EP2543305B1 - Dishwasher - Google Patents

Description

The present invention relates to a dishwasher with a fresh water tank. Such dishwashers are used both in the household and in the catering sector use.

There are known dishwashers, which have a fresh water tank, in which fresh water is kept, which is heated by a heater to a certain temperature and then used for a rinse cycle in a washing container in the dishwasher. For energetic optimization of the heating of the fresh water beats the DE 30 21 746 A1 before that the fresh water tank is fed via a heat exchanger, which is thermally conductively connected to the washing container. Now, if fresh water is passed through the heat exchanger for a second rinse, while a first rinse with heated rinse water is performed, then the heat exchanger removes heat from the heated rinse water in the washing and warms the fresh water. The heat exchanger is in this case designed as a pipe coil, and the fresh water tank is thermally insulated from the washing provided.

Furthermore, from the DE 39 00 617 A1 a method for heat recovery in a dishwasher is known, in which the wastewater from the washing container is temporarily stored and then brought with subsequent inflowing fresh water in heat exchange when the fresh water is to be heated according to the program.

Finally, the reveals DE 102 13 810 A1 a dishwasher with a condensation device for the vapors generated in the rinsing tank, and means for heating the water exiting the condensation device and supplied to the rinsing container, wherein these devices utilize heat for heating other components of the dishwasher.

The DE 10 2008 022890 A1 describes a household appliance that allows reuse of process heat through a flow heat exchanger to save energy.

In view of rising energy prices, there is a continuing need for further energy optimization in dishwashers. Against this background, an object of the present invention is to provide a dishwasher, with which the amount of energy necessary for heating the rinse water can be reduced.

Therefore, a dishwasher is proposed, which has a fresh water tank, which can be filled with fresh water, and a drain pipe for the discharge of waste water from a washing container of the dishwasher, wherein the drain pipe is passed through the fresh water tank. The fresh water can extract heat from the heated wastewater. The drain pipe is designed as a wave pipe and the washing is heat-conducting connected to the fresh water tank.

The discharged through the drain pipe wastewater is heated. The fresh water kept ready in the fresh water tank for a subsequent rinse in the fresh water tank extracts heat from the heated waste water, so that less energy has to be applied for heating this fresh water. In this case, a "fresh water tank" is a container in which unused rinse water, ie rinse water which has not yet been supplied to the rinse tank, is kept in stock. However, it is possible that the water supplied to the fresh water tank may contain additional substances such as e.g. Descaling or cleaning agents are added.

The drainage pipe can be formed, for example, as a drain hose. Under a "hose" is here to understand a flexible line, in particular made of plastic. Such hoses are easy and inexpensive to manufacture and can be easily mounted in the fresh water tank due to their flexibility.

The drain pipe is designed as a shaft pipe. A corrugated pipe has a large surface area, which enables rapid heat transfer and high heat exchanger efficiency. The outer diameter of the shaft pipe can be in the troughs, for example, 10-16 mm. At the wave crests, the outer diameter of the shaft pipe, for example, be 18-22 mm. The distance between adjacent wave crests of the wave pipeline may be, for example, 2-5 mm.

The drainage pipe can be meandering as a coil through the fresh water tank. This increases the surface area of the drainage pipe in the fresh water tank, allowing for quick heat transfer and higher efficiency of the heat exchanger.

The rinse tank is thermally conductive connected to the fresh water tank. Thus, the fresh water tank acts as a total heat exchanger and removes heat from the heated rinse water in the washing.

The drainage pipe can be designed for the integral connection of a drain pump of the dishwasher with a sanitation facility. In this case, no further pipe sections between the drain pump and the sanitation are to be provided in addition to the drain pipe. Thus, no additional sealing points or coupling pieces must be provided in or on the drainage pipe. Furthermore, thus the drainage pipe can be checked for tightness before installation in the fresh water tank.

The drain pipe can be performed on the input side through the bottom of the fresh water tank. Thus, a short distance to the drain pump for pumping out the rinse water from the washing is guaranteed.

The drainage pipe can be performed on the input side of a lower part of the fresh water tank substantially perpendicular to an upper part of the fresh water tank. Thus, the input side higher pressure is optimally used by the drain pump for pumping out the rinse water from the washing.

Further advantageous embodiments and aspects of the invention are the subject of the dependent claims and the embodiments of the invention described below. Furthermore, the invention will be explained in more detail by means of preferred embodiments with reference to the attached figures.

Fig. 1

eine schematische Seitenansicht einer Geschirrspülmaschine; und

Fig. 2

eine schematische Schnittansicht durch einen Frischwasserbehälter der Geschirrspülmaschine.

It shows:

Fig. 1

a schematic side view of a dishwasher; and

Fig. 2

a schematic sectional view through a fresh water tank of the dishwasher.

In the figures, the same or functionally identical elements have been given the same reference numerals, unless stated otherwise.

In the Fig. 1 is a schematic side view of a dishwasher 1 according to an embodiment shown. The dishwasher 1 comprises a washing container 2 which can be closed watertight by a door 3. The rinsing container 2 and the door 3 thus form a rinsing chamber 4 for rinsing dishes. In this case, the washing compartment 2 can be arranged in the interior of a housing 5. The washing container 2 can be made, for example, of stainless steel with a thickness of about 0.4 mm. The door 3 is in Fig. 1 shown in their closed position. By pivoting about a provided at the lower end of the door 3 pivot axis, the door 3 can be opened to the front, and items can be set in the dishwasher 1 or removed therefrom.

At the upper end of the door 3, an operating device 6 and a display device 7 may be provided, which are operatively connected to a control device 8. In the control device 8 more washing programs are stored, which can be selected and started with the aid of the operating device 6. The display device 7 displays status information, e.g. about the selected wash program or the expiration of the same.

The dishwasher 1 further comprises an upper dish rack 9 and a lower dish rack 10 into which dishes to be washed can be set. The baskets 9 and 10 may be arranged on extension rails, which are attached to opposite, extending in the depth direction side walls of the washing compartment 2.

As a rinsing liquid S for rinsing the items to be washed, fresh water FW is used, which can be taken up by a water supply device 11, for example a water supply network, and conducted into the rinsing chamber 4. For this purpose, the fresh water FW is first passed into a fresh water tank 12 and collected. The collected fresh water FW can be introduced as a rinsing liquor via an inlet valve 13 and a water inlet 14 into the rinsing chamber 4. This inlet valve 13 may be formed, for example, as an electrically switchable valve. The flushing water S introduced into the flushing chamber 4 collects in a sump or pot-shaped collecting tank 15 which is provided at the bottom of the flushing tank 2.

Below the collecting container 15, a circulating pump 16 is provided. On the input side, the circulation pump 16 is connected to the collecting container 15, and on the output side, the circulation pump 16 is connected to a spraying device. The spraying device comprises an upper rotatable spray arm 17 and a lower rotatable spray arm 18. When the circulating pump 16 is switched on, the rinsing water S enters the spray arms 17 and 18 and is expelled therefrom. As a result, the spray arms 17 and 18 are set in rotation and the rinse water S is distributed in the washing chamber 4 and on the dishes provided therein. Subsequently, the rinse water S flows back into the collecting container 15th

After completion of a wash program, the circulation pump 16 is turned off, and the collected in the sump 15 rinse water is pumped as waste AW by means of a drain pump 19. The sewage AW is pumped from the drain pump 19 via a drain pipe 20 to a sanitation facility 21. The sanitation device 21 may be, for example, a sewer pipe of a building-side water installation.

Fig. 2 schematically shows a side view of the fresh water tank 12 and an exemplary course of the drainage pipe 20 through the fresh water tank 12. The fresh water tank 12 may be, for example cuboid, with a height of about 50 cm, a width of about 50 cm and a depth of about 3 cm. The fresh water tank 12 may be made of plastic, such as polypropylene, or made of metal. Fresh water FW is passed through an upper opening 22 in the fresh water tank 12 and can be supplied through a lower opening 23 via the valve 13 to the washing compartment 2. In the example shown, the drainage pipe 20 runs from the drain pump 19 initially to a location below the fresh water tank 12, enters the bottom (or a lower wall) 26 of the fresh water tank 12 in this, is meandering through the fresh water tank 12 out, at the bottom 26 of the fresh water tank 12 again comes out of this, and is connected through an opening in the housing 5 with the sanitation 21. The fresh water FW collected in the fresh water tank 12 typically has a temperature of 5 ° to 25 ° C. This can be heated by a heater, not shown, depending on the washing program to a temperature of for example 50 to 75 ° C. The heater can also be mounted in the fresh water tank 12. Accordingly, the wastewater AW guided through the drainage pipe 20 also has a temperature of, for example, 50 ° to 75 ° C. when flowing off. The effluent AW guided in the drainage pipe 20 through the fresh water tank 12 heats the fresh water FW kept ready in the fresh water tank 12 for the next rinse cycle, so that the fresh water tank 12 acts as a heat exchanger. Thus, the heater for heating the fresh water FW can be operated at a lower power, so that energy can be saved.

In the illustrated example, the drainage pipe 20 rises in the fresh water tank 12 on the input side substantially perpendicularly (for example, at an angle less than 20 ° to the vertical) from the bottom, ie from a lower part of the fresh water tank 12, to near the ceiling, so an upper part of the fresh water tank 12. Thus, the input side higher pressure is optimally used by the drain pump 19 in the wastewater AW. From the highest point within the fresh water tank 12, the drainage pipe 20 is meandering in several loops back down toward the bottom 26 of the fresh water tank 12 out. Thus, an increase in the area of the drainage pipe 20 is achieved, which causes a higher efficiency of the heat exchanger. The drainage pipe 20 can by several, in the representation of Fig. 2 only indicated in the upper left corner, clips 24 are fixed to a wall of the fresh water tank 12. The drain pipe 20 may also be passed through the fresh water tank 12 in another way. For example, the drainage pipe 20 may be guided meandering from the bottom to the ceiling of the fresh water tank 12.

In a preferred embodiment, the drain pipe 20 is formed as a corrugated hose. Under a corrugated tube in this case is to be understood a tube whose wall has a waveform. In this way, an enlargement of the Surface of the drain pipe 20 is reached, which causes a rapid heat transfer and a higher efficiency of the heat exchanger. The wave period may be, for example, 2 to 5 mm. A wave period of about 3 mm is preferred. In the troughs, that is, the portions of the corrugated drainage pipe 20 having the smallest outer diameter, the outer diameter of the drainage pipe 20 may be, for example, 10 to 16 mm, preferably 12 to 14 mm. At the wave crests, ie the sections of the corrugated drainage pipe 20 with the highest outer diameter, the outer diameter of the drainage pipe 20 may be for example 16 to 24 mm, preferably 18 to 22 mm. The wall thickness of the drainage pipe 20 is not thicker than 1 mm, and preferably not thicker than 0.5 mm. With such a thin wall thickness, rapid heat transfer and high efficiency of the heat exchanger can be effected.

Such a corrugated hose can be inexpensively made of plastic, e.g. Polypropylene or the like. For example, an inexpensive production by extrusion with the aid of a corrugator is possible, which allows easy adjustment of the waveform and the wall thickness. However, it is also possible to make the drainage pipe 20 of a different material, for example metal, e.g. Aluminum or copper. With a metallic material good heat exchanger properties can be achieved. Plastic is not only chemically resistant to the pumped lye, but also inexpensive to manufacture. Further, a plastic corrugated hose can be easily mounted as a drain pipe 20 due to its high flexibility.

In the example shown, the drain pipe 20 is integrally formed. Thus, only a continuous corrugated hose is provided as a drain pipe 20 between the drain pump 19 and the sanitation 21. Thus, no additional sealing or coupling pieces in the drainage pipe 20 must be provided. Furthermore, thus the drainage pipe 20 can be checked for tightness before installation in the fresh water tank 12. Alternatively, it is also possible to mount the drain pipe 20 in the fresh water tank 12 and to be provided with connecting pieces or the like., Which can be connected to lines to the drain pump 19 and the sanitation 21. This allows a modular design of the fresh water tank 12th

By way of example, the side wall 25 of the fresh water container 12 facing away from the housing 5 can be in a substantially planar connection with the rear wall of the washing container 2, or with a thin layer of bitumen or the like, for example 2 mm thick be fixed on this. Such a heat-conducting connection between rinsing tank 2 and fresh water tank 12 causes the heating of the rinse tank 2 by the rinsing water S is also used for heat exchange and the fresh water FW heated in the fresh water tank 12.

LIST OF REFERENCE NUMBERS

1

dishwasher

2

rinse tank

3

door

4

rinsing chamber

5

casing

6

operating device

7

display

8th

control device

9

lower crockery basket

10

upper dish rack

11

Water supply

12

Fresh water tank

13

inlet valve

14

water inlet

15

Clippings

16

circulating pump

17

upper spray arm

18

lower spray arm

19

Drain pump

20

Drain Pipe

21

sanitation facility

22, 23

openings

24

Clipse

25

Side wall

26

ground

FW

fresh water

S

rinse

Claims (10)

1. Dishwasher (1), with a fresh water container (12) for receiving fresh water (FW), and a drainage pipeline (20) for discharging heated waste water (AW) from a dishwasher cavity (2) of the dishwasher (1), wherein the drainage pipeline (20) is guided through the fresh water container (12), and wherein the fresh water (FW) can remove heat from the heated waste water (AW), characterised in that the drainage pipeline (20) is embodied as a corrugated pipeline, and that the dishwasher container (2) is connected to the freshwater container (12) in a heat-conducting manner.
2. Dishwasher (1) according to claim 1, characterised in that the drainage pipeline (20) is embodied as a drainage hose.
3. Dishwasher (1) according to claim 1 or 2, characterised in that the outer diameter of the corrugated pipeline at the wave troughs amounts to 10-16 mm.
4. Dishwasher (1) according to one of claims 1 to 3, characterised in that the outer diameter of the corrugated pipeline at the wave peaks amounts to 18-22mm.
5. Dishwasher (1) according to one of claims 1 to 4, characterised in that the spacing between adjacent wave peaks of the corrugated pipeline amounts to 2-5 mm.
6. Dishwasher (1) according to one of claims 1 to 5, characterised in that the wall thickness of the corrugated pipeline amounts to less than 1 mm.
7. Dishwasher (1) according to one of claims 1 to 6, characterised in that the drainage pipeline (20) is guided through the fresh water container (12) in a meandering manner as a tube coil.
8. Dishwasher (1) according to one of claims 1 to 7, characterised in that the drainage pipeline (20) is embodied for the connection in one piece of a drain pump (19) of the dishwasher (1) to a waste water disposal facility (21).
9. Dishwasher (1) according to one of claims 1 to 8, characterised in that the drainage pipeline (20) is guided on the input side through the bottom (26) of the fresh water container (12).
10. Dishwasher (1) according to one of claims 1 to 9, characterised in that the drainage pipeline (20) is guided on the input side from a lower part of the fresh water container (12) substantially perpendicularly to an upper part of the fresh water container (12).

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