Patent Publication Number: US-8109119-B2

Title: Steam generating device and washing machine having the same

Description:
This application claims the benefit of Korean Patent Application No. 10-2006-0058060, filed on Jun. 27, 2006, which is hereby incorporated by reference as if fully set forth herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a steam generating device and a washing machine having the same, and more particularly to a steam generating device which can easily generate steam to be supplied to a washing machine, can be easily installed, and can prevent malfunction of a water level sensor, and a washing machine having the steam generating device. 
     2. Discussion of the Related Art 
     Generally, washing machines are classified into a pulsator type, in which a washing operation is carried out using a flow of water generated in accordance with the rotation of a pulsator, and a drum type, in which a washing operation is carried out using the heads of wash water and laundry falling down in a horizontally-installed drum and frictional force generated between the drum and the laundry during rotation of the drum. 
     Recently, a washing machine, in particular, a drum washing machine, which has a function capable of washing laundry using steam, has been proposed. When steam is used in a washing operation, as in such a washing machine, it is possible to reduce the consumption of water and electricity, to achieve an enhancement in washing performance, to remove creases and odor, and to prevent generation of static electricity. 
     A general drum washing machine using steam will be described hereinafter with reference to  FIG. 8 . 
     The drum washing machine includes a cabinet  10  forming an appearance of the washing machine, a cylindrical tub  20  horizontally supported by the cabinet  10  in the interior of the cabinet  10 , to store wash water, a drum  30  rotatably installed in the tub  20 , and a drive motor (not shown) for driving the drum  30 . 
     An inlet  13  is formed at a front side of the cabinet  10 . The inlet  13  communicates with the interior of the drum  30  so that laundry can be put into or taken out of the drum  30  through the inlet  13 . A door  11  is mounted to the inlet  13 , to open or close the inlet  13 . 
     Water supply valves  15  are provided at one side of the drum washing machine. The water supply valves  15  are connected to external water pipes (not shown), respectively, so as to supply water to the tub  20 . The water valves  15  are connected to a detergent box  27  via a hot water pipe  25   a  and a cold water pipe  26 , respectively. 
     The drum washing machine also includes a steam generating device  50  for supplying steam to the drum  30 . A water supply hose  25  and a steam hose  53  are connected to the steam generating device  50 . The water supply hose  25  supplies water to the steam generating device  50 , whereas the steam hose  53  supplies steam generated from the steam generating device  50  to the drum  30 . 
     The configuration of the steam generating device  50  will be described in more detail with reference to  FIGS. 9 and 10 . 
     The steam generating device  50  includes a case  80 . The case  80  includes a lower housing  81  forming an appearance of the steam generating device  50  and an upper housing  82  coupled to an upper end of the lower housing  81 . A space for storing water is defined in the lower housing  81 . The steam generating device  50  also includes a heater  55  for heating water stored in the case  80 . 
     A water supply port  52   b  is formed at one side of the housing  82 . The water supply port  52   b  is connected to the water supply hose  25 , to introduce water from the water support hose  25  into the steam generating device  50 . A steam discharge port  52   a  is formed at the other side of the housing  82 . The steam discharge port  52   a  is connected to the steam hose  53 , to supply steam from the steam hose  53  to the drum  20 . 
     A water level sensor  60  and a temperature sensor  57  are installed at one side of the upper housing  82 . The water level sensor  60  senses the level of water stored in the steam generating device  50 . The temperature sensor  57  measures the temperature of water heated by the heater  55  and the temperature of steam generated in accordance with the heating of the water. 
     The water level sensor  60  includes a receptacle housing  61  forming an appearance of the water level sensor  60 . The receptacle housing  61  is fixedly mounted to the steam generating device  50 . The water level sensor  60  also includes electrodes arranged in the receptacle housing  61  such that they extend downwardly, to sense the level of water stored in the steam generating device  50 . 
     The electrodes comprise at least a common electrode  62  functioning as a reference electrode for sensing a water level, a low-water-level electrode  63  for sensing a low water level, and a high-water-level electrode  64  for sensing a high water level. 
     When water boils, air bubbles may be abruptly generated, and may be attached to the electrodes  62 ,  63 , and  64 . In this case, the electrodes  62 ,  63 , and  64  may malfunction. Furthermore, it is difficult to completely prevent generation of vibration during operation of the washing machine. For this reason, the steam generating device  50  may also vibrate during operation of the washing machine, so that the water stored in the steam generating device  50  may roll. 
     In order to prevent the water level sensor  60  from malfunctioning due to the above-mentioned factors, a receptacle  70  is provided. The receptacle  70  is configured to enclose the electrodes  62 ,  63 , and  64 . The receptacle  70  also has an opening  70   s.    
     As shown in  FIG. 9 , the receptacle  70  includes an upper receptacle  71  extending downwardly from the upper housing  82 , to protect an upper portion of the water level sensor  70 , and a lower receptacle  73  extending upwardly from the lower housing  81 , to protect a lower portion of the water level sensor  70 . Each of the receptacles  71  and  73  has a chamber structure. 
     The above-mentioned conventional steam generating device and the washing machine equipped with the same have the following problems. 
     Since the conventional steam generating device has a substantially rectangular shape having a small height L 1  and a large width L 2 , as shown in  FIG. 11 , it is difficult to install the steam generating device  50  in the washing machine. 
     In detail, this is because, although the steam generating device  50  is typically installed in an upper portion of the washing machine, namely, between the cabinet  10  and the tub  20 , the spacing t between the tub  20  and the steam generating device  50  is relatively small. 
     In the space defined between the cabinet  10  and tub  20 , a valve, hanging springs, etc. are also installed. For this reason, the space for installing the steam generating device  50  may be insufficient. As a result, it is difficult to install the steam generating device  50 . Furthermore, the steam generating device  50  may interfere with other elements of the washing machine when the washing machine is moved, so that the steam generating device  50  may be damaged. 
     Since the spacing between the cabinet  10  and the tub  20  is relatively small, they may strike against each other due to vibrations generated during operation of the washing machine. As a result, the cabinet  10  and tub  20  may be damaged. The repair or replacement of the damaged elements is also difficult. 
     In addition, it is required to achieve improvements in the amount of water used, energy efficiency, steam generating time, security, etc. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a steam generating device and a washing machine having the same that substantially obviate one or more problems due to limitations and disadvantages of the related art. 
     An object of the present invention is to provide a steam generating device, which can be more easily installed, and can prevent malfunction of a water level sensor, and a washing machine having the steam generating device. 
     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a steam generating device comprising: a lower housing for containing water, the lower housing receiving a heater and having a vertical length longer than a horizontal length; an upper housing including a steam chamber for containing steam generated as the water is heated; a water level sensor for sensing a water level of the water chamber; and a receptacle for covering the water level sensor, the receptacle including an opening for allowing water to be introduced into the receptacle. 
     The steam generating device may further comprise a barrier rib arranged at one side of the receptacle, to remove air bubbles introduced into the receptacle at the side of the receptacle. 
     The barrier rib may be arranged in a flow path of the air bubbles introduced into the receptacle. 
     The steam generating device may further comprise a vertical rib arranged to intersect the barrier rib while being spaced apart from the barrier rib. 
     More preferably, the steam chamber has a horizontal length longer than a horizontal length of the water chamber. 
     The steam generating device may further comprise a chamber arranged at the other side of the receptacle, to remove air bubbles into the receptacle at the other side of the receptacle. 
     The receptacle may include a long barrier wall arranged in a longitudinal direction of the water level sensor, and short barrier walls arranged at opposite sides of the long barrier wall, respectively, and connected to the upper housing. 
     Each of the short barrier walls may be formed with an opening for allowing water to be introduced into the receptacle. 
     At least one of the short barrier walls may be provided with a vertical rib for removing air bubbles introduced into the receptacle. 
     Preferably, the vertical rib is arranged to intersect the barrier rib while being spaced apart from the barrier rib. 
     More preferably, one of the short barrier walls may form a chamber for removing air bubbles introduced into the receptacle. 
     In another aspect of the present invention, a washing machine comprises: a body; a tub installed in the body; a drum rotatably installed in the tub; and a steam generating device including a lower housing for containing water, the lower housing receiving a heater and having a vertical length longer than a horizontal length, an upper housing including a steam chamber for containing steam generated as the water is heated, a water level sensor for sensing a water level of the water chamber, and a receptacle for covering the water level sensor, the receptacle including an opening for allowing water to be introduced into the receptacle. 
     In the washing machine, the receptacle may include a long barrier wall arranged in a longitudinal direction of the water level sensor, and short barrier walls arranged at opposite sides of the long barrier wall, respectively, and connected to the upper housing. 
     Each of the short barrier walls may be formed with an opening for allowing water to be introduced into the receptacle. 
     At least one of the short barrier walls may be provided with a vertical rib for removing air bubbles introduced into the receptacle. 
     The vertical rib may be arranged to intersect the barrier rib while being spaced apart from the barrier rib. 
     More preferably, one of the short barrier walls forms a chamber for removing air bubbles introduced into the receptacle. 
     Preferably, the steam chamber has a horizontal length longer than a horizontal length of the water chamber. 
     The washing machine may further comprise a separator for separating a flow path of steam outwardly discharged, from other regions. 
     The washing machine may further comprise a reverse flow preventing member arranged in at least one of a water supply line and a steam supply line, to prevent water or steam from flowing reversely. 
     The washing machine may further comprise a safety valve for outwardly discharging steam from a steam supply line when an excessive pressure is applied to the steam supply line. 
     In accordance with the above-described configuration, it is possible to easily install the steam generating device, and to avoid accumulation of foreign matter, and thus to prevent the water level sensor from malfunctioning. 
     It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIG. 1  is a schematic view illustrating an installed state of a steam generating device according to the present invention; 
         FIG. 2  is a perspective view illustrating the steam generating device shown in  FIG. 1 ; 
         FIG. 3  is a bottom view illustrating an upper housing shown in  FIG. 2 ; 
         FIG. 4  is a perspective view illustrating a part of a lower housing shown in  FIG. 2 ; 
         FIG. 5  is a sectional view corresponding to  FIG. 4 ; 
         FIG. 6  is a schematic view illustrating an installed state of a reverse flow preventing member according to the present invention; 
         FIG. 7  is a schematic view illustrating an installed state of a safety valve according to the present invention; 
         FIG. 8  is a perspective view illustrating a conventional drum washing machine; 
         FIG. 9  is a perspective view illustrating a steam generating device shown in  FIG. 8 ; 
         FIG. 10  is a partially-broken perspective view illustrating the steam generating device shown in  FIG. 8 ; and 
         FIG. 11  is a schematic view illustrating an installed state of the steam generating device shown in  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention now will be described more fully hereinafter with reference to the accompanying figures, in which embodiments of the invention are shown. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts, and no repeated description thereof will be given. 
       FIG. 1  is a schematic view illustrating an installed state of a steam generating device according to the present invention.  FIG. 2  is a perspective view illustrating the steam generating device shown in  FIG. 1 .  FIG. 3  is a bottom view illustrating an upper housing shown in  FIG. 2 .  FIG. 4  is a perspective view illustrating a part of a lower housing shown in  FIG. 2 . 
     Hereinafter, the principle of the steam generating device according to the present invention will be described with reference to  FIGS. 1 and 2 . 
     The steam generating device  100  of the present invention includes a lower housing  110  defined with a water chamber W, in which a heater  200  for heating water is installed. The steam generating device  100  also includes an upper housing  120  defined with a steam chamber S arranged over the water chamber W. The steam chamber S contains steam generated in accordance with the heating of water. 
     Water contained in the water chamber W is heated by the heater  200 , thereby generating steam. The generated steam is temporarily contained in the steam chamber S, and is then outwardly discharged from the steam chamber S through a steam discharge port  124  formed at the steam chamber S. 
     The water chamber W is configured to have a vertical length L 4  longer than a horizontal length L 5 . The heater  200  extends vertically in the water chamber W. As shown in  FIG. 1 , the vertical length of the water chamber W may substantially correspond to a length L 4   a , namely, the vertical extension length of the heater  200 . However, since it is preferred that water be contained in the water chamber W to a level higher than the top of the heater  200 , it is assumed, in the following description, that the vertical length of the water chamber W corresponds to “L 4 ”. 
     However, there is no contradiction or problem caused by this assumption because the difference between “L 4 ” and “L 4   a ” is relatively small, and the amount of water contained in the water chamber W to the level L 4   a  is a main portion of the total amount of water contained in the water chamber W. For the same reason, it is also assumed that the horizontal length of the water chamber W corresponds to the width of a portion of the water chamber W, in which the main portion of the total water amount is contained, namely, “L 5 ”. 
     Thus, it is possible to reduce the horizontal length L 5  of the water chamber W, as compared to conventional cases, while containing the same amount of water. Accordingly, it is possible to reduce the interference between the tub  20  and the steam generating device  100 . Through an experiment, it was found that, since the contact area between the steam and the water is large in accordance with the present invention, it is possible to reduce the amount of water used to generate the same amount of steam as the conventional cases, and the steam generating time, and thus to reduce the size of the steam generating device  100 . 
     Meanwhile, it is preferred that the horizontal length L 6  of the steam chamber S be relatively longer than the horizontal length L 5  of the water chamber W. That is, although it is possible to reduce the horizontal length L 6  of the steam chamber S, as compared to the conventional cases, it is preferred that the horizontal length L 6  of the steam chamber S be equal to or slightly shorter than those of the conventional cases. This is because a water supply port and a steam discharge port are typically formed at the steam chamber S, and a water level sensor, a temperature sensor, etc. are also mounted to the steam chamber S. 
     On the other hand, the vertical length L 4  of the water chamber W may be relatively longer than the horizontal length L 5 . As shown in  FIG. 1 , it is also preferred that the water chamber W be arranged substantially at a central portion of the steam chamber S. 
     Hereinafter, a concrete embodiment of the steam generating device  100  will be described with reference to  FIG. 2 . 
     As described above, the steam generating device  100  includes the lower housing  110  and upper housing  120 . The upper housing  120  has a horizontal length longer than the horizontal length of the lower housing  110 . 
     As shown in  FIG. 5 , the lower housing  110  includes a portion in which the heater  200  is mounted, which contains a main portion of the total amount of water in the water chamber W, and which has a vertical length longer than a horizontal length. This portion will be referred to as a “main portion  111 ”, for the convenience of description. The lower housing  110  also includes portions extending from the main portion  111  in opposite lateral directions, and connected to the upper housing  120 . These portions will be referred to as “connecting portions  112  and  114 ”, for the convenience of description. 
     It is preferred that the main portion of water in the water chamber W be present in the main portion  111  of the lower housing  110 , and the remaining small portion of water in the water chamber W be present in the connecting portions  112  and  114 . It is also preferred that the connecting portions  112  and  114  be inclined toward the main portion  111 . In accordance with this structure, it is possible to prevent foreign matter such as lime from being deposited over electrodes of a water level sensor  300  arranged in the connecting portions  112  and  114 . 
     Since the water chamber W is narrow in accordance with the present invention, the pressure and temperature of steam generated in the water chamber W is relatively high, as compared to conventional cases. To this end, it is preferred that the lower and upper housings  110  and  120  be made of a material capable of withstanding high pressure. In this regard, it is preferred that the lower and upper housings  110  and  120  be connected using vibration fusing, rather than thermal fusing. 
     Hereinafter, the upper housing  120  defined with the steam chamber S will be described with reference to  FIGS. 3 to 5 . 
     The water supply port  122  and steam discharge port  124  are formed at the upper housing  120 . Preferably, the housing  120  has a protruded portion, to form the water supply port  122  and steam discharge port  124  at the protruded portion. 
     The water level sensor  300  is arranged in the upper housing  120 . A temperature sensor  400  is also arranged in the upper housing  120 . It is preferred that the water level sensor  300  be arranged at a position spaced apart from the water supply port  122  by a certain distance, namely, at a position misaligned from a water supply direction of the water supply port  122 . 
     In this case, it is possible to prevent water splashed while being discharged from the water supply port  122  from coming into contact with the water level sensor  300 , and thus to prevent the water level sensor  300  from malfunctioning. 
     It is also preferred that the water level sensor  300  be arranged adjacent to an inner wall surface of the upper housing  120 , namely, be arranged over the connecting portion  114  of the lower housing  110 , rather than the main portion  111 . In other words, it is preferred that the water level sensor  300  be arranged to be spaced apart from the main portion  111  of the water chamber W by a certain distance. 
     In this case, it is possible to effectively prevent water splashed and air bubbles generated in an initial heating stage of the heater  200  from coming into direct contact with the water level sensor  300 , and thus to effectively prevent the water level sensor  300  from malfunctioning due to the splashed water and air bubbles. 
     Meanwhile, a receptacle  320  is mounted to the upper housing  120 , to protect the water level sensor  300 . The receptacle  320  is provided with openings  326  and  327  for allowing water to be introduced into the receptacle  320 . 
     As shown in  FIG. 4 , a barrier rib  370  is protruded from one side of the receptacle  320 , in order to remove air bubbles introduced into the receptacle  320  through the opening  326 . A chamber  390  is also defined in the receptacle  320 , opposite to the barrier rib  370 , in order to remove air bubbles introduced into the receptacle  320  through the opening  327 . 
     It is preferred that the barrier rib  370  be protruded into a flow path of air bubbles flowing toward the opening  326  of the receptacle  320 . 
     A vertical rib  380  may also be provided at one side of the receptacle  320 . The vertical rib  380  is protruded such that it intersects the barrier rib  370  while being spaced apart from the barrier rib  370  by a certain distance. 
     When the barrier rib  370  is arranged to intersect the vertical rib  380 , as described above, a curved flow path is defined in the vicinity of the opening  326 , through which air bubbles flow. Accordingly, air bubbles disappear gradually while passing through the flow path extending to the opening  326 . 
     The structure for removing air bubbles flowing toward the receptacle  320  will be described in detail with reference to  FIGS. 3 and 4 . For the convenience of description,  FIG. 4  illustrates a part of the receptacle  320  formed at the upper housing  120 . Also, in  FIG. 4 , the phantom lines and arrows indicate flows of air bubbles. 
     As shown in the drawings, the receptacle  320  may include barrier walls in accordance with the present invention. 
     In this case, it is preferred that the inner wall of the steam generating device  100  constitute a part of the barrier walls of the receptacle  320 . 
     For example, the barrier walls of the receptacle  320  may include a long barrier wall  324  arranged in parallel to the water level sensor  300 , to form a longitudinal surface of the receptacle  320 , and a pair of short barrier walls  322  and  323  each connected, at one end thereof, to the long barrier wall  324 , and connected, at the other end thereof, to the inner wall surface of the upper housing  120  such that the short barrier walls  322  and  323  form opposite lateral surfaces of the receptacle  320 , respectively. 
     Preferably, the long barrier wall  324  is arranged over the connecting portion  114  of the lower housing  110 . In particular, it is preferred that the long barrier wall  324  be arranged over a wall portion of the main portion  111  extending along the boundary between the main portion  111  and the connecting portion  114  of the water chamber W (substantially defined in the lower housing  110 ). 
     The first short barrier wall  322  may be arranged at one side of the heater  200 , whereas the second short barrier wall  323  may be arranged at the other side of the heater  200 . 
     Preferably, the first opening  326  is formed through the first short barrier wall  322  at the other end of the first short barrier wall  322 . Also, the second opening  327  is preferably formed through the second short barrier wall  323  at the other end of the second short barrier wall  323 . The vertical rib  380  is protruded from the first short barrier wall  322  in a direction perpendicular to the first short barrier wall  322 . 
     In this case, the barrier rib  370  is protruded from the inner wall surface of the upper housing  120  such that the barrier rib  370  intersects the vertical rib  380  while being spaced apart from the vertical rib  380  by a certain distance. 
     That is, as shown in  FIG. 4 , the barrier rib  370  is arranged at the side of the first opening  326 , together with the vertical rib  380 , to define a curved flow path of air bubbles. Accordingly, air bubbles disappear while passing through the curved flow path. As a result, there is no air bubble introduced into the first opening  326 . 
     Meanwhile, as described above, the chamber  390  may also be formed outside the second short barrier wall  323 , to remove air bubbles introduced into the second opening  327 . 
     Thus, at the side of the first short barrier wall  322 , the curved flow path is formed in accordance with the formation of the barrier rib  370  and vertical rib  380  such that air bubbles are removed while passing through the curved flow path. Also, at the side of the second short barrier wall  323 , the chamber  390  is formed such that air bubbles are removed when they are introduced into the chamber  390 , before being introduced into the second opening  327 . 
     Accordingly, it is possible to prevent air bubbles from being introduced into the receptacle  320  in opposite directions by the barrier rib  370  and chamber  390 , and thus to completely prevent the water level sensor  300  from malfunctioning due to air bubbles. 
     Meanwhile, the water level sensor  300  includes a common electrode  312 , a low-water-level electrode  314 , and a high-water-level electrode  316 . The high-water-level electrode  316  is spaced apart from the low-water-level electrode  314  by a certain distance. 
     For the water level sensor  300 , a standard product, which includes a common electrode  312 , a low-water-level electrode  314 , and a high-water-level electrode  316   a , is commercially available. Accordingly, a general water level sensor assembly, which has such a configuration, may be used in the present invention, without any modification. In this case, however, it is preferred that a separate high-water-level electrode  316  be used, in place of the high-water-level electrode  316   a  of the general water level sensor assembly. 
     In this case, It is also preferred that a high-water-level electrode receiver  318  is provided at a position spaced apart from the water level sensor  300 , to receive the high-water-level electrode  316 . For example, the high-water-level electrode receiver  318  may have a cylindrical barrier wall structure. In accordance with the provision of the high-water-level electrode receiver  318 , it is possible to prevent the water level sensor  300  from malfunctioning due to water drops attached between the low-water-level electrode  314  and the high-water-level electrode  316 . 
     As described above, the steam discharge port  124  is formed at the upper housing  120 , to discharge steam. A separator  420  is arranged at the steam discharge port  124 , in order to separate the flow path of steam discharged out of the steam discharge port  124  from other regions. 
     Water and air bubbles are severely splashed when the water is heated in the water chamber W, in particular, in an initial heating stage. The separator  420  prevents the splashed water from being introduced into the drum through the steam discharge port  124 . When the splashed water is introduced into the drum, spots may be formed on the laundry. The separator  420  avoids such a phenomenon. 
     The separator  420  may have various structures, as long as it has a hole communicating with the steam discharge port  124  therein, to receive steam from the steam discharge port  124 . For example, the separator  420  may have a barrier wall structure. In this case, it is preferred that the barrier wall structure has an opening  421  to receive steam. In particular, it is preferred that the barrier wall structure have a plurality of vertically-arranged openings  421  spaced apart from the steam discharge port  124  by a certain distance. 
     The barrier wall structure includes a first barrier wall  424  substantially facing the steam discharge port  124 , and a second barrier wall  422  spaced apart from the first barrier wall  424  while defining the opening  421 . Preferably, the first barrier wall  424  is arranged over the connecting portion  112  of the water chamber W, rather than the main portion  111  of the water chamber W. 
     An auxiliary separator  430 , for example, a barrier wall, may be arranged outside the separator  420 . Preferably, the barrier wall of the auxiliary separator  430  is arranged adjacent to the opening  421  of the separator  420 , without contacting the inner wall surface of the steam generating device  100 . 
     Meanwhile, water is supplied to the water chamber W via a water supply line including, for example, the water supply hose or water supply port  122 . Steam from the steam chamber S is discharged into the drum via a steam discharge line including, for example, the steam discharge port  124  and steam hose. 
     Preferably, a reverse flow preventing member is arranged in at least one of the water supply line and steam discharge line, to prevent water and steam from flowing reversely. For the reverse flow preventing member, various members may be used, as long as they have a reverse flow preventing function. For example, a one-way valve may be used for the reverse flow preventing member. 
     However, it is preferred that, for the reverse flow preventing member, a nozzle-shaped flexible member  600  be used, and a slit  610  be formed at a nozzle portion of the flexible member  600 , as shown in  FIG. 6 , because the reverse flow preventing member is arranged in the water supply hose, water supply port  122 , water discharge port  124 , or steam discharge hose, which has a relatively-small diameter. 
     Meanwhile, as shown in  FIG. 7 , a safety valve  700  may be arranged at a certain position of the steam discharge line. The safety valve  700  is automatically opened when the pressure of steam passing through the steam discharge line is higher than a predetermined level. The steam hose, which is designated by reference numeral “ 53 ” in FIG.  7 , may be branched to form a branch pipe  53   a , and the safety valve  700  may be arranged in the branch pipe  53   a.    
     When no steam is supplied to the drum due to a problem occurring in the steam supply line, an excessive pressure is applied to the steam supply line. In this case, the safety valve  700  is automatically opened to outwardly discharge steam from the steam supply line. 
     A draining member  115  is provided at the water chamber W, as shown in  FIG. 5 , to outwardly drain water from the water chamber W. An opening/closing member  113  is arranged at the draining member  115 , to open or close the draining member  115 . 
     That is, it is possible to outwardly drain water from the water chamber W by opening the opening/closing member  113 . As the steam generating device  100  is continuously used for a prolonged period of time, foreign matter such as lime is accumulated in the steam generating device  100 . In this case, the draining member  115  is opened to outwardly drain water from the water chamber W, and thus to discharge the accumulated foreign matter, together with the water. Accordingly, it is possible to avoid the accumulation of foreign matter. 
     The opening/closing member  113  may be a drain cap which can be manually opened or closed by the user or operator. Alternatively, the opening/closing member  113  is configured to be automatically opened or closed. For example, a solenoid valve may be used. Also, the opening/closing member  113  may be configured using a siphon principle. 
     The inner structure of the steam generating device according to the present invention including the barrier walls for the water level sensor, auxiliary barrier wall, separator, reverse flow preventing member, opening/closing member, etc. may be applied to general steam generating devices. 
     The steam generating device having the above-described configuration according to the present invention and the washing machine having the same provide the following effects. 
     First, it is possible to more easily install the steam generating device because the water chamber of the steam generating device has a vertical length shorter than a horizontal length. 
     Second, it is possible to enhance the performances of the steam generating device and washing machine because a desired amount of steam can be generated within a reduced time, using a reduced amount of water. 
     Third, an improvement in security is achieved because it is possible to efficiently prevent water and steam from flowing inversely, and the safety valve operates when an excessive pressure is generated due to a problem occurring in the steam supply line. 
     Fourth, it is possible to efficiently prevent the water level sensor from malfunctioning because a barrier rib and a chamber are formed at the sides of the short barrier walls of the receptacle, respectively, to remove air bubbles flowing toward the receptacle. 
     Fifth, it is possible to prevent water present in the steam generating device from entering the drum, and thus to prevent spots from being formed on laundry contained in the drum. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.