ELECTROLYZER, USE FOR AN ELECTROLYZER, FEED PIPE FOR AN ELECTROLYZER AND DISCHARGE PIPE FOR AN ELECTROLYZER

Abstract

An electrolyzer with a plurality of cell elements, and with a feed pipe and a discharge pipe for feeding and discharging electrolyte to and from the cell elements, wherein the feed pipe and/or the discharge pipe have, at least in some sections, at least two electrically isolated part-lines, wherein the part-lines extend in the feed pipe over a predetermined length in the opposite direction to the direction of electrolyte flow and/or extend in the discharge pipe over a predetermined length in the same direction as the direction of electrolyte flow.

Claims

1. An electrolyzer, comprising: a plurality of cell elements, a feed pipe, and a discharge pipe for feeding and discharging electrolyte to and from the cell elements, wherein the feed pipe and/or the discharge pipe has at least in portions at least two partial lines configured to be galvanically isolated from one another, wherein the partial lines extend in the feed pipe with a predetermined length in a direction counter to an electrolyte flow direction and/or in the discharge pipe with a predetermined length in a direction of the electrolyte flow direction.

2. The electrolyzer as claimed in claim 1, wherein the partial lines are configured as partial lines formed concentrically with one another.

3. The electrolyzer as claimed in claim 2, wherein the partial lines are respectively configured to provide an equal cross-sectional area.

4. The electrolyzer as claimed in claim 1, wherein the partial lines are formed by an insert in the feed pipe and/or the discharge pipe.

5. The electrolyzer as claimed in claim 4, wherein the insert comprises at least one pipe portion and a ring element assigned to each pipe portion, wherein the respective ring element extends radially outward from the respective pipe portion and in each case terminates a partial line.

6. An insert for use in an electrolyzer as claimed in claim 1, comprising: at least one pipe portion and a ring element assigned to each pipe portion, wherein the respective ring element extends radially outward from the respective pipe portion and in an inserted state in each case terminates a partial line.

7. A feed pipe for an electrolyzer, comprising: an insert as claimed in claim 6.

8. A discharge pipe for an electrolyzer, comprising: an insert as claimed in claim 6.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The invention will now be explained below with the aid of a drawing, in which:

[0015] FIG. 1 shows a schematic representation of component parts of an electrolyzer;

[0016] FIG. 2 shows a schematic representation of an insert for the electrolyzer shown in FIG. 1;

[0017] FIG. 3 shows a schematic representation of further details of the insert shown in FIG. 2;

[0018] FIG. 4 shows a schematic representation of a combination of the DC chopper controller shown in FIGS. 1 to 3 with a rectifier;

[0019] FIG. 5 shows a schematic representation of a further insert for the electrolyzer shown in FIG. 1.

DETAILED DESCRIPTION OF INVENTION

[0020] Reference is firstly made to FIG. 1.

[0021] An electrolyzer 2 is represented.

[0022] In the present exemplary embodiment, the electrolyzer 2 comprises a plurality of cell elements 4, which form a stack 10 and are electrically connected in series. The electrolyzer 2 in the present exemplary embodiment further comprises a feed pipe 6 and a discharge pipe 8, each with a circular cross section, with which electrolyte can first be supplied to the cell elements 4 and then discharged from the cell elements 4. For this purpose, the feed pipe 6 and the discharge pipe 8 each have a plurality of outlet and inlet openings (not represented).

[0023] In order to achieve current path lengthening of the current paths of electrical stray currents, in the present exemplary embodiment an insert 14 is respectively inserted in the feed pipe 6 and in the discharge pipe 8.

[0024] The structure of an exemplary embodiment of the insert 14 will now be explained with additional reference to FIGS. 2 and 3.

[0025] In the present exemplary embodiment, the insert 14 comprises a pipe portion 16a with a circular cross section and a ring element 18a assigned to the pipe portion 16a. The ring element 18a in the present exemplary embodiment extends radially outward from the pipe portion 16a.

[0026] The insert 14 in the present exemplary embodiment is configured in one piece and/or materially uniformly. In particular, in the present exemplary embodiment the insert 14as well as the feed pipe 6 and the discharge pipe 8are made from an electrically insulating material. Reference is now additionally made to FIG. 4.

[0027] This figure represents that, in the state inserted in the feed pipe 6 or discharge pipe 8, the respective ring element 18a comes in contact with the inner wall of the feed pipe 6 or of the discharge pipe 8 and thus provides a termination, which in the present exemplary embodiment closes an outer partial line 12a of two partial lines 12a, 12b, it being additionally possible in this case to provide gaskets for sealing.

[0028] The feed pipe 6 and the discharge pipe 8 in the present exemplary embodiment are configured to be stiff in the portion in which the respective inserts 14 are located and flexible in comparison thereto in the remaining portion.

[0029] In the present exemplary embodiment, the outer partial line 12a of the two partial lines 12a, 12b is configured to have a concentric annular cross section. Conversely, in the present exemplary embodiment the inner partial line 12a has a circular cross section. In the present exemplary embodiment, the two cross-sectional areas are equal in size, i.e. the annular cross-sectional area of the outer partial line 12a is equal to the circular cross-sectional area of the inner partial line 12b. Supporting elements (not represented) may be provided in order to support the two partial lines 12a, 12b.

[0030] For example, a front half of the stack 10 with a total of for example 100 cell elements, that is to say cell elements 1 to 50, thus receives and is supplied with electrolyte through the outer partial line 12a, while the rear half of the stack 10, that is to say cell elements 51 to 100, is supplied with electrolyte through the inner partial line 12b.

[0031] Furthermore, in the present exemplary embodiment the inserts 14 respectively inserted into the feed pipe 6 and the discharge pipe 8 extend in the case of the feed pipe 6 with a predetermined length L in the direction counter to the electrolyte flow direction E, and in the case of the discharge pipe 8 with the predetermined length L in the direction of the electrolyte flow direction E. In the present exemplary embodiment, the respective lengths L are equal in size. As an alternative to the present exemplary embodiment, they may however also differ in size.

[0032] In the present exemplary embodiment, the length L has a value in the range of from 0.5 m to 3 m, for example 2 m.

[0033] The insertion of the insert 14 separates the front half of the stack 10 from the rear half. Electrical stray currents that come from the rear half and enter the front half are thereby forced onto lengthened current paths S. The lengthened current paths S are associated with an increased ohmic resistance, so that the electrical stray current strengths are reduced. A maximum of the electrical stray current density may thus be reduced to 71%.

[0034] A further exemplary embodiment of the insert 14 will now be explained with additional reference to FIG. 5.

[0035] The present exemplary embodiment according to FIG. 5 differs from the previous exemplary embodiment in that four pipe portions 16a, 16b, 16c, 16d are provided, each of the four pipe portions 16a, 16b, 16c, 16d respectively comprising a ring element 18a, 18b, 18c, 18d.

[0036] The insert 14 according to FIG. 5 therefore forms five partial lines 12a, 12b, 12c, 12d, 12e, of which the innermost partial line 12a has a circular cross-sectional area and the remaining partial lines 12b, 12c, 12d, 12e each have an annular cross-sectional area. In the present exemplary embodiment, the circular cross-sectional area and the respective annular cross-sectional areas are each equal in size and arranged concentrically around the axis of the pipe portions 16a, 16b, 16c, 16d.

[0037] The equal areas ensure that each cell element group, in this case five cell element groups, can be supplied with the same amount of electrolyte per unit time.

[0038] With a value of 1 m for the length L, a maximum of the electrical stray current density may thus be reduced to 52%, and with a value of 2 m for the length L a maximum of the electrical stray current density may be reduced to 46%.

[0039] As an alternative to the present exemplary embodiments with circular cross-sectional areas and annular cross-sectional areas, other cross-sectional shapes may also be formed, for example rectangular or square or frame-shaped cross-sectional shapes. By the design setting of area equality through the flow elements involved, for example the partial lines 12a, 12b, 12c, 12d and 12e involved, a uniform supply of the cell element groups with the same amount of electrolyte per unit time is achieved in a particularly straightforward and reliable way.

[0040] In electrical terms, this achieves particularly effective current path lengthening for at least a part of the electrical stray currents, which entails a higher ohmic resistance due to the lengthening without design lengthening of the feed pipe 6 and/or discharge pipe 8 taking place, which would in turn entail increased flow losses of the fluids involved, in particular the electrolyte.