ES2378763T3 - System to reduce water hardness and corresponding control procedures - Google Patents

Abstract

System for reducing water hardness as required for operation of utilizer apparatus, in particular a household washing machine, using resins (R) which reduce their own softening capacity in function of the quantity of water treated. The system employs a detection device (1) of the resins state comprising a magnetic element (13) capable of varying its own position in function of the volume change of a given quantity of resins (10), and means (18) for detecting the position of said magnetic element (13). Detection operations performed by said device (1) are used for ensuring efficient control of the regeneration and washing phases of the resins being used by the system.

Description

System to reduce water hardness and corresponding control procedures.

The present invention relates to a device for reducing water hardness as required for the operation of a use apparatus, in particular a domestic washing machine, as well as a device for detecting the state of resins used for softening. and corresponding control procedures.

As is known, domestic washing machines that use water, in particular dishwashers, are equipped with a washing water softening apparatus intended to reduce the degree of water hardness and avoid possible calcareous deposits. Such a device is also called a softener. As is known, the softener comprises a container with ion exchange resins or a similar substance (referred to below as resins for reasons of greater simplicity) for softening the wash water. However, after a certain period of use the resins are depleted, depending on the amount of water treated and its degree of hardness (obviously, the higher the degree of hardness of the water, the faster the depletion of the resin) ; As a result, when the resins are depleted, the water flowing through them will maintain substantially the same hardness it had at its entrance.

In order to avoid this inconvenience, a resin regeneration phase is provided consisting of introducing a solution of water and salt (NaCl) into the resin container, the salt being contained in a special tank belonging to the softening system of the wash machine; practically, a predetermined amount of water, dosed in the usual manner, is supplied to said tank to obtain a corresponding amount of water-salt solution so that it flows through the resin container and regenerates them.

In most of the known solutions, this phase is usually executed in each wash cycle, requiring that a considerable amount of salt is frequently introduced by the user into the appropriate container; In addition, this obviously also requires greater water consumption.

In order to reduce the waste of salt and water, some washing machines are equipped, as is known, with water hardness sensors that cause the resin regeneration phase to begin only when it is detected that the water hardness is exceeding a certain threshold due to the exhausted ability of the resins to soften the water; said sensors usually measure the resistivity of the treated water and a control system will activate

or not the regeneration of resins based on the information obtained.

However, even if the water hardness is regularly reduced, it may possibly happen that a slight calcareous layer is deposited on the sensors before activating the regeneration, thus altering the detection of the degree of water hardness due to an increased resistivity produced by the limestone

In addition, such a system that directly detects the degree of water hardness will only indirectly perceive the state of efficiency of the resins; therefore, the regeneration of resins can also be activated in those cases in which it is not yet required.

Since, as the resins gradually deplete their degree of efficiency, their volume decreases, the resource of detecting this volume change during the depletion phase is also known to determine the beginning of a regeneration process.

Document DE-A-3831811 refers to a method and an apparatus for controlling the regeneration of water softening units by exploiting the properties of the exchange material to experience a reduction in volume during water softening and an increase in volume during regeneration. . Regeneration begins when the exchange material, which is in a container on which a bellows is attached, assumes a small volume. A regeneration valve is actuated by means of a drive rod through which a regeneration brine is passed through the exchange material. When the volume of the material increases during regeneration, the bellows expands and the regeneration valve is closed by means of the stem, after which additional water softening can be carried out.

EP-A-0154278 refers to a hardness sensor for a water softener comprising a membrane that is continuously tied on the free surface of the resins, and a piston that is continuously positioned on a resin fill, having the piston a specific weight considerably greater than that of water and being located on the membrane.

Document EP-A-0919178, in the name of the same applicant of the present patent application, refers to a device for reducing water hardness, suitable for use in a domestic washing machine, in particular a dishwasher, comprising a container within which ion exchange resins are housed that reduce the degree of hardness of the water that licks them, and means to regenerate the softening efficiency of said resins. Within said container are arranged sensor means to check the status of said resins and,

Depending on the physical state of said resins, detect the degree of depletion of said resins.

However, even when these systems are capable of accurately detecting the state of exhaustion of the resins and starting a relevant regeneration phase, they do not allow obtaining other parameters and useful information, such as a stop of the regeneration phase, too much salt or lack. of salt in the water softener, or relevant data to start and / or perform and stop the resin washing phase.

For example, according to the known technique and regardless of the procedure used to detect the state of exhaustion of the resins, the resin regeneration phase is always carried out with a quantity of water previously determined and supplied to the salt container; therefore, the duration of such phase and the amount of water used for that purpose are not directly controllable depending on the achievement of the real restoration of the efficiency of the resins; in other words, the regeneration phase in some cases may be longer or use more water than is really required to obtain a complete regeneration of resins; On the contrary, in other cases, the duration of the regeneration phase or the amount of water used for that purpose may not be sufficient to determine a complete restoration of resin efficiency.

The same applies to the resin washing phase, required after a regeneration phase, which, according to the known technique, has a fixed duration or is obtained with a substantially predetermined amount of water.

In practice, in fact, a washing of resins of this type is carried out by supplying a certain amount of water from the distribution network to the washing tub of the machine and at the same time maintaining a working discharge pump; thus, the water from the distribution network flows to the resin container, removing any remaining salt from the resins also due to the previous activation phase, and then flows into the tub for immediate discharge.

Said washing phase is generally carried out by opening a solenoid valve for a time (predetermined in the design phase) which allows a quantity of new water considered sufficient to remove salt residues to flow through the resins; In some solutions, in order to ensure a resin washing as correct as possible, several subsequent washing phases are provided.

Therefore, as it can be observed, according to the known technique, the duration of the resin washing phase and the amount of water used for that purpose do not depend directly on whether a complete and actual resin washing is achieved; in other words, in some cases, such a phase could last longer or more water could be used than is actually required for resin washing; On the contrary, in other cases, the duration of such a phase or the amount of water used for that purpose may not be sufficient for proper resin washing.

The objective of the present invention is to overcome the above disadvantages and to provide a system to reduce the degree of water hardness as required for the operation of the appliance, in particular a domestic washing machine, as well as a detection device and procedures. of control of the same that allow the detection, in a simple, easy, reliable, cheap and direct way, of the state of exhaustion of a water softening material and an efficient control of its regeneration processes.

In this context, an objective of the present invention is to provide such a system in which the resin regeneration phase can be controlled directly, that is, after achieving the real restoration of the resin efficiency.

A further objective of the present invention is to provide such a system in which the resin washing phases can be directly controlled, that is, after achieving a complete real resin washing. Another object of the present invention is to provide a method for detecting the degree of depletion of the resins, a procedure for controlling the phase of regeneration of the resins and a method for controlling the phases of resin washing, which are reliable and advantageous.

A further objective of the present invention is to provide the manner in which the above systems and procedures can be automatically managed by means of an electromechanical programmer or electronic control device.

In particular, the present invention is directed to the solution of the technical problem concerning the proper functioning of the device for detecting the state of resins comprising the container containing the sample resins and their complete regeneration and / or washing when the process is carried out. regeneration and / or washing of all resins contained in the softening device.

Therefore, the objective of the present invention is to describe a particularly advantageous solution of such a system and / or device and / or method capable of achieving the above purposes.

The foregoing objective according to the present invention is obtained with a system to reduce the degree of water hardness as required for the operation of a use apparatus, in particular a domestic washing machine, as well as with the control procedures incorporating the characteristics of the appended claims, which form an integral part of the present invention.

Other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings, which are provided by way of non-limiting example and in which:

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Figure 1 schematically shows a vertical section of the front view of a first embodiment of a device for detecting the state of the resins of a water softener according to the present invention;

10 - Figure 2 schematically shows a vertical section of the side view of a device for detecting the state of the resins of a water softener according to the present invention;

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Figure 3 schematically shows a vertical section of the front view of a second embodiment of a device for detecting the state of the resins of a water softener according to the present invention;

15 - Figure 4 schematically shows a partial perspective view of an embodiment of a device for detecting the state of the resins of a water softener according to the present invention;

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Figure 5 schematically shows a cross section of an embodiment of a device for detecting the state of the resins of a water softener according to the present invention;

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Figure 6 schematically shows the position and hydraulic connection of the device for detecting the state of the resins of a water softener according to the present invention;

25 - Figure 7 shows the operating diagram of a first embodiment of a device for detecting the state of the resins of a water softener according to the present invention;

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Figure 8 shows the operation diagram of a second embodiment of a device for detecting the state of the resins of a water softener according to the present invention;

30-Figures 9 and 10 show partial wiring diagrams of a first embodiment of a device for detecting the state of the resins of a water softener according to the present invention; Y

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Figure 11 schematically shows a vertical section of the front view of an embodiment of the device 35 for detecting the state of the resins of a water softener according to the present invention.

In Figure 1, the number 1 indicates, as a whole, a device for detecting the state of resins used in a system to reduce the degree of water hardness according to the present invention, as a first possible embodiment.

40 The number 2 indicates the body of the device 1, which has a cylindrical hollow part 3 and an annular plate 4. The cylindrical hollow part 3 has three sections with an inner diameter different from each other, indicated with 3A, 3B and 3C, respectively . Section 3B has a smaller diameter with respect to both sections 3A and 3C.

From plate 4, two cylindrical sleeves 5 and 5 ’that deviate vertically downwards are substantially divided at mid-height by a wall 6 and 6’; walls 6 and 6 ’have a central hole indicated with 7 and 7’, respectively.

The number 8 indicates a hollow column or a similar tubular element that is closed at one end by a wall 8A; in column 8 a plate 9 is located near the closed end.

50 Column 8 is inserted into section 3A of the cylindrical part 3 of the body 2, where its insertion is stopped by striking the plate 9 against the plate 4 of the body 2. Between column 8 and section 3A of the cylindrical part 3 there are common hydraulic sealing means, such as an annular gasket, not shown for reasons of simplicity.

55 The number 10 indicates sample resins and the number 11 a moving element. The number 11A indicates the base of the mobile element 11, which is substantially in the form of a hollow cylinder closed at one end, the outer diameter of which is intended to be married and slid into the inside diameter of the column 8 and into the inside diameter of the section 3B of body 3; the diameter of the section 3B is equal to the inside diameter of the column 8. The number 12 indicates a rod having at one end a cylindrical extension 12A with a diameter greater than that of

60 the rod itself, suitable for insertion into the inner part of the base 11A. In addition, the rod 12 is divided into two parts indicated with 12B and 12C, respectively, by a plate 12D; the part 12B has a vertical cylindrical recess 12E between the plate 12D and the end 12A.

The cylindrical recess 12E is connected outside through a hole 12F perpendicular to it. The extension 12A of the rod 12 has a round recess suitable for containing a magnetic element 13, such as a permanent magnet.

The magnetic element 13 is held in position by a washer 13A located between the bottom wall of the base 11A and the bottom of the part 12A of the rod 12 when the latter is fastened to the base 11A.

The bottom wall of the base 11A of the movable element 11 and the bottom wall 8A of the column 2 have grooves 14 ’and 14 whose size is such that they allow water to flow through, but not the resins.

The part 12C of the rod 12 has a ferromagnetic core N inside and is inserted into a coil 35, sliding freely.

The coil 35 is fastened, for example, by means of screws to a closing cover 36 of the upper end of the cylindrical hollow part 3 of the body 2.

The number 15 indicates, as a whole, an element capable of sliding on the outer wall of the cylindrical part 3 of the body 2; No. 16 indicates the body of the sliding element 15, which has a threaded pin 17.

The number 18 indicates a relay with lamellae enclosed in a glass housing filled with inertial gas, commonly called and in what follows the reed relay, which can be activated by an external magnetic field. The reed relay 18 is inserted vertically into the body 16 of the sliding element 15 in a position where it is substantially close and parallel to the outer wall of the cylindrical part 3 of the body 2.

Reed relay 18 is electrically connected outside by means of a common connector.

The number 19 indicates a nut to fasten the sliding element 15 to the wall 6 of the cylindrical bushing 5 and the number 20 indicates a spring that strikes against the wall 6 of the sleeve 5 and against the body 16 of the sliding element 15 to keep the sliding element 15 in a position defined by the degree of tightening of the nut

19.

The tightening and / or loosening of the nut 19 on the pin 17 causes an upward or downward movement with reference to figure 1 of the sliding element 15 and, consequently, a change of position of the reed relay 18 for calibration purposes of the device, as best described below. In order to guide such sliding, the lateral ends of the body 16 have an edge 21 whose shape allows its insertion into a complementary seat 22 of the body 2, acting as a guide (see Figure 5).

With reference to Figure 2, the numbers 37 and 38 indicate a first projection and a second projection symmetrically opposed at the upper end of the cylindrical hollow part 3 of the body 2 perpendicular to it.

The projections 37 and 38 have inside a conduit indicated with 39 and 40, respectively, which hydraulically connects the exterior of the section 3C of the cylindrical part 3 with its interior; thanks to the hole 12F and the recess 12E in the rod 12, the section 3C is hydraulically connected with the inside of the column 8 containing the resins 10.

The projection 37 has an external configuration suitable for connection to a water supply connector for the water that comes from the distribution network through a water softening device.

The projection 38 is hydraulically connected through the conduit 40 to the outflow tank of the wash water softener to regenerate the softening resins.

In the conduit 40, a check valve 42 is inserted to prevent water from the distribution network and flowing through the conduit 39 from reaching the salt tank through the conduit 40.

The number 36 indicates the closing cover of the upper side of the part 3 of the body 2, which has a hole 41 in the center so that the part 12C of the rod 12 passes through it.

The closing cover 36 is fixed to the upper side of the part 3 of the body 2 by means of screws V.

The number 35 indicates the coil attached to the closure cap 36 by common means, such as screws or coupling teeth, which internally support the part 12C of the rod 12 with the ferromagnetic core N inside it.

When the coil is electrically powered, a magnetic field is produced within it, which attracts within it the ferromagnetic core N located in section 12C of the rod 12, as is commonly known, with a consequent upward movement of the moving element 11 ; when the coil is not fed, the ferromagnetic core N is no longer retained by the magnetic field and, due to its weight and the action of a spring 43 located inside the coil, descend by itself until the mobile element 11 rests on the resins 10 contained in column 8.

In order to avoid that the ferromagnetic core N, after being released by the coil 35, can reach a position where it can no longer be removed by the fed coil 35, it is envisaged that the insertion of the

moving element 11 in column 8 is stopped by the plate 12D when it hits the step resulting from the difference in diameter between part 38 and section 3C of body 3.

However, the insertion of the mobile element 11 into the column 8 is such that it is higher than a maximum volume reduction of the resins 10 in their depletion phase.

The present invention is based on the knowledge of two considerations.

A first consideration is that normal resins used as known to reduce water hardness tend to change their volume when they become depleted, the phenomenon of which occurs during normal operation of the softening device.

A second consideration, reached by the authors of the present invention, is that the volume of the resins themselves may also undergo changes due to particular conditions of the concentration of sodium ions (Na +) in the water solution that moistens them.

Such a phenomenon is explained both by the configuration and by the composition of the resins. Quite schematically, the resins are typically formed by granules or small beads, each of which comprises a structure of polystyrene chains, substantially wrapped between them like a ball; the various polystyrene chains are tied to each other by means of smaller divinylbenzene chains, at which sites (SO4-) are available where ions can reside. The inventors have found that the polystyrene structure of the resin beads substantially forms a semipermeable membrane that is capable of retaining a portion of the Na + ions contained in the water-salt solution that moistens them during the regeneration phase.

Also, the remaining part of the Na + ions that remain outside said membrane tend to enter the structure, but in vain; Since it cannot enter the resin pearl structure, the osmotic pressure exerted by such Na + ions on the anterior membrane will compress the pearl and reduce its volume.

According to the present invention, such a phenomenon of resin volume reduction can be exploited when immersed in a highly concentrated saline solution, in order to efficiently control the resin regeneration process.

For information purposes only, such volume reduction is about 10-11% with a water solution containing 100 g / l of sodium chloride.

When the resins are in their natural or virgin state, they already contain sodium (Na +) ions to be exchanged with calcium (Ca ++) and magnesium (Mg ++) ions contained in the wash water.

Therefore, according to the present invention, the preparation of the device 1 and the sample resins to be introduced in column 8 (together with the magnetic element 13 and the reed relay 18 mounted on the sliding element 15), forming a sensor to detect The state of the resins provides the following procedure.

The amount of sample resins 10 is dosed and entered in column 8; It should be noted that, before being introduced into column 8, the sample resins 10 are preferably subjected to a typical operating cycle, ie exhaustion - regeneration - washing. Preferably, the sample resins 10 will consist of beads with a diameter greater than the resin beads contained in the softener device of the washing machine; In addition, its diameter will be as consistent as possible.

The use of beads with a larger diameter is justified in that the water flow is improved with a better subsequent spraying of all the sample resins and prevents leakage of resin beads between the inner wall of the column 8 and the moving element 11; The advantage obtained by its consistent diameter is to ensure an ion exchange and a more homogeneous volume change.

It should also be noted that the sample resins do not necessarily require the same type as that used in the softener, but they must be of a type very suitable for device 1.

The column 8 is inserted into the hollow cylindrical part 3 of the body 2, where the plate 9 of the column 8 will strike against the plate 4 of the body 2.

Next, the movable element 11, with the magnetic element 13 inserted in the seat of the extension 12A of the rod 12, is inserted in the column 8; the movable element 13 will take a position against the upper surface of the sample resins 10 previously introduced in column 8.

The upper end of the cylindrical part 3 is then closed with a cover 36, which is attached to it by means of screws as is commonly known, bearing in mind that the rod 12 has to pass through the hole 41 of the

center of the lid 36.

Now, the sliding element 15 is assembled on the outer wall of the cylindrical part 3 of the body 2, inserting the threaded spike 17 into the hole 7, after having previously mounted the spring 20 on the threaded spike 17; the sliding element 15 is then fastened to the wall 6 ’of the cylindrical sleeve 5’ by means of the nut 19 threaded on the pin 17.

Now, with all components assembled, device 1 is calibrated according to the following procedure; the operation is performed with the device upright, that is, placed in its working position; such working position with the water supply from top to bottom has been selected to improve the operation of the device.

In fact, the flow of water from above, through the extension 37 hydraulically connected to the interior of the column 8 by means of the hole 12F and the recess 12E, causes the contact between the moving element 11 and the resins 10 to be maintained. , pushing the first to the top surface of the last.

Thus, the detection of the height of the resins and, consequently, of the volume of the resins can always take place correctly through the position of the magnetic element 13.

By means of a water flow with a determined flow rate, which flows through the extension 37, the mobile element 11 is pushed, with the help of the spring 43, against the sample resins 10; In addition, the flow allows the compaction of the sample resins 10 to achieve an exact position of the magnetic element 13 with respect to its volume. It should be noted that the water used for calibration is softened previously.

Column 8 is slid down to a value equal to 5% of the height of compacted resin 10. The height of compacted resins before the displacement of column 8 is detected by a reader according to common procedures.

Therefore, the position of the magnetic element 13 is detected by the reed relay 18 of the sliding element 15, which moves when the element 15 slides along the outer wall of the cylindrical part 3 of the body 2 by means of the nut 19 ; The position of the magnetic element 13 is determined when the reed relay 18 is activated by the magnetic field produced by the element 13 itself and closes its own circuit (CONNECTION).

Now the point at which resin generation should begin is determined.

In fact, the displacement value of column 8, equal to 5% of the height of the compacted sample resins, substantially corresponds to a reduction in volume of the resins when they are in an exhausted state of about 80%; as mentioned, it happens in fact that, as they are used gradually during the operation of the washing machine, the resins become depleted and reduce their volume.

Column 8 returns to its initial position and becomes integral with body 2, welding or blocking plate 9 to plate 4 as is commonly known, and the movement of nut 19 is blocked by the use of paints or resins common.

During the operation of the washing machine, as the resins gradually deplete and reduce their volume, the mobile element 11 will additionally move down and also move the magnetic element 13 down, which causes the reed relay to close 18 (CONNECTION) when in line with him.

The closing of the reed relay 18 activates the resin regeneration phase through a cam A of an electromechanical programmer that allows the opening of a VR regeneration solenoid valve (see Figure 10).

Thus, the regeneration of resins only occurs when strictly required, avoiding waste of water and salt.

This regeneration phase, which consists practically in the supply of a water-salt solution to the softener, will obviously also affect the sample resins 10, since the water-salt solution is also flowed into the device 1 hydraulically connected to the softener through extension 37 of column 8.

In order to allow the resins 10 to mix better with the regeneration brine and make their regeneration easier, the coil 35 is activated at least once simultaneously with the opening of the VR regeneration solenoid valve by means of a cam of the electromechanical programmer predisposed for such function. The activation of the coil 35 produces a magnetic field within it, which attracts the ferromagnetic core N associated with the mobile element 11 inside the coil 35, thus causing a vacuum in the column 8 and a space between the mobile element 11 and the resins 10, which are then free to fluctuate and increase their contact with the regeneration solution. After a predetermined time, the coil 35 is deactivated and the mobile element 11 rests again on the resins 10 in a lower position with respect to the position it had before the activation of the coil 35, compacting them under the thrust of the spring 43, to allow the detection of the new

resin position 10.

Depending on the calibration value used, the resin never completely depletes, with the risk of using too much hard water for washing.

As stated, during the regeneration phase the resins come into contact with a concentrated saline solution; as a result, by virtue of the osmotic pressure exerted, the resins undergo an additional volume reduction with respect to the reduction caused by their normal depletion. This reduction in volume causes the mobile element 11 to move further along the magnetic element 13 associated with it. Thus, the reed relay 18 will be outside the magnetic field of the element 13 and will reach its open condition (DISCONNECT), stopping the regeneration phase. Thus, as can be seen, the duration of the regeneration phase or the amount of water used for that purpose can be a direct function of achieving the real restoration of resin efficiency.

Now, after a probable rest interval during which the resins can remain in contact with the saline solution, the programmer begins a first stage of resins washing, indicatively for a time of 5-7 seconds, to eliminate sodium ions in excess (Na +), activating the solenoid valve VC (see figure 10) for the water inlet of the distribution network, with a second programmer cam usually predisposed for such function.

In order to improve the washing of the resins 10, simultaneously with the opening of the VR regeneration solenoid valve, the coil 35 is activated at least once, attracting the ferromagnetic core N itself and, consequently, the moving element 11 associated with it. Thus, as already mentioned for the previous regeneration phase, there is a vacuum in column 8 and a space between the mobile element 11 and the resins 10, which are then free to fluctuate and increase their contact with the wash water. , to improve its salt elimination capacity and expand freely.

After a predetermined time, the coil 35 is deactivated and the mobile element 11 will again rest on the resins 10 in a higher position with respect to the position it had before the activation of the coil 35, compacting them under the thrust the spring 43, to allow the detection of the new position of the resins 10. The sudden displacement movement of the mobile element 11 will also produce a vacuum in the column 8, which sections the resins 10 and helps them to go upwards to facilitate their increase in volume.

In fact, after removal of excess sodium ions (Na +), said osmotic pressure decreases and, as a result, the sample resins will increase their volume; such an increase in the volume of the resins causes an upward movement of the mobile element 11 with the relevant magnetic element 13 to a position such that the reed relay 18 is activated and reaches its closing condition (CONNECTION).

The closing condition (CONNECTION) of the reed relay 18, through a third cam B (see Figure 11) of the electromechanical programmer, provides the activation of a second resin washing phase. Also, in this case, the coil 35 is activated and then deactivated for the purposes mentioned above.

During this second phase of resin washing, the resins will further increase their volume (due to a progressive osmotic pressure reduction), so that the movement of the mobile element 11 with the relevant magnetic element 13 will continue; The displacement of the element 13 is such that the reed relay 18 will be out of its magnetic field and will return to its open condition (DISCONNECT), stopping the resin washing cycle, since the resins have returned to their initial state.

Therefore, as can be seen, the duration of the resin washing phase or the amount of water used for this purpose can be a direct function of achieving real resin washing and avoid wasting water and power.

Since the exhaustion of the resins takes place gradually with each wash cycle, the programmer will not be able to activate the VR regeneration solenoid valve when the resins are only partially depleted, since, in this condition, the reed relay 18 is still in its open position (DISCONNECT) and will not access it.

In this case, the programmer will move on to the subsequent phases, namely the resting phase and the first phase of resin washing, which does not change the state of the resins (since there are no excess sodium ions (NA +) to be removed), and will leave the reed relay 18 in its open condition (DISCONNECT).

Now, a second phase of resin washing should begin; however, this will not take place, since the open condition (DISCONNECT) of the reed relay 18 does not access it as required.

As described above, it should be noted that the second phase of resin washing is carried out only when required and, therefore, with an additional saving of water and power.

It should be noted that if the reed relay 18 still maintains its own closing condition (CONNECTION) after starting a regeneration phase, this means that the resins have not regenerated, since the saline solution does not have enough salt.

In order to signal a fault of this type, it will be sufficient to use, for example, a warning light in series with the reed relay 18, which comes on at the end of the wash cycle, since the reed relay 18 is in its condition Closing (CONNECTION).

The warning light will also come on during the regeneration phase when the reed relay 18 is in its closed condition (CONNECTION), but will always be off at the end of the cycle when the reed relay 18 is in the open condition (DISCONNECT) after Regeneration has been performed.

Thus, with the device according to the present invention it is possible to obtain an additional advantageous characteristic, that is, the signaling of a lack of salt, without requiring the special detection devices currently used only for this specific purpose.

The various phases of operation of the device described above are shown schematically in Figure 7.

Phase 1 refers to the position of the magnetic element 13 with the sample resins 10 in its initial condition and with the reed relay 18 in the open condition (DISCONNECT).

Phase 2 refers to the position of the magnetic element 13 with the depletion of the sample resins 10; the reed relay 18 is in its closed condition (CONNECTION) because it is under the effect of the magnetic field of the magnetic element 13, which moves down due to the reduced volume of the resins 10. During this phase the valve is activated of VR regeneration and at least one coil activation / deactivation cycle 35.

Phase 3 refers to the position of the magnetic element 13 when the resins 10 are in contact during the regeneration phase with the saline solution with a high concentration of sodium chloride (NaCl); the reed relay 18 is in its open condition (DISCONNECTION) because it is no longer under the effect of the magnetic field of the magnetic element 13. This situation occurs because the magnetic field 13, after a further reduction in the volume of the resins caused by osmotic pressure, travels to an even smaller extent.

Phase 4 refers to the position of the magnetic element 13 during the first cycle of resin washing; the reed relay 18 is in its closed condition (CONNECTION) due to the displacement of the magnetic element 13 upwards after an increase in resin volume caused by a reduction in osmotic pressure. During this phase at least one cycle of activation / deactivation of the coil 35 is activated.

Phase 5 refers to the position of the magnetic element 13 at the end of the resin washing cycle; the reed relay 18 is in its open condition (DISCONNECT) after an additional displacement of the magnetic element 13 upwards due to an additional volume increase of the resins caused by a further reduction of the osmotic pressure.

Therefore, as can be seen, the invention, as described above, is susceptible to an advantageous application combined with an electromechanical programmer, since all the information generated by the device 1 related to the state of the sample resins 10 can be managed automatically at low costs using simple programmer cams.

Figure 3 schematically shows a vertical section of the front view of a second possible embodiment of a device for detecting the state of the resins of a water softener according to the present invention; Such device is indicated as a whole with 1A.

Device 1A differs from device 1 in Figure 1 by a second sliding element, indicated with 15A and provided with a relevant reed relay 18A, similar to those described and indicated previously with 15 and 18, respectively.

Both elements for detecting the position of the magnetic element 13 of the device 1A, either alone or together, allow a greater number of information to be generated with respect to the example of the device 1 of Figure 1; for this reason, the device 1A is more suitable to be associated with an electronic control device that will gather information and transmit it to the various components of the washing machine or to the user.

In practice, as described in more detail below, both detection elements produce a binary signal to be sent to a microprocessor.

The assembly procedures of the device 1 and the device 1A are similar, except that in the device 1A the sliding element 15A is also mounted according to the same assembly procedure for the sliding element 15 of the device shown in Figure 1.

After the calibration of the reed relay 18 of the sliding element 15, which is performed according to the same 5 procedures and ranges used for the device 1, the calibration of the reed relay 18A of the sliding element 15A will be performed according to the following procedure.

Column 8 slides down by a value equal to 10% of the height of the compacted resins.

10 The position of the magnetic element 13 is detected by the reed relay 18A of the sliding element 15A, which moves causing the element 15A to slide along the outer wall of the cylindrical part 3 of the body 2 by means of the nut 19 ; The position of the magnetic element 13 is determined when the reed relay 18A is activated by the magnetic field produced by the same magnetic element 13 and will close its own circuit (CONNECTION).

The 10% height offset value of compacted resins corresponds to a reduction in resin volume when immersed in a solution of water with a high concentration of sodium chloride (NaCl); as mentioned, in this condition, a part of sodium ions (Na +) of such solution enters the structure of the resin bead, while the remaining part of sodium ions (Na +), unable to enter the

The structure of the pearl produces an osmotic pressure on its external surface that compresses it and, consequently, reduces its volume.

The 1A device calibration is now complete.

25 Column 8 is brought back to its initial position and made integral with body 2, welding or blocking, as is known, plate 9 to plate 4, and nut 19 is blocked using common paints or resins.

During operation of the washing machine, as the resins gradually deplete and their volume decreases, the mobile element 11 consequently moves further downwards and, consequently, will also move the electrical element 13 downwards, which, when aligned with the reed relay 18, causes its closing condition (CONNECTION).

In such a situation, the reed relay 18A is still in its open position (DISCONNECT), since it is not involved by the magnetic element 13.

35 The closing (CONNECTION) of the reed relay 18 activates the resin regeneration phase with the opening of the regeneration solenoid valve; the opening of the regeneration solenoid valve is controlled by the electronic device that detects the closing condition (CONNECTION) of the reed relay 18. At the same time, at least one activation / deactivation cycle of the coil 35 is activated for them purposes described for device 1. With the

40 deactivation of the coil 35, the mobile element 11 once again rests on the resins 10 in a lower position with respect to the position it had before the activation of the coil 35, and compacts them under the thrust of the spring 43, to allow the new position of the resins 10 to be detected.

The downward movement of the magnetic element 13, due to an additional volume reduction of the 45 resins in contact with the regeneration salt-water solution, involves the reed relay 18A and causes its closure (CONNECTION).

Now, the reed relay 18 is still in its closed condition (CONNECTION), since the reed relays 18 and 18A are properly arranged to be both involved by the magnetic field of the element 13.

50 The electronic device that detects the closing condition (CONNECTION) of both reed 18 and 18A relays activates the closing of the regeneration solenoid valve.

After closing the regeneration solenoid valve, the electronic device will activate a rest interval 55 in the cycle of the washing machine.

After a predetermined time, with the reed 18 and 18A relays in the closed position (CONNECTION), the electronic device activates the water inlet solenoid valve for a first phase of resin washing, indicatively for a time of 5-7 seconds , to reduce sodium ions in excess (Na +). Simultaneously

60 with the water inlet valve at least one cycle of activation / deactivation of the coil 35 is activated through the electronic programmer for the purposes already described for the device 1.

After deactivation of the coil 35, the mobile element 11 once again rests on the resins 10 in a higher position with respect to the position before the activation of the coil 35, compacting them under the thrust of the spring 43, to allow the detection of the new position of the resins 10.

In fact, the elimination of sodium ions (Na +) in excess causes the osmotic pressure to decrease and increase the volume of the resins; such an increase in volume of the resins causes an upward movement of the mobile element 11 with the relevant magnetic element 13.

With the upward displacement of the element 13, its magnetic field no longer affects the reed relay 18A, which, therefore, assumes the open condition (DISCONNECT), while the reed relay 18 remains in the closed position (CONNECTION), being still involved by the magnetic field of the magnetic element 13.

The electronic control device that detects such conditions of the reed relays activates a second phase of resin washing.

Also, during this second phase of resin washing at least one cycle of activation / deactivation of the coil 35 is activated to satisfy the same purposes and the same procedures related to the first phase of rinsing.

During this second washing phase, the resins continue to increase their volume with the consequent displacement of the moving element 11 together with the relevant magnetic element 13; this displacement is such that the reed relay 18 will be outside the magnetic field of the magnetic element 13 and will return to its open condition (DISCONNECT), stopping the resin wash cycle, which now returns to its initial state.

Therefore, as can be seen, both reed 18 and 18A relays practically form a 2-bit digital signal, suitable for interacting with binary logic, such as one that monitors the operation of a microprocessor normally used in the electronic control device of a wash machine.

Therefore, also in this case, the washing of resins is carried out only for a required time, to avoid a waste of water and power.

In addition, whenever there is a gradual depletion of the resins in each wash cycle, the electronic control device will not activate the regeneration solenoid valve when the resins are only partially depleted; in this condition, in fact, the reed relay 18 is still in its open position (DISCONNECT).

In this case, the electronic control device will skip all previously described phases (regeneration, rest interval, first and second resin washing steps).

If regeneration is activated and, after closing the regeneration solenoid valve, the reed relay 18 is in the open condition (DISCONNECT), while the reed relay 18A is still in the closed condition (CONNECTION), this means that there is Too much salt in device 1, that is, the water-salt solution in contact with the resins is saturated with sodium chloride (NaCl).

The electronic control device detects this situation and activates a signal, such as a warning line that signals this defective condition.

A subsequent opening (DISCONNECT) also of the reed relay 18A indicates a failed condition of the device, such as lack of sample resins.

In this case, the electronic control device that detects such a situation can inform the user about the failed condition by means of a warning light or similar device and restore the regeneration of the softener resins in each wash cycle, excluding the device 1A .

If, at the end of the regeneration cycle, the reed relay 18 is still in the closed condition (CONNECTION) and the reed relay 18A is in the open condition (DISCONNECT), this means that the resins have not been regenerated because the solution Saline used does not contain enough salt; The electronic control device that detects such a condition can inform the user through a luminescent and / or acoustic signal that it needs salt to be added to the relevant tank.

If after adding salt, the reed relay 18A is still in the open condition (DISCONNECT), the electronic control device will signal a malfunction of the regeneration valve or a jamming of the detection device mechanism.

Before signaling such a failure, the control device will activate and deactivate the coil 35 to eliminate a possible blockage of the mobile element 11, which may be due, for example, to broken resin beads. If the fault cannot be eliminated, then the electronic control device will indicate it. Therefore, in this case, it is necessary to call the technical service.

The various phases of operation of the device described above are represented in a manner

schematic in figure 8.

Phase 1 refers to the position of the magnetic element 13 with the resins 10 in their initial condition and with the reed relays 18 and 18A in their open condition (DISCONNECTION).

Phase 2 refers to the position of the magnetic element 13 after the exhaustion of the resins 10; the reed relay 18 is in the closed condition (CONNECTION) because it is under the effect of the magnetic field of the magnetic element 13, which moves down due to a reduction in the volume of the resins 10. During this phase, activates the solenoid valve for the regeneration of the resins, as well as at least one cycle of activation / deactivation of the coil 35. On the contrary, the reed relay 18A is in the open condition (DISCONNECT), since it is not involved still by the magnetic field of element 13.

Phase 3 refers to the position of the magnetic element 13 when the regeneration solenoid valve is deactivated; the reed relays 18 and 18A are both in their closed condition (CONNECTION) because they are both subordinated by the magnetic field of element 13. Therefore, the electronic control device, which detects the closed condition (CONNECTION) of the reed relays 18 and 18A, provides deactivation of the regeneration solenoid valve.

If the reed relay 8A, after a predetermined time, is still in the open condition (DISCONNECT) instead of the expected closed condition (CONNECTION), the electronic control device provides information to the user by means of luminescent or acoustic signals that salt needs to be added.

If, after adding salt, the reed relay 18A is still in the open condition (DISCONNECT), the electronic control device proceeds to signal a malfunction of the regeneration valve or a jamming of the detection device mechanism.

Phase 4 refers to the position of the magnetic element 13 when, during the regeneration phase, the resins 10 come into contact with a saline solution with a high concentration of sodium chloride (NaCl), which determines an additional volume reduction of the resins due to osmotic pressure. Reed relay 18 is in the open condition (DISCONNECT) and reed relay 18A in the closed condition (CONNECTION); these conditions are conferred by the displacement of the magnetic element 13 after a reduction in the volume of the resins 10. The electronic control device, which detects at this point the failed opening condition (DISCONNECTION) of the reed relay 18 and the closed condition ( CONNECTION) of the reed relay 18A, proceeds to activate a signal, such as a warning light or similar device, to indicate the presence of too much salt.

Phase 5 refers to the position of the magnetic element 13 when the sample resins 10 are missing due to a device failure; in this case, the reed relays 18 and 18A are in the open condition (DISCONNECT) and the electronic control device, which detects such conditions, proceeds to inform the user of such a fault by means of a warning light or device similar and to restore the regeneration of the softener resins in each wash cycle, excluding the device 1A as long as the missing sample resins 10 are not restored again.

Phases 6 and 7, although detected by the electronic control device, are not used in the previously described embodiment of the invention.

Phase 8 refers to the position of the magnetic element 13 when the resin washing cycle begins; the reed relay 18 is in the closed condition (CONNECTION) due to the upward displacement of the magnetic element 13, after an increase in the volume of the resins, while the reed relay 18A is in the open condition (DISCONNECT). During this phase at least one cycle of activation / deactivation of the coil 35 is activated.

Phase 9 refers to the position of the magnetic element 13 at the end of the resin washing cycle; the reed relays 18 and 18A are both in the open position (DISCONNECT) due to the upward movement of the magnetic element 13 after a further increase in the volume of the resins 10; The electronic device, which detects such conditions of the reed 18 and 18A relays, proceeds to deactivate the water inlet valve used for the washing of resins.

From the above description it is obvious that more information can be obtained with the device 1A; The detection of such data and its use can be advantageously managed by an electronic control device, such as a microprocessor, as previously mentioned.

The electronic control device, not represented or described as being a common type, detects and processes the data derived from the conditions of the reed 18 and 18A relays, finally storing them, and manages all the operations of the washing machine.

Figure 4 schematically shows a partial perspective view of a device for detecting the state of the resins of a water softener according to the present invention, referring to the second possible embodiment of the

device according to the invention.

Figure 5 schematically represents a cross section of a device for detecting the state of the resins of a water softener according to the present invention, referring to the first configuration of the device for detecting the state of the resins, as described with reference to the figure 1, respectively; However, this figure may also refer to the second configuration of the device, that is, that of Figure 3, bearing in mind that, in this case, two sliding elements must be provided.

Figure 6 schematically illustrates a sectional view of the position and hydraulic connection of a device 1 according to the present invention to a softener D.

Reference 45 indicates an insertion hole of the extension 37 of the device 1 in the body of the softener D, for the hydraulic connection of the first to the last.

The hole 45 is hydraulically connected to a recess 46 inside the resin container R of the softener D. The recess 46 has grooves 46A in its bottom wall for the hydraulic connection of the recess to the inner side of the resin container. The grooves 46A are sized to allow water to flow through, but not the resins R.

It should be noted that the bottom wall of the recess 46 is located in the softener D at a height above the lower level of the resins R contained in the softener device.

Such height is predetermined so that the water from the softener D entering the device 1 through the grooves 46A has already been partially softened by the resins R of the softener D. Such a measure is dictated by the requirement to prevent the resins 10 of the device 1 become depleted when the softener resins D are not yet completely depleted.

In fact, if the water from the distribution network directly reaches the device 1 in the form provided and provided that the amount of resins 10 contained therein is less than the amount of resins contained in the softener D, the device 1 can operate under conditions of its own resins different from those of softener resins D.

The position of the supply point of the device 1 in the softener D is also determined to cause it to perform a regeneration when the resins R of the softener D have not yet reached full exhaustion. In fact, water from the distribution network flows in softener D from the bottom up; this causes the R resins to become depleted starting from the bottom, that is, the lower ones will be exhausted first and then all the others will gradually rise. The hydraulic location of the device 1 above the lower level of the resins R of the softener D is thus provided so that the latter works for regeneration purposes when the resins R of the softener D, above the supply point of the device 1, do not They have sold out yet. Thus, complete exhaustion of all resins R of the softener R will not occur before regeneration.

Reference 24 indicates a conduit to drain the water flowing in the device 1 and to allow it to enter the water supply conduit to the washing machine.

The conduit 24A has a suitable way to be accommodated within the column 8 of the device 1; such coupling is made integral by common means; The coupling between the conduit 21A and the column 8 is hydraulically sealed by means of at least one seal, such as a sealing ring. The extension 38 of the device 1 is connected directly through a connector 47 to the salt container for the regeneration of the resins 10 contained in the device 1.

The characteristics of the present invention, as well as the relevant advantages thereof, are obvious from the above description and the appended claims.

As can be seen from the above description, the system according to the invention employs a simple device of small size, easy to manufacture at low cost. In particular, since the coil 35 is capable of displacing the mobile element 11 and providing more space for the resins 10 to fluctuate during the regeneration and / or washing process, the operation of the system to detect the state of the resins is improved.

In addition, according to one of the above embodiments, the device provides efficient automatic control of the regeneration operations, including a washing of resins after regeneration, also when a standard electromechanical programmer is used. As mentioned, the regeneration and / or washing of resins according to the invention can be directly controlled to avoid wasting resources.

In addition, the device has a high reliability of operation, since the depletion of the resins is detected by direct surveillance, and without keeping the hardness of the water under control, from which only the degree of depletion of the resins can be indirectly deduced. .

Also, replacing a possibly defective detection device is very simple, since it is mounted outside the softener D; This obviously improves the technical characteristics of the device according to the invention.

The detectors of the position of the magnetic element 13 are calibrated, for example, to allow regeneration when the exhaustion of the resins reaches about 80%, which corresponds to a well-determined position of the magnetic element 13; thus, the regeneration of the resins R only takes place when strictly required, avoiding a waste of water and salt; In addition, doing so, R resins never reach full exhaustion with the risk of using water that is too hard for washing.

With such a calibration and detection procedure it is also possible to determine if the salt in the relevant tank is excessive or missing.

Therefore, it is possible to have an optical or acoustic signaling of a lack of salt without using a floating system, as is typical for the present state of the art, which seems to be sufficiently reliable to turn off a warning light after the user has salt added to the relevant container, but that is often very inaccurate to signal a lack of salt.

In addition, the washing of the resins also takes place only when it is really required, even if a standard electromechanical programmer is used, saving water and power.

The working position, with water supplied from top to bottom, improves the operating conditions of the device according to the invention, avoiding an incorrect position of the mobile element 11, which could cause problems of detecting the position of the magnetic element 13 with respect to the height of resins 10.

The possibility of having the mobile element 11 performing an extra movement through the coil 35 allows an improvement in the regeneration of the sample resins 10 and facilitates the mixing of the brine with the resins, as well as an improvement in the removal of excess of salt during rinsing, and reduces probable blockages of the mobile element 11 due to rests of resin beads.

It is obvious that many changes in the system, the device and the procedures covered by the present invention are possible for the person skilled in the art without departing from the novel spirit of the innovative idea.

According to a possible implementation, instead of a reed relay, a Hall effect sensor or an electric microswitch can be used.

The detection device can be incorporated totally or partially in the softening device. According to a further embodiment, the detection device could be materialized without the coil 35 for temporary activation of the mobile element 11, as shown in Figure 11. Figure 11 schematically represents a vertical section of a detection device comprising such implementation and which is indicated as a whole with the number 1B. In the following, only the components changed with respect to the device 1 will be described, while the remaining components similar to the other embodiments are identified with the same reference numbers.

The number 36 'indicates a closing cover of the upper end of the hollow cylindrical part 3 of the body 2. With 12' a rod is indicated which has at one end the cylindrical extension 12A with a diameter greater than the rod itself, suitable for insertion inside the base 11A of the mobile element 11 and containing the magnetic element

13. The rod 12 ’has a vertical cylindrical recess 12′E inside which is suitable for hydraulic connection of the sample resins 10 with the conduits 39 and 40 by means of the grooves 14’.

With this execution, the vertical movement of the mobile element 11 will take place only as a function of the volume change of the sample resins 10.

To aid the mobile element 11 in its downward movement and to overcome the small frictions that may occur between the mobile element 11 and the inner wall of the column 8, a spring can be inserted between the mobile element 11 and the closing cover 36 ' of the upper end of the hollow cylindrical part 3 of the body 2.

Figure 11 represents such an embodiment for a device with a single sliding element 15, but the same embodiment can also be applied to a device having two sliding elements 15 and 15A.

A further implementation may consist of materializing a sealing gasket between the mobile element 11 and the inner wall of the column 8, preventing a leakage of resin particles capable of clogging the movement of the mobile element; A seal can be obtained through a lip seal at the edge of the movable element 11.

Obviously, various ways of practicing the invention are possible for the person skilled in the art, both for machines with an electronic control system and for machines with an electromechanical control system.

Claims (38)

1. System for reducing the hardness of water as required for the operation of an appliance, in particular a domestic washing machine, using resins (R, 10) that reduce its own softening capacity depending on the amount of treated water, providing the system with means to obtain:

-

softening phases, during which the water to be softened and required by said use apparatus is brought into contact with said resins (R; 10), and

-

stages of restoring the softening capacity of said resins (R, 10), during which a flow of water is supplied to said resins (R, 10), said flow being used in particular or in association with a regenerating agent , in order to regenerate said resins (R, 10) or to wash the regenerated resins (R, 10),

said system further comprising control means (1; 1A; 1B) capable of controlling, when required, the beginning of said reset phases, said control means comprising a detection device (1; 1A; 1B) that functions to

-

detecting, after having started at least one of said restoration phases, volume changes of a quantity of sample resins (R, 10), and

-

produce, when a change in the volume of said sample resins (10) reaches at least a first predetermined threshold value, an interruption signal of said restoration phase or of the supply of said water flow to said resins (R, 10) .

so that the duration of said restoration phases and / or the amount of water used during them are a function of the actual restoration achieved of the softening capacity of said resins (R, 10), said detection device comprising (1; 1A ; 1B) a mobile element (11) capable of adopting at least a first operating position, in which said mobile element (11) defines a space for containing said resins (R, 10), characterized because said detection device (1; 1A; 1B) further comprises drive means (35, N) for moving said mobile element (11) to at least a respective second operating position, in which the volume of said containment space it is greater than in said first position, to favor the mixing of said sample resins (10) with the water flow used during said phases of restoring the softening capacity of said sample resins (10).

2.

 System according to claim 1, characterized in that said actuating means (35, N) comprise an electromagnetic coil (35) and a ferromagnetic core (N), said ferromagnetic core (N) being inserted into said coil (35), so that slide freely.

3.

 System according to claim 1, characterized in that said detection device (1: 1A; 1B) also functions to detect, after the execution of at least one of said softening phases, changes in the volume of said resins (R, 10) and producing, when a change in the volume of said sample resins (10) reaches at least a second predetermined threshold value, a signal initiating said restoration phases or entering said water flow into said resins (R, 10) and an activation and / or deactivation signal of said drive means (35).

Four.

 System according to claim 1, characterized in that said detection device (1; 1A: 1B) comprises:

-

a magnetic element (13), in particular a permanent magnet, capable of changing its position depending on the change in the volume of said sample resins (10);

-

detection means (18, 18A) to detect the position of said magnetic element (13).

5.

 System according to at least one of the preceding claims, characterized in that said control means (1; 1A; 1B) comprise an electromechanical programmer and / or an electronic control device, not for managing the signals produced by said detection device (1; 1A; 1B), but in particular for the control of said restoration phases.

6.

 System according to claim 4, characterized in that said detection device (1; 1A; 1B) comprises a body (2) containing said sample resins (10), said magnetic element (13) being able to change its own position as a function of changing the volume of said sample resins (10) and said body (2) being hydraulically connected to a container (D) of softening resins (R), so that the water used for

said softening phases and the water used for said restoring phases are contacted with said sample resins (10) and with said softening resins (R).

7.

 System according to claim 4, characterized in that adjustment means (15, 15A) of the position of said detection means (18, 18A) with respect to the body (2) of said detection device (1; 1A; 1B) are provided. ), said adjustment means (15, 15A) being provided, in particular, for the initial calibration of said detection device (1; 1A; 1B).

8.

 System according to at least one of the preceding claims, characterized in that in said body (2), in particular in the middle thereof, a tubular element (8) is present, such as a cylindrical hollow column, said sample resins being contained ( 10) in said tubular element (8).

9.

 System according to the preceding claim, characterized in that said magnetic element (13) is associated with said mobile element (11) and the latter is placed in said tubular element (8), in particular in contact with said sample resins (10), and It is apt to change its position after a change in the volume of the latter.

10.

 System according to claim 4, characterized in that said detection means (18; 18A) comprise reed relay type sensors (18; 18A) and / or Hall effect type sensors and / or at least one electric microswitch.

eleven.

 System according to claim 7, characterized in that said adjustment means (15; 15A) comprise at least one sliding element (15; 15A), to which said detection means (18; 18A) are associated, and a threaded pin (17) associated with said sliding element (15; 15A), a nut (19) and an elastic element, such as a spring (20).

12.

 System according to at least one of the preceding claims, characterized in that the lower part of said tubular element (18) has grooves (114) for the hydraulic connection with said container (D) of said softening resins (R).

13.

 System according to at least one of the preceding claims, characterized in that the upper part of said body (2) has a hollow cylindrical part (3), said cylindrical part (3) having three sections (3A, 3B, 3C) with an internal diameter different from each other, in particular one of said sections (3B) having a smaller diameter with respect to the other two (3A, 3C).

14.

 System according to at least one of the preceding claims, characterized in that the upper part of said body (2) has a first (37) and second (38) projections symmetrically opposed to each other and perpendicular to one of said sections (3C) of said body (3), said first (37) and second (38) projections having a conduit (39; 40) suitable for hydraulically connecting the exterior with the interior of said body (3).

fifteen.

 System according to the preceding claim, characterized in that said conduit (39) of said first projection (37) is suitable for the hydraulic connection of the resins (10) contained in the device (1; 1A; 1B) to a resin container (R ) of a water softener device (D).

16.

 System according to claim 14, characterized in that said conduit (40) of said second projection (38) is suitable for the hydraulic connection of the sample resins (10) contained in the device (1; 1A; 1B) to a salt container of a water softening device (D), said conduit (40) of said second projection (38) having interception means (42) of the water coming from said conduit (39) of said first projection (37), comprising in particular said interception means (42) a check valve (42).

17.

 System according to at least one of the preceding claims, characterized in that said mobile element (11) has a substantially cylindrical and hollow base (11A) closed at one end, said end in particular having recesses (14) for hydraulic connection to said sample resins (10).

18.

 System according to at least one of the preceding claims, characterized in that said mobile element (11) is associated with a rod (12), said rod (12) having a cylindrical extension (12A) at one end, the diameter of which is greater than that of the rod itself, suitable for inserting into the inner part of said base (11A) of said mobile element (11).

19.

 System according to claim 18, characterized in that said rod (12) has a first (12B) and second (12C) parts, said first (12B) and second (12C) being divided between them by a plate (12D), presenting in particular said first part (12B) a vertical cylindrical recess (12E) between said plate (12D) and said end (12A), said cylindrical recess (12E) having a hole (12F) perpendicular to it for its external hydraulic connection.

twenty.

 System according to at least one of the preceding claims, characterized in that said extension (12A) has a round recess suitable for containing said magnetic element (13).

twenty-one.

 System according to at least one of the preceding claims, characterized in that said second part (12C) of said rod (12) has inside said ferromagnetic core (N), this being inserted in particular within said coil (35).

22

 System according to at least one of the preceding claims, characterized in that said upper part of said body (2) is closed by a cover (36), said cover (36) having a hole in the center (41) to pass through it said second part (12C) of said rod (12).

2. 3.

 System according to at least one of the preceding claims, characterized in that said coil (35) is fixed to said cover (36) to close the upper end of said body (2).

24.

 System according to claim 19, characterized in that said plate (12D) defines the entrance of said mobile element (11) into said tubular element (8).

25.

 System according to at least one of the preceding claims, characterized in that an activated signaling means are provided in reference to detections carried out by said detection device (1; 1A; 1B), in particular to indicate the absence in the system of a regeneration agent of said resins (R, 10) and / or a system failure.

26.

 System according to at least one of the preceding claims, characterized in that the hydraulic connection of said detection device (1; 1A; 1B) with said container (D) of said softening resins (R) is substantially located at the top of the latter .

27.

 System according to at least one of the preceding claims, characterized in that said detection device (1; 1A; 1B) is connected hydraulically by branch with respect to said container (D) of said softening resins (R).

28.

 System according to at least one of the preceding claims, characterized in that said detection device (1; 1A; 1B) also functions to detect the degree of regeneration of said resins (R, 10) depending on the changes in volume of the latter.

29.

 Control procedure of a system to reduce the hardness of water as required for the operation of a use apparatus, in particular a domestic washing machine, using resins (R, 10), which reduce the softening capacity itself as a function of the amount of water treated, providing said system operation at least:

-

softening phases, during which the water that must be softened and required by said use apparatus is contacted with said resins (R, 10), and

-

regeneration phases of the softening capacity of said resins (R, 10), during which an aqueous solution containing a regenerating agent is supplied to said resins (R, 10),

characterized in that, in order to control said regeneration phases, said process provides:

-

a direct detection, during said regeneration phases, of changes in the volume of a quantity of sample resins (10)

-

an interruption of said regeneration phases or of said aqueous solution supply to said resins (R, 10) when the volume changes detected of said sample resins (10) reach at least a certain value, which is indicative of obtaining an efficient regeneration of the softening capacity of said resins (R, 10), said interruption being determined by the detection of a certain reduction in the volume of said resins (10) with respect to the volume they had at the beginning of the regeneration phase,

-

at least one step of increasing the volume of the space in which said sample resins (10) are contained, in order to favor the mixing of said sample resins (10) with the water flow used for regeneration, said said at least one stage of volume increase before said detection.

30

 Method according to claim 29, characterized in that it comprises at least one phase of washing the resins, during which a flow of water is supplied to said resins (R, 10) as required to perform the washing of the resins (R, 10 ) previously regenerated.

31.

 Method according to claim 29, characterized in that it provides the direct detection of volume changes of said sample resins (10) also after the execution of at least one of said softening phases and the beginning of one of said regeneration phases when the change in volume detected of said resins (R, 10) reaches at least a certain value, which is indicative of the depletion of the capacity of

softening of said resins (R, 10).

32

 Method according to one or more of the preceding claims 29 to 31, characterized in that signal means are activated, when the change in volume of said sample resins (10) does not reach a value

5 after starting a regeneration phase, to indicate a failure of said softening system and / or the need to add a regenerating agent in a relevant container belonging to said system. 33. Method according to one or more of the preceding claims 29 to 31, characterized in that a The regeneration phase after the detection of a decrease in the reduced volume of said sample resins (10) with respect to a first predetermined threshold, which is indicative of the depletion produced in the resins (10, R). 34. Method according to the preceding claim, characterized in that the interruption of a regeneration phase 15 takes place after the detection of an additional volume reduction of said sample resins (10), up to a second predetermined threshold, which is indicative of the regeneration produced in the resins (10, R). 35. Method according to the preceding claim, characterized in that an excess of said agent is deduced from regeneration if, after the interruption of the regeneration phase, an additional volume reduction of said sample resins (10) with respect to said second predetermined threshold is detected. 36. Method according to claim 31 or 32, characterized in that the interruption of a resin washing phase occurs after the detection of an increase in the volume of said resins (10, R) with respect to said first predetermined threshold. 37. Method according to the preceding claim, characterized in that said sample resins (10) are subjected, before use, to a preliminary depletion-regeneration-washing cycle. 38. Household washing machine, in particular dishwashing machine, comprising the system for reducing the hardness of water according to one or more of the preceding claims 1 to 28.