EP0741990A2 - Dispositif pour signaler la concentration en sel utilisé pour la régénération des résines dans une machine à laver - Google Patents

Dispositif pour signaler la concentration en sel utilisé pour la régénération des résines dans une machine à laver Download PDF

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Publication number
EP0741990A2
EP0741990A2 EP96107207A EP96107207A EP0741990A2 EP 0741990 A2 EP0741990 A2 EP 0741990A2 EP 96107207 A EP96107207 A EP 96107207A EP 96107207 A EP96107207 A EP 96107207A EP 0741990 A2 EP0741990 A2 EP 0741990A2
Authority
EP
European Patent Office
Prior art keywords
salt
water
regeneration
function
hardness
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP96107207A
Other languages
German (de)
English (en)
Other versions
EP0741990A3 (fr
Inventor
Valerio Aisa
Luigi Alluto
Gaetano Olivieri
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Whirlpool EMEA SpA
Original Assignee
Merloni Elettrodomestici SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Merloni Elettrodomestici SpA filed Critical Merloni Elettrodomestici SpA
Publication of EP0741990A2 publication Critical patent/EP0741990A2/fr
Publication of EP0741990A3 publication Critical patent/EP0741990A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
    • A47L15/00—Washing or rinsing machines for crockery or tableware
    • A47L15/42—Details
    • A47L15/4229—Water softening arrangements

Definitions

  • the present invention relates to a signal system of the salt concentration used for resin regeneration in a washing machine, specifically a household dishwasher as per the preamble of Claim 1, and a method to control the salt level in a softening system for the water used in a washing machine as per the preamble of Claim 10.
  • washing machines specifically household dishwashers
  • a damping system of water hardness In such systems the washing water from the mains is flown through a resin compartment to reduce its calcium contents that would inhibit the action of the washing agents and cause calcareous deposits.
  • the softening systems comprise a kitchen salt tank that needs periodic filling due to the salt consumption caused by the resin regeneration processes.
  • Decalcifier or softener devices of the above type and their relevant regeneration method are known as such, so a detailed description is not required in this context.
  • the quantity of salt consumed to reactivate the resins will also be higher. In other words, this means that salt consumption is directly proportional to the degree of water hardness used in the washing machine.
  • the washing machines of the above type usually incorporate a device suitable to inform the user about exhaustion of the salt used for the resins regeneration.
  • a signalling device usually comprises a warning light on the machine control board, whose lighting is caused by a proper float associated with the salt tank. Therefore, when said warning light illuminates the dishwasher user is warned that new salt should be added to avoid total exhaustion of the resins effectiveness to lower the hardness of the water to the machine, due to the non execution of a number of regeneration cycles .
  • the above warning light is usually enabled by the closing of a contact, normally "reed” type, caused by a magnet located on said float, which take a position depending on the brine density available in the salt tank. Therefore it is obvious that when salt concentration decreases, also the density of the water-salt mixture will decrease causing the float to change its height position till said magnet approaches the reed contact of the warning light signalling a lack of salt and lights it up.
  • DD indicates a water softener device as a whole, comprising a resin compartment R and a salt compartment S.
  • G shows schematically a float device, whose position changes according to the quantity of salt available in the compartment S.
  • the float device G can substantially be of the type mentioned at the beginning of this description, i.e. with a reed type contact actuated by a magnet on a proper float moving inside a chamber associated with the compartment S.
  • the float G in the system object of this invention is used differently from the known state of the art, as better explained further on.
  • Reference number 2 indicates a pipe connecting the washing machine with the household water supply network; number 3 indicates a solenoid valve that manages the water supply to the machine.
  • the pipe 2 is connected with a multipurpose device, not shown in the figure being known as such, comprising a socalled "air-breaker" (consult eg. Italian patent no. 1.238.419 in the name of the Applicant). From this complex device water flows through a pipe AL to the resins compartment R, to be softened. Viceversa, V shows a pipe to deliver the softened water, i.e. from the device DD to the washing tub of the machine, not shown in the figure.
  • the pipe AR indicates a pipe to deliver a determined volume of water collected in the above multipurpose device to the compartment S to obtain the brine required for the various resins regeneration cycles.
  • the pipe AR carries a solenoid valve E.V. whose opening lets a determined volume of water flow from said multipurpose device to the tank S, so that a corresponding amount of brine can flow from the compartment S to the resins compartment R, to reactivate resins effectiveness.
  • the device DD is based on a known concept and operation, so it will not be further described in detail.
  • MP indicates an electronic microcontroller making part of the machine control system.
  • a microcontroller MP can for instance be a part of an either electronic or hybrid timer of the machine, i.e. of the device controlling the wash cycles to be executed by the machine on user's actuation.
  • the microcontroller MP has an adequate internal clock, indicated by CLOCK, permanent memory means indicated by ROM and nonvolatile read/write memory means, not shown.
  • illumination of the warning light L to signal a lack of salt is not controlled by the float device G as it is usual in the known state of the art, but it is controlled by the microcontroller MP.
  • the present invention is based in fact on the acknowledgement that the float signal system, as typical for the known state of the art, is reliable enough only to switch off the warning light after a salt filling of the compartment by the user, as in this case the thrust generated on the float is such to win likely frictions and is related, anyway, to a considerable salt concentration change not subject to a likely brine non-homogeneity status.
  • the thrust generated on the float is such to win likely frictions and is related, anyway, to a considerable salt concentration change not subject to a likely brine non-homogeneity status.
  • such a float system is often very inaccurate to indicate a lack of salt.
  • the washing machine object of the present invention has a control unit provided with a microcontroller, conveniently programmed according to the rules of the fuzzy logic.
  • the permanent memory ROM associated with such a microcontroller has an adequate codified knowledge base, obtained through the experience of technical people and experimental investigations.
  • the microcontroller MP acknowledges the procedures of salt consumption as a function of the wash cycles and resin regeneration cycles, of the water hardness and of the characteristics of the machine hydraulic system.
  • the machine object of this invention is provided with a device to measure the resistivity of the water from the mains, which according to this invention is used to measure the degree of water hardness.
  • Such a device comprises two electrodes, shown in Fig. 1 by the letters A and B, consisting of electrically conductive elements inserted on the pipe 2 for water inlet from the mains supply.
  • both electrodes A and B are electrically isolated to each other.
  • Such a current flow feeds a charge transient of capacitor C and will stop when said transient endson its conclusion, i.e. when a voltage equal to the value of E is available at the terminals of capacitor C.
  • the transient is generated by the microcontroller MP and its duration depends both on the capacity of capacitor C and resistivity value of the medium through which the charge current is flowing, i.e. the water from the mains.
  • information about the resistivity of the washing water can be obtained by measuring the duration of the charge time of said capacitor C.
  • Such a measurement is executed by the microcontroller MP, whose internal clock (CLOCK) is able to measure time with a good resolution (eg. 1 microsec resolution).
  • a digital input of microcontroller MP is connected with the terminals of capacitor C, whereas one digital output, indicated by OUT, is used to pilot a transistor Q, which is used as a switch to control the transient and whose manifold is connected with the terminals of capacitor C.
  • Charging time of capacitor C is measured by the following operations of microcontroller MP:
  • the microcontroller MP conveniently programmed according to the fuzzy logic techniques and provided with an adequate knowlwdge base, is able to calculate water resistivity from the measurement of the charge time of said capacitor.
  • the microcontroller is capable of calculating the degree of water hardness from the mains, which is easy to desume through the water resistivity value according to said knowledge base in fuzzy logic.
  • the electronic control system of the machine according to the present invention is able to know the degree of water hardness through the sensors A and B. Moreover, it appears also quite easy to insert in the ROM memory of the microcontroller MP any information derived from the experience related to typical salt consumption procedures as a function of wash cycles and regeneration cycles, of water hardness and of the characteristics of the machine hydraulic system (i.e. water volumes used during the various steps).
  • illumination of the warning light L occurs after a certain number of wash cycles (and consequently of resin regenerations) or, more in general, after the flowing through the resins of a determined volume of water of a given hardness degree. It should also be pointed out that according to this invention the cycle or volume count is strictly related to their number and degree of water hardeness.
  • the nonvolatile ROM memory contains proper tables or algorythms, letting the microcontroller MP to evaluate salt consumption during each wash cycle as a function of the volume of softened water during said cycle and as a function of the value of water hardness detected by the sensor, which is obviously included in a preset range of values.
  • the microcontroller MP will update its own counter of the regeneration cycles or volumes of softened water through its nonvolatile read/write memory means.
  • the microcontroller MP may reset its internal counter for the regeneration cycles (or volumes of softened water) and start a new counting cycle.
  • the signal associated with the reed contact of the floating device G - practically reliable only when salt is introduced in the relevant compartment - can be conveniently used according to the present invention.
  • the operation of the washing machine according to the present invention is as follows.
  • the float system G is calibrated to detect the introduction of a determined quantity of salt by the user. Therefore, to switch off the warning light L, if lighted, the user has to introduce in the compartment S a quantity of salt at least capable of opening the reed contact, thus resetting the control device of the warning light L.
  • the opening of the reed contact associated with the float will also inform the microcotroller MP that the user has at least introduced a certain quantity of salt. Then the microcontroller will reset said internal counter of the regeneration cycles.
  • the microcontroller MP starts a new cycle counting after the salt introduction in the compartment S.
  • the microcontroller MP based on the data codified in its memory will evaluate the capability of salt consumption of each cycle during the relevant regeneration process.
  • the microcontroller operates a "ponderated average" of resins regeneration till a preset limit value based on the experience and codified in the microcontroller storage is reached, according to which in the compartment S no more salt is available.
  • the salt lack is not physically detected but is deduced by the microcontroller MP according to the data obtained through investigations based on measurements and experience.
  • the microprocessor MP is then able to calculate a "virtual" salt level inside the relevant compartment S washing by washing; when such a virtual level goes down to a preset minimum value, the microcontroller itself will control illumination of the warning light L.
  • the signal system of the machine according to the present invention invention requires the user to introduce at least a certain quantity of salt in the compartment S, below which the signal that salt is lacking could be wrong.
  • the control device MP will keep the warning light L continuously illuminated having received no signal of salt level filling by the user.
  • the resin regeneration cycles will be normally executed by the machine provided the user fills the salt compartment.
  • the persisting illumination of the warning light L will at any rate advise the user to call for technical assistance.
  • the warning light L illuminated all time will warn the technical man of a local trouble, i.e. the reed contact of the float system G not operating properly or likely interruption, or stil a wiring shortcircuit of the two wires transferring the signal from the reed contact to the control logic MP.
  • the total number of regeneration cycles to be reached before salt exhaustion is signaled is automatically selected by the machine control system, considering how the inlet procedures of the water to be softened - managed by a suitable level sensor (such as a pressure switch or turbine metering device) have been made during the various wash cycles.
  • a suitable level sensor such as a pressure switch or turbine metering device
  • the nonvolatile storage ROM of the microcontroller MP contains suitable tables or algorythm enabling the microcontroller MP to know for each type of wash cycle being selected the relevant volume of softened water and relevant consumption of regeneration salt as a function of the value of water hardness.
  • This invention is also particularly convenient for application in washing machines whose resin regeneration cycles may have different procedures, i.e. with variable volumes of regeneration water, managed by a solenoid valve as a function of water hardness.
  • the count of regeneration cycles can be optionally replaced by the count of the volume of water used for the regeneration, should such a quantity change according to water hardness and/or to the selected wash cycle.
  • the nonvolatile memory MP contains suitable tables or algorythms indicating to the microcontroller M P the opening time for the solenoid valve E.V. of Fig. 1 with reference to each value supplied by the water hardness sensor and included in a preset range of values, provided to control water inlet for regeneration purposes. Obviously, an exact volume of the the water used will correspond to a given opening time of the solenoid valve E.V.
  • the control unit is able to relate the values of water hardness, of the volume of regeneration water and of the volume of softened water to obtain the signal that salt is lacking.
  • Such an application of the invention is shown as a diagram in Fig. 2, indicating on the abscissa axis the volumes of softened water (liters), on the ordinate axis the possible values of water hardness (French degrees, dHF) and on the horizontal arrows the volumes of water (centiliters) used for resins regeneration and the relevant activation times of solenoid valve E.V. for regeneration water control.
  • these examplifying data are related to the max capacity of the salt compartment or, in the case described above, to the quantity of salt required to cause the warning light L to switch out.
  • each regeneration will take place with 190 cc of water, namely 40 secs opening of the solenoid valve E.V.
  • illumination of the warning light is enabled by the microcontroller after about 740 liters of water have been softened.
  • the signal system object of this invention offers an increased accuracy in respect to the known state of the art.
  • this invention there is practically no longer a need for a physical detecting system of the salt consumption but an accurate evaluation of it is required to obviate to the problems of the known state of the art, which can derive from a lack of homogeneity of the fluid density in the salt tank, from a likely mechanical jamming of the float and from calibration difficulties related to the float weight.
  • sensing means for salt concentration or hardness of the water exiting the DD device so as to transfer more information to the microcontroller MP.
  • sensing means can in fact be obtained with other means similar to the ones indicated by A and B.
  • codification of proper data and fuzzy rules in the ROM memory associated with the microcontroller will let the latter to derive the degree of salt concentration or its hardness from the water resistivity.
  • the microcontroller MP can then relate with the information previously mentioned (water hardness and/or volume of softened water and/or volume of water used for regeneration) also the value of salt concentration or hardness of the water exiting from the device DD.
  • the microcontroller MP is able to determine very precisely and economically (low cost incidence of complementary electrodes A and B) through a proper knowledge base codified in the ROM memory means when salt is lacking in the compartment S.
  • the float system G practically has the sole function of informing the control logic MP about salt filling in the tank S.

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  • Control Of Washing Machine And Dryer (AREA)
  • Detail Structures Of Washing Machines And Dryers (AREA)
EP96107207A 1995-05-09 1996-05-07 Dispositif pour signaler la concentration en sel utilisé pour la régénération des résines dans une machine à laver Withdrawn EP0741990A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITTO950361 1995-05-09
IT95TO000361A IT1279192B1 (it) 1995-05-09 1995-05-09 Sistema per la segnalazione della concentrazione del sale che viene utilizzato per la rigenerazione di resine in una macchina di lavaggio.

Publications (2)

Publication Number Publication Date
EP0741990A2 true EP0741990A2 (fr) 1996-11-13
EP0741990A3 EP0741990A3 (fr) 1997-01-08

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EP96107207A Withdrawn EP0741990A3 (fr) 1995-05-09 1996-05-07 Dispositif pour signaler la concentration en sel utilisé pour la régénération des résines dans une machine à laver

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EP (1) EP0741990A3 (fr)
IT (1) IT1279192B1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10027844A1 (de) * 1999-12-18 2001-06-28 Aweco Appliance Sys Gmbh & Co Haushaltsmaschine
WO2001018298A3 (fr) * 1999-09-03 2001-08-09 T & P Spa Systeme de reduction de la durete de l'eau et procedes de controle
EP1723889A1 (fr) * 2005-05-13 2006-11-22 INVENSYS CONTROLS ITALY Srl Méthode et dispositif pour indiquer le besoin de remplissage de substance de régénération pour l'adoucisseur dans une machine à laver des ustensiles tel que lave-vaisselle
US20100229893A1 (en) * 2007-10-31 2010-09-16 Bsh Bosch Und Siemens Hausgerate Gmbh Method for operating a water-bearing domestic appliance
EP2044876A3 (fr) * 2007-10-02 2011-03-23 BITRON S.p.A. Lave-vaisselle doté d'un système intégré pour contrôler des quantités d'eau
CN102901750A (zh) * 2012-10-23 2013-01-30 佛山市顺德区美的洗涤电器制造有限公司 一种洗碗机盐量信号检测电路及检测方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3441222A1 (de) * 1984-11-10 1986-05-15 Karl Winterhalter Kg, 7996 Meckenbeuren Verfahren zur steuerung einer gewerblichen reinigungsmaschine
EP0249000A2 (fr) * 1986-04-17 1987-12-16 INDUSTRIE ZANUSSI S.p.A. Machine à laver la vaisselle avec distributeur d'additif et circuit de régénération pour système adoucisseur d'eau
JPS63159749A (ja) * 1986-12-24 1988-07-02 Kurita Water Ind Ltd 硬度検出装置
EP0425815A2 (fr) * 1989-09-29 1991-05-08 MERLONI ELETTRODOMESTICI S.p.A. Machine à laver améliorée
EP0496957A1 (fr) * 1991-01-23 1992-08-05 Zanussi Elettrodomestici S.p.A. Procédé pour la régénération d'un adoucisseur d'eau dans une machine à laver
EP0517205A1 (fr) * 1991-06-06 1992-12-09 AWECO Kunststofftechnik Gerätebau GmbH & Co. KG Procédé pour l'adoucissement et appareil ménager, notamment machine à laver la vaisselle, pour la mise en oeuvre de ce procédé
DE4401411A1 (de) * 1994-01-19 1995-07-20 Licentia Gmbh Verfahren zum Betreiben einer Geschirrspül- oder Waschmaschine

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3441222A1 (de) * 1984-11-10 1986-05-15 Karl Winterhalter Kg, 7996 Meckenbeuren Verfahren zur steuerung einer gewerblichen reinigungsmaschine
EP0249000A2 (fr) * 1986-04-17 1987-12-16 INDUSTRIE ZANUSSI S.p.A. Machine à laver la vaisselle avec distributeur d'additif et circuit de régénération pour système adoucisseur d'eau
JPS63159749A (ja) * 1986-12-24 1988-07-02 Kurita Water Ind Ltd 硬度検出装置
EP0425815A2 (fr) * 1989-09-29 1991-05-08 MERLONI ELETTRODOMESTICI S.p.A. Machine à laver améliorée
EP0496957A1 (fr) * 1991-01-23 1992-08-05 Zanussi Elettrodomestici S.p.A. Procédé pour la régénération d'un adoucisseur d'eau dans une machine à laver
EP0517205A1 (fr) * 1991-06-06 1992-12-09 AWECO Kunststofftechnik Gerätebau GmbH & Co. KG Procédé pour l'adoucissement et appareil ménager, notamment machine à laver la vaisselle, pour la mise en oeuvre de ce procédé
DE4401411A1 (de) * 1994-01-19 1995-07-20 Licentia Gmbh Verfahren zum Betreiben einer Geschirrspül- oder Waschmaschine

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 12, no. 427 (P-784), 11 November 1988 & JP-A-63 159749 (KURITA WATER IND LTD), 2 July 1988, *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001018298A3 (fr) * 1999-09-03 2001-08-09 T & P Spa Systeme de reduction de la durete de l'eau et procedes de controle
DE10027844A1 (de) * 1999-12-18 2001-06-28 Aweco Appliance Sys Gmbh & Co Haushaltsmaschine
EP1723889A1 (fr) * 2005-05-13 2006-11-22 INVENSYS CONTROLS ITALY Srl Méthode et dispositif pour indiquer le besoin de remplissage de substance de régénération pour l'adoucisseur dans une machine à laver des ustensiles tel que lave-vaisselle
EP2044876A3 (fr) * 2007-10-02 2011-03-23 BITRON S.p.A. Lave-vaisselle doté d'un système intégré pour contrôler des quantités d'eau
CN101401717B (zh) * 2007-10-02 2012-06-20 比特龙有限公司 具有控制水量的整合系统的洗碗碟机
US20100229893A1 (en) * 2007-10-31 2010-09-16 Bsh Bosch Und Siemens Hausgerate Gmbh Method for operating a water-bearing domestic appliance
US9661979B2 (en) * 2007-10-31 2017-05-30 BSH Hausgeräte GmbH Method for operating a water-bearing domestic appliance
CN102901750A (zh) * 2012-10-23 2013-01-30 佛山市顺德区美的洗涤电器制造有限公司 一种洗碗机盐量信号检测电路及检测方法
CN102901750B (zh) * 2012-10-23 2015-11-25 佛山市顺德区美的洗涤电器制造有限公司 一种洗碗机盐量信号检测电路及检测方法

Also Published As

Publication number Publication date
ITTO950361A1 (it) 1996-11-09
IT1279192B1 (it) 1997-12-04
ITTO950361A0 (it) 1995-05-09
EP0741990A3 (fr) 1997-01-08

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