FR2734502A1 - WASHING AND CLEANING METHOD AND DEVICE - Google Patents

Abstract

A washing and cleaning method includes simultaneously applying infrasonic and ultrasonic vibrations to the liquid containing the items to be washed or cleaned. The frequencies are advantageously selected in the range of 10 to 90 Hz and 15 to 25 kHz respectively. The infrasonic and ultrasonic vibrations are preferably transmitted by means of a flexible diaphragm contacting the liquid containing the items to be washed. The washing and cleaning device has a housing (10) containing sound wave transmitting means (11, 12) with a transmitting diaphragm (13, 14), such as loud-speakers. The diaphragm is impervious and contacts the liquid when the device is immersed therein. The frequencies are advantageously selected in the above-mentioned ranges.

Description

WASHING AND CLEANING METHOD AND DEVICE
The subject of the invention is a method of washing and cleaning, by emission of ultrasound in a liquid containing the objects to be washed or cleaned.

 It also relates to a washing and cleaning device, intended to be immersed in a liquid containing the objects to be washed or cleaned, comprising a housing containing means for emitting acoustic waves having an emitting membrane.

 It applies to the field of washing and cleaning of soiled or stained objects and in particular of textiles.

 An ultrasonic washing and cleaning aid device is described in the utility certificate DE-U90 02 289. It is suggested in this document to have an acoustic wave emitter, electrical supply members in a sealed housing and control elements. It is in particular proposed to use as a transmitter of acoustic waves a loudspeaker, excited by a device that transmits ultrasonic frequencies.

 This device has the following drawbacks. The mere emission into the ultrasonic cleaning liquid does not ensure optimal washing and cleaning. The device in question has a low efficiency, due to frequency and energy losses in the ultrasound path from the emitting device to the liquid containing the objects to be cleaned, through the sealed housing. To improve efficiency, it is necessary to increase the power consumption of the device, which requires an external power supply from the network.

 Another known washing and cleaning device consists of a sealed ball, on the inner wall of which is fixed an electric motor. On the axis of the motor is placed an eccentric mass. Means for supplying the motor are also provided, by accumulators arranged in the ball, or by the network.

The motor rotates with a rotation speed of between 8000 and 15000 rpm, which leads to emission of waves having a frequency in the range of 133 to 250 Hz.

 This device also has drawbacks. It does not provide effective washing and cleaning, due to the choice of frequency range.

 The axis of the motor is subject to rapid wear due to the eccentricity of the driven mass. The electric power necessary to drive the motor is important: this easily leads to heating of the accumulators, and if necessary to a gas emission.

In addition, the autonomy of the device is quite reduced.

 The presence of moving parts in the device makes it necessary to provide for a mechanical separation in the ball, between the motor and its mass on the one hand, and the accumulators and the internal wiring on the other hand: this makes it possible to avoid tearing of the cables by the eccentric mass, and limits the risks linked to the emission of gas by the accumulators to charge or discharge. The structure of the ball is therefore quite complex.

 The performance of this device is quite poor. In fact, the vibrations generated by the rotation of the eccentric mass are transmitted to the liquid surrounding the device via the wall of the ball.

The frequency restitution is linked to the characteristics of the material of the ball, which in any event causes a loss in frequency. Like the device, due to the necessary choice of the material of the ball, floats and has a non-submerged part, it produces a significant noise. The presence of a non-submerged part further reduces the yield.

 Finally, in this known device, the temperature inside the ball in operation can reach values of the order of 110 ° C. This, in addition to the loss of energy, poses problems for the operation of the engine and of the Accumulators.

 The invention solves these problems.

 It ensures effective washing and cleaning, using a device with great autonomy, a simple structure, with good acoustic performance.

It is very reliable and not subject to wear.

 The invention also solves the new problems associated with starting and stopping the cleaning device.

 The invention provides a method of washing and cleaning, by emission of ultrasound in a liquid containing the objects to be washed or cleaned, characterized in that it further comprises the simultaneous emission of infrasound in the liquid containing the objects to be washed or cleaned.

 Advantageously, said ultrasound has a frequency between 15 and 25 kHz, and said infrasound has a frequency between 10 and 90 Hz.

 In one embodiment of the method, said infrasound and said ultrasound are emitted by means of a flexible membrane in contact with the liquid containing the objects to be washed or cleaned.

 The invention further provides a washing and cleaning device, intended to be immersed in a liquid containing the objects to be washed or cleaned, comprising a housing containing means for emitting acoustic waves having an emitting membrane, characterized in that said membrane is waterproof and comes into contact with said liquid when said device is immersed in said liquid.

 Advantageously, said means for emitting acoustic waves emit ultrasonic and infrasonic waves.

 The acoustic wave transmission means can emit ultrasonic waves having one or more frequencies between 15 and 25 kHz, and / or infrasonic waves having one or more frequencies between 10 and 90 Hz.

 In one embodiment, said means for emitting acoustic waves consist of at least one loudspeaker having a flexible waterproof membrane.

 In another embodiment, the washing and cleaning device comprises means for connection with electrodes capable of coming into contact with the liquid in which said device is immersed, said connection means controlling the emission of acoustic waves by said means for emitting acoustic waves as a function of the resistance between said electrodes.

Other advantages of the invention will appear on reading the following description of embodiments, given by way of example, and with reference to the appended figures, which show: - Figure 1 a block diagram of a device of
washing and cleaning according to the invention, - Figure 2 a block diagram of another mode of
production of a device according to the invention; - Figure 3 a more detailed diagram of the circuits of
Figure 2 device.

 The washing and cleaning device of Figure 1 comprises a sealed housing 1 which is intended to be immersed in the liquid containing the objects to be washed or cleaned. The case can be completely immersed in the liquid containing the objects; it may also be only partially submerged.

 The housing 1 contains means for emitting acoustic waves having a membrane 3. The means for emitting acoustic waves can be constituted by any type of membrane emitter capable of emitting acoustic waves. In a preferred embodiment of the invention, one or more speakers are simply used.

 According to the invention, the means for emitting acoustic waves 2 have a waterproof membrane 3, which is capable of coming into contact with the liquid containing the objects to be cleaned when the housing 1 is immersed in this liquid. The tightness of the membrane preserves the tightness of the washing device and protects the means for emitting acoustic waves as well as the other members arranged in the housing. As the membrane 3 comes directly into contact with the cleaning liquid, the acoustic waves are emitted by the means for emitting acoustic waves directly to the liquid. The invention thus makes it possible to compensate for the performance defects of known devices: in fact, the acoustic waves are not transmitted to the liquid via the housing 1, but directly by the membrane 3. This ensures good transmission without loss of energy, nor loss of frequencies.

 One of the advantages of the solution of the invention is to allow a wider choice of the characteristics of the housing 1, and in particular as regards its material and its shape: it is not necessary that the material making up the housing 1 be good transmitter of acoustic waves, nor that it has a particular shape. In fact, the only function of the housing 1 is to isolate the various organs that it contains from the liquid containing the objects to be washed or cleaned.

 The housing 1 contains energy storage means 4, such as for example accumulators or batteries. It further comprises means 5 for controlling and piloting the means for emitting acoustic waves 2. The command and piloting means 5 are connected to the energy storage means 4 and are liable to excite the means of 'emission of acoustic waves to cause the emission of ultrasound and / or infrasound, as explained below. The structure of the control and piloting means is described in more detail below.

 The device of Figure 1 operates as follows. The objects to be washed or cleaned are placed in a liquid, with if necessary a cleaning additive, for example washing powder or the like. The washing and cleaning device is immersed in the liquid. As explained above, it can be totally or only partially submerged: the main thing is that the membrane 3 of the means for emitting acoustic waves come into contact with the liquid. The washing device emits ultrasound and / or infrasound in the liquid containing the objects to be cleaned, which cause the objects to be washed. After a variable period depending on the initial state of the objects to be washed or cleaned, the device is removed from the liquid and the objects are ready to be rinsed or dried.

 The invention also relates to a washing and cleaning process by emission of ultrasound in a liquid containing the objects to be washed. The invention proposes to simultaneously transmit ultrasound and infrasound.

The simultaneous emission of infrasound and ultrasound ensures effective washing and cleaning, by the combined action of ultrasound and infrasound. Ultrasound has an action to remove dirt or soiling, while infrasound has an action to remove loose soil. The use of ultrasound at the same time as infrasound improves water resonance and promotes washing.

 Compared to known devices, the method of the invention improves the efficiency of washing and cleaning, thanks to the combination of ultrasound and infrasound.

 The ultrasound can advantageously be emitted with a frequency or frequencies included in a range from 15 to 25 kHz. The infrasound can advantageously be emitted with a frequency or frequencies included in a range going from 10 to 90 Hz.

 The results of a comparative test are given by way of example on cotton shirts previously stained with coffee, wine and strawberry jam, which are soaked in water at 400 ° C. with washing detergent ordinary.

 Washing is carried out for a period of thirty minutes, using washing and cleaning devices supplied with a current of 1 A, at a voltage of 7.2 V.

 Ultrasound alone.

 Using a device of the type described in DE-U-90 02 289, ultrasound is emitted at a frequency of 15 kHz. At the end of the test (thirty minutes), the spots are still visible. There is no change from the initial state visible to the eye.

 Ultrasound alone.

 Using a device of the type of that of FIG. 2, only ultrasound is emitted at a frequency of 15 kHz. At the end of the test (thirty minutes), the spots are still visible.

 Infrasons alone.

 Using a device of the type shown in FIG. 2, only infrasound is emitted, at a frequency of 50 Hz. At the end of the test (thirty minutes), the spots have almost disappeared, but a halo remains visible. .

 Infrasound and ultrasound.

 Using a device of the type shown in FIG. 2, infrasound is emitted at a frequency of 50 Hz and ultrasound is emitted at a frequency of 15 kHz. At the end of the test (thirty minutes), the spots have completely disappeared and no halo can be seen.

 It appears surprisingly that ultrasound alone has no effect on textile objects, in particular cotton, which are too flexible to enter into resonance. However, the combination of ultrasound and infrasound improves the resonance of the water and promotes washing efficiency.

 The method of the invention can advantageously be implemented using a device of the type described with reference to FIG. 1. If the means for emitting acoustic waves consist of a speaker, they can be made to emit simultaneously ultrasound and infrasound in the above-mentioned frequency ranges.

 Figure 2 shows a block diagram of another embodiment of a washing or cleaning device according to the invention. The device of Figure 2 comprises a housing 10. The housing 10 may have any shape; in the embodiment of Figure 2, it has a general shape of truncated ellipsoid of revolution or capsule. it consists of a material which can be freely chosen, to ensure the isolation of the organs it contains from the liquid which contains the objects to be cleaned.

Advantageously, the material of the housing resists the detergents and other additives usually used for washing and cleaning. One can thus choose as material polypropylene, or polycarbonate.

 The device of FIG. 2 comprises two means for emitting acoustic waves 11 and 12. They each have a flexible and waterproof membrane 13, 14. The assembly constituted by the housing 10 and the membranes 13, 14 of the means for emitting acoustic waves 11, 12 forms an enclosure 15 impermeable to the liquid in which the washing and cleaning device can be immersed.

 The acoustic wave emission means 11, 12 ensure the emission towards the liquid in which the ultrasonic and / or infrasonic wave device is immersed, preferably within the abovementioned frequency ranges of 15 to 25 kHz and from 10 to 90 Hz.

 They can, for example, consist of speakers with a waterproof membrane, which are commercially available. For example, loudspeakers with a diameter of 85 mm can be used with a bandwidth of 50 Hz to 20 kHz, with a flexible membrane made of GoretexS TeflonX or fiberglass.

 The use of such means for emitting acoustic waves makes it possible to obviate the drawbacks of known devices, by avoiding the problems associated with moving parts, and by limiting the temperature increases inside the washing device.

 The housing 10 comprises grids 17, 18 through which a liquid can circulate freely, which are arranged in front of the membranes 13, 14 of the means emitting acoustic waves. These grids 17, 18 provide mechanical protection of the membranes when the washing and cleaning device is immersed in the liquid containing the objects to be washed, without adversely affecting the effectiveness of the washing. The grids 17, 18 are dimensioned so as to prevent the passage of hard bodies present in the objects to be cleaned, such as buttons, clothing loops, etc., which could damage the membranes 13, 14.

 Found in the sealed enclosure 15 formed by the housing 10 and the membranes 13, 14 the electromagnets of the speakers 12 and 13, as well as means for storing electrical energy 19, connection means 20 and a control and piloting circuit 21.

 The electrical energy storage means 19 are constituted by accumulators or batteries capable of supplying the electrical energy necessary for the emission of the acoustic waves. It is possible, for example, to use commercial accumulators, or commercial batteries, of 1.2 V, connected in series so as to supply a voltage of 7.2 V, and capable of delivering a current of the order of 1 or 2 A.

 The series connection of accumulators allows a better return of electrical energy, and limits heating and wear to the charge or discharge.

 The electrical energy storage means are connected to the connection means.

 The connection means 20 perform two functions: on the one hand, they make it possible to determine when the washing or cleaning device is immersed in a liquid. On the other hand, they are likely to receive an external electrical supply.

 The connection means are connected on the one hand to the storage means 19 and on the other hand to the piloting and control means 2.

 The connection means have two electrodes 22 capable of coming into contact with the liquid in which the washing device is immersed.

 The connection means also have two pins 23 on which it is possible to connect an external power supply, for example a 12 V adapter connected to the mains, or a socket supplying automotive 12 V.

 The connection means have means for measuring the resistance between the electrodes 22, so as to determine whether or not the washing device is immersed in a liquid. When the washing or cleaning device is immersed in a liquid, the connection means 20 allow electrical energy from the storage means 19 or the pins 23 to pass to the piloting and control means 21, so as to allow the emission of acoustic waves. When the washing and cleaning device is not immersed in a liquid, the connection means isolate the control means 21 from the supply of electric power.

 This allows automatic starting and stopping of the washing device when it is submerged or emerged.

 The piloting and control means 21 convert the electrical energy received from the connection means 20 into a signal capable of exciting the means for emitting acoustic waves 11 and 12. The structure of the piloting and command is explained in more detail with reference to Figure 3.

 The device of Figure 2 therefore allows washing and cleaning of objects contained in a liquid in which it is immersed. Of course, it is possible to modify the various elements of the device described.

Thus, the energy storage means can be omitted to be satisfied with an external supply; in such a case, the electrodes 22 can be removed from the connection means 20, so that the device starts and stops depending on whether or not there is a power supply on the terminals 23. One could also remove the pins 23 and transform the electrodes 22 into a simple switch, for example in the case of a disposable device.

 FIG. 3 shows a more detailed diagram of the electrical circuits of the device of FIG. 2. We find in FIG. 3 the connection means 20, the electrodes 22, the pins 23 and the piloting and control means 21. Appear on the Figure 3 the link 24 connecting the connection means 20 to the energy storage means 19, the link 25 connecting the connection means 20 to the control means 21, as well as the links 26 and 27 connecting the control means 21 to the means acoustic wave transmitters 11 and 12 in FIG. 2. These various connections are represented symbolically and are in fact constituted by suitable electrical conductors.

As explained above, the connection means receive an external power supply on the pins 23, and on the link 24 the current coming from the energy storage means 19. Depending on the resistance between the electrodes 22, the connection means deliver or not on link 25 a continuous electrical signal, at a voltage of 6 to 12 V with an intensity of 500 mA to 2
A. A simple 12 V relay can be used in the connection means to control the stopping and starting of the device.

 The control means 21 include an ultrasonic oscillator 30, an infrasonic oscillator 31, a mixer 32, and a power amplifier 33. All of these elements are supplied by the electrical signal coming from the connection means 19 via the link 25, as appears in figure 3.

 The ultrasonic 30 and infrasonic oscillators 31 each transmit an electrical signal to the mixer 32 in the respective frequency ranges mentioned above. By way of example, the oscillators 30 and 31 can be produced using circuits of the NE 555 type sold by the Harris company.

 The mixer 32 receives the signals from the oscillators 30 and 31 and transmits to the amplifier 33 a mixed signal corresponding to a combination of the two signals. Mixer 32 can be produced conventionally from commercial components.

 The power amplifier 33 receives the signal from the mixer 32 and transmits the drive signals.

to the loudspeakers 11 and 12 on the links 26 and 27. Advantageously, the amplifier 33 does not content itself with providing an amplified signal between 0 V and a maximum voltage Vmax, between 6 and 12 V depending on the power supply , but provides an amplified signal between -Vmax and + Vmax. This is for example possible using a Darlington diode bridge, or even using a 4-channel L293E push-pull interface (symmetrical amplifier) from the company Thomson, forming an H-bridge, and Texas company transistors 2907
Instruments.

 Other conventional passive components are used for the various circuits of FIG. 3, which are not described in more detail.

 Of course, the present invention is not limited to the embodiments described and shown, and it is capable of numerous variants accessible to those skilled in the art without departing from the spirit of the invention. 'invention. Thus, the emission of ultrasound and infrasound can be simultaneous and occur on the same means of emission of acoustic waves, as described with reference to the figures; "simultaneous" should also be understood to mean the emission of ultrasound and infrasound on different transmission means, or else the time multiplexing of infrasound and ultrasound on one or more transmission means. One could also use a single speaker with a larger diameter, for example of the order of 120 mm, in a substantially cylindrical housing.

Claims (10)

CLAIMS.  1.- Washing and cleaning process, by emission of ultrasound in a liquid containing the objects to be washed or cleaned, characterized in that it further comprises the simultaneous emission of infrasound in the liquid containing the objects to wash or clean.  2.- washing and cleaning method according to claim 1, characterized in that said ultrasound has a frequency between 15 and 25 kHz.  3.- washing and cleaning method according to claim 1 or 2, characterized in that said infrasound have a frequency between 10 and 90 Hz.  4.- washing and cleaning method according to one of claims 1 to 3, characterized in that said infrasound and said ultrasound are emitted by means of a flexible membrane in contact with the liquid containing the objects to be washed or cleaned .  5.- Washing and cleaning device, intended to be immersed in a liquid containing the objects to be washed or cleaned, comprising a housing (1; 10), containing means (2; 11, 12) for emitting acoustic waves having an emission membrane (3; 13, 14), characterized in that said membrane (3; 13, 14) is waterproof and comes into contact with said liquid when said device is immersed in said liquid.  6. Washing and cleaning device according to claim 5, characterized in that said means (2; 11, 12) for emitting acoustic waves emit ultrasonic and infrasonic waves.  7.- washing and cleaning device according to claim 5 or 6, characterized in that said means (2; 11, 12) for emitting acoustic waves emit ultrasonic waves have one or more frequencies between 15 and 25 kHz.  8.- washing and cleaning device according to one of claims 5 to 7, characterized in that said means (2; 11, 12) for emitting acoustic waves emit infrasonic waves have one or more frequencies between 10 and 90 Hz.  9. Washing and cleaning device according to one of claims 5 to 8, characterized in that said means for emitting acoustic waves consist of at least one loudspeaker (2; 11, 12) having a flexible waterproof membrane (3; 13, 14).  10.- washing and cleaning device according to one of claims 5 to 9, characterized in that it comprises connection means (20) with electrodes (22) capable of coming into contact with the liquid in which said device is immersed, said connection means (20) controlling the emission of acoustic waves by said acoustic wave emission means (2; 11, 12) as a function of the resistance between said electrodes.