EP1913860B1

EP1913860B1 - Dishwasher with condenser in the door

Info

Publication number: EP1913860B1
Application number: EP07110352A
Authority: EP
Inventors: Jung Youp Han; Sang Heon Yoon; Tae Hee Lee
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2006-10-17
Filing date: 2007-06-15
Publication date: 2010-09-08
Anticipated expiration: 2027-06-15
Also published as: EP1913860A2; CN101164491A; EP1913860A3; DE602007009009D1; US20080087307A1; CN101164491B

Description

The present invention relates to a dishwasher, and more particularly, to a dryer of a dishwasher, which can rapidly condense steam generated during a drying cycle. Such a dishwasher is known from CH-A-683 819 .
A dishwasher is a machine that sprays wash liquid through spray nozzles under high pressure to remove food or residue left on dishes, or any items in the dishwasher.
The dishwasher includes a tub defining a washing chamber and a sump mounted on a bottom of the tub to contain the wash liquid. A washing pump is installed inside the sump to pump the wash liquid to the spray nozzles. The wash liquid is sprayed under high pressure through spray holes formed at the ends of the spray nozzles. The wash liquid, sprayed under high pressure, collides against the surfaces of the dishes, so that food residue and impurities on the dishes fall down to the bottom of the tub.
High-temperature steam can be applied in a dishwasher using a ventilation-type drying method or a circulation-type drying method.
According to the ventilation-type drying method, a drying fan discharges moist air out of the tub. However, a dishwasher using the ventilation-type drying method has a drawback in that high-temperature, high-humidity air is directly discharged out of the tub causing discomfort to a user near the dishwasher. Also, due to the direct discharge of the high-temperature, high-humidity air, the user or child may get scalded by the discharge.
During the discharge of the high-temperature, high-humidity air, steam may be condensed around a steam outlet and flow to the floor causing the floor to become wet. Further, there is a danger that a user may slide or fall down onto the floor due to the condensed water collecting on the floor. Moreover, mildew may form from the condensed water collected on the floor.
According to the circulation-type drying method, steam is condensed by a condenser provided inside the tub and is again introduced into the tub. A dishwasher using the circulation-type drying method has a drawback in that steam is not condensed sufficiently or efficiently because the condenser is small in size. Due to the small-sized condenser, it takes a long time to dry the dishes and an additional condenser may be required.
Accordingly, a dishwasher that substantially obviates one or more of the aforementioned problems due to limitations and disadvantages of the related art is highly desirable.
An object of the present invention is to provide a dishwasher having an improved condenser that rapidly condenses steam.
Another object of the present invention is to provide a dishwasher that shortens a drying time by rapidly condensing steam discharged during a dry cycle.
A further object of the present invention is to provide a dishwasher that rapidly condenses steam, so that a user does not feel uncomfortable or get scalded by the discharge of the dishwasher.
A still further object of the present invention is to provide a dishwasher that has an improved condenser, so that additional condensers are not required.
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 the claims, 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, there is provided a dishwasher, according to the appended independent claim 1.
According to embodiments of the present invention, the steam discharged during the dry cycle can be rapidly condensed.
Also, the drying time can be shortened because the steam discharged during the drying cycle is rapidly cooled.
The user does not feel uncomfortable because the steam discharged during the drying cycle is rapidly cooled.
In addition, scalds associated with steam discharge can be eliminated because the steam discharged during the drying cycle is rapidly cooled.
Further, an additional condenser is not required because a portion of the door may perform a function of the condenser.
Furthermore, condensation may not occur near the steam outlet and thus condensed water is not discharged into an area surrounding the dishwasher, such as the floor. Therefore, it is possible to prevent condensed water from forming on floor space adjacent to the dishwasher, and consequently, prevent resulting accidents.
Moreover, it is possible to prevent mildew from forming at a corner due to the condensed water falling down to the floor.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, and should not be construed as limiting the scope of the claims.
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. The drawings illustrate embodiment(s) of the invention and together with the description serve to explain principles of the invention. In the drawings:
Fig. 1 is a side sectional view of a dishwasher according to an embodiment of the present invention;
Fig. 2 is an enlarged view of a portion A of Fig. 1;
Fig. 3 is a front view of a door liner of a dishwasher according to an embodiment of the present invention;
Fig. 4 is a front view illustrating an exemplary condensation process of the dishwasher according to an embodiment of the present invention; and
Fig. 5 is a graph of the condensation process of Fig. 4.
Reference will now be made in detail to the various 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.
Fig. 1 is a side sectional view of a dishwasher according to an embodiment of the present invention, and Fig. 2 is an enlarged view of a portion A of Fig. 1.
Referring to Figs. 1 and 2, the dishwasher 100 includes a cabinet 101 defining an outer frame 102, a tub 110 protected by the cabinet and forming a washing chamber, a door 270 rotatably mounted at a front side of the tub 110 to open/close the washing chamber, and a sump 170 disposed at a bottom center portion of the tub 110 to contain wash liquid.
The dishwasher 100 includes a washing pump 180 installed inside the sump 170 to pump wash liquid under high pressure, and a motor 190 connected to a shaft of the washing pump 180 to drive the washing pump 180.
The door 270 includes a door cover 272 and a door liner 271. The door cover 272 defines a front appearance or exterior portion of the dishwasher. The door liner 271 is connected to a rear side of the door cover 272. A condenser is interposed between the door cover 272 and the door liner 271, which will be described later.
The washing pump 180 may be controlled to stop its operation when an opening of the door 270 is detected during a high-temperature wash cycle. Also, the washing pump 180 may be controlled to restart its operation after a predetermined time elapses when a closing of the door 270 is detected.
The dishwasher 100 includes a water guide 140, a bottom nozzle 160, a middle nozzle 150, and a top nozzle 155. The water guide 140 provides a path through which wash liquid pumped by the washing pump 180 flows. The bottom nozzle 160 is disposed on the bottom of the tub 110 above the sump 170. The bottom nozzle 160 is configured to spray wash liquid upwards. The middle nozzle 150 is branched from a predetermined portion 151 of the water guide 140 and is disposed near a center portion of the tub 110. The top nozzle 155 is disposed near a ceiling of the tub 110 to spray wash liquid vertically downwards. Each of the nozzles are configured to spray washing liquid toward items in racks.
The condenser 200 is disposed between the door cover 272 and the door liner 271. A fan assembly is connected to an upper portion of the condenser 200 to suck or draw out steam from within the tub 110. Specifically, the fan assembly includes a fan 260 for drawing out or sucking out steam from within the tub 110 and discharging steam to the condenser 200. The fan assembly further includes a fan housing 250 for receiving and housing the fan 260. A discharge duct 290 is connected to another side of the fan housing 250 so as to discharge steam.
The condenser 200 is tightly attached to a rear side or interior side of the door cover 272, so that outside air and steam inside the condenser 200 are heat-exchanged with each other through the door cover 272. That is, air outside the door 270 and steam inside the condenser 200 are heat-exchanged with each other by heat conduction through walls of the door cover 272 and the condenser 200. A front side of the condenser 200 may be opened. The opened front side of the condenser 200 may be covered and tightly sealed by the door cover 272, such that heat is achieved rapidly. That is, the door cover 272 may form a portion of the condenser 200.
Specifically, the front side of the door cover 272 forms an exterior portion of the dishwasher. The front side of the door cover 272 is exposed to the outside. The rear surface of the door cover 272 is tightly contacted with the front surface of the condenser 200. The rear surface of the door cover 272 may be exposed to high-temperature steam flowing through the condenser 200. Therefore, high-temperature steam inside the condenser 200 is condensed through heat exchange through the door cover 272 with external air, which may be air of room-temperature.
Since the door cover 272 of the door 270 is tightly contacted with one side of the condenser 200 or forms a portion of the condenser 200, additional condensation components are not required, and thus the condenser structure can be simplified.
An operation of the dishwasher 100 illustrated in Fig. 1 will be described below.
The user opens the door 270 of the dishwasher 100 and pulls an upper rack 120 and/or a lower rack 130 out of the washing chamber. The user places items, such as dishes, on the upper and/or lower racks 120 and 130. Then, the user closes the door 270 and operates the dishwasher 100 by switching it on.
When the dishwasher 100 performs a wash cycle, wash liquid is supplied to the sump 170. After the supply of the wash liquid is completed, the motor 190 begins to operate. As an impeller of the motor 190 is rotating, the wash liquid is alternately pumped to the bottom nozzle 160 or the water guide 140. The bottom nozzle 160 is configured to spray washing liquid when it is pumped to the bottom nozzle 160 and ready to be released. The impeller of the motor 190 is provided inside the washing pump 180 connected to the shaft of the motor 190.
The wash liquid pumped to the water guide 140 flows to the top nozzle 155 and the middle nozzle 150 and is sprayed into the washing chamber. Any items in the upper and/or lower racks 120 and 130 are washed by the sprayed wash liquid.
However, when the door 270 is opened during a high-temperature wash cycle, the washing pump 180 restarts its operation after a predetermined time elapses so as to prevent the wash liquid contained in the sump 170 from overflowing due to the expansion of cold air introduced into the tub 110.
In other words, when the sprayed high-temperature wash liquid comes in contact with low-temperature air, the wash liquid contained in the sump 170 overflows due to air expansion. In order to prevent this phenomenon, the washing pump 180 is configured to stop its operation upon detecting an opening/closing of the door 270 or any such motion during the high-temperature wash cycle. Then, the washing pump 180 restarts its operation after a predetermined time elapses.
The top nozzle 155 is configured to spray the wash liquid vertically downwards and the middle nozzle 150 sprays the wash liquid vertically upwards, so that the dishes received in the upper rack 120 are washed by the wash liquid from the top and middle nozzles.
In addition, the bottom nozzle 160 is configured to spray the wash liquid vertically upwards, so that the dishes received in the lower rack 130 are washed. Spray holes can also be formed at the bottom of the middle nozzle 150. In this case, because the middle nozzle 150 sprays the wash liquid upwards and downwards, the upper surfaces of the dishes received in the lower rack 130 can also be washed, while the lower surfaces of the dishes received in the upper rack 120 are washed.
The dirty wash liquid collected in the sump 170 during the wash cycle is filtered by a filter (not shown). When the dishwasher 100 finishes the wash cycle and begins a discharge cycle, a discharge pump (not shown) pumps the filtered wash liquid out of the dishwasher 100.
After the wash liquid is discharged, the dishwasher 100 is configured to perform a rinse cycle. That is, clean wash liquid is supplied to the sump 170 through an inlet and is sprayed through the nozzles 150 and 160 similarly to the spraying of wash liquid provided in the wash cycle, so that the dishes are rinsed by the sprayed clean wash liquid.
After the rinse cycle, the dishwasher 100 performs a drying cycle to dry the dishes and then the aforementioned dishwashing operation is finished.
Fig. 3 is a front view of a door liner of a dishwasher according to an embodiment of the present invention, and Fig. 4 is a front view illustrating a condensation process of the dishwasher according to the embodiment of the present invention.
Referring to Figs. 3 and 4, a fan assembly, a condenser 200, and an outside air guide 280 are provided in the front of a door liner 271 forming a rear surface of the door. The fan assembly sucks or draws out steam from inside the tub 110. A condenser 200 is connected to one side of the fan assembly to condense the sucked or drawn steam. The external air guide 280 is connected to another side of the fan assembly such that air that is external to the tub is drawn in and provided to the fan assembly.
The fan assembly includes a fan 260 for sucking or drawing out the steam and discharging the steam, and a fan housing 250 for receiving and housing the fan 260.
A hole is formed in the rear surface of the fan housing 250, and a hole is formed in the door liner 271. The hole of the door liner 271 is substantially the same size as the hole of the fan housing 250. The position of the hole of the door liner 271 may correspond to the position of the hole of the fan housing 250. A blower cover, which will be described later, may be installed in the holes. An actuator, which will be described later, moves the blower cover forward and backward to selectively open/close the holes.
A steam outlet 252 is formed in a portion of a front surface of the fan housing 250, and an outside air inlet 251 is formed in another portion of the fan housing 250. In addition, a mixed gas outlet 254 is formed in yet another portion of the fan housing 250. The condensed steam and the outside air sucked through the outside air guide 280 are discharged through the discharge duct into, for example, an indoor space.
Specifically, the condenser 200 includes an inlet through which the steam is introduced, and an outlet through which the condensed steam is discharged. At least one flow guide 201 is formed inside the condenser 200 to guide a downward flow of the steam. A discharge hole 203 is formed at the bottom or lowermost portion of the condenser 200. In addition, a discharge hole, corresponding to the discharge hole 203, is formed in the door liner 271.
The steam outlet 252 is connected to the inlet of the condenser 200 and the mixed gas outlet 254 is connected to the outlet of the condenser 200. The discharge duct 290 extends down the door 270 and has a discharge opening 291 whose cross section is wider at the end of the discharge duct 290 than at an upper portion of the discharge duct 290. An outside air inlet 281 is formed at the end of the outside air guide 280 and is located under the door, such that the indoor air is introduced through the outside air inlet 281.
During a drying cycle, the fan 260 received in the fan housing 250 rotates and the blower cover is withdrawn, so that the holes of the door liner 271 and the fan housing 250 are opened. Therefore, high-temperature, high-humidity steam existing inside the tub 110 is introduced through the holes into the fan housing 250. The introduced steam is discharged from the steam outlet 252 into the condenser 200.
In addition, the steam introduced through the inlet of the condenser 200 descends along the flow guide 201. The descending steam in the condenser 200 is cooled by the heat conduction with external air. External air may refer to air outside the tub or air outside the dishwasher. Condensed water in the steam descending along the flow guide 201 is concentrated in the discharge hole 203 and is again introduced into the tub 110. On the other hand, steam that becomes gaseous after the condensation is configured to ascend along flow guide 202 and is introduced through a mixed gas inlet 253 into the fan housing 250.
Simultaneously, indoor air is sucked or drawn in via an external air inlet 281 and passes through the outside air guide 280 to the outside air inlet 251 of the fan assembly. External air may refer to air outside the dishwasher. Air drawn from outside the dishwasher may be air drawn from an indoor environment, such as air in a home or building. The external air discharged to the outside air inlet 251 is introduced into the fan housing 250 and is mixed with the steam discharged from the mixed gas inlet 253. The mixture of the steam and the indoor air is again condensed while descending along the discharge duct 290. That is, the mixed gas is condensed primarily in the condenser 200 and secondarily in the discharge duct 290.
Meanwhile, the pressure of the mixed gas descending along the discharge duct 290 is decreased while the mixed gas passes through the discharge opening 291. In other words, the pressure of the gas decreases as the cross sectional area of the discharge opening 291 increases into an expanding shape. As a result, the mixture or gas discharged through the discharge opening 291 maintains a gaseous state throughout the discharge duct 290. Thus, the condensation phenomenon does not occur around the discharge opening 291.
It is preferable that the fan assembly includes a double-suction centrifugal fan because the fan 260 must suck or draw out steam from within the tub 110 and external air through the outside air guide 280.
In addition, it is preferable that the air introduced through the flow guide 201 into the condenser 200 is sufficiently condensed. Therefore, it is preferable that the flow formed by the flow guide 201 is formed in a curved shape. For example, the flow guide 201 may include a substantially S-shape or form.
Although the steam inside the tub and the indoor air are mixed in the inside of the fan housing 250, they can also be mixed in an area outside of the fan housing 250.
Fig. 5 is a graph of an exemplary condensation process in accordance with an embodiment of the present invention.
Referring to Fig. 5, reference numeral 300 represents a state in which the steam inside the tub is introduced into the condenser 200 via the steam outlet 252. (See Fig. 4)
Specifically, the steam introduced into the condenser 200 reaches a dew point and is condensed into condensed water, while flowing through a flow path formed inside the condenser 200, as indicated by a reference numeral 301. A reference numeral 302 represents a state in which uncondensed steam arrives near the mixed gas inlet 253. As illustrated in Fig. 5, although a large amount of the high-temperature steam has been condensed in the condenser 200, some steam still remains in a state substantially near the dew point.
Therefore, the remaining steam is mixed with the external air, which may be indoor air at room temperature. In other words, external air existing in the state indicated by a reference numeral 303 is sucked in through the outside air guide 280 and discharged to the condenser 200. Then, the outside air is mixed with the steam 302 and introduced into the fan housing 250. The mixed gas reaches a state indicated by reference number 304. That is, the mixed gas reaches a state substantially below the dew point. Therefore, although the mixed gas is discharged from the discharge opening 291, dew condensation around the discharge opening 291 can be minimized. In addition, the mixture or gas discharged from the discharge opening 291 is able to maintain its gaseous state via the expanding shape of the discharge opening 291.
It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the scope of the invention. Thus, it is intended that the claims cover the modifications and variations provided they come within the scope of the claims.

Claims

A dishwasher (100), the dishwasher (100) comprising a tub (110) defining a washing chamber and a door (270) for opening/closing the tub (110);
a condenser (200) provided within the door (270) to condense steam discharged from the tub (110);
a fan assembly connected to the condenser (200), the fan assembly including a steam outlet through which steam inside the tub (110) is discharged into the condenser (200); characterized in that an inlet and an outlet of the condenser (200) are connected to the fan assembly and the dishwasher (100) further comprises
an air guide (280) for supplying air external to the tub to the fan assembly for mixing the steam passed through the condenser (200) and the external air in the fan assembly.
The dishwasher according to claim 1, wherein the door (270) comprises
a door liner (271) exposed to an interior of the tub (110), and
a door cover (272), provided at a front side of the door liner (271), to form an exterior portion of the dishwasher (100),
wherein the condenser (200) is disposed between the door liner (271) and the door cover (272).
The dishwasher according to claim 2, further comprising at least one hole formed in a lower portion of the condenser (200) and the door liner (271) such that water formed from the condensed steam is introduced into the tub (110).
The dishwasher according to claim 3, wherein the lower portion of the condenser (200) slopes downward.
The dishwasher according to any of claims 2 to 4, wherein the condenser (200) is sealed to a surface of the door cover (272).
The dishwasher according to any of claims 2 to 5, wherein a front side of the condenser (200) is opened, the opened front side being closed by the door cover (272) and being sealed to the door cover (272).
The dishwasher according to any of claims 2 to 6, wherein steam introduced into the condenser (200) is heat-exchanged with the external air by heat conduction through the door cover (272).
The dishwasher according to any of claims 1 to 7, further comprising a discharge duct (290) provided at another side of the fan assembly to discharge a mixture of the external air and the steam.
The dishwasher according to claim 8, wherein the steam discharged through the discharge duct is configured to be condensed primarily in the condenser (200) and configured to be condensed secondarily while passing through the discharge duct (290).
The dishwasher according to claim 8, wherein the discharge duct (290) has an outlet having an expanding shape.
The dishwasher according to any of claims I to 10, wherein the fan assembly comprises:
a fan housing (250);

a fan housed in the fan housing (250); and

a blower cover provided at a side of the fan housing (250) to provide selective communication between the tub (100) and the fan housing (250).
The dishwasher according to claim 11, wherein the condenser (200) comprises an outlet through which condensed steam is discharged, the outlet being connected to the fan housing (250).
The dishwasher according to claim 11 or 12, wherein the fan (260) comprises a double-suction centrifugal fan.
The dishwasher according to any of claims 1 to 13, further comprising at least one flow guide (201) provided inside the condenser (200) to guide a flow of the steam.
The dishwasher according to any of claims 8 to 14, wherein the outside air guide (280) comprises an opening exposed to external air.