Abstract:
A dish washer which includes a steam generator. The dish washer, for example, may comprise a tub to provide a room for dishes for washing, a sump to hold water for supplying to the tub for the washing; a steam generator to generate steam, a first tube (or a steam tube) to provide a passage for the steam from the steam generator to the tub, and a valve to release the steam or water from the steam generator according to a pressure.

Description:
This application claims the benefit of Korean Patent Application No. 10-2007-0096711, filed on Sep. 21, 2007 which is hereby incorporated by reference in its entirety as if fully set forth herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is related to a dish washer which includes a steam generator. 
     2. Discussion of the Related Art 
     Generally, dish washers are used for removing dirty and remaining food from food dishes and eating utensils (hereinafter, collectively referred to as dishes) by injecting wash water onto the dishes at a high pressure. 
     Such a dish washer includes a tub forming a cleaning chamber and a sump disposed at a lower portion of the tub for storing wash water. A pump is installed in the sump to pump the wash water to an injection nozzle connected to the sump. The wash water arrived at the injection nozzle is injected through a nozzle hole formed in an end of the injection nozzle at a high pressure. Two injection nozzles can be disposed at upper and lower portions of the tub, respectively, and the upper injection nozzle can be connected to the sump by a water guide. 
     SUMMARY OF THE INVENTION 
     A dish washer according to the present invention washes dishes using water and steam. 
     One embodiment of a dish washer according to the present invention may comprise, a tub to provide a room for dishes for washing, a sump to hold water for supplying to the tub for the washing, a steam generator to generate steam, and a first tube (or a steam tube) to provide a passage for the steam from the steam generator to the tub. 
     The dish washer may include a valve to release the steam or water out of the steam generator when the first tube is blocked. 
     The valve may operate according to a pressure. For instance, the valve may operate to open when an internal pressure of the steam generator or the first tube reaches a predetermined pressure. 
     Instead of the valve, a membrane may be used. The membrane may be broken at a predetermined pressure to allow the steam or the water inside of the steam generator to be discharged. 
     The dish washer may comprise a second tube (or a auxiliary steam tube) to provide a passage for the steam or the water to be released out. 
     The second tube may be configured to release the steam or the water to an inside of the tub. 
     The dish washer may further comprise an air guide to allow outside air to flow into the tub and the second tube may be configured to release the steam or the water through the air guide. 
     The second tube may be further configured to release the steam or the water to the inside of the tube through the sump. 
     Alternatively, the second tube may be configured to release the steam or the water to an outside of the dish washer, rather than the inside of the tub. 
     The second tube may be connected to a lower portion of the steam generator. Further, the second tube may be connected to a portion lower than a water level sensor of the steam generator. 
     The second tube may be connected to the steam generator at a portion lower than where the first tube is connected. 
     The dish washer may comprise a sensor to sense that the first tube is blocked and a controller to control the valve according the sensed result. 
     The sensor may include a pressure sensor and the controller may control the valve to open at a predetermined pressure. 
     Another embodiment of a dish washer according to the present invention may comprise a tub to provide a room for dishes for washing, a sump to hold water for supplying to the tub for the washing, a steam generator to generate steam, a first tube to provide a passage for the steam from the steam generator to the tub, a sensor to sense that the first tub is blocked, and a controller to control the steam generator according the sensed result. 
     The sensor may include a pressure sensor and the controller may switch off the steam generator at a predetermined pressure. 
     The controller may switch off a heater of the steam generator upon sensing that the first tub is blocked. 
    
    
     
       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  shows a first embodiment of a dish washer according to the present invention; 
         FIG. 2  shows a longitudinal section of the dish washer of  FIG. 1 ; 
         FIG. 3  shows a second embodiment of a dish washer according to the present invention; and 
         FIG. 4  shows a third embodiment of a dish washer according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     Referring to  FIG. 1 , a dish washer includes a case  1  forming the external appearance of the dish washer, the case  1  being opened at the front thereof, a door  2  for opening and closing the open front of the case  1 , and a control panel  3  provided at the upper side of the door  2  for displaying and controlling the operation of the dish washer. 
     The control panel  3  includes a power switch  5  for turning on/off the dish washer, a door grip  4  used for a user to open and close the door  2 , an input device  7  for allowing the user to input various commands, a display device  8  for displaying the operation state of the dish washer, and a steam discharge port  6  for discharging high-temperature air out of the dish washer. 
       FIG. 2  shows a longitudinal section of the dish washer of  FIG. 1 . 
     To describe the internal structure of the dish washer with reference to  FIG. 2 , the dish washer includes a tub  18  mounted in the case  1  for defining a space where dishes are washed and a sump  16  mounted at the bottom of the tub  18  for collecting wash water to wash the dishes and filtering garbage out of the wash water such that the filtered water can be sprayed to the dishes again. 
     In the sump  16  is mounted a predetermined pump (not shown), such as an impeller, for pumping out the wash water stored in the sump  16 . A heater (not shown) is also mounted in the sump  16  for heating the wash water stored in the sump  16 . Consequently, detergent may be easily dissolved in the wash water, and food waste on the dishes may be easily soaked by the heated wash water, thereby improving washing efficiency. 
     In the tub  18  are mounted racks in which dishes are received. In this embodiment, the racks include an upper rack  11  and a lower rack  12 . However, the racks may be configured in various manners depending upon the size and capacity of the dish washer. 
     In the tub  18  are also mounted spray arms  14  and  15  for spraying wash water toward the upper rack  11  and the lower rack  12  and a spray arm  24  for spraying wash water from the upper part to the lower part of the tub  18 . In the tub  18 , at one side thereof, may be provided a wash water tube  19  for supplying the wash water stored in the sump  16  to the spray arms  14  and  24 , located at the upper part of the tub  18 , by the predetermined pump (not shown), such as the impeller. 
     Also, an introduction hole  17  may be formed at the bottom of the tub  18 , i.e., at the top of the sump  16 . Consequently, the wash water containing garbage, used to wash dishes, falls to the bottom of the tub  18 , and is then collected into the sump  16  through the introduction hole  17 . The wash water collected in the sump  16  may be supplied again to the spray arms  14 ,  15 , and  24  by the predetermined pump, such as the impeller. At this time, the sump  16  may be constructed in a structure to filter the garbage from the wash water. 
     Meanwhile, the dish washer may further include a steam generator  100  for heating water received in the steam generator  100  to generate steam to be supplied into the tub  18 , a steam tube  110  for guiding the steam generated by the steam generator  100  such that the steam is supplied into the tub  18 , and at least one nozzle  120  for spraying the steam supplied from the steam tube  110  into the tub  18 . 
     The steam generator  100  is located below the tub  18 . As a result, the steam generated by the steam generator  100  can be smoothly supplied into the tub  18 . This is because steam is lighter than air, and therefore, the steam exhibits a rising property. In the dish washer, however, the location of the steam generator  100  is not particularly restricted. Example, the steam generator  100  may be located at the side of the tub  18 . 
     Specifically, the steam generator  100  includes a case  102  for receiving water, a heater  104  for heating the water received in the case  102 , a water level sensor  106  for sensing the level of the water received in the case  102 , and a fuse (not shown) for preventing the overheating of the heater  104 . 
     The water level sensor  106  senses a low water level and a high water level. The low water level is set to prevent the overheating of the heater  104  in the steam generator  100 , thereby securing the safety of the dish washer. The low water level is set to be higher than the installation position of the heater  104 . On the other hand, the high water level is set to prevent the water supplied into the steam generator  100  from overflowing the steam generator  100 . Consequently, when the high water level is sensed by the water level sensor  106  during the supply of water into the case  102 , the supply of water is interrupted. On the other hand, when the lower water level is sensed by the water level sensor  106  during the generation of steam by the heater  104 , the operation of the heater  104  is stopped, and water is supplied into the case  102 . 
     Meanwhile, the dish washer may further include an air guide  200  mounted between the case  1  and the tub  18 , i.e., at the outside of the tub  18 , for achieving the communication between external air and the air in the tub  18 . 
     Consequently, an atmospheric state is maintained in the tub  18  through the air guide  200 , and therefore, it is possible to prevent the internal pressure of the tub  18  from rising due to steam or high-temperature air. This is to prevent breakage of the tub  18 , which may occur when the internal pressure of the tub  18  rises, and, to prevent a user from being injured due to high internal pressure of the tub  18  when the user opens the door  2  during the operation of the dish washer. 
     Specifically, the air guide  200  includes an air suction port  201  for suctioning external air, an opening  202  for achieving the communication between the tub  18  and the air guide  200 , and an air tube  203  for achieving the communication between the air suction port  201  and the opening  202 . 
     Noise in the tub  18  is easily transmitted to the outside through the air suction port  201  via the opening  202 . Such leakage of noise may be prevented by the provision of a baffle mounted at a predetermined position of the air tube  203 . That is, the direction of the air tube  203  is changed at least once by the baffle  204 , with the result that it is possible to effectively prevent the leakage of the noise in the tub  18  to the outside. 
     Meanwhile, the air guide  200  may further include a water supply tube  33  and a drainage tube  25 , which are separated from the air tube  203 . That is, water supplied from an external water source, such as a faucet, is supplied into the sump  16  through the water supply tube  33  provided in the air guide  200 , and the water discharged from the sump  16  is drained to the outside through the drainage tube  25  provided in the air guide  200 . 
     At this time, a water supply pipe  30  connected between the water supply tube  33  and the external water source branches into the water supply tube  33  and the steam generator  100  such that water can be supplied to the steam generator  100  as well as to the water supply tube  33 . At predetermined position of the water supply pipe  30  are mounted a first valve  40  for controlling the amount of water supplied to the water supply tube  33  and a second valve  41  for controlling the amount of water supplied to the steam generator  100 . 
     Consequently, when the first valve  40  is opened, water from the external water source is supplied into the sump  16  through the water supply tube  33 . On the other hand, when the second valve  41  is opened, water from the external water source is supplied into the steam generator  110 . 
     In the water supply tube  33  may be also mounted a water level sensor  34 , by which an appropriate amount of wash water is introduced into the dish washer to prevent excessive supply of water. 
     At a predetermined position of a connection pipe  22  connected between the drainage tube  25  and the sump  16  is mounted a drainage pump  50 . Consequently, the wash water in the sump  16  is drained to the outside through the drainage tube  25  by the operation of the drainage pump  50 . 
     The discharge tube  25  is formed in a reverse U shape. Also, the discharge tube  25  extends through a position higher than the water level in the sump  16 . This is because, if the drainage tube  25  is located lower than the sump  16 , wash water newly supplied into the sump  16  may be drained through the drainage tube  25  due to the height difference between the drainage pump  25  and the sump  16  and the pressure difference caused by the height difference, even after the operation of the drainage pump  50 . 
     This embodiment is constructed in a structure in which water from the external water source is supplied into the sump  16  through the water supply tube  33  of the air guide  200 , and the wash water in the sump  16  is drained to the outside through the drainage tube  25  of the air guide  200 , to which, however, the present invention is not limited. For example, water from the external water source may be directly supplied into the sump  16  not through the air guide  200 , or the water in the sump  16  may be drained directly to the outside. 
     Hereinafter, the operation of the dish washer will be described briefly with reference to  FIGS. 1 and 2 . 
     First, when dishwashing is required, a user puts dishes into the racks  11  and  12 , and closes the door  2 . 
     Subsequently, the user manipulates the input device to make a desired operation of the dish washer to be performed. As a result, the operation of the dish washer is performed while the operation state of the dish washer is displayed on the display device  8 . 
     To describe the operation of the dish washer according to the flow sequence of the wash water flowing in the tub  18 , on the other hand, the wash water, sprayed from the spray arms  14 ,  15 , and  24 , washes the dishes placed in the racks  11  and  12 , falls downward, and is collected into the sump  16  through the introduction hole  17 . 
     In the sump  16  is mounted a predetermined pump, such as an impeller. The pump pumps out the wash water such that the wash water is resupplied to the respective spray arms  14 ,  15 , and  24 . 
     Also, the dish washer may carry out a washing process using steam according to a user&#39;s selection. To carry out the washing process using steam, steam generated by the steam generator  100  is supplied into the tub  18  through the steam tube  110  and the nozzle  120 . 
     In the dish washer, therefore, it is possible to expect the improvement of washing efficiency of the dish washer which can be further obtained by high-temperature and high-humidity properties of the steam. For example, when the dishes are washed using the steam and the wash water, food waste fixed to the dishes is soaked by the steam, and the food waste is easily removed from the dishes by the high-pressure wash water. 
     Meanwhile, the waste separated from the dishes during the dishwashing using the steam may be introduced into the nozzle  120  and the steam tube  110 , with the result that the nozzle  120  and the steam tub  110  may be clogged. When the nozzle  120  and the steam tub  110  are clogged by the garbage introduced into the nozzle  120  and the steam tube  110 , the steam, generated by the steam generator  110 , is not discharged from the steam generator  110 , with the result that the internal pressure of the steam generator  100  increases, whereby the steam generator  100  may break or explode. 
     For this reason, it is preferable to prevent the internal pressure of the steam generator  100  from excessively rising at the time when the nozzle  120  or the steam tub  110  is clogged. 
     To this end, the dish washer may further include an auxiliary tube  130  for preventing the internal pressure of the steam generator  100  from exceeding a predetermined pressure when the steam tube  110  is clogged. Here, the predetermined pressure may be a maximum pressure at which the steam generator  100  does not break or explode. 
     The steam generated by the steam generator  100  or the water stored in the steam generator  100  is discharged out of the steam generator  100  through the auxiliary tube  130 , whereby it is possible to prevent the internal pressure of the steam generator  100  from exceeding the predetermined pressure. That is, when the steam tube  110  is clogged, the steam generated by the steam generator  100  is discharged out of the steam generator  100  through the auxiliary tube  130 , with the result that the internal pressure of the steam generator  100  does not rise. Alternatively, when the steam tube  110  is clogged, the water stored in the steam generator  100  is discharged out of the steam generator  100  through the auxiliary tube  130  due to the rising pressure, with the result that the internal pressure of the steam generator  100  does not rise. 
     On the other hand, the auxiliary tube  130  may be provided to discharge the steam generated by the steam generator  100  or the water stored in the steam generator  100  out of the dish washer. Consequently, when the steam tube  110  is clogged, the steam generated by the steam generator  100  or the water stored in the steam generator  100  may be discharged out of the dish washer through the auxiliary tube  130 . In this case, it is possible for a user to recognize the clogging of the steam tube  110  from the steam or the water discharged out of the dish washer and to take a measure to solve the clogging of the steam tube  110 . 
     As shown in  FIG. 2 , the auxiliary tube  130  is configured to discharge the steam generated by the steam generator  100  or the water stored in the steam generator  100  into the tub  18 . For example, one side of the auxiliary tube  130  is connected to the steam generator  100 , and the other side of the auxiliary tube  130  is connected to a predetermined position of the tub  18 . 
     In a case in which the auxiliary tube  130  is configured to discharge the steam generated by the steam generator  100  into the tub  18  when the steam tube  110  is clogged, as described above, it is possible to prevent the internal pressure of the steam generator  100  from rising, and, in addition, to smoothly carry out the dishwashing process using the steam. Generally, the steam is generated at the time when the steam is needed during the dishwashing process of the dish washer. This is because, when the steam generated by the steam generator  100  is discharged into the tub  18  although the steam tube  110  is clogged, it is possible to smoothly carry out the dishwashing process using the steam. Of course, the discharge of the steam into the tub  18  has the effect of reducing the waste of resources as compared with the drainage of the steam to the outside. 
     Also, in a case in which the auxiliary tube  130  is configured to discharge the water stored in the steam generator  100  into the tub  18  when the steam tube  110  is clogged, the water discharged into the tub  18  may be drained to the outside through the drainage tube  25  of the dish washer, which is preferred. 
     Meanwhile, it is preferred to discharge the steam into the tub  18  through the auxiliary tube  130  only when the steam tube  110  is clogged. This is because, when the steam tube  110  is not clogged, it is preferred to supply the steam into the tub  18  through the steam tube  110 . 
     To this end, the dish washer may include a sensor (not shown) for sensing whether the steam tube  110  is clogged or not, a valve  140  mounted at a predetermined position of the auxiliary tube  130  for selectively opening and closing the auxiliary tube  130 , and a controller (not show) for controlling the valve  140  to be opened when the clogging of the steam tube  110  is sensed by the sensor. 
     Consequently, since the auxiliary tube  130  is closed by the valve  140  when the steam tube  110  is not clogged, the steam generated by the steam generator  100  can be supplied into the tub  18  only through the steam tube  110 . On the other hand, when the steam tube  110  is clogged, the valve  140  is opened by controller, and therefore, the steam generated by the steam generator  100  is discharged into the tub  18  through the auxiliary tube  130 . 
     Since the steam tube  110  is clogged when the internal pressure of the steam generator  100  rises, the water stored in the steam generator  100  may also discharged into the tub  18  through the auxiliary tube  130  when the valve  140  is opened by the controller. 
     The kind of the sensor is not particularly restricted as long as the sensor can sense whether the steam tube  110  is clogged or not. For example, the sensor may be a heat sensor and may be mounted at the end of the steam tube  110 . In this case, the sensor can sense whether the steam tube  110  is clogged or not by sensing whether steam is discharged through the steam tube  110 . When the steam is discharged through the steam tube  110 , the heat sensor can sense heat from the steam; however, when the steam is not discharged, the heat sensor cannot sense heat. 
     The sensor is a pressure sensor for sensing the internal pressure of the steam generator  100 . When the steam tube  110  is clogged, with the result that the steam generated by the steam generator  100  cannot be discharged into the tub  18 , the internal pressure of the steam generator  100  greatly rises. At this time, the pressure sensor can sense whether the steam tube  110  is clogged or not by sensing the internal pressure of the steam generator  100 . 
     When the pressure sensed by the pressure sensor exceeds a predetermined pressure, the controller determines that the steam tube  110  is clogged and controls the valve  140  to be opened such that the steam is discharged into the tub  18  through the auxiliary tube  130 . 
     Here, the predetermined pressure is a pressure indicating that the steam tube  110  is clogged. The internal pressure of the steam generator  100  may vary. Therefore, the predetermined pressure indicates that the internal pressure of the steam generator  100  rises to such an extent that it is recognized that the steam tube  110  is clogged. 
       FIG. 3  is a longitudinal sectional view showing a second embodiment of a dish washer. 
     This embodiment is identical to the previous embodiment except an auxiliary tube  150 . Therefore, components of this embodiment identical to those of the previous embodiment are denoted by the same reference numerals, and a detailed description thereof will not be given. 
     Referring to  FIG. 3 , the auxiliary tube  150  according to this embodiment may be configured to discharge steam generated by the steam generator  100  or water stored in the steam generator  100  into the tub  18  through the sump  16  when the steam tube  110  is clogged. For example, one side of the auxiliary tube  150  may be connected to a predetermined position of the steam generator  100 , and the other side of the auxiliary tube  150  may be connected to a predetermined position of the sump  16 . 
     Since the sump  16  is configured to receive wash water and supply the wash water into the tub  18 , the steam generated by the steam generator  100  or the water stored in the steam generator  100  may be discharge into the sump  16  through the auxiliary tube  150  and then supplied into the tub  18 . 
     In this embodiment, the sensor, the valve  140 , and the controller may be provided to discharge the steam generated by the steam generator  100  into the tub  18  through the auxiliary tube  150  only when the steam tube  110  is clogged, as in the previous embodiment shown in  FIG. 2 . 
     Meanwhile, the other end of the auxiliary tube  150  is connected to a position of the sump  16  higher than the water level of the wash water received in the sump  16 . This is because, when the other end of the auxiliary tube  150  is connected to a position of the sump  16  lower than the water level of the wash water received in the sump  16 , the wash water may be introduced into the auxiliary tube  150 . 
     As shown in  FIG. 3 , the other end of the auxiliary tube  150  is connected to a position adjacent to the introduction hole  17 , formed at one side of the top of the sump  16 . In this case, the steam discharged through the auxiliary tube  150  may be supplied directly into the tub  18  through the introduction hole  17 . 
       FIG. 4  is a longitudinal sectional view schematically showing a third embodiment of a dish washer. 
     This embodiment is identical to the previous embodiment shown in  FIG. 2  except an auxiliary tube  160 . Therefore, components of this embodiment identical to those of the previous embodiment are denoted by the same reference numerals, and a detailed description thereof will not be given. 
     Referring to  FIG. 4 , the auxiliary tube  160  according to this embodiment may be configured to discharge steam generated by the steam generator  100  or water stored in the steam generator  100  into the tub  18  through the air guide  200  when the steam tube  110  is clogged. For example, one side of the auxiliary tube  150  may be connected to a predetermined position of the steam generator  100 , and the other side of the auxiliary tube  150  may be connected to a predetermined position of the air guide  200 . 
     Since the air guide  200  is mounted between the case  1  and the tub  18 , i.e., at the outside of the tub  18 , for achieving the communication between external air and the air in the tub  18 , the steam generated by the steam generator  100  or the water stored in the steam generator  100  may be discharge into the air guide  200  through the auxiliary tube  160  and then supplied into the tub  18 . 
     It is possible to easily manufacture the dish washer when the auxiliary tube  160  is connected to the air guide  200  than when the auxiliary tube  160  is connected to the tub  18  and the sump  16 . This is because the air guide  200  is manufactured as a module, which is attached to the outside of the tub  18 , and therefore, a first connection part  205 , to which the auxiliary tube  160  is connected, is easily formed at a predetermined position of the air guide  200 . 
     Also, the tub  18  and the sump  16  are spaces in which wash water flows, and therefore, there is a possibility that the wash water is introduced into the auxiliary tube  160 . However, the air guide  200  is a space in which air flows, and therefore, there is no possibility that the wash water is introduced into the auxiliary tube  160 , which is preferred. 
     Specifically, the air guide  200  includes the air suction port  201 , the opening  202 , and the air tube  203 . The first connection part  205  may be located at a position adjacent to any one of the air suction port  201 , the opening  202 , and the air tube  203 . The first connection part  205  is located at a position adjacent to the opening  202 . In this case, the steam, discharged into the air guide  200  through the auxiliary tube  160 , may be supplied directly into the tub through the opening  202 . 
     In this embodiment, the sensor, the valve, and the controller may be provided to discharge the steam generated by the steam generator  100  into the tub  18  through the auxiliary tube  160  only when the steam tube  110  is clogged, as in the previous embodiment shown in  FIG. 2 . 
     On the other hand, a second connection part  181 , connected between the auxiliary tube  160  and the steam generator  100 , may be mounted at the bottom of the steam generator  100 . Consequently, it is possible to discharge the steam or the water into the tub  18  through the auxiliary tube  160  only when the steam tube  110  is clogged, without the provision of the sensor, the valve, and the controller. This is because steam exhibits a rising property. 
     In this case, a third connection part  184 , connected between the steam tube  110  and the steam generator  100 , may be located at a position higher than the second connection part  181 . That is, it is preferred for the second connection part  181  to be located at a position lower than the third connection part  184 . Consequently, when the steam tube  110  is not clogged, the steam generated by the steam generator  100  is supplied into the tub  18  through the steam tube  110 , and, when the steam tube  110  is clogged, the steam generated by the steam generator  100  is supplied into the tub  18  through the auxiliary tube  160 . 
     The second connection part  181  is located at a position lower than the low water level of the steam generator  100 . In this case, an introduction part  183  of the auxiliary tube  160  is filled with water to a water level  182  corresponding to the water level of the steam generator  100 . Consequently, when the steam tube  110  is not clogged, the steam generated by the steam generator  100  or the water stored in the steam generator  100  is not discharged to the auxiliary tube  160 . On the other hand, when the steam tube  110  is clogged, the internal pressure of the steam generator  100  increases, and therefore, the steam or the water is discharged through the introduction part  183  of the auxiliary tube  160 . 
     That is, when the steam tube  110  is not clogged, the steam generated by the steam generator  100  is discharged only through the steam tube  110 , and, when the steam tube  110  is clogged, the steam generated by the steam generator  100  is discharged through the auxiliary tube  160 . 
     The air guide  200  is located at a position higher than the steam generator  100 . Consequently, when the internal pressure of the steam generator  100  does not exceed a predetermined pressure, the water stored in the steam generator  100  is not discharged into the tub  18  through the auxiliary tube  160 , and, only when the internal pressure of the steam generator  100  exceeds the predetermined pressure, the water is discharged into the tub  18  through the auxiliary tube  160 . 
     Therefore, the simple structure as described above has the same effect as the structure including the sensor, the valve, and the controller as shown in  FIG. 2 . 
     Meanwhile, the above-described structure is also applicable to the embodiments shown in  FIGS. 2 and 3 , i.e., the structure in which the auxiliary tube is connected to the sump  16  or the tub  18 . 
     As apparent from the above description, the idea of the present invention is to prevent the internal pressure of the steam generator from increasing when the steam tube is clogged. However, the idea of the present invention is not limited to the embodiments previously described. That is, 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. 
     For example, the dish washer may include a sensor for sensing the clogging of the steam tube and a controller for stopping the operation of the steam generator when the clogging of the steam tube is sensed by the sensor. 
     This is to stop the operation of the steam generator, such that no more steam is generated by the steam generator, thereby preventing the internal pressure of the steam generator from increasing, unlike the previously described method of discharging the steam generated by the steam generator, when the steam tube is clogged, thereby preventing the internal pressure of the steam generator from increasing. 
     The sensor may be a pressure sensor for sensing the internal pressure of the steam generator, and the controller may control the steam generator to be stopped when the pressure sensed by the pressure sensor exceeds a predetermined pressure. More specifically, when the pressure sensed by the pressure sensor exceeds the predetermined pressure, the controller determines that the steam tube is clogged and controls the heater in the steam generator to be turned off such that no more steam is generated by the steam generator.