Electrolytic cell, in particular for the disinfection of swimming pools

Abstract

The disclosure relates to an electrolytic cell comprising an inlet, an outlet and a housing containing a plurality of flat electrodes. The housing forms an annular chamber into which electrolyte can be introduced through the inlet in such a way that a rotating flow is created.

Description

[0001] Electrolysis cell, especially for swimming pool disinfection

[0002] Description

[0003] Field of the invention

[0004] The invention relates to an electrolysis cell, which is used in particular for producing chlorine or hypochlorite or bromine or hypobromite for swimming pool disinfection. Furthermore, the invention relates to a method for producing the electrolysis cell.

[0005] Background of the invention

[0006] It is known in practice to produce hypochlorite or hypobromite from a salt solution using an electrolysis cell and to use it for swimming pool disinfection. Chlorine produced by the electrolysis cell, particularly hypochoric acid HClO, acts as a strongly oxidizing agent and thus has a high disinfecting effect.

[0007] Known electrolysis cells used for swimming pool disinfection, for example, comprise a tubular housing in which an electrode package is arranged. A disinfection system with such an electrolysis cell is marketed, in particular, by the applicant under the trade name BWT Hydrolife 16.

[0008] A disadvantage of known electrolysis cells is that the efficiency is only sufficient if the water has a relatively high salt content, normally > 3 g / 1 NaCl. Object of the invention

[0009] The invention is based on the object of providing an electrolysis cell that is simply constructed and has high efficiency in terms of current yield and conversion. In particular, the invention is intended to provide an electrolysis cell that can be optimally used in a system for disinfecting swimming pools.

[0010] Object of the invention

[0011] The object of the invention is already achieved by an electrolysis cell and by a method for producing an electrolysis cell according to one of the independent claims.

[0012] Preferred embodiments and developments of the invention can be found in the subject matter of the dependent claims, the description and the drawings.

[0013] The invention relates to an electrolysis cell. The electrolysis cell is particularly designed for a system for swimming pool disinfection in order to produce free chlorine or free bromine from a chloride- or bromide-containing salt, or generally from a halide-containing salt.

[0014] The electrolysis cell comprises an inlet and an outlet, as well as a housing with a plurality of plate-shaped electrodes. The housing provides an annular space. According to the invention, the electrolysis cell is designed such that electrolyte can be introduced into the space from the inlet in such a way that a rotating flow is created.

[0015] According to the invention, the electrodes, in particular the electrode package, are not flowed around in a linear manner, but a vortex is created in the space which flows past the plate-shaped electrodes.

[0016] It has been found that this can increase the efficiency of the electrolysis cell. The inventors suspect that the vortex-like flow ensures that the electrodes are better supplied with fresh electrolyte, which increases efficiency.

[0017] The space can in particular be circular or cylindrical in shape.

[0018] The housing may in particular comprise a circular cylindrical section which provides the space and in which the electrodes are stacked.

[0019] In one embodiment of the invention, this circular-cylindrical space intersects on the shell side with a tubular housing section, which provides the inlet and outlet. Due to the intersection, the circular-cylindrical space opens into the tubular section, allowing a partial flow of water to flow into the space and form a vortex there.

[0020] Between the inlet and outlet, the electrolyte flow is divided into two substreams. A first substream flows directly to the outlet, while a portion of the salt solution or pool water swirls past the electrode stack in a second substream. Due to its design, the bypass is already integrated into a compact housing, eliminating the need for an additional bypass.

[0021] The electrolysis cell is designed in particular such that the electrolyte flows tangentially or secantially into the chamber. The plate-shaped electrodes are stacked parallel to the base of the circular-cylindrical chamber, spaced apart from one another.

[0022] Preferably, the electrodes extend from the space into the input stream. In particular, the stacked electrodes of the electrode stack extend into the tubular section that overlaps the space.

[0023] The electrolysis cell preferably has an electrode pack with a plurality of stacked electrodes, in particular 3 to 10 electrodes.

[0024] The inner electrodes of the electrode stack can be arranged as bipolar electrodes. Bipolar electrodes are not connected to the electrical terminals of the electrolysis cell. The bipolar electrodes are freely positioned and are surrounded by electrolyte. The bipolar electrodes serve as reaction carriers.

[0025] This arrangement ensures a particularly simple construction of the electrolysis cell.

[0026] For the production of chlorine or bromine for swimming pool disinfection, the electrolysis cell is preferably designed as a single-piece, i.e., undivided electrolysis cell. Instead of a bipolar arrangement of the inner electrodes of the electrode stack, in another embodiment of the invention, these are connected in parallel and / or in series.

[0027] In one embodiment of the invention, the electrodes are located in holders or frames which are stacked in the space of the housing.

[0028] The holders can, in particular, comprise fingers for receiving the plate-shaped electrodes. In particular, the holders can be ring-shaped, especially circular.

[0029] Furthermore, the holders preferably comprise spacers and can be stacked on top of one another, in particular plugged onto one another, so that the individual plate-shaped electrodes are positioned at a defined distance from one another via the holders in the housing. The spacers can be designed, for example, as webs. The electrode package with the holders can thus be permeated with water from the casing side. The holders form a type of grid through which the water can flow.

[0030] In a further development of the invention, the electrodes are polygonal. In particular, the electrodes are triangular, square, or hexagonal.

[0031] This geometry has the advantage that the electrodes are produced by separating them from a single sheet material, eliminating any waste between the individual electrodes. In particular, the hexagonal configuration closely approximates the circular-cylindrical shape of the housing. The invention further relates to an electrolytic cell, in particular an electrolytic cell with the features described above.

[0032] This comprises an inlet and an outlet, as well as a housing with a plurality of plate-shaped electrodes, wherein the housing provides a space with the electrodes. In particular, an electrode pack with a plurality of electrodes is located in the space.

[0033] An electrolyte can be introduced into the space containing the electrodes. According to the invention, the space comprises an electrolyte inlet through which the electrolyte can be introduced into a main flow through the space via the electrodes.

[0034] In this embodiment of the invention, the electrolysis cell comprises a housing through which a main stream, in particular a circulation line from a swimming pool, is passed.

[0035] The chamber is connected to the main current in such a way that electrolyte can flow from the chamber into the main current.

[0036] The housing also includes another inlet, an electrolyte inlet, through which electrolyte can be fed directly into the chamber. Using the electrolyte, free chlorine or bromine, for example, is produced in the chamber and then fed into the main stream.

[0037] This design enables a particularly simple provision of an electrolysis cell without an additional bypass.

[0038] In particular, it may be the electrolysis cell described above, which comprises an additional electrolyte inlet leading into the space containing the electrode package.

[0039] The electrolyte inlet can be used in particular to produce chlorine or bromine from an electrolyte concentrate and to introduce this into the main stream.

[0040] The concentrated electrolyte can be provided, for example, by a salt separation system through which the pool water is passed. This can, in particular, be a reverse osmosis system.

[0041] The salt separation system produces low-salt water, which is returned to the swimming pool, as well as concentrated electrolyte, which is metered into the electrolysis cell via the electrolyte inlet.

[0042] In one embodiment of the invention, it is particularly provided that an insert part is inserted in the main stream, which provides an exit for the space with the electrodes.

[0043] The insert part is preferably designed to be removable and is used when the electrolysis cell is to be connected to the electrolyte inlet.

[0044] If the pool water is used directly as the electrolyte, the insert can be omitted and the electrolyte inlet is not connected. In this case, a vortex must be created in the electrolysis cell chamber, and chlorine or bromine is generated directly from the pool water.

[0045] If, however, the electrolysis cell is used to produce chlorine or bromine from an electrolysis concentrate, for example in a salt separation plant, the insert part is used and provides the outlet of the chamber containing the electrodes.

[0046] The insert can, in particular, be designed as a lid that reduces the opening between the main flow and the space containing the electrodes. No significant amount of water now flows from the main flow into the space; instead, electrolyte concentrate is fed into the space via the electrolyte inlet, and the water enriched with free chlorine or bromine enters the main flow via the insert.

[0047] The invention further relates to a method for producing an electrolytic cell , in particular an electrolytic cell as described above .

[0048] According to the invention, a plate-shaped electrode material made of a coated metal is provided.

[0049] The electrodes may in particular be provided from coated titanium, tantalum or nickel and comprise a conductive oxide layer.

[0050] Iridium oxide and / or ruthenium oxide or platinum can serve as a conductive oxide layer.

[0051] The material of the plate-shaped electrode can, for example, have a thickness of 0.5 to 2 mm.

[0052] According to the invention, this material is divided into polygonal, particularly hexagonal, electrodes, which are then inserted into a housing of the electrolysis cell. In particular, the electrodes can be punched out, laser-cut, or water-jet cut.

[0053] The use of a hexagonal shape enables production with almost no waste.

[0054] Instead, a material such as titanium is preferably used, which oxidizes at the edges and thus forms an oxidizing protective layer. The cut edge is thus passivated.

[0055] This even has the advantage that an electrode is automatically provided which has a material with lower electrical conductivity on the edges than on the front and back.

[0056] Brief description of the drawings

[0057] The subject matter of the invention will be explained in more detail below with reference to the drawings Fig. 1 to Fig. 5 using an embodiment.

[0058] Fig. 1 is a perspective view of an electrolytic cell according to the invention.

[0059] Fig . 2 is a longitudinal section of the electrolytic cell .

[0060] Fig . 3 is a cross section of the electrolytic cell .

[0061] Referring to the sectional views of Fig. 4 and Fig. 5, the electrolysis cell is intended to be used for a concentrate, with an insert inserted into the main flow of the electrolysis cell. Detailed Description of the Drawings

[0062] Fig. 1 shows a perspective view of an embodiment of an electrolysis cell 1 according to the invention. The electrolysis cell 1 comprises a housing 10, which provides a substantially circular-cylindrical space 13, which is closed by a lid 11.

[0063] The lid 11 can in particular be designed as a screw lid.

[0064] Furthermore, the housing 10 comprises a pipe section 14 which provides an inlet 15 and an outlet 16.

[0065] By means of the pipe section 14, the electrolysis cell 1 can be installed in particular in the circulation line of a swimming pool.

[0066] The housing 10 is thus formed by a circular cylindrical space

[0067] 13 is formed, which intersects with the pipe section 14 on the shell side.

[0068] The cover 11 comprises star-shaped webs 12, which serve as stiffening webs or grips for screwing the cover 11 on and off. An electrical connector 3a for connecting an electrode protrudes from the housing 10, or more precisely, from the cover 11.

[0069] Fig . 2 is a longitudinal section approximately in the middle of the pipe section

[0070] 14 .

[0071] Plate-shaped electrodes 2 are stacked one on top of the other in the circular-cylindrical space 13. The space 13 overlaps with the pipe section 14, so that the space 13 is open laterally to the pipe section 14.

[0072] The electrolyte flowing in through inlet 15 thus partially flows into chamber 13, where a vortex forms. The flow directions are indicated by arrows.

[0073] Electrolyte, which leaves the vortex again, flows back into the main stream and leaves the electrolysis cell 1 via the outlet 16.

[0074] Also shown are the ring-shaped holders 20 which are inserted into the space 13.

[0075] In this exemplary embodiment, the holders 20 comprise fingers 21 which grasp and hold the electrodes 2 at the corners.

[0076] Furthermore, the holders 20 comprise spacers 22, which serve to maintain a defined distance between the holders 20 and thus between the electrodes 2.

[0077] The space 13 preferably has a diameter of 50 - 200 mm (inner diameter).

[0078] On the side opposite the pipe section 14, the housing 10 comprises the electrolyte inlet 17.

[0079] The electrolyte inlet 17 can in particular comprise a check valve and can be used alternatively if the electrolyte is not to be supplied via the inlet 15 but, for example, as a concentrate via the electrolyte inlet 17 (see Figs. 4 and 5).

[0080] Fig. 3 is a cross-section of the electrolytic cell. It shows the housing 10, which also has star-shaped webs 12 on the side opposite the screwed-on cover.

[0081] The electrical connections 3a, 3b extend centrally from the space 13. These are sealed within the housing 10, one of them in particular being located in the cover 11 of the housing 10.

[0082] The outer electrodes 2a and 2e are contacted via the electrical connections 3a, 3b.

[0083] The inner electrodes 2b - 2d, on the other hand, are arranged bipolarly and serve only as reaction carriers.

[0084] The electrodes 2a - 2e are inserted into the holders 20a - 20f.

[0085] The holders 20a - 20f are plugged together and thus form, together with the electrodes 2a - 2e, an electrode package in which the electrodes 2a - 2e are held together at a defined distance.

[0086] The electrode package projects into the pipe section 14 .

[0087] With reference to Fig. 4 and Fig. 5, the alternative use of the electrolysis cell 1 for processing an electrolyte concentrate will be explained in more detail.

[0088] Fig. 4 is a sectional view in which the pipe section 14 is cut open.

[0089] An insert 30 is now inserted into the pipe section 14, which insert comprises a bulge 31 into which the electrodes extend. Within the bulge 31 is an outlet 32 ​​through which the electrolyte enriched with chlorine or bromine flows into the main stream in the pipe section 14.

[0090] The insert part 30 thus serves to reduce the passage cross-section between the pipe section 14 and the space with the electrodes.

[0091] In this operating state, no significant amount of water flows from the pipe section 14 into the space with the electrodes.

[0092] Rather, as shown in the longitudinal section according to Fig. 5, the electrolyte is introduced via the electrolyte inlet 17 into the space 13 with the electrodes 2.

[0093] The electrolyte flows through the package with the electrodes 2 and the water enriched with free chlorine or bromine flows via the outlet 32 ​​into the main stream in the pipe section 14 .

[0094] As here together with the insert part 30, the electrolysis cell 1 can be used in particular when the concentrate from a salt separation plant (not shown) is to be introduced directly into the electrolysis cell via the electrolyte inlet 17.

[0095] The formation of a vortex surrounding the electrodes 2 is not necessary in this operating state, since the salt concentration is higher than in the operating state shown in Fig. 1 to Fig. 3.

[0096] The invention has made it possible to provide an electrolysis cell that has high efficiency and can be used flexibly, particularly for the production of free chlorine or bromine for swimming pool disinfection. List of reference symbols

[0097] 1 electrolysis cell

[0098] 2 electrodes

[0099] 3a, 3b electrical connection

[0100] 10 housings

[0101] 11 lids

[0102] 12 jetty

[0103] 13 Room

[0104] 14 Pipe section

[0105] 15 Entrance

[0106] 16 Exit

[0107] 17 Electrolyte inlet

[0108] 20 holders

[0109] 21 fingers

[0110] 22 spacers

[0111] 30 insert part

[0112] 31 Bulge

[0113] 32 Exit

Claims

Claims:

1. An electrolysis cell comprising an inlet and an outlet and a housing with a plurality of plate-shaped electrodes, wherein the housing provides an annular space into which electrolyte can be introduced from the inlet in such a way that a rotating flow is established.

2. Electrolysis cell according to the preceding claim, characterized in that the space is circular-cylindrical in shape.

3. Electrolysis cell according to one of the preceding claims, characterized in that the electrolysis cell is designed such that the electrolyte flows tangentially or secantially into the space.

4. Electrolysis cell according to one of the preceding claims, characterized in that the electrodes protrude from the space into an input stream.

5. Electrolysis cell according to one of the preceding claims, characterized in that the electrolysis cell comprises an electrode package with a plurality of stacked electrodes, in particular 5 to 10 electrodes.

6. Electrolysis cell according to the preceding claim, characterized in that inner electrodes of the electrode package are arranged as bipolar electrodes.

7. Electrolysis cell according to one of the preceding claims, characterized in that the electrodes are mounted in holders which are stacked in the space of the housing. Electrolysis cell according to one of the preceding claims, characterized in that the electrodes are polygonal, in particular hexagonal. Electrolysis cell, in particular according to one of the preceding claims, comprising an inlet and an outlet and a housing with a plurality of plate-shaped electrodes, wherein the housing provides a space with the electrodes, into which electrolyte can be introduced, wherein the space comprises an electrolyte inlet, via which the electrolyte can be introduced through the space via the electrodes into a main stream. . Electrolysis cell according to the preceding claim, characterized in that an insert part is placed in the main stream, which insert part provides an outlet for the space with the electrodes. .Use of an electrolysis cell according to one of the preceding claims for producing an oxidizing agent, in particular free chlorine, for swimming pool disinfection. A method for producing an electrolysis cell, in particular an electrolysis cell according to one of the preceding claims, wherein a plate-shaped electrode material made of a coated metal is provided, which is divided into polygonal, in particular hexagonal, electrodes, which are inserted into a housing of the electrolysis cell.

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