A TUMBLE DRYER

Abstract

 Disclosed herein is a tumble dryer (100) having a front (101) and a rear side (102), the tumble 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 (201) and a second end (202), wherein the first end (201) is arranged in the front side (101) the tumble dryer (100), a fixed outer drum (300) coaxially arranged with the inner drum (200) and enclosing said inner drum (200), the outer drum (300) having a first (301) and a second end (302), wherein the first end (301) is arranged in the front side (101) the tumble dryer (100). The tumble dryer further comprises a first (310) and a second (210) sealing means.

Description

Technical Field

[0001] The present invention relates to the technical field of tumble dryers.

Background

[0002] Tumble dryers are an important keystone within the laundry industry, both in professional environments such as hotels, hospitals or laundromats, as well as in private environments such as people's homes. A conventional tumble dryer typically operates by continuously drawing in ambient air from the surrounding environment, heating it and then leading it through a drum where the wet laundry is placed. The heated air removes the moisture from the wet laundry and exits the drum as hot, humid air. The hot, humid air is sometimes vented outside the dryer to the surrounding environment, to make space for new air to be drawn into the drying process.

[0003] Thus, in some way or another, a tumble dryer has to deal with large quantities of humid air and it is therefore of great importance to ensure that the humid air is handled properly, to avoid damage of some of the internal parts of the dryer. It is well known that humid air increases the risk of corrosion, could cause shortcuts in electrical components, and further pose a safety risk for a user if the hot humid air exits the dryer near the user.

[0004] A decreased drying performance is another problem that could occur as a result of process air leaking from the drum in an undesired way. The hot air may leak from the drum before it is fully saturated with water vapor, thus decreasing the drying effect. The drying process thus requires a larger flow of air, and in some cases also prolongs the duration of the drying process.

[0005] Some of these problems can be mitigated by sealing the drum, to force the hot, humid air to exit the drum along a desired path. Some examples of seals are gaskets of various design and materials, arranged between the drum and other internal components of the tumble dryer. However, the introduction of gaskets may also mean the introduction of unwanted friction between the internal components, which has to be accounted for in the operation of the tumble dryer.

Summary

[0006] In light of the above, it is desired to provide alternate solutions in order to overcome the problems of handling hot, humid air and avoiding the effects from an unwanted friction. These and other objects are achieved by providing an improved tumble dryer and in particular an improved drum arrangement having the features in the independent claims. Preferred embodiments are defined in the dependent claims.

[0007] Hence, according to a first aspect of the present invention, there is provided a tumble dryer having a front and a rear side, the tumble dryer comprising a rotatable inner drum having a circular cross section and extending along an axis A, the inner drum having a first and a second end, wherein the first end is arranged in the front side the tumble dryer. The tumble dryer further comprises a fixed outer drum coaxially arranged with the inner drum and enclosing said inner drum, the outer drum having a first and a second end, wherein the first end is arranged in the front side the tumble dryer. Furthermore, the tumble dryer comprises a door arranged in the first end of the outer drum, and configured to allow access to the inner drum, and a first sealing means configured to seal a space between the first end of the outer drum and the door, wherein the first sealing means is arranged on a surface of the door facing the first end of the outer drum or on the first end of the drum facing the surface of the door. There is further a second sealing means configured to seal a space between the inner drum and the outer drum, the second sealing means arranged on at least one surface of the inner drum facing the outer drum alternatively on at least one surface of the outer drum facing the inner drum. The tumble dryer further comprises a fan arrangement arranged to generate a flow of process air through the inner drum, wherein the flow of process air enters the inner drum through at least one opening in the second end of the inner drum, and exits the inner drum in a radial direction through at least one opening in the periphery of the inner drum.

[0008] There are a number of advantages associated with tumble dryer according to the present invention. For example, the air path of the flow of process air may advantageously be controlled by the placements of the openings in the inner drum, such that the flow of process air is led in a desired direction through the inner drum, and that it exits the drum in a controlled way. By doing so, the drying efficiency of the tumble dryer is increased due to less leakage of air.

[0009] The outer drum may enclose the inner drum such that a gap is formed between the inner drum and the outer drum. The distance between the outer drum and the inner drum forming the gap may be the same along the lengths of the outer and inner drum, as along the first and second ends of the outer and inner drums.

[0010] According to one exemplifying embodiment of the present disclosure, the outer drum has a circular cross section. The inner and outer drum may have a cylindrical shape with a cylindrical body having a first end and a second end. The first end may correspond to the front side of the tumble dryer, and the second end may correspond to the rear side of the tumble dryer. The inner drum and the outer drum may be made from a metal, for example aluminum or stainless steel. The inner drum and outer drum may further be formed from another material, suitable for providing a thermal insulation. For example, the outer drum may be formed from a thermally insulating material for maintaining the heat within the tumble dryer and, more specifically, within the inner drum. Similarly, the inner drum may be formed from a thermally insulating material for maintaining the heat from the process air inside the inner drum, increasing the drying effect of the process air inside the inner drum. Even further, the outer and inner drums may be formed from a metal material, comprising a sleeve of thermally insulating material, to combine the effects of a durable material together with thermally insulating properties. Thus, circular cross section of the outer drum may have a larger diameter than the circular cross section of the inner drum, such that the outer drum may enclose the inner drum. The outer drum may fully enclose the inner drum. A double drum configuration allows a better sealing of the inner drum, and the tumble dryer. Further, a double drum configuration where the outer drum encloses the inner drum is advantageous in avoiding that air and/or moisture leaks from the inner drum to other components of the tumble dryer. A further advantage is that the double drum configuration allows for an increased thermal insulation which allows higher temperatures inside the inner drum while drying laundry placed therein.

[0011] Furthermore, the door of the tumble dryer may be arranged in the first end of the outer drum. The door may be installed with hinges enabling opening and closing of the door. The outer drum may have an opening in the first end thereof which is covered by the door when the door is closed. The opening in the outer drum may thus be uncovered when the door is opened. The inner drum may have an opening in the first end thereof, coinciding with the opening in the outer drum, allowing access to the inner drum. Thus, when the door is open, it may allow access to the inner drum, though the openings in the outer drum and the inner drum. Thus, the door may be used as a way to allow a user to place laundry in the inner drum, and to remove laundry from the inner drum. A user may for example open the door, load the inner drum with laundry, close the door, start a drying program, and when the drying program is finished, open the door, unload the dry laundry, and close the door. The door may have a substantially circular shape, and may thus match the shape of the cross section of the outer and inner drums. The door may have a smaller diameter than the outer drum.

[0012] Furthermore, the first sealing means are arranged to seal a space between the door and the front side of the tumble dryer. This is advantageous since it ensures that no air is leaked through the door during the drying process. The first sealing means may be arranged on a surface of the front side of the tumble dryer, facing the door. Alternatively, the first sealing means may be arranged on a surface of the door facing the front side of the tumble dryer. According to one exemplifying embodiment of the present disclosure, the first sealing means is a gasket. The first sealing means may be made from a ductile material such as a type of rubber. For example, if the door is circular, the first sealing means may be a gasket arranged on the door around a periphery thereof, such that when the door is closed, the gasket abuts the front side of the tumble dryer. Thus, the first sealing means may be pressed between the door and the front side of the tumble dryer upon closing the door, such that the ductile material is compressed, thereby sealing the space. The same result may be achieved by arranging the gasket on the front side of the tumble dryer, on a surface thereof facing the door. The gasket may have a shape matching the circular cross section of the door. Further, the first sealing means may be arranged around an opening in the front side of the tumble dryer, which may also have a circular shape. The front side of the tumble dryer may have an opening, where the outer drum may be fitted. Thus, the opening in the front side of the tumble dryer may have the same size as the diameter of the outer drum, such that the outer drum may fit inside the front side of the tumble dryer.

[0013] Further, the tumble dryer comprises second sealing means arranged to seal a space between the inner drum and the outer drum, and arranged on at least one surface of the inner drum facing the outer drum alternatively on at least one surface of the outer drum facing the inner drum.

[0014] According to one exemplifying embodiment, the second sealing means may be arranged on the first end and the second end of the inner drum on a surface facing the outer drum. Alternatively, the second sealing means may be arranged on the first and second ends of the outer drum, on a surface facing the inner drum. Thus, the second sealing means may be arranged on the first and second ends of the inner drum. The second sealing means may thus consist of two parts, one part arranged on the first end, and one part arranged on the second end. The at least one surface may thus be two surfaces. Since the inner drum has a circular cross-section, the second sealing means may be distributed on the circular surface of the first end and the second end of the inner drum, facing the outer drum. The second sealing means may be distributed to cover the entire surface of the first and second ends of the inner drum. The second sealing means may further be distributed in a ring, following the shape of the surface of the first and second ends. The ring may be arranged towards the edge of the first and second edges of the inner drum. Similarly, the second sealing means may be arranged on a first end and a second end of the outer drum, on a surface facing the inner drum. Thus, the second sealing means may be arranged on the first and second ends of the outer drum, respectively. Since the inner drum has a circular cross-section, the second sealing means may be distributed on the circular surface of the first end and the second end of the outer drum, facing the inner drum. The second sealing means may be distributed to cover the entire surface of the first and second ends of the outer drum. The second sealing means may further be distributed in a ring, following the shape of the surface of the first and second ends. The ring may be arranged towards the edge of the first and second edges of the outer drum. For example, in the example where the second sealing means is arranged on a first and second end of the inner drum, the sealing may fill the gap between the inner and outer drum, and vice versa in the example where the second sealing means is arranged on the first and second ends of the outer drum, on a surface facing the inner drum.

[0015] According to one exemplifying embodiment of the present disclosure, the second sealing means is a gasket continuously arranged around the periphery of the inner drum, on a surface facing the outer drum. Thus, in the example where the inner drum has a cylindrical body with a first and a second end, the second sealing means may be arranged around a periphery, i.e. an outer surface of the cylindrical body of the inner drum. Thus, the at least one surface may in this example correspond to one surface, i.e. the outer surface of the inner drum. The second sealing means may be distributed around the periphery as smaller parts, or a continuous seal around the periphery. Furthermore, the second sealing means may be divided into two parts, one arranged around the periphery of the inner drum towards the first end of the inner drum, and one part arranged around the periphery of the inner drum towards a second end of the inner drum.

[0016] Similarly, according to one exemplifying embodiment of the present disclosure, the second sealing means may be arranged around the periphery of the outer drum, on a surface facing the inner drum. Thus, the at least one surface may in this example correspond to a single surface, i.e. the inner surface of the outer drum facing the inner drum. In the case where the outer drum has a cylindrical shape, this surface corresponds to the inner surface of the cylindrical body of the outer drum. The second sealing means may be distributed around the periphery as smaller parts, or a continuous seal around the periphery. Furthermore, the second sealing means may be divided into two parts, one arranged around the periphery of the outer drum towards the first end of the outer drum, and one part arranged around the periphery of the outer drum towards a second end of the outer drum.

[0017] Furthermore, according to one exemplifying embodiment of the present disclosure, the second sealing means may be arranged on the first and the second end of the inner drum or the outer drum, and around a periphery of the cylindrical body of the inner drum or the outer drum. Thus, the at least one surface may be three surfaces. The second sealing means may thus be divided into a first part arranged on a surface of the first end of the inner drum, facing the outer drum. A second part of the second sealing means may be arranged on a surface of the second end of the inner drum, facing the outer drum. A third part of the second sealing means may be arranged around a periphery of the inner drum, on an outer surface of the cylindrical body of the inner drum facing the outer drum.

[0018] Similarly, the second sealing means may be arranged on the outer drum instead. The second sealing means may then be divided into a first part arranged on a surface of the first end of the outer drum, facing the inner drum. A second part of the second sealing means may be arranged on a surface of the second end of the outer drum, facing the inner drum. A third part of the second sealing means may be arranged around a periphery of the outer drum, on an inner surface of the cylindrical body of the outer drum facing the inner drum.

[0019] The second sealing means may be made from a ductile material such as a type of rubber. Further, the second sealing means may be made from felt, brushes, or a plastic material. For example, a felt material or brushes may decrease the friction between the outer drum and the inner drum, while sealing the space therebetween. A decreased friction between the inner drum and outer drum may be beneficial since it decreases the wear on the second sealing. Further, a decreased friction between the outer drum and the inner, rotating drum is beneficial since it prevents second sealing from impairing the effect of the rotation of the inner drum.

[0020] The second sealing means may thus be advantageously arranged to seal the inner and outer drums, such that the flow of process air travelling through the inner and outer drums is advantageously controlled to flow where it is intended, while preventing it to flow out through openings where it is not intended to flow. The proposed configuration further allows for an increased vacuum pressure effect inside the inner drum, which decreases the water boiling point, and increases the speed of the water evaporation, therefore a faster the remotion of the moisture content from laundry placed in the inner drum. Further, the second sealing means may also facilitate directing of the flow of process air, since they enable an environment where the air leakage is minimized, preventing air to flow in other directions than the intended.

[0021] According to one exemplifying embodiment of the present disclosure, the second sealing means is a labyrinth seal comprising two mating gaskets, wherein the first gasket is arranged on the inner drum, and the second gasket is arranged on the outer drum. The first gasket may thus be arranged on a first and second end of the inner drum, on surfaces thereof facing the outer drum. Likewise, the second gasket may be arranged on a first and second end of the outer drum, on surfaces thereof facing the inner drum. The first and second gaskets may have a shape allowing them to interlock with each other, such as a plurality of grooves. Thus, the labyrinth seal may provide a tortuous path to prevent leakage between the inner drum and the outer drum. For example, the first and second gaskets may have a plurality of teeth-like shape protrusions with grooves therebetween. The grooves and protrusions may be arranged such that a protrusion on the first gasket fits into a groove on the second gasket. Further, the first and second gaskets may have a gap between them in an interlocked state. Thus, there may be a low or no friction between the first and second gaskets. Labyrinth seals may thus advantageously decrease the energy consumption needed in order to rotate the inner drum. Further, a smaller energy consumption also enables the use of a smaller motor to drive the rotation of the inner drum, which increases the sustainability of the tumble dryer.

[0022] Further, the tumble dryer comprises a fan arrangement arranged to generate a flow of process air through the inner drum. The fan arrangement may direct the flow of process air in a desired direction. The fan arrangement may be placed below the outer drum, for example. The fan arrangement may comprise a fan together with a motor driving the fan. The motor may be a gear motor, which enables the fan to be driven with different velocities, thereby controlling the flow of process air. The flow of process air may be a closed loop flow, starting from the fan arrangement where it is generated, and then flowing into the inner drum through the at least one opening in the second end thereof. The flow of process air may thereafter absorb moisture from the laundry placed in the inner drum, then flow out from the inner drum through the at least one opening in the periphery of the inner drum, in a radial direction. The tumble dryer may further comprise a heat pump system for dehumidifying and heating the flow of process air. The flow of process air may thus flow (by being directed by the fan arrangement) through the heat pump system after exiting the inner drum, and then warm, dry air may enter the inner drum again. Thus, the flow of process air may be recirculated through the inner drum until the laundry is dried. The first and second sealing means may thus facilitate the flow of process air generated by the fan arrangement to be maintained within the tumble dryer and prevent it from leaking. This is beneficial since ambient air from an outside of the tumble dryer does not have to be drawn in and risk entering the inner drum in a cold state, decreasing the drying capacity. Further, the fan arrangement is advantageous since it directs the flow of process air in a desired direction, increasing the controllability of the tumble dryer and the drying process. Thus, the fan arrangement allows for the managing of large air flows, which increases the evaporation capacity and the vacuum pressure effect of the flow of process air.

[0023] According to one exemplifying embodiment of the present disclosure, the at least one opening in the second end of the inner drum is a plurality of openings. The plurality of holes may be distributed on a surface of the second end of the inner drum facing the outer drum. This is advantageous since it provides a way for the air to enter the inner drum and dry the laundry placed therein. The plurality of holes may enable for a flow of process air to be distributed over a surface of the second end of the inner drum when it enters the inner drum. In this way, the flow of process air entering the drum is distributed over a volume of the inner drum, and may thus be more evenly distributed over the laundry placed inside the inner drum. This may increase the drying performance by decreasing the drying time, and thus increase the efficiency of the tumble dryer. Further, the plurality of holes distributed over the surface of the second end of the inner drum may also reduce a pressure drop of the flow of process air coming from outside the outer drum and flowing through the plurality of holes. This is beneficial since a reduced pressure drop enables energy savings in the tumble dryer, for example energy savings in the fan arrangement and the heat pump arrangement.

[0024] According to one exemplifying embodiment of the present disclosure, the outer drum further comprises at least one opening arranged in the second end thereof, the at least one opening is arranged to align with the at least one opening in the second end of the inner drum. Thus, the second end of the outer drum may also have an opening arranged therein, on a surface facing the second end of the inner drum. The at least one opening in the second end of the outer drum may further coincide with an inlet for an air duct leading from the fan arrangement to the second end of the outer drum. The outer drum may be connected to an air duct which is led down on a rear side of the tumble dryer, behind the inner and outer drum and coupled to a heat pump unit or similar, for heating and dehumidifying the flow of process air drying the laundry in the inner drum. This is advantageous since the outer drum encloses the inner drum, and thus the opening in the second end of the outer drum together with the at least one opening in the second end of the inner drum forms an enclosed path for the flow of process air to flow in.

[0025] According to one exemplifying embodiment of the present disclosure, the at least one opening around the periphery of the inner drum is a plurality of openings distributed along a length L on the inner drum along the axis A. Put in other words, the at least one opening in the periphery of the inner drum may be a plurality of holes distributed on a peripheral surface of the inner drum. In one example, the length L may correspond to 50% of the length of the inner drum. In another example, the length L may correspond to 25% of the length of the inner drum. It will be appreciated that the plurality of holes extending along the length L may correspond to a shorter portion of the length of the inner drum, or to a larger portion of the length of the inner drum. Having a plurality of openings distributed along a length L is advantageous since it provides a way for the flow of process air to exit the inner drum when the air has absorbed moisture from the laundry. The plurality of holes may enable for a flow of process air to be distributed over an increased surface of the laundry placed in the inner drum, and over the surface of the periphery of the inner drum when it exits the inner drum. This allows for new, hot air to enter the inner drum, increasing the efficiency of the tumble dryer.

[0026] According to one exemplifying embodiment of the present disclosure, the outer drum comprises at least one opening on a bottom side thereof, the bottom side being perpendicular to the first end. Thus, in the case where the outer drum is cylindrical, the at least one opening in the second end of the outer drum may be arranged in the periphery of the cylindrical body of the outer drum. Thus, the at least one opening in the second end of the outer drum may be arranged on a surface of the second end, a side perpendicular to the bottom side of the outer drum. This is advantageous in that the flow of process air may be led into the inner drum in a direction parallel to the axis A, and led out from the drum in a radial direction on the bottom side of the outer drum. Thus, the flow of process air flowing through the inner drum may do so in a semi-axial direction. The semi-axial direction is beneficial since it enables a turbulent flow of process air to occur in the inner drum. A turbulent flow of process air may be distributed over an increased volume of the inner drum, thus reaching more laundry placed therein, increasing the drying effect of the tumble dryer.

[0027] According to one exemplifying embodiment of the present disclosure, a position of the at least one opening on the bottom side of the outer drum corresponds to a position of the at least one opening in the periphery of the inner drum, along axis A. The at least one opening on the bottom side of the outer drum and the at least one opening in the periphery of the inner drum may thus coincide with each other. When the inner drum rotates and the air therein exits the inner drum through the at least one opening in the periphery thereof, it may thus exit the outer drum through the at least one opening in the bottom thereof. This is advantageous since it increases the controllability of the flow of process air flowing through the tumble dryer. As mentioned, the first and second sealing means may seal the inner and outer drums, why the flow of process air may only exit the inner and exit the outer drum through the at least one opening in the periphery of the inner drum and the at least one opening in the bottom of the outer drum. Thus, the flow of process air may be advantageously controlled.

[0028] According to one exemplifying embodiment of the present disclosure, the at least one opening in the bottom side of the outer drum extends along substantially the same length L. If, for example, the at least one opening in the periphery of the inner drum is a plurality of openings continuously arranged around the peripheral surface of the inner drum along a length L, the at least one opening in the bottom of the outer drum may have substantially the same length L along the axis A. The opening in the bottom of the outer drum may have a substantially rectangular shape and be arranged in a peripheral surface of the outer drum. The opening in the bottom of the outer drum may only extend along a portion of the periphery of the outer drum, thus not be continuously arranged around the periphery of the outer drum.

[0029] According to one exemplifying embodiment of the present disclosure, the tumble dryer further comprises a driving means for driving the rotation of the inner drum. This is advantageous in that it provides a way to control a velocity of the inner drum. Further, a rotation of the inner drum helps pressing the humidity out from the laundry via the flow of process air that exits the inner drum through the at least one opening in the periphery of the inner drum, due to the centripetal force acting on the laundry placed inside the inner drum when the inner drum is rotating. The outer drum may be fixed relative the inner drum, and thus not rotate when the inner drum rotates.

[0030] According to one exemplifying embodiment of the present disclosure, the driving means is a motor. The motor may be connected to a belt gear arranged around the periphery of the inner drum. In another example, the motor may be connected to a pulley coupled to a center pin in the inner drum. It will be appreciated that other types of motor arrangements are also possible. The size of the motor may be advantageously reduced due to the advantageous arrangement of the first and second sealing means. This further means that a size of the tumble dryer may be reduced due the components requiring a smaller space therein.

[0031] According to one exemplifying embodiment of the present disclosure, the driving means is arranged on a top side of the outer drum. The top side may correspond to a side of the outer drum, opposite to the bottom side. Moreover, the top side of the outer drum may be regarded as the side of the outer drum above the axis A, when the outer drum is arranged in the tumble dryer 100. The driving means may further be arranged on a top side of the outer drum, adjacent the second end thereof. Thus, the driving means may be arranged on a top side of the outer drum towards the rear side of the tumble dryer. Similarly, the driving means may be arranged on a top side of the outer drum, adjacent the first end thereof. Thus, the driving means may be arranged on a top side of the outer drum towards the front side of the tumble dryer. According to another exemplifying embodiment of the present disclosure, the driving means is arranged on a bottom side of the outer drum. The bottom side of the outer drum may be regarded as the side of the outer drum below the axis A, when the outer drum is arranged in the tumble dryer 100. The driving means may be arranged on a bottom side of the outer drum, adjacent the second end thereof. Thus, the driving means may be arranged on a bottom side of the outer drum towards the rear side of the tumble dryer. Similarly, the driving means may be arranged on a bottom side of the outer drum, adjacent the first end thereof. Thus, the driving means may be arranged on a bottom side of the outer drum towards the front side of the tumble dryer.

[0032] Even further, the driving means may be arranged behind the outer drum, in a direction along axis A, thus in the rear side of the tumble dryer. The driving means may be arranged on a top side of the outer drum, behind the outer drum in a direction along axis A. The driving means may be arranged on a bottom side of the outer drum, behind the outer drum in a direction along axis A. The tumble dryer may comprise a housing, leaving some space behind the outer drum for arranging other components, such as the driving means for example. The possiblity to arrange the driving means in different ways facilitates assembling, increases the flexibility of the tumble dryer and adaptability to different situations.

Brief Description of the Drawings

[0033] Exemplifying embodiments will now be described in more detail, with reference to the following appended drawings, in which:

Figure 1 schematically illustrates a perspective view of a tumble dryer according to an exemplifying embodiment of the present disclosure;

Figure 2 schematically illustrates an inner drum arranged in a tumble dryer according to an exemplifying embodiment of the present disclosure;

Figure 3 schematically illustrates a front view of a tumble dryer according to an exemplifying embodiment of the present disclosure;

Figures 4a-4b schematically illustrates cross-sectional views of an outer and an inner drum according to exemplifying embodiments of the present disclosure;

Figure 5 schematically illustrates a perspective view of an inner drum according to an exemplifying embodiment of the present disclosure;

Figure 6 schematically illustrates a front view of an inner drum according to an exemplifying embodiment of the present disclosure.

Detailed Description

[0034] As illustrated in the figures, the size of the elements and regions may be exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of the embodiments. Like reference numerals refer to like elements throughout.

[0035] Exemplifying embodiments will now be described more fully hereinafter with reference to the accompanying figures, in which currently preferred embodiments are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0036] With reference to figure 1, a tumble dryer 100 according to an exemplifying embodiment of the present disclosure is shown. The tumble dryer 100 has a front side 101, and a rear side 102. The tumble dryer 100 further comprises a housing 120 enclosing the internal components thereof, and providing a protective shell. The tumble dryer 100 further comprises a user interface 130, for example a touch screen. The user interface 130 provides a way for a user of the tumble dryer 100 to start/stop the tumble dryer 100, or to select amongst different drying programs. In the front side 101 of the tumble dryer 100, there is a door 110. The door 110 is arranged in the front side 101 with hinges 103. The door 110 has a circular shape and is shown in a closed state in figure 1. The door 110 may also be opened by use of the hinges 103. The door 110 may be opened outwards, away from the inner drum (not shown). When the door 110 is in an open state, a user is allowed to access the inner drum where laundry can be placed for drying. Further, the user may remove the laundry from the inner drum via the opened door when the tumble dryer 100 has finished drying the laundry.

[0037] With reference to figure 2, a cross-section through a tumble dryer 100 according to an embodiment of the present disclosure is shown. The tumble dryer 100 may be a heat pump tumble dryer 100, comprising a heat pump arrangement (not shown). The heat pump may be arranged in a space 121 behind the inner 200 and outer 300 drums. In a heat pump tumble dryer, process air drying the laundry may circulate mostly in a closed loop within the housing 120 of the tumble dryer 100, although some exchange of air with the outside may take place. As mentioned, wet laundry is placed in the inner drum (not shown) of the tumble dryer 100, and while the inner drum rotates, a flow of process air is fed through the inner drum to dry the laundry. The flow of process air is produced by a blower or a fan, which may be located in a space 122 below the inner 200 and outer 300 drums, for example. The heat pump may comprise an evaporator, a compressor, a condenser and an expansion valve (not shown). A refrigerant medium is forced through the heat pump arrangement by the compressor, and gathers energy in the evaporator which is released in the condenser, as is well known per se. As is illustrated in fig. 2, a flow of process air 240 is achieved through the inner drum 200 where hot, humid air is extracted from the inner drum 200 by means of the fan arrangement (not shown). The flow of process air 240 leaves the inner drum 200 through the at least one opening 230 and may pass a filter arrangement before reaching the fan arrangement, located in the space 122 below the inner drum 200. The flow of process air 240 may thus flow through the filter arrangement before it reaches the fan arrangement and then arrives at the evaporator (not shown). The evaporator cools the flow of process air such that moisture therein condenses into liquid water. This water may be collected in the bottom section 123 of the tumble dryer 100, and may be drained therefrom through a tube (not shown). A compressor may be provided to obtain the heat pump flow. The flow of process air 240, which is now cooler and contains less water, is passed to the space 121 in the rear side of the tumble dryer 100 and subsequently passes the condenser, which heats the flow of process air 240 again. Then, the heated, dry flow of process air 240 is reintroduced into the inner drum 200 through the at least one opening (not shown) in the second end 202 thereof.

[0038] With continued reference to fig. 2, an outer drum 300 and an inner drum 200 is arranged in the tumble dryer 100. The outer drum 300 has a cylindrical body with a first end 301 and a second end 302, and extends along an axis A. The first end 301 is arranged in the front side 101 of the tumble dryer 100, and the second end 302 is arranged in the rear side 102 of the tumble dryer 100. The outer drum 300 is arranged around and encloses an inner drum 200. The inner drum 200 has a cylindrical body with a first end 201 and a second end 202, and extends along an axis A. The inner drum 200 is rotatable around axis A, and rotates during a drying cycle in order to dry laundry placed therein. The outer drum 300 is fixed relative the inner drum 200. The first end 201 is arranged in the front side 101 of the tumble dryer 100, and is an open end. Thus, the inner drum 200 is hollow. The first end 201 of the inner drum 200 coincides with the door 110, such that the door 110 in an open state allows access into the inner drum 200. Further, the second end 202 of the inner drum 200 is a closed end. The housing 120 has a length that exceeds the length of the inner drum 200, such that a space 121 is formed on the rear side of the tumble dryer 102, behind the second end 202 of the inner drum 200. The space 121 may be functioning as an enclosure for an air duct (not shown), a heat pump unit (not shown), a fan arrangement (not shown), or a driving means for the fan arrangement or the inner drum 200, for example. There is further a space 122 in the housing 120 beneath the inner drum 200. The space 122 may function as an enclosure for an air duct (not shown), a heat pump unit (not shown), a fan arrangement (not shown), or a driving means for the fan arrangement or the inner drum 200, for example. In the space above the outer drum 300, there is a driving means 400 arranged for driving the rotation of the inner drum 200. The driving means is a motor 400, coupled with a belt 401. The belt 401 is arranged around the inner drum 200, through an opening (not shown) in the top side of the outer drum 300. The motor 400 may be attached to a partition wall 402 arranged in the second end 302 of the outer drum 300. The partition wall 402 is attached to the bottom side of the housing 120 on one side, and to the top side of the housing 120 on the other side, thereby forming a partition between the outer drum 300, the inner drum 200 and the space 121. The at least one opening 230 arranged around the periphery of the inner drum 200 are a plurality of openings 230. The openings 230 are arranged in a rectangular shape around the periphery of the inner drum 230, and extends a length L along the cylindrical body of the inner drum 200. The air exiting the inner drum 200 may thus end up in the space 122 beneath the inner drum 122. Therefore, the fan arrangement (not shown) may be placed here, generating the flow of process air 240 and recirculating the air from the inner drum 200 back into the inner drum 200 again, via a heat pump unit (not shown).

[0039] With reference to figure 3, a front view of a tumble dryer 100 according to an exemplifying embodiment of the present disclosure is shown. Fig. 3 is shown as a cross-section where the front side 101 of the tumble dryer 100 has been removed. The motor 400 is shown attached to the partition wall 402. The motor 400 is arranged in the center of the width W of the tumble dryer 100. Furthermore, the motor 400 is aligned in the width direction of the tumble dryer 100, with the center C of the inner drum 200 and/or outer drum 300. The belt 401 is arranged around the periphery of the inner drum 200.

[0040] With reference to figure 4a, a cross-sectional view of an inner drum 200 and an outer drum 300 according to exemplifying embodiments of the present disclosure is shown. The outer drum 300 encloses the inner drum 200. The outer drum has a cylindrical body with a first end 301 and a second end 302, wherein the first end 301 is arranged in the front side 101 of the tumble dryer 100. The second end 302 of the outer drum 300 is arranged in the rear side 102 of the tumble dryer 100. The first end 301 of the outer drum 300 is an open end, meaning that the outer drum 300 is hollow, and where the inner drum 200 fits into the hollow space inside the outer drum. The door 110 is arranged in the front side 101 of the tumble dryer 100. The front side 101 of the tumble dryer 100 also has an open end, at least partly coinciding with the open end of the first end 301 of the outer drum 300. The door 110 therefore allows access into the inner drum 200 via the outer drum 300 and the front side 101 of the tumble dryer, when the door 110 is in an open state. The open end of the inner drum 200 may have the same size as the open end of the outer drum 300. The open end of the inner drum 200 may further have the same size as the open end of the front side 101 of the tumble dryer 100. The door 110 is sealed via the first sealing means 310. The first sealing means 310 are arranged on a surface 111 of the door 110 facing the front side 101 of the tumble dryer 100. The first sealing means 310 are arranged around the periphery of the door 110 on the surface 111. Alternatively, the first sealing means 310 are arranged on the front side 101 of the tumble dryer 100, on a surface thereof facing the surface 111 of the door 110. The first sealing means 310 are arranged around the open end of the front side 101 of the tumble dryer 100.

[0041] Further, the space between the inner drum 200 and the outer drum 300 is sealed via second sealing means 210. The second sealing means 210 are arranged on a first end 201 of the inner drum 200 and a first end 301 of the outer drum 300, and on a second end 202 of the inner drum 200 and a second end 302 of the outer drum 300. The second sealing means 210 is arranged in the space between the inner drum 200 and the outer drum 300. The second sealing means 210 are arranged around a periphery of the first end 201 and around a periphery of the second end 202 of the inner drum 200. The second sealing means 210 are arranged on a surface 211 of the first end 201 or the second end 202 of the inner drum 200, both surfaces facing the outer drum 300. Alternatively, the second sealing means 210 are arranged on a surface 311 of the outer drum 300, facing the inner drum 200. The openings 230 in the periphery of the inner drum 200 are shown here arranged in the cylindrical body of the inner drum 200 towards the first end 201 of the inner drum 200. Furthermore, the outer drum 300 comprises an opening 320 arranged in the bottom 303 of the outer drum 300. The opening 320 coincides with the plurality of openings 230 in the inner drum 200.

[0042] Further, there is shown at least one opening 220 in the second end 202 of the inner drum 200. The at least one opening 220 is a plurality of openings 220 distributed over the surface of the second end 202 of the inner drum 200. The outer drum 300 has an opening 330 arranged in the second end 302 thereof. The opening 330 coincides with at least some of the plurality of openings 220 in the inner drum 200. The opening 330 may be connected to the space 121 in the housing 120 of the tumble dryer 100 as was shown in figure 2. The flow of process air 240 entering the inner drum 200 flows in a semi-axial path through the inner drum 200. The flow of process air 240 flows into the inner drum 200 through the opening 330 in the second end 302 of the outer drum 300 and the plurality of openings 220 in the second end 202 of the inner drum 200. The flow of process air 240 then flows out from the inner drum 200 through the plurality of openings 230 in the periphery of the inner drum 200, and the opening 320 in the bottom 303 of the outer drum 300. The second end 302 of the outer drum 300 is perpendicular to the bottom 303 of the outer drum 300.

[0043] Even further, there is a driving means 400 arranged above the inner drum 200 and the outer drum 300. The driving means 400 is a motor connected to the inner drum 200 such that the rotation of the inner drum 200 can be driven by the motor 400. More specifically, the motor 400 is connected via belt gear 401 around the inner drum 200. The motor 400 is arranged on top of the outer drum 300. The belt gear 401 is arranged around the periphery of the inner drum 200 via an opening in the outer drum 300.

[0044] With reference to figure 4b, a cross-sectional view of an inner drum 200 and an outer drum 300 according to exemplifying embodiments of the present disclosure is shown. The second sealing means 210 in figure 4b are a labyrinth seal 210. The labyrinth seal is arranged on the first ends 201, 301 and the second ends 202, 302 of the inner drum 200 and the outer drum 300. Parts of the labyrinth seal 210 is arranged on the surface 211 of the inner drum 200, and the remaining parts of the labyrinth seal 210 is arranged on the surface 311 of the outer drum 300, wherein the surfaces 211 and 311 are facing each other. As can be seen from figure 4b, the parts of the labyrinth seals arranged on the respective surfaces 211, 311 are not abutting each other. This may lead to the labyrinth seal 210 being frictionless. If air should be able to escape the labyrinth seal 210 it needs to escape through the path formed by the space between the labyrinth seal 210 on the respective surfaces 211, 311. As seen in figure 4b, the labyrinth seal 210 has a teeth-like shape.

[0045] With reference to figure 5, a perspective view of an inner drum 200 according to an exemplifying embodiment of the present disclosure is shown. The inner drum 200 is shown from the first end 201, corresponding to the front side 101 of the tumble dryer 100. Here, the surface 211 of the inner drum 200 is shown as a ring section forming an opening in the inner drum 200. Inside the inner drum 200, the plurality of openings 220 can be seen. The plurality of openings 220 are arranged on the surface of the second end 202 of the inner drum 200. Further, the plurality of openings 230 arranged around the periphery of the inner drum 200 are shown. The plurality of openings 230 arranged in the periphery of the inner drum 200 are divided into sections, each section shaped as a rectangle.

[0046] With reference to figure 6, a front view of an inner drum 200 according to an exemplifying embodiment of the present disclosure is shown. The inner drum 200 is shown from a first end 201 thereof, corresponding to a front side 101 of the tumble dryer 100. The plurality of openings 220 in the second end 202 of the inner drum 200 are distributed over the surface of the second end 202. Furthermore, a radial direction R is shown, a direction in which the flow of process air flows out from the first end 201 of the inner drum 200.

[0047] Although features and elements are described above in particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements.

[0048] Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the figures, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage.

Claims

1. A tumble dryer (100) having a front (101) and a rear side (102), the tumble 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 (201) and a second end (202), wherein the first end (201) is arranged in the front side (101) of the tumble dryer (100);

a fixed outer drum (300) coaxially arranged 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 in the front side (101) of the tumble dryer (100);

a door (110) arranged in the front side (101) of the tumble dryer (100), and configured to allow access to the inner drum (200);

a first sealing means (310) configured to seal a space between the front side (101) of the tumble dryer (100) and the door (110), wherein the first sealing means (310) is arranged on a surface (111) of the door (110) facing the front side (101) of the tumble dryer (100) or on the front side (101) of the tumble dryer (100) facing the surface (111) of the door (110);

a second sealing means (210) configured to seal a space between the inner drum (200) and the outer drum (300), the second sealing means (210) arranged on at least one surface (211) of the inner drum (200) facing the outer drum (300) alternatively on at least one surface (311) of the outer drum (300) facing the inner drum (300);

a fan arrangement arranged to generate a flow of process air (240) through the inner drum (200); wherein

the flow of process air (240) enters the inner drum (200) through at least one opening (220) in the second end (202) of the inner drum (200), and exits the inner drum (200) in a radial direction (R) through at least one opening (230) in the periphery of the inner drum (200).

2. Tumble dryer (100) according to claim 1, wherein the outer drum (300) comprises at least one opening (320) on a bottom side (303) thereof, the bottom side (303) being perpendicular to the first end (301).

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

4. Tumble dryer (100) according to any preceding claim, wherein the outer drum (300) further comprises at least one opening (330) arranged in the second end (302) thereof, the at least one opening (330) is arranged to align with the at least one opening (220) in the second end (202) of the inner drum (200).

5. Tumble dryer (100) according to any preceding claim, wherein the at least one opening (220) in the second end (202) of the inner drum (200) is a plurality of openings.

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

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

8. Tumble dryer (100) according to any preceding claim, wherein the first sealing means (310) is a gasket.

9. Tumble dryer (100) according to any preceding claim, wherein the second sealing means (210) is arranged on the first (201) and second ends (202) of the inner drum (200) on a surface (211) facing the outer drum (300) alternatively on the first (301) and second (302) ends of the outer drum (300), on a surface (311) facing the inner drum (300).

10. Tumble dryer (100) according to any preceding claim, wherein the second sealing means (210) is a gasket continuously arranged around the periphery of the inner drum (200) on a surface facing the outer drum (300).

11. Tumble dryer (100) according to any preceding claim, wherein the second sealing means (210) is a labyrinth seal comprising two mating gaskets, wherein the first gasket is arranged on the inner drum (200), and the second gasket is arranged on the outer drum (300).

12. Tumble dryer (100) according to any preceding claim, further comprising a driving means (400) for driving the rotation of the inner drum (200).

13. Tumble dryer (100) according to claim 12, wherein the driving means (400) is a motor.

14. Tumble dryer (100) according to claims 12 or 13, wherein the driving means is arranged on a top side of the outer drum (300).

15. Tumble dryer (100) according to any preceding claim, wherein the outer drum (300) has a circular cross section.

Drawing