tumble dryer

Abstract

Disclosed herein is a drum dryer (100) having a front side (101) and a rear side (102), the drum dryer (100) comprising: a rotatable inner drum (200) having a circular cross section and extending along an axis A, the inner drum (200) having a first end (201) and a second end (202), wherein the first end (201) is arranged on the front side (101) of the drum dryer (100); a stationary outer drum (300) arranged coaxially with the inner drum (200) and enclosing said inner drum (200), the outer drum (300) having a first end (301) and a second end (302), wherein the first end (301) is arranged on the front side (101) of the drum dryer (100). The drum dryer further comprises a first sealing device (310) and a second sealing device (210).

Description

Technical Field

[0001] This invention relates to the technical field of rotary drum dryers. Background Technology

[0002] Whether in professional environments such as hotels, hospitals, or laundries, or in private settings like homes, the rotary dryer is a cornerstone of the laundry industry. A typical rotary dryer operates by continuously drawing in ambient air, heating it, and then guiding it through a drum containing wet clothes. The heated air removes moisture from the clothes and leaves the drum as hot, humid air. Sometimes this hot, humid air is vented to the surrounding environment outside the dryer to make way for fresh air to enter the drying process.

[0003] Therefore, rotary dryers must handle large volumes of humid air in one way or another, and it is therefore very important to ensure that the humid air is handled properly to avoid damaging some of the dryer's internal parts. Humid air is known to increase the risk of corrosion, can cause short circuits in electrical components, and poses further safety risks to users if the hot, humid air leaving the dryer is near them.

[0004] Reduced drying performance is another problem that can arise from unwanted leakage of process air from the cylinder. Hot air may leak from the cylinder before it is fully saturated with water vapor, thus reducing drying efficiency. Consequently, the drying process requires a larger airflow and, in some cases, prolongs the duration of the drying process.

[0005] Some of these problems can be mitigated by sealing the drum to force hot, humid air out along a desired path. Some examples of seals are gaskets of various designs and materials arranged between the drum and other internal components of the rotary dryer. However, the introduction of gaskets can also mean introducing unwanted friction between internal components, which must be taken into account during the operation of the rotary dryer. Summary of the Invention

[0006] In view of the above, it is desirable to provide alternative solutions to overcome the problems of handling hot and humid air and avoiding the effects of undesirable friction. These and other objectives are achieved by providing an improved rotary dryer, and in particular an improved drum arrangement having the features of the independent claim. Preferred embodiments are defined in the dependent claims.

[0007] Therefore, according to a first aspect of the invention, a rotary drum dryer is provided, having a front side and a rear side. The rotary drum dryer includes a rotatable inner drum having a circular cross-section and extending along an axis A. The inner drum has a first end and a second end, wherein the first end is disposed on the front side of the rotary drum dryer. The rotary drum dryer further includes a fixed outer drum arranged coaxially with and surrounding the inner drum, having a first end and a second end, wherein the first end is disposed on the front side of the rotary drum dryer. Furthermore, the rotary drum dryer includes: a door disposed on the first end of the outer drum and configured to allow access to the inner drum; and a first sealing device configured to seal the space between the first end of the outer drum and the door, wherein the first sealing device is disposed on the surface of the door facing the first end of the outer drum, or on the first end of the drum facing the door. A second sealing device is further provided, configured to seal the space between the inner and outer cylinders. The second sealing device is disposed on at least one surface of the inner cylinder facing the outer cylinder, or alternatively on at least one surface of the outer cylinder facing the inner cylinder. The rotary drum dryer further includes a fan assembly arranged to generate a process airflow through the inner cylinder, wherein the process airflow enters the inner cylinder through at least one opening at a second end of the inner cylinder and exits the inner cylinder radially through at least one opening on the outer periphery of the inner cylinder.

[0008] There are many advantages associated with the rotary dryer according to the invention. For example, the air path of the process airflow can be advantageously controlled by providing openings in the inner cylinder, such that the process airflow is guided through the inner cylinder in a desired direction and exits the cylinder in a controlled manner. By doing so, the drying efficiency of the rotary dryer is improved due to less air leakage.

[0009] The outer cylinder can surround the inner cylinder, creating a gap between them. The distance between the outer cylinder and the inner cylinder forming the gap, along the length of the inner and outer cylinders, can be the same as along the first and second ends of the inner and outer cylinders.

[0010] According to an exemplary embodiment of this disclosure, the outer cylinder has a circular cross-section. The inner and outer cylinders may have a cylindrical shape, wherein the cylindrical body has a first end and a second end. The first end may correspond to the front side of the rotary dryer, and the second end may correspond to the rear side of the rotary dryer. The inner and outer cylinders may be made of metal (e.g., aluminum or stainless steel). The inner and outer cylinders may further be formed of another material suitable for providing insulation. For example, the outer cylinder may be formed of an insulating material to retain heat within the rotary dryer, more specifically within the inner cylinder. Similarly, the inner cylinder may be formed of an insulating material to retain heat from the process air inside the inner cylinder, thereby enhancing the drying effect of the process air inside the inner cylinder. Furthermore, the outer and inner cylinders may be formed of a metallic material, including a sleeve made of insulating material, to combine the effects of a durable material with insulating properties. Therefore, the outer cylinder's circular cross-section can have a larger diameter than the inner cylinder's circular cross-section, allowing the outer cylinder to completely enclose the inner cylinder. This double-cylinder configuration allows for a better seal between the inner cylinder and the rotary dryer. Furthermore, the double-cylinder configuration, with the outer cylinder surrounding the inner cylinder, helps prevent air and / or moisture leakage from the inner cylinder to other components of the rotary dryer. Another advantage is that the double-cylinder configuration enables enhanced insulation, allowing higher temperatures to be reached inside the inner cylinder when drying clothes placed within it.

[0011] Furthermore, the door of the rotary dryer can be located at the first end of the outer drum. The door can be fitted with hinges capable of opening and closing. The first end of the outer drum can have an opening that is covered by the door when closed. Therefore, when the door is open, the opening on the outer drum can be exposed. The first end of the inner drum can have an opening that coincides with the opening on the outer drum, thereby allowing access to the inner drum. Therefore, when the door is open, access to the inner drum can be allowed through both the opening on the outer drum and the opening on the inner drum. Thus, the door can serve as a passageway allowing a user to place and remove clothing from the inner drum. For example, a user can open the door, load clothing into the inner drum, close the door, start the drying program, and when the drying program is complete, open the door to unload the dried clothing and then close the door. The door can have a substantially circular shape and thus match the cross-sectional shapes of the inner and outer drums. The diameter of the door can be smaller than the diameter of the outer drum.

[0012] Furthermore, a first sealing device is arranged to seal the space between the door and the front side of the rotary dryer. This is advantageous because it ensures that no air leaks through the door during the drying process. The first sealing device can be arranged on the front surface of the rotary dryer facing the door. Alternatively, the first sealing device can be arranged on the door surface facing the front side of the rotary dryer. According to an exemplary embodiment of this disclosure, the first sealing device is a gasket. The first sealing device can be made of a malleable material (such as rubber). For example, if the door is circular, the first sealing device can be a gasket arranged on the door around its outer periphery, such that when the door is closed, the gasket abuts the front side of the rotary dryer. Thus, when the door is closed, the first sealing device can be pressed between the door and the front side of the rotary dryer, causing the malleable material to be compressed, thereby sealing the space. The same result can be achieved by arranging the gasket on the front side of the rotary dryer, on the front surface of the rotary dryer facing the door. The shape of the gasket can match the circular cross-section of the door. Furthermore, the first sealing device can be arranged around an opening on the front side of the rotary dryer, which can also be circular in shape. The front side of the rotary dryer can have an opening, and the outer cylinder can be fitted into this opening. Therefore, the size of the opening on the front side of the rotary dryer can be the same as the diameter of the outer cylinder, allowing the outer cylinder to be fitted inside the front side of the rotary dryer.

[0013] Furthermore, the rotary drum dryer includes a second sealing device arranged to seal the space between the inner drum and the outer drum, and arranged on at least one surface of the inner drum facing the outer drum, or alternatively on at least one surface of the outer drum facing the inner drum.

[0014] According to an exemplary embodiment, the second sealing device may be arranged on the first and second ends of the inner cylinder, on the surface facing the outer cylinder. Alternatively, the second sealing device may be arranged on the first and second ends of the outer cylinder, on the surface facing the inner cylinder. Therefore, the second sealing device may be arranged on the first and second ends of the inner cylinder. Thus, the second sealing device may consist of two parts, one part arranged on the first end and the other part arranged on the second end. Therefore, the at least one surface may be two surfaces. Since the inner cylinder has a circular cross-section, the second sealing device may be distributed on the circular surfaces of the first and second ends of the inner cylinder facing the outer cylinder. The second sealing device may be distributed to cover the entire surface of the first and second ends of the inner cylinder. The second sealing device may further conform to the shape of the surfaces of the first and second ends in the form of an annular member. The annular member may be arranged towards the edges of the first and second edges of the inner cylinder. Similarly, the second sealing device may be arranged on the first and second ends of the outer cylinder, on the surface facing the inner cylinder. Therefore, the second sealing device may be arranged on the first and second ends of the outer cylinder, respectively. Because the inner cylinder has a circular cross-section, the second sealing device can be distributed on the circular surfaces of the first and second ends of the outer cylinder facing the inner cylinder. The second sealing device can be distributed to cover the entire surface of the first and second ends of the outer cylinder. The second sealing device can further conform to the shape of the surfaces of the first and second ends in the form of an annular element. The annular element can be arranged towards the edges of the first and second edges of the outer cylinder. For example, in the example where the second sealing device is arranged on the first and second ends of the inner cylinder, the seal can fill the gap between the inner and outer cylinders; conversely, in the example where the second sealing device is arranged on the first and second ends of the outer cylinder, on the surface facing the inner cylinder, the seal can also fill the gap between the inner and outer cylinders.

[0015] According to an exemplary embodiment of this disclosure, the second sealing device is a gasket continuously arranged on a surface facing the outer cylinder body around the outer periphery of the inner cylinder body. Therefore, in an example where the inner cylinder body has a cylindrical body (having a first end and a second end), the second sealing device can be arranged around the outer periphery (i.e., the outer surface of the cylindrical body of the inner cylinder body). Thus, in this example, the at least one surface can correspond to a single surface, i.e., the outer surface of the inner cylinder body. The second sealing device can be distributed around the outer periphery in multiple smaller portions, or it can be a continuous seal around the outer periphery. Furthermore, the second sealing device can be divided into two parts, one part arranged around the outer periphery of the inner cylinder body towards the first end of the inner cylinder body, and another part arranged around the outer periphery of the inner cylinder body towards the second end of the inner cylinder body.

[0016] Similarly, according to an exemplary embodiment of this disclosure, the second sealing device may be arranged around the outer periphery of the outer cylinder on a surface facing the inner cylinder. Therefore, in this example, the at least one surface may correspond to a single surface, namely, the inner surface of the outer cylinder facing the inner cylinder. In the case where the outer cylinder has a cylindrical shape, this surface corresponds to the inner surface of the cylindrical body of the outer cylinder. The second sealing device may be distributed in multiple smaller portions around the periphery, or it may be a continuous seal around the periphery. Furthermore, the second sealing device may be divided into two parts, one part arranged around the outer periphery of the outer cylinder towards a first end of the outer cylinder, and another part arranged around the outer periphery of the outer cylinder towards a second end of the outer cylinder.

[0017] Furthermore, according to an exemplary embodiment of this disclosure, the second sealing device may be arranged on the first and second ends of the inner or outer cylinder, and surrounding the outer periphery of the cylindrical body of the inner or outer cylinder. Therefore, the at least one surface may be three surfaces. Thus, the second sealing device may be divided into a first portion arranged on the surface of the first end of the inner cylinder facing the outer cylinder. A second portion of the second sealing device may be arranged on the surface of the second end of the inner cylinder facing the outer cylinder. A third portion of the second sealing device may be arranged around the outer periphery of the inner cylinder on the outer surface of the cylindrical body of the inner cylinder facing the outer cylinder.

[0018] Similarly, a second sealing device can be alternatively arranged on the outer cylinder. The second sealing device can then be divided into a first portion disposed on the surface of the outer cylinder facing the inner cylinder at a first end. A second portion of the second sealing device can be disposed on the surface of the outer cylinder facing the inner cylinder at a second end. A third portion of the second sealing device can be disposed around the outer periphery of the outer cylinder on the inner surface of the cylindrical body of the outer cylinder facing the inner cylinder.

[0019] The second sealing device can be made of a ductile material (such as rubber). Further, the second sealing device can be made of felt, a brush, or a plastic material. For example, felt or a brush can reduce friction between the outer and inner cylinders while sealing the space between them. Reducing friction between the inner and outer cylinders can be beneficial because it reduces wear on the second seal. Furthermore, reducing friction between the outer cylinder and the rotating inner cylinder is beneficial because it prevents the second seal from impairing the rotational performance of the inner cylinder.

[0020] Therefore, the second sealing device can be advantageously arranged to seal the inner and outer cylinders, allowing the process airflow traveling through them to be advantageously controlled to flow in its intended location, while preventing it from leaking out through openings it is not intended to pass through. The proposed configuration further enables an enhanced vacuum pressure effect inside the inner cylinder, thereby lowering the boiling point of water and accelerating its evaporation, thus removing moisture from clothing placed in the inner cylinder more quickly. Furthermore, the second sealing device can also facilitate the guidance of the process airflow, as it creates an environment with minimized air leakage, preventing air from flowing in unintended directions.

[0021] According to an exemplary embodiment of this disclosure, the second sealing device is a labyrinth seal comprising two mating washers, wherein the first washer is disposed on the inner cylinder and the second washer is disposed on the outer cylinder. Thus, the first washer can be disposed on the first and second ends of the inner cylinder, on the surface of the inner cylinder facing the outer cylinder. Similarly, the second washer can be disposed on the first and second ends of the outer cylinder, on the surface of the outer cylinder facing the inner cylinder. The first and second washers can have shapes that allow them to interlock, such as multiple grooves. Therefore, the labyrinth seal can provide a tortuous path to prevent leakage between the inner and outer cylinders. For example, the first and second washers can have multiple toothed protrusions with grooves between them. The grooves and protrusions can be arranged such that the protrusions on the first washer fit into the grooves on the second washer. Further, in the interlocked state, there can be a gap between the first and second washers. Therefore, low friction or no friction can exist between the first and second washers. The labyrinth seal thus advantageously reduces the energy consumption required to rotate the inner cylinder. Furthermore, lower energy consumption allows for the use of a smaller motor to drive the rotation of the inner cylinder, thereby improving the sustainability of the rotary dryer.

[0022] Furthermore, the rotary dryer includes a fan assembly arranged to generate a process airflow through the inner drum. The fan assembly can guide the process airflow in a desired direction. For example, the fan assembly can be positioned below the outer drum. The fan assembly can include a fan and a motor that drives the fan. The motor can be a geared motor, which allows the fan to be driven at different speeds, thereby controlling the process airflow. The process airflow can be a closed-loop flow, starting from the fan assembly that generates the process airflow and then flowing into the inner drum through at least one opening at a second end of the inner drum. Thereafter, the process airflow can absorb moisture from the clothes placed in the inner drum and then flow out of the inner drum radially through at least one opening on the outer periphery of the inner drum. The rotary dryer can further include a heat pump system for dehumidifying and heating the process airflow. The process airflow can thus flow through the heat pump system after leaving the inner drum (guided by the fan assembly), and then the warm, dry air can re-enter the inner drum. Therefore, the process airflow can be recirculated through the inner drum until the clothes are dried. Therefore, the first and second sealing devices facilitate the retention of the process airflow generated by the fan assembly within the rotary dryer and prevent leakage. This is advantageous because it eliminates the need to draw in ambient air from outside the rotary dryer, thus avoiding the risk of reduced drying capacity due to cold ambient air entering the inner cylinder. Furthermore, the fan assembly is advantageous because it guides the process airflow in the desired direction, thereby enhancing the controllability of the rotary dryer and the drying process. Thus, the fan assembly makes it possible to manage large airflows, which enhances the evaporation capacity and vacuum pressure effect of the process airflow.

[0023] According to an exemplary embodiment of this disclosure, at least one opening on the second end of the inner drum is a plurality of openings. These plurality of openings can be distributed on the surface of the second end of the inner drum facing the outer drum. This is advantageous because it provides a pathway for air to enter the inner drum and dry the clothes placed inside. The plurality of openings allows the process airflow to be distributed on the surface of the second end of the inner drum as it enters. In this way, the process airflow entering the drum is distributed within a certain volume area of ​​the inner drum and can therefore be more evenly distributed on the clothes placed inside the inner drum. This can improve drying performance by shortening the drying time and thus improve the efficiency of the rotary dryer. Furthermore, the plurality of openings distributed on the surface of the second end of the inner drum can also reduce the pressure drop of the process airflow entering from outside the outer drum and flowing through the plurality of openings. This is advantageous because the reduction in pressure drop enables energy savings in the rotary dryer, such as energy savings in the fan assembly and heat pump assembly.

[0024] According to an exemplary embodiment of this disclosure, the outer drum further includes at least one opening disposed at its second end, the at least one opening being arranged to align with at least one opening at the second end of the inner drum. Thus, an opening may also be disposed at the second end of the outer drum on the surface facing the second end of the inner drum. The at least one opening at the second end of the outer drum may further coincide with the inlet of an air duct that leads from the fan assembly to the second end of the outer drum. The outer drum may be connected to an air duct that guides downwards on the rear side of the rotary dryer, behind the inner and outer drums and coupled to a heat pump unit or the like for heating and dehumidifying the process airflow for drying clothes in the inner drum. This is advantageous because the outer drum surrounds the inner drum, and therefore the opening at the second end of the outer drum, together with the at least one opening at the second end of the inner drum, forms a closed path for the process airflow to flow in.

[0025] According to an exemplary embodiment of this disclosure, at least one opening around the outer periphery of the inner drum is a plurality of openings distributed along axis A along length L on the inner drum. In other words, at least one opening on the outer periphery of the inner drum can be a plurality of holes distributed on the outer peripheral surface of the inner drum. In one example, length L may correspond to 50% of the length of the inner drum. In another example, length L may correspond to 25% of the length of the inner drum. It should be understood that the plurality of holes extending along length L may correspond to a shorter portion or a longer portion of the length of the inner drum. Having a plurality of openings distributed along length L is advantageous because it provides a pathway for the process airflow to exit the inner drum once the air has absorbed moisture from the clothing. The plurality of holes allows the process airflow to be distributed over the enlarged surface of the clothing placed in the inner drum and on the outer peripheral surface of the inner drum as the process airflow exits the inner drum. This allows fresh hot air to enter the inner drum, thereby improving the efficiency of the rotary dryer.

[0026] According to an exemplary embodiment of this disclosure, the bottom side of the outer cylinder includes at least one opening perpendicular to the first end. Therefore, when the outer cylinder is cylindrical, at least one opening at the second end of the outer cylinder can be arranged on the outer periphery of the cylindrical body of the outer cylinder. Thus, at least one opening at the second end of the outer cylinder can be arranged on the surface of the second end, i.e., on a side perpendicular to the bottom side of the outer cylinder. This is advantageous because the process airflow can be introduced into the inner cylinder in a direction parallel to axis A and drawn out radially from the cylinder on the bottom side of the outer cylinder. Therefore, the process airflow can flow through the inner cylinder in a semi-axial direction. The semi-axial direction is advantageous because it allows process air turbulence to be generated within the inner cylinder. The process air turbulence can be distributed over the increased volume area of ​​the inner cylinder, thereby reaching more clothes placed in the inner cylinder and enhancing the drying effect of the rotary dryer.

[0027] According to an exemplary embodiment of this disclosure, the position of at least one opening on the bottom side of the outer cylinder corresponds to the position of at least one opening on the outer periphery of the inner cylinder along axis A. Therefore, at least one opening on the bottom side of the outer cylinder and at least one opening on the outer periphery of the inner cylinder can coincide with each other. When the inner cylinder rotates and air in the inner cylinder exits through at least one opening on the outer periphery of the inner cylinder, air can therefore exit the outer cylinder through at least one opening on the bottom of the outer cylinder. This is advantageous because it enhances the controllability of the process airflow through the rotary drum dryer. As mentioned, the first and second sealing devices can seal the inner and outer cylinders, so the process airflow can only exit the inner cylinder through at least one opening on the outer periphery of the inner cylinder and exit the outer cylinder through at least one opening on the bottom of the outer cylinder. Therefore, the process airflow can be advantageously controlled.

[0028] According to an exemplary embodiment of this disclosure, at least one opening on the bottom side of the outer cylinder extends along a substantially uniform length L. For example, if at least one opening on the outer periphery of the inner cylinder is one of a plurality of openings continuously arranged along length L around the outer periphery surface of the inner cylinder, at least one opening on the bottom of the outer cylinder may have a substantially uniform length L along axis A. The opening on the bottom of the outer cylinder may have a substantially rectangular shape and be arranged in the outer periphery surface of the outer cylinder. The opening on the bottom of the outer cylinder may extend only along a portion of the outer periphery of the outer cylinder, and therefore is not continuously arranged around the outer periphery of the outer cylinder.

[0029] According to an exemplary embodiment of this disclosure, the rotary dryer further includes a drive mechanism for rotating the inner drum. This is advantageous because it provides a means of controlling the speed of the inner drum. Furthermore, due to the centripetal force acting on the clothing inside the inner drum as it rotates, the rotation of the inner drum helps to expel moisture from the clothing via a process airflow exiting the inner drum through at least one opening on the outer periphery of the inner drum. The outer drum may be fixed relative to the inner drum and therefore does not rotate while the inner drum rotates.

[0030] According to an exemplary embodiment of this disclosure, the drive device is a motor. The motor may be connected to a belt drive mechanism arranged around the outer periphery of the inner cylinder. In another example, the motor may be connected to a pulley engaged with a central pin in the inner cylinder. It should be understood that other types of motor arrangements are also possible. Due to the advantageous arrangement of the first and second sealing devices, the size of the motor can be advantageously reduced. This further means that the size of the rotary drum dryer can be reduced due to the smaller space required for the internal components.

[0031] According to one exemplary embodiment of the present disclosure, the drive device is arranged on the top side of the outer cylinder. The top side may correspond to the side of the outer cylinder opposite to the bottom side. Furthermore, when the outer cylinder is arranged in the rotary dryer 100, the top side of the outer cylinder can be considered as the side of the outer cylinder above axis A. The drive device may be further arranged on the top side of the outer cylinder, adjacent to the second end of the outer cylinder. Therefore, the drive device may be arranged on the top side of the outer cylinder, facing the rear side of the rotary dryer. Similarly, the drive device may be arranged on the top side of the outer cylinder, adjacent to the first end of the outer cylinder. Therefore, the drive device may be arranged on the top side of the outer cylinder, facing the front side of the rotary dryer. According to another exemplary embodiment of the present disclosure, the drive device is arranged on the bottom side of the outer cylinder. When the outer cylinder is arranged in the rotary dryer 100, the bottom side of the outer cylinder can be considered as the side of the outer cylinder below axis A. The drive device may be arranged on the bottom side of the outer cylinder, adjacent to the second end of the outer cylinder. Therefore, the drive unit can be arranged on the bottom side of the outer cylinder, facing the rear of the rotary dryer. Similarly, the drive unit can be arranged on the bottom side of the outer cylinder, adjacent to the first end of the outer cylinder. Therefore, the drive unit can be arranged on the bottom side of the outer cylinder, facing the front of the rotary dryer.

[0032] Furthermore, the drive unit can be arranged behind the outer cylinder along axis A, thus located on the rear side of the rotary dryer. Alternatively, the drive unit can be arranged on the top side of the outer cylinder, located behind it along axis A. Or, the drive unit can be arranged on the bottom side of the outer cylinder, also located behind it along axis A. The rotary dryer may include a housing, thus leaving space behind the outer cylinder for arranging other components, such as the drive unit. The possibility of arranging the drive unit in different ways facilitates assembly, increases the flexibility of the rotary dryer, and enhances its adaptability to various situations. Attached Figure Description

[0033] Exemplary embodiments will now be described in more detail with reference to the following figures, in which: Figure 1 A perspective view of a rotary drum dryer according to an exemplary embodiment of the present disclosure is shown schematically. Figure 2 An inner cylinder arranged in a rotary dryer according to an exemplary embodiment of the present disclosure is shown schematically. Figure 3 A front view of a rotary drum dryer according to an exemplary embodiment of the present disclosure is shown schematically. Figures 4a to 4b A cross-sectional view of the outer cylinder and the inner cylinder according to an exemplary embodiment of the present disclosure is shown schematically. Figure 5A perspective view of an inner cylinder according to an exemplary embodiment of the present disclosure is shown schematically; Figure 6 A front view of the inner cylinder is schematically shown according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0034] As shown in the accompanying drawings, the sizes of elements and areas may be exaggerated for illustrative purposes and are therefore provided to illustrate the overall structure of the embodiment. Throughout the text, the same reference numerals refer to the same elements.

[0035] Exemplary embodiments will now be described more fully below with reference to the accompanying drawings, in which presently preferred embodiments are illustrated. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to achieve thoroughness and completeness and to fully convey the scope of the invention to those skilled in the art.

[0036] refer to Figure 1 This illustration shows a rotary dryer 100 according to an exemplary embodiment of the present disclosure. The rotary dryer 100 has a front side 101 and a rear side 102. The rotary dryer 100 further includes a housing 120 that surrounds its internal components and provides a protective enclosure. The rotary dryer 100 further includes a user interface 130, such as a touchscreen. The user interface 130 provides a means for the user of the rotary dryer 100 to start / stop the rotary dryer 100 or to select between different drying programs. A door 110 is provided on the front side 101 of the rotary dryer 100. The door 110 is arranged on the front side 101 by a hinge 103. The door 110 has a circular shape and... Figure 1 The inner drum is shown in the closed position. Door 110 can also be opened using hinge 103. Door 110 can open outwards away from the inner drum (not shown). When door 110 is open, it allows the user to access the inner drum, in which clothing can be placed for drying. Furthermore, when the rotary dryer 100 has finished drying the clothing, the user can remove the clothing from the inner drum through the open door.

[0037] refer to Figure 2The diagram shows a cross-section through a rotary dryer 100 according to an embodiment of the present disclosure. The rotary dryer 100 may be a heat pump rotary dryer 100, which includes a heat pump assembly (not shown). The heat pump may be arranged in a space 121 behind the inner drum 200 and the outer drum 300. In the heat pump rotary dryer, the process air for drying clothes may circulate primarily within the housing 120 of the rotary dryer 100 in a closed loop, but some air exchange with the outside may occur. As mentioned, wet clothes are placed in the inner drum (not shown) of the rotary dryer 100, and as the inner drum rotates, a process airflow is fed through the inner drum to dry the clothes. For example, the process airflow is generated by a blower or fan, which may be located in a space 122 below the inner drum 200 and the outer drum 300. The heat pump may include an evaporator, a compressor, a condenser, and an expansion valve (not shown). As is well known, the compressor forces the refrigerant medium through the heat pump assembly, and the refrigerant medium collects energy in the evaporator, which is then released in the condenser. Figure 2 As shown, the process airflow 240 is achieved through an inner cylinder 200, from which hot, humid air is drawn by a fan assembly (not shown). The process airflow 240 exits the inner cylinder 200 through at least one opening 230 and passes through a filter assembly before reaching the fan assembly located in the space 122 below the inner cylinder 200. Thus, the process airflow 240 can flow through the filter assembly before reaching the fan assembly and then to the evaporator (not shown). The evaporator cools the process airflow, causing the moisture in the process airflow to condense into liquid water. This water can be collected in the bottom section 123 of the rotary dryer 100 and can be discharged from the bottom section through a pipe (not shown). A compressor can be provided to obtain a heat pump flow. The now cooler process airflow 240, containing less water, is then passed to the space 121 on the rear side of the rotary dryer 100 and subsequently passes through a condenser, which reheats the process airflow 240. Then, the heated drying process airflow 240 is reintroduced into the inner cylinder through at least one opening (not shown) on the second end 202 of the inner cylinder 200.

[0038] Continue to refer to Figure 2An outer cylinder 300 and an inner cylinder 200 are arranged in a rotary dryer 100. The outer cylinder 300 has a cylindrical body with a first end 301 and a second end 302, extending along axis A. The first end 301 is located in the front side 101 of the rotary dryer 100, and the second end 302 is located in the rear side 102 of the rotary dryer 100. The outer cylinder 300 is arranged around and surrounds the inner cylinder 200. The inner cylinder 200 has a cylindrical body with a first end 201 and a second end 202, extending along axis A. The inner cylinder 200 is rotatable about axis A and rotates during the drying cycle to dry clothes placed in the inner cylinder. The outer cylinder 300 is fixed relative to the inner cylinder 200. The first end 201 is located on the front side 101 of the rotary dryer 100 and is an open end. Therefore, the inner cylinder 200 is hollow. The first end 201 of the inner cylinder 200 coincides with the door 110, allowing access to the inner cylinder 200 when the door 110 is open. Further, the second end 202 of the inner cylinder 200 is a closed end. The length of the housing 120 exceeds the length of the inner cylinder 200, forming a space 121 behind the second end 202 of the inner cylinder 200 on the rear side of the rotary dryer 102. For example, space 121 can be used as a enclosure for an air duct (not shown), a heat pump unit (not shown), a fan assembly (not shown), or as a enclosure for a drive unit for the fan assembly or the inner cylinder 200. A further space 122 exists within the housing 120 below the inner cylinder 200. For example, space 122 can be used as a enclosure for an air duct (not shown), a heat pump unit (not shown), a fan assembly (not shown), or as a enclosure for a drive unit for the fan assembly or the inner cylinder 200. A drive unit 400 is arranged in the space above the outer cylinder 300 to drive the inner cylinder 200 to rotate. The drive unit is a motor 400 connected to a belt 401. The belt 401 is arranged around the inner cylinder 200 and passes through an opening (not shown) on the top side of the outer cylinder 300. The motor 400 can be attached to a partition wall 402 arranged in the second end 302 of the outer cylinder 300. One side of the partition wall 402 is attached to the bottom side of the housing 120, and the other side of the partition wall is attached to the top side of the housing 120, thereby forming a partition between the outer cylinder 300, the inner cylinder 200, and the space 121. At least one opening 230 is arranged around the outer periphery of the inner cylinder 200, and there are multiple openings 230. The openings 230 are arranged in a rectangular shape around the outer periphery of the inner cylinder 230 and extend for a length L along the cylindrical body of the inner cylinder 200. Therefore, the air leaving the inner cylinder 200 may eventually enter the space 122 below the inner cylinder 122. Thus, a fan assembly (not shown) can be placed in this space to generate a process airflow 240 and recirculate the air from the inner cylinder 200 back into the inner cylinder 200 via a heat pump unit (not shown).

[0039] refer to Figure 3 The image shows a front view of a rotary dryer 100 according to an exemplary embodiment of the present disclosure. Figure 3 The drum dryer 100 is shown in cross-section, with the front side 101 of the drum dryer 100 removed. A motor 400 is shown attached to a partition wall 402. The motor 400 is positioned at the center of the width W of the drum dryer 100. Furthermore, the motor 400 is aligned with the center C of the inner drum 200 and / or the outer drum 300 in the width direction of the drum dryer 100. A belt 401 is arranged around the outer periphery of the inner drum 200.

[0040] refer to Figure 4a The diagram shows a cross-sectional view of an inner cylinder 200 and an outer cylinder 300 according to an exemplary embodiment of the present disclosure. The outer cylinder 300 surrounds the inner cylinder 200. The outer cylinder has a cylindrical body with a first end 301 and a second end 302, wherein the first end 301 is disposed in the front side 101 of the rotary dryer 100. The second end 302 of the outer cylinder 300 is disposed in the rear side 102 of the rotary dryer 100. The first end 301 of the outer cylinder 300 is an open end, meaning that the outer cylinder 300 is hollow, and the inner cylinder 200 is fitted into the hollow space inside the outer cylinder. A door 110 is disposed in the front side 101 of the rotary dryer 100. The front side 101 of the rotary dryer 100 also has an open end, which at least partially coincides with the open end of the first end 301 of the outer cylinder 300. Therefore, when the door 110 is open, it allows access to the inner cylinder 200 via the outer cylinder 300 and the front side 101 of the rotary dryer. The size of the open end of the inner cylinder 200 may be the same as the size of the open end of the outer cylinder 300. The size of the open end of the inner cylinder 200 may further be the same as the size of the open end of the front side 101 of the rotary dryer 100. The door 110 is sealed by a first sealing device 310. The first sealing device 310 is arranged on the surface 111 of the door 110 facing the front side 101 of the rotary dryer 100. The first sealing device 310 is arranged on the surface 111 around the outer periphery of the door 110. Alternatively, the first sealing device 310 is arranged on the front side 101 of the rotary dryer 100, on the surface of the front side of the rotary dryer facing the door 110. The first sealing device 310 is arranged around the open end of the front side 101 of the rotary dryer 100.

[0041] Furthermore, the space between the inner cylinder 200 and the outer cylinder 300 is sealed by a second sealing device 210. The second sealing device 210 is arranged on the first end 201 of the inner cylinder 200 and the first end 301 of the outer cylinder 300, and also on the second end 202 of the inner cylinder 200 and the second end 302 of the outer cylinder 300. The second sealing device 210 is arranged in the space between the inner cylinder 200 and the outer cylinder 300. The second sealing device 210 is arranged around the outer periphery of the first end 201 and the outer periphery of the second end 202 of the inner cylinder 200. The second sealing device 210 is arranged on the surface 211 of the first end 201 or the second end 202 of the inner cylinder 200, both of which face the outer cylinder 300. Alternatively, the second sealing device 210 is arranged on the surface 311 of the outer cylinder 300 facing the inner cylinder 200. This shows openings 230 on the outer periphery of the inner cylinder 200, which are arranged on the cylindrical body of the inner cylinder 200 facing the first end 201 of the inner cylinder 200.

[0042] In addition, the outer cylinder 300 includes an opening 320 disposed on the bottom 303 of the outer cylinder 300. The opening 320 coincides with a plurality of openings 230 on the inner cylinder 200.

[0043] Furthermore, at least one opening 220 is shown on the second end 202 of the inner cylinder 200. The at least one opening 220 is a plurality of openings 220 distributed on the surface of the second end 202 of the inner cylinder 200. The outer cylinder 300 has an opening 330 arranged on its second end 302. The opening 330 coincides with at least some of the plurality of openings 220 on the inner cylinder 200. Figure 2 As shown, opening 330 can be connected to space 121 in housing 120 of rotary dryer 100. Process airflow 240 enters inner cylinder 200 and flows through inner cylinder 200 in a semi-axial path. Process airflow 240 flows into inner cylinder 200 through opening 330 on second end 302 of outer cylinder 300 and multiple openings 220 on second end 202 of inner cylinder 200. Process airflow 240 then flows out of inner cylinder 200 through multiple openings 230 on outer periphery of inner cylinder 200 and openings 320 on bottom 303 of outer cylinder 300. Second end 302 of outer cylinder 300 is perpendicular to bottom 303 of outer cylinder 300.

[0044] Furthermore, a drive unit 400 is arranged above the inner cylinder 200 and the outer cylinder 300. The drive unit 400 is a motor connected to the inner cylinder 200, so that the rotation of the inner cylinder 200 can be driven by the motor 400. More specifically, the motor 400 is connected via a belt drive mechanism 401 surrounding the inner cylinder 200. The motor 400 is arranged on the top of the outer cylinder 300. The belt drive mechanism 401 is arranged around the outer periphery of the inner cylinder 200 through an opening in the outer cylinder 300.

[0045] refer to Figure 4b The diagram shows a cross-sectional view of the inner cylinder 200 and the outer cylinder 300 according to an exemplary embodiment of the present disclosure. Figure 4b The second sealing device 210 is a labyrinth seal 210. The labyrinth seal is arranged on the first end 201 and the second end 202 of the inner cylinder 200 and the first end 301 and the second end 302 of the outer cylinder 300. A portion of the labyrinth seal 210 is arranged on surface 211 of the inner cylinder 200, and the remaining portion of the labyrinth seal 210 is arranged on surface 311 of the outer cylinder 300, wherein surfaces 211 and 311 face each other. (As shown from...) Figure 4b It can be seen that the portions of the labyrinth seals arranged on the corresponding surfaces 211 and 311 are not adjacent to each other. This may make the labyrinth seal 210 frictionless. If air is to be able to escape from the labyrinth seal 210, the air needs to escape through the path formed by the space between the labyrinth seals 210 on the corresponding surfaces 211 and 311. Figure 4b As seen, the labyrinth seal 210 has a toothed shape.

[0046] refer to Figure 5 This diagram shows a perspective view of an inner cylinder 200 according to an exemplary embodiment of the present disclosure. The inner cylinder 200 is shown from a first end 201, which corresponds to the front side 101 of the rotary drum dryer 100. Here, the surface 211 of the inner cylinder 200 is shown as an annular section with an opening formed on the inner cylinder 200. Inside the inner cylinder 200, a plurality of openings 220 are visible. The plurality of openings 220 are arranged on the surface of a second end 202 of the inner cylinder 200. Further, a plurality of openings 230 arranged around the outer periphery of the inner cylinder 200 are shown. The plurality of openings 230 arranged on the outer periphery of the inner cylinder 200 are divided into a plurality of segments, each segment being shaped as a rectangle.

[0047] refer to Figure 6The diagram shows a front view of an inner cylinder 200 according to an exemplary embodiment of the present disclosure. The inner cylinder 200 is shown from its first end 201, which corresponds to the front side 101 of the rotary drum dryer 100. A plurality of openings 220 on the second end 202 of the inner cylinder 200 are distributed on the surface of the second end 202. Furthermore, the radial direction R, i.e., the direction in which process air flows out from the first end 201 of the inner cylinder 200, is shown.

[0048] Although the features and elements are described above in specific combinations, each feature or element can be used alone without other features and elements, or in various combinations with or without other features and elements.

[0049] Furthermore, when practicing the claimed invention based on a study of the accompanying drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement other variations of the disclosed embodiments. In the claims, the word "comprising" does not exclude other elements, and the indefinite articles "a" or "an" do not exclude a plurality. The simple fact that certain features are referenced in mutually different dependent claims does not indicate that combinations of these features cannot be used advantageously.

Claims

1. A rotary drum dryer (100) having a front side (101) and a rear side (102), the rotary drum dryer (100) comprising: A rotatable inner cylinder (200) having a circular cross-section and extending along axis A, the inner cylinder (200) having a first end (201) and a second end (202), wherein the first end (201) is arranged on the front side (101) of the rotary drum dryer (100); A fixed outer cylinder (300) is arranged coaxially with and surrounds the inner cylinder (200). The outer cylinder (300) has a first end (301) and a second end (302), wherein the first end (301) is arranged on the front side (101) of the rotary drum dryer (100). A door (110) is located on the front side (101) of the rotary dryer (100) and is configured to allow access to the inner cylinder (200). A first sealing device (310) is configured to seal the space between the front side (101) of the rotary dryer (100) and the door (110), wherein the first sealing device (310) is disposed on the surface (111) of the door (110) facing the front side (101) of the rotary dryer (100) or on the front side (101) of the surface (111) of the rotary dryer (100) facing the door (110); A second sealing device (210) is configured to seal the space between the inner cylinder (200) and the outer cylinder (300). The second sealing device (210) is disposed on at least one surface (211) of the inner cylinder (200) facing the outer cylinder (300), and alternatively disposed on at least one surface (311) of the outer cylinder (300) facing the inner cylinder (300). A fan assembly arranged to generate a process airflow (240) passing through the inner cylinder (200); wherein, The process airflow (240) enters the inner cylinder (200) through at least one opening (220) on the second end (202) of the inner cylinder (200) and exits the inner cylinder (200) in the radial direction (R) through at least one opening (230) on the outer periphery of the inner cylinder (200).

2. The rotary drum dryer (100) according to claim 1, wherein, The bottom side (303) of the outer cylinder (300) includes at least one opening (320), the bottom side (303) being perpendicular to the first end (301).

3. The rotary drum dryer (100) according to claim 2, wherein, The position of the at least one opening (320) on the bottom side (303) of the outer cylinder (300) corresponds to the position of the at least one opening (230) on the outer periphery of the inner cylinder (200) along axis A.

4. The rotary drum dryer (100) according to any one of the preceding claims, wherein, The outer cylinder (300) further includes at least one opening (330) disposed on the second end (302) of the outer cylinder, the at least one opening (330) being arranged to be aligned with at least one opening (220) on the second end (202) of the inner cylinder (200).

5. The rotary drum dryer (100) according to any one of the preceding claims, wherein, At least one opening (220) on the second end (202) of the inner cylinder (200) is a plurality of openings.

6. The rotary dryer (100) according to any one of the preceding claims, wherein, The at least one opening (230) around the outer periphery of the inner cylinder (200) is a plurality of openings distributed along the axis A along the length L on the inner cylinder (200).

7. The rotary drum dryer (100) according to claims 3 and 6, wherein, The at least one opening (320) on the bottom side (303) of the outer cylinder (300) extends along substantially the same length L.

8. The rotary drum dryer (100) according to any one of the preceding claims, wherein, The first sealing device (310) is a gasket.

9. The rotary drum dryer (100) according to any one of the preceding claims, wherein, The second sealing device (210) is arranged on the first end (201) and the second end (202) of the inner cylinder (200) and on the surface (211) facing the outer cylinder (300), or alternatively on the first end (301) and the second end (302) of the outer cylinder (300) and on the surface (311) facing the inner cylinder (300).

10. The rotary drum dryer (100) according to any one of the preceding claims, wherein, The second sealing device (210) is a gasket that is continuously arranged on the surface facing the outer cylinder (300) around the outer periphery of the inner cylinder (200).

11. The rotary drum dryer (100) according to any of the preceding claims, wherein, The second sealing device (210) is a labyrinth seal comprising two mating washers, wherein the first washer is disposed on the inner cylinder (200) and the second washer is disposed on the outer cylinder (300).

12. The rotary drum dryer (100) according to any of the preceding claims further includes a drive device (400) for driving the rotation of the inner drum (200).

13. The rotary drum dryer (100) according to claim 12, wherein, The drive unit (400) is a motor.

14. The rotary drum dryer (100) according to claim 12 or 13, wherein, The drive unit is located on the top side of the outer cylinder (300).

15. The rotary drum dryer (100) according to any one of the preceding claims, wherein, The outer cylinder (300) has a circular cross-section.

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