JP4745389B2 - Capsule, pressure resistant, non-hermetic, rotationally symmetric high performance spark gap - Google Patents

Abstract

The invention relates to an encapsulated, flameproof, not hermetically sealed, rotationally symmetrical high-performance spark gap with two main electrodes spaced apart opposite each other, a metal outer housing, at least one trigger electrode, a gas or plasma cooling space, surrounded by the outer housing, and external electrical contacts for the main electrodes, preferably arranged on the end face. According to the invention, the cooling space comprises a coaxial arrangement of an inner cup and an outer cup, one of the main electrodes being formed as a hollow-cylindrical expulsion electrode and reaching into the inner cup. Also provided on the open side of the cup arrangement is a supporting ring, engaging laterally around the expulsion electrode. The supporting ring is connected to the outer cup in a flameproof manner, in particular with nonpositive and/or positive engagement. The outer cup of the coaxial arrangement has lateral gas outlet openings. Provided between the inner and outer cups there is at least one gas cooling duct. Between the outer wall of the outer cup and the inner wall of the outer housing there is a further, gap-like gas cooling duct. The gas cooling ducts themselves follow an altogether meandering path.

Description

  The present invention relates to two main electrodes that are spaced apart from each other and face each other, a metal outer housing, at least one trigger electrode, and an outer housing according to claim 1 Relates to a capsule-type, pressure-resistant, non-hermetic, rotationally symmetric, high-performance spark gap having a gas or plasma cooling space surrounded by and an electrical connection contact for the main electrode, which is preferably arranged in front.

  Prior art spark gap-based lightning arresters, when used in low voltage applications, are realized in an encapsulated fashion to avoid blowing out hot gases that are harmful to the environment or still ionized Has been.

  In prior art blow-off lightning arresters, the largest part of the energy conversion up to about 90% is in the form of hot gas to the environment. In modern spark gaps, it is clear that avoiding blow-off increases both thermal and dynamic loads. In an encapsulated lightning arrester, these increased loads prevent the necessary control over pulse and continuity from being made as small as possible.

  In order to achieve a lower protection level in the lower kV range, an additional trigger mechanism is provided in the arrester. In one such trigger mechanism, it is necessary to insulate additional additional electrodes to which generally high voltages are applied. The increase in structural size and the additional insulating material will further limit the efficiency of the arrester realized in this manner.

  According to DE 100 08 764 A1 and the capsule-type spark gap shown therein, it is known to supply a trigger potential via a metal housing cover of the spark gap. The main electrodes provided here are insulated from each other and inserted into a spark gap facing the housing. However, because of the short arc length and the simple arc placement, there are only a few wake limitations achieved by this prior art solution.

  In the capsule type lightning arrester according to DE 100 18 012 A1, the potential of the ignition electrode is also supplied by a pressure-resistant metal cover of the spark gap. Here, the pressure-resistant cover is manufactured as a single component, and a simple molding process is used for manufacturing. In this modification, the ignition potential is realized without insulation, so the two electrodes must be insulated from each other and from the entire housing. This has led to increased costs. In addition to the need for more space, complex and surge resistant insulation, especially the heat output from the spark gap, is also hindered. This leads to an increase in the thermal load applied to the insulating member, resulting in a longer cooling time and greatly restricting the space available for the spark gap. All of these disadvantages ultimately limit the efficiency of the spark gap.

  Thus, when further release of hard gas results to improve certain parameters of the spark gap, both thermal and mechanical pressure loads are further increased in both pulse and wake. A large energy conversion will lead to an increase.

  DE 101 64 025 A1 discloses a capsule triggerable spark gap which operates according to the principle of Radax-Flow. This prior art solution uses a spark gap cubic housing for cooling hot gases. Supply to the trigger electrode is performed through an insulating member of the second main electrode insulated from the housing. Due to the geometrical implementation of the housing, this type of variation is very complex and substantially limits the space for arc activity compared to the space for gas cooling.

  The prior art solution that has been briefly identified above is a low voltage spark air gap capable of carrying surge currents, which has a high resistance to pressure due to their structural design. Includes air gap.

  EP 0 305 077 A1 presents a lower response spark gap in which the trigger electrode protrudes through the outer housing of the spark gap made of an insulating material. This spark gap cannot carry surge currents, exhibits a smaller main electrode gap, and has no means for increasing the arc voltage. In this prior art spark gap, the conversion of power and thus the associated thermal and mechanical loads are inadequate. This type of spark gap is not suitable for use in low voltage networks. Here, the dynamic load capacity of the housing and the performance of the trigger electrode are likewise low.

  From the above, the subject of the present invention is a further development of a capsule-type, pressure-resistant, non-hermetic, rotationally symmetric high-performance spark gap that is separated from each other and opposed to each other, and a metal A spark gap having an outer housing, at least one trigger electrode, a gas or plasma cooling space surrounded by the outer housing, and an electrical connection contact for the main electrode, preferably disposed in front Thus, the spark gap provides a carrying capacity for surge voltage loads which is almost twice as large as the currently known spark gaps, nevertheless with a simple and technically manageable configuration. And identifying a spark gap that provides good and rapid cooling of the hot gas.

  The solution to the problem of the invention is provided by a spark gap with a combination of the features of claim 1, and the dependent claims constitute functional embodiments and further improvements to the same or greater extent. .

  The most basic components of the high performance spark gap presented herein are the realization of the pressure resistance of the active components in the spark gap and the pressure resistance and encapsulation of the gap and cooling space in the outer housing. In an embodiment, a cooling channel is provided for effective cooling of hot gas having a stepped exhaust opening and a serpentine configuration. A further advancement is that the trigger potential is isolated and introduced from the radial direction.

  The cooling space of the high performance spark gap according to the present invention is composed of a coaxial assembly consisting of metal inner and outer cups, one of the main electrodes being configured as a hollow cylindrical blow-off electrode, most of which It extends into the inner cup of the coaxial assembly.

  A support ring surrounding the blow-off electrode from the side is provided on the open side of the cup assembly. The support ring is for pressure resistance and is preferably fitted to the outer cup by force and / or fitted by outer shape, for example connected by a corresponding screw pair.

  The outer cup of the coaxial assembly is provided with a lateral hole as a gas outlet opening. At least one gas cooling channel is provided between the inner and outer cups of the coaxial assembly. A further gas cooling channel is located between the outer wall of the outer cup and the inner wall of the outer housing. This gas cooling channel is gap-shaped, i.e. has a smaller dimension than the first gas cooling channel.

  In accordance with the above-described objectives of the present invention, this high performance spark gap allows for higher pulse loads and stronger current limiting, resulting in more energy being converted in the spark gap and heating. A larger amount of gas or plasma is produced.

Therefore, it is necessary to realize a more powerful cooling and expansion of the gas. This is brought about by the coaxial assembly described above, ie a gas with a longer path and a stronger contact or a stronger contact to the cooling material. This cooling material has a large heat capacity, good heat conduction, and a high melting point.

  In addition to more powerful cooling, the spark gap presented herein performs the control of increasing burnout without the exhaust channels provided as described above being completely closed by the combustion particles.

  In a preferred embodiment of the invention, the serpentine cooling channel gradually transitions from a relatively large diffusion cross-section to a narrower cross-section. This has the effect that the cooling channel cannot be completely blocked by the molten material. In a further series of cooling channel (s), there is intentionally provided a region where the already solidified material can be deposited without problems for evacuation.

  The exhaust openings arranged in a stepwise manner in the cooling channel initially exhibit a small cross-section to prevent the emission of illumination gas and molten particulates, increasing the cross-section only in the continuation of further stretching of the cooling channel, and thus the flow and Expansion can be used throughout the cooling area. These means compensate for clogging of the individual exhaust openings in the first part of the cooling channel.

  In a further embodiment, a blow-off electrode according to the present invention has an annular flange disposed on its upper side facing the counter electrode, and a support ring having a pair of steps adjacent to the flange. positioned. The lower side of the blow-off electrode is closed while presenting a lateral gas outlet opening and is provided with a guide extension directed in the longitudinal direction of the electrode, the guide extension being complementary to the inner cup. Engage in the recess.

  At least one gas cooling channel, as already mentioned, is located below the blow-off electrode between the inner cup and the guide extension extending into the screw hole in the inner cup (forming the connection contact). Located in the area.

  Each cup of the coaxial assembly includes a circular ring connection piece, and the circular ring connection piece of the inner cup is attached to the circular ring connection piece of the outer cup.

  The outer housing is configured adjacent to the area of the circular ring connection piece of the outer cup, in a coherent form by outer shape, i.e., for example by a flanged step.

  In view of the configuration already described, the pressure-resistant connection of the coaxial assembly including the support ring and the blow-off electrode is realized by closing by force and / or profile, in particular by screw connection.

  For example, a sleeve or disk made of a gas releasing material such as POM is disposed between the main electrodes, and a support ring at least partially surrounds the sleeve or disk made of the gas releasing material at the outer periphery. .

  The gas releasing material has a function of blowing off the arc in the radial direction. This is used to limit the wake by arc cooling and stretching. The solution using the above-described support ring ensures control of the result of high pulse currents. Thus, the support ring can be configured to be conductive or can be configured to be insulative. It is important that the components of the spark gap are stabilized internally as a result of the uniform distribution of the load on the one hand and the improvement of the mechanical properties on the other hand.

  In the prior art solution, the pressure developed in the hot gas expansion region inside the spark gap acts directly on the region of the active gas release component. This occurs on the one hand directly by the gas that can penetrate the gaps in the stacked members and on the other hand indirectly by the mutual mobility of the individual members of the spark gap. Such a movement is particularly dangerous if the gas release is not uniform and occurs on all sides of the expansion region, but it does cause a non-uniform pressure load and therefore a lack of individual parts. And may cause damage.

  A pressure resistant cooling space is created by the typical screw connection of the present invention with the main electrode below the member in the expansion region. This solution results in a uniform distribution of pressure / force effects on the active outgassing component, and the direct flow of the respective gas between the cooling space and the active component and between the arc chamber and the cooling space. The flow is avoided.

  A trigger insulation sleeve is disposed on the side of the sleeve or disk made of gas release material away from the blow-off electrode, followed by a trigger disk made of conductive material. This trigger disk made of a conductive material is surrounded radially by a contact ring and a contact sleeve, respectively.

  A bead-shaped insulator is positioned above the trigger disk with the contact ring to ensure electrical insulation of the trigger means relative to the outer housing and main electrode of the spark gap.

  The contact ring of the triggering means can be exposed by selective radial perforation of the outer housing and penetration of the insulator behind the outer housing to make an electrical connection. The inner perforated side of the trigger disk made of a conductive material extends into the arc space and into the arc space, respectively, ensuring a reliable spark gap ignition.

  The other main electrode facing the blow-off electrode is preferably configured as a full volume disk with a guiding extension. The extending portion for guiding presents a screw hole for a connection contact.

  For example, a journal part made of a material having a particularly burnout resistance such as copper tungsten is located at the center of the disk of the other main electrode. This journal part can be connected to the disk of the other main electrode, for example, by soldering. The arrangement of the insulator with the main electrode in the form of a disk with a guiding extension is selected so that the through-hole of the insulator matches the outer diameter of the journal so that burnout occurs only in the area of the journal Is done.

  In a preferred variant, a further bead-shaped insulator is arranged on the guiding extension of the main electrode as a disk with a guiding extension, which further extends the disk of the main electrode from the side. Surrounding.

  A seal, in particular a seal ring, is arranged between the disk of the main electrode and the insulator.

  The high-performance spark gap according to the invention having a rotationally symmetric configuration is built on the basis of a coaxial assembly of cups with a blow-off electrode and a screw-in support ring, essentially in the form of a laminate, initially with a flange on one side only A hollow outer cylindrical housing houses the laminated assembly. Flanging the stationary open side results in pressing and mechanical contact of the individual pre-installed components of the spark gap laminate assembly, resulting in extremely high mechanical stability and associated electrostatics overall. Capacity is obtained.

  An introduction where the feed to the trigger electrode is insulated creates more available space for the area for cooling of the hot gas. The situation with respect to burnout impurities is also improved and the certainty of ignition is maintained even in the light of minor damage or necessary contamination of the insulation. However, it should be noted at this point that the supply of trigger voltage from the radial direction is canceled and a direct so-called cover trigger may still be used or applied here.

  Hereinafter, in order to specify the present invention in more detail, embodiments and drawings are referred to.

  A structure consisting of active and passive components of the spark gap according to FIG. 1 is located inside the outer housing 1.

  First, an inner cup 14 is provided to form a pressure-resistant cooling space, and the inner cup 14 is surrounded by an outer cup 15 separated to receive the gas cooling channel 17.

  One main electrode realized as a hollow cylindrical blow-off electrode 3 extends into the internal space of the cup 14.

  A support ring 12 surrounding the blow-off electrode 3 from the side is provided on the open side of the cup assembly. The support ring 12 presents an external thread that matches the internal thread of the outer cup 15 (see FIG. 2).

  A lateral gas outlet opening 16 is provided in the outer cup 15 so that at least the gas cooling channel 17 described above is configured between the inner and outer cups 14, 15 and is a gap-like but further gas cooling. A channel 18 is defined between the outer wall of the outer cup 15 and the inner wall of the outer housing 1.

  The blow-off electrode 3 has an annular flange 13 on the upper side facing the counter electrode 2, and a support ring 12 having a complementary step is located adjacent to the annular flange 13.

  The lower side of the blow-off electrode 3 presents a lateral gas outlet opening 19 but has a closed shape.

  Further, the lower side of the blow-off electrode 3 is provided with a guide extending portion 20 and is engaged with the recess 21 of the paired inner cup 14.

  Next, at least one gas cooling channel 22 is provided in the region of the lower surface of the blow-off electrode 3 between the inner cup and the guide extension 20 extending to the screw hole 23 of the inner cup 14. The screw hole 23 constitutes one element of the connection contact 24 such as a screw contact.

  Each of the above-described cups 14, 15 of the coaxial assembly comprises a circular ring connection piece 25, 26, so that the circular ring connection piece 25 of the inner cup 14 is connected to the circular ring connection piece 26 of the outer cup 15 of the same diameter. It is attached and fits in the region of the circular ring connection piece 26 of the outer cup 15 of the outer housing 1 by its outer shape. Here, positive fitting is achieved by flange processing in the press molding process.

  From the longitudinal cross section of FIG. 1, the cross section of the gas cooling channel is reduced from the inside to the outside, and as a result, the deposits at the first part of the channel arrangement related to flow and cooling action are harmless, it is obvious. Since there are multiple pressure compensation connections to the external environment, it does not matter if one of the associated openings becomes clogged. Such an opening to the outside environment can be configured in the region of the flange or realized by a channel 22 of the guide extension 20 through a screw hole 23 in which a pair of threaded threads are arranged can do.

  For example, a sleeve or disk 4 made of an outgassing material such as POM is arranged between the main electrodes 2 and 3 so that radial blow-off is limited in the case of ignition.

  Here, the support ring 12 at least partially surrounds the sleeve or disk 4 made of the gas releasing material at the outer periphery, stabilizing the sleeve or disk 4.

  A trigger insulating disk 5 is arranged on the surface of the sleeve or disk 4 remote from the blow-off electrode 3 made of an outgassing material. This trigger insulating sleeve 5 presenting a stepped cross section is followed by a trigger disk 6 made of a conductive material. The trigger disk 6 in the form of a circular ring is surrounded in the radial direction by a contact ring 7 made of a conductive material.

  Above the trigger ring 6 with the contact ring 7 is located a further bead-shaped insulator 8 which ensures electrical insulation of the trigger means 6 and 7 from the outer housing 1 and the main electrode 2. .

  A further main electrode 2 facing the blow-off electrode 3 is configured in the form of a disk 27 with a guiding extension 28.

  The guide extending portion 28 has a screw hole 29 for connecting a contact.

  A journal part 9 made of a material particularly resistant to burning, such as copper tungsten, is located in the center of the disk 27.

  An insulator 11, which is also in the form of a bead, is arranged on a further guide extension 28 of the main electrode 2, which surrounds the disk 27 of the main electrode 2 from the side according to the embodiment according to FIG. It is out.

  A seal is arranged between the disc-shaped main electrode 2 and the insulator 11, in particular in the form of a seal ring. Unlike the continuous screw hole 23 of the inner cup 14, the screw hole 29 is realized as a blind hole so that airtightness only occurs here.

  For electrical contact of the trigger disk 6, it is possible to make a selective radial spot drilling in the outer housing 1, ie through the insulator 8 behind the outer housing 1, the contact ring 7 Partial exposure is possible.

  For example, at a discharge gap length of about 40 mm as measured from the flanged outer edge of the housing 1, the hole diameter will be about 5-6 mm for a 140 ° drill bit. As a result, the overall discharge gap stability or breakdown voltage is not compromised.

  The high performance spark gap described above can double the surge current load capacity from approximately 25 kA to 50 kA while maintaining high ignition reliability and optimum gas cooling performance.

  The assembly of the support ring 12, the blow-off electrode 3, the inner cup 14, and the outer cup 15 with screws as shown in FIG. 2 has high stability and high heat capacity. The cooling channel formed by the gap further provides a strong contact of the hot gas screw connection, preferably with a metal part, with the result of the optimal cooling and simultaneous gas expansion described above.

It is a longitudinal cross-sectional view of the high performance spark gap of this invention provided with a pressure-resistant cooling space. FIG. 3 is an exploded view of individual components of a spark gap assembly arranged in a stack so that they can be distinguished.

Claims (12)

Two main electrodes spaced apart and opposite each other, a metal outer housing, at least one triggering means , a gas or plasma cooling space surrounded by the outer housing, and a main electrode Capsule-type, pressure-resistant, non-hermetic, rotationally symmetric high-performance spark gap with electrical connection contacts,
The cooling space is composed of a coaxial assembly consisting of an inner cup (14) and an outer cup (15), and one of the main electrodes is configured as a hollow cylindrical blowoff electrode (3) into the inner cup (14). Furthermore, a support ring (12) surrounding the blow-off electrode (3) from the side is provided on the open side of the cup assembly and connected to the outer cup (15) in a pressure-resistant manner. ,
The outer cup (15) is provided with a lateral gas outlet opening (16), at least one gas cooling channel (17) is provided between the inner and outer cups (14; 15) and another one. Spark gap, characterized in that two interstitial gas cooling channels (18) are located between the outer wall of the outer cup (15) and the inner wall of the outer housing (1). The blow-off electrode (3) has an annular flange (13) on the upper side facing the counter electrode (2) constituting the two main electrodes together with the blow-off electrode (3), and the flange (13) A support ring (12) having a complementary step is located adjacent to
The lower side of the blow-off electrode (3) has a closed shape with a lateral gas outlet opening (19) and is for complementary engagement with the recess (21) of the inner cup (14) The spark gap according to claim 1, further comprising an extending portion (20).   A guide extension (20) in which at least one gas cooling channel (22) extends into a screw hole (23) in the inner cup (14) forming a connection contact (24) with the inner cup (14). The spark gap according to claim 2, wherein the spark gap is located in a region below the blow-off electrode (3).   Each cup (14; 15) of the coaxial assembly comprises a circular ring connection piece (25; 26), and the circular ring connection piece (25) of the inner cup (14) is a circular ring of the outer cup (15). Attached to the connecting piece (26), the outer housing (1) is adjacent to the outer ring (26) in the region of the circular ring connecting piece (26), with the outer shape fitting together. The spark gap of any one of 1-3.   The pressure-resistant connection of the coaxial assembly (14; 15) including the support ring (12) and the blow-off electrode (3) is realized by force-fit and / or external-fit, in particular by screwing It is implement | achieved by these, The spark gap of any one of Claims 1-4 characterized by the above-mentioned.   A sleeve or disk (4) made of outgassing material is arranged between the main electrodes (2; 3), and a support ring (12) surrounds the sleeve or disk (4) at least partially at the outer periphery. The spark gap according to any one of claims 1 to 5, wherein: A trigger insulating sleeve (5) made of a gas releasing material is arranged on the sleeve or disk (4) on the side remote from the blow-off electrode (3), and the trigger insulating sleeve (5) has the at least one trigger means on it. 7. Spark gap according to claim 6, characterized in that it is followed by a trigger disk (6) made of a constituent conductive material, the trigger disk (6) being surrounded by a contact ring in the radial direction. . A bead-shaped insulator (8) is located above a trigger disk (6) with a contact ring (7) to trigger means (6, 7) for the outer housing (1) and the counter electrode (2). The spark gap according to claim 7, wherein electrical insulation is guaranteed. A counter electrode (2) facing the blow-off electrode (3) is formed as a disk (27) having a guide extension (28), and the guide extension (28) is a screw hole (29) for a connection contact. 9) The spark gap according to claim 8, characterized in that the journal part (9) made of a material having a burnout resistance is located at the center of the disk. Insulator further beaded shape (11) is provided disposed guiding extension of the counter electrode (2) to (28), the disc of the insulator (11) further, the counter electrode (2) ( 27) Spark gap according to claim 9, characterized in that it surrounds 27) from the side. 11. A spark gap according to claim 10, characterized in that a seal (10), in particular a seal ring, is arranged between the disk of the counter electrode (2) and the insulator (11). The contact ring (7) constituting the at least one trigger means is selectively drilled with a radial spot-like hole in the outer housing (1), and an insulator (8) located behind the outer housing (1). The spark gap according to any one of claims 7 to 11, wherein the spark gap can be exposed.

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