Patent Publication Number: US-2007107472-A1

Title: Spray type drum washing machine

Description:
This application is a Divisional of co-pending Application No. 10/822,748, filed on Apr. 13, 2004, the entire contents of which are hereby incorporated by reference and for which priority is claimed under 35 U.S.C. § 120. This application also claims priority under  35  U.S.C. § 119 (a) on Patent Application No. 2003-24911 filed in the Republic of Korea on Apr. 19, 2003 and Patent Application No. 2003-23320 filed in the Republic of Korea on Apr. 14, 2003, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a drum washing machine adapted to wash clothes, and more particularly to a spray type drum washing machine capable of atomizing wash water contained in a tub, and spraying the atomized wash water into a drum, thereby achieving an enhancement in washing performance.  
      2. Description of the Related Art  
      Drum washing machines are generally adapted to wash laundry contained in a drum, such as clothes or bedding, through wash, rinse, and spin-dry cycles, in order to remove contaminants attached to the laundry in accordance with the action of wash water contained in a tub.  
       FIG. 1  is a partially-broken perspective view illustrating a conventional drum washing machine.  FIG. 2  is a sectional view illustrating the conventional drum washing machine.  
      As shown in  FIGS. 1 and 2 , the conventional drum washing machine includes a base  1 , and a cabinet  2  installed on the base  1  while defining the appearance of the washing machine. The cabinet  2  is provided with an access opening  2   a  for loading and unloading of clothes m. The conventional drum washing machine also includes a door  4  hingably mounted to a front wall of the cabinet  2 , and adapted to open and close the access opening  2   a , a tub  6  mounted in the cabinet  2  while being supported by a damper, a water supply unit  10  adapted to supply wash water w into the tub  6 , a drainage unit  12  adapted to drain the wash water w from the tub  2  to the outside of the cabinet  2 , a drum  20  rotatably mounted in the tub  6 , and adapted to contain clothes therein, and a drum motor  30  adapted to rotate the drum  20 .  
      The tub  6  is provided with an access opening  7  arranged in rear of the access opening  2   a  of the cabinet  2  to allow the user to put clothes m into the drum  20  and to take the clothes out of the drum  20 .  
      The drum  20  is also provided with an access opening  21  arranged in rear of the access opening  2   a  of the cabinet  2  to allow the user to put clothes m into the drum  20  and to take the clothes out of the drum  20 . The drum  20  is arranged such that a bottom portion thereof is dipped in wash water contained in the tub  6 . The drum  20  is also formed with a plurality of water holes  22  at peripheral and rear walls thereof to allow wash water to flow between the tub  6  and the drum  20 .  
      Lifters  26  are mounted to an inner peripheral surface of the drum  20 . The lifters  26  serve to raise clothes contained in the drum  20  to the top of the drum  20 , and then to release the clothes, thereby allowing the clothes to be dropped due to gravity.  
      The drum motor  30  is mounted to a rear wall of the tub  6  at the outside of the tub  6 . The drum motor  30  has a rotating shaft  32  extending horizontally or approximately horizontally through a central portion of the rear wall of the tub  6  into the drum  20 . The rotating shaft  32  is connected to a central portion of a rear wall of the drum  20 .  
      In  FIG. 1 , reference numeral  48  designates a gasket mounted to the tub  6 , and adapted to prevent leakage of wash water between the access openings of the door  4  and tub  6  in a closed state of the door  4 .  
      Operation of the conventional drum washing machine having the above described configuration will now be described.  
      When the drum washing machine is operated under the condition in which the door  4  has been closed after clothes m have been put into the drum  20 , wash water is supplied into the tub  6  in accordance with operation of the water supply unit  10 , so that it is contained in a bottom portion of the tub  6 . In this state, the bottom portion of the drum  20  is also dipped in the wash water as the wash water is introduced into the drum  20  through the water holes  22 . As a result, the clothes in the drum  20  are wetted by the wash water.  
      Thereafter, the motor  30  is driven to rotate the drum  20 . Thus, the clothes m contained in the drum  20  are repeatedly raised and dropped in the drum  20 . As a result, stains are removed from the clothes m in accordance with the frictional action of the wash water and the inner surface of the drum  20 .  
      After completion of this wash cycle, the wash water existing in the water tub  10  in a contaminated state is externally drained from the drum washing machine through the drainage unit  12 .  
      Subsequently, the drum washing machine performs, several times, a rinse cycle for rinsing the washed clothes m to remove bubbles remaining on the clothes m. In this rinse cycle, wash water is supplied into the tub  6  by the water supply unit  10 . Thereafter, the drum motor  30  is driven to rotate the drum  20 , thereby causing the clothes m contained in the drum  20  to be repeatedly raised and dropped in the drum  20 . As a result, bubbles are removed from the clothes m.  
      The contaminated wash water containing the removed bubbles is externally drained from the washing machine through the drainage unit  12 .  
      After performing the rinse cycle several times, the washing machine performs a spin-dry cycle to remove moisture form the clothes m.  
      That is, when the drum motor  30  rotates the drum  20  at high speed, moisture permeated into the clothes m is centrifugally removed from the clothes m, and then collected in the tub  6  after being discharged from the drum  20  through the water holes  22 . Finally, the collected moisture is externally drained through the drainage unit  12 .  
      In the above mentioned conventional drum washing machine, however, there is a problem in that the clothes put into the drum  20  are simply naturally wetted by wash water supplied into the drum  20  or contained in the tub  6 . That is, detergent supplied into the drum  20  is insufficiently dissolved in the wash water. Also, the speed, at which wash water permeates the clothes, is low.  
      Furthermore, although washing of clothes is carried out in the conventional drum washing machine, using wash water contained in the tub  6 , a part of the wash water contained in the tub  6  may be insufficiently used in the clothes washing process. In order to obtain sufficient washing performance, it is necessary to use a large amount of wash water.  
     SUMMARY OF THE INVENTION  
      Therefore, the present invention has been made in view of the above mentioned problems involved with the related art, and it is an object of the invention to provide a spray type drum washing machine in which wash water contained in a tub is atomized to be sprayed into a drum, thereby being capable of achieving an enhancement in washing and rinsing efficiencies while using a reduced amount of wash water in accordance with circulation of the sprayed wash water.  
      Another object of the invention is to provide a spray type drum washing machine in which wash water circulating in the drum washing machine is heated to generate steam, and the generated steam is sprayed into the drum, thereby being capable of achieving an enhancement in washing and sterilization performances.  
      In accordance with one aspect, the present invention provides a spray type drum washing machine comprising: a cabinet; a tub mounted in the cabinet, and adapted to contain wash water therein; a circulation line connected between a portion of the tub and another portion of the tub to circulate wash water through the tub; a pump installed at the circulation line, and adapted to forcibly feed wash water through the circulation line for the circulation of the wash water through the tub; and atomizing means provided at the circulation line, and adapted to atomize the wash water fed through the circulation line, whereby the wash water to circulate through the tub is supplied in an atomized state into the tub.  
      The atomizing means may comprise a case arranged at the circulation line, and adapted to allow wash water to pass therethrough, diffusion means provided at an inlet portion of the case, and adapted to diffuse wash water to be introduced into the case, thereby atomizing the wash water, and a blowing fan adapted to forcibly feed, into the tub, the atomized wash water emerging from the diffusion means.  
      The diffusion means may comprise at least one centrifugal plate adapted to be rotated about an axis passing through a center thereof by a driving force, and a diffusion net arranged around the centrifugal plate, and adapted to diffuse wash water radially projected from the centrifugal plate in an atomized state.  
      The at least one centrifugal plate may comprise a plurality of centrifugal plates axially spaced apart from one another.  
      The centrifugal plate and the blowing fan may be rotated by a dual-shaft motor adapted to generate the driving force.  
      The circulation line may be provided, at an outlet end thereof, with a diffusion nozzle.  
      The spray type drum washing machine may further comprise a steam generating device installed at the circulation line, and adapted to heat the atomized wash water emerging from the atomizing means, thereby changing the atomized wash water into steam, and to supply the steam into the tub.  
      The steam generating device may comprise a container arranged at the circulation line, and adapted to allow the atomized wash water emerging from the atomizing means to pass therethrough, and a heater adapted to heat the atomized wash water passing through the container.  
      The steam generating device may further comprise temperature sensing means adapted to measure an internal temperature of the container.  
      In accordance with another aspect, the present invention provides a spray type drum washing machine comprising: a cabinet; a tub mounted in the cabinet, and adapted to contain wash water therein; a circulation line connected between a portion of the tub and another portion of the tub to circulate wash water through the tub; a pump installed at the circulation line, and adapted to forcibly feed wash water through the circulation line for the circulation of the wash water through the tub; atomizing means provided at the circulation line, and adapted to atomize the wash water to circulate through the tub; and steam generating means installed at the circulation line, and adapted to heat the atomized wash water emerging from the atomizing means, thereby changing the atomized wash water into steam, and to supply the steam into the tub.  
      In accordance with still another aspect, the present invention provides a spray type drum washing machine comprising: a cabinet; a tub mounted in the cabinet while carrying a drum therein, and adapted to contain wash water therein; a circulation line connected between bottom and top portions of the tub to circulate wash water through the tub; a pump installed at the circulation line, and adapted to forcibly feed wash water through the circulation line for the circulation of the wash water through the tub; atomizing means provided at the circulation line downstream from of the pump, and adapted to atomize the wash water to circulate through the tub; and a diffusion nozzle provided at an outlet end of the circulation line, and adapted to spray, into the tub, the wash water atomized while passing through the atomizing means.  
      The atomizing means may comprise a case arranged at the circulation line, and adapted to allow wash water to pass therethrough, at least one centrifugal plate arranged in the case, and adapted to centrifugally radially project the wash water introduced into the case, a diffusion net arranged around the centrifugal plate, and adapted to atomize the wash water centrifugally radially projected from the centrifugal plate when the wash water passes therethrough, a blowing fan adapted to forcibly feed, into the tub, the atomized wash water emerging from the diffusion net, and drive means adapted to rotate the centrifugal plate and the blowing fan.  
      The spray type drum washing machine may further comprise steam generating means installed at the circulation line, and adapted to heat the atomized wash water emerging from the atomizing means, thereby changing the atomized wash water into steam, and to supply the steam into the tub.  
      The steam generating device may comprise a container arranged at the circulation line, and adapted to allow the atomized wash water emerging from the atomizing means to pass therethrough, a heater adapted to heat the atomized wash water passing through the container, temperature sensing means adapted to measure an internal temperature of the container, and control means adapted to control the heater in accordance with a signal outputted from the temperature sensing means.  
      In the spray type drum washing machine according to one aspect of the present invention, wash water discharged from the tub is centrifugally radially projected by the centrifugal plates, and is then atomized while passing through the diffusion net. The atomized wash water is forcibly fed by the blowing fan so that it is sprayed into the drum. Accordingly, the wash water can rapidly permeate clothes contained in the drum, so that it can more effectively come into contact with contaminants attached to the clothes. As a result, it is possible to achieve an enhancement in washing and rinsing performances while reducing the consumption of wash water.  
      In the spray type drum washing machine according to another aspect of the present invention, wash water is atomized in the circulation line connected between the bottom and top of the tub to circulate wash water through the tub, and is then heated while passing through the container heated by the heater, so that steam is generated. Thus, hot steam is sprayed into the tub at the top of the tub. Accordingly, it is possible to rapidly wet clothes with wash water while obtaining enhanced sterilization and washing effects.  
      Since wash water particle formed in accordance with the atomization of wash water is changed into steam as it is heated, it is possible to effectively perform washing of clothes at high temperature, using a reduced amount of wash water. Accordingly, it is possible to reduce waste of wash water and electrical energy. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above objects, and other features and advantages of the present invention will become more apparent after reading the following detailed description when taken in conjunction with the drawings, in which:  
       FIG. 1  is a partially-broken perspective view illustrating a conventional drum washing machine;  
       FIG. 2  is a sectional view illustrating the conventional drum washing machine;  
       FIG. 3  is a partially-broken perspective view illustrating a spray type drum washing machine according to an embodiment of the present invention;  
       FIG. 4  is a sectional view illustrating the spray type drum washing machine according to the embodiment of the present invention;  
       FIG. 5  is a sectional view illustrating an atomizing device and a circulation line included in the spray type drum washing machine according to the embodiment of the present invention;  
       FIG. 6  is an exploded perspective view illustrating the atomizing device and circulation line included in the spray type drum washing machine according to the embodiment of the present invention;  
       FIG. 7  is a partially-broken perspective view illustrating a spray type drum washing machine according to another embodiment of the present invention;  
       FIG. 8  is a sectional view illustrating the spray type drum washing machine according to the embodiment of the present invention illustrated in  FIG. 7 ;  
       FIG. 9  is a sectional view illustrating an atomizing device included in the spray type drum washing machine according to the embodiment of the present invention illustrated in  FIG. 7 ; and  
       FIG. 10  is a sectional view illustrating a steam generating device included in the spray type drum washing machine according to the embodiment of the present invention illustrated in  FIG. 7 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Now, embodiments of a spray type drum washing machine according to the present invention will be described in detail with reference to the annexed drawings.  
       FIG. 3  is a partially-broken perspective view illustrating a spray type drum washing machine according to an exemplary embodiment of the present invention.  FIG. 4  is a sectional view illustrating the spray type drum washing machine according to the illustrated embodiment of the present invention.  
      As shown in  FIGS. 3 and 4 , the spray type drum washing machine according to the illustrated embodiment of the present invention includes a base  51 , and a cabinet  52  installed on the base  51  while defining the appearance of the drum washing machine. The cabinet  2  is provided at a front wall thereof with an access opening  54  for loading and unloading of clothes m. A door  56  is hingably mounted to the front wall of the cabinet  52  to open and close the access opening  54 .  
      A tub  60  is mounted in the cabinet  52  to contain wash water w therein.  
      The tub  60  is provided with an access opening  62  arranged in rear of the access opening  54  of the cabinet  52  to allow the user to perform loading and unloading of clothes m therethrough. A gasket  64  is fitted around the access opening  62  of the tub  60  to prevent wash water from being leaked between the door  56  and the access opening  54 . The tub  60  is connected, at the bottom thereof, to a damper  66  mounted to the base  51  so that it is supported by the base  51  in a dampable state. The tub  60  is also connected, at the top thereof, to the top of the cabinet  52  via a spring  68  such that it is supported by the cabinet  52  in a suspended state while being dampable.  
      A drum  70  is arranged in the tub  60  to contain clothes.  
      The drum  70  is provided with an access opening  72  arranged in rear of the access openings  54  and  62  of the cabinet  52  and tub  60  to allow the user to put clothes m into the drum  70  and to take the clothes out of the drum  70 . The drum  70  is also formed with a plurality of water holes  74  at peripheral and rear walls thereof to allow wash water to flow between the tub  60  and the drum  70 . Lifters  76  are mounted to an inner peripheral surface of the drum  70 . The lifters  76  serve to raise clothes contained in the drum  70  to the top of the drum  70 , and then to release the clothes, thereby allowing the clothes to be dropped due to gravity.  
      The spray type drum washing machine also includes a drum motor  80  adapted to generate a drive force for rotating the drum  70 .  
      The drum motor  80  is mounted to a rear wall of the tub  60  at the outside of the tub  60 . The drum motor  80  has a rotating shaft  82  extending horizontally or approximately horizontally through a central portion of the rear wall of the tub  60  into the drum  70 . The rotating shaft  82  is connected to a central portion of a rear wall of the drum  70 .  
      Alternatively, the drum motor  80  may be mounted to the bottom of the tub  60 , as compared to the above case in which the drum motor  80  is mounted to the rear wall of the tub  60 . In this case, a separate shaft (not shown) is rotatably mounted to the rear wall of the tub  60  to extend horizontally or approximately horizontally through the central portion of the rear wall of the tub  60  into the drum  70 . The shaft is connected to the rotating shaft of the drum motor  80  via a belt.  
      The spray type drum washing machine further includes a water supply unit  90  adapted to supply wash water into the tub  60 , a heater  100  installed at the bottom of the tub  60  inside the tub  60 , and adapted to heat wash water contained in the tub  60 , a drainage unit  110  adapted to drain wash water from the tub  60  to the outside of the cabinet  52 , an atomizing device  120  adapted to atomize wash water drained from the tub  60 , a circulation line adapted to supply wash water from the tub  60  to the atomizing device  120 , and to supply the atomized wash water into the drum  70 , thereby circulating the wash water, and a pump  122  installed at the circulation line  133 , and adapted to cause wash water to flow forcibly along the circulation line  133 .  
      The water supply unit  90  includes a water supply hose  94  adapted to guide wash water, a detergent box  96  provided with a water supply passage for receiving wash water supplied through the water supply hose  94 , and a detergent storing space communicating with an outlet of the water supply passage while being adapted to store detergent therein, and a water supply bellows  98  communicating with the tub  60  to guide wash water emerging from the detergent box  96  into the tub  60 .  
      The drainage unit  110  includes a drainage bellows  112  communicating with a bottom portion of the tub  60  to drain wash water from the tub  60 , a drainage pump  114  adapted to pump wash water drained from the tub  60  through the drainage bellows  112 , and a drainage hose  116  adapted to guide the wash water emerging from the drainage pump  114  to the outside of the drum washing machine. In place of the drainage pump  114 , a drainage valve may be used. In this case, the drainage valve opens or closes the drainage bellows  112  to allow or prevent drainage of wash water from the tub  60  through the drainage bellows  112 .  
      The atomizing device  120  and circulation line  133  will be described in detail with reference to  FIGS. 5 and 6 .  
       FIG. 5  is a sectional view illustrating the atomizing device and circulation line.  FIG. 6  is an exploded perspective view illustrating the atomizing device.  
      As shown in FIGS.  3  to  6 , the atomizing device  120  includes a diffusion means including a case, through which wash water pumped by the pump  122  passes, centrifugal plates  124  adapted to centrifugally radially project wash water introduced into the case, and a diffusion net  126  arranged around the centrifugal plates  124 , and adapted to atomize the wash water centrifugally radially projected from the centrifugal plates  124  when the projected wash water passes therethrough, a blowing fan  128  adapted to forcibly feed, into the tub  60 , the wash water atomized while passing through the diffusion net  126 , and a drive means adapted to rotate both the centrifugal plates  124  and the blowing fan  128 , for example, a dual-shaft motor  130 .  
      The case includes a net case  136  arranged around the diffusion net  126  to define a flow passage for guiding the atomized wash water, and a fan case  138  coupled to the net case  136 , and arranged around the blowing fan  128  to define a flow passage for guiding the atomized wash water forcibly fed by the blowing fan  128 .  
      As shown in  FIG. 5 , the centrifugal plates  124  are spaced apart from each other. Although two centrifugal plates  124  are shown in  FIG. 5 , an increased number of centrifugal plates may be used. Of course, a single centrifugal plate may be used. However, the former case is preferable because wash water flowing from one centrifugal plate  124  to another centrifugal plate  124  arranged downstream from the one centrifugal plate  124  along a peripheral edge of the upstream centrifugal plate  124  without being centrifugally radially projected can be centrifugally radially re-projected from the upstream plate  124 , along with wash water returned to the upstream plate  124  after striking the diffusion net  126 .  
      As shown in  FIGS. 5 and 6 , the diffusion net  126  may have a circular strip structure having a height greater than the total height of the centrifugal plates  124  such that it completely surround the centrifugal plates  124 . Alternatively, the diffusion net  126  may have a top portion upwardly spaced apart from an uppermost one of the centrifugal plates  124 , a bottom portion downwardly spaced apart from a lowermost one of the centrifugal plates  124 , and a peripheral portion arranged around the centrifugal plates  124 , so that the diffusion net  126  completely surrounds the centrifugal plates  124 .  
      As shown in  FIGS. 5 and 6 , the dual-shaft motor  130  includes a rotating shaft  131   a  extending axially through respective rotating centers of the centrifugal plates  124  to firmly support the centrifugal plates  124 , and a rotating shaft  131   b  extending axially through a rotating center of the blowing fan  126  to firmly support the blowing fan  126 , as shown in  FIGS. 5 and 6 . The dual-shaft motor  130  is arranged between the centrifugal plates  124  and the blowing fan  128 .  
      As shown in FIGS.  3  to  6 , the circulation line  133  includes a pump hose  132  connected, at one end thereof, to a drainage port formed at the tub  60  while being connected, at the other end thereof, to an inlet of the pump  122 , in order to guide wash water from the tub  60  into the pump  122 . The circulation line  133  also includes a first circulation pipe  134  connected, at one end thereof, to an outlet of the pump  122  while being connected, at the other end thereof, to the net case  136  such that the other end thereof is spaced apart from the centrifugal plates  124 . The first circulation pipe  134  guides wash water pumped by the pump  122  into the net case  136 . The circulation line  133  further includes a second circulation pipe  140  adapted to guide, into the drum  70 , wash water forcibly fed by the blowing fan  128  in an atomized state.  
      The pump hose  132  may have, at a middle portion thereof, a bellows portion to prevent the ends thereof connected to the tub  60  and pump  122  from being separated from the tub  60  and pump  122 .  
      The first circulation pipe  134  extends through the net case  136  such that the end thereof arranged in the interior of the net case  136  is spaced apart from a lower surface of the lowermost centrifugal plate  124 .  
      The net case  136  is provided, at a wall thereof, with a through hole  136   a  adapted to allow the first circulation pipe  134  to extend therethrough. In the illustrated case, the through hole  136   a  is formed at the bottom wall  136   c  of the net case  136 . The net case  136  is also provided, at a wall thereof facing the fan case  138 , that is, the top wall thereof, with an opening  136   b  adapted to allow the forcibly fed atomized wash water to be introduced into the fan case  138 . The net case  136  is also provided with a suction hole  136   e , at the wall thereof having the through hole  136   a , that is, the bottom wall  136   c  thereof, to suck air into the interior of the net case  136 . Although the suction hole  136   e  is formed at the bottom wall  136   c  of the net case  136  in the illustrated case, it may be formed at a peripheral wall  136   d  of the net case  136 .  
      The fan case  138  is provided, at a wall thereof facing the net case  136 , that is, the bottom wall thereof, with an opening  138   a  to receive the atomized wash water from the net case  136 . A discharge hole  138   b  is provided at the top wall of the fan case  138  to discharge the atomized wash water from the fan case  138 .  
      The second circulation pipe  140  is connected, at one end thereof, to the discharge hole  138   b  of the fan case  138 . The second circulation pipe  140  extends upwardly from the discharge hole  138   b  such that the other end thereof is upwardly protruded through a top portion of the gasket  64 .  
      As shown in  FIGS. 3 and 4 , it is preferred that the other end of the second circulation pipe  140  be inclinedly arranged toward the center of the interior of the drum  70 .  
      A trumpet-shaped diffusion nozzle  146  is mounted to the other end of the second circulation pipe  140  to allow the atomized wash water injected into the interior of the drum  70  to be spread in a diffused state.  
      In  FIGS. 5 and 6 , reference numeral  152  designates support rods adapted to firmly hold the diffusion net  126  in the net case  136  in a state of being spaced apart from the bottom of the net case  136 . Reference numeral  154  designates a motor mounting member adapted to fixedly mount the dual-shaft motor  130  to the fan case  138 .  
      Now, operation of the drum washing machine having the above described configuration according to the illustrated embodiment of the present invention will be described.  
      When the drum washing machine is operated under the condition in which the door  56  has been closed after clothes m have been put into the drum  70 , as shown in  FIGS. 3 and 4 , wash water is supplied from the water supply unit  90  into the tub  6 , so that it is contained in a bottom portion of the tub  6  while being contained in the pump hose  132 .  
      In this state, the bottom portion of the drum  70  is also dipped in the wash water as the wash water is introduced into the drum  70  through the water holes  74 . As a result, the clothes in the drum  70  are wetted by the wash water.  
      Thereafter, the drum motor  80  is driven to rotate the drum  70 . Thus, the clothes m contained in the drum  70  are repeatedly raised and dropped in the drum  70 . As a result, stains are removed from the clothes m in accordance with action of the wash water.  
      Meanwhile, both the pump  122  and the dual-shaft motor  130  are driven during the above described water supply cycle or wash cycle executed in the spray type drum washing machine. Accordingly, the wash water in the tub  60  is pumped by the pump  122 . Also, the centrifugal plates  124  and blowing fan  128  are rotated in accordance with the operation of the dual-shaft motor  130 .  
      The wash water pumped by the pump  122  is guided into the net case  136  via the first circulation pipe  134 , and then strikes one surface of each centrifugal plate  124 . Thereafter, the wash water is centrifugally radially projected toward the diffusion net  126  while being guided by the centrifugal plates  124 , so that it is atomized while passing through the diffusion net  126 .  
      The wash water atomized while passing through the diffusion net  126  is forcibly fed by the blowing fan  128  so that it is introduced into the second circulation pipe  140 .  
      The atomized wash water is then sprayed in the form of rain or mist into the drum  70  through the gasket  64  as it is discharged from the second circulation pipe  140 .  
      The atomized wash water sprayed into the drum  70  through the gasket  64  directly wets the clothes m contained in the drum  70 , so that it rapidly reacts upon contaminants attached to the clothes m, thereby enhancing the washability thereof.  
      After completion of the above described wash cycle, the wash water existing in the tub  60  in a contaminated state is externally drained from the tub  60  through the drainage unit  110 .  
      Subsequently, the spray type drum washing machine performs, several times, a rinse cycle for rinsing the washed clothes m to remove bubbles remaining on the clothes m. In this rinse cycle, wash water is supplied into the tub  60  through the water supply unit  90 . Thereafter, the drum motor  80  is driven to rotate the drum  70 , thereby causing the clothes m contained in the drum  70  to be repeatedly raised and dropped in the drum  70 . As a result, bubbles are removed from the clothes m.  
      Meanwhile, both the pump  122  and the dual-shaft motor  130  are driven during the above described water supply cycle or rinse cycle executed in the spray type drum washing machine. Similarly to the wash cycle, accordingly, the wash water in the tub  60  is pumped by the pump  122 , and then atomized by the centrifugal plates  124  and diffusion net  126 . Subsequently, the atomized wash water directly wets the clothes m contained in the drum  70 , so that it rapidly rinses the clothes m to remove bubbles from the clothes m in accordance with an enhanced rinse ability thereof.  
      After completion of the above described rinse cycle, the wash water existing in the tub  60  in a contaminated state is externally drained from the tub  60  through the drainage unit  110 .  
      After performing the rinse cycle several times, the drum washing machine performs a spin-dry cycle to remove moisture form the clothes m. That is, when the drum motor  80  rotates the drum  70  at high speed, moisture permeated into the clothes m is centrifugally removed from the clothes m, and then collected in the bottom portion of the tub  60  after being discharged from the drum  70  through the water holes  74 . Finally, the collected moisture is externally drained through the drainage unit  110 .  
       FIG. 7  is a partially-broken perspective view illustrating a spray type drum washing machine according to another embodiment of the present invention.  FIG. 8  is a sectional view illustrating the spray type drum washing machine according to the embodiment of the present invention illustrated in  FIG. 7 .  
      As shown in  FIGS. 7 and 8 , the spray type drum washing machine according to this embodiment of the present invention includes a cabinet  152  defining the appearance of the drum washing machine, and a tub  156  mounted in the cabinet  152  such that it is connected, at the top thereof, to the top of the cabinet  152  via a spring  154  in a suspended state while being supported by a damper  155 . The drum washing machine also includes a drum  158  rotatably mounted in the tub  156 , and adapted to contain wash water and clothes m to be washed, and lifters  159  mounted to an inner peripheral surface of the drum  158  such that they are radially protruded from the inner peripheral surface of the drum  158  while being circumferentially uniformly spaced apart from one another. The lifters  159  serve to raise clothes contained in the drum  158  to the top of the drum  158 , and then to release the clothes, thereby allowing the clothes to be dropped. The drum washing machine further includes a drum motor  160  connected with the drum  158 , and adapted to rotate the drum  158 , a water supply unit  162 , and a detergent box  164 . The water supply unit  162  and detergent box  164  are arranged above the tub  156  to simultaneously supply wash water and detergent into the tub  156  and drum  158 .  
      The spray type drum washing machine further includes a circulation pump  170  installed at a circulation line  172  adapted to connect the bottom and top of the tub  156 , and adapted to pump wash water from the bottom of the tub  156  to the top of the tub  156  via the circulation line  172  or to drain wash water from the tub  156  via a drainage line  174 , an atomizing device  180  installed at the circulation line  172  such that it is connected to the circulation pump  170 , and adapted to atomize wash water discharged from the circulation pump  170 , and a steam generating device  190  installed at the circulation line  172  such that it is connected to the atomizing device  180 , and adapted to heat wash water particulates emerging from the atomizing device  180 , thereby changing the wash water particulates into steam.  
      The circulation line  172  extends vertically to connect the bottom and top of the tub  156 . The circulation pump  170  is installed at a lower portion of the circulation line  172  connected to the bottom of the tub  156 . The atomizing device  180  is installed at the circulation line  172  downstream from the circulation pump  170 . The steam generating device  190  is installed at an upper portion of the circulation line  172  connected to the top of the tub  156 .  
      The atomizing device  180  and steam generating device  190  will be described in detail with reference to  FIGS. 9 and 10 .  
       FIG. 9  is a sectional view illustrating the atomizing device.  FIG. 10  is a sectional view illustrating the steam generating device.  
      The atomizing device  180  includes a case  182  installed at the circulation line  172  while being provided at a peripheral wall thereof with a suction port  181  for receiving wash water, and at a top wall thereof with a discharge port  183  for discharging wash water particulates, a blowing fan  184  rotatably mounted in the case  182 , and adapted to blow the wash water particulates, and a dual-shaft motor  185  mounted in the case  182  beneath the blowing fan  184  such that it is connected with the blowing fan  184 , and adapted to rotate the blowing fan  184 . The atomizing device  180  also includes a plurality of centrifugal plates  186  arranged in the case  182  beneath the dual-shaft motor  185  such that it is connected to the dual-shaft motor  185 , and adapted to rotate simultaneously with the blowing fan  184 , thereby radially projecting the wash water introduced into the case  182  in accordance with a centrifugal force caused by the rotation thereof, and a diffusion net  188  arranged around the centrifugal plates  186  in a state of being spaced apart from the centrifugal plates  186 , and adapted to atomize the wash water radially projected from the centrifugal plates  186 .  
      The dual-shaft motor  185  is arranged in the case  182  in a state of being radially supported by the case  182 . The dual-shaft motor  185  has upper and lower rotating shafts respectively connected to the blowing fan  184  and the centrifugal plates  186 .  
      In  FIG. 9 , reference numeral  189  designates a motor mounting member adapted to mount the dual-shaft motor  185  to the case  182 .  
      The steam generating device  190  includes a container  192  having an inlet  191  adapted to receive wash water particulates discharged from the atomizing device  180 , and an outlet  193  arranged opposite to the inlet  191 , and adapted to discharge steam, a heater  194  arranged on an outer surface of the container  192 , and adapted to heat the container  192 , and a temperature sensor  196  adapted to sense an internal temperature of the container  192 , thereby allowing a control unit included in the drum washing machine to control operation of the heater  194 , based on the temperature of steam existing in the container  192 .  
      Of course, the container  192  is made of a material exhibiting a relatively high heat transfer coefficient. The heater  194  may be mounted to the bottom of the container  192 . Also, the temperature sensor  196  may be mounted to the top of the container  192  while being electrically connected to the heater  194 .  
      Meanwhile, the circulation line  172  extends, at an upper end thereof, through a gasket  175  arranged between the tub  156  and the cabinet  152  to prevent leakage of wash water. A diffusion nozzle  173  adapted to spray wash water or steam is mounted to the upper end of the circulation line  172  such that it is directed from the top and front end of the tub  156  toward the bottom and rear end of the tub  156 .  
      Now, operation of the drum washing machine having the above described configuration according to the embodiment of the present invention illustrated in FIGS.  7  to  10  will be described.  
      When a wash cycle is begun under the condition in which clothes m have been put into the drum  158 , a water supply valve (not shown) is opened, so that wash water is introduced into the water supply unit  162  and detergent box  164 . As a result, the wash water is supplied into the tub  156  and drum  158 , along with detergent. The amount of wash water supplied into the tub  156  is appropriately determined, based on the amount of clothes contained in the tub  156 .  
      Under the condition in which an appropriate amount wash water has been supplied into the tub  156 , the drum motor  160  is operated to rotate the drum  158 . In accordance with the rotation of the drum  158 , the lifters  159  raise the clothes m contained in the drum  158 , and then release the clothes m at a certain level in the drum  158 , thereby allowing the clothes m to be dropped. Thus, the wash cycle is executed.  
      When the circulation pump  170  is operated during the execution of the wash cycle in accordance with an associated operating condition set by the user, the wash water contained in the tub  156  is pumped from the bottom of the tub  156  to the top of the tub  156 , and sprayed into the tub  156 , so that effective flows of wash water are formed. In addition to such effective flows of wash water, an effect of beating the clothes m with the wash water is generated. Thus, an enhancement in washing performance is obtained.  
      In accordance with the operating condition set by the user, the dual-shaft motor  185  and heater  194  are operated, simultaneously with the operation of the circulation pump  170  to pump wash water into the circulation line  172 . Accordingly, the wash water introduced from the bottom of the tub  156  into the circulation line  172  is sprayed into the tub  156  at the top of the tub  156  after being atomized and then changed into steam while sequentially passing through the atomizing device  180  and steam generating device  190 .  
      This will be described in more detail. The wash water pumped by the circulation pump  170  is introduced into the case  182  via the circulation line  172 . As the dual-shaft motor  185  operates, the blowing fan  184  and centrifugal plates  186  are rotated. As a result, the wash water introduced into the case  182  is radially projected after striking the centrifugal plates  186 , and is than atomized in the form of particulates while passing through the diffusion net  188 . The wash water particulates emerging from the diffusion net  188  are then discharged from the case  182  by the blowing fan  184 . Thus, the wash water particulates are discharged from the atomizing device  180 .  
      The wash water particulates discharged from the atomizing device  180  are introduced into the container  192  via the circulation line  172 . As the heater  194  operates, the wash water particulates are heated while passing through the container  192 , so that they are changed into hot steam. The hot steam is then sprayed into the tub  156  at the top of the tub  156  after passing through the circulation line  172 .  
      Of course, the heater  194  is controlled by the temperature sensor  196 , based on the temperature of steam in the container  192 .  
      Thus, wash water is pumped from the bottom of the tub  156  during the wash cycle to pass through the atomizing device  180  and steam generating device  190 , so that it is changed into hot steam, and then sprayed into the tub  156  at the top of the tub  156 . Accordingly, it is possible to achieve an enhancement in washing and sterilization performances.  
      Where the above procedure is carried out prior to the supply of wash water into the tub  156 , it is possible to rapidly wet the clothes by the hot steam, and thus, to achieve an enhancement in washing performance.  
      After completion of the wash cycle, the circulation pump  170  is operated in a state of being connected to the drainage line  174 , so that it drains the wash water contained in the tub  156 . After the drainage of wash water, the drum motor  160  is driven at high speed, so that the drum  158  is rotated at high speed to perform an intermittent spin-dry cycle for extracting wash water from the clothes in accordance with a centrifugal force generated during the rotation of the drum  158 . After the spin-dry cycle, the water supply valve is re-opened to supply wash water into the drum  158 . Simultaneously, the drum  158  is rotated. Thus, a rinse cycle is executed.  
      After repeated execution of the rinse cycle and intermittent spin-dry cycle, a spin-dry cycle is finally executed. Thus, washing of the clothes is completed.  
      As apparent from the above description, in the spray type drum washing machine according to the first embodiment of the present invention, wash water discharged from the tub is centrifugally radially projected by the centrifugal plates, and is then atomized while passing through the diffusion net. The atomized wash water is forcibly fed by the blowing fan so that it is sprayed into the drum. Accordingly, the wash water can rapidly permeate clothes contained in the drum, so that it can more effectively come into contact with contaminants attached to the clothes. As a result, it is possible to achieve an enhancement in washing and rinsing performances while reducing the consumption of wash water.  
      In the spray type drum washing machine according to the second embodiment of the present invention, wash water is atomized in the circulation line connected between the bottom and top of the tub to circulate wash water through the tub, and is then heated while passing through the container heated by the heater, so that steam is generated. Thus, hot steam is sprayed into the tub at the top of the tub. Accordingly, it is possible to rapidly wet clothes with wash water while obtaining enhanced sterilization and washing effects.  
      Since wash water particle formed in accordance with the atomization of wash water is changed into steam as it is heated, it is possible to effectively perform washing of clothes at high temperature, using a reduced amount of wash water. Accordingly, it is possible to reduce waste of wash water and electrical energy.  
      Although the preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.