WO2006059302A2

WO2006059302A2 - A washer / dryer and a control method thereof

Info

Publication number: WO2006059302A2
Application number: PCT/IB2005/053999
Authority: WO
Inventors: Aylin Akova Ersoy; Zehra Ulger
Original assignee: Arcelik Anonim Sirketi
Priority date: 2004-12-01
Filing date: 2005-12-01
Publication date: 2006-06-08
Also published as: WO2006059302A3

Abstract

This invention relates to a washer/dryer (1) and a control method thereof wherein it is accomplished that redundant water and energy consumption are precluded by minimizing negative aspects in the washing performance that may stem from inadequate or excessive water intake by effectively considering all parameters in the washing medium affecting water intake process.

Description

Description A WASHER / DRYER AND A CONTROL METHOD THEREOF

[001] This invention relates to a washer / dryer and a control method thereof wherein means are provided to determine the amount of intake water by measuring the surface tension value.

[002] In washer/dryers, particularly in washing machines, water intake process is realized before the heater is activated during the wetting process where the laundry is first wetted and the cold washing process initiates. The water intake process is controlled with respect to the measurement of the water level inside the washing tank by means of level and / or pressure sensors. The water level and reading times for said levels are determined according to the washings realized with detergents. For instance, in some applications in the current state of the art, by checking the water level 4 times in a 10 minute period by using a level sensor, water is checked whether it has reached the desired level and washing process initiates at the end of the mentioned period. However, water intake process is considerably affected by changes in the amount and type of the laundry, the amount of detergent, the amount and type of surfactant material comprised by the detergent. Thereby, the realization of water intake process by solely using a level sensor causes the effect of detergent dependent factors to be ignored.

[003] Particularly, one of the main functions of the surfactant material which is one of the components of the detergent is to make sure that laundry is wetted more effectively by decreasing the surface tension value of the water. In relation to the amount and type of the surfactant material comprised by the detergent, the surface tension of the washing solution formed by the water and detergent mixture and accordingly the wetting property of the laundry and thereby the water absorbing capacity and speed of the laundry changes.

[004] Depending on user preferences, various detergent types may be utilized in washing machines. As detergents available in the market do not have standard properties, the amount and type of surfactant material in the content also shows a variety. For this reason, the amount and speed of the wetting of laundry changes, wherein water consumption and accordingly energy and washing performance are directly affected.

[005] Accordingly, in washer/dryers, various applications are available where surface tension value is measured.

[006] In the current state of the art, in German Patent Application 10022863, a description is given of an embodiment utilized in washing machines wherein means are provided both to detect the water level and to measure the surface tension.

[007] In the current state of the art, in the German Patent Application 10025430, a de- scription is given of a washing machine which comprises a mechanism measuring the pressure and surface tension values.

[008] In the current state of the art, in the United States Patent Document 5405606 and in the German Patent Applications 19529787, 3303939, a description is given of an application wherein detergent dosing and rinsing control are realized in washer/dryers by means of surface tension measurement.

[009] The object of the present invention is the realization of a washer/dryer wherein means are provided to determine the amount of intake water correctly by measuring the surface tension.

[010] The washer/dryer designed to fulfill the objectives of the present invention is illustrated in the attached figures where:

[011] Fig.l - is the schematic view of a washer/dryer.

[012] Fig.2 - is a flow chart of the control method of a washer/dryer.

[013] Elements shown in figures are numbered as follows:

1. Washer/dryer

2. Washing tank

3. Drum

4. Level sensor

5. Surface tension sensor

6. Heater

7. Cleaning agent box

8. Hose

[014] The washer/dryer (1), the object of the present invention, comprises a washing tank

(2), a drum (3) which is positioned inside the washing tank (2) and in which laundry is placed, a cleaning agent box (7) in which cleaning agents such as detergent, softener etc. are placed to be mixed with the water taken from the network, a hose (8) whereby the mixture formed by the water and cleaning agent is transferred to the washing tank (2), a heater (6) located between the drum (3) and the washing tank (2) whereby the water-cleaning agent mixture is heated, a level sensor (4) whereby the level of the said mixture is measured and, a surface tension sensor (5) which is positioned between the washing tank (2) and the drum (3) and whereby the surface tension of the mixture inside the washing tank (2) is measured during the wetting process where the laundry placed into the drum (3) is first wetted with the mentioned mixture at the beginning of the washing step (Figure 1).

[015] The surface tension sensor (5) determines when to activate the level sensor (4) and so to start the water intake process and the washing process. By measuring the surface tension value of the mixture by the surface tension sensor (5), it is achieved to start the water intake process and the washing process as the level sensor (4) is activated after the laundry has completely soaked by absorbing the mixture composed of water and cleaning agent and after cleaning agents inside the mentioned mixture are solved in water.

[016] In the washer/dryer (1), the object of the present invention, the surface tension sensor (5) and the values measured by this surface tension sensor (5) are controlled by means of a control method explained below (Figure 2).

[017] In the control method, the object of the present invention, water is taken from the network to the cleaning agent box (7) where cleaning agents such as detergent, softener etc. are placed, up to a safety level completely covering the heater (6) and, the mixture composed of cleaning agents inside the cleaning agent box (7) and water that blends with these cleaning agents is transferred to the interior of the washing tank (2) via the hose (8) located between the cleaning agent box (7) and the washing tank (2) (101).

[018] Wetting process is realized by rotating the drum (3) around its own axis for a certain period of time, preferably for three minutes, wherein both laundry inside the drum (3) is wetted by the mixture by being moved and the surface tension value of the mixture is reduced by increasing the amount of cleaning agent solved in water (102).

[019] Whereas some portion of the mixture is absorbed by the laundry as a result of wetting procedure, the other portion accumulates at the bottom of the washing tank (2). By means of the surface tension sensor (5) positioned between the washing tank (2) and the drum (3), surface tension values of the mixture which is not absorbed by the laundry exposed to wetting process and accumulates at the bottom of the washing tank (2) are measured preferably with dynamic method (103).

[020] The surface tension value (a) measured by the surface tension sensor (5) is compared to the threshold surface tension value (b) for the cleaning agent solutions which is predetermined by the manufacturer (104). In the step where the surface tension values (a and b) are compared (104), if the measured surface tension value (a) is larger than the threshold surface tension value (b) (a > b), it is checked whether the time (tl) determined by the manufacturer is reached (105), if it is not reached, by deciding that cleaning agent is not completely solved in water and that laundry is not completely wetted it is proceeded with the step (102) where the wetting process is realized. Thereby, by moving the laundry inside the drum (3), it is achieved to wet the laundry with the mixture again and to increase the amount of cleaning agent solved in water. In the step where the surface tension values (a and b) are compared (104), if the measured surface tension value (a) is smaller than the threshold surface tension value (b) (a < b) or when the time predetermined by the manufacturer is expired (t > tl) (105), water is taken in by proceeding with the next step namely the water intake process even if the surface tension value of the mixture at the bottom of the washing tank (2) does not reach a certain value (106). [021] During the water intake process (106), the level of the water (hi) taken into the washing tank (2) is continuously compared to the values sensed by the level sensor (4) (107), and when the level of the water (hi) taken into the washing tank (2) reaches the desired water level (h2) (hi > h2), water intake process stops (108), washing process initiates (109). Water intake process continues until the intake water level (hi) reaches the desired water level (h2).

[022] By means of the washer/dryer and the control method thereof, the objects of the present invention, it is accomplished to completely wet the laundry by absorbing the mixture composed of water and cleaning material and to complete the water intake process and to proceed with the washing step as the level sensor (4) is activated after cleaning materials inside the mixture are solved in water. Thereby, it is ensured that redundant water and energy consumption are precluded by minimizing negative aspects in the washing performance that may stem from inadequate or excessive water intake by effectively considering all parameters - the type and amount of the laundry, the type and amount of the detergent and the type and amount of the surfactant material in the content of the detergent - in the washing medium affecting water intake process.

Claims

[001] A washer/dryer (1) comprising ; a washing tank (2) ; a drum (3) which is positioned inside the washing tank (2) and in which laundry is placed ;a level sensor (4) whereby the level of the mixture which is transferred into the washing tank (2) and is composed of cleaning agents such as detergent, softener etc. and water is measured, and characterized by a surface tension sensor (5) which is positioned between the washing tank (2) and the drum (3) and whereby the surface tension of the mixture inside the washing tank (2) is measured during the wetting process where the laundry placed into the drum (3) is first wetted with the mentioned mixture at the beginning of the washing step and whereby the level sensor (4) is activated in order to proceed with the water intake process and washing process after the laundry is completely soaked by absorbing the mixture composed of water and cleaning material and after cleaning materials inside the mixture are solved in water.

[002] A washer/dryer (1) as described in Claim 1, characterized by a surface tension sensor (5) whereby the surface tension value (a) is measured and the level sensor (4) is activated in order to proceed with the water intake process and the washing process if the measured surface tension value (a) is smaller than the threshold surface tension value (b) for cleaning agent solutions, predetermined by the manufacturer.

[003] A control method for a washer/dryer (1) as described in any of the above Claims, comprising following steps ;the mixture is transferred to the interior of the washing tank (2) (101) ; wetting process is realized by rotating the drum (3) around its own axis for a certain period of time (102), by means of the surface tension sensor (5), surface tension value (a) of the mixture which is not absorbed by the laundry exposed to wetting process and accumulates at the bottom of the washing tank (2) are measured (103); the surface tension value (a) measured by the surface tension sensor (5) is compared to the predetermined surface tension value (b) (104) ;if the measured surface tension value (a) is larger than a certain value (b) (104), it is checked whether the time determined by the manufacturer is expired (t > tl) (105); if the time determined by the manufacturer is not expired, it is proceeded with the step (102) where the wetting process is realized; if the surface tension value (a) measured by the surface tension sensor (5) is equal to or smaller than the desired surface tension value (b) (104) or when the time determined by the manufacturer is expired (t > tl) (105), water to be used in the washing process is taken into the washing tank (2) by measuring the level with the level sensor (4) (106) ;the level of the water (hi) taken into the washing tank (2) is compared to the values sensed by the level sensor (4) (107); water intake process stops when the level of the water (hi) taken into the washing tank (2) reaches the desired water level (h2) (hi > h2) (108); washing process initiates (109).