LIGHTNING-PROTECTION SPARK GAP

Abstract

The present invention relates to a lightning-protection spark gap, comprising: a housing (G); a first electrode (3a), which has a first outer face (Aa) and a first inner face (Ia); and a second electrode (3b), which has a second outer face (Ab) and a second inner face (Ib); wherein the first electrode (3a) and the second electrode (3b) diverge from each other; wherein a striking region (Z) and an adjoining propagation region (L) for a spark are formed between the first inner face (Ia) of the first diverging electrode (3a) and the second inner face (Ib) of the second diverging electrode (3b); wherein the housing (G) forms an arc chamber (LK) between the first electrode (3a) and the second electrode (3b), which arc chamber is delimited by a quenching chamber (4); and wherein, in the housing (G), at least one first gas circulation channel (K1) is formed, by means of which a gas flow escaping from the quenching chamber (40) in the event of a lightning strike can be returned to the arc chamber (K) via at least one first cutout (V1; V1; V1; V1) in the propagation region (L) of the first electrode (3a). The first cutout (V1; V1; V1; V1) is asymmetrical with respect to a longitudinal extent of the first cutout (V1; V1; V1; V1) in the propagation direction of the arc; the first cutout (V1; V1; V1; V1) falls in the propagation direction of the arc from a first cross-section (Q1) of the first electrode (3a) to a minimum cross-section (QM) of the first electrode (3a) over a first distance (l1; l1; l1; l1) and rises from the minimum cross-section (QM) of the first electrode (3a) to a second cross-section (Q2) of the first electrode (3a) over a second distance (l2; l2; l2; l2). The first distance (l1; l1; l1; l1) is shorter than the second distance (l2; l2; l2; l2).

Claims

1. A lightning-protection spark gap, comprising: a housing (G); a first electrode (3a), having a first outer side (Aa) and a first inner side (Ia), and a second electrode (3b), having a second outer side (Ab) and a second inner side (Ib), wherein the first electrode (3a) and the second electrode (3b) diverge from each other; wherein, between the first inner side (Ia) of the first diverging electrode (3a) and the second inner side (Ib) of the second diverging electrode (3b), an ignition region (Z) and a subsequent propagation region (L) for an arc are formed; wherein the housing (G) forms an arc chamber (LK), which is arranged between the first and second electrodes (3a, 3b) and which is delimited by a quenching chamber (4); and wherein, in the housing (G), at least one gas circulation channel (K1) is configured, by means of which a gas flow escaping from the quenching chamber (40) in the event of a lightning stroke can be returned to the arc chamber (LK) via at least one first cut-out (V1; V1; V1; V1) in the propagation region (L) of the first electrode (3a); characterized in that the first cut-out (V1; V1; V1; V1) is configured asymmetrically with respect to a longitudinal extension of the first cut-out (V1; V1; V1; V1) in the propagation direction of the arc; and the first cut-out (V1; V1; V1; V1), in the propagation direction of the arc, decreases from a first cross-section (Q1) of the first electrode (3a) to a minimum cross-section (QM) of the first electrode (3a) over a first distance (l1; l1; l1; l1), and increases from the minimum cross-section (QM) of the first electrode (3a) to a second cross-section (Q2) of the first electrode (3a) over a second distance (l2; L2; l2; l2); and the first distance (l1; l1; l1; l1) is shorter than the second distance (l2; l2; l2; l2).

2. The lightning-protection spark gap as claimed in claim 1, wherein the first electrode (3a) comprises two first cut-outs (V1; V1; V1; V1), which are arranged in symmetrical opposition.

3. The lightning-protection spark gap as claimed in claim 1 wherein, in the housing (G), at least one second gas circulation channel (K2) is configured, by means of which a gas flow escaping from the quenching chamber (40) in the event of a lightning stroke can be returned to the arc chamber (LK) via at least one second cut-out (V2; V2; V2; V2) in the propagation region (L) of the second electrode (3b); the second cut-out (V2; V2; V2; V2) is configured asymmetrically with respect to a longitudinal extension of the second cut-out (V2; V2; V2; V2) in the propagation direction of the arc; and the second cut-out (V2; V2; V2; V2), in the propagation direction of the arc, decreases from a first cross-section (Q1) of the second electrode (3b) to a minimum cross-section (QM) of the second electrode (3b) over the first distance (l1; l1; l1; l1), and increases from the minimum cross-section (QM) of the second electrode (3b) to a second cross-section (Q2) of the first electrode (3a) over a second distance (l2; L2; l2; l2); and the first distance (l1; l1; l1; l1) is shorter than the second distance (l2; L2; l2; l2).

4. The lightning-protection spark gap as claimed in claim 3, wherein the second electrode (3b) comprises two second cut-outs (V2; V2; V2; V2), which are arranged in symmetrical opposition.

5. The lightning-protection spark gap as claimed in claim 1, wherein the first cross-section (Q1) and the second cross-section (Q2) are equal.

6. The lightning-protection spark gap as claimed in claim 1, wherein the second distance (l2; L2; l2; l2) is at least double the length of the first distance (l1; l1; l1; l1).

7. The lightning-protection spark gap as claimed in claim 1, wherein the first distance (l1; l1; l1; l1) is zero.

8. The lightning-protection spark gap as claimed in claim 1, wherein the first distance (l1; l1; l1; l1) and/or the second distance (l2; L2; l2; l2) extend over at least one curved section (R1).

9. The lightning-protection spark gap as claimed in claim 1, wherein the first distance (l1; l1; l1; l1) and/or the second distance (l2; L2; l2; l2) extend over at least one linear section (L1; L1, L2; L1, L2; L1, L2).

10. The lightning-protection spark gap as claimed in claim 1, wherein the quenching chamber (4) comprises a plurality of parallel-oriented arc splitter plates (40), to which gas outlet channels (45) connect, which terminate in the first or second gas circulation channel (K1; K2).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In the drawings:

[0038] FIGS. 1a)-d) show schematic views for the illustration of a lightning-protection spark gap according to a first embodiment of the present invention, wherein FIG. 1a) is a perspective representation, FIG. 1b) is a sectional enlargement of the first electrode, FIG. 1c) is a plane overhead view of the inner side of the first electrode, and FIG. 1d) is a sectional enlargement of the outline of a cut-out in the first electrode;

[0039] FIGS. 2a), b) show schematic views for the illustration of a lightning-protection spark gap according to a second embodiment of the present invention, wherein FIG. 2a) is a plane overhead view of the inner side of the first electrode, and FIG. 2b) is a sectional enlargement of the outline of a cut-out in the first electrode;

[0040] FIGS. 3a), b) show schematic views for the illustration of a lightning-protection spark gap according to a third embodiment of the present invention, wherein FIG. 3a) is a plane overhead view of the inner side of the first electrode, and FIG. 3b) is a sectional enlargement of the outline of a cut-out in the first electrode;

[0041] FIGS. 4a), b) show schematic views for the illustration of a lightning-protection spark gap according to a fourth embodiment of the present invention, wherein FIG. 4a) is a plane overhead view of the inner side of the first electrode, and FIG. 4b) is a sectional enlargement of the outline of a cut-out in the first electrode; and

[0042] FIGS. 5a)-d) show schematic views for the illustration of a lightning-protection spark gap which is known from DE 10 2005 015 401 B4.

[0043] In the figures, identical or functionally equivalent elements are identified by the same reference symbols.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0044] FIGS. 1a)-d) show schematic views for the illustration of a lightning-protection spark gap according to a first embodiment of the present invention, wherein FIG. 1a) is a perspective representation, FIG. 1b) is a sectional enlargement of the first electrode, FIG. 1c) is a plane overhead view of the inner side of the first electrode, and FIG. 1d) is a sectional enlargement of the outline of a cut-out in the first electrode.

[0045] The lightning-protection spark gap according to the first embodiment comprises a first electrode 3a, having a first outer side Aa and a first inner side Ia. The lightning-protection spark gap further comprises a second electrode 3b, having a second outer side Ab and a second inner side Ib. The first and second electrodes 3a, 3b are arranged in a housing G, the trough-shaped underside of which is represented. The housing cover is not represented.

[0046] The first and second electrodes 3a, 3b are formed of a conductive material. In the present example, the material is special steel or copper, or an alloy thereof. The first and second electrodes 3a, 3b diverge from each other.

[0047] Between the first inner side 1a of the first electrode 3a and the second inner side of the second electrode 3b, an ignition region Z and a subsequent propagation region L for an arc are formed. In the ignition region Z, the first electrode 3a and the second electrode 3b are closely spaced, whereas the clearance therebetween expands continuously in the propagation region L. Where the (unrepresented) housing cover is fitted, an arc chamber LK is formed between the first and second electrodes 3a, 3b.

[0048] At the end of the propagation region L, a quenching chamber 4 is located in the arc chamber LK, comprising a plurality of parallel-oriented arc splitter plates 40, on which gas outlet channels 45 are located. The quenching chamber is laterally enclosed by the end regions 5a, 5b of the first and second electrodes 3a, 3b.

[0049] Between the housing G and the outer side Aa of the first electrode 3a, a first gas circulation channel K1 is formed and, between the housing G and the outer side Ab of the second electrode 3b, a second gas circulation channel K2 is formed.

[0050] The first electrode 3a is connected to a first electric terminal contact 1a via a connecting region 6a, and the second electrode 3a is connected to a second electric terminal contact 1b via a connecting region 6b. The first and second electric terminal contacts 1a, 1b are led out through the wall of the housing, such that an electrical connection to an electric power grid which is to be protected against lightning stroke can be formed. The first and second electrodes 3a, 3b comprise pins Za, Zb, by means of which the latter engage in corresponding fixing holes in the housing G.

[0051] On the outer side Aa of the first electrode, additionally, a ferromagnetic concentrator F1 is provided opposite the propagation region L.

[0052] In the propagation region L, at the end of the ignition region Z, the first electrode 3a comprises symmetrically opposing first cut-outs V1 and, in the propagation region L, at the end of the ignition region Z, the second electrode 3a comprises symmetrically opposing second cut-outs V2. The first cut-outs V1 form a fluidic connection between the first gas circulation channel K1 and the arc chamber LK, and the second cut-outs V2 form a fluidic connection between the second gas circulation channel K2 and the arc chamber LK.

[0053] In the event of lightning stroke, in a first phase, lightning energy is essentially converted into a pulse current in the ignition region Z whereas, in a second phase, in the propagation region L, a secondary arc which is driven by a secondary current is propagated in the direction of the arc quenching chamber 4.

[0054] The gas flow produced by the generation of an arc is conducted via the gas outlet channels 45 into the first and second gas circulation channels K1, K2 and, via the first and second cut-outs V1, V2 is at least partially fed back to the arc chamber LK, in order to support the motion of the arc.

[0055] The specific configuration of first and second cut-outs V1, V2 arranged in opposition on either side of the first or second electrodes 3a, 3b, as particularly represented in FIGS. 1c) and 1d), supports the propagation behavior of the arc in the region of the cut-outs V1, V2, and can effectively prevent any retention or suspension of the arc in the region of the cut-outs V1, V2.

[0056] The cut-outs V1, V2, represented here by the cut-out V1, in the first embodiment, extend asymmetrically with respect to the longitudinal extension of the cut-outs V1, V2 in the propagation direction of the arc. In particular, the cross-section of the first electrode 3a tapers from a first cross-section Q1 to a minimum cross-section QM, in the form of a curved section R1, and then, in a linear section L1, increases continuously up to a cross-section Q2, which corresponds here to a cross-section Q1.

[0057] A distance l1 of the curved section R1 is substantially shorter than a distance l2 of the linear section L1.

[0058] FIGS. 2a), b) show schematic views for the illustration of a lightning-protection spark gap according to a second embodiment of the present invention, wherein FIG. 2a) is a plane overhead view of the inner side of the first electrode and FIG. 2b) is a sectional enlargement of the outline of a cut-out in the first electrode.

[0059] The specific configuration of the first and second cut-outs V1, V2 arranged in opposition on either side of the first or second electrodes 3a, 3b, as particularly represented in FIGS. 2a) and 2b), also supports the propagation behavior of the arc in the region of the cut-outs V1, V2, and can effectively prevent any retention or suspension of the arc in the region of the cut-outs V1, V2.

[0060] The cut-outs V1, V2, represented here by the cut-out V1, in the second embodiment, also extend asymmetrically with respect to the longitudinal extension of the cut-outs V1, V2 in the propagation direction of the arc. In particular, the cross-section of the first electrode 3a tapers from a first cross-section Q1 to a minimum cross-section QM, in the form of a first linear section L1, and then, in a second linear section L2, increases continuously up to a cross-section Q2, which corresponds here to the cross-section Q1.

[0061] A distance l1 of the first linear section L1 is substantially shorter than a distance l2 of the second linear section L2.

[0062] Otherwise, the second embodiment is configured in the manner of the above-mentioned first embodiment.

[0063] FIGS. 3a), b) show schematic views for the illustration of a lightning-protection spark gap according to a third embodiment of the present invention, wherein FIG. 3a) is a plane overhead view of the inner side of the first electrode, and FIG. 3b) is a sectional enlargement of the outline of a cut-out in the first electrode.

[0064] The specific configuration of the first and second cut-outs V1, V2, arranged in opposition on either side of the first or second electrodes 3a, 3b, as particularly represented in FIGS. 3a) and 3b), in an analogous manner, supports the propagation behavior of the arc in the region of the cut-outs V1, V2, and can effectively prevent any retention or suspension of the arc in the region of the cut-outs V1, V2.

[0065] The cut-outs V1, V2, represented here by the cut-out V1, in the third embodiment, extend asymmetrically with respect to the longitudinal extension of the cut-outs V1, V2 in the propagation direction of the arc. In particular, the cross-section of the first electrode 3a tapers from a first cross-section Q1 to a minimum cross-section QM, in the form of a rectangular stage L1, and then increases continuously in a linear section L2 over a distance l2 up to a cross-section Q2, which corresponds here to the cross-section Q1. In this embodiment, the first distance l1 is practically zero.

[0066] Otherwise, the third embodiment is configured in the manner of the above-mentioned first embodiment.

[0067] FIGS. 4a), b) show schematic views for the illustration of a lightning-protection spark gap according to a fourth embodiment of the present invention, wherein FIG. 4a) is a plane overhead view of the inner side of the first electrode, and FIG. 4b) is a sectional enlargement of the outline of a cut-out in the first electrode.

[0068] The specific configuration of the first and second cut-outs V1, V2, arranged in opposition on either side of the first or second electrodes 3a, 3b, as particularly represented in FIGS. 4a) and 4b), supports the propagation behavior of the arc in the region of the cut-outs V1, V2, and can also effectively prevent any retention or suspension of the arc in the region of the cut-outs V1, V2.

[0069] The cut-outs V1, V2, represented here by the cut-out V1, in the fourth embodiment, extend asymmetrically with respect to the longitudinal extension of the cut-outs V1, V2 in the propagation direction of the arc. In particular, the cross-section of the first electrode 3a tapers from a first cross-section Q1 to a minimum cross-section QM, in the form of a first linear section L1, and then increases continuously in a second linear section L2 up to a cross-section Q2, which corresponds here to the cross-section Q1.

[0070] A distance l1 of the first linear section L1 is substantially shorter than a distance l2 of the second linear section L1.

[0071] In comparison with the above-mentioned embodiments, in the fourth embodiment, the configuration of the overall distance l1+l2 of the cut-outs V1, V3 is shorter.

[0072] Otherwise, the fourth embodiment is configured in the manner of the above-mentioned first embodiment.

[0073] Although the invention has been fully described above with reference to preferred exemplary embodiments, it is not limited thereto, but is modifiable in a variety of ways.

[0074] In particular, the present invention is not limited to the specific cut-out geometries represented. Likewise, the invention is not limited to the electrode geometries illustrated but, in principle, is applicable to any arbitrary electrode geometries.

[0075] Although, in the embodiments described, asymmetrical cut-outs are provided on both electrodes in mirror symmetry in each case, the invention is not limited thereto, and an asymmetrical cut-out can be provided on only one side, on one or both electrodes, or on both sides of only one of the two electrodes.