Patent Publication Number: US-2010107703-A1

Title: Drum-type washer/dryer

Description:
TECHNICAL FIELD 
     The present invention relates to a drum-type washer/dryer provided with a heat pump for drying laundry. 
     BACKGROUND ART 
     A washer/dryer provided with a heat pump for drying laundry is notable for its high dry capability and effective energy saving. In such a washer/dryer, the evaporator condenses and collects vapor emitted from laundry during the laundry dry operation. The compressor compresses the refrigerant, which has collected latent heat during vapor condensation, to elevate the temperature of the refrigerant. The condenser heats the air used in the dry operation with the refrigerant of elevated temperature. The use of latent heat obtained during vapor condensation as source of energy for heating the air used in the dry operation does indeed cause slight exterior heat loss (energy loss); however, most of the energy can be reused without loss. Therefore, efficient dry operation can be realized. 
     The drum-type washer/dryer having a heat pump is provided with a laterally disposed cylindrical water tub. The water tub has a warm air inlet and a warm air outlet provided in separate axial locations of the water tub. A drum is disposed inside the water tub. Also, a drive unit for rotating the drum and an airflow duct communicating the warm air outlet and the warm air inlet are provided outside the water tub. An evaporator and a condenser constituting the heat pump are disposed in the airflow duct. The evaporator and the condenser connected to the compressor placed outside the airflow duct. Further, a blower for re-circulating the air inside the water tub through the airflow duct is provided outside the airflow duct. 
     When drying laundry, the compressor of the heat pump is activated while the drum is rotated by the drive unit and the air inside the water tub is re-circulated through the airflow duct by the blower. Thus, vapor contained in the air supplied to the airflow duct from the water tub is cooled and dehumidified by heat exchange carried out by the evaporator. The dehumidified air is heated by heat exchange carried out by the condenser and subsequently supplied into the water tub as warm air. As a result, dry warm air is repeatedly supplied into the drum, whereby laundry is dried. 
     The drum-type washer/dryer provided with a heat pump described in JP 2005-52533 A has the warm air inlet and the warm air outlet of the water tub provided in separate axial locations of the water tub. As opposed to this, the airflow duct is disposed below the water tub so as to be perpendicular to the axial direction of the water tub. Further, the compressor of the heat pump is disposed below the water tub and spaced away from the airflow duct in the axial direction of the water tub by a predetermined distance. 
     DISCLOSURE OF THE INVENTION 
     Problem to be Overcome by the Invention  
     In the washer/dryer described in the above publication, since the direction in which the warm air inlet and the warm air outlet are provided and the direction in which the airflow duct is disposed are perpendicular to each other, the re-circulation passageway for re-circulating the air inside the water tub needs to make a large curve especially in the range running from the water tub to the airflow duct. Consequently, the configuration of the re-circulation air passageway as a whole becomes complex. Thus, conduit resistance inside the re-circulation air passageway is increased, resulting in less amount of re-circulation flow. Consequently, heat exchange efficiency at the evaporator and the condenser of the heat pump is reduced, leading to poor dry performance. 
     Further, the space below the water tub is limited by the height of the water tub itself and the suspension supporting the water tub. Thus, in order to install the airflow duct and the compressor, which is generally tall, in the manner described in the washer/dryer of the above mentioned publication, the space below the water tub needs to be increased, which created drawback of size and weight increase of the washer/dryer as a whole. 
     Object of the present invention is to provide a drum-type washer/dryer with high dry performance and compact and light-weight overall configuration. 
     Means to Overcome the Problem  
     A drum-type washer/dryer of the present invention is characterized by a laterally disposed cylindrical water tub having a warm air inlet and a warm air outlet; a drum disposed inside the water tub; a drive unit that rotates the drum; an airflow duct communicating the warm air outlet and the warm air inlet of the water tub; a heat pump including an evaporator and a condenser disposed in the airflow duct and a compressor to which the evaporator and the condenser communicate; a blower that re-circulates air inside the water tub through the airflow duct, the warm air inlet and the warm air outlet of the water tub being provided in separate locations in an axial direction of the water tub, the airflow duct being disposed substantially immediately below the water tub and along the axial direction of the water tub, and the compressor of the heat pump being disposed perpendicular to the axial direction of the water tub and laterally of the airflow duct. 
     EFFECT OF THE INVENTION 
     According to the drum-type washer/dryer of the present invention, the re-circulation air passageway for re-circulating air in the water tub need not be curved especially in the range running from the water tub to the airflow duct but can be provided substantially linear instead. This also allows simple overall configuration of the re-circulation air passageway. Thus, there is no increase in conduit resistance inside the re-circulation air passageway, which in turn increases the amount of available re-circulation airflow, thereby improving the heat exchange efficiency at the evaporator and the condenser of the heat pump to obtain high dry performance. 
     Further, the airflow duct and the compressor of the heat pump can be installed space-efficiently in the limited space below the water tub, allowing more compact and light-weight overall configuration of the drum-type washer/dryer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view illustrating one exemplary embodiment of the present invention and shows an interior configuration of a drum-type washer/dryer; 
         FIG. 2  is a broken cross-sectional side view of the drum-type washer/dryer in its entirety; 
         FIG. 3  is vertical cross-sectional side view of an airflow duct and its periphery; 
         FIG. 4  is an exploded perspective view of the airflow duct; 
         FIG. 5  is a front view of the compressor and its periphery; 
         FIG. 6  illustrates an overall configuration of a heat pump; 
         FIG. 7  is a perspective view of the airflow duct and its periphery; 
         FIG. 8  is a broken perspective view of a filter; 
         FIG. 9  is a vertical cross-sectional front view of the airflow duct; and 
         FIG. 10  is a perspective view of a drain valve and its periphery. 
     
    
    
     THE BEST MODE FOR CARRYING OUT THE INVENTION 
     A detailed description will be given on the present invention with reference to the accompanying drawings. 
       FIGS. 1 to 10  illustrate one exemplary embodiment of the present invention. 
       FIG. 2  illustrates the overall configuration of the drum-type washer/dryer. A cylindrical water tub  2  is supported by a pair of left and right suspensions  3  (refer to  FIG. 1 ) inside a cabinet  1  constituting the exterior housing of the drum-type washer/dryer. The water tub  2  is laterally disposed with its axis running in the longitudinal direction (left and right direction in  FIG. 2 ) and being slightly inclined upward (inclined leftwardly upward in  FIG. 2 ). Also, an annular water tub cover  4  having an opening  5  in its substantial center is mounted on the front end of the water tub  2 . An opening  6  is provided on the front surface of the cabinet  1  for loading and unloading of laundry. The opening  5  of the water tub cover  4  communicates with the opening  6  by bellows  7 . An openable/closable door is provided at the front side of the opening  6 . 
     A warm air outlet  9  is provided above the upper front-end side of the water tub  2 . A warm air inlet  10 , on the other hand, is provided above the rear-end side of the water tub  2 . In other words, the warm air outlet  9  and the warm air inlet  10  are provided on separate axial locations of the water tub  2 . A drain outlet  11  is provided at the rear-end bottom of the water tub  2 . A drain pipe  12  communicates with the drain outlet  11 . 
     A cylindrical drum  13  is disposed inside the water tub  2 . A plurality of perforations  14  are provided substantially throughout (though only a portion is illustrated in  FIG. 2 ) the periphery (waist) of the drum  13 . The perforations  14  function as water perforations as well as air perforations. Further, a warm air intake  15  composed of a plurality of small perforations is provided in the central periphery of the rear surface of drum  13 . Further, a reinforcing element  16  is mounted on the back side of the drum  13  rear surface. A shaft  17  is mounted on the rear surface center of the drum  13  via the reinforcing element  16 . 
     A bearing housing  18  is mounted on the rear surface center of the water tub  2 . The shaft  17  is passed through the bearing housing  18  via bearings  19  and  20 . Thus, as is the case with the water tub  2 , the drum  13  is supported laterally with its axis running in the longitudinal direction (left and right direction in  FIG. 2 ) and being upwardly inclined (inclined leftwardly upward in  FIG. 2 ). 
     A stator  22  constituting a motor  21  is secured on the outer periphery of the bearing housing  18 . A rotor  23  constituting the motor  21 , on the other hand, is mounted on the rear end of the shaft  17 . The rotor  23 , in this case, opposes the stator  22  from the outside. That is, the motor  21  is a brushless DC motor of an outer-rotor type and functions as the drive unit for rotating the drum  13  about the shaft  17 . 
     A warm air cover  24  having an opening  25  in its substantial center is provided in the rear surface interior of the water tub  2 . The opening  25  of the warm air cover  24  is disposed so as to surround the shaft  17 . The portion of the warm air cover  24  above the opening  25  covers the warm air inlet  10  so as to be in confrontation with the warm air inlet  10 . Also, almost the entire portion of the warm air cover  24  has a predetermined spacing (approximately ⅓ of the spacing between the rear end surface of the drum  13  and the rear surface of the water tub  2 , for example) from the rear surface of the water tub  2 . Thus, space is created between the rear surface of the drum  13  and the rear surface of the water tub  2  by being divided off by the warm air cover  24 . The space between the rear surface of the water tub  2  and the warm air cover  24  functions as a warm air conduit  26  communicating from the warm air inlet  10  to the opening  25  (space around the shaft  17 ). The opening  25  of the warm air cover  24  has a diameter sufficiently larger than the diameter of the shaft  17  so as to function as an outlet of the warm air conduit  26 . 
     A plurality of large perforations  27  are provided in the reinforcing element  16 , more specifically, in the peripheral portions of the shaft  17 . The perforations  27  provide communication between the opening  25  of the warm air cover  24  and the warm air intake  15  of the drum  13  to constitute a warm air intake  28 . 
     Also, a sealing element  29  is attached on the outer periphery of the portion of the reinforcing element  16  where the warm air intake  28  is formed. The sealing element  29  being composed of an elastic material such as synthesized rubber is in abutment with the peripheral portions of the opening  25  of the warm air cover  24  and is placed in sliding contact with the peripheral portion of the opening  25  of the warm air cover  24  by the rotation of the drum  13 . Consequently, the sealing element  29  provides a seal between the drum  13  and the water tub  2 , more specifically, between the warm air intake  28  and the warm air conduit  26 . 
     The bottom of the cabinet  1  is constituted by the platform  30 . The airflow duct  32  is disposed on the platform  30  via a plurality of anti-vibration rubbers  31 . The airflow duct  32  is secured to the platform  30  by a plurality of bolts  33  penetrating each anti-vibration rubber  31  and a plurality of nuts  34  capable of screw engagement with the protruding distal ends of each bolt  33 . Also, the airflow duct  32  is disposed substantially immediately below the water tub  2  and along the axial direction of the water tub  2  as shown in  FIG. 2 . 
     The airflow duct  32  is configured by a bottom plate  35 , sidewalls  36  and  37  placed on the left and right portions of the bottom plate  35 , a front wall  38  attached to the front ends of the sidewalls  36  and  37  and the front end of the bottom plate  35 , a rear wall  39  attached to the rear ends of the sidewalls  36  and  37  and the rear end of the bottom plate  35 , and the upper cover  40  attached on the upper ends of the sidewalls  36  and  37  and the upper end of the front wall  38  and the upper end of the rear wall  39  as shown in  FIG. 4 . The airflow duct  32  is formed as an air passageway in a substantially rectangular cylindrical form surrounded by the bottom wall  35 , the sidewalls  36  and  37 , and the front wall  38  and the rear wall  39 . 
     An evaporator  41  and a condenser  42  are disposed between the front wall  38  and the rear wall  39  of the airflow duct  32 . In the present exemplary embodiment, the evaporator  41  is disposed in the front wall  38  side and the condenser is formed in the rear wall  39  side. 
     The sidewall  36  constituting the left side of the airflow duct  32  is made of a single sheet of a plate-form element and externally covers the end plate  43  constituting the left end of the evaporator  41  and the endplate  44  constituting the left end of the condenser  42 . The sidewall  37  constituting the right side of the airflow duct  32  comprises the end plate  45  constituting the right end of the evaporator  41 , the end plate  46  constituting the right end of the condenser  42  and an auxiliary plate  47  connecting the end plate  45  and the end plate  46 . 
     Thus, a portion (inlet  48   a , outlet  48   b , and the curvature  48   c ) of the refrigerant pipe  48  constituting the evaporator  41  outwardly protrudes from the sidewall  37  of the airflow duct  32 . Also, a portion (inlet  49   a , outlet  49   b , and the curvature  49   c ) of the refrigerant pipe  49  constituting the condenser  42  outwardly protrudes from the sidewall  37  of the airflow duct  32 . A plurality of curvatures  48   c  of the refrigerant pipe  48  is provided between the inlet  48   a  and the outlet  48   b , and the curvatures  49 c of the refrigerant pipe  49  are provided between the inlet  49   a  and the outlet  49   b.    
     As opposed to this, the curvatures (refer to  FIG. 9 ) of the refrigerant pipe  48  protruding from the end plate  43  of the evaporator  41  are covered by the sidewall  36  of the airflow duct  32  so as not to outwardly protrude from the airflow duct  32 . Also, the curvatures (refer to  FIG. 9 ) of the refrigerant pipe  49  protruding from the end plate  44  of the condenser  42  is covered by the sidewall  36  of the airflow duct  32  so as not to outwardly protrude from the airflow duct  32 . 
     A plurality of heat exchange fins  50  is disposed in parallel between the end plate  43  and the end plate  45  of the evaporator  41 , and a plurality of straight portion (not shown) of the refrigerant pipe  48  is disposed in the plurality of heat exchange fins  50 . Also, a plurality of fins  51  are disposed in parallel between the end plate  44  and the end plate  46  of the condenser  42  and a plurality of straight portion (not shown) of the refrigerant pipe  49  is disposed in the heat exchange fins  51 . The straight portions of the refrigerant pipe  48  are connected by the curvature  48   c  respectively and the straight portions of the refrigerant pipes  49  are connected by the curvatures  49   c  respectively. 
     The bottom plate  35  of the airflow duct  32  includes a compressor placement  52  extending to the right side of the evaporator  41 . The compressor  53  is disposed on the compressor placement  52  as illustrated in  FIGS. 1 and 2 . Thus, the compressor  53  is disposed in a lateral direction of the airflow duct  32 , the lateral direction being perpendicular to the axial direction of the water tub  2 . In this case, the bottom plate  35  functions as the common bottom plate  35  of the airflow duct  32  and the compressor  53 . 
     The compressor  53 , as illustrated in  FIG. 5 , is disposed on the bottom plate  35  (compressor placement  52 ) via a reinforcing plate  54  made of metal such as a steel plate. Also, the compressor  53  is provided with a reservoir  56  for liquid refrigerant.  FIGS. 1 ,  2  and  5  illustrate the compressor  53  with the noise reduction cover  55  (refer to  FIG. 7 ) removed. The bottom plate  35  of the airflow duct  32  is made of plastic. 
     Referring to  FIG. 6 , the above described evaporator  41 , the condenser  42 , the compressor  53  and a capillary tube  59  together constitute the heat pump  57  (refrigerating cycle). The evaporator  41 , the condenser  42 , the compressor  53  and the capillary tube  59  of the heat pump  57  are connected cyclically by a connection pipe  58 . When the compressor  53  is activated, the refrigerant is circulated in sequence from the compressor  53 , the condenser  42 , the capillary tube  59 , and the evaporator  41 . 
     As illustrated in  FIG. 4 , an entrance  60  is provided in the form of a rectangular opening in the front wall  38  of the airflow duct  32 . Also, the exit  61  is provided in the form of a circular opening in the rear wall  39  of the airflow duct  32 . The entrance  60  and the exit  61  are provided so as to oppose each other and the center of the entrance  60  and the center of the exit  61  are arranged to substantially match when viewed from the front. Also, the evaporator  41  and the condenser  42  of the heat pump  57  are disposed between the entrance  60  and the exit  61  so that their centers substantially match with the center of the entrance  60  and the center of the exit  61  when viewed from the front. 
     The upper cover  40  of the airflow duct  32  is divisible to the evaporator side upper cover  62  and the condenser side upper cover  63 . The evaporator side upper cover  62  is detachably attached to the front-side (evaporator  41  side) upper end of the sidewalls  36  and  37  and the upper end of the front wall  38  of the airflow duct  32 . The condenser side upper cover  63  is detachably attached to the rear-side (condenser  42  side) upper end of the sidewalls  36  and  37  and the upper end of the rear wall  39  of the airflow duct  32 . Removal of the evaporator side upper cover  62  allows maintenance of evaporator  41  and removal of the condenser side upper cover  63  allows maintenance of the condenser  42 . 
     AS illustrated in  FIGS. 2 ,  3  and  7 , a filter case  64  is attached to the entrance  60  of the airflow duct  32 . The filter case  64  is installed so as to be aligned in a longitudinally-oriented row with the evaporator  41  and the condenser  42  of the heat pump  57  and on the upwind of the airflow duct  32 . 
     As illustrated in  FIG. 7 , a rectangular opening  65  is provided in the front end side of the filter case  64 . The rear end side of the filter case  64  is also provided with a rectangular opening (not shown). The rear-end opening is substantially of the same size as the entrance  60  of the airflow duct  32 , and communicates with the entrance  60 . As opposed to this, the front-end opening  65  is shorter in vertical length as compared to the rear-end opening. Also, the front-end opening  65  has higher elevation compared to the rear-end opening of the filter case  64 . An upwardly protruding connection port  66  is provided in the upper front end side of the filter case  64 . 
     The filter case  64  contains a filter  67 . The filter  67  collects lint discharged from laundry during the dry operation, and can be moved in and out of the filter case  64  from the above-described front-end opening  65 . As illustrated in  FIG. 8 , a plurality of filter bodies  68  having varying mesh sizes are stacked on a filter frame  69  of the filter  67 . Respective mesh size of the filter bodies  68  are arranged to be coarser in the upper stack (later described upwind of the re-circulation air passageway  90 ) of the filter frame  69  and finer in the lower stack (downwind of the re-circulation air passageway  90 ). 
     As illustrated in  FIG. 9 , a drain receptacle  70  is provided immediately below the evaporator  41 . The drain receptacle  70  is downwardly sloped toward the drainage  71  provided in the right end side. A drain reservoir  73  is provided below the drain receptacle  70  and the connection port  74  of the drain reservoir  73  is connected to the above described drainage  71  via a connection pipe  72 . The drain reservoir  73  may be made of plastic for example in which case may be molded integrally with the bottom plate  35  of the airflow duct  32 . 
     Also, the drain reservoir  73  in its entirety exhibits a flat container form and its bottom  73   a  is downwardly sloped toward the right end side (connection port  74  side). The above described connection port  74  is provided immediately above the lowermost portion (the lowermost portion of the drain reservoir  73 ). On the other hand, a drain pump  75  is disposed on the platform  30  and the suction port of the drain pump  75  communicates with the proximity of the lowermost portion of the drain reservoir  73  described above. Water accumulated in the drain reservoir  73  is sucked out by the drain pump  75  from the lowermost portion of the drain reservoir  73 . 
     A drain valve  76  (refer to  FIG. 10 ) is disposed on the platform  30  and in the left side of the airflow duct  32 . An inlet  76   a  of the drain valve  76  is connected to the drain pipe  12  (refer to  FIGS. 1 and 2 ) via the drain filter case  77  and waste water drained from the water tub  2  passes through the drain filter case  77  through the drain pipe  12 . A drain filter (not shown) can be placed in the drain filter case  77  which drain filter collects the lint in the waste water passing through the drain filter case  77 . 
     On the other hand, an outlet  76   b  of the drain valve  76  is connected to the drain hose  79  via the drain joint  78 . The distal end (not shown) of the drain hose  79  is guided out of the drum-type washer/dryer. A connection hose  81  is connected to the drain joint  78  via the drain valve  80 . The connection hose  81  is connected to the exhaust of the above described drain pump  75 . That is, the exhaust of the drain pump  75  is connected to the drain conduit extending from the water tub  2  to the drain hose  79 , more specifically in the portion downstream of the drain valve  76 . 
     A check valve  80  allows water flow from the connection hose  81  (drain pump  75 ) to the drain hose  79  but prevents water flow in the reverse direction (water flow from drain valve  76  to the connection hose  81 ). Thus, waste water from the water tub  2  can be prevented from reaching into the airflow duct  32  through the connection hose  81  and the drain pump  75 . Also, lint that could not be collected by the drain filter can be prevented from reaching into the airflow duct  32  from the water tub  2  with waste water. Thus, clogging of airflow duct  32  (especially between the plurality of heat exchange fins  50  of the evaporator  41  and between the plurality of heat exchange fins  51  of the condenser  42 ) by lint uncollected by the drain filter can be prevented. 
     As illustrated in  FIGS. 2 ,  3  and  7 , the lower end of a connection hose  82  in accordion shape is connected to the connection port  66  of the filter case  64 . The above described water tub cover  4  is hollow substantially throughout its entire circumference to form a re-circulation flow duct  83  communicating with the warm air outlet  9 . That is, the re-circulation flow duct  83  is formed by utilizing the wall of the water tub cover  4 . The connection port  84  is provided in the lower portion of the re-circulation duct  83 , and the upper end of the above described connection hose  82  is connected to the connection port  84 . The re-circulation duct  83  may be formed by making the left half circumference and the right half circumference of the water tub cover  4  hollow. 
     On the other hand, an inlet (not shown) formed in the casing  86  of the blower  85  communicates with the exit  61  of the airflow duct  32 . An impeller (not shown) rotatably driven by a (motor not shown) is contained inside the casing  86 . The blower  85  sucks air from the inlet of the above described casing  86  by rotating the impeller and exhausts from the outlet  87 . 
     As illustrated in  FIG. 2 , the outlet  87  of the casing  86  communicates with the warm air inlet  10  of the water tub  2  via the accordion connection hose  88  and the air supply duct  89 . The air supply duct  89  is disposed along the circumference of the motor  21  so as to circumvent the motor  21 . 
     As described above, the entrance  60  of the airflow duct  32  communicates with the warm air outlet  9  of the water tub  2  via the filter case  64 , the connection hose  82  and the air re-circulation duct  83 . Also, the exit  61  of the airflow duct  32  communicates with the warm air inlet  10  of the water tub  2  via the blower  85 , the connection hose  88  and the air supply duct  89 . Such configuration provides the re-circulation air passageway  90  that connects the warm air outlet  9  and the warm air inlet  10  of the water tub  2 . 
     Next, a description will be given on the operation of the above described configuration. 
     When a standard operation course is started, the drum-type washer/dryer initially executes the wash step (wash and rinse operation). In the wash step, the drum-type washer/dryer supplies water to the water tub  2  by a water supplier not shown and subsequently activates the motor  21  to alternately rotate the drum  13  in the forward and reverse directions at low speed. 
     When the wash step is completed, the drum-type washer/dryer executes the dehydration step. In the dehydration step, the drum-type washer/dryer rotates the drum  13  in a single direction at high speed after draining the water inside the water tub  2 . Thus, the laundry inside the drum  13  is centrifugally dehydrated. 
     When the dehydration step is completed, the drum-type washer/dryer executes the dry step. In the dry step, the drum-type washer/dryer rotates the drum  13  in the forward and reverse directions at low speed as well as rotating the impeller by activating the blower  85 . The rotation of the impeller supplies the air inside the water tub  2  into the airflow duct  32  via the hot air outlet  9 , the re-circulation duct  83 , the connection hose  82 , and the filter case  64 . 
     At this instance, the drum-type washer/dryer activates the compressor  53  of the heat pump  57 . The activation of the compressor  53  compresses the refrigerant sealed in the heat pump  57  to increase its temperature and pressure whereafter the refrigerant is flow into the condenser  42 . The refrigerant of high temperature and high pressure flown into the condenser  42  is condensed in the condenser  42 , at which point the refrigerant is heat exchanged with the air in the airflow duct  32 . Consequently, the air inside the airflow duct  32  is heated, whereas the temperature of the refrigerant is lowered and the refrigerant is liquidated. The liquidated refrigerant is depressurized when passing through the capillary tube  59  and thereafter flown into the evaporator  41 . The refrigerant flown into the evaporator  41  is evaporated in the evaporator  41  at which point heat exchange is carried out with the air in the airflow duct  32 . Consequently, the air in the airflow duct  32  is cooled whereas the refrigerant which has taken heat away from the air in the airflow duct  32  is resent to the compressor  53  in such state. 
     Under such configuration, the air flown into the airflow duct  32  from the water tub  2  is cooled and dehumidified by the evaporator  41  and thereafter heated into warm air by the condenser  42 . Then, the warm air is supplied into the water tub  2  from the warm air inlet  10  via the connection hose  88  and the air supply duct  89 . 
     The warm air supplied into the drum  13  takes away moisture from the laundry and thereafter flown into the airflow duct  32  again from the warm air outlet  9  via the re-circulation duct  83  and the connection hose  82 . 
     Thus, the laundry inside the drum  13  is dried by re-circulating air between the airflow duct  32  including the evaporator  41  and the condenser  42  and the drum  13 . 
     In the dry step, the lint discharged from the laundry inside the drum  13  is carried into the filter case  64  via the re-circulation duct  83  and the connection hose  82  by air flowing out of the above described warm air outlet  9 . The lint is collected in the filter case  64  by the filter  67 . The collected lint is can be removed from the filter  67  by removing the filter  67  from the filter case  64  after completing the operation. Lint discharged from laundry can be collected again by putting the lint-free filter  67  back into the lint filter  64 . 
     As described above, in the dry step, the evaporator  41  cools and dehumidifies the air passing through the airflow duct  32 . At the same time, moisture contained in the air is condescended on the surface of the evaporator  41  and the condescended dew drips into the drain receptacle  70  located immediately below the evaporator  41 . The condescended dew dripped on to the drain receptacle  70  flows down along the slope of the drain receptacle  70  and discharged into the drain reservoir  73  from the drain outlet  71  via the connection pipe  72 . 
     Since the bottom  73   a  of the drain reservoir  73  is sloped, the condescended dew is gradually accumulated into the drain reservoir  73  from the lowermost side of the drain reservoir  73 . Then upon activation of the drain pump  75 , the condescended dew accumulated in the drain reservoir  73  is effectively sucked out by the drain pump  75  from the lowermost portion of the drain reservoir  73 . The condescended dew sucked by the drain pump  75  is discharged from the drum-type washer/dryer from the connection hose  81  via the drain joint  78  and the drain hose  79 . When the dry step is completed, the drum-type washer/dryer completes the series of standard operation course. 
     Thus, according to the present exemplary embodiment, the warm air inlet  10  and the warm air outlet  9  are provided in separate axial locations in the axial direction of the cylindrical water tub  2  and the airflow duct  32  that communicates the warm air inlet  10  and the warm air outlet  9  is disposed substantially immediately below the water tub  2  along the axial direction of the water tub  2 . Thus, re-circulation passageway  90  that re-circulates air in the water tub  2  need not be curved in great extent especially in the range running from the water tub  2  to the airflow duct  32 , allowing substantially linear installation. Also, the configuration of the entire re-circulation air passageway  90  itself can be simplified as compared to the conventional configuration (the airflow duct being disposed below the water tub to be perpendicular to the axial direction of the water tub). Thus, no increase in conduit resistance is observed inside the re-circulation air passageway  90 , thereby increasing the amount of re-circulation flow being obtained, consequently improving the heat exchange efficiency at the evaporator  41  and the condenser  42  of the heat pump  57  to obtain high dry performance. 
     Also, the compressor  53  of the heat pump  57  is disposed in a position laterally of the airflow duct  32  which is in a direction perpendicular to the axial direction of the water tub  2 . Thus, the compressor  53  of the airflow duct  32  and the heat pump  57  can be disposed space-efficiently in a position below the water tub  2  where there is limited space to reduce the size and weight of the entire drum-type washer/dryer. Also, the compressor  53  may be disposed below the side portion of the water tub  2  and not below the lowermost portion of the water tub  2  where space is most limited, thus, no additional space need to be provided for the compressor  53 . 
     Also, the entrance  60  and the exit  61  of the airflow duct  32  are provided so as to oppose each other and the evaporator  41  and the condenser  42  of the heat pump  57  are disposed between the entrance  60  and the exit  61  so that the centers of the evaporator  41  and the condenser  42  substantially match with the centers of the entrance  60  and the exit  61 . Thus, air supplied from inside the water tub  2  to the airflow duct  32  may pass through the airflow duct  32  more smoothly to prevent air from leaking out of the airflow duct  32 . Also, the air supplied from inside the water tub  2  to the airflow duct  32  can be flown in a substantially linear fashion to the evaporator  41  and the condenser  42  of the heat pump  57 , thereby being efficiently exposed to the evaporator  41  and the condenser  42  to provide further enhanced heat exchange efficiency. 
     Also, the filter case  64  containing the filter  67  is installed in a row with the evaporator  41  and the condenser  42  of the heat pump  57 , and disposed in the upwind of the airflow duct  32 . Thus, air passed through the filter case  64  can be flown substantially in a linear fashion to the airflow duct  32  to prevent reduction in the amount of re-circulation air flow. 
     Further, the compressor  53  of the heat pump  57  is disposed on a bottom plate  35 , being shared with the airflow duct  32 , via a reinforcing plate  54 . Thus, the compressor  53  and the airflow duct  32  can be handled as a single unit. Also, the placement of the compressor  53  prevents bending of the bottom plate  35  of the airflow duct  32 . Hence, air can be prevented from leaking out of the airflow duct  32  by the deformation of the airflow duct  32  due to bottom plate  35  bending. Further, the reinforcing plate  54  reduces damages suffered by the airflow duct  32  even in case the drum-type washer/dryer is dropped, for example, during relocation of the drum-type washer/dryer. 
     Further, the intervention of the reinforcing plate  54  allows secure fixture of the compressor  53  on the bottom plate  35 , thereby preventing the vibration imparted by the drum  13  during the operation of the drum-type washer/dryer, for example, from being transmitted to the airflow duct  32  and the compressor  53 . The conduits connecting the compressor  53 , condenser  42 , and the evaporator  41  can also be protected from transmission of vibration, consequently increasing product lifecycle of the conduits as well as the entire heat pump  57 . Further, vibration originating from the compressor  53  can be prevented from being transmitted to the cabinet  1  to suppress occurrence of vibration and noise of the drum-type washer/dryer in its entirety. 
     The drain reservoir  73  for accumulating condescended dew evaporated from the evaporator  41  is formed on the bottom plate  35  of the airflow duct  32 . Thus, deformation of the airflow duct  32  can be prevented by the support provided to the bottom plate  35  of the airflow duct  32  by the drain reservoir  73 . 
     The condescended dew evaporated from the evaporator  41  can be accumulated in the drain reservoir  73  below the bottom plate  35  of the airflow duct  32  to prevent the evaporator  41  and the condenser  42  from being immersed in the dew. Thus, clogging of lint in the airflow duct  32  (especially, between the heat exchange fins  50  of the evaporator  41  and between the heat exchange fins  51  of the condenser  42 ) can be prevented even if the condescended dew contains lint. 
     Also, the sidewall  37  of the airflow duct  32  comprises the end plate  45  of the evaporator  41 , the end plate  46  of the condenser  42 , and the auxiliary side plate  47  connecting the end plate  45  of the evaporator  41  and the end plate  46  of the condenser  42 . Thus, the portion of the airflow duct  32  configured by the sidewall  37  can be rendered airtight to prevent air leak from the airflow duct  32 . 
     Further, the sidewall  37  of the airflow duct  32  utilizes the end plate  45  of the evaporator  41  and the end plate  46  of the condenser  42 . Thus, no additional elements are required for the sidewall  37  to render a low cost product. Further, by configuring the sidewall  37  by a portion (end plate  45 ) of the evaporator  41  and a portion (end plate  46 ) of the condenser  42 , no space is created between the evaporator  41  and the condenser  42  and the sidewall  37 , allowing efficient exposure of the air circulated in the airflow duct  32  to the evaporator  41  and the condenser  42 . 
     Also, the airflow duct  32  and the compressor  53  have been disposed on the platform  30  via the anti-vibration rubber  31 . Thus, the vibration originating from the drum  13  during the operation of the drum-type washer/dryer can be prevented from being transmitted to the airflow duct  32  and the compressor  53  via the cabinet  1 . 
     Further, since each of the filter bodies  68  constituting the filter  67  have different mesh sizes, both large lint and small lint can be collected. In this case, the filter bodies  68  being detachably attached to the filter frame  69  allow removal of lint accumulated in the filter  67  with greater ease. 
     Yet, further, since the re-circulation flow duct  83  is formed by utilizing the wall of the water tub cover  4 , no additional element is required for the re-circulation flow duct  83 , thereby allowing product cost reduction. 
     Furthermore, since the bottom  73   a  of the drain reservoir  73  is downwardly sloped toward the suction port of the drain pump  75 , dew dripped on the drain reservoir  73  during the dry step can be sucked efficiently by the drain pump  75  to allow quick drainage. 
     The present invention is not limited to the above described embodiment example but may be modified or expanded as follows. 
     The water tub  2  and the drum  13  maybe disposed axially horizontal or inclined. 
     The present invention may be subject to various modifications and extensions without departures from the inventive concept. 
     INDUSTRIAL APPLICABILITY 
     As described above, the drum-type washer/dryer in accordance with the present invention obtains high dry performance as well as overall compactness and light weight, thereby useful in drum-type washer/dryer placed in limited spaces.