GB2044295A

GB2044295A - Apparatus for Electrolytically Purifying or Softening Liquid

Info

Publication number: GB2044295A
Application number: GB7941666A
Authority: GB
Original assignee: PACE I
Current assignee: PACE I
Priority date: 1978-12-06
Filing date: 1979-12-03
Publication date: 1980-10-15
Also published as: GB2044295B; SE7910023L; CA1132483A; DE2948462A1

Abstract

In apparatus comprising a liquid flow sensor e.g. 103 controlling the frequency of electrical pulses applied from a pulse generator across a first electrode formed by an elongate reservoir e.g. 110 for the liquid and electrode probe e.g. 106 extending into the liquid through a wall of the reservoir, the reservoir is enclosed in a housing 101 to one wall of which is secured a second housing 104 containing the generator access to the probe e.g. for cleaning is effected by disengaging the housings. This arrangement has the advantages of being compact, easy to install and requires little maintenance. In an embodiment the reservoir is sealed by blocks 111, 114 secured to tube 110 by probe 106. Piston 117 is mounted coaxially of probe 106 in a blind bore of block 111. The position of the piston varies with liquid flow and in turn varies the pulse frequency. <IMAGE>

Description

SPECIFICATION Apparatus for Purifying or Softening Liquid The present invention relates to apparatus for purifying or softening liquid such as water, and particularly for neutralising the encrusting effects of calcium carbonates whilst effecting a progressive de-scaling of the water.

A number of such electrical apparatus are known. Such apparatus are adapted to apply an automatically adjustable and weak predetermined pulsed current to the terminals of electrodes housed in a tank, the control of these pulses being achieved by means of a treated liquid flow sensor linked to an electronic transmitter.

Known apparatus, for the most part, are very safe but nevertheless require elaborate installation as well as constant surveillance of the state of the negative electrode since the latter becomes encrusted with scale thus progressively diminishing its effectiveness. For these reasons the known apparatus present a number of problems. The flow sensors of certain known apparatus are provided with a float chamber, and it is necessary when each apparatus is installed to ensure that it is mounted vertically in order to avoid possible mal-functioning of that float and consequently of the apparatus. Other known apparatus, for reasons of user safety, must be disconnected from their power supply when the negative electrode is removed for cleaning.

Moreover the known-apparatus for the most part have their electronic pulse transmitters located at a distance and separate from the main body containing the water circulation tank. This arrangement takes up a considerable amount of space that is not always easy to find in a user's premises.

Consequently, given the above problems in known such apparatus there is a need for a compact liquid purifying or softening apparatus, easy to install, requiring little maintenance and safe to operate.

According to the invention, there is provided apparatus for purifying or softening a liquid, comprising an elongate reservoir closed at both ends and serving as an electrode, a second electrode formed by a probe extend through one end wall of the reservoir into the latter and being secured to said end wall in a liquid tight and insulating manner, a pulse generator operable to apply a pulsed current to said electrodes, a sensor located adjacent an outlet of the reservoir for sensing the flow of treated liquid and controlling said generator in dependence thereon; and wherein said reservoir is enclosed in an elongate first housing to one end wall of which is secured a bottom wall of a second housing containing said generator, the arrangement being such that access to said probe is effected only by disengaging said first and second housings.

The de-scaling apparatus, according to a first embodiment of the invention is made up of two housings assembled together in one unified assembly, but which can be separated one from the other as required for maintenance, the smaller housing being a box adapted to contain the pulse generator which, at the command of the flow sensor, apply peak electrical pulses to the positive and negative electrodes.The other housing of elongate shape is adapted to contain the reservoir for the circulation and treatment of liquid such as water and is in the form of a cylindrical reservoir closed at both ends, forming one of the electrodes, at least one of these ends being traversed by the other electrode or probe, which has its electrical supply base, fixed by a strap in a watertight and insulating manner on this end of the reservoir and enclosed in a cavity which is provided in the bottom of the box, the latter being fixed by screw-threaded gudgeons onto the corresponding outside wall of the elongate casing, the fitting together being such that, the removal of the electrode or probe immersed in the reservoir is only possible if the said box has been separated in the first place from the said elongate casing.

In addition, the apparatus is provided with a safety cut-out of the supply current to the electrodes, which is made of plugs corresponding to the electrical connections between the pulse generator and the said electrodes, the plugs having the female socket fixed in an insulating manner through the bottom of the said box, whilst the corresponding male pin is fixed in an insulating manner in the wall of the elongate housing opposite and onto which the bottom is placed so that when the casing is dismantled with a view to removing the immersed-electrode for example, the disconnection of the said electrode is compulsorily achieved without risk to the user even if the latter has omitted to disconnect the principal supply from the pulse generator transformer.

Moreover, the cylindrical circulation reservoir for water to be treated and enclosed in the elongate housing forming one of the two electrodes is formed of such dimensions that its length is approximately equal to about four times its internal diameter, and comprises laterally, in the area of each of its two extremities, a water inlet or out-let orifice integrally jointly linked in a water-tight manner to a pipe union of the pipe system passing through the corresponding lateral wall of the housing.Moreover the reservoir is provided internally with a continuous chicane made up of a helical strip or worm of insulating material which is indeformable by heat, one end of which corresponds to one of the lateral orifices and the other end to the other lateral orifice each of the orifices being able to be used without distinction for the in-take or evacuation of water, the said helical strip being longitudinally traversed at its centre by the said probe and conceived with a gap between stepping designed to provide a race of water which in cross-section is approximately equal but not less than that of the pipe system through which the water to be treated enters, considerably increasing the course of circulation and treatment of the latter.

On the other hand, with a view to cutting down the maintenance and cleaning sequences of the probe, the pulse generator enclosed in the said box is conceived to generate polarised pulses, split at the secondary of a transformer by a triac operated in phase, and comprises a polarity reversal device intended to cause the automatic cleaning of the said probe, the device comprising a threshold sensor adapted to switch when the said probe is loaded with a deposit of scale and which, as a result, the current diminishes the switching reversing the direction of the pulses, so that the probe receiving positive pulses is progressively freed of the deposit of nonencrusting scale until the current increases and causes a new reverse switching of the threshold sensor, which commands negative pulses to be released to the probe and, then, the return to normal functioning of the apparatus.In addition to avoid the influx of non-encrusting scale into the treated water removal pipe system following the automatic cleaning of the probe, a filter for trapping and eliminating the scale which has a simple construction and is easy to replace, is provided in the pipe system below the apparatus.

As has been mentioned earlier and according to the invention, the apparatus, in its first embodiment, comprises a water flow sensor mounted on the treated water out-let of the reservoir. The sensor comprises a body of nonmagnetic material into which a passage for water circulation is made linking an in-take or out-let orifice of the reservoir to an evacuation orifice, on to which is connected the treated water out-let pipe system of the apparatus. The body of te sensor, in the form of T, comprises a straight bore cylinder situated in the extension of the inlet or outlet orifice of the reservoir, on which is provided a slidable block in magnetic material which is mounted in a slidable manner with creeping adjustment.The block closes the water evacuation orifice when in a position of rest and is adapted to move under the pressure of the water current into an electrical winding surrounding the end of the straight bore opposite the water inlet orifice, whilst progressively opening the water evacuation orifice following the through-flow commanded, the winding being linked by electrical conductors to the pulse generator. The slidable block is made up of a blind straight bore sleeve, in which is housed a spring adapted to recall the slidable block into position to close the water evacuation orifice when through-flow is not commanded, the spring at one end pressing against a screw-threaded cap which closes in a watertight manner the bored out end of the body of the sensor on this side of the winding, and its other end resting on the inside of the bottom wall of the slidable block.Several escape holes are provided in the lateral wall of the latter.

Moreover, in the part surrounded by the winding, the body of the sensor has a greater external diameter than that in which the water passage is cut, and the bore of this part is also of greater diameter than that of the bore where the slidable block moves, the latter being provided with a flange adapted to come into abutment with the shoulder between the two bores and mounted in creeping adjustment in the bore of the said part onto which the winding is fixed.

It must be noted that, in certain cases of use, the flow sensor having on the one hand a body of non-magnetic material and on the other a slidable block of magnetic material, presents certain difficulties because of the different behaviour of these materials in the course of time in water and in heat. Consequently the inventor has conceived another sensor comprising in its assembly material reacting in the same manner to water and heat.

Such a flow sensor comprises, according to the invention and as in the former embodiment, a principal body in which a treated water circulation passage is made linking an inlet or outlet orifice of the reservoir to the evacuation orifice, a slidable block adapted to move in the passage under the pressure of the water current and restrained by a return spring in order to regain its rest position when the current ceases.The principal body of the sensor, preferably of plastics material of the PVC type, is in the form of a right prism of polygonal section or of a cylinder provided with a central longitudinal bore forming the water circulation passage and comprising on each side of this bore, two housings situated at the same level between the intake orifice and the evacuation orifice of the water, the housings being adapted to contain, in one a light source and in the other a photoelectric cell, situated so as to be struck by the light beam from the source crossing perpendicularly the said bore, the slidable block being designed in such a way that in a rest position it cuts, by forming a screen, the light beam, at the very time when it moves towards the water outlet orifice, it progressively allows the said light beam to pass, which hits the photoelectric cell linked to the pulse generator of the de-scaling apparatus.

In a more specific manner and according to the invention, the slidable block is made up of a blind bore sleeve, the open end of which is situated beside the intake orifice, at the time its closed end compresses the return spring and the lateral wall of which is provided with several water passage orifices cut near to the closed end, the position of these orifices as well as the length of the slidable block is envisaged so that when the block moves towards the outlet orifice, it breaks the said light beam at the time when the water passage orifices are in communication with the removal orifice. In addition the water passage orifices of the slidable block are envisaged distributed around the lateral wall of the latter at the same level, their diameters being identical and chosen so that the addition of their sections is at least equivalent to the section of the water evacuation orifice.

Moreover, the water circulation passage made up by the central bore, in which slides the slidable block is bored out in the part corresponding to the water evacuation orifice in order to form an outlet chamber of greater cross-section, making space between its internal wall and the external wall of the slidable block when it (the slidable block) penetrates there under the influence of the water current, for a rim of cross-section at least equal to that of each of the intake and evacuation orifices and of the central bore proper, the latter being provided with identical cross-sections. On the other hand the outlet chamber is provided, beyond the outlet orifice with a closing cap mounted in a watertight manner and onto which bears one end of the return spring, the other end of the spring bearing on the closed end of the slidable block facing the cap.

A transverse light conduit is provided to link the light source and photoelectric cell housings respectively, and is situated so that it is obscured by the lateral wall of the slidable block when it is in a rest position. In addition, the light conduit, cut so as to be perpendicular to the bore forming the water circulation passage and to pass through the centre of it, (i.e. either the bore or the passage) is divided into two lateral conduits by the said bore, the end of each opening into the latter being envisaged provided with an identical or slightly greater diameter than that of each of the water passage orifices of the slidable block, at the same time their opposite ends are bored out to house respectively the light source and the photoelectric cell.

Furthermore the position of the conduits in relation to the evacuation chamber and that of the slidable block orifices is determined so that the open end of the latter when it moves towards the outlet chamber under the influence of the water current, disengages slightly the conduits, before its orifices are disengaged from the internal wall of the water circulation passage and they open into the evacuation chamber. In fact, the position of the light conduits and the slidable block orifices is chosen so as to command the starting up of the pulse generator, by the intermediate means of the photoelectric cell, before the water circulates in the evacuation chamber.

It is to be noted that the light conduits, at the end opening into the central water circulation passage, are sealed in a watertight manner but allowing rays of light to pass by means of ports of transparent or translucid material. In another embodiment, the sealing can be made by a glass or translucent or translucid material cover, engaged and fixed in a watertight manner into the water circulation passage, the cover serving then as a sheath in whigh the slidable block slides. The photoelectric cell, for its part, can be made up of a photo-conductor diode in the form of a small cylinder of roughly equal diameter to that of the light conduits at their internal end.It is to be noted that, in order to complete the watertightness of the light conduits at the level of the housings of the photoelectric cell and the light source, the latter are each enlosed in a wateright capsule made up of a transparent cupola, situated on the side of each transparent or translucid seal of the light conduits, and of a base plate on which the cupola is fixed in a watertight manner, the cupola being engaged in the housing corresponding at the outer end of each conduit.

The apparatus which has just been defined according to a first embodiment of the invention comprises the flow sensing device mounted on the outlet for treated water of the circulation reservoir but, in order to make the device even more compact, the inventor has conceived, according to a second embodiment, the flow sensor being housed directly on the end of the reservoir outlet. Consequently and according to the invention, the de-scaling apparatus is made up as in the former of two assembled casings, the casing of the box containing the electronic generator having its electrical connections to electrodes, plugged into those corresponding connections passing through the upper wall of the elongate casing containing the reservoir for circulating the liquid to be treated and the probe.

In this apparatus, the reservoir is made up of a metal tube mounted as a spacer between a block of opaque insulating material, provided with an axial blind bore into which a liquid inlet orifice opens and another block of translucent insulating material provided with an axial blind bore into which opens an outlet orifice for treated liquid and in which is housed, so that it can move under the pressure of the current of the treated liquid, a slidable block which forms an integral part of the flow detector of the latter, the said slidable block is mounted in a creeping manner on the said probe, which is made up of a metal shaft axially and centrally traversing the metal tube and the said blocks and provided at its two screwthreaded ends by securing nuts allowing the latter to screw onto the ends of the tube.

In a more specific manner and according to the invention, each of the blocks of insulating material is provided with a circular groove, concentric to the said blind bore, in which is engaged the corresponding end of the metallic tube interposed between an angular joint for waterproofing, so that the blind bore is in the continuation of the ends of the tube, the respective in-let or out-let orifices of the liquid being situated perpendicular to the bore. In addition, each blind bore is provided with a diameter sufficient to ensure the required flow through of the liquid, in spite of the presence of the shaft making up the probe which traverses it axially.

Moreover, the block in which the slidable block is housed is provided with two blind holes situated in extension one to the other, in a perpendicular plane to the said blind bore of the block and eccentric in relation to the bore, one of the holes being adapted to receive a light source and the other hole, a photoelectric diode, the source and diode making up another part of the flow sensor, these holes being situated so that the light beam emitted by the source can be cut by the slidable block when it is in a rest position and opens the said outlet orifice, and so that the beam progressively comes to strike the screen of water evacuation orifice in order to form an outlet chamber of greater cross-section, making space between its internal wall and the external wall of the slidable block when it (the slidable block) penetrates there under the influence of the water current, for a rim of cross-section at least equal to that of each of the intake and evacuation orifices and of the central bore proper, the latter being provided with identical cross-sections. On the other hand the outlet chamber is provided, beyond the outlet orifice with a closing cap mounted in a watertight manner and onto which bears one end of the return spring, the other end of the spring bearing on the closed end of the slidable block facing the cap.

Moreover, the block in which the slidable block is housed is provided with two blind holes situated in extension one to the other, in a perpendicular plane to the said blind bore of the block and eccentric in relation to the bore, one of the holes being adapted to receive a light source and the other hole, a photoelectric diode, the source and diode making up another part of the flow sensor, these holes being situated so that the light beam emitted by the source can be cut by the slidable block when it is in a rest position and opens the said outlet orifice, and so that the beam progressively comes to strike the screen of engaged in their corresponding sockets 5 and 6.

In order to dismantle the probe S and extract it from the reservoir C, for cleaning for example, it is necessary firstly to remove the box 1. This causes automatic disconnection of the supply to the electrodes and thus avoids the risk of an operator being electrocuted, if he has inadvertently forgotten to switch off the supply current to the transformer T.

As can best be seen in Figure 1, although it is shown schematically, the reservoir C is designed with dimensions such that its length equals about four times its internal diameter and comprises two orifices 11, 12 in its side wall either one of which serves as a water inlet and the other as a water outlet. The orifices are connected in a water-tight manner to union collars 13, 14 of the water pipe system, the union collars passing through the side wall of theshousing 2.

Furthermore, the reservoir contains a helical strip or worm 1 5 through the center of which the probe S passes. The worm 15 is made from insulating material which is resistant to deformation by heat and is designed with a pitch p to provide a rate of water approximately equal, but no less, in cross-section to that of the intake water pipe system while increasing the circulation and treatment of the latter.

Moreover it will be noted that a monitoring light 1 6 is provided on the lid of the box 1 to indicate, when it lights up, that the apparatus is functioning following a command for water through-flow by a user at one of the taps supplying the pipe systems for cold water or for hot water.

The upper wall of the box 1, carries a housing 1 7 for fuses for the electrical supply to the apparatus to provide easy access and replacement.

In a variant embodiment of the present invention, not shown in the drawings, the apparatus is similar in its assembly to that of Figure 1 but includes the following modifications.

The probe S is provided at its upper end with an extension in the form of a peg, adapted to engage in a corresponding socket situated inside the box 1 adjacent the bottom of the recess 10 of the latter. The socket is adapted to form one terminal of the pulse generator and thus, when the probe peg is fitted into the socket a direct link is achieved, the pins and sockets previously described in relation to Figure 1 then connecting the other terminal of the generator to the reservoir. It is to be noted that the said peg serves, in addition, as a centering means for the box 1 when mounting the latter on the housing 2.

In addition, in this variant embodiment, another connector with female sockets secured in the bottom of the box 1 and male pins projecting from the corresponding wall of the housing 2, is adapted to serve as an electrical link between the pulse generator, through the terminals 3, 4, and the water flow sensor.

In this case, the electric conductors situated inside the housing 2 link the said male pins to the female pins. It is evident that, in this case, the conductors C3, C4, as shown in Figure 1 projecting laterally from the box 1, are omitted.

As is shown in Figure 2, the generator is adapted to provide split polarised pulses to a secondary of the transformer T by way of a triac TX operated in phase.

In normal operation, the electrode S is negative in relation to the other electrode formed by the reservoir C. The peak current flowing across the electrodes is sensed by the diode D3 and charges the condensor C1.

The generator also incorporates a polarity reversal device intended to induce the automatic cleaning of the probe S and comprising a threshold sensor DS. As the probe becomes charged with non-encrusting scale, the current across the electrodes diminishes to a level at which Cl discharges faster than it is charged, thus switching the sensor DS made up of 1C1 and 1C2 and the diodes D1 and D2. The polarity of the pulses applied to the electrodes is then reversed causing the scale deposit on the probe to fall away and, as the deposit falls away from the probe, the current across the electrodes increases reversing the sensor DS and returning the circuit to normal operation.

In addition the generator is provided with a manual operation switch having three positions Cleaning, Automatic, De-scaling, so that in the event of the automatic functioning failing it is possible to operate the cleaning or de-scaling sequence, the latter corresponding to normal working.

Moreover, where the frequency of pulses is arranged to vary with respect to the through-flow of water, the generator is provided, as shown in Figure 2, with an oscillator unit OSC the terminals 3, 4 of which are linked to the flow sensor (not shown). It must be noted that the oscillator is connected in such a way that, if the flow sensor is working normally, it will vary the pulse frequency with respect to the through-flow of water, but, on the other hand, if the sensor is faulty, the pulse generator will continue working, but the pulse frequency will remain constant.

The flow sensor, shown schematically in Figure 3, comprises a substantially T-shaped body of non-magnetic material having a flow passage connecting an inlet 22 to an evacuation orifice 23. The passage has a cylindrical bore 24 in which is mounted in creeping adjustment a slidable block 25 of magnetic material, such as, for example, magnetic stainless steel. The slidable block 25 is in the form of a blind bore sleeve 26 urged by a spring 27 towards a rest position in which the sleeve 26 closes the water evacuation outlet 23. The spring 27 is housed in the blind bore of the sleeve 26 and bears at one end on the inside of the bottom wall 28, whilst its other end bears on a screw-threaded cap 29 which closes in a watertight manner an orifice 30 situated at the end of the body opposite the water inlet 22.On this end of the body, which is of greater diameter and has a larger bore than the bore 24 in which the slidable block moves, is mounted a winding B linked by electrical conductors 31 and 32 to the pulse generator of the apparatus (not shown) with which it can co-operate.

The slidable block 25 has a flange 33 adapted to slide in creeping (slidable) adjustment in the bore adjacent to orifice 30, following a rectilinear path corresponding to the thickness of the winding and allowing the maximum retraction of the slidable block from the water passage connecting the inlet 22 and outlet 23 evacuation.

It is to be noted in addition that when the slidable block is in a rest position and closes the passage, the flange 33 abuts a shoulder 34 formed between the two bores. Moreover the sidewall of the slidable block 25 has several escapement holes 35 and 36.

The working of such a flow sensor is easy to understand. As water flows through the sensor the water pressure acts on the base of the slidable block 25 urging it towards the screw-threaded cap 29 and compressing the spring 27. The movement of the block 25 into the winding B, causing a variation in the frequency of the oscillator OSC and thus generated by the pulse generator of Figure 2.

When the flow of water through the sensor ceases the water pressure reaches a state of equilibrium in the passage and the slidable block is returned to its rest position by the spring 27.

The flow sensor of Figure 4 has a housing 46 which has a longitudinal central bore 41 forming a water circulation passage, linking an inlet orifice 42 connected to the reservoir C, to an evacuation orifice 43. A slidable block 44, is located in the passage and is biassed towards a rest position by a return spring 45. As is shown, housing also has a transverse passage extending perpendicularly to the water circulation passage, the transverse passage being divided into two conduits 47 and 48 by the circulation passage.

The housing 46 is preferably cylindrical or in the form of a polygonal cross-section prism and is made from PVC material, as is also the slidable block 44 and the spring 45.

The inlet 42 and outlet 43 open laterally of the passage 41 which in addition has two further orifices 49, 50 at its extreme ends. These are tapped and closed in a watertight manner by filling and/or drain plugs 51,52 respectively.

Moreover, the plug 51 also serves as an abutment for the return spring 45.

The spring is housed in a chamber 53, situated adjacent the outlet orifice 43, and formed by an enlarged portion of the passage 41. The head of the slidable block 44 is urged into the chamber 53 by water pressure against the spring 45.

The slidable block 44 is formed by a sleeve closed at its end nearer to the outlet orifice 43, by a bottom wall 54 onto which the spring 45 bears and which has a flange 55 limiting its penetration into the passage 41 in the direction of the inlet 42. The sleeve 44 is open towards the inlet 42 and has in its side wall, situated at the same level, ~~several water passage orifices 56, the crosssections of which are so chosen that their total cross-section approximates to that of the passage 41 and of each of the identical bores 57 and 58 extending respectively the orifices 43 and 42.The position of the orifices 6, is chosen, in addition, so that when the latter move under the pressure of the water flowing in the direction of the chamber 53, each orifice 56 will begin to open into this chamber after the beginning of the disengagement of the conduits 47 and 48 by the lateral wall of the slidable block.

The light conduits 47 and 48 are each closed by a port 59 which is made up of transparent or translucent material, fixed in a watertight manner by means of a sleeve 60 screwed into a housing 61 extending towards the outside of each light conduit. In each housing 61 is mounted a capsule 62 made up of a transparent or translucent cupola 63, fixed in a watertight manner into a base plate 64 itself watertight and carrying electrical conductors (not shown) linked to the pulse generator. The conductors pass through a connecting box in the form of a commutator (not shown) fixed onto or adjacent the housing.

The two capsules 62 contain respectively, in one a light source and in the other a photoelectric cell, which can be in the form of a photoconducting diode being a small cylinder in shape with a diameter slightly less than that of each of the light conduits 47 or 48. It is to be noted that the diameter of the conduits is identical to that of the orifices 56 of the slidable block.

In addition it will be noted that, as is shown, the base plate of each capsule is screwed into its corresponding housing, but can alternatively be, although not shown, retained in the housing, by means of a half collar (ring) in the form of a pair of callipers the arms of which can be immobilised, housing the electrical conductors coming from the respective base plates of the light source and the cell and linked to the commutator.

Moreover, it will be noted that the commutator is so adapted to be able to switch the light source and cell out of circuit, in the case of malfunction of one and/or the other, as well as to close the command circuit of the pulse generator, which will then function independently of the throughflow of water and will deliver a constant pulse frequency during the replacement of the faulty part.

Following this description, it is easy to understand the working of the sensor. In fact, when there is no demand for water, that is to say no circulation of it through the passage 41, the slidable block 44 remains at rest and obscured by its lateral wall the conduits 47 and 48. When a demand for water is made, water pressure builds up and acts on the inside of the bottom wall 54 of the block 44 urging the latter into the chamber 53 by compressing the spring 45. When the slidable block moves, it firstly begins to cut off the conduits reducing the strength of the light beam from the light source which strikes the photoelectric cell which then operates the beginning of the functioning of the pulse generator.Then, as the conduits are more and more disengaged by the lateral wall of the slidable block, the orifices 56 progressively and simultaneously open into the chamber 53 and water circulation is established from the inlet orifice 42 to the evacuation orifice 43, the generator providing a progressively increasing frequency of pulses to the reservoir C and probe S, with respect to the through-flow of water.

It is to be noted that, in order to provide sufficient flow-through of water charge, the chamber 53 has a diameter which has been chosen so that when the slidable block 44 has penetrated the chamber to open its orifice 56 to the maximum, a flow-through of water of similar if not greater cross-section than that of the passage 41 or of the orifice 57 exists between the external lateral wall of the slidable block and the interior lateral wall of the chamber.

To improve the watertightness of the transparent seals of the conduits, and at the same time to increase the ease of sliding of the slidable block in the passage 41, it is envisaged, the passage 41 may be closed internally by means of a tube 65, in a transparent or translucent material, secured by means of annular joints in a watertight manner, as is shown by dotted lines in Figure 4.

As is shown in Figure 5, an apparatus according to a second embodiment of the present invention comprises two housings 101, 104 detachably assembled together. One of the housings 101, is elongate in shape and encloses the circulation reservoir 102 for the liquid to be treated with the treated liquid flow sensor 103 mounted above. The other housing 104, is in the form of a box, and contains the electronic generator (not shown) applying, under the command of the sensor 103, peak electrical pulses across the electrodes, by the intermediate means of a plug 105 situated at the junction of the two housings. One of the electrodes comprises the body of the reservoir 102 and the other electrode comprises the probe 106 mounted coaxially of the latter.It is to be noted that the box 104 is provided with an indicator light 107, with a potentiometric control button with respect to the resistance of the liquid to be treated, particularly hot or cold water and with an entrance 109 for the electrical supply conductors of the apparatus.

The reservoir 102 for the circulation or treatment of liquid comprises a metal tube 110, mounted as a spacer, between a block 111 of insulating material, provided with an axial blind bore 112 into which opens a liquid inlet orifice 113 furnished with a union 113', and another block 114 of translucent insulating material, provided with an axial blind bore 115 into which opens an orifice 11 6 for the outlet of treated liquid provided with a union 1163. In the blind bore 115 is housed a piston 11 7 mounted in a slidable manner on the probe 106 and forming an integral part of the flow detector.The probe 106 is made up of a metal rod coaxial with the tube 110 and the blocks 111,114 and the screw ends of which open into the bottom of the said blind bores 112,115 through the holes 118,119 which are each provided with a watertight joint. In each of the blocks 111,114 is cut a groove 120, 121 which is concentric to the blind bore in which is engaged the corresponding end of the tube 110 with the interpositioning of an annular joint 122, 123 respectively. The blocks are thus assembled in a watertight manner on the tube and screwed into position by means of securing screws with self-locking washers (stops) with which the ends of the shaft or probe 106 are provided.It is to be noted that the end of the probe, forming one of the electrodes of the apparatus, opposite the flow sensor 103, is linked to the plug 105 by means of an electrical conductor 124, the tube 110, forming the other electrode, itself being linked to the plug by an electrical conductor 125.

Moveover, as can be readily seen in Figures 5 and 6, the block 114 containing the piston 117 is provided with two blind bores 126, 127. These bores 126,127 are coaxial extending perpendicular to the blind bore 11 5 of the block, and eccentrically of the axis thereof. The bore 126 is adapted to receive a light source 128 linked by an electrical conductor 129 to the plug 105, and the bore 127 is adapted to receive a photoelectric diode 130 linked by a conductor 131 to the plug 105, which, as has been described before, is linked to the pulse generator (not shown) enclosed in the box 104. It is to be noted that the bores 126, 127 are situated so that the light beam emitted by the source 128 is blocked by the piston 11 7 when this is in its rest position.As liquid flows from the inlet 113 to the outlet 11 6 the pressure urges the piston 11 7 upwardly, progressively uncovering the diode 130 to the beam. It must be noted that the piston 11 7 is maintained in a rest position or turned to this position when liquid flow ceases, by means of a compression spring 132 coaxial on the shaft forming the probe 106 and housed in the blind bore 11 5 between the bottom of the bore and the piston. The latter in its rest position abuts onto a stop washer 133 secured to the probe 106.

In the embodiment shown in Figures 5 and 6, the piston 117 is annular and its internal surface is provided with axial, acute angled ribs 134 in contact with the shaft forming the probe 106. The external surface of the piston also has longitudinally extending channels which have their ends, nearest to the stop washer 133, linked together by a circular flange 136 forming a fine and supple lip closing the groooves of the channels and rubbing on the inside of the blind bore 115.

In another embodiment, shown in Figure 7 and 8, the piston 11 7' is in the form of a sleeve 137 mounted in slidable adjustment on the probe 106 and carrying a washer 138, the machined outer edge 136 of which is provided to rub gently on the inside of the bore 11 5. The sleeve 137 is also provided with a lateral and longitdinally extending fin 139, adapted to be able to slide in a longitudinal groove 140 of the bore 11 5 and to form an opaque screen for the light beam emitted by the source 128.As can easily be seen in Figure a, the blind bores 126', 127' housing respectively the light source 128 and the photoelectric diode 130, are situated perpendicularly to the groove 140 and their bases are very close to the lateral sides of the groove, this allowing the length of projection of the light beam onto the receptor screen of the diode to be diminished to the maximum.

As is shown schematically in Figure 9 the apparatus which has just been described can be connected in series with another of the same type inside the same housing, when one requires a double treatment of liquid. In this case, only one of the apparatus is provided with a flow sensor 103. The orifices 113 formerly called inlet orifices, become communcation orifices between the two apparatus by the intermediate means of a linking conduit 141. The orifice 11 6 formerly described as the outlet orifice becomes the only liquid inlet orifice on the apparatus without the flow sensor, and the orifice 11 6' of the other apparatus carrying the sensor, becomes the only outlet orifice for liquid which has undergone a double treatment.

As is shown schematically in Figure 10, the apparatus according to the present invention can also be connected in parallel with another apparatus when one requires double the throughflow of treated liquid. In this case, the two apparatus used are the same as in the double treatment as defined in relation to Figure 9, but the linking conduit 141' carries a T union connected to the liquid supply pipe system 142, and the orifices 116 and 116' both become treated liquid outlet orifices and are linked together by a conduit 143 which carries also a T union connected to the treated liquid outlet pipe system 114. It is understood that the pipe system 142 and 144 are envisaged to have a crosssection at least double that of the conduits 141' and 143.

Claims

1. Apparatus for purifying or softening a liquid, comprising an elongate reservoir closed at both ends and serving as an electrode, a second electrode formed by a probe extending through one end wall of the reservoir into the latter and being secured to said end wall in a liquid tight and insulating manner, a pulse generator operable to apply a pulsed current to said electrodes, a sensor located adjacent an outlet of the reservoir for sensing the flow of treated liquid and controlling said generator in dependence thereon; and wherein said reservoir is enclosed in an elongate first housing to one end wall of which is secured a bottom wall of a second housing containing said generator, the arrangement being such that access to said probe is effected only by disengaging said first and second housings.

2. Apparatus according to claim 1 further comprising at least one connector having cooperating pins and sockets connecting said electrodes to said pulse generator through said one wall and said bottom wall, wherein disengaging said first and second housings disconnects said pins from said sockets.

3. Apparatus according to claim 1 or 2, wherein the length of the reservoir is approximately equal to four times its internal diameter, and comprises a lateral, liquid close inlet and outlet adjacent respective ends thereof, each of which is connected in a watertight manner to a pipe union in a pipe system traversing the corresponding lateral wall of the first housing.

4. Apparatus according to claim 3 wherein the interior of the reservoir is formed into a helical passage by a strip or worm of insulating heatresistant material helically wound about the second electrode, the respective ends of said passage lying adjacent said inlet and outlet, and wherein the pitch of said strip or worm is such as to provide a race of liquid in section approximately equal to but no less than that of the inlet pipe system for liquid to be treated for increasing the path of circulation and treatment of the liquid.

5. Apparatus according to any of claims 1 to 4, wherein the pulse generator is operable to generate polarised pulses, split at the secondary of a transformer by triac operated in phase and comprising a polarity reversal device for initiating automatic cleaning of the said probe, and wherein the device comprises a threshold sensor operable to sense the current flowing between the electrodes and to reverse the polarity of said pulses in response to said current dropping below a preselected value and to reverse again said polarity in response to said current rising above said value.

6. Apparatus according to any of claims 1 to 5 further comprising a filter for trapping and eliminating scale for avoiding an influx of nonencrusting scale in the treated water evacuation pipework following the automatic cleaning of the probe.

7. Apparatus according to claim 1 wherein the end of said probe outside said reservoir has a peg adapted to engage in a socket located in the second housing, the socket being linked to the terminal of the pulse generator intended to supply electricity to the probe, so that when the peg is engaged in the socket when the second housing is mounted on the first housing, not only is the probe supplied directly but also the second housing is centred on the first housing.

8. Apparatus according to claim 5, wherein the pulse generator further comprises an oscillator for providing said pulses, the frequency of oscillation of which is controlled by said flow sensor.

9. Apparatus according to claim 8 wherein the oscillator is connected to the flow sensor, by a plug and socket connector, one of said plug and socket being mounted in the bottom wall of the second housing and the other being mounted in the end wall of the first housing.

10. Apparatus according to any of claims 1 to 9, wherein the flow sensor comprises a housing of non-magnetic material having a liquid circulation passage linking an inlet to an evacuation orifice thereof, and in which under the pressure of the liquid flow and against the force of a return spring, a slideable element or a slideable block of magnetic material, is adapted to move, and wherein the housing is in the shape of a comprising, at the end of two of its perpendicular branches, the inlet and evacuation orifices respectively, the water circulating passage thus being at right angles, and the end of the third branch, opposite the inlet orifice, being provided with an external winding, connected by electrical conductors to the pulse generator, the said slideable block being adapted to directly penetrate progressively into the third branch of the T and from there, into the hollow core of the winding, under the pressure of the liquid flow, while progressively opening the passage towards the evacuation orifice in proportion to the increase in liquid through-flow.

11. Apparatus according to claim 10, wherein the slideable block of its sensor comprises a blind bore cylindrical sleeve, in which is housed the spring adapted to urge the slideable block towards a rest position against the liquid flow pressure, the slideable block at its base, opposite the inlet orifice, provided with the same diameter as the passage at right angles in order to be able to slide in creeping adjustment in the part of the passage corresponding to the inlet orifice, the slideable block also having also a very slightly greater length than the diameter of the part of the passage corresponding to the outlet orifice and being provided in its lateral wall with several escapement holes, situated nearer to its base than to its open end so as to be at the level of the evacuation orifice when it is in a rest position.

12. Apparatus according to any of claims 1 to 9 wherein the flow sensor mounted on the outlet comprises a housing, preferably a hard plastics material of the PVC type, housing a liquid circulation passage linking an inlet or outlet orifice of the reservoir to an evacuation orifice onto which is connected the treated water outlet pipe system, a slideable block also of hard plastics material, adapted to move in the passage under liquid pressure, and restrained by a return spring in order to regain its rest position when the pressure ceases, the housing being in the form of a right prism of polygonal cross-section or of a cylinder provided with a longitudinal central bore forming the passage and comprising on either side of the bore two housings situated at the same level between the water inlet and outlet orifices, the housings being adapted to contain in one a light source and in the other a photo electric cell so placed as to be struck by the light beam from the source perpendicularly traversing the said bore, the slideable block being so arranged that, in a rest position, it cuts, by making a screen, the said light beam, at the same time as it moves towards the evacuation orifice, it allows the said beam to pass progressively, and to strike the photo-electric cell connected to the pulse generator.

13. Apparatus according to claim 12, wherein the slideable block of the sensor is in the form of a blind bore sleeve, the open end of which is situated beside inlet orifice, at the same time as its closed end compresses the return spring, and the lateral wall of which is provided with several liquid passage orifices cut out close to the closed end, the position of these orifices as well as the length of the slideable block being so envisaged that, when the latter moves towards the evacuation orifice, it disengages the said light beam at the same time as its passage orifices are put into communication with the evacuation orifice.

14. Apparatus according to any of claims 12 or 13, wherein the passage of the sensor, formed by the central bore in which the slideable block slides, is bored out in the part corresponding to the water evacuation orifice in order to form an outlet chamber of greater cross-section, cut out between its internal wall and the external wall of the slideable block, when the slideable block penetrates it under the influence of liquid pressure, an area of cross-section at least equal to that of each of the inlet or evacuation orifices and of the central bore, the latter being envisaged to have identical cross-sections, the evacuation chamber being provided beyond the evacuation orifice with a closing cap, mounted in a liquidtight manner and on which one end of the return spring bears, at the same time as the other end of the latter bears on the closed end of the slideable block opposite the cap.

15. Apparatus according to any claim 12 to 14 wherein there is provided in the flow sensor a transverse light conduit to link the respective housings of the light source and the photoelectric cell, and situated so that it is obscured by the lateral wall of the slideable block when this is in a rest position, the light conduit which is cut so as to be perpendicular to the bore forming the passage and to pass through the center of it, being divided into two lateral conduits by the said bore and the ends of each of these opening into the latter being provided with an identical or slightly greater diameter than that of each of the passage orifices of the slideable block, at the same time their opposite ends are further bored out of house respectively the light source and the photo-electric cell.

16. Apparatus according to claim 15 wherein in the flow sensor, the position of the light conduits and of the liquid passage orifices of the slideable block is chosen in order to command the starting of the pulse generator, by the intermediate means of the photo-electric cell, before the liquid circulates in the evacuation chamber, the light conduits at their ends which open int the central water circulation passage being sealed in a liquid-tight manner, but allowing the light rays to pass, by means of ports made of transparent material or of a glass cover, which is engaged and fixed into the said passage and forms a sheath in which the slideable block slides.

17. Apparatus according to claim 1, in which the treated liquid flow sensor controlling the pulse generator is situated in the end of the outlet of the circulation and treatment reservoir, wherein the reservoir comprises a metal tube mounted as a spacer between a block of opaque insulating material, provided with an axial blind bore in which a liquid inlet orifice opens, and another block of translucent insulating material provided with an axial blind bore into which a treated liquid outlet orifice opens and where is housed so that it can be moved by the pressure of the current of treated liquid, a slideable block which is an integral part of the flow sensor of the latter, which slideable block is mounted in a slideable manner on the said probe, which comprises a metal shaft which traverses axially and centrally the metal tube and the said blocks, and is provided at its two screw threaded with securing nuts allowing the latter to be screwed onto the ends of the tube.

18. Apparatus according to claim 17, wherein each of the said blocks of insulating material is provided with a circular groove, concentric to the said blind bore, into which is engaged the corresponding end of the metal tube with the interposition of an annular liquid sealing joint, so that the blind bore is in the extension of the ends of the tube, the respective liquid inlet or outlet orifice being situated perpendicular to the bore.

19. Apparatus according to claim 17 or 18, wherein the block in which the slideable block is housed is provided with two coaxial blind bores extending perpendicular to the said blind bore of the block and eccentric in relation to the bore axis, one of the bores being adapted to receive a light source and the other bore, a photo-electric diode, the said source and diode comprising another part of the flow sensor, the bores being situated so that the light beam emitted by the source is cut by the slideable block when it is in a rest position and closes the said treated liquid outlet orifice, and so that the beam progressively comes to strike the screen of the diode when the slideable block, pushed by liquid flow pressure, progressively moves with respect of the through flow of liquid required and disengages the said outlet orifice.

19. Apparatus according to claim 17 or 18, wherein the block in which the slideable block is housed is provided with two coaxial blind bores extending perpendicular to the said blind bore of the block and eccentric in relation to the bore axis, one of the bores being adapted to receive a light source and the other bore, a photo-electric diode, the said source and diode comprising another part of the flow sensor, the bores being situated so that the light beam emitted by the source is cut by the slideable block when it is in a rest position and opens the said treated liquid outlet orifice, and so that the beam progressively comes to strike the screen of the diode when the slideable block, pushed by liquid flow pressure, progressively moves with respect of the through flow of liquid required and disengages the said outlet orifice.

20. Apparatus according to any of claims 17 to 19, wherein the slideable block is recalled to a rest position when the liquid current ceases, by a compression spring engaged on the shaft forming the probe and housed between it and the bottom of the blind bore, a stop in the form of a stop washer being provided on the shaft to stop the slideable block in a rest position.

21. Apparatus according to any of claims 17 to 20, wherein the slideable block comprises a ring the bore of which carries acute angled ribs in contact with the shaft, the ring being provided with external longitudinal channels, which have their ends, nearest the shaft, linked together by a circular flange which forms a fine and supple lip closing the grooves of the channels and adapted to gently slideably rub on the interior of the blind bore.

22. Apparatus according to any of claims 17 to 21, wherein the slideable block comprises a tubular sleeve which carries a washer, the machined down edge of which rubs on the inside of the blind bore, provided longitudinally and laterally with a lug conceived to slide in a groove longitudinal to the blind bore and forming an opaque screen cutting the said light beam when the slideable block is in a rest position, and disengaging it when the latter moved under the influence of the liquid current, the said blind bores housing the light source and the photo-electric diode respectively being situated perpendicularly to the groove with the base very close to the lateral sides of the groove in order to reduce to the maximum the length of the light beam.

23. Apparatus according to any of claims 1 to 22, adapted to produce a double treatment of liquid supplied, comprising two series connected liquid circulation reservoirs, only one of which comprises the flow sensor, the inlet orifices being connected together by a conduit, at the same time, the orifice initially defined as outlet to the apparatus deprived of the sensor becomes the only liquid inlet orifice, the liquid outlet orifice being that provided on the apparatus carrying the said sensor.

24. Apparatus according to any of claims 1 to 22 adapted to double the through flow of treated liquid, comprising two parallel connected reservoirs only one of which carries the flow sensor, the liquid circulation reservoirs having the inlet orifices connected together by a T union fixed onto the liquid intake pipe system, and the treated liquid outlet orifices connected in the same manner onto a T union fixed onto the outlet pipe system, the supply and outlet pipe systems having, in this case, a cross-section twice as great as that of each of the inlet and outlet orifices.

New Claims or Amendments to Claim filed on 26 June 1980.

Superseded Claim 19 New or Amended Claims:~