LAUNDRY DRYER

Abstract

A laundry dryer including: a drum, a motor to rotate the drum, a casing supporting the drum and including a rear wall and a front wall, a basement having first, second, third and fourth quarters with the first and third quarters on one side of a plane perpendicular to the basement plane and parallel to the drum axis, and the second and fourth quarters on an opposite side of the plane, a process air conduit in fluid communication with the drum and including a basement process air conduit located in the basement, and a heat pump circuit including a compressor, and first and second heat exchangers . The first and second heat exchangers are in the basement process air conduit mainly within third and fourth quarters, and the motor and compressor are mainly in, respectively, in the first and second quarters.

Claims

1. A laundry dryer comprising: a drum configured to contain laundry to be dried, said drum being rotatable about a drum axis (R); a motor configured to rotate the drum about the drum axis (R): a casing rotatably supporting the drum and including: a rear wall and a front wall; a basement defining a basement plane and in which a first quarter, a second quarter, a third quarter and a fourth quarter are defined by two intersecting first and second planes, the first plane being perpendicular to said basement plane and passing through said drum axis and the second plane being perpendicular to said first plane and passing through a center line of the basement substantially parallel to said rear wall of the casing, the first quarter and the third quarter being defined on one side of the first plane and the second quarter and said fourth quarter being defined on an opposite side of the first plane; a process air conduit in fluid communication with the drum and configured to convey a flow of process air, said process air conduit including a basement process air conduit located in the basement; a heat pump having a heat pump circuit configured to convey a flow of a refrigerant, said heat pump circuit including a compressor, a first heat exchanger where the refrigerant is cooled off and the process air is heated up, and a second heat exchanger where the refrigerant is heated up and the process air is cooled off; said first heat exchanger and said second heat exchanger being arranged in the basement process air conduit within said third quarter and said fourth quarter of said basement for a majority of each of their respective volumes in order to perform heat exchange between said refrigerant flowing in said heat pump circuit and said process air; and wherein said motor and said compressor are located, respectively, in said first quarter and said second quarter (Q1, Q2) of said basement for a majority of each of their respective volumes.

2. The laundry dryer according to claim 1, wherein said basement process air conduit formed in said basement includes a first duct wall located within said first quarter of said basement and a second duct wall located within said second quarter of said basement, said first duct wall and said second duct wall converging to a basement process air outlet.

3. The laundry dryer according to claim 2, wherein in a section along a sectioning plane parallel to said basement plane, said first duct wall and said second duct wall respectively define a first converging curve and a second converging curve.

4. The laundry dryer according to claim 3, wherein said first fist converging curve and said second converging curve are axially symmetric with respect to a duct axis parallel to said drum axis.

5. The laundry dryer according to claim 4, wherein the duct axis of said basement process air circuit lies on the first plane.

6. The laundry dryer according to claim 1, further comprising a fan located in proximity of a basement process air outlet of said basement downstream of said first heat exchanger and said second heat exchanger in a direction of flow of said process air, said fan being configured to rotate around a fan axis, wherein said fan axis is positioned higher than a symmetry axis, parallel to the fan axis, of said first heat exchanger or said second heat exchanger.

7. The laundry dryer of claim 6, wherein the fan axis is parallel to said basement plane.

8. The laundry dryer according to claim 6, wherein the fan axis lies on the first plane.

9. The laundry dryer according to claim 1, wherein said basement includes an upper shell portion and a lower shell portion connected to said upper shell portion, said basement process air duct being formed between said upper shell portion and said lower shell portion.

10. The laundry dryer according to claim 1, wherein a first portion of said basement process air conduit within said third quarter and said fourth quarter of said basement has a width equal to at least 50% of a width of the basement.

11. The laundry dryer according to claim 1, wherein a second portion of said basement process air conduit within said first quarter and said second quarter of said basement has a width equal to less than 50% of a width of the basement.

12. The laundry dryer according to claim 1, wherein said first quarter and said second quarter of the basement contact said rear wall.

13. The laundry dryer according to claim 2, wherein the motor and the compressor are positioned adjacent to the first duct wall and the second duct wall, respectively.

14. The laundry dryer according to claim 1, wherein said drum includes a first end and a second end, the second end facing the rear wall of the casing and being closed by a back wall attached to the drum.

15. The laundry dryer according to claim 1, wherein the basement includes a basement process air outlet facing the rear wall.

16. The laundry dryer according to claim 1, wherein said casing includes a door and said front wall includes an aperture, said door being hinged on said front wall and configured to open and close said aperture.

17. The laundry dryer according to claim 1, wherein the refrigerant in said heat pump circuit includes propane.

18. The laundry dryer according to claim 1, wherein a projection on rear wall of said first heat exchanger and/or a projection on a rear wall of said second heat exchanger, and a projection on a rear wall of the compressor or on a rear wall of the motor at least partially overlap.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0094] The present invention will now be described with reference to the accompanying drawings that illustrate non-limiting embodiments thereof, wherein:

[0095] FIG. 1 is a schematic view of a heat pump laundry dryer according to the invention;

[0096] FIG. 2 shows a perspective view of the laundry dryer of FIG. 1;

[0097] FIG. 3 is a top view, with parts removed, of the basement of the laundry dryer of FIG. 2;

[0098] FIG. 4 is an additional top view of the basement of FIG. 3 with the upper portion removed;

[0099] FIG. 5 is a rear sectioned view of a portion of the laundry dryer of FIG. 2 along the C-C line of FIG. 4;

[0100] FIG. 6 is a rear sectioned view of a portion of the laundry dryer of FIG. 2 along the B-B line of FIG. 4; and

[0101] FIG. 7 is a rear sectioned view of a portion of the laundry dryer of FIG. 2 along the A-A line of FIG. 4.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0102] With initial reference to FIGS. 1 and 2, a laundry dryer realized according to the present invention is globally indicated with 1.

[0103] Laundry dryer 1 comprises an outer box or casing 2, preferably but not necessarily parallelepiped-shaped, and a drying chamber, such as a drum 3, for example having the shape of a hollow cylinder, for housing the laundry and in general the clothes and garments to be dried. The drum 3 is preferably rotatably fixed to the casing 2, so that it can rotate around a preferably horizontal axis R (in alternative embodiments, rotation axis may be tilted). Access to the drum 3 is achieved for example via a door 4, preferably hinged to cabinet 2, which can open and close an opening 4a realized on the cabinet itself.

[0104] More in detail, casing 2 generally includes a front wall 20, a rear wall 21 and two sidewalls 25, all mounted on a basement 24. Preferably, the basement 24 is realized in plastic material. Preferably, basement 24 is molded via an injection molding process. Preferably, on the front wall 20, the door 4 is hinged so as to access the drum. The casing, with its walls, defines the inner volume of the laundry dryer 1. Similarly, the basement defines the basement inner volume delimited by the basement's walls. Advantageously, basement 24 includes an upper and a lower shell portion 24a, 24b (visible in FIGS. 3 and 5 detailed below). The width of the casing, which is the same as the width of the basement, is indicated with W in the drawing and it is defined either as the width of the front or rear wall (having in this example the same width) or by the distance between the two lateral walls 25.

[0105] The dryer 1, and in particular basement 24, defines an horizontal plane which is substantially the plane of the ground on which the dryer 1 is situated, thus it is considered to be substantially horizontal, and a vertical direction Z perpendicular to the plane . The plane defined by the basement however can be also tilted from the horizontal one.

[0106] Laundry dryer 1 also preferably comprises an electrical motor assembly 50 for rotating, on command, revolving drum 3 along its axis inside cabinet 2. Motor 50 includes a shaft 51, which defines a motor axis of rotation M (see FIGS. 3 and 4).

[0107] Further, laundry dryer 1 may include an electronic central control unit (not shown) which controls both the electrical motor assembly 50 and other components of the dryer 1 to perform, on command, one of the user-selectable drying cycles preferably stored in the same central control unit. The programs as well other parameters of the laundry dryer 1, or alarm and warning functions can be set and/or visualized in a control panel 11, preferably realized in a top portion of the dryer 1, such as above door 4.

[0108] With reference to FIG. 1, the rotatable drum 3 includes a mantle, having preferably a substantially cylindrical, tubular body 3c, which is preferably made of metal material and is arranged inside the cabinet 2 and apt to rotate around the general rotational axis R which can be—as said—horizontal, i.e. parallel to the plane, or tilted with respect to the latter. The mantle 3c defines a first end 3a and a second end 3b and the drum 3 is so arranged that the first end 3a of the mantle 3c is faced to the laundry loading/unloading opening 4a realized on the front wall 20 of the cabinet 2 and the door 4, while the second end 3b faces the rear wall 21.

[0109] Drum 3 may be an open drum, i.e. both ends 3a and 3b are opened, or it may include a back wall (not shown in the appended drawings) fixedly connected to the mantle and rotating with the latter.

[0110] In order to rotate, support elements for the rotation of the drum are provided as well in the laundry of the invention. Such support elements might include rollers at the front and/or at the back of the drum, as well as or alternatively a shaft connected to the rear end of the drum (shaft is not depicted in the appended drawings). For example, rollers connected to the basement 24 via bosses may be used. Any support element for the rotation of the drum around axis R is encompassed by the present invention.

[0111] Dryer 1 additionally includes a process air circuit which comprises the drum 3 and an air process conduit 11, depicted as a plurality of arrows showing the path flow of a process air stream through the dryer 1 (see FIG. 1). In the basement 24, a portion of the air process conduit 11, called basement process air conduit or duct 18, is formed by the connection of the upper shell 24a and the lower shell 24b. Basement process conduit 18 is preferably connected with its opposite ends to the two opposite sides of drum 3, i.e. first and second rear end 3a, 3b of mantle 3c. Process air circuit also includes a fan or blower 12 (shown in FIG. 1).

[0112] A filter 103 may be positioned in the conduit 11 to filter process air coming from the drum 3.

[0113] The dryer 1 of the invention additionally comprises a heat pump system 30 including a first heat exchanger (called also condenser) 31 and a second heat exchanger (called also evaporator) 32 (see FIG. 1). Heat pump 30 also includes a refrigerant closed circuit (partly depicted) in which a refrigerant fluid flows, when the dryer 1 is in operation, cools off and may condense in correspondence of the condenser 31, releasing heat, and warms up, in correspondence of the second heat exchanger (evaporator) 32, absorbing heat. A compressor receives refrigerant in a gaseous state from the evaporator 32 and supplies the condenser 31, thereby closing the refrigerant cycle. In the following, the heat exchangers are named either condenser and evaporator or first and second heat exchanger, respectively. More in detail, the heat pump circuit connects via piping 35 (see FIG. 3) the second heat exchanger (evaporator) 32 via a compressor 33 to the condenser 31. The outlet of condenser 31 is connected to the inlet of the evaporator 32 via an expansion device (not visible), such as a choke, a valve or a capillary tube.

[0114] Each heat exchanger 31, 32 includes a plurality of tubes positioned in parallel, forming different layers. The number of layers defines the thickness of the heat exchanger. The thickness of the condenser is indicated with tc and the thickness of the evaporator with te. Preferably, as shown in FIG. 3, tc >te. The tubes are connected via lateral ducts or pipes 36. Each heat exchanger defines a heat exchanger surface, having a width equal to Whe. The width of the heat exchanger 31, 32 is preferably substantially parallel to the front or rear wall 20, 21 of the casing 3. The length Whe does not include the ducts' 36 extension. The height of the heat exchangers is limited by the presence of the drum above them (better detailed below). Preferably, the width of the condenser is substantially identical to the width of the evaporator.

[0115] Each heat exchanger defines a heat exchange surface, which is the surface which is hit by the process air. The heat exchange surface has preferably a rectangular shape, given by the width and height of the heat exchangers. The heat exchange surface defines a center, for example the point of intersection of the two diagonals of the rectangle, and each heat exchanger defines therefore a heat exchanger axis EX as the line connecting all the heat exchange surfaces' centers. Preferably, the heat exchanger axis EX of the evaporator coincides with the heat exchanger axis EX of the condenser and therefore in the figure a single axis is visible.

[0116] Preferably, in correspondence of evaporator 32, the laundry dryer 1 of the invention may include a condensed-water canister (not visible) which collects the condensed water produced, when the dryer 1 is in operation, inside evaporator 32 by condensation of the surplus moisture in the process air stream arriving from the drum 3. The canister is located at the bottom of the evaporator 32. Preferably, through a connecting pipe and a pump (not shown in the drawings), the collected water is sent in a reservoir located in correspondence of the highest portion of the dryer 1 so as to facilitate a comfortable manual discharge of the water by the user of the dryer 1.

[0117] The condenser 31 and the evaporator 32 of the heat pump 30 are located in correspondence of the process air conduit 18 formed in the basement 24 (see FIGS. 3 and 4).

[0118] In case of a condense-type dryer—as depicted in the appended figures—where the air process circuit is a closed loop circuit, the condenser 31 is located downstream of the evaporator 32. The air exiting the drum 3 enters the conduit 18 and reaches the evaporator 32 which cools down and dehumidifies the process air. The dry cool process air continues to flow through the conduit 18 till it enters the condenser 31, where it is warmed up by the heat pump 30 before re-entering the drum 3.

[0119] It is to be understood that in the dryer 1 of the invention, an air heater, such as an electrical heater, can also be present, in addition to the heat pump 30. In this case, heat pump 30 and heater can also work together to speed up the heating process (and thus reducing the drying cycle time). In the latter case, preferably condenser 31 of heat pump 30 is located upstream the heater. Appropriate measures should be provided to avoid the electric heater to fuse plastic components of the dryer 1.

[0120] Further, with now reference to FIGS. 3 and 4, in the basement, the process air conduit 18 is formed by the upper and the lower shells 24a, 24b and includes an inlet 19in from which process air is received from the drum 3 and an outlet 19out to channel process air out of the basement 24. Between inlet 19in and outlet 19out, the conduit or duct 18 is formed, preferably as two single pieces joined together and belonging to the upper and lower shell 24a, 24b.

[0121] Further, duct 18 includes a first and a second portion 28 and 29. The first portion 28 starts from the inlet 19in of the duct 18, and terminates in the second portion 29, which includes the outlet 19out of the duct. In the first portion 28 of the duct 18, the first and the second heat exchangers 31, 32 are located. Preferably, first and second heat exchanger 31, 32 are placed one after the other, the first heat exchanger 31 being downstream in the direction of flow of the process air the second heat exchanger 32.

[0122] Further, the second portion 29 channels the process air exiting from the first heat exchanger 31 towards the basement outlet 19out. The second portion 29 thus starts at the location of an exit of the first heat exchanger 31, considered as the location of a plane sectioning the duct portion 29 and substantially in contact with a surface of the first heat exchanger 31 from which process air exits.

[0123] Considering now a first plane P1 perpendicular to the basement plane and embedding the rotational axis R of the drum 3, this first plane P1 divides the basement 24 in two halves, called, with now reference to FIGS. 3 and 4, basement first or right half and basement second or left half. These two halves need not to be identical in dimension (i.e. they are not mathematical halves), however in the present depicted embodiment P1 also embeds a first—longitudinal—centerline H1 of the basement. Furthermore, still in the depicted embodiment, P1 is a vertical plane.

[0124] Again with reference to FIGS. 3 and 4, considering now a second plane P2, perpendicular to P1 and to the basement plane and passing through a second centerline H2 of the basement, the basement 24 is divided, by a combination of the first and the second plane P1, P2, in four quarters Q1-Q4. The quarters are numbered in a clockwise manner, the first quarter Q1 being the rearmost quarter of the first half of the basement 24 (e.g. the quarter facing the rear wall 21), the second quarter Q2 being the rearmost quarter of the second half of the basement 24, the third quarter Q3 the foremost quarter (e.g. the quarter facing the front wall 20) of the second half of the basement and the last fourth quarter Q4 the foremost quarter of the first half of the basement 24.

[0125] It can be therefore seen that the heat exchangers 31, 32 and the first duct portion 28 are substantially contained for the majority of their volume within the third and fourth quarter Q3, Q4, the second heat exchanger closer to the front wall 20 than the first heat exchanger 31; preferably compressor 33 is contained for the majority of its volume within the first quarter Q1, while the motor 50 is located for the majority of its volume in the second quarter Q2. The outlet 19out of basement duct 18 is located between the first Q1 and the second quarter Q2, preferably facing rear wall 21 of casing 2. A small portion of the volume of the first heat exchanger is contained in the first and second quarters.

[0126] Motor 50 is preferably contained within the second quarter Q2 and its shaft 51 extends in such a way that it is parallel to plane P1. Preferably, motor shaft 51 is also the shaft of fan 12, which is located in proximity of outlet 19out, preferably facing the latter. Fan 12 blows the process air exiting the basement 24 through outlet 19 into the drum 3, preferably through a passage, not shown, part of the process air circuit 18, formed within the rear wall 21. Preferably, fan 12 includes a propeller 13 which is positioned in the outlet 19out and defines a propeller or fan axis F.

[0127] As visible, the heat exchangers 31, 32 are positioned in front of the basement, that is, close to the front wall 20, while the compressor 33 and the motor 50 are positioned in the rear of the basement, i.e. close to the rear wall 21. However, an opposite configuration, where the heat exchangers are positioned at the rear of the basement and the compressor and motor at the front of the basement is feasible as well.

[0128] The air process duct 18 is divided in two by the first plane P1. Preferably, the air process duct 18 has an axis A and the first plane P1 is including axis A. Preferably, the first plane P1 is also an axis of symmetry of the duct 18, which is divided in two halves by the first plane P1. Alternatively, the first plane P1 still divides the duct in two parts that are not identical.

[0129] On the third and fourth quarters Q3, Q4, the first portion 28 of the duct is positioned, where also the first and the second heat exchanger 31, 32 of heat pump 30 are located. The heat exchangers can be completely contained within the third and fourth quarters or they can also extend beyond the limit defined by the second plane P2, as in the present case. If a portion of the first and/or second heat exchanger 31, 32 is also located within the rear part of the basement 24 (quarters Q1 and Q2), this portion is the minority of the whole volume occupied by the first and/or second heat exchanger 31, 32. The length of the first portion 28 of the duct is therefore at least equal to the distance between the inlet 19in of the duct 18 to the exit of the first heat exchanger 31.

[0130] Duct 18 includes walls which form and delimit the duct itself, and the walls form a closed curve, in other words, when the duct 18 is sectioned on a plane perpendicular to the basement plane , the section of the duct walls defines a closed curve. Walls include a first and a second wall 18w1 and 18w2, considered as lateral wall of the duct. The configuration of walls 18w1 and 18w2 can change also along the extension of the duct, for example close to the outlet 19out, the section of the duct 18 becomes substantially circular and thus lateral walls 18w1 and 18w2 become substantially curvilinear or each of them includes an arch of circumference. In the portion of the duct 28 which contains the heat exchangers 31, 32, each wall has substantially a U shape. Any embodiment of the geometrical configuration of walls 18w1 and 18w2 is encompassed in the present invention.

[0131] Preferably, first and second walls 18w1 and 18w2 are each formed with the upper or lower shell 24a, 24b. That is to say, the upper shell 24a includes part of first wall 18w1 and part of second wall 18w2, while the lower shell 24b includes part of the first wall 18w1 and part of second wall 18w2.

[0132] Considering now a further plane, called sectioning plane PT (several sectioning plane are visible in FIG. 4), a plurality of sections of the basement duct 18 are made as follows. Sectioning plane PT is a plane substantially perpendicular to the basement plane , e.g. it is a vertical plane. Preferably, it is also perpendicular to the first plane P1, e.g. it is parallel to P2.

[0133] Sectioning plane PT thus sections first wall 18w1 and second wall 18w2 generating a first curve and a second curve, respectively. The first and second curves are substantially the curves formed by the edges of the first and second walls—respectively—in the location where they have been sectioned.

[0134] FIG. 5 shows the section of the duct 18 along the plane PT shown in FIG. 4 as sectioning the basement along line C-C. The plane PT in this figure is sectioning the basement parallel to the second plane P2 and in the third and fourth quarters Q3, Q4, corresponding to the first portion 28 of the basement duct 18.

[0135] In this portion, the heat exchangers are located. As shown in FIG. 5, the section of the duct 18 is substantially rectangular. This section is section along line C-C as represented in FIG. 4. The section of the duct 18 is also the widest possible section present in the all extension of the duct. The width of the duct Wd is at least as wide as the width Whe of the heat exchangers 31, 32 in order to contain the same. Preferably, the width Whe of the heat exchangers is at least 50% or more of the width W of the basement itself. Therefore, also the width of the basement duct 18 in the first portion 28 is at least 50% or more of the width W of the basement itself. Preferably, the whole first portion 28 of the duct 18 has this “large” width which preferably remains constant along the extension of the first portion of the duct through the third and fourth quarters Q3, Q4. This first portion of the duct starts with the inlet 19in of the basement duct 18 and terminates with the exit of the condenser 31.

[0136] The exit of the condenser 31 in this embodiment is positioned in the first quarter Q1 close to the second plane P2. Preferably, a plane including the exit of the condenser 31 is parallel to the second plane P2. Further, the exchangers 31, 32 are positioned in the first portion 28 of the duct 18 in such a way that the axis of the heat exchangers EX and the axis A of the duct 18 are parallel and even more preferably they coincide (see FIG. 5).

[0137] After the exit of the condenser 31, the second portion 29 of the duct 18 extends. This second portion starts at the exit of the condenser and terminates at the outlet 19out of the duct 18.

[0138] Two sections of the second portion 29 of the duct 18 along section planes PT positioned in the first and second quarters Q1, Q2 and specifically along lines B-B and A-A of FIG. 4 are shown in FIGS. 6 and 7, respectively. In the second portion 29, the walls of the duct 18w1 and 18w2 are converging, that is, the duct decreases its cross section, and preferably in particular its width, from a maximum which is present at the exit of the first heat exchanger 31, to a minimum present at the outlet 19out.

[0139] The size of the outlet, as shown in FIG. 3, is preferably such as to house the propeller 13 of the fan 12. The second portion 29 of the duct is therefore a substantially monotonously converging portion. Preferably, the decrease in the width Wd of the cross section is monotonous from a maximum Whe to a minimum at the outlet 19out.

[0140] The convergence can be readily seen comparing the width of the duct in FIG. 5 (width of the first portion 28 of the duct), which is reduced in the section of FIG. 6 and which is at the minimum at the outlet as depicted in FIG. 7. The axis A of the second portion 29 of the duct 18 and the axis EX of the heat exchangers 31, 32 coincide as shown in FIG. 5. Axis A and axis EX are also preferably contained in the first plane P1.

[0141] The axis F of the fan 12 is also preferably contained in plane P1, as also depicted in FIG. 5, however it does not coincide with the axes A, EX of the duct 18 and of the heat exchangers 31, 32. Preferably, the axis F of the fan is higher (e.g. above along a vertical axis) than the axes of the duct and of the heat exchangers (see FIG. 5).

[0142] Outside duct 18, in the first and second quarters Q1, Q2, at the two sides of the second portion 29 of the duct, where walls 18w1 and 18w2 are converging , the compressor 33 and the motor 50 are positioned. The converging shape of the duct allows an easy positioning of these elements.