Drying Air Return Duct For A Laundry Appliance

Description

FIELD

The present disclosure relates to a laundry appliance, and more specifically to a drying air return duct for a dryer.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

Laundry appliances have become a nearly ubiquitous feature of residential spaces and have many additional commercial applications. The laundry appliances include washers, dryers, and washer/dryer combination machines, the latter of which perform both washing and drying functions.

In both washer/dryer combination machines and appliances that exclusively perform drying functions, the appliance generally includes a cabinet or housing with an internal cavity that is accessible via an appliance door. Generally, a drum is positioned within the cabinet such that it is rotatable with respect to the cabinet. Within the drum, there typically exists a laundry compartment, which is accessible using the appliance door, wherein clothes for washing and/or drying are placed during their respective wash and/or dry cycles.

There are several varieties of dryers, which include heat pump dryers and ventless dryers. Regardless of the heat source, each appliance is generally equipped with a drying air recirculation system that provides drying air to the laundry compartment for the purpose of removing water from the laundry within the compartment. There remains room for improved drying air recirculation systems that would decrease drying time and increase energy consumption efficiency.

SUMMARY

This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.

In accordance with one aspect of the present disclosure, a laundry appliance is provided that comprises a cabinet, a drum, a drying air recirculation system, and a drying air return duct. The drum is positioned within the cabinet and the drum defines a laundry compartment therein. The drum is rotatably supported within the cabinet and is rotatable about an axis of rotation. The drying air return duct is arranged in fluid communication with the drying air recirculation system and has a first duct portion that runs between the drum and a rear wall of the cabinet, a second duct portion that bends away from the drum and towards the rear wall of the cabinet, and a third duct portion that extends back towards the drum. The drying air return duct has a geometry that is configured to supply drying air into the laundry compartment at a discharge angle that is substantially parallel to the axis of rotation.

In accordance with another aspect of the present disclosure, the drying air return duct extends from a duct inlet that is arranged in communication with a drying air outlet of the drying air recirculation system to a duct outlet that is arranged in fluid communication with the laundry compartment.

In accordance with another aspect of the present disclosure, the drying air return duct includes a front duct wall and a rear duct wall. In the first duct portion, the front duct wall and the rear duct wall run substantially parallel to the rear cabinet wall. In the second duct portion, the front duct wall and the rear duct wall extend away from the drum at a first angle.

In accordance with another aspect of the present disclosure, the front duct wall and the rear duct wall extend at a second angle back towards the drum in the second duct portion.

In accordance with another aspect of the present disclosure, the first duct portion is adjacent to the duct inlet and has a first cross-sectional area. The second duct portion is downstream of the first duct portion and has a variable cross-sectional area which increases in size moving downstream.

In accordance with another aspect of the present disclosure, the third duct portion is downstream of the second duct portion, and the third duct portion has a third cross-sectional area that is larger than the first cross-sectional area of the first duct portion.

In accordance with another aspect of the present disclosure, the drying air return duct includes an outlet portion which extends from the third duct portion to the duct outlet. The duct outlet is located at a position that is directly adjacent to a central region of the laundry compartment.

In accordance with another aspect of the present disclosure, the laundry appliance additionally includes a grille that is positioned within the drying air return duct. The grille is located between the duct outlet and the third duct portion and is therefore spaced rearward of the duct outlet and the drum.

In accordance with another aspect of the present disclosure, the drying air return duct has a substantially vertical centerline and is asymmetrical relative to the substantially vertical centerline when viewed from the rear and viewed from the side.

In accordance with another aspect of the present disclosure, the drying air recirculation system further includes a blower fan, an evaporator, and a condenser.

In accordance with another aspect of the present disclosure, the drying air recirculation system further includes a blower fan and a heater.

In accordance with another aspect of the present disclosure, a laundry appliance is provided that comprises a cabinet, a drum, a drying air recirculation system, and a drying air return duct. The cabinet includes a front cabinet wall and a rear cabinet wall. The drum is positioned within the cabinet and defines a laundry compartment within the drum. The drum includes an open front end adjacent to the front cabinet wall and an open rear end which abuts a rear bulkhead. The rear bulkhead is positioned between the drum and the rear cabinet wall. The drying air recirculation system includes a drying air inlet, a drying air outlet, and a blower fan. The drying air return duct is positioned in the cabinet between the rear bulkhead and the rear cabinet wall and is arranged in fluid communication with the drying air recirculation system. The drying air return duct includes a first duct portion, a second duct portion downstream of the first duct portion, and a third duct portion downstream of the second duct portion. The first duct portion runs substantially parallel to the rear bulkhead. The second duct portion extends away from the rear bulkhead at a first angle that is oblique relative to the rear bulkhead. The third duct portion extends back towards the rear bulkhead at a second angle that is oblique relative to the rear bulkhead.

In accordance with another aspect of the present disclosure, the drying air return duct includes a front duct wall, a rear duct wall, and two side duct walls. The front duct wall and the rear duct wall run substantially parallel to the rear bulkhead in the first duct portion.

In accordance with another aspect of the present disclosure, the first duct portion has a first cross-sectional area. The first duct portion is adjacent to a duct inlet that is arranged in fluid communication with the drying air outlet of the drying air recirculation system.

In accordance with another aspect of the present disclosure, the two side duct walls flare outwards and away from each other in the second duct portion, which gives the second duct portion a variable cross-sectional area that increases in size moving downstream.

In accordance with another aspect of the present disclosure, the third duct portion has a third cross-sectional area that is larger than a first cross-sectional area of the first duct portion.

In accordance with another aspect of the present disclosure, the third duct portion includes an upper duct wall and a rear duct wall. The upper duct wall extends forward from the rear duct wall in a direction that is substantially parallel to an axis of rotation of the drum.

In accordance with another aspect of the present disclosure, the drying air return duct includes an outlet portion which extends from the third duct portion to the rear bulkhead. The duct outlet is located at a position that is directly adjacent to a central region of the laundry compartment.

In accordance with another aspect of the present disclosure, the laundry appliance additionally includes a grille which is positioned within the drying air return duct between the outlet portion and the third duct portion at an angle that is oblique relative to the upper duct wall.

In accordance with another aspect of the present disclosure, a laundry appliance is provided that includes a cabinet, a drum, a basement region, and a drying air return duct. The cabinet includes a front cabinet wall, a rear cabinet wall, a top cabinet wall, a bottom cabinet wall, and two side cabinet walls. The drum is positioned within the cabinet and includes a cylindrical side wall which defines a laundry compartment within the drum. The drum has an open front end which is adjacent to the front cabinet wall, and an open rear end that abuts a rear bulkhead which is positioned in the cabinet adjacent to the rear cabinet wall. The drum is rotatably supported within the cabinet and is rotatable about an axis of rotation that extends through a central region of the laundry compartment. The basement region is positioned in the cabinet below the drum and above the cabinet wall. The basement region is defined by one or more basement walls and houses a drying air recirculation system, which includes a drying air inlet, a drying air outlet, one or more heat exchangers, and a blower fan. The heat exchanger(s) and the blower fan are arranged along a drying air recirculation path, which extends from the drying air inlet to the drying air outlet. The drying air return duct is positioned in the cabinet between the rear bulkhead and the rear cabinet wall. The drying air return duct extends from a duct inlet that is arranged in fluid communication with the drying air outlet of the drying air recirculation system to a duct outlet that is arranged in fluid communication with the laundry compartment of the drum. The drying air return duct includes a front duct wall and a rear duct wall. The drying air return duct additionally includes a first duct portion located adjacent to the duct inlet that is arranged in fluid communication with the drying air outlet of the drying air recirculation system. In the first duct portion, the front duct wall and the rear duct wall are substantially parallel to the rear bulkhead. The drying air return duct additionally includes a second duct portion downstream of the first duct portion. In the second duct portion, the front duct wall and the rear duct wall extend away from the rear bulkhead at a first angle. The drying air return duct additionally includes a third duct portion downstream of the second duct portion. In the third duct portion, the front duct wall and the rear duct wall extend back towards the rear bulkhead at a second angle. The drying air return duct additionally includes an outlet portion which extends from the third duct portion to the rear bulkhead. The duct outlet is located at a position that is directly adjacent to the central region of the laundry compartment such that drying air is directed into the central region of the laundry compartment.

Advantageously, the location of the duct outlet in cooperation with the geometry of the various duct sections of the drying air return duct permits drying air to enter into the laundry compartment at a discharge angle that is substantially parallel to the axis of rotation of the drum, thereby increasing efficiency of the laundry appliance by reducing drying time and decreasing the development of hot spots within the drum.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations and are not intended to limit the scope of the present disclosure.

FIG. 1 is a front perspective view of a laundry appliance constructed in accordance with the present disclosure;

FIG. 2 is a rear perspective view of the exemplary laundry appliance shown in FIG. 1 where cabinet walls of the laundry appliance are illustrated in dashed lines and internal components of the laundry appliance including a drum, drying air return duct, and basement walls are illustrated in solid lines;

FIG. 3 is a rear perspective view of the drum and drying air return duct, which have been constructed in accordance with the present disclosure;

FIG. 4 is a side elevation view of the drum and drying air return duct shown in FIG. 3;

FIG. 5 is a front perspective view of an upper portion of the drying air return duct shown in FIG. 3;

FIG. 6 is a side elevation view of the upper portion of the drying air return duct shown in FIG. 5;

FIG. 7 is a front elevation view of the drying air return duct shown in FIG. 5;

FIG. 8 is a graphical representation of a drying air discharge angle of a prior art drying air return duct into the drum of a conventional dryer; and

FIG. 9 is a graphical representation of a drying air discharge angle of the drying air return duct into the drum of a laundry appliance that has been constructed in accordance with the present disclosure.

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings.

Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

With reference to FIGS. 1 and 2, a laundry appliance 20 is illustrated. The laundry appliance 20 is a heat-pump dryer or ventless dryer, but alternatively could be a vented dryer or a washer/dryer combination machine.

The laundry appliance 20 includes a cabinet 22 that is rectangular in shape. The cabinet 22 includes a front cabinet wall 24, a rear cabinet wall 26 opposite the front cabinet wall 24, two side cabinet walls 28 that run between and connect the front cabinet wall 24 and the rear cabinet wall 26, a top cabinet wall 30, and a bottom cabinet wall 32 opposite the top cabinet wall 30. Collectively, the top cabinet wall 30, bottom cabinet wall 32, front cabinet wall 24, rear cabinet wall 26 and two side cabinet walls 28 cooperate with one another to form a cavity 34 within the interior of the cabinet 22.

The laundry appliance 20 may be equipped with a control panel 36. The control panel 36 may be positioned along the front cabinet wall 24 adjacent to the top cabinet wall 30, or in any suitable location on the laundry appliance 20. The control panel 36 may include a display 38, a speaker 40, a control knob 42, and a control module 44. The display 38 may be utilized to display information regarding the status of laundry within the laundry appliance 20, adjust settings of the laundry appliance 20, present prompts regarding settings or other information to a user of the laundry appliance 20, and to perform any other associated functions. The display 38 may include a touch screen portion configured to receive an input from a user. The speaker 40 may be used to output audible sounds to a user such as notifying a user of a status of the laundry load, or any other suitable function. The control knob 42 may be utilized by the user to input a selection or to adjust a setting of the laundry appliance 20. The control knob 42 may additionally perform one or more other functions. The control module 44 may receive an input from a user via the display 38 or the control knob 42, and may be configured to operate a given selection such as a drying cycle of the laundry appliance 20, as well as one or more additional functions.

As shown in FIG. 1, the laundry appliance 20 has a front-load configuration and includes a door 46, which is pivotally attached to the front cabinet wall 24. The door 46 is configured to swing between a closed position and an open position. In the open position, the door 46 is further configured to provide access to the cavity 34, and more specifically to a drum 48 within the cavity 34 of the cabinet 22. In the closed position, the door 46 prevents access to the drum 48. When in the closed position, the door 46 may be flush with or positioned adjacent to the front cabinet wall 24.

The drum 48 is positioned within the cavity 34 of the cabinet 22 and is rotatably supported with respect to the cabinet 22 about an axis of rotation 52, which extends through a central region CR of the drum 48. The drum 48 has a cylindrical drum side wall 54, which extends from a front drum end 56 to a rear drum end 58. The front drum end 56 includes a front drum opening 60 located adjacent to the door 46 and a rear drum opening 62 that abuts a rear bulkhead 64. The rear bulkhead 64 is positioned in the cabinet 22 adjacent to the rear cabinet wall 24 and is stationary inside the cabinet 22 (i.e., the rear bulkhead 64 does not rotate with the drum 48).

The front drum end 56, the cylindrical drum side wall 54, and the rear bulkhead 64 cooperate to define a laundry compartment 66 within the drum 48. The front drum opening 60 is aligned with the door 46 such that the door 46 provides access to the drum 48 and thereby the laundry compartment 66 when the door 46 is in the open position. As shown in FIG. 9, the axis of rotation 52 of the drum 48 extends through the central region CR of the drum 48. It should be appreciated by one skilled in the art that the laundry compartment 66 receives and therefore contains laundry (e.g., clothes, towels, and/or bedding, etc.) during a drying cycle of the laundry appliance 20.

As shown in FIG. 2, the laundry appliance 20 additionally includes a basement region 68, which is positioned in the cabinet 22 below the drum 48 and above the bottom cabinet wall 32. The basement region 68 is defined by a front basement wall 70 that is adjacent to or flush with the front cabinet wall 24, a rear basement wall 72 that is adjacent to or flush with the rear cabinet wall 26, two basement side walls 74 that are adjacent to or flush with the side cabinet walls 28, and a top basement wall 75 that is positioned below the drum 48 and above the bottom cabinet wall 32. The basement region 68 houses a drying air recirculation system 76 which includes a drying air inlet 78, a drying air outlet 80, one or more heat exchangers 82, and a blower fan 84, which are all arranged along a drying air recirculation path extending from the drying air inlet 78 to the drying air outlet 80. The heat exchanger(s) 82 are configured to remove moisture from air flowing through the drying air recirculation system 76 and may include a condenser and an evaporator when the laundry appliance 20 is a heat-pump dryer. If the laundry appliance 20 is a vented dryer, the heat exchanger(s) 82 may be replaced by a heater, such as an electric heater or natural-gas heater.

The drying air outlet 80 of the drying air recirculation system 76 is arranged in fluid communication with a drying air return duct 86, which is positioned within the cabinet 22 between the rear bulkhead 64 and the rear cabinet wall 26. The drying air return duct 86 extends from a duct inlet 88 to a duct outlet 90 and transports drying air from the drying air recirculation system 76 to the laundry compartment 66 during a drying cycle. The duct inlet 88 is coupled to the drying air outlet 80 of the drying air recirculation system 76, and the duct outlet 90 is along the rear bulkhead 64.

With reference to FIGS. 3-7, the drying air return duct 86 generally includes a front duct wall 92, a rear duct wall 94, a first duct side wall 96, and a second duct side wall 98. The drying air return duct 86 may be further separated into three representative portions including a first duct portion 100, a second duct portion 102, and a third duct portion 104. The first duct portion 100 of the drying air return duct 86 is adjacent to and transitions out of the duct inlet 88, which is coupled to and receives drying air from the drying air outlet 80. In the first duct portion 100, the front duct wall 92 and the rear duct wall 94 run substantially parallel to one another, as do the first duct side wall 96 and the second duct side wall 98. This directionality of the walls 92, 94, 96, 98 in the first duct portion 100 creates a first cross-sectional area 106 that is substantially the same throughout the first duct portion 100 of the drying air return duct 86 moving downstream. In addition to running substantially parallel to one another, the front duct wall 92 and the rear duct wall 94 also run substantially parallel to the rear bulkhead 64 and the rear cabinet wall 26 in the first duct portion 100.

The second duct portion 102 of the drying air return duct 86 is located adjacent to and downstream of the first duct portion 100, and bends away from the drum 48 at a first oblique angle A1, with both the front duct wall 92 and the rear duct wall 94 running substantially in parallel with one another along the first oblique angle A1, giving the drying air return duct 86 an asymmetrical shape when viewed from the side (as shown in FIG. 4). The first oblique angle A1 is an obtuse angle of more than 90 degrees and less than 180 degrees. For example, and without limitation, the first oblique angle A1 may fall within the range of 150 degrees to 170 degrees and may more preferably be substantially equal to 160 degrees. As the second duct portion 102 progresses downstream towards the third duct portion 104, the first duct side wall 96 and the second duct side wall 98 flare laterally away from one another relative to a substantially vertical centerline 108 of the drying air return duct 86, with the first duct side wall 96 extending away from the centerline 108 at a more acute angle than the second duct side wall 98, thereby creating an asymmetrical shape when viewed from the front (as shown in FIG. 7) and a variable second cross-sectional area 110, which increases in size moving downstream towards the third duct portion 104 of the drying air return duct 86. Thus, in addition to the creation of a variable second cross-sectional area 110, the lateral flare of the first duct side wall 96 and the second duct side wall 98 causes the drying air return duct to appear asymmetrically relative to the vertical centerline 108 when viewed from the front, rear, and from the side.

The third duct portion 104 is located adjacent to and downstream of the second duct portion 102. The third duct portion 104 bends back towards the drum 48 at a second oblique angle A2, with the front duct wall 92 and the rear duct wall 94 extending in parallel towards the rear bulkhead 64 until the rear duct wall 94 reaches an upper duct wall 112, which extends forward from the rear duct wall 94 in a direction that is substantially parallel to the axis of rotation 52 of the drum 48. The second oblique angle A2 is an acute angle of more than 0 degrees and less than 90 degrees. For example, and without limitation, the second oblique angle A2 may fall within the range of 66 degrees to 70 degrees.

The third duct portion 104 has a third cross-sectional area 114, which is generally consistent throughout the third duct portion 104 and is larger than the first cross-sectional area 106 of the first duct portion 100.

With continuing reference to FIGS. 3-7, the drying air return duct 86 terminates in an outlet portion 116, which extends from the third duct portion 104 to the rear bulkhead 64 in a direction that is substantially parallel to the axis of rotation 52 of the drum 48. The outlet portion 116 is preferably an ovoid rectangle in cross-sectional shape, having a substantially planar top outlet edge 118 terminating in two outlet corners 120 and transitioning into a rounded rectangular outlet bottom edge 122, but may be any suitable shape for delivering drying air into the laundry compartment 66 at a discharge angle DA that is substantially parallel to the axis of rotation 52 of the drum 48 (i.e., the discharge angle DA is less than or equal to plus or minus five degrees relative to the axis of rotation 52 of the drum 48). The drying air return duct 86 includes a grille 124 that is positioned between the outlet portion 116 and the third duct portion 104 such that the grille 124 is located rearward of the rear bulkhead 64.

FIG. 8 is a graphical representation of an illustrative infrared airflow analysis, which illustrates the entry of drying air into the laundry compartment 166 of the drum 148 of a conventional dryer. The drum 148 has a cylindrical drum side wall 154 that extends longitudinally from a front drum end 156 to a rear drum end 158. A conventional drying air return duct 186 runs parallel with the rear drum end 158 to a duct outlet 190 that is positioned near the upper rear corner of the drum 148 where the drum side wall 154 meets the rear drum end 158. As a result of this geometry, drying air exits the duct outlet 190 at a substantial discharge angle DA of 25 degrees or more relative to the axis of rotation 152 of the drum 148. As illustrated in FIG. 8, the location of the duct outlet 190 and the discharge angle DA in conventional dryers focuses the drying air into the upper rear corner of the drum 148 where the drum side wall 154 meets the rear drum end 158, but that is not ideal for drying efficiency and results in the creation of hot spots within the drum 148 and laundry compartment 166.

FIG. 9 is a graphical representation of an illustrative infrared airflow analysis, which illustrates the entry of drying air into the laundry compartment 66 of the laundry appliance 20 described herein. The location of the duct outlet 90 and the geometry of the drying air return duct 86 allows drying air to enter the drum 48 at a discharge angle DA that is substantially parallel to the axis of rotation 52 of the drum 48 (i.e., the discharge angle DA is less than or equal to plus or minus five degrees relative to the axis of rotation 52 of the drum 48) and pass into the central region CR of the laundry compartment 66, which is spaced inward of the drum side wall 54, the front drum end 56, and the rear drum end 58. The location of the duct outlet 90 in cooperation with the geometry of the drying air return duct 86 therefore focuses the drying air entering the drum 48 towards the central region CR of the laundry compartment 66 where the laundry is tumbling, thereby increasing efficiency of the laundry appliance 20, reducing drying time, and decreasing the development of hot spots within the drum 48.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.