Patent Publication Number: US-11659976-B2

Title: Dishwasher having condensing duct and return duct

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0137875, filed on Oct. 22, 2020, the disclosure of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to a dishwasher, and more particularly, to a dishwasher that improves drying performance and helps to prevent backflow of water by a simple configuration and at low cost, has a compact structure with a small size, and improves durability and stability. 
     BACKGROUND 
     A dishwasher is a household electrical appliance that may spray a washing liquid to washing targets such as dishes or cookware to remove foreign substances remaining on the washing targets. 
     In some cases, the dishwasher may include a tub configured to provide a washing space, a rack disposed in the tub and configured to accommodate dishes and the like, a spray arm configured to spray a washing liquid to the rack, a sump configured to store the washing liquid, and a washing pump configured to supply the spray arm with the washing liquid stored in the sump. 
     In some examples, the dishwasher may include a drying module. For example, the drying module may remove moisture remaining on the dish (a washing target or a drying target) by supplying heated air into the tub (a washing chamber). 
     The drying modules may be classified into an open-circulation drying module and a closed-circulation drying module. The open-circulation drying module may discharge moist air from the tub to the outside of the tub, heat outside air, and supply the heated air into the tub. The closed-circulation drying module may discharge moist air from the tub to the outside of the tub, remove moisture from the discharged air, and then supply the tub with the air from which the moisture is removed. 
     In some cases, the closed-circulation drying module may have better drying performance than the open-circulation drying module. But the manufacturing cost of the closed-circulation drying module may be higher than that of the open-circulation drying module. In some cases, the closed-circulation drying module may be installed in a wide installation space, which may limit reduction of a size of the dishwasher. Therefore, there is a need for a closed-circulation drying module capable of being simply manufactured at low cost, having a compact structure with a small size, and improving drying performance. 
     In some examples, the drying module may include a fan for allowing air to flow. In some cases, when water is introduced into a motor included in the fan, the fan may be broken down and may not perform the air-drying operation. Therefore, there is a need for a structure to help to prevent water from coming into contact with the fan. 
     In some examples, the drying module may include a heater for heating air. In some cases, when water is present at the periphery of the heater, the water may be vaporized into moisture vapor, and the moisture vapor may introduced into the tub, which may cause a deterioration in drying performance. Therefore, there is a need for a structure to help to prevent water from being present at the periphery of the heater. 
     In some cases, the fan or the heater may have a large size to effectively move or heat the air to improve the drying performance. Therefore, there is a need for a drying module that has a fan or a heater with a large size while the drying module having a compact structure with a small size. 
     In some examples, a dishwasher may include a drying system, in which air in a tub is discharged to the outside through a condensation assembly, and outside air is supplied into the tub through an assembly for blowing and heating drying air. The drying system may relate to the open-circulation drying module. 
     In some cases, a V-shaped flow tube may restrict water from coming into contact with a motor of the assembly for blowing and heating drying air. The V-shaped flow tube may have a long length and be installed in a large installation space, which limits reduction of a size of the drying module. 
     In some cases, where the length of the V-shaped flow tube is reduced to miniaturize the dishwasher, a size of a heater disposed in the V-shaped flow tube may decrease, which may lead to a decrease of an air heating area and a deterioration of a drying performance. 
     In some cases, water may be collected in an elbow portion of the V-shaped flow tube. In some cases, where the heater is disposed at the periphery of the elbow portion, the water may be vaporized into moisture vapor by the heater, and the moisture vapor may be introduced into the tub, which may lead to a deterioration of the drying performance. 
     SUMMARY 
     The present disclosure describes a dishwasher that can improve a drying performance by a simple configuration and at low cost. 
     The present disclosure also describes a dishwasher that can help to prevent water from flowing reversely. 
     The present disclosure further describes a dishwasher having a compact structure with a small size. 
     The present disclosure further describes a dishwasher that can reduce or prevent proliferation of bacteria or mold in a duct. 
     The present disclosure further describes a dishwasher having improved durability and stability. 
     The present disclosure further describes a dishwasher having an improved drying performance in spite of being provided with various components such as a washing pump and a sump lower than the bottom of a tub to reduce the installation space of the drying device. 
     According to one aspect of the subject matter described in this application, a dishwasher includes a tub having a washing space that is defined by a bottom portion of the tub, where the bottom portion defines an outlet port at a rear side thereof, an upper wall facing the bottom portion in a vertical direction, a rear wall facing a front side of the tub in a first direction, a first sidewall having an inlet port defined at a rear upper portion thereof, and a second sidewall facing the first sidewall in a second direction. The dishwasher further includes a door disposed at the front side of the tub and configured to open and close at least a portion of the washing space and a drying device configured to supply air to the washing space. The drying device includes a drying duct that is disposed outside the tub and in fluid communication with the inlet port and the outlet port, where the drying duct includes a condensing duct and a return duct. The drying device further includes a fan configured to cause a flow of air in the drying duct and a heater configured to heat the air in the drying duct. The condensing duct includes a first condensing duct that faces an outer surface of the first sidewall of the tub and has a first upstream end in fluid communication with the inlet port, and a second condensing duct that is disposed vertically below the bottom portion of the tub and has a second upstream end in fluid communication with a first downstream end of the first condensing duct. The return duct includes a return upstream end that is in fluid communication with a second downstream end of the second condensing duct, and a return downstream end that is in fluid communication with the outlet port. 
     Implementations according to this aspect can include one or more of the following features. For instance, the outlet port and the inlet port can be defined at positions on an imaginary vertical plane that extends in the second direction and the vertical direction. In some examples, the second condensing duct can be curved at the second downstream end and extend in the vertical direction. In some examples, a horizontal distance between the second upstream end and the second downstream end can be greater than a horizontal distance between the second upstream end and the outlet port. 
     In some implementations, the second condensing duct and the return duct can be positioned vertically below a rear portion of the bottom portion of the tub. In some examples, the return duct can be positioned between the bottom portion of the tub and the second condensing duct. In some examples, at least a portion of the return duct can face and extend along the second condensing duct in a longitudinal direction of the second condensing duct, and the drying device can further include a separation wall that is disposed at least the portion of the return duct. For example, the separation wall can be disposed between the return duct and the second condensing duct and extending in the longitudinal direction. In some examples, the separation wall can define a water drain hole in fluid communication with the return duct and the second condensing duct. 
     In some implementations, the fan and the heater can be disposed between the second downstream end of the second condensing duct and the return downstream end of the return duct. For example, the heater can be disposed in the return duct. In some examples, the fan can be disposed vertically above the second downstream end of the second condensing duct and in fluid communication with the return duct. 
     In some implementations, the fan can include a fan blade, a motor disposed vertically above the fan blade and configured to rotate the fan blade, and a fan housing that accommodates the fan blade, where the fan housing includes a housing upper wall that is disposed between the fan blade and the motor and that faces the second downstream end of the second condensing duct and the return upstream end of the return duct. In some implementations, the fan can include a rotary shaft that extends in the vertical direction. 
     In some implementations, the first downstream end of the first condensing duct can be positioned at a lower end of a rear portion of the first sidewall, and the second upstream end of the second condensing duct can be positioned at a side end of a rear portion of the bottom portion of the tub. 
     In some implementations, the dishwasher can include a cold air supply module that is disposed outside the tub and at least partially overlap with the first condensing duct. For example, the cold air supply module can include a first outside air inflow duct disposed vertically below the bottom portion of the tub and configured to receive air from an outside of the drying device, a second outside air inflow duct that faces the outer surface of the first sidewall and is in fluid communication with a downstream end of the first outside air inflow duct, and a heat exchange flow path part that is connected to the first condensing duct and in fluid communication with a downstream end of the second outside air inflow duct. 
     In some examples, the dishwasher can further include a cooling fan that is disposed in the first outside air inflow duct or an upstream end of the first outside air inflow duct, where the cooling fan is configured to draw air from the outside toward the first outside air inflow duct. In some examples, the heat exchange flow path part can extend along an outer circumferential surface of the first condensing duct and have a downstream end configured to discharge air to an outside of the drying device, where the downstream end of the heat exchange flow path part faces and is spaced apart from an end of the first condensing duct in the second direction. 
     In some implementations, the inlet port can be configured to receive air and moisture from the washing space and to supply the air and the moisture to the first condensing duct, where the first condensing duct is configured to guide the air and the moisture from the first upstream end to the first downstream end. The second condensing duct can be configured to receive the air and the moisture from the first condensing duct through the second upstream end and to guide the air and the moisture to the second downstream end. In some examples, the heater can be disposed in the return duct, and the return duct can be configured to guide air heated by the heater toward the return downstream end, where the outlet port is configured to receive the heated air from the return duct and to supply the heated air to the washing space. 
     In some implementations, where the outlet port meets an imaginary vertical surface that passes through the inlet port and extends in the second direction and the vertical direction, the horizontal distance between the outlet port formed in the bottom of the tub and the inlet port formed in one sidewall of the tub can be minimized. Therefore, the dry air introduced into the washing space through the outlet port can effectively circulate everywhere in the washing space until the dry air is introduced into the drying device through the inlet port. Therefore, the drying efficiency can be further improved. 
     In some implementations, where the second condensing duct is bent in the vicinity of a downstream end and extend in the vertical direction (e.g., upward), it can be possible to help to prevent the water, which is introduced into the second condensing duct or produced in the second condensing duct, from being introduced into the return duct. 
     In some implementations, where the outlet port is formed in the vicinity of the inlet port in the horizontal direction to improve the drying performance, a horizontal length of the return duct communicating with the outlet port and the downstream end of the second condensing duct can increase. In some examples, a distance between the downstream end of the second condensing duct and the upstream end of the return duct can increase. 
     In some implementations, a heater can have a large size and be disposed inside or outside the return duct, and the fan can be disposed between the upstream end of the return duct and the downstream end of the second condensing duct. Therefore, the drying performance of the dishwasher can be improved by the simple configuration, and the dishwasher can have a compact structure having a small size. 
     In some implementations, the second condensing duct and the return duct can be positioned only under rear portions of the bottom of the tub. Therefore, since the second condensing duct and the return duct are positioned at the rear side together with the outlet port and the inlet port, the second condensing duct and the return duct can be formed in a shape similar to a straight line, and the lengths of the ducts, and can decrease. Therefore, the flow resistance can be reduced, and the drying performance can be improved. In addition, the dishwasher can have a compact structure having a small size. 
     In some implementations, the return duct can be positioned between the bottom of the tub and the second condensing duct. Therefore, it can be possible to help to prevent the water introduced into the second condensing duct through the inlet port and the water condensed in the condensing duct from being introduced into the return duct. Therefore, it can be possible to help to prevent the water in the condensing duct from being introduced into the washing space S through the outlet port communicating with the return duct, thereby improving the drying performance. 
     In some implementations, the return duct and the second condensing duct can at least partially adjoin each other in the longitudinal direction of the return duct and the second condensing duct. At the portion where the return duct and the second condensing duct adjoin each other, the return duct and the second condensing duct can be separated by a separation wall W disposed in the longitudinal direction of the return duct and the second condensing duct. Therefore, the return duct and the second condensing duct can be easily manufactured by the simple configuration and at low cost. In addition, since the return duct and the second condensing duct are separated by the single separation wall, a part of heat generated from the heater disposed in the return duct can be easily transferred to the second condensing duct. Therefore, a small amount of water in the second condensing duct is vaporized by the heat transferred to the second condensing duct, and thus the humidity in the second condensing duct decreases, which makes it possible to help to prevent the proliferation of bacteria or mold in the second condensing duct. 
     In some implementations, the fan and the heater is disposed between the downstream end of the condensing duct and the downstream end of the return duct. Therefore, the fan can allow the air to smoothly flow in the downstream portion (e.g., between the condensing duct and the return duct) of the drying duct where the flow direction of the air is considerably changed, thereby reducing the flow resistance. Further, the heater can heat the air in the downstream portion (e.g., the return duct) of the drying duct close to the outlet port and discharge the high-temperature dry air into the washing space. As a result, it can be possible to improve the drying performance by the simple configuration and at low cost. 
     In some implementations, the heater can be disposed in the return duct. Therefore, since the high-temperature air, which is heated in the return duct close to the outlet port, flows into the washing space, the heated air flowing into the washing space can effectively remove moisture remaining on dishes in the washing space. Therefore, the drying performance can be improved by the simple structure and at low cost. In addition, since the heater does not come into contact with the water introduced into the condensing duct or the water condensed in the condensing duct, it can be possible to help to prevent the heat generated by the heater from vaporizing a large amount of water collected in the condensing duct. Therefore, the high-temperature dry air in the return duct can flow into the washing space, thereby improving the drying performance. 
     In some implementations, the fan can be disposed higher than the downstream end of the second condensing duct. Therefore, it can be possible to help to prevent a motor of the fan from coming into contact with the water introduced into the condensing duct or the water condensed in the condensing duct. Therefore, it can be possible to help to prevent the water from being introduced into the motor of the fan and thus help to prevent the fan from being broken down, thereby improving the durability and stability of the drying device. 
     In some implementations, the motor can be disposed above the fan blade, and the fan housing can include the upper wall disposed between the fan blade and the motor. Therefore, even though the fan blade comes into contact with the water introduced into the return duct through the outlet port, the water being in contact with the fan blade is blocked by the upper wall, such that the water cannot come into contact with the motor. Therefore, it can be possible to help to prevent the water from being introduced into the motor and thus help to prevent the fan from being broken down, thereby improving the durability and stability of the drying device. 
     In some implementations, the rotary shaft of the fan can extend in the vertical direction. Therefore, the fan can be installed to be laid between the second condensing duct and the return duct. Therefore, the fan having a sufficiently large size can be installed even though the installation space or the installation position is restricted. Therefore, the drying performance of the dishwasher can be improved by the simple configuration and at low cost, and the dishwasher can have a compact structure having a small size. In addition, since the motor can be disposed above the fan blade, it can be possible to help to prevent the water from being introduced into the motor. 
     In some implementations, the downstream end of the first condensing duct can be positioned in the vicinity of the lower end of the rear portion of one sidewall, and the upstream end of the second condensing duct can be positioned in the vicinity of one side end of the rear portion of the bottom. Therefore, since both the downstream end of the first condensing duct and the upstream end of the second condensing duct are positioned at the rear side together with the inlet port and the outlet port, the condensing duct can be formed in a shape similar to a straight line, and the length of the condensing duct can decrease. Therefore, the flow resistance can be reduced, and the drying performance can be improved. 
     In some implementations, the dishwasher can further include the cold air supply module disposed outside the tub and configured to at least partially adjoin the first condensing duct. Therefore, the cold air supply module can effectively remove moisture vapor, which is contained in the air flowing along the first condensing duct, by condensing the moisture vapor into the water. Therefore, the drying performance can be improved by the simple structure and at low cost. 
     In some implementations, the cold air supply module can include the first outside air inflow duct disposed lower than the bottom and configured to allow the outside air to be introduced thereinto, the second outside air inflow duct configured to face or adjoin the outer surface of one sidewall, and the heat exchange flow path part configured to adjoin the first condensing duct and communicate with the second outside air inflow duct. Therefore, it can be possible to effectively remove moisture vapor, which is contained in the air flowing along the first condensing duct, by condensing the moisture vapor into the water with the cold air lower than the tub. Therefore, the drying performance can be improved by the simple structure and at low cost. 
     In some implementations, the cooling fan can be disposed in the first outside air inflow duct or at the periphery of the upstream end of the first outside air inflow duct. Therefore, since the cooling fan can be disposed lower than the tub, the cooling fan can suction the cold air lower than the tub and supply the cold air to the heat exchange flow path part, thereby improving the cooling efficiency. In addition, because the space lower than the tub is comparatively large, it can be possible to improve the cooling efficiency by increasing the size of the cooling fan. 
     In some implementations, the heat exchange flow path part can extend along the outer circumferential surface of the first condensing duct, and the downstream end of the heat exchange flow path part can be positioned in parallel in the second direction with the end in the width direction of the first condensing duct. The air can be discharged to the outside through the downstream end of the heat exchange flow path part. Therefore, the heat exchange flow path part can be configured and the installation space of the heat exchange flow path part can be minimized by the simple configuration and at low cost. In addition, a length of the heat exchange flow path part is decreased, and the flow resistance is reduced, such that the cooling performance can be improved. 
     The specific effects of the present disclosure, together with the above-mentioned effects, will be described along with the description of specific items for carrying out the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a cross-sectional view illustrating an example of a dishwasher. 
         FIG.  2    is a perspective view illustrating an example of a tub. 
         FIGS.  3  to  6    are a perspective view, a front view, a side view, and a top plan view illustrating an example of a drying device and the tub. 
         FIG.  7    is a perspective view illustrating an example of a drying device. 
         FIG.  8    is a view illustrating example components of the drying device in  FIGS.  3  to  7    that are integrally manufactured. 
         FIG.  9    is a perspective view illustrating examples of a heat exchange duct and a heat exchange flow path part disposed between a first upstream duct and a first downstream duct in the structure illustrated in  FIG.  8   . 
         FIG.  10    is a perspective view illustrating examples of a second connection duct, a second condensing duct, a return duct, a fan housing, a heater, and a distributor. 
         FIGS.  11  to  13    are a perspective view, a top plan view, and a cross-sectional view illustrating a second downstream duct, the return duct, the fan housing, and the heater. 
         FIG.  14    is an exploded perspective view illustrating the second downstream duct, the return duct, the fan housing, the heater, and the distributor. 
         FIG.  15    is a cross-sectional view illustrating examples of a fan blade and a motor that are installed in the fan housing illustrated in  FIG.  13   . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, one or more implementations of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar constituent elements. 
     For the convenience of description, a direction toward a front surface or a rear surface of a door of a dishwasher in a state in which the door is closed is defined as a first direction or a forward/rearward direction. 
     A second direction or a leftward/rightward direction can mean a direction toward left and right sides in the drawings illustrating a front surface of the door in the closed state. 
     Hereinafter, a dishwasher according to one or more implementations of the present disclosure will be described. 
       FIG.  1    is a cross-sectional view illustrating an example of a dishwasher. 
     In some implementations, referring to  FIG.  1   , the dishwasher  1  can include a cabinet  11 , the tub  12 , a plurality of spray arms  23 ,  24 , and  25 , a sump  50 , a filter  70 , a washing pump  80 , a switching valve  85 , a water supply valve  32 , a water drain pump  35 , and a drying device  100 . The respective components will be described. 
     The cabinet  11  can define an external appearance of the dishwasher  1 . 
     The tub  12  can be disposed in the cabinet  11 . In some examples, the tub  12  can have a hexahedral shape opened at a front side thereof. However, the shape of the tub  12  is not limited thereto, and the tub  12  can have various shapes. 
     A washing space  12 S can be defined in the tub  12  and accommodate a washing target. A door  14  ( FIG.  2   ) for opening or closing the washing space  12 S can be provided at a front side of the tub  12 . 
     In some implementations, an inlet port H 1  and an outlet port H 2 , which communicate with the drying device  100 , can be defined in the sidewall  12 R and a bottom  12 B of the tub  12 . In addition, the bottom  12 B of the tub  12  has a communication hole H 3  through which a washing liquid is introduced into the sump  50 . 
     The door  14  ( FIG.  2   ) can be disposed at the front side of the tub  12  and open or close the washing space  12 S. 
     A plurality of racks  26  and  27  for accommodating the washing targets such as dishes can be disposed in the washing space  12 S. The plurality of racks  26  and  27  can include a lower rack  26  disposed at a lower side of the washing space  12 S, and an upper rack  27  disposed at an upper side of the washing space  12 S. The lower rack  26  and the upper rack  27  can be disposed to be spaced apart from each other vertically and withdrawn toward a location in front of the tub  12  by sliding. 
     The plurality of spray arms  23 ,  24 , and  25  can be disposed to be spaced apart from one another vertically. The plurality of spray arms  23 ,  24 , and  25  can include a low spray arm  23 , an upper spray arm  24 , and a top spray arm  25 . The low spray arm  23  can spray the washing liquid upward toward the lower rack  26 . The upper spray arm  24  can be disposed above the low spray arm  23  and spray the washing liquid upward toward the upper rack  27 . The top spray arm  25  can be disposed at an uppermost end of the washing space  12 S and spray the washing liquid downward. 
     The plurality of spray arms  23 ,  24 , and  25  can be supplied with the washing liquid from the washing pump  80  through the plurality of spray arm connecting flow tubes  28 ,  29 , and  31 . 
     The sump  50  can be provided lower than the bottom  12 B of the tub  12  and collect and store the washing liquid. Specifically, the sump  50  can be connected to a water supply flow path  33  and supplied with the clean washing liquid including no foreign substances through the water supply flow path  33 , and the sump  50  can store the clean washing liquid. In addition, the sump  50  can be supplied with and store the washing liquid from which foreign substances are removed by the filter  70 . 
     The filter  70  can be disposed in the sump  50  and installed in the communication hole H 3 . The filter  70  can filter out foreign substances from the washing liquid containing foreign substances and moving from the tub  12  to the sump  50 . 
     The water supply valve  32  can control the washing liquid supplied from a water source through the water supply flow path  33 . When the water supply valve  32  is opened, the washing liquid supplied from the external water source can be introduced into the sump  50  through the water supply flow path  33 . 
     A water drain flow path  34  can be connected to the water drain pump  35  and the sump  50 . 
     The water drain pump  35  can be connected to the water drain flow path  34  and include a water drain motor. 
     When the water drain pump  35  operates, the foreign substances filtered out by the filter  70  or the washing liquid can be discharged to the outside through the water drain flow path  34 . 
     The washing pump  80  can be disposed below the bottom  12 B of the tub  12  and supply the plurality of spray arms  23 ,  24 , and  25  with the washing liquid stored in the sump  50 . 
     The switching valve  85  can selectively connect at least one of the plurality of spray arms  23 ,  24 , and  25  to the washing pump  80 . 
     The drying device  100  can be disposed beside one sidewall  12 R and lower than the bottom  12 B of the tub  12 . The drying device  100  can communicate with the inside of the washing space  12 S through the inlet port H 1  and the outlet port H 2 . The drying device  100  can dry the washing space  12 S in the tub  12 . 
     In a drying step of the dishwasher  1 , the moist air in the washing space  12 S can be introduced into the drying device  100  through the inlet port H 1 , and the air dried by the drying device  100  can be introduced into the washing space  12 S through the outlet port H 2 . The circulation of the air can be repeatedly performed. The drying device  100  can improve drying performance through the closed circulation of the air. 
     In some examples, a space capable of installing the drying device  100  can be narrow because various components, such as the washing pump  80 , which constitute the dishwasher  1 , are installed below the bottom  12 B of the tub  12  and the sump  50  is provided lower than the bottom  12 B of the tub  12 . Therefore, the drying device  100  needs to have a compact structure having a small size so that the drying device  100  can be installed in the dishwasher  1 . 
     A distributor  150  of the drying device  100  can be inserted into the washing space  12 S through the outlet port H 2 . The distributor  150  can be disposed at an edge corner of the tub  12  so as not to collide with the rotating spray arm  23 . 
       FIG.  2    is a perspective view illustrating an example of the tub,  FIGS.  3  to  6    are a perspective view, a front view, a side view, and a top plan view illustrating an example of a drying device and the tub, and  FIG.  7    is a perspective view illustrating the drying device. 
     In some implementations, referring to  FIG.  2   , the tub  12  can include the bottom  12 B, an upper wall  12 T, a first sidewall  12 R, a second sidewall  12 L, and the rear wall  12 RR. The washing space  12 S can be defined in the tub  12  by the bottom  12 B, the upper wall  12 T, the first sidewall  12 R, the second sidewall  12 L, and the rear wall  12 RR. For example, the first sidewall  12 R can be a right sidewall of the tub  12 , and the second sidewall  12 L can be a left sidewall of the tub  12 . 
     The door  14  for opening or closing the washing space  12 S can be disposed at the front side of the tub  12 . 
     The bottom  12 B and the upper wall  12 T can face each other in the vertical direction, the rear wall  12 RR and the door  14  can face each other in the first direction, and one sidewall  12 R and the other sidewall  12 L can face each other in the second direction. 
     One sidewall  12 R of the tub  12  can be divided into rear portions R 11 , R 12 , and R 13 , central portions R 21 , R 22 , and R 23 , and front portions R 31 , R 32 , and R 33  in the first direction or the forward/rearward direction. A point at which the rear portion and the central portion of one sidewall  12 R are separated can be a point of about ¼ to ⅓ of a width of one sidewall  12 R from a rear end to a front side of one sidewall  12 R. A point at which the front portion and the central portion of one sidewall  12 R are separated can be a point of about ¼ to ⅓ of the width of one sidewall  12 R from a front end to a rear side of one sidewall  12 R. 
     In addition, one sidewall  12 R of tub  12  can be divided into upper portions R 11 , R 21 , and R 31 , central portions R 12 , R 22 , and R 32 , and lower portions R 13 , R 23 , and R 33  in the vertical direction or an upward/downward direction. A point at which the upper portion and the central portion of one sidewall  12 R are separated can be a point of about ¼ to ⅓ of a height of one sidewall  12 R from an upper end to a lower side of one sidewall  12 R. A point at which the lower portion and the central portion of one sidewall  12 R are separated can be a point of about ¼ to ⅓ of the height of one sidewall  12 R from a lower end to an upper side of one sidewall  12 R. 
     Therefore, one sidewall  12 R of the tub  12  can be divided into nine regions including a rear upper portion R 11 , a rear central portion R 12 , a rear lower portion R 13 , a central upper portion R 21 , a central portion R 22 , a central lower portion R 23 , a front upper portion R 31 , a front central portion R 32 , and a front lower portion R 33  in the first direction and the vertical direction. 
     Like one sidewall  12 R, the bottom  12 B of the tub  12  can also be divided into nine regions including one rear side portion B 11 , a rear central portion B 12 , the other rear side portion B 13 , one central side portion B 21 , a central portion B 22 , the other central side portion B 23 , one front side portion B 31 , a front central portion B 32 , and the other front side portion B 33  in the first direction and the second direction. 
     The inlet port H 1  through which the air in the washing space  12 S is introduced into the drying duct  110  can be formed in the rear upper portion R 11  of one sidewall  12 R of the tub  12 . In addition, the outlet port H 2  through which the air in the drying duct  110  is discharged to the washing space  12 S can be formed in one rear side portion B 11  of the bottom  12 B of the tub  12 . 
     Therefore, since both the outlet port H 2  and the inlet port H 1  are formed in one rear side of the tub  12 , a horizontal distance between the outlet port H 2  and the inlet port H 1  can decrease. In addition, since the outlet port H 2  is formed in the bottom  12 B and the inlet port H 1  is formed in the upper portion of one sidewall  12 R, a vertical distance between the outlet port H 2  and the inlet port H 1  can increase. 
     In some examples, to introduce the air into the specific space and allow the introduced air to effectively circulate in the space, i) the air introduced into the inlet port can be restricted from flowing directly to the outlet port, and ii) the horizontal distance between the air inlet port and the outlet port can be decreased, and the vertical distance between the inlet port and the outlet port can be increased. 
     As described above, since the condition ii) is satisfied, the dry air introduced into the washing space  12 S through the outlet port H 2  can effectively circulate everywhere in the washing space  12 S until the dry air is introduced into the drying device  100  through the inlet port H 1 , thereby improving the drying efficiency. In some examples, the condition i) can be provided by the distributor  150 . 
     In addition, since both the outlet port H 2  and the inlet port H 1  are formed at the rear side of the tub  12 , the drying duct  110  can be disposed at the periphery of the rear side of the tub  12 , and a cold air supply module  120  can be disposed at the periphery of the front side of the tub  12 . The periphery of the rear side of the tub  12  can be blocked approximately by the wall, and the periphery of the front side of the tub  12  (particularly, the front space lower than the tub) is opened forward, such that a temperature of the air at the periphery of the front side of the tub  12  can be lower. Therefore, the cold air supply module  120  can effectively reduce humidity of the air in the drying duct  110  by using the cold air at the periphery of the front side of the tub  12 , thereby improving the drying performance. 
     In addition, since the outlet port H 2  is formed at the rear side of the tub  12 , the distributor  150  of the drying device  100  can be disposed at the rear side of the tub  12 . Therefore, when the door  14  disposed at the front side of the tub  12  is opened, the distributor  150  of the drying device  100  does not obstruct a visual field. Therefore, it can be possible to improve the aesthetic appearance and easily manage various types of devices in the tub  12  without being hindered by the distributor  150  of the drying device  100 . 
     The outlet port H 2  can meet an imaginary vertical surface S that passes through the inlet port H 1  and extends in the second direction and the vertical direction. For example, a center of the outlet port H 2  can meet the imaginary vertical surface S that passes through a center of the inlet port H 1  and extends in the second direction. The configuration in which the outlet port H 2  meets the vertical surface S will be described below. 
     The outlet port H 2 , which has a minimum value of the horizontal distance from the inlet port H 1  among the outlet ports H 2  formed in the bottom  12 B and spaced apart from one side end of the bottom  12 B toward the other side (the other side in the second direction) by a particular distance, is the outlet port H 2  that meets the imaginary vertical surface S. 
     When the outlet port H 2  meets the vertical surface S, the horizontal distance between the outlet port H 2  formed in the bottom  12 B of the tub  12  and the inlet port H 1  formed in one sidewall  12 R of the tub  12  can be minimized, so the condition ii) cab be partially provided. Therefore the dry air introduced into the washing space  12 S through the outlet port H 2  can effectively circulate everywhere in the washing space  12 S until the dry air is introduced into the drying device  100  through the inlet port H 1 . Therefore, the drying efficiency can be further improved. 
     Further referring to  FIGS.  3  to  7   , the drying device  100  can include the drying duct  110 , the cold air supply module  120 , a fan  130 , a heater  140 , and the distributor  150 . However, the cold air supply module  120  and the distributor  150  can be omitted from the drying device  100 . The respective components will be described. 
     The drying duct  110  communicates with the inlet port H 1  and the outlet port H 2  and is disposed outside the tub  12 . The drying duct  110  can include the condensing duct  112  and a return duct  114 . 
     Therefore, because the condensing duct  112  adjoins low-temperature outside air outside the tub  12 , moisture vapor contained in the air flowing along the condensing duct  112  is condensed into water and then removed. Therefore, the drying performance can be improved by the simple structure and at low cost. 
     The condensing duct  112  can include the first condensing duct  1122  and a second condensing duct  1124 . 
     The first condensing duct  1122  can be disposed on one sidewall  12 R. Specifically, the first condensing duct  1122  can face or adjoin the outer surface or the outer circumferential surface of one sidewall  12 R. An upstream end  1122 U of the first condensing duct  1122  can communicate with the inlet port H 1 . 
     Therefore, the condensing duct  112  adjoins the low-temperature air outside one sidewall  12 R the tub  12 , such that the moisture vapor contained in the air flowing along the condensing duct  112  is condensed into water and then removed. Therefore, the drying performance can be improved by the simple structure and at low cost. 
     Specifically, for example, the first condensing duct  1122  can include a first upstream duct  1122 A, a heat exchange duct  1122 B, and a first downstream duct  1122 C sequentially disposed along the flow direction of the air ( FIGS.  5  and  7   ). The first upstream duct  1122 A, the heat exchange duct  1122 B, and the first downstream duct  1122 C can be three duct sections of the first condensing duct  1122 . 
     The first upstream duct  1122 A can communicate with the inlet port H 1 , and the air can be introduced into the first upstream duct  1122 A. 
     The heat exchange duct  1122 B can adjoin the cold air supply module  120 . 
     The first downstream duct  1122 C can communicate with the second condensing duct  1124  and discharge the air to the second condensing duct  1124 . 
     A first water drain port D 1  can be formed in the first downstream duct  1122 C. Therefore, the water introduced through the inlet port H 1  or the water condensed in the heat exchange duct  1122 B can be discharged to the outside through the first water drain port D 1 , thereby improving the drying performance of the drying device  100 . 
     A suction fan can be provided at the upstream end  1122 U or the periphery of the upstream end  1122 U of the first condensing duct  1122 . The suction fan can be a centrifugal fan. The suction fan can improve the drying performance by allowing the air to smoothly flow. Since the centrifugal fan is provided, a transverse width (i.e. width in the second direction in the drawings) of the first condensing duct  1122  can be minimized, thereby miniaturizing the dishwasher  1 . 
     A downstream end  1122 D of the first condensing duct  1122  can be positioned in the vicinity of a lower end of the rear portion of one sidewall  12 R of the tub  12 . In this regard, this configuration will be described. 
     The cold air supply module  120  related to the first condensing duct  1122  will be described first, and then the second condensing duct  1124  will be described. 
     The cold air supply module  120  can be disposed outside the tub  12 . At least a part of the cold air supply module  120  can adjoin the first condensing duct  1122 . 
     Specifically, for example, the cold air supply module  120  can include a first outside air inflow duct  122 , a second outside air inflow duct  124 , and a heat exchange flow path part  126  ( FIGS.  5  and  7   ). 
     The first outside air inflow duct  122  can be disposed lower than the bottom  12 B of the tub  12 , and outside air can be introduced through an upstream end  122 U. 
     The second outside air inflow duct  124  can face or adjoin an outer surface of one sidewall  12 R of the tub  12 . An upstream end  124 U can communicate with a downstream end  122 D of the first outside air inflow duct  122 . 
     The heat exchange flow path part  126  can adjoin the first condensing duct  1122 , and an upstream end  126 U of the heat exchange flow path part  126  can communicate with a downstream end  124 D of the second outside air inflow duct  124 . 
     Specifically, for example, the heat exchange flow path part  126  can extend along an outer circumferential surface of the first condensing duct  1122 . A downstream end  126 D of the heat exchange flow path part  126  can be positioned approximately in parallel in the second direction with an end  1122 E in a width direction (the first direction in the drawings) of the first condensing duct  1122  ( FIGS.  7  and  9   ). The air can be discharged to the outside through the downstream end  126 D of the heat exchange flow path part  126 . 
     Therefore, the heat exchange flow path part  126  can be configured and the installation space of the heat exchange flow path part  126  can be minimized by the simple configuration and at low cost. In addition, a length of the heat exchange flow path part  126  is decreased, and the flow resistance is reduced, such that the cooling performance can be improved. 
     The cooling fan  128  can be disposed in the first outside air inflow duct  122  or at the periphery of the upstream end  122 U of the first outside air inflow duct  122 . The cooling fan  128  can suction the outside air and supply the outside air into the heat exchange flow path part  126 . 
     Therefore, since the cooling fan  128  can be disposed lower than the tub  12 , the cooling fan  128  can suction the cold air lower than the tub  12  and supply the cold air to the heat exchange flow path part  126 , thereby improving the cooling efficiency. In addition, because the space lower than the tub  12  is comparatively large, it can be possible to improve the cooling efficiency by increasing the size of the cooling fan  128 . 
     In some examples, a first connection duct  123  can be disposed between the first outside air inflow duct  122  and the second outside air inflow duct  124 . The first connection duct  123  can communicate with the downstream end  122 D of the first outside air inflow duct  122  and the upstream end  124 U of the second outside air inflow duct  124  ( FIG.  7   ). 
     As described above, the dishwasher can further include the cold air supply module  120  disposed outside the tub  12  and configured to at least partially adjoin the first condensing duct  1122 . Therefore, the cold air supply module  120  can effectively remove moisture vapor, which is contained in the air flowing along the first condensing duct  1122 , by condensing the moisture vapor into the water. Therefore, the drying performance can be improved by the simple structure and at low cost. 
     In addition, the cold air supply module  120  includes the first outside air inflow duct  122  disposed lower than the bottom  12 B of the tub  12  and configured to allow the outside air to be introduced thereinto, the second outside air inflow duct  124  configured to face or adjoin the outer surface or the outer surface of one sidewall  12 R of the tub  12 , and the heat exchange flow path part  126  configured to adjoin the first condensing duct  1122  and communicate with the second outside air inflow duct  124 . Therefore, it can be possible to effectively remove the moisture vapor contained in the air flowing along the first outside air inflow duct  122  by condensing the moisture vapor into water using the cold air lower than the tub  12 . Therefore, the drying performance can be improved by the simple structure and at low cost. 
     The heat exchange flow path part  126  will be described in more detail with reference to  FIGS.  8  and  9   . 
       FIG.  8    is a view illustrating example components of the drying device in  FIGS.  3  to  7    that are integrally manufactured, and  FIG.  9    is a perspective view illustrating examples of a heat exchange duct and a heat exchange flow path part disposed between a first upstream duct and a first downstream duct in the structure illustrated in  FIG.  8   . 
     In some implementations, referring to  FIG.  8   , the first upstream duct  1122 A, the first downstream duct  1122 C, and the second outside air inflow duct  124  can be integrated. A vacant space can be formed between the first upstream duct  1122 A and the first downstream duct  1122 C. The heat exchange duct  1122 B and the heat exchange flow path part  126 , which will be described with reference to  FIG.  9   , can be installed in the vacant space between the first upstream duct  1122 A and the first downstream duct  1122 C. 
     Since the first upstream duct  1122 A, the first downstream duct  1122 C, and the second outside air inflow duct  124  are integrated as described above, the manufacturing cost of the drying device  100  can be reduced, and the drying device  100  can be easily installed and maintained. 
     Referring to  FIG.  9   , the heat exchange duct  1122 B and the heat exchange flow path part  126  can be installed between the first upstream duct  1122 A and the first downstream duct  1122 C in the structure illustrated in  FIG.  8   . 
     The heat exchange duct  1122 B can have a flat tubular shape opened at two opposite ends thereof and communicate vertically with the first upstream duct  1122 A and the first downstream duct  1122 C illustrated in  FIG.  8   . 
     The heat exchange flow path part  126  can include a plate  1262  and a partition wall  1264 . 
     The plate  1262  can be disposed to face at least one of one surface and the other surface in the second direction of the heat exchange duct  1122 B. 
     The partition wall  1264  can be provided in plural, and the plurality of partition walls  1264  can be disposed in parallel between the plate  1262  and one surface or the other surface in the second direction of the heat exchange duct  1122 B. 
     The plate  1262  and the plurality of partition walls  1264  can extend along the outer circumferential surface of the heat exchange duct  1122 B in the width direction (the first direction in the drawings) of the heat exchange duct  1122 B that intersects the flow direction of the air flowing in the heat exchange duct  1122 B. 
     When the heat exchange duct  1122 B and the heat exchange flow path part  126  illustrated in  FIG.  9    are installed in the vacant space between the first upstream duct  1122 A and the first downstream duct  1122 C of the structure illustrated in  FIG.  8   , the downstream end  124 D of the second outside air inflow duct  124  can adjoin a lateral end in the first direction of the heat exchange duct  1122 B and the plate  1262 . Therefore, the cold air introduced into the second outside air inflow duct  124  can flow to the vacant space between the plate  1262  and the heat exchange duct  1122 B. In this case, a plurality of flow paths can be formed between the plate  1262  and the heat exchange duct  1122 B by the plurality of partition walls  1264  extending in the width direction (the first direction in the drawings) of the heat exchange duct  1122 B. 
     That is, the cold air introduced into the second outside air inflow duct  124  can flow along the plurality of flow paths formed by the heat exchange duct  1122 B, the plate  1262 , and the plurality of partition walls  1264 . The direction in which the cold air flows along the plurality of flow paths formed by the heat exchange flow path part  126  can intersect the direction in which the moist air flows along the heat exchange duct  1122 B. 
     In this case, as described above, the downstream end  126 D of the heat exchange flow path part  126  can be positioned approximately in parallel in the second direction with the end  1122 E in the width direction (the first direction in the drawings) of the first condensing duct  1122  ( FIG.  9   ). 
     As described above, the heat exchange flow path part  126  includes the plate  1262  disposed to face at least one of one surface and the other surface in the second direction of the heat exchange duct  1122 B, and the plurality of partition walls  1264  disposed in parallel between the plate  1262  and one surface or the other surface in the second direction of the heat exchange duct  1122 B. Therefore, heat exchange flow path part  126  can be configured by the simple configuration and at low cost. In addition, since the cold air flows along the outer circumferential surface of the heat exchange duct  1122 B, the heat exchange efficiency can be improved. In addition, since the cold air flows along the plurality of flow paths separated from one another, the heat exchange is uniformly performed in a wide area, such that the heat exchange efficiency can be improved. 
     In some examples, as illustrated in  FIG.  9   , since the heat exchange duct  1122 B and the heat exchange flow path part  126  are manufactured separately and then installed between the first upstream duct  1122 A and the first downstream duct  1122 C of the structure illustrated in  FIG.  8   , the drying device  100  can be easily manufactured, replaced, and repaired. Therefore, the manufacturing cost can be reduced, and the maintenance can be easily performed. 
       FIG.  10    is a perspective view illustrating examples of a second connection duct, a second condensing duct, a return duct, a fan housing, a heater, and a distributor, and  FIGS.  11  to  13    are a perspective view, a top plan view, and a cross-sectional view illustrating examples of a second downstream duct, the return duct, the fan housing, and the heater.  FIG.  14    is an exploded perspective view illustrating examples of the second downstream duct, the return duct, the fan housing, the heater, and the distributor.  FIG.  15    is a cross-sectional view illustrating examples of a fan blade and a motor that are installed in the fan housing illustrated in  FIG.  13   . 
     Further referring to  FIGS.  10  to  15   , the second condensing duct  1124  can be disposed lower than the bottom  12 B of the tub  12 . An upstream end  1124 U of the second condensing duct  1124  can communicate with the downstream end  1122 D of the first condensing duct  1122  ( FIGS.  5  and  7   ). 
     Therefore, the condensing duct  112  adjoins the low-temperature air lower than the bottom  12 B of the tub  12 , such that the moisture vapor contained in the air flowing along the condensing duct  112  is condensed into water and then removed. Therefore, the drying performance can be improved by the simple structure and at low cost. 
     Specifically, for example, the second condensing duct  1124  can include a second upstream duct  1124 A and a second downstream duct  1124 B sequentially disposed along the flow direction of the air ( FIGS.  7  and  10   ). The second upstream duct  1124 A and the second downstream duct  1124 B can be two duct sections of the second condensing duct  1124 . 
     The second upstream duct  1124 A can communicate with the downstream end  1122 D of the first condensing duct  1122  ( FIGS.  5 ,  7 , and  10   ). The second upstream duct  1124 A can be inclined approximately downward along the flow direction of the air. 
     The second downstream duct  1124 B can communicate with the return duct  114 . The second downstream duct  1124 B can be approximately parallel to the horizontal plane or inclined upward along the flow direction of the air. 
     However, the present disclosure is not limited to this configuration. For example, the second condensing duct  1124  can be configured to include only a section parallel to the horizontal plane or inclined upward like the second downstream duct  1124 B. In this case, the second downstream duct  1124 B can be the second condensing duct  1124 . 
     The second condensing duct  1124  can be bent in the vicinity of a downstream end  1124 D and extend in an approximately vertical direction (e.g., upward). Therefore, it can be possible to help to prevent the water, which is introduced into the second condensing duct  1124  or produced in the second condensing duct  1124 , from being introduced into the return duct  114 . 
     The horizontal straight distance d 1  between the upstream end  1124 U and the downstream end  1124 D of the second condensing duct  1124  can be longer than a horizontal straight distance d 2  between the upstream end  1124 U of the second condensing duct  1124  and the outlet port H 2  ( FIG.  6   ). For example, in the second direction, the downstream end  1124 D of the second condensing duct  1124  can be located beyond a midpoint of the bottom  12 B of the tub  12  ( FIG.  6   ). 
     Therefore, even though the outlet port H 2  is formed in the vicinity of the inlet port H 1  in the horizontal direction to improve the drying performance, a horizontal length of the return duct  114  communicating with the outlet port H 2  and the downstream end  1124 D of the second condensing duct  1124  can increase, and a distance between the downstream end  1124 D of the second condensing duct  1124  and the upstream end  114 U of the return duct  114  can increase. Therefore, a heater  350  having a sufficiently large size can be disposed inside or outside the return duct  114 , and the fan  130  can be disposed between the downstream end  1124 D of the second condensing duct  1124  and the upstream end  114 U of the return duct  114 . Therefore, the drying performance of the dishwasher  1  can be improved by the simple configuration, and the dishwasher  1  can have a compact structure having a small size. 
     As described above, the downstream end  1122 D of the first condensing duct  1122  can be positioned in the vicinity of the lower end of the rear portion of one sidewall  12 R of the tub  12 , and the upstream end  1124 U of the second condensing duct  1124  can be positioned in the vicinity of one side end of the rear portion of the bottom  12 B of the tub  12  ( FIGS.  3 ,  5 , and  7   ). For example, the downstream end  1122 D of the first condensing duct  1122  may be positioned adjacent to the rear lower portion R 13  of one sidewall  12 R of the tub  12  and the upstream end  1124 U of the second condensing duct  1124  may be positioned adjacent to the one rear side portion B 11  of bottom  12 B of the tub  12 . For example, the downstream end  1122 D of the first condensing duct  1122  may be positioned closest to rear lower portion R 13  among the nine regions R 11  to R 33  of one sidewall  12 R of the tub  12  ( FIG.  2  or  3   ), thereby being positioned in the vicinity of the lower end of the rear portion of one sidewall  12 R. And the upstream end  1124 U of the second condensing duct  1124  may be positioned closest to one rear side portion B 11  among the nine regions B 11  to B 33  of bottom  12 B of the tub  12  ( FIG.  2  or  3   ), thereby being positioned in the vicinity of one side end of the rear portion of bottom  12 B. Therefore, since both the downstream end  1122 D of the first condensing duct  1122  and the upstream end  1124 U of the second condensing duct  1124  are positioned at the rear side together with the inlet port H 1  and the outlet port H 2 , the condensing duct  112  can be formed in a shape similar to a straight line, and the length of the condensing duct  112  can decrease. Therefore, the flow resistance can be reduced, and the drying performance can be improved. 
     The second condensing duct  1124  can have a second water drain port D 2  ( FIG.  13   ). Therefore, the water introduced through the inlet port H 1  or the outlet port H 2  or the water condensed in the condensing duct  112  can be discharged to the outside through the second water drain port D 2 , thereby improving the drying performance of the drying device  100 . 
     In some examples, a second connection duct  1123  can be disposed between the first condensing duct  1122  and the second condensing duct  1124 . The second connection duct  1123  can communicate with the downstream end  1122 D of the first condensing duct  1122  and the upstream end  1124 U of the second condensing duct  1124  ( FIGS.  5  and  7   ). 
     As described above, the condensing duct  112  includes: the first condensing duct  1122  facing the outer surface of one sidewall  12 R of the tub  12  and having the upstream end communicating with the inlet port H 1 ; and the second condensing duct  1124  disposed lower than the bottom  12 B of the tub  12  and having the upstream end communicating with the downstream end of the first condensing duct  1122 . Therefore the condensing duct  112  adjoins the low-temperature air outside of one sidewall  12 R of the tub  12  and lower than the bottom  12 B of the tub  12  such that the moisture vapor contained in the air flowing along the condensing duct  112  is condensed into water and removed. Therefore, the drying performance can be improved by the simple structure and at low cost. 
     The upstream end  114 U of the return duct  114  can communicate with the downstream end  1124 D of the second condensing duct  1124 , and a downstream end  114 D of the return duct  114  can communicate with the outlet port H 2 . 
     For example, the downstream end  114 D of the return duct  114  can communicate with the distributor  150  that is inserted into the washing space  12 S through the outlet port H 2  and discharges the air into the washing space  12 S. 
     The second condensing duct  1124  and the return duct  114  can be positioned only under rear portions B 11 , B 12 , and B 13  of the bottom  12 B of the tub  12 . Therefore, since the second condensing duct  1124  and the return duct  114  are positioned at the rear side together with the outlet port H 2  and the inlet port H 1 , the second condensing duct  1124  and the return duct  114  can be formed in a shape similar to a straight line, and the lengths of the ducts  1124 , and  114  can decrease. Therefore, the flow resistance can be reduced, and the drying performance can be improved. In addition, the dishwasher  1  can have a compact structure having a small size. 
     The return duct  114  can be positioned between the bottom  12 B of the tub  12  and the second condensing duct  1124 . For example, at least a part of the return duct  114  can be disposed under the bottom  12 B of the tub  12 , and the part of the return duct  114  and the second condensing duct  1124  can be disposed vertically. 
     That is, at least a part of the return duct  114  can be disposed higher than the second condensing duct  1124 . 
     Therefore, it can be possible to help to prevent the water introduced into the second condensing duct  1124  through the inlet port H 1  and the water condensed in the condensing duct  112  from being introduced into the return duct  114 . Therefore, it can be possible to help to prevent the water in the condensing duct  112  from being introduced into the washing space  12 S through the outlet port H 2  communicating with the return duct  114 , thereby improving the drying performance. That is, the drying performance can be improved by reducing or preventing the water from flowing reversely. 
     The return duct  114  and the second condensing duct  1124  can at least partially adjoin each other in the longitudinal direction of the return duct  114  and the second condensing duct  1124 . At the portion where the return duct  114  and the second condensing duct  1124  adjoin each other, the return duct  114  and the second condensing duct  1124  can be separated by a separation wall W disposed in the longitudinal direction of the return duct  114  and the second condensing duct  1124  ( FIGS.  12  to  15   ). 
     Therefore, the return duct  114  and the second condensing duct  1124  can be easily manufactured by the simple configuration and at low cost. In addition, since the return duct  114  and the second condensing duct  1124  are separated by the single separation wall W, a part of heat generated from the heater  140  disposed in the return duct  114  can be easily transferred to the second condensing duct  1124 . Therefore, a small amount of water in the second condensing duct  1124  is vaporized by the heat transferred to the second condensing duct  1124 , and thus the humidity in the second condensing duct  1124  decreases, which makes it possible to reduce or prevent the proliferation of bacteria or mold in the second condensing duct  1124 . 
     The return duct  114  can have a third water drain port D 3  ( FIG.  13   ). Therefore, the water introduced through the outlet port H 2  and the water condensed in the return duct  114  can be discharged to the outside of the return duct  114  through the third water drain port D 3 , thereby improving the drying performance of the drying device  100 . In this case, the outside of the return duct  114  can be the inside of the second condensing duct  1124  ( FIG.  13   ). 
     The fan  130  can be disposed between the downstream end  1124 D of the condensing duct  112  and the downstream end  114 D of the return duct  114 . For example, the fan  130  can be disposed between the second condensing duct  1124  and the return duct  114 . 
     Therefore, the fan  130  can help to prevent the occurrence of vortex and allow the air to smoothly flow in a downstream portion (e.g., between the condensing duct and the return duct) of the drying duct  110  where the flow direction of the air is considerably changed. Therefore, flow resistance is not increased, which makes it possible to improve the drying performance of the drying device  100 . 
     The fan  130  can communicate with the second condensing duct  1124  ( FIG.  15   ). For example, the fan  130  can communicate downwardly with the downstream end  1124 D of the second condensing duct  1124 . 
     In addition, the fan  130  can communicate with the return duct  114  ( FIG.  15   ). For example, the fan  130  can communicate laterally with the upstream end  114 U of the return duct  114 . 
     The fan  130  can be disposed higher than the downstream end  1124 D of the second condensing duct  1124  ( FIG.  15   ). 
     Therefore, it can be possible to help to prevent a motor  136  of the fan  130  from coming into contact with the water introduced into the condensing duct  112  or the water condensed in the condensing duct  112 . Therefore, it can be possible to help to prevent the water from being introduced into the motor  136  of the fan  130  and thus help to prevent the fan  130  from being broken down, thereby improving the durability and stability of the drying device  100 . 
     The fan  130  can allow the air to flow in the drying duct  110 . Specifically, for example, the fan  130  can introduce the air in the first condensing duct  1122  into the second condensing duct  1124 . In addition, the fan  130  can introduce the air in the second condensing duct  1124  into the return duct  114 . In addition, the fan  130  can discharge the air in the return duct  114  into the washing space  12 S through the outlet port H 2  and the distributor  150  to be described below. 
     The fan  130  can include a fan blade  132 , a fan housing  134 , and the motor  136 . 
     The fan blade  132  can be fixedly coupled to a rotary shaft  138  and rotated by the motor  136 . The fan blade  132  can be accommodated in the fan housing  134 . 
     The fan housing  134  can communicate with the downstream end  1124 D of the second condensing duct  1124  and the upstream end  114 U of the return duct  114 . 
     For example, the fan housing  134  can have a through-hole formed in a lower surface thereof and communicate downwardly with the downstream end  1124 D of the second condensing duct  1124  ( FIG.  15   ). In addition, the fan housing  134  can have a through-hole formed in a lateral surface thereof and communicate laterally with the upstream end  114 U of the return duct  114  ( FIG.  15   ). 
     The fan housing  134  can include an upper wall  134 T. The upper wall  134 T can be disposed between the fan blade  132  and the motor  136  disposed above the fan blade  132 . 
     Therefore, even though the fan blade  132  comes into contact with the water introduced into the return duct  114  through the outlet port H 2 , the water being in contact with the fan blade  132  is blocked by the upper wall  134 T, such that the water cannot come into contact with the motor  136 . Therefore, it can be possible to help to prevent the water from being introduced into the motor  136  and thus help to prevent the fan  130  from being broken down, thereby improving the durability and stability of the drying device  100 . 
     The upper wall  134 T can have a hole penetrated by the rotary shaft  138 . 
     The motor  136  can be coupled to the fan blade  132  by means of the rotary shaft  138 . The motor  136  can rotate the fan blade  132 . 
     The motor  136  can be disposed above the fan blade  132 . In addition, the motor  136  can be disposed on the upper wall  134 T. 
     The rotary shaft  138  of the fan  130  can extend in an approximately vertical direction. 
     Therefore, the fan  130  can be installed to be laid between the second condensing duct  1124  and the return duct  114 . Therefore, the fan  130  having a sufficiently large size can be installed even though the installation space or the installation position is restricted. Therefore, the drying performance of the dishwasher  1  can be improved by the simple configuration and at low cost, and the dishwasher  1  can have a compact structure having a small size. In this case, the fan  130  can be a centrifugal fan. In addition, since the motor  136  can be disposed above the fan blade  132 , it can be possible to help to prevent the water from being introduced into the motor  136 . 
     The heater  140  can be disposed between the downstream end  1124 D of the condensing duct  112  and the downstream end  114 D of the return duct  114 . For example, the heater  140  can be disposed in the return duct  114 . 
     Therefore, the heater  140  can heat the air in the downstream portion (e.g., the return duct) of the drying duct  110  close to the outlet port H 2  and discharge the high-temperature dry air into the washing space  12 S, thereby improving the drying performance by the simple configuration and at low cost. 
     The heater  140  can be disposed in the return duct  114  ( FIGS.  10  to  15   ). However, the present disclosure is not limited to this configuration. For example, unlike the drawings, the heater  140  can be provided adjacent to the return duct  114  and disposed outside the return duct  114 . 
     Since the heater  140  is disposed in the return duct  114  as described above, the air can be effectively heated in the return duct  114  close to the outlet port H 2 . Therefore, the heated air flowing into the washing space  12 S can effectively remove moisture remaining on dishes in the washing space  12 S. Therefore, the drying performance can be improved by the simple structure and at low cost. 
     In addition, since the heater  140  is disposed in the return duct  114 , the heater  140  is positioned to be distant from the water introduced into the condensing duct  112  or the water condensed in the condensing duct  112  without coming into contact with the water. Therefore, it can be possible to help to prevent the heat generated by the heater  140  from vaporizing a large amount of water collected in the condensing duct  112 . Therefore, the high-temperature dry air in the return duct  114  can flow into the washing space  12 S, thereby improving the drying performance. 
     The heater  140  can heat the air in the drying duct  110 . 
     As described above, the drying device  100  includes the drying duct  110 , the fan  130 , and the heater  140 , and the drying duct  110  is disposed outside the tub  12  and includes the condensing duct  112  and the return duct  114 , which makes it possible to improve the drying performance by the simple configuration and at low cost. 
     As illustrated in  FIG.  14   , the distributor  150  can include an insertion part  152  and a lid  154 . 
     A lower end of the insertion part  152  can communicate with the downstream end  114 D of the return duct  114 , and an upper end of the insertion part  152  can be coupled to the lid  154 . The insertion part  152  can be installed to penetrate the outlet port H 2  formed in the bottom  12 B of the tub  12 . 
     The air heated in the return duct  114  can flow into the washing space  12 S through the insertion part  152 . 
     The lid  154  can be installed at an upper end of the insertion part  152  and disposed in the washing space  12 S. 
     The lid  154  can block the water in the washing space  12 S from being introduced into the insertion part  152  and the return duct  114 . 
     In addition, the lid  154  can prevent the air flowing out of the insertion part  152  from flowing upward in the vertical direction when the air is introduced into the washing space  12 S. Therefore, since the condition i) is provided, the dry air introduced into the washing space  12 S through the outlet port H 2  can effectively circulate everywhere in the washing space  12 S until the dry air is introduced into the drying device  100  through the inlet port H 1 , thereby improving the drying efficiency. 
     In some examples, the second downstream duct  1124 B, the fan housing  134 , and the return duct  114  illustrated in  FIGS.  11  to  13    can include a first housing C 1 , a second housing C 2 , a third housing C 3 , and a fourth housing C 4 , as illustrated in  FIG.  14   . 
     The first housing C 1  can be disposed at the lower side and opened upward. 
     The second housing C 2  can be disposed on the first housing C 1  and coupled to the first housing C 1 . 
     The third housing C 3  can be opened downward, disposed on the second housing C 2 , and coupled to the second housing C 2 . 
     The fourth housing C 4  can be disposed on one end of the second housing C 2  and coupled to the second housing C 2 . 
     The second downstream duct  1124 B can be defined by the first housing C 1  and the second housing C 2 , and the return duct  114  can be defined by the second housing C 2  and the third housing C 3 . The separation wall W can be the bottom of the second housing C 2 . 
     The fan housing  134  can be defined by one end of the second housing C 2  and the fourth housing C 4 . That is, a part of the fan housing  134  (one end of the second housing) can be integrated with a part of the return duct  114  (the remaining part of the second housing). The fourth housing C 4  can be the upper wall  134 T of the fan housing  134 . 
     The second water drain port D 2  can be formed in the bottom of the first housing C 1 , and the third water drain port D 3  can be formed in the bottom of the second housing C 2 . 
     The heater  140  can be disposed in the internal space defined by coupling the second housing C 2  and the third housing C 3 . In this case, a fixing part  142 , which has high heat resistance and low thermal conductivity, can be fixed to the second housing C 2  or the third housing C 3 , and the heater  140  can be installed by being coupled to the fixing part  142 . Therefore, it can be possible to help to prevent the second housing C 2  or the third housing C 3  from being damaged by the heater  140 . 
     As described above, the second downstream duct  1124 B, the fan housing  134 , and the return duct  114  can be configured by coupling the first housing C 1 , the second housing C 2 , the third housing C 3 , and the fourth housing C 4 . Therefore, the drying device  100  can be simply and easily manufactured and easily maintained. Further, the drying device  100  can have a compact structure having a small size. 
     In some examples, for convenience, the configuration has been described in which the drying duct  110  is divided into the condensing duct  112  and the return duct  114 . However, the condensing duct  112  and the return duct  114  can be integrated. 
     In some examples, the first condensing duct  1122  and the second condensing duct  1124  can also be integrated. 
     In some implementations, the ducts  110 ,  112 ,  1122 ,  1124 , and  114  can each be made of a metallic material such as aluminum or stainless steel. In some examples, the ducts  110 ,  112 ,  1122 ,  1124 , and  114  can be manufactured by steel metal working or injection molding. 
     In some examples, some components of the drying device  100 , such as the fan  130 , can be made of plastic. 
     While the present disclosure has been described above with reference to the accompanying drawings, the present disclosure is not limited to the drawings and the implementations disclosed in the present specification, and it is apparent that the present disclosure can be variously changed by those skilled in the art without departing from the technical spirit of the present disclosure. Further, even though the operational effects of the configurations of the present disclosure have not been explicitly disclosed and described in the description of the implementations of the present disclosure, the effects, which can be expected by the corresponding configurations, should be acceptable.