Dishwasher having a liquid transportation line

Abstract

A dishwasher, in particular a commercial single-tank dishwasher or commercial multi-tank dishwasher, for washing washware includes a liquid transportation line (100) with at least one supply line for supplying liquid at a first temperature and comprising at least one discharge line for discharging liquid at a second temperature. The supply line and the discharge line run coaxially in relation to one another, so that either the supply line or the discharge line forms an internal line (10) which runs in the direction of extent of the liquid transportation line (100) within the respectively other supply line or discharge line which for its part forms an external line (20), and thereby form a countercurrent heat exchanger.

Claims

1. A dishwasher for washing washware, wherein the dishwasher has a liquid transportation line comprising at least one supply line for supplying liquid at a first temperature and comprising at least one discharge line for discharging liquid at a second temperature, wherein the supply line and the discharge line run coaxially in relation to one another, so that one of the supply line or the discharge line forms an internal line which runs in a direction of extent of the liquid transportation line within the other of the supply line or discharge line which for its part forms an external line, and thereby form a countercurrent heat exchanger, wherein a continuous intermediate wall is provided between a wall of the internal line and a wall of the external line, wherein the intermediate wall bears against the internal line at least in regions; wherein at least one channel is formed between the intermediate wall and the internal line, wherein the at least one channel runs in the direction of extent of the liquid transportation line, wherein the at least one channel is fluidly connected to ambient atmosphere; wherein the at least one channel is formed by a groove along an inner surface of the intermediate wall.

2. The dishwasher as claimed in claim 1, wherein the internal line has a wall which is formed from a material which has a high specific thermal conductivity, and wherein the external line has a wall which is formed from a material which has a low specific thermal conductivity.

3. The dishwasher as claimed in claim 2, wherein the material of the wall of the internal line is a metal and/or wherein the material of the wall of the external line is a plastic material.

4. The dishwasher as claimed in claim 1, wherein the liquid which can be discharged by means of the discharge line is waste water and is supplied directly to a waste water system.

5. The dishwasher as claimed in claim 1, wherein the liquid which can be supplied by means of the supply line is fresh water and is drawn directly from a drinking water system.

6. The dishwasher as claimed in claim 1, wherein the external line is the supply line, and wherein the first temperature is at least 30 K lower than the second temperature.

7. The dishwasher as claimed in claim 1, wherein the at least one channel is connected to a sensor device in order to detect liquid escaping from the internal line into the channel.

8. The dishwasher as claimed in claim 7, wherein the sensor device is in the form of a pressure sensor.

9. The dishwasher as claimed in claim 7, wherein the sensor device is in the form of an optical sensor which is arranged at at least one line end of the liquid transportation line, in order to detect liquid escaping from the at least one channel.

10. The dishwasher as claimed in claim 1, wherein a T-shaped connection piece which is composed of plastic, having a connection for the external line and having a connection for the internal line is provided at at least one line end of the liquid transportation line.

11. A dishwasher, comprising: at least one tank, and a liquid transportation line comprising at least one supply line and at least one discharge line, wherein the supply line supplies liquid at a first temperature into the dishwasher and the discharge line discharges liquid at a second temperature from the dishwasher, wherein the supply line and the discharge line run coaxially in relation to one another, wherein one of the supply line or the discharge line forms an internal line and the other of the supply line or the discharge line forms an external line, wherein the internal line runs along the liquid transportation line and within the external line to form a countercurrent heat exchanger between the internal line and the external line, wherein a continuous intermediate wall is provided between a wall of the internal line and a wall of the external line; wherein an inner surface of the intermediate wall bears against the internal line at least in a plurality of regions and the inner surface includes a plurality of grooves that form a plurality of flow channels between the intermediate wall and the internal line, wherein each flow channel runs in a direction of extent of the liquid transportation line, wherein each flow channel is fluidly connected to ambient atmosphere.

12. The dishwasher as claimed in claim 11, wherein each channel is connected to a sensor device in order to detect liquid escaping from the internal line into the channel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments will be explained in greater detail below with reference to the drawings, in which:

(2) FIG. 1: shows a perspective view of a liquid transportation line for a dishwasher in line with a first embodiment;

(3) FIG. 2: shows an enlarged region of a line end of the liquid transportation line from FIG. 1;

(4) FIG. 3: shows a sectional side view through the line end of the liquid transportation line shown in FIG. 2 level with a dishwasher according to the first embodiment;

(5) FIG. 4: shows a view of the lumen of the line end from FIGS. 2 and 3;

(6) FIG. 5: shows a perspective view of a liquid transportation line for a dishwasher according to a second embodiment;

(7) FIG. 6: shows an enlarged detail of a line end of the liquid transportation line from FIG. 5;

(8) FIG. 7: shows a further enlarged detail of the line end;

(9) FIG. 8: shows a sectional side view through the line end according to FIG. 6; and

(10) FIG. 9: shows a side view of the lumen of the line end of the liquid transportation line in FIGS. 5 to 8.

DETAILED DESCRIPTION

(11) FIG. 1 shows a perspective view of a liquid transportation line 100 for a dishwasher according to a first embodiment. The liquid transportation line 100 runs in a meandering manner overall and has an internal line 10 which is composed of copper pipe and also has an external line 20 which is composed of a plastic material. As more clearly shown by the enlarged illustration of the line end 101 or 102 in FIG. 2, the liquid transportation line 100 is formed such that the internal line 10 in the form of the copper pipe runs within a corrugated hose which forms the external line 20. The hot waste water is conducted through the metal pipe, that is to say through the internal line 10, while the cold fresh water is routed between said metal pipe (internal line 10) and the corrugated hose (external line 20) in countercurrent. A countercurrent heat exchanger is formed as a result.

(12) As is clear from the sectional side view in FIG. 3, a T-shaped connection piece 50 is provided at one of the two line ends (101, 102), it being possible for the said T-shaped connection piece to be connected in a simple manner to a supply or discharge system by means of a connection 52 for the internal line 10 and by means of a connection 51, which runs approximately at a 90 angle to the connection 52, for the external line 20. To this end, both the connection 51 for the external line and the connection 52 for the internal line have latching lugs, which correspond to a connection plug, or the like for locking purposes.

(13) Therefore, the structure shown in side view in FIG. 4 is the result of looking at the line end from the top. The internal line 10 is therefore limited by a corresponding wall 11, as a result of which a lumen 12 for the liquid transportation is formed in the interior of this wall. The external line 20 accordingly has a wall 21, as a result of which a corresponding lumen 22 of the external line 20 is produced coaxially to the lumen 12 of the internal line 10. The hot waste water is conducted away through the lumen 12 of the internal line 10, while the cooler fresh water, which is generally approximately 40 K cooler, is supplied in countercurrent through the lumen 22 of the external line 20. Particularly effective heat transfer between the media flowing in the lumens 12, 22 is possible in this way.

(14) Analogously to the illustration in FIG. 1, FIG. 5 shows a perspective view of a liquid transportation line 100, but in this case of a dishwasher in line with a second embodiment.

(15) As is clear from the enlarged perspective illustration in FIG. 6, an internal line 10 which is composed of copper pipe and an external line 20 which is composed of a corrugated plastic hose are again provided, but, in line with the second embodiment, an intermediate wall 30 is additionally provided in the region of the wall 11 of the internal line 10. The intermediate wall 30 is formed, for example, by pressing with the internal line 10 and is formed from a material which further allows good heat transfer between the lumen 12 of the internal line 10 and the lumen 22 of the external line 20. As is more clearly shown in the illustrations in FIGS. 7 (perspective enlarged illustration of internal line 10 and intermediate wall 30) and FIG. 9 (plan view of the lumen), the intermediate wall 30 bears against the wall 11 of the internal line 10 by way of a large portion of its surface (more than half of its surface). However, a large number of channels, which are denoted 31 altogether, are formed in the other regions.

(16) In other words: adjacent regions 32 of the intermediate wall 30 are provided on the internal line 10, wherein channels 31 which each run in the direction of extent of the liquid transportation line 100 are provided between these adjacent regions 32. These channels 31 are connected to the surrounding atmosphere in a pressure-related manner at at least one of the line ends 101 and/or 102 of the liquid transportation line 100 in the dishwasher in line with the second embodiment.

(17) A sensor device, for example an optical sensor (103), which serves to identify undesired leakages and the like, is provided at the respective line end 101 or 102. It goes without saying that it is equally possible to provide a plurality of intermediate walls 30. In the event of a leakage, in particular a leakage in the internal line 10 which transports the hot waste water in line with the embodiments 1 and 2, the escaping liquid is, in the case of this leakage, therefore conducted to the line end 101 or 102 where it can be collected without the possibility of contamination due to said escaping liquid affecting the fresh water system or the like. At the same time, a signal can be triggered by means of the sensor (not illustrated) by way of a corresponding control device or the like, said signal closing a solenoid valve (likewise not illustrated) or the like as soon as a leakage is identified. In this case, this solenoid valve is provided between the connection 51 for the external line 20 and the fresh water system.

(18) Owing to the solution provided herein, it is possible to provide an effective and low-cost possible way of ensuring heat recovery in a dishwasher, in particular a commercial single-tank dishwasher or commercial multi-tank dishwasher, wherein the waste water temperature of the waste water which is to be introduced is low enough to be able to meet strict standards, such as the US Uniform Plumbing Code for example, at the same time. At the same time, in particular when an intermediate wall 30 is provided, pressure-related compensation of the channels 31 which are arranged therebetween is provided at the same time, as is likewise required, for example, by the Uniform Plumbing Code.

(19) However, owing to the particular construction, in particular owing to the adjacent regions 32, effective heat transfer between the medium flowing in the internal line and the medium routed in countercurrent in the external line is then possible with the proposed coaxial construction. As a result, hot waste water which is at, for example, 60 C. is cooled to below 50 C. in said countercurrent heat exchanger during a normal dishwashing cycle, as a result of which an otherwise usually elevated consumption of fresh water on account of cold water being admixed with said hot waste water before it is introduced into the waste water system is dispensed with.

(20) It should be noted here that all described features of the embodiments have value in combination or on their own. It is to be clearly understood that the above description is intended by way of illustration and example only, is not intended to be taken by way of limitation, and that other changes and modifications are possible.

LIST OF REFERENCE SYMBOLS

(21) 10 Internal line 11 Wall of the internal line 12 Lumen of the internal line 20 External line 21 Wall of the external line 22 Lumen of the external line 30 Intermediate wall 31 Channel 32 Adjacent region of the intermediate wall 50 T-shaped connection piece 51 Connection for the external line 52 Connection for the internal line 100 Liquid transportation line 101 First line end 102 Second line end