugal separator is oriented substantially parallel to an axis of a fan wheel of the fan unit. In this way, lint can be efficiently removed from the airflow.

[0009] The centrifugal separator can be oriented so that the process air is directed tangentially into it. This allows for efficient air intake, enabling the lint to be easily collected at specific points within the filter unit.

[0010] The tumble dryer can have a collection area into which the lint separated in the centrifugal separator is ejected through a discharge opening, in particular where the discharge opening is located at an end opposite an inlet opening of the centrifugal separator. This allows for a central collection of the lint, enabling easy removal of the collected lint from the collection area.

[0011] The collection area can be, for example, an enclosed space or container where lint is collected. This eliminates the need for manual cleaning of the filter fabric. Furthermore, continuous lint removal is possible without a mechanical sieve.

[0012] The collection area can have a backflow opening to allow air from the collection area to pass into the centrifugal separator. The collection area facilitates ergonomic disposal or separation of lint, as it can be removed from the appliance using a collection container. Separating the process air from the maintenance area accessible to the user of the tumble dryer enables integrated protection of the blower.

[0013] Furthermore, the centrifugal separator can have an outlet opening for cleaned air to draw air axially from the separator, particularly if the outlet opening is shaped as a dip tube. This provides a simple solution for removing lint-free air, allowing the lint to be collected at a specific point within the centrifugal separator.

[0014] The tumble dryer can also include at least two centrifugal separators, in particular where the centrifugal separators are of identical design and / or arranged parallel to each other. In this way, lint can be reliably separated from process air even with technically simple and efficient means and high airflow rates.

[0015] The filter unit can further include a filter element, in particular one designed to filter out particles other than lint. This provides increased protection for components downstream and / or upstream of the centrifugal separator, as the risk of mechanical damage to the lint filter or centrifugal separator by hard or large particles such as stones, coins, or detached buttons is significantly reduced. It can also enable a reduction in maintenance intervals for professional service technicians.

[0016] The filter element can be positioned upstream and / or downstream of the centrifugal separator with respect to the airflow, and / or the filter element can be located in an outlet opening of the centrifugal separator. In addition to the aforementioned advantages of reduced risk of damage, this can also lead to a reduction in dust load, as the stirring up or escape of fine lint and dust particles or fluff from the filter can be prevented.

[0017] The filter element can be designed as a filter cartridge, particularly a cylindrical filter cartridge, and / or as a sieve filter and / or fabric filter. By collecting particles, including lint, through the filter element and subsequently directing the lint or particles into the collection area, lint can be collected over several cycles without any reduction in filter performance. Furthermore, the collected lint can be emptied during the drying program. This allows for virtually continuous operational readiness, as the filter does not become clogged during the program runtime. Additionally, the use of a mechanical sieve can be eliminated.

[0018] Furthermore, a method for drying textiles using a tumble dryer is presented, wherein the method includes a step of controlling the fan unit to draw process air from the drum through the filter unit. This method can save time for the user and increase ease of operation.

[0019] The approach presented here further creates a control unit designed to execute, control, and implement the steps of a variant of the method presented here in appropriate devices. This embodiment of the invention, in the form of a device, also allows the underlying problem to be solved quickly and efficiently.

[0020] The control unit can be configured to read input signals and use these input signals to determine and provide output signals. An input signal can, for example, be a sensor signal readable via an input interface of the control unit. An output signal can be a control signal or a data signal that can be provided at an output interface of the control unit. The control unit can be configured to determine the output signals using a processing instruction implemented in hardware or software. For example, the control unit can include a logic circuit, an integrated circuit, or a software module and may be implemented as a discrete component or comprised of a discrete component.

[0021] A computer program product or computer program with program code that can be stored on a machine-readable medium such as semiconductor memory, hard disk memory, or optical memory is also advantageous. If the program product or program is executed on a computer or control unit, it can be used to carry out, implement, and / or control the steps of the method according to one of the embodiments described herein.

[0022] Although the described approach is based on a household appliance, the approach described here can be used accordingly in connection with a commercial or professional device, for example a medical device, such as a cleaning or disinfection device, a small sterilizer, a large-capacity disinfector or a container washing system.

[0023] An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. It shows Figure 1 is a schematic representation of an embodiment of a clothes dryer; Figure 2 is a perspective sectional view of an embodiment of a clothes dryer; Figure 3 is a sectional view of an embodiment of a clothes dryer; Figure 4 is a perspective view of an embodiment of a filter unit of the clothes dryer; Figure 5 is a representation of an embodiment of a filter unit of the clothes dryer; Figure 6 is a sectional view of an embodiment of a clothes dryer; and Figure 7 is a flowchart of an embodiment of a method for drying laundry.

[0024] Figure 1Figure 1 shows a schematic representation of an exemplary embodiment of a clothes dryer 100. The clothes dryer 100 can be designed as a household appliance or as a commercial appliance. Like conventional clothes dryers, the clothes dryer 100 has a drum 110 for holding textiles. A flow of process air is passed through the drum 110, drying the textiles inside. This process air is conveyed within the clothes dryer 100 by a fan unit 120. A filter unit 130 is arranged between the fan unit 120 and the drum 110. The filter unit 130 is designed to filter or remove lint, fluff, or similar particles from the process air. For this purpose, the filter unit 130 includes, for example, a centrifugal separator.Furthermore, the tumble dryer 100 includes a control unit 140, which is intended to dry textiles in the tumble dryer by controlling the fan unit 140 to convey process air from the drum 110 through the filter unit 130.

[0025] The tumble dryer 100 includes an opening 150 through which fresh air is drawn in. This fresh air is then heated by a heating element 160. The heated air is directed into the drum 110, where it dries wet textiles. Subsequently, the process air is drawn or passed through the filter unit 130 by the fan unit 120. The filter unit 130 is located, for example, in a lint chamber 170. After passing through the filter unit 130, the filtered air can either be discharged from the tumble dryer 100 through an outlet 180 or reused for another drying cycle.

[0026] In both private and commercial tumble dryers, textiles with high residual moisture are dried using heated air. Ambient air is drawn in and heated. Due to its physical properties, this heated air can hold more moisture than air at a lower temperature. The heated air is then directed into the drying chamber, which is usually a drum. As the heated air flows around the damp textiles, it absorbs the moisture bound within them. The air is then extracted from the drum and either released into the surrounding environment (especially in a vented dryer) or passed over a condenser, where the increased humidity condenses (especially in a condenser dryer). In commercial dryers, it is quite common for some of the process air to be recirculated and reintroduced into the drying process (recirculating air dryers).To protect the components of the fan unit 120 and prevent contamination, the air from the dryer chamber is passed through a lint filter before flowing through the fan unit 120. Lint and other impurities that have detached from the textiles during the drying process are trapped by this lint filter and thus removed from the process air. As the filter becomes increasingly clogged with lint, the performance of the fan unit 120 decreases because the available free airflow cross-section diminishes. This results in a lower airflow and therefore reduced drying performance. Currently, for these reasons, the lint filters must be cleaned after each program cycle. This is usually done manually by the user, for example, with a broom or brush. This purely manual cleaning of the filter carries the risk of damaging the lint filter with each cleaning.A damaged lint filter can lead to problems and further damage to downstream components (e.g., clogging and blockage of air passages, fan jamming due to foreign objects, etc.). Furthermore, the effort required for manual cleaning, especially in commercial settings, is very high due to the amount of lint generated (multiple cleanings of the lint filter per day and machine in commercial dryers, sometimes at ergonomically unfavorable working heights). Manual cleaning also always carries the risk of fine lint being stirred up again and, in the worst case, inhaled by the user. Therefore, there is always a certain health risk involved.

[0027] Methods can be used in which lint and other foreign matter are mechanically removed from the airflow by lint filters. In these methods, the lint or foreign matter is trapped by the small mesh size of the lint filter. The design of the lint filters varies depending on the dryer size in terms of construction, mesh size, filter area, and filter material (e.g., nylon or metal filters). Furthermore, multi-stage mechanical filters are sometimes used, which essentially consist of a series of filters with different mesh sizes. These are usually cleaned manually.

[0028] Due to the continuous accumulation of lint in the lint filter during the program, the airflow decreases as the program duration increases. If the lint filter is not cleaned before a new drying cycle, the program duration increases considerably for humidity-controlled drying programs. With time-controlled drying programs, the textiles being dried may still have excessive residual moisture at the end of the cycle, so in extreme cases, the drying process should be repeated. Furthermore, there is a risk of damage to the lint filter during any manual cleaning (e.g., by using unsuitable tools or applying excessive force). Such damage (e.g., due to a tear in the filter) could allow foreign particles and lint to enter downstream components, negatively impacting their function and lifespan.Furthermore, cleaning the lint filters is time-consuming and often only possible in ergonomically awkward positions. The collected lint should usually be gathered manually before being removed from the appliance.

[0029] Figure 2 Figure 1 shows a perspective sectional view of part of an exemplary embodiment of a clothes dryer 100. The clothes dryer 100 is as described in Figure 1. Figure 1 The described clothes dryer is designed as follows. The clothes dryer 100 comprises the filter unit 130 with a centrifugal separator 200 in the lint chamber 170, the fan unit 120, and a collection area 210. The collection area 210 is located below the centrifugal separator 200 and is designed to collect the contaminants that the filter unit 130 has filtered from the air. The dust particles or lint fall into the aforementioned collection area 210 by gravity.

[0030] According to this embodiment, the filter unit 130 comprises six centrifugal separators 200 (which may, but are not necessarily, of identical construction) arranged parallel to one another. In one embodiment, the centrifugal separators 200 are shaped like funnels through which the air is guided. Alternatively, the centrifugal separators may also have the shape of a truncated cone or a spiral. A particular feature of this embodiment is that the shape of the centrifugal separators 200 narrows along an axis 220. This ensures that lint is first pressed against the wall by the centrifugal separators and subsequently guided into the collection area 210. The axis 220 of the centrifugal separators 200 is arranged parallel to an axis of the fan unit 120, so that an airflow is conveyed through the centrifugal separators 200. This airflow is directed tangentially into the centrifugal separators 200.The centrifugal separators 200 are oriented such that their axis 220 is parallel to the flow direction of the process air. The centrifugal separators 200 are, for example, located below the drum 110. The inlet to the centrifugal separators 200 is situated between the outlet of the drum 110 and the dryer front.

[0031] According to this embodiment, the collection area 210 is arranged below the centrifugal separators 200. Lint filtered by the centrifugal separators 200 is then directed into the collection area 210 to prevent the air passages in the clothes dryer, specifically the fan unit 120, from becoming clogged with dust or lint, thus preventing a reduction in the fan unit's performance. The collection area 210 is designed as an enclosed space and is connected to the centrifugal separators 200, for example, by a discharge opening 230. The discharge opening 230 of a centrifugal separator 200 is located opposite an inlet opening of the centrifugal separator 200. Each of the six centrifugal separators includes, for example, the discharge opening 230 and the inlet opening. The description and the embodiment shown in the figures comprise six cyclone separators arranged in parallel in the airflow.The description also applies to embodiments not shown, with more or less cyclone separator in the airflow.

[0032] Figure 3 Figure 1 shows a sectional view of part of an exemplary embodiment of a clothes dryer 100. The clothes dryer 100 is like the one in Figure 100. Figure 1 or 2 The described tumble dryer 100 is shaped as follows. Process air 300 is directed from the drum into the lint chamber 170. More precisely, the process air 300 is directed into the centrifugal separator 200, which directs the process air 300 tangentially to the previous flow direction. The filter unit has a filter element 310, which is shaped to filter out lint and other substances or particles different from lint from the process air 300.

[0033] The filter element 310 is arranged in the clothes dryer 100 such that the process air 300 is first passed through the centrifugal separator 200 and then through the filter element 310. Alternatively or additionally, the process air can also be passed, for example, first through the filter element 310 and then through the centrifugal separator 200. The flow direction of the process air 300 is shown here with arrows. In this embodiment, the filter element 310 is arranged between the outlet opening of the centrifugal separator 200 and the inlet opening of the blower 120, and is thus downstream of the centrifugal separator 200 with respect to the airflow. The filter element 310 is, for example, arranged at an angle to the axis 220 of the centrifugal separator 200. Furthermore, the filter element 310 is designed, for example, as a filter cartridge, a screen filter, or a fabric filter.The filter element 310 can be, in particular, a cylindrical filter candle.

[0034] By diverting the lint through the filter element 310, no moving parts that are prone to wear are used. This allows the user to operate a clothes dryer with minimal or no maintenance. The main advantage of this arrangement is an additional filter stage before the process air enters the blower 120. This can be particularly relevant for heat pump dryers, as even the finest lint can clog the heat exchangers. The mesh size of this filter element ensures that particles not removed from the process air by the centrifugal separator 200 are also captured.

[0035] Figure 4 Figure 1 shows a perspective view of an embodiment of a filter unit 130 of the tumble dryer. The filter unit 130 is like the one in Figure 1. Figure 1The described filter unit is formed. The components of filter unit 130 are shown in more detail. Filter unit 130 again includes the centrifugal separator(s) 200. Each centrifugal separator 200 has an inlet opening 400 through which process air is introduced into the centrifugal separator 200. The process air is then guided through a screw conveyor 410, which is connected to a main body 420 of the centrifugal separator 200, for example, a truncated cone. The main body 420 of the centrifugal separator 200 then opens into the discharge opening 230, which directs the lint into the collection area. Adjacent to the discharge opening 230 is a return flow opening 430. Through the return flow opening 430, air from the collection chamber 210 can be drawn back into the cyclone 200. The tangential alignment immediately sets it into rotation, and lint / foreign particles, which may be present, are immediately removed.The lint, which has been "carried along," can be separated again by centrifugal force. This allows for a defined pressure equalization. The basic principle is that the lint falls through the discharge opening 230 into the collection chamber 210. This displaces volume. This volume equalization is ensured via the return flow opening 430.

[0036] According to one embodiment, the return flow opening 430 is shaped to allow air from the collection area to pass back into the centrifugal separator 200. For example, in the Figure 4Three centrifugal separators 200 are more easily visible. The air is then directed out of the outlet opening 440 to draw air axially from the centrifugal separator 200 and prevent lint from being stirred up in the collection area and re-entering the filter unit 130. Since, during operation of the centrifugal separator 200, not only lint but also air is conveyed through the discharge opening 230 into the collection area, a defined return flow opening 430 is provided at the lower end of the cyclone. Pressure equalization takes place via this opening, and the air conveyed into the collection area is drawn into the centrifugal separator 200 and thus reintroduced into the process. The centrifugal separator 200 can therefore be understood, for example, as a tangential cyclone filter with a main axis parallel to the main flow direction.

[0037] Figure 5Figure 1 shows an embodiment of a filter unit 130 for the tumble dryer. The filter unit 130 is like the one shown in Figure 130. Figure 1 The described filter unit is formed. The filter unit 130 again comprises six centrifugal separators 200, which are arranged in the lint chamber 170 and each includes an outlet opening 440. In addition to the lint chamber 170, the collection area 210 is shown here, which is located in the lower area of ​​the lint chamber 170 below the centrifugal separators 200.

[0038] Figure 6 Figure 1 shows a sectional view of part of an exemplary embodiment of a clothes dryer 100. The clothes dryer 100 is like the one in Figure 100. Figure 1The described clothes dryer is designed as follows. The clothes dryer 100 comprises the filter unit 130 with the centrifugal separator 200 in the lint chamber 170. The centrifugal separator 200 is designed here in the same way as the previously described centrifugal separators and their illustrated features. The centrifugal separator 200 comprises the outlet opening 440, the screw 410, the main body 420, and the filter element 310.

[0039] According to one embodiment, the filter element 310 is designed here as a fine filter to filter lint from the air. The filtered air is then returned through the outlet opening 440. The outlet opening 440 is designed as a dip tube.

[0040] The Figure 6This refers to the lint chamber 170 of the dryer. During the drying process, the process air is drawn from the dryer drum by the fan unit. It is then passed through the lint chamber 170, where it is cleaned of the lint present in the process air. Centrifugal separators 200, mounted parallel to each other, are used to filter the lint from the process air. The airflow towards the centrifugal separators is tangential. The blower creates a negative pressure on the side of an inlet nozzle 600, which draws the process air, along with the lint, from the drum above the lint chamber 170. The internal design of the front section of the centrifugal separators 200 as a screw 410 sets the air in rotation.A conically tapered main body 420, hereinafter referred to as the funnel, of the centrifugal separator 200 enables the lint, which has a greater mass than air, to be forced against the side walls by centrifugal force. The lint thus separated rotates within the main body 420 until it reaches its bottom and is then conveyed through a discharge opening into a separate chamber isolated from the rest of the process air. The collected lint can then be removed from this chamber.

[0041] The filtration efficiency of the centrifugal separator 200 can be further enhanced by additional, optionally installed filters. This makes it possible, for example, to filter out any remaining particles before they enter the inlet nozzle 600. Possible options include a cylindrical fine filter or filter cartridge inside the centrifugal separator 200, positioned where the immersion tube would normally be, and / or a flat filter installed outside the centrifugal separator 200, in front of the blower or inlet nozzle 600. Both filters can be designed as either fabric filters or depth filters, for example, to protect heat exchangers in heat pump dryers even more effectively from contamination by fine particles.

[0042] The purified air is then drawn axially out of the centrifugal separator 200 through the immersion tube. The purified air then flows through the inlet nozzle 600 into the blower. Due to the aforementioned design and the compact size of the centrifugal separator 200, the intake air is reliably set into rotation. The larger the particles in the airflow, the more reliably they are separated. Multiple counterflow cyclones, at least two, are used in parallel as centrifugal separators 200. By using a standard component of the centrifugal separator 200, various dryer sizes can be accommodated via a modular design.The air inlet of the centrifugal separator 200 is located in the front area, the funnel extends to the rear in the direction of the main flow towards the fan unit, and the outlet opening 440 for the cleaned air is located at the front of the centrifugal separator.

[0043] Figure 7 Figure 1 shows a flowchart of an embodiment of method 700 for drying textiles with an embodiment of a clothes dryer presented here. Method 700 comprises a step 701 of controlling the fan unit to convey process air from the drum through the filter unit.

Claims

1. Clothes dryer (100) comprising: a drum (110) for receiving textiles; a fan unit (120) for conveying process air (300) from the drum (110); and a filter unit (130) with at least one centrifugal separator (200) for filtering lint from the process air (300) conveyed by the fan unit (120), wherein the filter unit (130) is arranged between the drum (110) and the fan unit (120).

2. Clothes dryer (100) according to claim 1, wherein the centrifugal separator (200) of the filter unit (130) has at least partially a truncated cone or funnel shape or a helical shape, in particular wherein an axis (220) of the centrifugal separator (200) is oriented substantially parallel to an axis of a fan wheel of the fan unit (120).

3. Clothes dryer (100) according to claim 2, wherein the centrifugal separator (200) is oriented such that the process air (300) is introduced tangentially into the centrifugal separator (200).

4. Clothes dryer (100) according to one of the preceding claims, with a collection area (210) into which the lint separated in the centrifugal separator (200) is ejected through a discharge opening (230), in particular wherein the discharge opening (230) is arranged on an end opposite an inlet opening (400) of the centrifugal separator (200).

5. Clothes dryer (100) according to claim 4, wherein the collection area (210) has a backflow opening (430) to allow air from the collection area (210) to pass into the centrifugal separator (200).

6. Clothes dryer (100) according to one of the preceding claims, wherein the centrifugal separator (200) has an outlet opening (440) for purified air in order to draw air axially from the centrifugal separator (200), in particular wherein the outlet opening (440) is designed as a dip tube.

7. Clothes dryer (100) according to one of the preceding claims, wherein the clothes dryer (100) comprises at least two centrifugal separators (200), in particular wherein the centrifugal separators (200) are of the same construction and / or are arranged parallel to each other.

8. Clothes dryer (100) according to one of the preceding claims, wherein the filter unit (130) further comprises a filter element (310), in particular wherein the filter element (310) is designed to filter out particles that are different from lint.

9. Clothes dryer (100) according to claim 8, wherein the filter element (310) is located upstream and / or downstream of the centrifugal separator (200) with respect to the airflow and / or wherein the filter element (310) is arranged in an outlet opening (440) of the centrifugal separator (200).

10. Clothes dryer (100) according to one of claims 8 or 9, wherein the filter element (310) is designed as a filter candle, in particular as a cylindrical filter candle and / or as a sieve filter and / or fabric filter.

11. Method (700) for drying textiles using a clothes dryer (100) according to one of claims 1 to 10, comprising a step (701) of controlling the fan unit (120) to convey process air (300) from the drum (110) through the filter unit (130).

12. Control unit (140) configured to perform and / or control the step (701) of the method (700) according to claim 11 in corresponding units.

13. Computer program product with program code for carrying out the method according to claim 11, when the computer program product is executed on a control unit (140) according to claim 12.

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