US20090293557A1

US20090293557A1 - Steam Generator and Washing Machine Having the Same

Info

Publication number: US20090293557A1
Application number: US11/791,121
Authority: US
Inventors: In Geun Ahn
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2005-08-29
Filing date: 2006-05-24
Publication date: 2009-12-03
Also published as: KR20070027104A; DE112006000092B4; KR101215347B1; DE112006000092T5; WO2007026989A1

Abstract

A steam generator having an improved structure to change water supplied into the steam generator into steam within a short period of time and a drum type washing machine having the same are disclosed. The washing machine includes a tub mounted in a cabinet, which constitutes the external appearance of the washing machine, for storing wash water, a drum rotatably mounted in the tub, and a steam generator mounted in the cabinet for supplying steam into the drum. The steam generator includes a case having a space for receiving a predetermined amount of water, the case being provided at one side thereof with an inlet port and an outlet port, a heater case disposed in the case such that the heater case communicates with the interior of the case, the heater case having an additional space, into which some of the water supplied into the case is introduced and a steam heater disposed in the heater case for heating the water introduced into the heater case so as to generate steam.

Description

TECHNICAL FIELD

The present invention relates to a drum type washing machine, and more particularly, to a drum type washing machine having a steam generator for rapidly, supplying steam into a drum.

BACKGROUND ART

Generally, washing machines are classified into a pulsator type washing machine, which performs a washing operation using water stream generated by the rotation of a plate-shaped pulsator, and a drum type washing machine, which performs a washing operation using falling of wash water and laundry and a friction force between the wash water and the laundry generated in a horizontally disposed drum by the rotation of the drum.
The drum type washing machine has been increasingly used since the drum type washing machine has advantages superior to the pulsator type washing machine in that the amount of wash water and detergent used during the washing operation is small, damage to the laundry is minimized, and the laundry is minimally tangled.
The structure of a conventional drum type washing machine will be described hereinafter with reference to FIG. 1.
As shown in FIG. 1, the conventional drum type washing machine includes a cabinet 10 constituting the external appearance of the drum type washing machine, a cylindrical tub 20 horizontally supported in the cabinet for storing wash water, a drum 30 rotatably mounted in the tub 20, the drum 30 being provided with through-holes, through which wash water and steam are introduced into the drum 30, a driving motor 40 for driving the drum 30, and at least one steam generator 50 for supplying steam into the drum 30.
At the front part of the cabinet 10 is formed a laundry opening 13, which communicates with the interior of the drum 30 such that laundry can be put into or removed from the drum 30 through the laundry opening 13. A door 11 is hingedly mounted to the cabinet 10 adjacent to the laundry opening 13 for opening and closing the laundry opening 13.
Along the inner circumference of the laundry opening 13 is mounted a gasket (not shown) for preventing hot air from leaking through the connection between the door 11 and the tub 20.
At one side of the drum type washing machine is provided a water supply valve 15, which is connected to an external water pipe (not shown) for supplying wash water into the tub 20 or supplying water into the steam generator 50.
The steam generator 50 is connected with the water supply valve 15 such that the water supplied from the water supply valve 15 can be introduced into the steam generator 50. The steam generator 50 heats the water supplied from the water supply valve 15 to generate steam, and supplies the generated steam into the drum 30.
As shown in FIG. 2, the steam generator 50 includes a case 51 constituting the external appearance of the steam generator, a water level detecting sensor 60 for detecting the water level of water supplied into the case 51, a heater 55 for heating the water supplied into the case 51, and a temperature detecting sensor 57 for detecting the temperature of the heated water.
The case 51 is provided at one side thereof with an inlet port 103 (see FIG. 1), which is connected to the water supply valve 15 (see FIG. 1) for allowing water to be introduced from the water supply valve 15 through the inlet port 103. The case 51 is also provided at one side thereof with an outlet port 105, through which steam generated in the case 51 is discharged to the drum 30 side.
Also, the steam generator 50 is provided at one side thereof with a steam supply pipe 53 (see FIG. 1), which is a passage for guiding and injecting the steam generated by the steam generator 50 into the drum 30 through the outlet port 105.
However, the conventional drum type washing machine with the above-stated construction has the following problem.
The amount of water supplied into the case 51 of the conventional steam generator 50 during the generation of steam is large, and therefore, time necessary to heat the water supplied into the case 51 into steam is increased. Consequently, power consumption is increased.

DISCLOSURE OF INVENTION

Technical Problem

An object of the present invention devised to solve the problem lies on a steam generator having an improved structure to change water supplied into the steam generator into steam within a short period of time and a drum type washing machine having the same.

Technical Solution

The object of the present invention can be achieved by providing a steam generator comprising: a case having a space for receiving a predetermined amount of water, the case being provided at one side thereof with an inlet port and an outlet port; a beater case disposed in the case such that the heater case communicates with the interior of the case, the heater case having an additional space, into which some of the water supplied into the case is introduced; and a steam heater disposed in the heater case for heating the water introduced into the heater case so as to generate steam.
Preferably, the heater case is mounted in the case such that the heater case is spaced apart from the bottom of the case.
Preferably, the heater case comprises: an introduction part having at least one introduction hole, through which some of the water supplied into the case is introduced into the heater case; and a discharge part having at least one discharge hole, through which steam generated in the heater case is discharged.
Preferably, the introduction part is formed at the lower surface of the heater case.
Preferably, the discharge part is formed at the upper surface of the heater case.
Preferably, the at least one introduction hole has a diameter less than that of the at least one discharge hole.
The steam generator may further comprise: a temperature detecting sensor disposed in the case for detecting the temperature of the steam discharged from the heater case.
The steam generator may further comprise: a water level detecting sensor disposed in the case for detecting the water level of the water received in the case.
In another aspect of the present invention, provided herein is a washing machine including a tub mounted in a cabinet, which constitutes the external appearance of the washing machine, for storing wash water, a drum rotatably mounted in the tub, and a steam generator mounted in the cabinet for supplying steam into the drum, wherein the steam generator comprises: a case having a space for receiving a predetermined amount of water, the case being provided at one side thereof with an inlet port and an outlet port; a heater case disposed in the case such that the heater case communicates with the interior of the case, the heater case having an additional space, into which some of the water supplied into the case is introduced; and a steam heater disposed in the heater case for heating the water introduced into the heater case so as to generate steam.
Preferably, the heater case is mounted in the case such that the heater case is spaced apart from the bottom of the case.
Preferably, the heater case comprises: an introduction part having at least one introduction hole, through which some of the water supplied into the case is introduced into the heater case; and a discharge part having at least one discharge hole, through which steam generated in the heater case is discharged.
Preferably, the introduction part is formed at the lower surface of the heater case.
Preferably, the discharge part is formed at the upper surface of the heater case.
Preferably, the at least one introduction hole has a diameter less than that of the at least one discharge hole.
The washing machine may further comprise: a temperature detecting sensor dispose d in the case for detecting the temperature of the steam discharged from the heater case.
The washing machine may further comprise: a water level detecting sensor disposed in the case for detecting the water level of the water received in the case.

Advantageous Effects

The steam generator with the above-stated construction has the following effects.
According to the present invention, the heater case, which is constructed such that a predetermined amount of water can be introduced into the heater case, is mounted in the case of the steam generator. Consequently, a small amount of water is instantaneously heated, and therefore, time necessary to generate steam is reduced.
As the time necessary to generate steam is reduced power consumption is decreased.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention.

In the drawings:

FIG. 1 is a perspective view schematically illustrating the structure of a conventional drum type washing machine.

FIG. 2 is a schematic view illustrating the internal structure of a conventional steam generator.

FIG. 3 is a longitudinal sectional view illustrating the structure of a drum type washing machine according to an embodiment of the present invention.

FIGS. 4 and 5 are schematic views illustrating the internal structure of a steam generator according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT 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.
FIG. 3 is a longitudinal sectional view illustrating the structure of a drum type washing machine according to an embodiment of the present invention, and FIGS. 4 and 5 are schematic views illustrating the internal structure of a steam generator according to an embodiment of the present invention.
As shown in FIG. 3, the washing machine according to the present invention includes a machine case 110, a tub 120, a drum 130, a steam supply unit, a temperature sensor 150, a circulating pump 160, a circulating channel 170, and a water level sensor (not shown) for detecting the water level of the wash water in the tub 120. In this embodiment, the washing machine is a drum type washing machine.
The machine case 110 constitutes the external appearance of the drum type washing machine. At the front part of the machine case 110 is formed a laundry opening 111.
A door 140 is mounted to the machine case 110 adjacent to the laundry opening 111 for opening and closing the laundry opening 111. At the inner circumference of the laundry opening 111 is mounted a gasket 112, which accomplishes sealing between the door 140 and the laundry opening 111.
Also, the machine case 110 is provided with a wash water supply pipe 113 for supplying wash water into the tub 120. On the pipe line of the wash water supply pipe 113 is mounted a detergent box 114.
The tub 120 is mounted in the machine case 110 in a supported state.
To the bottom of the tub 120 is connected a drainage channel 121 for draining wash water.
At the lower end of the tub 120 is mounted a wash water heater 122 for heating wash water supplied into the tub 120.
The drum 130 is rotatably mounted in the tub 120, and is disposed such that the open side of the drum 130 is directed to the laundry opening 111 of the machine case 110.
At the circumference of the drum 130 are formed a plurality of through-holes, through which wash water and steam supplied into the tub 120 are introduced into the drum 130.
The steam supply unit is constructed to supply a predetermined amount of steam into the tub 120 and/or the drum 130. In this embodiment, at least one steam supply unit is provided.
The circulating pump 160 is mounted on the drainage channel 121, which is connected to the tub 120, and is operated to pump the wash water supplied into the tub 120 such that the wash water can be circulated.
The circulating channel 170 is a pipe line which is connected to the circulating pump 160 for guiding the circulating movement of the wash water pumped by the circulating pump 160.
Preferably, the end of the circulating channel 170, i.e., the wash water discharging side, extends through the gasket 112 such that the end of the circulating channel 170 is directed to the inside wall of the drum 130. In this embodiment, the end of the circulating channel 170 is connected to the steam supply pipe 220 as shown in the accompanied drawings. Alternatively, the end of the circulating channel 170 may be connected to the inside of the drum 130 without being connected to the steam supply pipe 220.
The temperature sensor 150 is mounted at a predetermined position in the tub 120 for detecting the interior temperature of the tub 120.
The temperature detected by the temperature sensor 150 may be used to operate the steam supply unit and to control the wash water heater 122.
Meanwhile, unexplained reference numeral 180 indicates a water supply valve assembly 180 for selectively supplying wash water introduced from the outside to the detergent box 114 or the steam supply unit, reference numeral 181 indicates a wash water supply valve for controlling the supply of wash water into the tub 120 through the detergent box 114, and reference numeral 182 indicates a water-for-steam supply valve for controlling the supply of water into the steam supply unit.
The steam supply unit is constructed to evaporate water, using high-temperature hot air, into steam and to supply the steam into the tub 120 and/or the drum 130. The steam supply unit includes a steam generator (SG) 210 for generating high-temperature hot air to evaporate water into steam, a steam supply pipe 220, through which steam generated from the water evaporation by the steam generator 210 flows, and an injection nozzle 230 for injecting the steam flowing through the steam supply pipe 220 into the tub 120 and/or drum 130.
The injection nozzle 230 is constructed in the shape of a nozzle such that the steam can be smoothly injected through the nozzle. Preferably, the end of the injection nozzle 230, through which the steam is discharged, extends through the gasket 112 such that the end of the injection nozzle 230 is directed to the interior of the drum 130.
Hereinafter, the structure and the operation of the steam generator 210 according to an embodiment of the present invention will be described in more detail with reference to FIGS. 4 and 5. Arrows shown in FIG. 4 indicate discharge of steam generated in a heater case, and arrows shown in FIG. 5 indicate introduction of water into the heater case.
According to the present invention, the steam generator 210 includes a case 211, a heater case 300, a steam heater 213, a steam side temperature sensor 214, and a water level sensor 215.
The case 211 may be constructed in the shape of a rectangular box, which Institutes the external appearance of the steam generator 210 and forms a steam generation space.
The case 211 is provided at one side thereof with an inlet port 103 (see FIG. 1), which is connected to the water supply valve 182 for allowing water to be introduced into the case 211 through the inlet port 103. The case 211 is provided at the other side thereof with an outlet port 105, which is connected to the steam supply pipe 220 for allowing steam generated in the case 211 to be supplied into the drum 130 through the outlet port 105.
The heater case 300 is disposed in the case 211 such that the heater case 300 communicates with the interior of the case 211. The heater case 300 has an additional space, into which some of the water supplied into the case 211 is introduced.
The heater case 300 serves to heat the water introduced from the case 211 to generate steam and discharge the generated steam into the drum 130 through the case 211.
Preferably, the heater case 300 is mounted in the case 211 such that the heater case 300 is spaced apart from the bottom of the case 211. This construction is necessary to form an introduction part, which will be described below, at the bottom of the heater case 300.
Meanwhile, the steam heater 213 is mounted in the heater case 300. The steam heater 213 serves to heat water introduced into the heater case 300, through the heat generation of the steam heater 213, into steam.
The steam heater 213 may be constructed using a sheath heater. Although not shown in the drawings, a fuse is mounted in the steam heater 213 for interrupting the supply of power when the steam generator 210 is overheated so as to protect the steam generator 210.
Meanwhile, the heater case 300 comprises an upper case part 301 and a lower case part 303.
Preferably, an introduction part having at least one introduction hole 310, through which some of the water supplied into the case 211 is introduced into the heater case 300, is formed at the bottom of the lower case 303 of the heater case 300.
Also preferably, a discharge part having at least one discharge hole 330, through which the steam generated by the steam heater 213 in the heater case 300 is discharged, is formed at one side of the upper case 301 of the heater case 300.
More preferably, the at least one discharge hole 330 is located at the upper surface of the upper case 301.
According to the present invention, it is preferable that the diameter D1 of the at least one introduction hole 310 be less than the diameter D2 of the at least one discharge hole 330.
In this case, the speed of the water introduced through the at least one introduction hole 310 is less than that of the steam discharged through the at least one discharge hole 330.
Meanwhile, the steam side temperature sensor 214 is disposed in the case 211, and is electrically connected to a controller (not shown) of the washing machine. The steam side temperature sensor 214 serves to detect the interior temperature of the case 211 when the heat is generated from the steam heater 213.
Also, the water level sensor 215 is disposed in the case 211. The water level sensor 215 includes three electrodes, i.e., a common electrode 216, a long electrode 217, and a short electrode 218.
The water level sensor 215 serves to detect the water level of the water supplied into the case 211. The water level sensor 215 is electrically connected to the controller (not shown) of the washing machine, which controls all operations of the components of the washing machine, including the water supply valve assembly 180 and the steam heater 213.
The common electrode 216 and the long electrode 217 are formed such that the terminals of the common electrode 216 and the long electrode 217 are exposed approximately at the height set as the minimum water level of the water necessary to generate steam. The short electrode 218 is shorter than the common electrode 216 and the long electrode 217, and is formed such that the terminal of the short electrode 218 is exposed approximately at the height set as the maximum water level of the water necessary to generate steam.
Preferably, the height at which the terminals of the long electrode 217 and the common electrode 216 are exposed is a height at which the steam heater 213 is fully submerged in the water.
Hereinafter, the operation and effects of the steam generator with the above-stated construction will be described.
First, when electric power is supplied to the drum type washing machine, the controller (not shown) of the drum type washing machine controls the water supply valve 181 of the water supply valve assembly 180 to supply wash water into the tub 120 to a predetermined water level, controls the circulating pump 160 to circulate the wash water in the tub 120 to the upper part of the drum 130 along the outside of the tub 120, and controls the drum 130 to be rotated such that a laundry wetting process is carried out.
At this time, the controller controls the water-for-steam water supply valve 182 of the water supply valve assembly 180 to supply a predetermined amount of water into the case 211 of the steam generator 210.
After the water is supplied into the case 211, the water level of the water supplied into the case 211 is detected by the steam side water level sensor 215, as previously described.
Meanwhile, some of the water supplied into the case 211 is introduced into the heater case 300 through the introduction holes 310 formed at the lower case 303 of the heater case 300.
At this time, the water introduced into the heater case 300 is heated by the steam heater 213 such that the water is changed into steam.
Meanwhile, the interior pressure of the heater case 300 is higher than the pressure outside the heater case 300, i.e., the interior pressure of the case 211, due to the heat generated from the steam heater 213, and therefore, the steam generated in the heater case 300 is discharged into the case 211.
Since the interior pressure of the heater case 300 is higher than that of the case 211 while the steam is generated in the heater case 300, and is then discharged from the heater case 300, no water is introduced into the heater case 300 through the introduction holes 310.
Subsequently, the steam discharged into the case 211 is guided along the steam supply pipe 220, which is connected to the case 211 and the drum 130, and is then discharged into the drum 130, in which laundry is received such that the steam is directed to the laundry.
After the steam generated in the heater case 300 is discharged for a predetermined period of time, the water level of water in the heater case 300 is lowered and the interior pressure of the heater case 300 becomes lower than the pressure outside the heater case 300, i.e., the interior pressure of the case 211.
At this time, the discharge of steam is interrupted and water is reintroduced into the heater case 300 through the introduction holes 310 formed at the lower side of the heater case 300.
After a predetermined amount of water is introduced into the heater case 300, the water is heated by the steam heater 213. As a result, the interior temperature and the interior pressure of the heater case 300 are increased, and therefore, steam is discharged again.
The steam generator 210 repeatedly performs the above-described procedure, whereby the steam is supplied into the drum 130.
While the laundry is wetted by the resupply of water into the tub 120, the rotation of the drum 130, and the operation of the circulating pump 160, as described above, high-temperature steam is rapidly injected into the drum 130 by the steam generator 210 according to the present invention, whereby the interior of the drum 130 is controlled to reach a predetermined temperature which can achieve the greatest washing efficiency of the washing machine.
The laundry wetting process and the steam supply process through the steam generator 210 are carried out until the temperature detected by the temperature sensor 150 reaches a target temperature.
When the temperature detected by the temperature sensor 150 reaches a target temperature, the supply of steam through the steam generator 210 is interrupted and the wash water supply valve 181 is controlled to supply water into the tub 120 to the predetermined water level. After that, the drum 130 is alternately rotated in the clockwise and counterclockwise directions such that a post washing process is carried out according to a predetermined program.
During the post washing process, the wash water heater 122 may be used to heat the wash water in the tub 120 to a predetermined temperature, or the circulating pump 160 may be operated by predetermined periods of time to circulate the wash water.
After the post washing process is completed selected operations, such as a rinsing operation and a spin-drying operation, are successively carried out.
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 invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

INDUSTRIAL APPLICABILITY

According to the present invention, a small amount of water is instantaneously heated in the heater case, which is disposed in the case of the steam generator. As a result, time necessary to generate steam is reduced and therefore, power consumption resulting from the operation of the steam generator is decreased. Consequently, the present invention has considerably high industrial applicability.

Claims

1. A steam generator comprising:

a case having a space for receiving a predetermined amount of water, the case being provided at one side thereof with an inlet port and an outlet port;

a heater case disposed in the case such that the heater case communicates with the interior of the case, the heater case having an additional space, into which some of the water supplied into the case is introduced; and

a steam heater disposed in the heater case for heating the water introduced into the heater case so as to generate steam.

2. The steam generator according to claim 1, wherein the heater case is mounted in the case such that the heater case is spaced apart from the bottom of the case.

3. The steam generator according to claim 1, wherein the heater case comprises:

an introduction part having at least one introduction hole, through which some of the water supplied into the case is introduced into the heater case; and

a discharge part having at least one discharge hole, through which steam generated in the heater case is discharged.

4. The steam generator according to claim 3, wherein the introduction part is formed at the lower surface of the heater case.

5. The steam generator according to claim 3, wherein the discharge part is formed at the upper surface of the heater case.

6. The steam generator according to claim 3, wherein the at least one introduction hole has a diameter less than that of the at least one discharge hole.

7. The steam generator according to claim 1, further comprising:

a temperature detecting sensor disposed in the case for detecting the temperature of the steam discharged from the heater case.

8. The steam generator according to claim 1, further comprising:

a water level detecting sensor disposed in the case for detecting the water level of the water received in the case.

9. A washing machine including a tub mounted in a cabinet, which constitutes the external appearance of the washing machine, for storing wash water, a drum rotatably mounted in the tub, and a steam generator mounted in the cabinet for supplying steam into the drum, wherein the steam generator comprises:

a steam heater disposed in the heater case for heating the water introduced into the heater case to generate steam.

10. The washing machine according to claim 9, wherein the heater case is mounted in the case such that the heater case is spaced apart from the bottom of the case.

11. The washing machine according to claim 9, wherein the heater case comprises:

12. The washing machine according to claim 11, wherein the introduction part is formed at the lower surface of the heater case.

13. The washing machine according to claim 11, wherein the discharge part is formed at the upper surface of the heater case.

14. The washing machine according to claim 11, wherein the at least one introduction hole has a diameter less than that of the at least one discharge hole.

15. The washing machine according to claim 9, further comprising:

16. The washing machine according to claim 9, further comprising: