DE102005044252A1 - Apparatus to soften water, using an electrical field, has exchangeable electrodes to set the operation according to the nature of the water being treated - Google Patents

Abstract

The apparatus to treat water using an electrical field has a chamber for the water flow, with a number of longitudinal hollow zones for exchangeable electrodes (140) giving a voltage between them. At least two electrodes are for different water. At least one electrode contains orthophosphate and at least one electrode contains graphite. The electrode can have a diamond coating.

Description

technical area

The The invention relates to a device for water treatment by means of an electric field containing a treatment chamber through which the water to be treated flows with multiple, elongated cavities in which interchangeable Electrodes are arranged, between each of which a voltage can be applied.

Drinking water contains important minerals, including calcium and magnesium carbonates, in sum, also called water hardness. These Minerals are on the one hand for the health very important. On the other hand, in the drinking water installation, especially when heated, to technical faults to lead.

at the warming, e.g. in the drinking water heater, it comes to the formation of insoluble Lime deposits, also called scale. This scale forms on the warm side of the installation. It impairs heat transfer. In Pipes can scale over the years to a tube infarction, i. to a closure in the the drinking water heater lead downstream pipe installation.

Around To avoid such lime deposits, it is known to soften the Make drinking water, in which the minerals from the drinking water be removed. Such softening is via ion exchange or reverse osmosis possible.

The avoids scale formation. But that will be in other ways the quality of drinking water by the removal of itself in the drinking water desired Minerals impaired.

It are methods for the treatment of drinking water by means of so-called. Electrophysical Devices known, in which a crystal nucleation in the drinking water are effected should. The seed crystals called seed crystals are used in the Drinking water carried. The conglomeration of the seed crystals then leads to the so treated Drinking water less to deposits in pipes or heating elements in Form of scale leads, while On the other hand, the minerals in the drinking water are preserved.

The treatment by means of electrophysical devices essentially follows the following principle: In drinking water, a certain amount of carbon dioxide (CO ₂ ) is always dissolved. This carbon dioxide forms a reaction equilibrium with the remaining components, wherein calcium hydrogen carbonate Ca _{(HCO3) 2} is formed of calcium carbonate CaCO ₃ according to the reaction equation: CaCO ₃ + H ₂ O + CO ₂ ⇔ (Ca (HCO ₃ ) ₂ ) When the water is heated, CO ₂ escapes from the water and scale is formed. But you can also change the corresponding lime-carbonic acid balance in the drinking water according to the equation.

Leading carbonic acid in the water too, so dissolves a shift of the equilibrium to the left in the above formula out. From the hydrogen carbonate present in the water form Germs of calcium carbonate (calcium supersaturation). The further formed calcium carbonate is then preferably on the germs once formed, i. the germs "grow".

These Reaction takes place in a treatment chamber with a cathode and an anode electrolytically by local changes of the pH. The seed crystals form at the cathode pH increase. The seed crystals must then after appropriate growth again the drinking water by lowering be added to the pH at the polarity reversal. Then it's already carbonate as seed crystals or germs in drinking water, if that Drinking water is heated. The seed crystals or germs need not to be reformed anymore. The carbonate sits down accordingly mainly on the entrained in the water seed or germs and no longer stuck to the installation elements.

It is still the problem of drinking water installations Corrosion. This can be counteracted by the addition of minor amounts of orthophosphate become. The addition is done with dosing. Such dosing are also used to add polyphosphate to water to bind contained lime.

Farther is it desirable in some applications Drinking water e.g. to avoid legionella, to disinfect. For this purpose it is known to irradiate the water with UV rays or the water-containing chloride or ionized oxygen to be disinfected by electrolysis, atomic chlorine or oxygen to oxidize.

at again other applications in the spa, it is desirable To add magnesium to the water.

For each of these Water treatment forms are used independent devices as needed in the desired Combination can be used in the installation. This is expensive.

In the EP 1 284 239 A2 discloses a device for water treatment in which graphite electrodes are arranged in pairs in elongated interconnected cavities. The cavities are flowed through by the water to be treated. The device is used only to reduce limescale.

From the DE 20 2005 003 691 U1 For example, a water treatment apparatus is known which reduces limestone formation by means of electrophysical treatment on graphite electrodes. Furthermore, the device is used to disinfect the water. This is done by electrolytically generated disinfectants, such as chlorine, hypochlorous acid and oxygen, which are contained in the water and activated by electrolysis. The cathode is brush-shaped. The anode is formed in a first region of graphite felt and in a second region of platinum-plated titanium wire or the like.

In the DE 100 20 437 A1 For example, a method of reducing scale formation and / or corrosion in liquid-carrying systems is described. The magnesium content is increased at the expense of, in particular, the calcium content.

It is also known, a water treatment for the purpose of reducing to carry out corrosion. The water is permanently orthophosphate in small quantities added. The dosage is done with dosing devices, as under the Trade name HabeDos are sold by the company Honeywell GmbH.

Out the publication T. Turuta, H. Tanaka, Y. Nishiki, L. Pupunat, W. Haenni, Ph.Rychen "Legionella inactivation with diamond electrodes "in Diamand and related materials 13 (2004) p. 2016-2019 (Elsevier) is the deactivation of Legionella known by diamond-coated electrodes.

epiphany the invention

It Object of the invention to provide a device with which a Water treatment feasible which is adapted to individual requirements. According to the invention Task solved by that at least two of the electrodes for different water treatments are formed. This means that even a pair of electrodes out Electrodes with different functions can exist. So it can always the electrodes in the device be installed, which just meet the requirements. It can for every application the same device is used. Because the Electrodes are interchangeable, can These can be individually adapted to the case of need. By the different use cases reduces the production cost. Only the electrodes have to be different be trained while that Casing, the voltage source and the connections remain the same.

at such a device At least one of the electrodes may comprise orthophosphate, which when a voltage in the water is deliverable. The electrode may consist of graphite which is immersed in an orthophosphate-containing solution has been. With such electrodes can In addition to avoiding calcification, corrosion can also be reduced.

at Another type of application is at least one of the electrodes made of a material which is an electrolysis of in the treated water containing chloride and / or oxygen ions and / oxygen radicals allowed. In this way, in addition to the calcification protection and / or corrosion protection and disinfection of the water done. For this Purpose is a diamond coated electrode or an electrode made of stainless steel.

For another Application example comprises at least one of the electrodes magnesium and / or Magnesium compounds, which upon application of a voltage in the Water is deliverable. These electrodes are suitable for applications where an elevated Magnesium content desired is. It can be replaced by the electrode replacement of limestone Compounds caused by magnesium and / or magnesium compounds become. In this way, at the same time a reduction of calcification causes.

In In one embodiment of the invention, the electrodes are rod-shaped and arranged in pairs parallel to each other, and extend at a distance from each other through the said, elongated Cavity. One end of the cavity is with a water inlet and the other end of the cavity connected to a water outlet, causing a water flow from one electrode to another substantially transverse to the longitudinal axis the electrodes can be generated. In this embodiment, a achieves a particularly compact arrangement with a fast flow, the for the Formation of crystal nuclei on graphite electrodes for reduction of lime deposits conducive is.

The rod-shaped electrodes can be easily manufactured and the arrangement is thereby less expensive than eg brush-shaped electrodes. The electrodes can be individually replaced or serviced if necessary. The invention makes it possible that in addition to the crystal growth and the formation of crystal nuclei is promoted by a large flow velocity at the cathode. By contrast, an inhomogeneous field and a long residence time are not absolutely necessary. Due to the flow transverse to the electrodes, the crystal nuclei are sufficiently rinsed off the electrodes and the electrodes can not be clogged. Even after prolonged use, no contamination or deposit can be detected within the system. A deportation of the crystal nuclei via a motor is not necessary, since the flow causes a sufficient Kristallkeimbeimischung in the immediate vicinity of the cathode.

Preferably the electrode pairs of cathode and anode are in pairs isolated against other electrode pairs. This allows the electrical Fields that form between a pair of electrodes, none Influence on the electric fields between the other electrode pairs exercise.

Preferably the electrode pairs are arranged substantially in a ring shape. In the electrode ring can be provided about 5 pairs of electrodes. Of these, 3-4 electrode pairs of graphite be. These cause a descaling of the water. The remaining 1-2 Electrode pairs can add more Uses, e.g. Disinfection, dosage of orthophosphate, magnesium or the like supplied become. In one embodiment of the invention, the electrode pairs in a substantially pot-shaped casing arranged. It can be a flow guide be provided, in which cylindrical cavities for receiving the electrodes are located. about the flow guide Thus, the individual treatment chambers and the intervening insulation realized at the same time.

In a particularly preferred embodiment of the invention exist the electrodes of a porous Material with great Surface, for example made of graphite. Due to the large surface more germs can be formed. This further improves the efficiency of the device. But they are Other electrode materials conceivable, such as activated carbon or similar.

refinements The invention are the subject of the dependent claims. An embodiment is explained in more detail below with reference to the accompanying drawings.

Short description the drawings

1 is a perspective view of a device for the treatment of water

2 is a cross section through the housing with treatment chambers and aftertreatment chamber arranged therearound

3 is a perspective view of a flow guide

4 is a cross section through the mounting arrangement of the electrodes Description of an embodiment

In 1 is with 10 a device for electrophysical water treatment called. The device includes a fitting part 12 and a water treatment unit disposed thereunder 14 , In the water treatment unit 14 A "dynamic treatment" of the flowing water by means of electric fields.This treatment crystallizes nuclei, which are carried in the water.At these crystallization nuclei, the lime dissolved in the water crystallizes so that it is carried in the form of small calcium crystals from the water and does not settle on the walls and lead to calcification Furthermore, substances can be added to the water or disinfected in a manner to be described.

In 1 is the device 10 shown in perspective. The fitting part 12 has a Y-shaped channel body 16 on. The channel body 16 has three connecting pieces 18 . 20 and 22 , Over the connecting piece 20 is the channel body 16 with the inlet 24 the water treatment unit 14 connected. The inlet 24 is part of a lid 26 that about screws 28 with a cup-shaped housing 30 connected is.

The inlet 24 forms the in 1 upper part of an input channel 34 , The input channel 34 is on the side of the housing 30 molded and over an intermediate wall 38 from the rest of the housing wall 32 enclosed space separated ( 2 ). The input channel 34 extends from the inlet 34 up to an opening 40 ( 1 ), which is the input channel 34 with the room 36 combines.

In the case of the housing 30 enclosed space 36 are four identical flow guide elements 42 . 44 . 46 and 48 intended. In an alternative embodiment, a single flow guide with four times the height is used. Small flow guide elements are lighter, however and therefore cheaper to produce.

Such a flow guide 42 is in 3 shown separately again. The flow guide 42 is made of plastic and is manufactured by injection molding. The flow guide element has a substantially cylindrical basic shape. In this basic form are also cylindrical cavities 50 . 52 . 54 . 56 . 58 . 60 . 62 . 64 . 66 and 68 intended. The cavities 50 . 52 . 54 . 56 . 60 . 62 . 64 . 66 and 68 are arranged in a substantially annular shape on the outer edge of the basic shape. The cavity 58 is located a little further inside the wreath. The longitudinal axes of the cavities are parallel to each other and parallel to the longitudinal axis of the basic shape.

Two of the cavities are connected to each other via gaps. The cavities 50 and 52 , respectively. 54 and 56 are over a gap 70 , respectively. 72 , which runs approximately in the circumferential direction, connected to each other. cavities 58 and 60 are over a gap 74 , which runs in the radial direction, interconnected. cavities 62 and 64 , respectively. 66 and 68 are each over a gap 76 respectively. 78 which in turn runs approximately in the circumferential direction, interconnected.

The middle area 80 the basic form 42 is also formed as a cavity. The cavity extends on one side 82 to the edge of the cylindrical basic shape 42 , The cylindrical cavities 54 . 58 and 64 are with the cavity 80 in the middle area over narrow gaps 84 . 86 and 88 connected. The cavities 50 and 68 are over narrow gaps 90 and 92 with the at the side 82 located edge of the basic form 42 connected.

The border area on the side 82 is by footbridges 94 and 96 in the radial direction to the basic shape 42 are formed, from the remaining edge area 98 separated over the entire length of the basic form. column 100 and 102 at the edge of the basic form 42 connect the cavity 52 with the outside of the basic form 42 located outside space. Likewise connect column 104 and 106 the cavity 56 and split 108 the cavity 60 with the outside space. column 110 and 112 connect the exterior with cavity 62 and column 114 and 16 connect the cavity 66 with the outside space. The entire flow guide is mirror symmetric to a through the aperture and the cavities 58 and 60 running diameter.

The scope of the basic form 42 also has troughs 118 extending over the entire length and distributed evenly over the entire circumference. The hollows 118 are each arranged between two columns which connect the cavities with the outer space.

In 2 is shown as the flow guide 42 in the case 30 sitting. Between the flow guide 42 and the housing wall 32 is a gap 120 , The gap 120 represents an aftertreatment chamber that extends over the entire height of the assembly. In the aftertreatment chamber ten electrodes are evenly spaced 122 arranged. Like the hollows 118 in the flow guide 42 are also troughs 124 in the inside of the housing wall 32 intended. The hollows are opposite each other. The electrodes 122 each sit in the hollows 118 and 124 and are kept in their position. In this way, no further attachment for the electrodes needs to be provided. Through the electrodes 122 becomes the aftertreatment chamber 120 divided into nine sub-chambers, which only at its upper end in the housing cover, whose interior 126 ( 1 ) simultaneously forms the outlet. However, the height of the flow guiding elements does not connect the subchambers to one another. In each case a gap from the treatment chamber opens into a lower chamber of the aftertreatment chamber 120 ,

In each sub-chamber of the aftertreatment chamber 120 is a pen 128 arranged parallel to the electrodes. The pencil 128 is cylindrical and sits approximately midway between the electrodes. The pencil 128 serves to improve the flow conditions and has a positive effect on crystal growth. The pencil 128 has a smaller diameter than the width of the gap 120 between the flow guide 42 and the housing wall 30 , The water can therefore flow past it. Every pin 128 is from a semi-annular fastener 130 held to the flow guide 42 is formed ( 3 ).

The attachment of the electrodes is in 4 again shown in detail. The electrode 140 (not fully illustrated) has a threaded hole 142 in which a metal pin 144 is screwed. The metal pin 144 leads to the contact 146 , seals 148 . 150 and 152 are provided around the metal pin. Furthermore, a seal 154 below the case bottom 156 the treatment device provided. To remove the electrode, the lid 26 of the housing 30 removed and unscrewed the electrode from above. The electrode can then be easily inspected, cleaned or replaced without affecting the electrical contact.

The described arrangement works as follows:
The water to be treated flows from the nozzle 18 of the duct body to the inlet 24 in the connecting piece 20 , From the inlet 24 the water flows through the inlet channel 34 down through the opening 40 in the middle area 80 the flow guide 42 , From there, the water spreads over the column 84 . 86 . 88 . 90 and 92 in the treatment chambers, where each pair of electrodes sit. Due to the small dimensions of the gaps and gaps, an increased flow velocity occurs in the horizontal direction 1 , ie transverse to the longitudinal axis of the electrodes.

When used to prevent calcification, the electrode pairs are made of graphite. One each as a cathode and an anode polarized electrode 131 and 133 , are subjected to a voltage that is sufficient for the nucleation. The nuclei form in the inhomogeneous field between the electrodes at the cathode. The graphite electrodes are reversed every 60 seconds. As a result, the small gap does not increase and the graphite electrodes are stressed evenly. The formed crystal nuclei become with the water by the further column, eg gap 102 in a sub-chamber of the aftertreatment chamber 120 rinsed. In the field between the graphite electrodes alternately poled as anode and cathode the germs grow further. These graphite electrodes are also reversed at intervals of 60 seconds. The water now flows in the vertical direction 1 up to one of the housing cover 26 formed cavity 126 , The cavity 126 is with an outlet 132 that in the connecting piece 22 the channel body opens, connected.

If, in addition to avoiding limestone formation, further functionalities are to be realized, individual electrodes can be used 140 be replaced. Instead of graphite electrodes, one or more diamond-coated electrode pairs can then be used. At these electrodes, a voltage is applied which is sufficient to disinfect the water. In this case, the chloride contained in the water anyway or the oxygen is activated by electrolysis. These then have a disinfecting effect.

It can Graphite electrodes are used, which were previously soaked in an orthophosphate solution or orthophosphate particles. The amount of orthophosphate and the applied voltage are chosen so that the corrosion of the Pipes and fittings in the liquid-carrying System is reduced. If the electrode no longer orthophosphate can be exchanged in the manner described above.

As The orthophosphate electrode can also other additives, e.g. Magnesium are released to the water. Separate dosing devices are no longer required.

The Arrangement is not limited to any functionality and can be addressed to the respective Requirements are adjusted by selecting the electrodes.

Claims (14)

Apparatus for water treatment by means of an electric field containing a treatment chamber through which the water to be treated has a plurality of elongate cavities in which interchangeable electrodes are arranged, between each of which a voltage can be applied, characterized in that at least two of the electrodes are designed for different water treatments , device according to claim 1, characterized in that at least one of Electrodes include orthophosphate, which upon application of a voltage in the water is deliverable. device according to claim 2, characterized in that at least one of Consists of graphite electrodes, which in a orthophosphate-containing solution was immersed. device according to one of the preceding claims, characterized in that at least one of the electrodes consists of a Material is made, which is an electrolysis of in the water to be treated contained chloride and / or oxygen ions and / or oxygen radicals allowed. device according to claim 4, characterized in that the electrode is diamond coated or stainless steel. device according to one of the preceding claims, characterized in that at least one of the electrodes is magnesium and / or magnesium compounds, which when applying a Tension in the water is deliverable. device according to claim 6, characterized in that through the electrode a replacement of limestone-producing compounds by magnesium and / or Causes magnesium compounds. device according to one of the preceding claims, characterized in that the electrodes are rod-shaped are arranged in pairs in parallel to each other, at a distance from each other by the said, elongated Cavity extend, and the one end of the cavity with a water inlet and the other end of the cavity connected to a water outlet is, whereby a water flow of one electrode to the other substantially transverse to the longitudinal axis the electrodes can be generated. device according to one of the preceding claims, characterized in that the electrode pairs of cathode and Anode are each isolated in pairs against other pairs of electrodes. device according to one of the preceding claims, characterized by a substantially cup-shaped housing. device according to one of the preceding claims, characterized in that a flow guide provided is in which cylindrical cavities to receive the electrodes. device according to one of the preceding claims, characterized in that the flow guide of electrically insulative material. device according to one of the preceding claims, characterized in that the electrodes are made of graphite. device according to one of the preceding claims, characterized by means for reversing the polarity of the electrodes.