DE102011084178B3 - Detecting device for use in microcontroller to detect deposits in inner space of dishwasher, has determining unit determining adiposity of measuring electrode based on determined conductivities - Google Patents

Abstract

The device (1) has a first determining unit for determining electrical conductivity between a reference electrode (12) and a counter electrode (13). A second determining unit determines electric conductivity between a measuring electrode (11) and the counter electrode. A third determining unit determines adiposity of the measuring electrode based on the conductivity between the reference electrode and the counter electrode and the conductivity between the measuring electrode and the counter electrode. Independent claims are also included for the following: (1) a control device for controlling a household appliance (2) a method for detecting deposits in an inner space of a household appliance.

Description

The present invention relates to a device for detecting deposits in an interior of a household appliance and a household appliance with such a device. Furthermore, the invention relates to a method for detecting deposits in an interior of a household appliance.

Many components in the interior of a dishwasher are conventionally made of a polymer, i. H. made of plastic. The polymers used in the interior of the household appliance are generally lipophilic, so that deposits, in particular from fats, can form on these. The reason why fats can accumulate, especially on polymeric surfaces, is that a large number of polymers have a lipophilic surface, i. H. a surface energy matching the fat.

This negative effect of the deposition of fats on components of the interior of the dishwasher intensifies the deeper the temperature of the rinsing liquor is in the interior. Because of the tendency to save energy and thus to ever lower temperatures of the rinsing liquor, the effect of the fatty deposits also increases accordingly. For example, it is possible at rinsing temperatures below 50 ° C that fats and possibly other dirt components are not completely melted or dissolved and thereby accumulate as deposits on the components of the interior. As a result, deposits can accumulate and accumulate over time, especially on polymeric components of the interior.

A conventional apparatus for characterizing impurities in liquids in a household appliance is in DE 102 57 238 A1 described.

Against this background, an object of the present invention is to provide a way of detecting deposits in the interior of a household appliance.

According to the invention, a device for detecting deposits in an interior of a household appliance, in particular a water-conducting household appliance, proposed. The device or detection device has a lipophilic measurement electrode for receiving deposits, a lipophobic reference electrode, a lipophobic counterelectrode, a first determination means, a second determination means and a determination means.

The first determining means is arranged to determine the electrical conductivity between the reference electrode and the counter electrode. The second determining means is arranged to determine the electrical conductivity between the measuring electrode and the counter electrode. The determining means is arranged to determine an adiposity of the measuring electrode as a function of the determined conductivity between the reference electrode and the counter electrode and the determined electrical conductivity between the measuring electrode and the counter electrode.

Depending on the obesity or the deposits on the measuring electrode, the degree of deposits in the interior of the household appliance can be determined. Between the obesity of the measuring electrode and the degree of deposits in the interior of the household appliance, ie on the lipophilic components of the interior of the household appliance, there is a predetermined proportionality, since the material properties of the lipophilic components of the interior and the measuring electrode are already known. On the basis of the specific deposits in the interior of the household appliance, a control device connected to the detection device of the household appliance can take appropriate countermeasures. For example, the control device may perform a cleaning program for cleaning the interior of the household appliance. The cleaning program includes, for example, a high-temperature program or the addition of a special surfactant. Suitable measures that the control device can take when exceeding the deposits in the interior of the household appliance over a predetermined threshold, are in the DE 10 2008 040 651 B3 , of the DE 10 2008 040 650 A1 and in the DE 10 2008 040 647 A1 described.

The deposits consist essentially of fats, which accumulate over time on the polymeric components of the interior. The deposits, in addition to the fats and other dirt components, such as lime, have.

By providing the device or detection device in the interior of the household appliance, the temperature of the rinsing liquor can be further reduced since deposits are detectable and thus removable again. This can save energy.

In one embodiment, the determining means is configured to determine the degree of fatty acidity of the measuring electrode as a function of a ratio, in particular a quotient, between the determined conductivity between the reference electrode and the counterelectrode and the determined electrical conductivity between the measuring electrode and the counterelectrode.

In a further embodiment, the measuring electrode, the reference electrode and the counterelectrode have the same areas.

In a further embodiment, the reference electrode and the counter electrode are made of a conductive, inert material, for example steel, in particular stainless steel.

In one embodiment, the measuring electrode is formed from a lipophilic, electrically conductive material. In particular, the measuring electrode is made of a lipophilic, electrically conductive polymer.

In a further embodiment, the lipophilic, electrically conductive polymer of the measuring electrode has metal fibers, in particular stainless steel fibers, carbon black and / or carbon nanotubes as filling material.

In one embodiment, the determining means is adapted to determine the degree of deposits in the interior of the household appliance as a function of the particular obesity of the measuring electrode.

In a further embodiment, the first determination means is adapted to measure the electrical conductivity between the reference electrode and the counter electrode as a function of a distance between the reference electrode and the counter electrode, a surface of the reference electrode and an electrical resistance falling between the reference electrode and the counter electrode.

In particular, the electrical conductivity is determined by means of alternating current so that neither the electrodes are polarized nor can electrochemical double layers, such as, for example, a Hemmholz double layer or a Gouy-Chapman double layer, form.

In a further embodiment, the first determination means for determining the electrical conductivity between the reference electrode and the counter electrode is arranged. The second determining means is arranged to determine the electrical resistance between the measuring electrode and the reference electrode. The calculating means is set up for calculating a current area of the measuring electrode as a function of the determined electrical conductivity and the determined resistance. The determining means is arranged to determine a degree of the deposits on the measuring electrode depending on the ratio between the calculated current area and the predetermined area of the measuring electrode.

In a further embodiment, the first determination means determines the electrical conductivity σ by means of the following equation (1):

Here, I _ref denote the distance between the reference electrode and the counter electrode, R _ref the resistance between the reference electrode and the counter electrode and A _ref the surface of the reference electrode.

σ = 1 / ρ (3) Equation (1) above results from Equations (2) and (3) below.

σ = 1 / ρ (3)

In a further embodiment, the calculation means is adapted to calculate the current area A _{mess of} the measuring electrode as a function of a distance I _mess between the measuring electrode and the reference electrode, the determined resistance R _mess between the measuring electrode and the reference electrode and the determined electrical conductivity σ.

In a further embodiment, the calculating means calculates the actual area A _{mess of} the measuring electrode by means of the following equation (4):

In this case, I _mess denotes the distance between the measuring electrode and the counter electrode, R _mess the resistance between the measuring electrode and the counter electrode and σ the determined electrical conductivity.

If deposits, for example from fats, are deposited on the measuring electrode, the area of the measuring electrode changes. Due to the area dependence of the specific resistance ρ, a change in the area of the measuring electrode also causes a change in the electrical resistance R _mess falling between the measuring electrode and the counter electrode, and thus the conductivity. By the first determination means, in particular via a reference measurement, the electrical conductivity σ of the wash liquor is determined, whereby a reference point is known. Thus, the current area A _mess from the above equation (4) can be determined.

The respective means, first determination means, second determination means, calculation means and determination means, can be implemented in terms of hardware or software technology. In a hardware implementation, the respective means may be designed as a device or as part of a device, for example as a computer or as a microprocessor. In a software implementation, the respective means may be designed as a computer program product, as a function, as a routine, as part of a program code or as an executable object.

Furthermore, a control device for controlling a domestic appliance, in particular a water-conducting household appliance, is proposed which has a device for detecting deposits in the interior of the domestic appliance as described above.

In one embodiment, the control device is designed as a microcontroller. In particular, the microcontroller integrates the first determination means, the second determination means and the determination means.

In one embodiment, the control device is set up to carry out a cleaning program for cleaning the interior of the household appliance as a function of the particular obturation of the measuring electrode.

Further, a household appliance, in particular a water-conducting household appliance, proposed, which has a device as described above for the detection of deposits in the interior of the household appliance. The household appliance is in particular a dishwasher.

Furthermore, a method for the detection of deposits in an interior of a household appliance, in particular a water-conducting household appliance, proposed. For this purpose, a lipophilic measuring electrode for receiving deposits, a lipophobic reference electrode and a lipophobic counter electrode are used. In a first step, the electrical conductivity between the reference electrode and the counter electrode is determined. In a second step, the electrical conductivity between the measuring electrode and the reference electrode is determined. In a third step, the obesity of the measuring electrode is determined as a function of the determined conductivity between the reference electrode and the counter electrode and the determined electrical conductivity between the measuring electrode and the counter electrode.

Furthermore, a computer program product is proposed, which causes a program-controlled device to carry out a method as described above for the detection of deposits in an interior of a domestic appliance.

A computer program product such as a computer program means can be provided or supplied, for example, as a storage medium, such as a memory card, USB stick, CD-ROM, DVD or in the form of a downloadable file from a server in a network. This can be done, for example, in a wireless communication network by the transmission of a corresponding file with the computer program product or the computer program means.

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.

It shows:

1 a schematic view of an embodiment of a measuring unit of a detection device with clean measuring electrode;

2 a schematic view of the embodiment of the measuring unit of 1 with dirty measuring electrode;

3 a schematic view of a first embodiment of an evaluation of the detection device;

4 a schematic view of a second embodiment of the evaluation of the detection device;

5 a schematic view of an embodiment of a control device of a household appliance;

6 a schematic view of an embodiment of a household appliance; and

7 a schematic flow diagram of an embodiment of a method for detecting deposits in an interior of a household appliance.

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

In the 1 and 2 is a schematic view of an embodiment of a measuring unit 10 a detection device 1 shown. Next to the measuring unit 10 includes the detection device 1 also an evaluation unit 20 (please refer 3 and 4 ).

The detection device 1 with the measuring unit 10 and the evaluation unit 20 is for the detection of deposits A in an interior 2 of a household appliance 3 set up (see 6 ). The household appliance 3 is for example a water-conducting household appliance, in particular a dishwasher. The measuring unit 10 of the 1 has a lipophilic measuring electrode 11 , a lipophobic reference electrode 12 and a lipophobic counter electrode 13 , Consequently, only the measuring electrode 11 suitable for receiving deposits A. In contrast, neither on the lipophobic reference electrode 12 still on the lipophobic counter electrode 13 Deposit deposits A The 1 and 2 differ in that in the 1 no deposits A on the measuring electrode 11 present and on the measuring electrode 11 of the 2 Deposits A are deposited.

The measuring electrode 11 has a predetermined area A in _front . In this case, the predetermined area A relates in _{front of} the measuring electrode 11 on the surface of the measuring electrode 11 without deposits A, especially before use in the household appliance 3 , Accordingly, the reference electrode 12 a predetermined area A _ref and the counter electrode 13 a predetermined area A _against . In particular, the predetermined areas A are _before , A _ref and A _against the measuring electrode 11 , the reference electrode 12 and the counter electrode 13 identical.

The reference electrode 12 and the counter electrode 13 are made of steel, in particular of stainless steel, for example. In contrast, the measuring electrode 11 formed from a lipophilic, electrically conductive material. The lipophilic, electrically conductive material is, for example, a lipophilic, electrically conductive polymer. For example, the lipophilic, electrically conductive polymer of the measuring electrode 11 Metal fibers, in particular stainless steel fibers, carbon black and / or carbon nanotubes (CNT).

On the measuring electrode 11 of the 2 are deposits A, for example, from fats of the rinse liquor, attached. This changes the area of the measuring electrode 11 over the time from the predetermined area A _before to a respective current area A _mess (see 2 ). Furthermore, the distance between the reference electrode 12 and the counter electrode 13 denoted by I _ref . Accordingly, the distance between the measuring electrode 11 and the counter electrode 13 denoted by I _mess . The distances I _ref and I _mess are in particular identical.

As already stated above, the detection device has 1 next to the measuring unit 10 an evaluation unit 20 , This shows the 3 shows a schematic view of a first embodiment of an evaluation unit 20 the detection device 1 ,

The evaluation unit 20 of the 3 has a first investigation 21 , a second investigation 22 and a determining agent 24 , The first investigation 21 determines the electrical conductivity σ1 between the reference electrode 12 and the counter electrode 13 , Furthermore, the first investigation means 21 the determined electrical conductivity σ1 the determination means 24 ready.

The second investigation 22 determines the electrical conductivity σ2 between the measuring electrode 11 and the counter electrode 13 , Furthermore, the second investigation means 22 the determined electrical conductivity σ 2 the determining means 24 ready.

The determining agent 24 determines an obesity V of the measuring electrode 11 as a function of the determined conductivity σ1 between the reference electrode 12 and the counter electrode 13 and the determined electrical conductivity σ2 between the measuring electrode 11 and the counter electrode 13 ,

Furthermore, the shows 4 a schematic view of a second embodiment of an evaluation 20 the detection device 1 ,

The evaluation unit 20 of the 4 has a first investigation 21 , a second investigation 22 , a calculation tool 23 and a determining agent 24 , The first investigation 21 determines the electrical conductivity σ1 between the reference electrode 12 and the counter electrode 13 , Furthermore, the first investigation means 21 the determined electrical conductivity σ1 the calculation means 23 ready.

The second investigation 22 determines the electrical resistance R _mess between the measuring electrode 11 and the counter electrode 13 , The second investigation 22 represents the detected electrical resistance R _mess the computing means 23 ready.

The calculation means 23 calculates the current area A _{mess of} the measuring electrode as a function of the determined electrical conductivity σ1 and the determined electrical resistance R _mess . The calculation means 23 represents the calculated current area A _{mess of} the measuring electrode 11 the determining agent 24 ready. The determining agent 24 determines the degree G of fatty deposits or deposits A on the measuring electrode 11 (please refer 2 ) as a function of the ratio between the calculated actual area A _mess and the predetermined area A in _{front of} the measuring electrode 11 ,

bestimmbar.Thus, the degree G of the deposits A on the measuring electrode 11 through the function

determinable.

Next is the determining agent 24 in particular adapted to the degree of deposits A in the interior 2 of the household appliance 3 depending on the degree G of the deposits on the measuring electrode 11 to determine.

In 5 is a schematic view of an embodiment of a control device 4 for controlling a household appliance 3 shown. The control device 4 For example, it is designed as a microcontroller and has a detection device 1 on. The detection device 1 has a measurement unit 10 and an evaluation unit 20 , The measuring unit 10 is for example according to the embodiment of 1 and 2 educated. The evaluation unit 20 For example, corresponds to the first embodiment of the 3 or the second embodiment of 4 ,

6 shows a schematic view of an embodiment of a household appliance 3 , The household appliance 3 is for example a water-conducting household appliance, in particular a dishwasher.

In the interior 2 of the household appliance 3 is a control device 4 with a detection device 1 arranged. The control device 4 is according to the embodiment of 5 educated.

In 7 is a schematic flow diagram of an embodiment of a method for detecting deposits in an interior of a household appliance shown. For this purpose, a lipophilic measuring electrode for receiving deposits, a lipophobic reference electrode and a lipophobic counter electrode are used.

In step S1, the electrical conductivity σ1 between the reference electrode and the counter electrode is determined.

In step S2, the electrical conductivity σ2 between the measuring electrode and the reference electrode is determined.

Steps S1 and S2 may be performed sequentially, in reverse order, or simultaneously.

In step S3, a fattening of the measuring electrode as a function of the determined conductivity σ1 between the reference electrode and the counter electrode and the determined electrical conductivity σ2 between the measuring electrode and the counter electrode 13 certainly.

The degree of deposits in the interior of the household appliance is then determined as a function of the particular fatty deposits or of the specific degree of deposits on the measuring electrode.

Although the present invention has been described with reference to embodiments, it is variously modifiable.

LIST OF REFERENCE NUMBERS

1

contraption

2

inner space

3

household appliance

4

control device

10

measuring unit

11

measuring electrode

12

reference electrode

13

counter electrode

20

evaluation

21

first investigation

22

second investigation

23

calculation means

24

determining means

A _mess

current area of the measuring electrode

A _before

predetermined area of the measuring electrode

A _ref

predetermined area of the reference electrode

A _against

predetermined area of the counter electrode

G

Degree of obesity

I _mess

Distance between measuring electrode and counter electrode

I _ref

Distance between reference electrode and counter electrode

R _mess

Resistance between measuring electrode and counter electrode

R _ref

Resistance between reference electrode and counter electrode

σ1

electrical conductivity between the reference electrode and the counter electrode

σ2

electrical conductivity between the measuring electrode and the counter electrode

V

adiposity

Claims (13)

Contraption ( 1 ) for the detection of deposits (A) in an interior space ( 2 ) of a household appliance ( 3 ) with a lipophilic measuring electrode ( 11 ) for receiving deposits (A), a lipophobic reference electrode ( 12 ), a lipophobic counterelectrode ( 13 ), a first investigative 21 ) for determining the electrical conductivity (σ1) between the reference electrode ( 12 ) and the counter electrode ( 13 ), a second investigative 22 ) for determining the electrical conductivity (σ 2) between the measuring electrode ( 11 ) and the counter electrode ( 13 ), and a determination means ( 24 ) for determining an obesity (V) of the measuring electrode ( 11 ) as a function of the determined conductivity (σ1) between the reference electrode ( 12 ) and the counter electrode ( 13 ) and the determined electrical conductivity (σ2) between the measuring electrode ( 11 ) and the counter electrode ( 13 ). Device according to claim 1, characterized in that the determining means ( 24 ) is adapted to determine the degree (G) of obesity (V) of the measuring electrode ( 11 ) as a function of a ratio between the determined conductivity (σ1) between the reference electrode ( 12 ) and the counter electrode ( 13 ) and the determined electrical conductivity (σ2) between the measuring electrode ( 11 ) and the counter electrode ( 13 ). Device according to claim 1 or 2, characterized in that the measuring electrode ( 11 ), the reference electrode ( 12 ) and the counterelectrode ( 13 ) have equal areas (A _before , A _ref , A _against ). Device according to one of claims 1 to 3, characterized in that the reference electrode ( 12 ) and the counterelectrode ( 13 ) are made of steel. Device according to claim 4, characterized in that the reference electrode ( 12 ) and the counterelectrode ( 13 ) are made of stainless steel. Device according to one of claims 1 to 5, characterized in that the measuring electrode ( 11 ) is formed from a lipophilic, electrically conductive polymer. Apparatus according to claim 6, characterized in that the lipophilic, electrically conductive polymer of the measuring electrode ( 11 ) Has metal fibers. Apparatus according to claim 7, characterized in that the lipophilic, electrically conductive polymer of the measuring electrode ( 11 ) Has stainless steel fibers, carbon black and / or carbon nanotubes. Device according to one of claims 1 to 8, characterized in that the determining means ( 24 ) is adapted to the degree of deposits (A) in the interior ( 2 ) of the household appliance ( 3 ) as a function of the particular obesity (V) of the measuring electrode ( 11 ). Control device ( 4 ) for controlling a household appliance ( 3 ), which is a device ( 1 ) for the detection of deposits (A) in an interior space ( 2 ) of the household appliance ( 3 ) according to one of claims 1 to 9. Control device according to Claim 10, characterized in that the control device ( 4 ) is designed as a microcontroller, which contains the first determination means ( 21 ), the second investigative tool ( 22 ) and the determining means ( 24 ) integrated. Household appliance with a device ( 1 ) for the detection of deposits (A) in an interior space ( 2 ) of the household appliance ( 3 ) according to one of claims 1 to 9. Method for detecting deposits in an interior of a domestic appliance with a lipophilic measuring electrode for receiving deposits, a lipophobic reference electrode and a lipophobic counterelectrode, with the following steps: Determining (S1) the electrical conductivity (σ1) between the reference electrode and the counterelectrode, Determining (S2) the electrical conductivity (σ 2) between the measuring electrode and the reference electrode, and Determining (S3) an adiposity of the measuring electrode as a function of the determined conductivity (σ1) between the reference electrode and the counterelectrode and the determined electrical conductivity (σ2) between the measuring electrode and the counterelectrode.

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