EP-4739185-A1 - METHOD AND APPARATUS FOR MONITORING AND CONTROLLING THE QUALITY OF WATER USED IN A HOUSEHOLD APPLIANCE

EP4739185A1EP 4739185 A1EP4739185 A1EP 4739185A1EP-4739185-A1

Abstract

The present invention relates to an apparatus (1) for monitoring and controlling the quality of water used in a household appliance, comprising a device (4) for monitoring and controlling the water quality and at least one processing and control unit (2, 8), characterized in that said device (4) for monitoring and controlling the water quality in turn comprises at least one fluid-tight casing (13) and at least one reflecting wall (10), where at least one ultrasonic transducer (6) is housed within said fluid-tight casing (13), and wherein said ultrasonic transducer (6) is configured to emit an acoustic wave (A) towards said reflecting wall (10), placed at a known distance (D) from said ultrasonic transducer (6), and to receive the acoustic wave reflected (A') by said reflective wall (10), between said casing (13) and said reflective wall (10) a monitoring volume (V) being defined, adapted to be invaded by said water, so that said emitted acoustic wave (A) and said reflected acoustic wave (A') cross said monitoring volume (V), said at least one processing and control unit (2, 8) being in signal connection with said ultrasonic transducer (6) and being configured to process a signal indicative of a time-of- flight (ToF) of said acoustic wave (A, A') associated with a temperature signal of said water and to generate, on the basis of said time-of-flight (ToF) indicative signal, at least one of: a signal indicative of the degree of hardness of said water, a signal indicative of the degree of turbidity of said water and a signal indicative of the presence of particulate matter and microplastics in said water.

Inventors

ROCCHITELLI, Stefano
DI CICCIO, Daniele
MANSUTTI, ALESSANDRO
MIGLIAVACCA, Alessandro
INAFUKU YOSHIDA, Luis Haruo
BATTIMIELLO, David
ILARE, DENNIS

Assignees

Elettrotecnica Rold Srl

Dates

Publication Date: 20260513
Application Date: 20240705

Claims (13)

1. Apparatus (1) for monitoring and controlling the quality of water used in a household appliance, comprising a device (4) for monitoring and controlling the water quality and at least one processing and control unit (2, 8), characterized in that said device (4) for monitoring and controlling the water quality in turn comprises at least one fluid-tight casing (13) and at least one reflecting wall (10), wherein at least one ultrasonic transducer (6) is housed within said fluid-tight casing (13), and wherein said ultrasonic transducer (6) is configured to emit an acoustic wave (A) towards said reflecting wall (10), placed at a known distance (D) from said ultrasonic transducer (6), and to receive the acoustic wave reflected (A’) by said reflective wall (10), between said casing (13) and said reflective wall (10) a monitoring volume (V) being defined, adapted to be invaded by said water, so that said emitted acoustic wave (A) and said reflected acoustic wave (A’) cross said monitoring volume (V), said at least one processing and control unit (2, 8 ) being in signal connection with said ultrasonic transducer (6) and being configured to process a signal indicative of a time-of-flight (ToF), associated with a temperature signal of said water, of said acoustic wave emitted (A) by said ultrasonic sensor (6) and reflected (A’) by said reflecting wall (10) on said ultrasonic transducer (6), and to generate, on the basis of said time-of-flight (ToF) indicative signal, at least one of: - a signal indicative of the degree of hardness of said water; - a signal indicative of the degree of turbidity of said water; - a signal indicative of the presence of particulate matter and microplastics in said water.
2. Apparatus (1) according to the preceding claim, comprising a temperature sensor (7) housed in said fluid-tight casing (13) and in signal connection with said at least one processing and control unit (2, 8), said at least one processing and control unit (2, 8) being configured to process said signal indicative of a time-of-flight (ToF) of said acoustic wave (A, A’) associated with a temperature signal detected by said temperature sensor (7).
3. Apparatus (1 ), according to claim 1 , wherein said at least one processing and control unit (2, 8) is configured to process said temperature signal on the basis of the variation of the natural frequency of said transducer (6).
4. Apparatus (1), according to one or more of the preceding claims, characterized in that said processing and control unit (2, 8) is configured to generate an initial signal proportional to the duration of the time-of-flight (ToF) of the acoustic wave emitted (A) by the transducer (6) and reflected (A’) by the wall (10) through the monitoring volume (V) in the phase prior to use, and wherein said initial signal is compared with a reference signal of the time interval of the time-of-flight of the acoustic wave emitted by the transducer (6) and reflected by the wall (10) produced in a test phase in distilled water and stored in a memory unit (9), and wherein said control and processing unit (2, 8) carries out the comparison between said initial signal and said reference signal and produces said signal indicative of the degree of the hardness of said water.
5. Apparatus (1), according to one or more of the preceding claims, characterized in that said water is a washing water of a household appliance used for washing and in that said processing and control unit (2,8) is configured to generate a final signal proportional to the duration of the time-of-flight (ToF) of the acoustic wave emitted (A) by the transducer (6) and reflected (A’) by the wall (10) through the monitoring volume (V) at the end of a washing cycle, and a final signal at rest proportional to the duration of the time-of-flight (ToF) after a predetermined period of time following the end of the washing, adapted to allow the deposit, by force of gravity, of the heavier particles present in the washing liquid, and wherein said processing and control unit (2, 8) is configured to compare said final signal and said final signal at rest and to generate said signal indicative of the presence of particulate matter and/or microplastics present in the washing water.
6. Apparatus (1), according to one or more of the preceding claims, characterized in that said water is a washing water from a household appliance used for washing and that said control and processing unit (2, 8) is configured to generate a signal proportional to the duration of the time-of-flight (ToF) of the acoustic wave emitted (A) by the transducer (6) and reflected (A’) by the wall (10) through said washing water of the household appliance in the phase prior to washing, and a final signal at rest proportional to the duration of the time-of-flight (ToF) after a predetermined period of time following the end of the washing process, adapted to allow the deposit, by force of gravity, of the heavier particles present in the washing liquid, and wherein said processing and control unit (2, 8) is configured to compare said initial signal and said final signal at rest and to generate a signal indicative of the turbidity of the liquid during washing.
7. Apparatus (1), according to one or more of the preceding claims, characterized in that said processing and control unit (2, 8) is configured to compare the indicative signals of turbidity and of the presence of particulate matter and/or microplastics in said washing water with quality target signals stored in a memory unit (9), and said processing and control unit (2, 8) is configured, to generate a signal of: - activation of a filtering cycle if the turbidity signal and/or the presence of particulate matter and/or microplastics is greater than the corresponding target signal; - activation of a rinse cycle if the turbidity signal and/or the presence of particulate matter and/or microplastics is greater than the corresponding target signal; - interruption of washing if the turbidity and/or presence of particulate matter and/or microplastics signal is lower than the corresponding target signal.
8. Apparatus (1), according to one or more of the preceding claims, characterized in that said processing and control unit (2, 8) comprises at least one local processing unit (8) integrated into said device (4).
9. Apparatus (1), according to one or more of the preceding claims, characterised in that said processing and control unit (2, 8) comprises at least one central processing and control unit (2) integrated into the processing and control unit of a household appliance.
10. Apparatus (1), according to claims 8 and 9, characterised in that it comprises a communication module configured for the communication of the data processed by said local processing and control unit (8) to said central processing and control unit (2).
11. Apparatus (1), according to one or more of the preceding claims, characterised in that it comprises a battery configured to provide electrical power to said device (4).
12. Household appliance comprising at least one apparatus (1) according to one or more of the preceding claims.
13. Process for monitoring and controlling the quality of washing water of a household appliance, comprising the following steps: a. arranging a household appliance comprising at least one apparatus (1) according to one or more of claims 1 to 11; b. generating an initial signal, through said processing and control unit (2, 8), proportional to the time-of-flight time interval of the wave emitted (A) by the acoustic transducer (6) and reflected (A’) by the wall (10) through the monitoring volume (V) of water; c. comparing, in said processing and control unit (2, 8), said signal with the data recorded during a test phase in distilled water and compensated for the comparison at the same temperature of the liquid; said processing and control unit (2, 8) generates, by comparing said signals, a signal indicative of the water hardness value; d. generating, through said processing and control unit (2, 8), a final signal and a final signal at rest proportional to the time-of-flight time interval of the wave emitted (A) by the acoustic transducer (6) and reflected (A’ ) by the wall (10) through said washing water present in the system at the end of each washing cycle, just after stopping the machine, and after a sufficient time for the heaviest particles to settle in the liquid, respectively; e. comparing, in said processing and control unit (2, 8), said final signals and said final signals at rest and generating, through said processing and control unit (2, 8), a signal indicative of the quantity of particulate matter and/or microplastics present in said washing water; f. comparing, in said processing and control unit (2, 8), the time-of-flight time interval signals of the wave emitted (A) by the acoustic transducer (6) and reflected by the wall (10) through the washing water, which, for example, may contain dissolved salts, organic and inorganic contaminants, bacteria, surfactants, particulate matter and microplastics, present in the system at the end of each washing cycle, after sufficient time for the heaviest particles to settle in the liquid, and in the water in the pre-wash phase; said processing and control unit (2, 8) thus generates a signal indicative of the turbidity of the washing liquid; g. actuating, by means of said processing and control unit (2, 8), water filtering cycles, at the end of the washing cycle, if the signal indicative of turbidity and/or the presence of particulate matter and/or microplastics in the washing water is greater than the corresponding signals stored in said processing and control unit (2, 8); h. by means of said processing and control unit (2, 8), interrupting the washing cycle if the signals indicative of turbidity and of the presence of particulate matter and/or microplastics in the washing water are less than or equal to the corresponding signals stored in said processing and control unit (2, 8); i. activating, through said processing and control unit (2, 8), further rinsing phases at the end of the washing cycle if the indicative signal of turbidity and/or the presence of particulate matter and/or microplastics in the washing water is greater than the corresponding signals stored in said processing and control unit (2, 8).

Description

METHOD AND APPARATUS FOR MONITORING AND CONTROLLING THE QUALITY OF WATER USED IN A HOUSEHOLD APPLIANCE FIELD OF THE INVENTION The present invention relates to a method and apparatus for monitoring and controlling the quality of water in household appliances, and to a household appliance comprising such an apparatus. In particular, the invention relates to an apparatus, as well as a household appliance such as, for example, a washing machine or dishwasher or a coffee machine, adapted to recognise the degree of hardness of the water used by the appliance, but also the degree of turbidity and the presence of particulate matter and/or microplastics in the water, for example in the washing water of washing machines or dishwashers. STATE OF THE ART As is well known, the problem of residues, particulate matter, microplastics and microorganisms remaining on garments and/or objects at the end of the washing process, and the fact that these residues, particulate matter, microplastics and micro-organisms can be discharged at the end of the washing process without being properly filtered, is currently a major concern in the sector of household appliances that wash garments and/or dishes. The presence of these substances at the end of the wash leads not only to their contact with the skin, in the case of fabrics of clothes and garments in general, but even to their ingestion by the user through food and liquids taken in through daily-use dishes, causing various health problems. It is therefore a pressing issue in the industry to be able to manufacture appliances capable of increasingly thorough washing and cleaning of clothes and dishes, thus minimising the presence of these substances. As is well known, the solution commonly adopted by most household appliances on the market today is to wash and clean clothes or dishes according to predefined time programmes. This leads in some cases to the over-washing of clothes and dishes, leading not only to energy wastage by the appliance, but also to excessive water consumption. On the other hand, in other cases, clothes and dishes, even after being treated by specific predefined and recommended programmes of the appliance, still show some presence of substances harmful to the health of users. In order to avoid considerable energy and water wastage, caused by using the appliance according to predefined programmes, and the permanence of harmful substances on clothes or dishes even at the end of the washing cycle, the most advanced appliances assess the degree of cleanliness of objects and textiles by continuously analysing the quality of the washing water in the appliance during the cleaning cycles. In particular, these appliances assess both the degree of turbidity due to the presence of material suspended in the liquid, such as microorganisms, algae or bacteria, colloidal particles and inorganic sediments, and the presence of particulate matter and microplastics. However, the measurement of these two characteristics by the appliances on the market today presents several difficulties and inaccuracies. In fact, the evaluation of the turbidity of the washing water is mainly carried out by means of optical sensors that exploit the absorption and scattering of a light beam by the liquid. However, the measurement loses reliability as the appliance is used, as it is strongly influenced by the degradation of the transparency of the plastic surfaces of the optical device inside the appliance. On the other hand, with regard to the estimation of the presence of particulate matter and microplastics in the washing water, for the time being there is no reliable and low-cost method suitable for use in everyday household appliances. The hardness of the water used in household appliances is also a factor that affects not only the washing efficiency of washing machines and dishwashers, but also, for example, the properties of beverages made with appliances such as coffee machines. SUMMARY OF THE INVENTION In light of the above, it is the task of the present invention to provide an apparatus for monitoring and controlling the quality of water used in household appliances that overcomes the limits of known technology by enabling the estimation of the degree of hardness, turbidity and the presence of particulate matter and/or microplastics in the water itself. It is also an object of the present invention to provide a household appliance comprising said apparatus. Another aim of the invention is to realise an apparatus that simultaneously leads both to better management of washing cycles, thus ensuring efficiency and savings in terms of energy and water in the daily-use system, avoiding over- washing of objects and textiles, and to a higher quality of washing and cleaning at the end of the cycle, leading to the highest degree of removal of substances harmful to the user on the surface of dishes and in clothing. Furthermore, it is an object of the present invention to provide an apparatus for monit