DE102013112400A1 - Arc extinguishing chamber for surge arrester e.g. encapsulated surge arrester, has gas exhaust region guided between metal sheets based on symmetry axis of extinguishing chamber, where gas streams are mixed in common recreation room - Google Patents

Abstract

The chamber has de-ionizing arc extinguishing metal sheets or extinguishing plates spaced such that channels are formed to receive arc gases. The extinguishing metal sheets comprise a slot-shaped inlet region and a gas outlet region by lateral- and/or front-sided apertures (7, 8) between the extinguishing metal sheets. The gas exhaust region is guided between neighboring pairs of the extinguishing metal sheets or mutually formed to a chamber side or chamber half and/or related separation bars based on a symmetry axis of the chamber. Gas streams are mixed only in a common recreation room. The metal sheets are made of a ferromagnetic material.

Description

The invention relates to an arc quenching chamber for surge arresters with a plurality of deionizing quenching plates or quenching plates, which are spaced so that a plurality of channels for receiving arc-induced gases is formed, the quenching plates have a slot-shaped inlet region and further a Gasausströmbereich by lateral and / or frontal Apertures between the quenching plates, according to claim 1. The invention also relates to a surge arrester comprising an arc extinguishing chamber, according to claim 13.

From the DE 10 2005 015 401 A1 a surge arrester with two diverging electrodes and a spark gap acting between the electrodes is previously known. According to the teaching there, the mobility of the arc is increased immediately after its ignition by a combination of measures to increase the arc-related internal magnetic field and a staggered gas circulation. In this regard, a special arc or Deionkammer is present, with constructive measures are implemented, which allows the gas circulation in multiple circuits with different functions. Both the gas flow from the arc chamber and any existing gas recirculation into the arc chamber takes place according to the known prior art via at least two channels. The return and cooling of the hot gases is preferably carried out laterally adjacent to the arc chamber. The return of the cooled gases takes place to a small extent directly in the ignition region of the arc between the diverging electrodes and their base and serves for deionization in this area.

The DE 10 2005 015 401 A1 refers not only to encapsulated surge arresters, but also discloses that openings to the environment and an arrangement for gas cooling can be provided.

To avoid the risk of re-ignition according to DE 10 2005 015 401 A1 by reducing hot gases, a quantity of gas passes through an additional area for intensive cooling. In this area, the gas is passed through narrow channels, preferably made of metal with a high heat capacity. The introduced in the arc chamber Deionbleche have in one embodiment on different height dimensions, so that the number of partial arcs is increased only gradually, ie with a time delay. According to DE 10 2005 015 401 A1 The inlet slots of the sheets can also be designed differently or asymmetrically to force a gradual division of the arc.

The gas outlet from the arc quenching chamber or Deionkammer after DE 10 2005 015 401 A1 takes place both through lateral openings and at the top of the chamber. The escaping gas on the sides, but also the gas on the top can be guided in separate, mutually insulated channels. A return of the gas to close the circulation can take place both in the ignition region through the electrodes and in the running region of the arc through openings there.

However, it has been shown that a simple channel formation for gas guidance is not sufficient to avoid reignition. In small spaces in DIN rail mounted devices, the hot gases from the Deionkammer occur relatively uncooled and have a considerable electrical residual conductivity. As a result, in the case of the deion chambers of the prior art, individual sheets can sometimes be bridged by electric arcs. This is the case even in the case of a completely isolated arc quenching chamber, since due to the resulting contraction, conductive channels result which lead to the undesired bridging mentioned above. This unwanted formation of partial streams, which gain in importance in particular by the encapsulation, reduces the arc voltage of a corresponding arrester and thus the resulting current limit. While such phenomena at relatively low operating voltages, such. B. 230 V, are still insignificant, the risk of a significant functional impairment increases at higher voltages, eg. B. the chained voltage, ie at 440 V or DC voltages considerably.

For this reason, lightning arresters with deion chambers for operating voltages of 440 V and more are designed exclusively for discharge. In order to still be able to realize a sufficient sequence current limit, the arc is divided in these arresters targeted, z. B. by a so-called splitter. The partial arcs are then each fed to a separate deionization chamber with comparatively low performance. Although it can be reduced by such a solution, the risk of bridging the arc chamber, but the Ausblasverhalten and the effort with several separate Deionkammern and the space required thereby unacceptable. In this regard, be on the DE 44 35 968 C2 directed.

From the foregoing, it is therefore an object of the invention to provide a further developed arc quenching chamber, which can be used with a Deionkammer in a small size for increased operating voltages and wherein at an optimal inlet velocity of the arc in the Deionkammer shunts by arcs or electrically conductive gases and flashbacks outside the Deionkammer are avoidable and / or the arc voltage of the partial arcs between the individual Deionblechen can be specifically increased.

It is a further object of the invention to provide a correspondingly developed surge arrester.

The object of the invention is achieved by the arc quenching chamber for surge arrester according to the combination of features according to claim 1, wherein the dependent claims represent at least expedient refinements and developments. The solution of the invention is also achieved by the surge arrester according to claim 13.

The proposed arc quenching chamber is used in particular for encapsulated surge arresters and surge arresters for the (damped) ausblasendem principle. The surge arrester can z. B. be designed for the derivation of lightning currents. The spark gap formed in the surge arrester may be a horn spark gap. The presented solution can be used at higher operating voltages, but also at DC voltages. According to the invention, a flow of current through the hot gases or also the ignition of partial arcs outside the deion chamber is avoided by a separate and insulated guidance of the venting gases of the deionized chamber. Due to the special type of targeted venting, the arc column between the individual deion plates is also extended and the running motion of the arc on the individual quenching plates influenced, whereby the achievable arc voltage can be significantly increased compared to chambers of the prior art.

It is therefore assumed that an arc quenching chamber for surge arresters with a plurality of deionizing quenching plates or extinguishing plates, which are spaced so that a plurality of channels for receiving arc-induced gases is formed, the quenching plates form a slit-shaped inlet region and further a Gasausströmbereich by lateral and / or frontal openings between the quenching plates consists.

Starting from the axis of symmetry of the arc extinguishing chamber, the gas outflow regions between adjacent pairs of extinguishing plates are each guided alternately to one or the other chamber side or chamber half and separating webs are formed in this respect, wherein the partial gas streams only meet in a common expansion space or are mixed there.

According to a further embodiment of the invention, the surge arrester is encapsulated and the arc extinguishing chamber is designed so that a targeted gas circulation within the encapsulation of the surge arrester can be predetermined.

In a further embodiment of the invention it is provided that in the aforementioned encapsulation to form the surge arrester, a horn-shaped, divergent electrode arrangement is introduced in the sense of a horn spark gap, wherein the electrodes have recesses for the realization of the gas circulation.

The separating webs for obtaining a targeted gas guidance can be components of the encapsulation or of the housing of the overall arrangement.

The electrode assembly includes the arc extinguishing chamber laterally. In this regard, therefore, the arc extinguishing chamber immersed in the electrode gap.

According to a further embodiment of the invention, the end faces of the quenching plates, which form the slot-shaped inlet region, are provided with an insulation cover, which may also be designed as a flow-conducting cover or flow-guiding device.

In a preferred embodiment, this insulation cover has a comb shape or is in the form of a hood with comb-like edges.

The quenching plates for the Deionkammer can consist of a ferromagnetic material.

With regard to the hood having the comb shape, one comb tooth can cover at least two adjacent quenching plates and the space defined by them.

The recesses between the respective comb teeth can correspond approximately to the width of the aforementioned gap.

The recesses between the respective comb teeth of the two opposing ridges forming the cover are offset by a gap.

The structural design of the arc quenching chamber is selected such that the area of the gas inlet region is substantially equal to the sum of the area of the lateral and / or end gas outlet openings.

The invention will be explained below with reference to an embodiment and with the aid of figures.

Hereby show:

1 a schematic sectional view of an encapsulated spark gap with Deionkammer and symbolically indicated internal gas circulation according to the prior art;

2a a side view of an encapsulated spark gap according to a first embodiment of the invention with Deionkammer;

2 B a sectional view through the spark gap according to 2a ;

3 a sectional view of a spark gap with attenuated Ausblasendem behavior according to a second embodiment of the invention;

4 a sectional view of a spark gap with attenuated Ausblasendem behavior according to a third embodiment of the invention;

5 a sectional view of a spark gap with attenuated Ausblasendem behavior according to a fourth embodiment of the invention;

6 a sectional view of a spark gap with attenuated Ausblasendem behavior according to a fifth embodiment of the invention;

7 a sectional view of a spark gap with attenuated Ausblasendem behavior according to a sixth embodiment of the invention;

8th a side view of a spark gap with attenuated Ausblasendem behavior according to a seventh embodiment of the invention;

9 a schematic side view of a Deionkammer with slit-shaped inlet area;

10 a side view of the Deionkammer with frontal cover of the deion plates used;

11a a perspective view of the Deionkammer with comb-like cover;

11b a perspective view of the Deionkammer with dividers and the separate gas recirculation channels formed therefrom;

12a a sectional view of a gap between two Deionplatten with ventilation in right-hand orientation;

12b a sectional view, similar to 12a but with left-side venting;

12c a plan view of the inlet region of the Deionkammer (see also 11a) with partially broken cover and the recognizable comb structure of the cover;

13 a sectional view of the Deionkammer with lateral representation of a Deionblechs with indicated basic migration of a partial arc and

14 a longitudinal sectional view of the Deionkammer with the indicated arcing and the resulting flow.

The basis for a high subsequent current limit with a Deionkammer is the rapid and stable division of the arc. In order to achieve a rapid arc splitting in the case of an encapsulated arrester on the horn principle, the arc must rapidly run into the deion chamber after the arrester has responded. In the DE 10 2005 015 401 A1 For this purpose, a few fundamental possibilities are described for an encapsulated horn spark gap with a deion chamber. Since the possibilities for increasing the forces acting on the arc, forces are relatively limited, the way to the shrinkage, the length of the arc and the width of the Deionkammer and the flow resistance should therefore be as low as possible.

1 shows a basic arrangement of a horn spark gap with Deionkammer 1 corresponding DE 10 2005 015 401 A1 , with a through insulation plates 2 laterally limiting arc run area and electrodes 3 with lateral recesses 4 for an internal gas circulation 5 , The Deionkammer is at the front and on the sides of an insulating material 6 surrounded, which has openings through which gases can escape from the areas between the individual Deionblechen. The openings 7 . 8th are located laterally 7 and at the front 8th the Deionkammer. The position of the openings for venting the subsequent intermediate plate areas preferably varies, so that the openings of adjacent spaces are not immediately adjacent to each other. A gap is here by two Deionbleche 10 limited and will be on both sides 7 the chamber and the front 8th vented. The lateral edges 9 the deion plates 10 are in the inlet area through the insulation plates 2 , in which additionally a ferromagnetic plate 11 can be used to amplify the intrinsic magnetic field of the arc, covered.

2 shows an inventive design of an optimized Deionkammer for a encapsulated spark gap according to the horn principle. 2a shows the side view of the horn spark gap with the two diverging electrodes 3 , an ignition electrode 12 with trigger circuit 13 , The electrodes have bilateral recesses 4 to realize a targeted internal gas circulation. The recesses lead the cooled gases into the arc run area between the divergent electrodes 3 back. The arc run area is laterally through the insulation plates 2 (see also 2 B ) limited. The inlet region of the Deionkammer begins immediately below the same and can be within the V-shaped recesses of Deionbleche (see 2 B ) narrow further. The inlet area also includes the transition area between the electrodes and the deion chamber. This area also affects the rapid entry of the arc into the chamber. In this area too, an almost unhindered flow of the hot gases is to be ensured. These gases are collected above the electrodes and also integrated into the circulation circuit. The gases may possibly also in the region of the chamber and in addition to the electrodes or by further lateral recesses on the electrodes out to a channel behind the electrodes. The cross sections for the gas guide can be made very variable in this area, as there is a very good cooling by the electrodes and side or rear of the electrodes there is no danger of bridging chamber areas by partial arcs. The rapid formation of partial arcs and their rapid migration between the respective outer deion plate of the chamber and the electrodes is necessary so that the bases on the electrodes do not remain below the chamber to avoid prolonged ionization in the arc run area and also at the ignition area. This could cause unwanted flashbacks.

The outflow area 16 the Deionkammer is made up of the lateral openings 7 and the frontal openings 8th per plate gap together. The venting of a plate gap takes place only to one side of the chamber based on the axis of symmetry, since the openings 7 and 8th are arranged only on one side per gap. The successive plate interspaces are vented alternately forward or backward. In the middle of the front of the chamber is a bridge 14 executed, which leads to that in the 2a shown venting of a plate gap in each case via three openings (two lateral, one end face) takes place, and their gases in a separate channel 17 with double-sided isolation bars 18 laterally next to the chamber into a shared relaxation room 19 be performed in which at the earliest mixing with gases from another plate gap can be done.

In order to keep the flow resistance of the Deionkammer relatively low, the V-shaped inlet area should 15 and the outflow area 16 only moderately dammed and have a streamlined design as possible. The inlet area should preferably be not more than 50% dammed with respect to the arc running area below the chamber. In the Deionkammer 1 itself, the cross-section should increase again. The sum of the outlet cross sections between the individual deion plates should as far as possible not result in any obstruction within the chamber. If an increase in the flow resistance in the chamber is necessary, this should be max. 50%. In order to avoid a high flow resistance, in addition to the outlet cross sections of the chamber, its geometric configuration and the design of the gas flow in the return channels and, in turn, also the cross section of the return channels 17 really important. The cross-section of the individual return channels should not be less than 25% of the cross-sectional area between the individual deion plates.

In order to realize an optimal gas circulation within the encapsulated spark gap, in addition to the venting of the deion chamber, there is also a purposeful return of the gases into the arc inlet region below the deion chamber, for example through the recesses 4 in the electrodes 3 , necessary.

According to the invention, the interspaces of the deion plates are bled alternately with respect to the axis of the deion chamber. The venting is preferably carried out, both laterally and frontally of the Deionkammer. The gases emerging from the deionized chamber are taken in separate channels per space. The individual channels are here, for example, by webs 18 , which are directly connected to the insulating material of the chamber, separated from each other without gaps. The projections of the webs are at least twice as large as the wall thickness of the Deionkammermaterials 6 , The laterally projecting webs can be made the same height, but also different heights on one side. At the front of the Deionkammer are the individual venting channels, for example, by an axially extending to the Deionkammer middle web 14 , also separated from each other. The number of lateral separate channels 17 rounded on each side of the chamber thus corresponds to half the number of Deionbleche.

Instead of an insulating sheath of the Deionkammer z. B. with webs, of course, the Deionbleche or a simple open Deionkammer can be used in accordance enveloping housing parts in which the preferred vent geometry is integrated. in this connection Then, for example, isolation webs from the housing parts mutually partially engage between the deion sheets. Likewise, such an embodiment can also be realized as a stacked geometry of in each case one insulation element and one deion plate as an insert part or as an element to be encapsulated. Of course, the numerous possibilities for realizing an inventive chamber can not be represented here. The further embodiments are therefore limited to an exemplary embodiment and its function.

As a result of these additional insulation elements, which are designed for example as webs, which is caused by the small size surface of the Deionkammer is additionally increased, so that sliding arcing due to hot gases or contaminants can be avoided even more effectively and thus a significant increase in the isolation capability can be achieved.

For the desired rapid shrinkage of the arc in the Deionkammer it makes sense not to hinder the running of the arc on the electrodes, which laterally border the Deionkammer, by a too strong damming of the Deionkammer, not to hinder. Also the gas flow between the electrodes 3 and the Deionkammer 1 The circulation is specifically supplied within the entire spark gap.

The separate guidance of the gases need not necessarily take place up to the return flow channels within the horn electrodes. Sufficient is a separate gas guide until the gases have cooled down so far that a flow of current through these gases is ruled out. Below the Deionkammer and z. B. on both sides parallel to the arc running range, the gases in a corresponding relaxation space 19 be merged.

In a preferred embodiment, in which the return of the gases in the running region of the arc over, for example, lateral recesses 4 takes place in the electrodes, the gases from the Deionkammer are laterally divided into two streams, whereby all four gas recirculation (each electrode on both sides) is forcibly subject to a gas reflux. The arc is thereby accelerated into the Deionkammer driven. However, the sum of the individual cross sections of these return channels is preferably only less than 10% in relation to the entire vent cross section of the deion chamber.

3 shows a sectional view of a spark gap with damped Ausblasendem behavior. The gas from the Deionkammer 1 comes out of the openings 7 and 8th in the mutually isolated channels 17 and enters the relaxation rooms 19 , Subsequently, the already cooled and relaxed gas, for example, by meander (plates (metal cooling) or webs (insulating-deflecting) on additional openings 29 in the case 28 directed to the outside.

4 shows a sectional view of another spark gap with attenuated Ausblasendem behavior. The cooling plates are arranged in the flow direction. The plates can be directly at the openings of the channels 17 begin, whereby in modified embodiments of the invention also on the relaxation room 19 can be waived.

In the 5 shown spark gap is similar to those in 3 , but have the baffles after the relaxation room 19 only openings which are offset from each other. Even with this arrangement, these plates can be relatively close below the openings of the channels 17 begin or even in the mutually isolated channels 17 be integrated, which also the relaxation room 19 eliminated.

6 shows a spark gap, in which the gases are not deflected relative to the flow direction in the arc running area along the electrodes after the Deionkammer. The gases are from the mutually isolated channels 17 after leaving the Deionkammer 1 in a meandering channel to the outer wall of the housing 28 guided and through openings 29 delivered to the environment.

In 7 is shown a spark gap, where the gases from the channels 17 above the Deionkammer 1 deflected and, for example, cooled on one side parallel to the arrangement of the spark gap by a meander system and guided to the outside.

8th shows a side view of another spark gap arrangement. The gases, after leaving the Deionkammer through the openings 7 and 8th in the isolated channels 17 guided deflected and insulated in addition to the running range of the spark gap. Thereafter, the already cooled gases within the housing 28 delivered into an area which openings 29 owns to the environment. These openings 29 may be located in the area of the terminals, for example. The inlet area of the deion chambers is endangered in particular by the complete encapsulation of the spark gap and the movement of the arc base points on the deion plates of flashbacks. In this case, in particular two areas are to be distinguished, on the one hand the immediate end faces next to the generally V-shaped inlet area of the Deionbleche and on the other hand, the V-shaped inlet area itself.

9 shows these two areas. The sheets 10 the Deionkammer are in the insulation jacket 6 , which surrounds the deion chamber at the front and sides, guided. The edges 9 the sheets next to the V-shaped inlet area are generally free. The V-shaped inlet area 15 has in the representation z. B. yet another slot-shaped opening 20 , Flashbacks are without additional measures in the area 9 and 15 / 20 possible.

In a preferred embodiment of the area of the arc migration corresponding to 2 B and 3 to 8th from the ignition point to the Deionkammer with a two-sided plate-like demarcation makes sense, the immediate end faces 9 the Deionkammer 1 through these plates 2 already cover. Should it be necessary to narrow the V-shaped inlet area, z. B. accordingly 10 to design, as the respective arc running range (plate distance), can be attached to the plates 2 preferably ramp-shaped tapers 21 be mounted from insulation material, which also the edges 9 the deion plates 10 cover. Such an embodiment may, for. B. be used when a large width of the electrodes and the arc running range for aging-resistant behavior or to control high pulse currents is required, while the thermal load of the Deionkammer is also controlled with a small heat capacity.

Of course, the side plates 2 , the rejuvenations 21 or the Deionkammer 1 be designed so that they each intermesh web-like and, for example, from the housing material 6 can be formed to encapsulate the spark gap.

The V-shaped inlet area of the Deionbleche 15 In conventional embodiments of the Deionkammer by the movement of the arc base points on the Deionplatten due to the magnetic forces by leaks of individual partial arcs often affected by partial or complete bridging. However, this is generally not critical in the case of a customary design of the arc chamber for an operating voltage of, for example, 230 V and for AC voltage.

In the preferred embodiment of the deionization chamber, the number of deionic plates used, based on the desired operating voltage (eg 440 V), is up to 40% smaller compared to the prior art. This can only, as already explained, be realized by the strong extension and cooling of the arc in the Deionkammer, whereby the proportion of the arc voltage from the arc column (length-dependent) is almost equivalent to the arc voltage due to the anode / cathode drop voltage (depending on the material) and thus according to the known arc equation (arc total voltage = anode / cathode drop voltage + arc column length · electric field strength of the arc) a sufficiently large total voltage can be realized. By influencing the running behavior of the arc between the Deionblechen not only the good cooling of the arc, the total voltage is also increased by the ohmic resistance of the current flow in the actual Deionblech. By selectively influencing the arc migration, the length of the current path in the deion plate is maximized. The total voltage can thus also on the material z. B. the specific electrical resistance are more affected than in conventional chambers.

But if it comes in this case to bridge individual plates, not only reduces the total voltage to the anode / cathode drop voltage, but in addition to the proportionately very high voltage of the arc column section of the respective arc loop and the ohmic voltage drop of the current path in the sheet. This would inevitably lead to a dramatic reduction in follow current limiting. Flashbacks in the V-shaped inlet region of the Deionbleche or a bridging of portions of the chamber by lateral flashovers or partial flow of current through escaping hot gases are therefore mandatory to avoid.

It should be noted, however, that the rapid entry of the arc into the chamber, by the appropriate measures, is not affected, since this is the basic requirement for a rapid and thus optimized current limit.

According to the invention this is achieved by an insulating cover of the V-shaped inlet region of the Deionbleche, which only slightly affects the flow resistance of the chamber. A corresponding embodiment is in the 11a and 11b shown. In this embodiment, the cover of the front side of the Deionbleche next to the V-shaped inlet region can be realized simultaneously by a hood-shaped cover.

For covers which cover the inlet area on both sides and evenly, the flow resistance of the Deionkammer is significantly increased. The shrinkage of the arc is significantly delayed or even prevented especially in encapsulated spark gaps, in which the flow resistance is already increased in any case with respect to the blowout switches or spark gap. A satisfactory follow current limiting is therefore no longer possible, especially at high prospective follow currents. According to the invention, the cover is made, for example, comb-shaped, so that in each case two adjacent sheets on each side of the cutout are insulated from each other. This ensures that the flow resistance of the V-shaped inlet region, in particular immediately before the desired division of the arc is increased only relatively small, whereby a rapid immigration of the arc is made possible in the chamber.

In 11a is the comb-shaped cover of the V-shaped inlet area through the parts 22 realized on both sides of the chamber. Between the recesses of the comb of the cover are on each side two deion sheets. The recesses in the comb 23 are each about as wide as the space between the deion plates and allow the unilateral entry of gases into this space already below the sheet edge and the end of the comb. The direct flashover between two adjacent Deionblechen or the exit of partial arcs from the chamber in the slot-shaped inlet region is due to the comb teeth 24 , which in each case two Deionbleche and a gap overlap, however, not possible. The cover of the opposite side of the V-shaped inlet region of the Deionbleche done in the same manner, but each offset by a sheet. The height at which the comb-shaped cover begins substantially determines the confinement factor of the chamber in the inlet region. The end of the comb teeth can be guided to the end of the V-shaped inlet region.

The cover of each two adjacent Deionplatten by the comb teeth prevent the flashbacks in the inlet area safely. Due to the mutual recesses in the comb (ridge valleys), however, the flow resistance is hardly increased, in contrast to a complete cover, so that an unfavorable influence on the inlet velocity and thus the current limit is avoided.

The hot gas, which is in front of the arc in the running area between the divergent electrodes 3 is displaced, can flow under the sheets each mutually between two Deionbleche in the region of the recesses of the comb (ridge valleys) in the chamber, creating a backwater or a reflection below the inlet region 15 avoided or significantly reduced.

In one embodiment of a deionization chamber according to the invention, the following dimensions are provided (in each case vertically, for example, corresponding to the axis of symmetry):
Height of the inlet area in the Deionblech 10 : 8.7 mm
Height of the sheet overall: 19.7 mm, width: 22.3 mm
Height of the comb teeth 24 : 6.7 mm
Height of the ridge valley 22 : 3.4 mm

In other embodiments of the invention, the dimensions are within the range +/- 50% to the above values, in particular in the range +/- 25% to the above values.

In further embodiments of the invention, it is provided that with regard to the height of the recess of the inlet region in the deion plate, the comb chambers make up at least 20% and the comb teeth at least 30%.

Preferably, the height of the cover valley is about 39% and tooth about 77%.

In a preferred embodiment, 90% of the height of the recess of the inlet region in the deion plate are not exceeded as an upper dimension for the comb teeth.

The arc quenching chamber or the surge arrester can be designed so that it is suitable for a 2TE (DIN rail mounted devices 36 mm) version. The relative ratios are crucial and can be applied to smaller chambers z. B. for 1TE (18 mm) transferable.

The hot gas (see also 11b ) can after unilateral influx in a space between two Deionbleche 10 this space only on one side of the chamber through the lateral recesses 7 or the one-sided located on the side of the symmetry axis of the chamber frontal recess 8th escape the Deionkammer. The through the openings 7 and 8th Gases escaped from a space between two deion plates are each in a separate return channel 17 caught. The return channel 17 becomes laterally through the isolation webs 18 and frontally through the bridge 14 limited. The gases from the spaces between the deion plates are thus mutually and separated from each other in the return channels 17 to the relaxation room ( 19 , see, for. B. 2 B ) guided. A flow of current through the hot gases after passing through the Deionkammer is reliably prevented by the separate return channels as well as a partial bridging by arcing. Thus, no unwanted or no stochastic reductions in the arc voltage occur.

Due to the preferably mutual flow of the gases into the respective interspaces of the deion chamber and their mutual venting, particularly favorable flow conditions are created within this arrangement, whereby, despite reduced flow cross-sections, the rapid shrinkage of the arc and its division relative to a known and non-insulated chamber can be realized and possibly optimized. The 12a shows the arc 25 below the inlet area 15 and the gas flow into the space between two deion plates 10 through the recess in the comb 23 and above the comb teeth 24 , The space in the chamber is above the vents 7 . 8th vented on one side on the right side of the chamber. The 12b shows the gas flow through the chamber between the immediately adjacent arc plates with the vents on the left side. The gases from a gap between two deion plates are in the respective separate return channels 17 summarized again and on the respective chamber side to the relaxation room 19 or finally cooled to the recesses 4 in the electrodes 3 guided, resulting in a closed gas circulation within the spark gap. 6c shows the front of the chamber with the inlet area 15 , the individual deion plates 10 , the vents 7 . 8th the plate interspaces and separate gas return channels 17 ,

The presented type of protection against flashbacks in the V-shaped inlet area also allows the safe use of Deionbleche due to the Fußpunktwanderung the partial arcs still directly in the respective edge of the Deionbleches laterally next to the V-shaped inlet area. The Fußpunktwanderung of the arc in this area is still possible because it can not come to a jam of hot gases in this area of the chamber, because at any time the ventilation through the comb-shaped running cover to the interior of the Deionkammer and the vent on the side or given the frontal vents.

The 13 shows an example of the basic running behavior of an arc on a Deionblech 10 after the arc distribution on the individual sheets in the slot-shaped inlet region of the chamber. After the division of the arc 25 The base of the partial arc of light wanders on the sheet 10 in the form of a loop to an edge region of the V-shaped inlet region. Without frontal covers 9 . 24 It may come to the escape of the arc from the chamber and the arc must be redistributed. The deion plates 10 can help prevent crevices or soiling and creepage paths in the insulating cover 6 the chamber in the area of the edges 9 or be recessed all around. The comb-shaped cover prevents this leakage without the time is increased until the arc distribution by the confinement of the inlet region. The arc is both on the front side 9 as well as in the slot-shaped V-area 24 prevented from re-exit. The partial arc remains in the flank area of the deion plate until the end of the arc phase. The dashed path shows the basic running behavior of the foot of the partial arc in the subsequent intermediate chamber on the back of the same Deionbleches.

Due to the completely reciprocal flow and deaeration of the interstices of the deion chamber (see, for example, US Pat. 12c ), the movement of the arc column is essentially influenced by the magnetic forces. The entering into the chamber arc is deflected by the mutual vent already entering different sides in the individual intermediate chambers and extended to the division. The arc deviates here from the direct flow through the gases in the plate interspaces. In the plate interspaces of the adjacent chambers thus arise already laterally offset partial arcs, which also migrate in opposite directions and be extended. This results in a very effective increase in the total length of the arc column. In addition, the Deionbleche, which preferably consist of a material with ferromagnetic properties and generally have poor thermal conductivity, each loaded on the front and back only in different areas by the arc. It is therefore used in contrast to other solutions, the full area of the plates for cooling the arc and optimally utilized the heat capacity of the plates. This is also favorable for the aging of the plates, since so the local overheating and burnup and the formation of molten beads of the material can be very well prevented.

As a result, several positive effects occur. In Deionkammern the partial arcs i. A. in the vertical direction from each other. In conventional chambers therefore moves a partial arc on the plate to the upper end of the chamber, while the other migrates to the lower end face with the inlet region. For chambers without cover and with low sheet height, this almost inevitably leads to flashbacks below the arc chamber. The Deionblech is also often heated on one side and partially overloaded.

Due to the mutual deflection of the partial arcs transversely to the current flow direction (chamber axis), the vertically acting repulsive forces on the partial arcs in the inventive Deionkammer are drastically reduced and the forces act rather an additional horizontal force. The mutually deflected successive partial arcs heat, as already mentioned, the common plates are not nearly punctiform on both sides, but move on completely opposite areas of the plates. Since the sheets i. A. have a very poor heat conduction, thereby the maximum heat capacity of the sheet is used to cool the arc. This increases the arc voltage and prevents premature aging of the sheets.

The 14 shows a basic arrangement of the partial arcs 26 in the Deionkammer between the individual Deionblechen 10 with respect to the longitudinal axis of the chamber in plan view. The ionized by the partial arcs gas is already before leaving the plate interspaces through the opposite outlet openings 7 . 8th cooled by the deion plates, whereby a Rückzündgefahr and a flow of current through the hot gases outside the chamber is further reduced.

In the 13 and 14 it becomes clear that the current path 27 is almost maximized within the individual sheets from the base of the arc on one side of the sheet to the current outlet in the base point region of the following partial arc on the same plate in the inventive Deionkammer. The length of the route and the forced passage of electricity over the slot-shaped area of the sheets ( 13 ) leads in addition to long distances (several centimeters) also to increased current densities in the sheet and thus to an increased ohmic voltage drop in the sheet material. In the case of conventional deion chambers, on the other hand, only the material thickness of the metal sheet (eg <1 mm) sometimes acts as an impedance.

Without a reduction in performance, an efficient use of material and space or, alternatively, an increase in performance is thus made possible, which is of paramount importance particularly in the case of encapsulated DIN rail mounted devices.

Due to the geometry of the Deionbleche and the material, the proportion of the ohmic voltage drop or the Fußpunktbewegung can be used specifically and reproducibly to influence the arc voltage. In addition to a homogeneous material of the deion sheet, it is of course also possible to use coated, laminated or also sheet metal with targeted internal current conduction in order to further increase the ohmic voltage drop. By stratification of electrically conductive and poorly conductive material up to insulating intermediate layers possibly with local feedthroughs, the current path and its impedance as well as the arc movement can be additionally influenced. These known measures for the design of quenching plates can be used very effectively in the present chamber design, in particular due to the reproducible movement of the arc.

The illustrated Deionkammer leads to a very stable and reproducible arc behavior without the stochastic phenomena of flashbacks despite significant increase in the arc voltage per Deion sheet.

The inventive design of the Deionkammer leads to a reproducible significant increase in the achievable partial arc voltage per Deionblech. The arc voltage is very constant after the complete division and free of voltage dips, whereby a very high and reproducible current limitation in alternating and DC currents is possible. The Deionkammer is due to the isolated gas recirculation particularly suitable for encapsulated switching devices with closed gas circulation.

The most optimal behavior is achieved by the targeted mutual ventilation of the individual chamber interspaces into complete separate and isolated channels. The closed loop gas flow within the device from the arc firing area to the inlet area of the chamber, through the chamber into the outflow area of the chamber, into the flash area and back into the arc run area between the diverging electrodes, is tuned to direct the flow and the flow Cross sections lead to no impairment of the arc movement and the arc distribution despite the encapsulation of the arrangement. By the measures described, the very dynamic movement of the arc and the possibility of full-scale utilization of the chamber for cooling effect using the Deionbleche optimally realized. The targeted gas flow and the measures already described, the arc column can be effectively extended and cooled so that the voltage component due to the arc column and the ohmic voltage drop in the sheets in the total voltage can be up to 50%, with conventional Deionkammern this proportion is usually smaller 10% is.

With the inventive Deionkammer the achievable voltage per Deion sheet over the prior art can be increased by well over 30%. A leakage of partial arcs from the inventive Deionkammer with comb-like confinement can be almost eliminated after the complete division of the arc in the chamber, whereby very constant and minimum Durchlaßintegrale be achieved in a Kurz-schlussstromabschaltung. The chamber allows this with a minimum space and material usage.

LIST OF REFERENCE NUMBERS

1

Deionkammer

2

lateral insulation plate

3

Electrode, diverging

4

lateral recess in electrode

5

gas circulation

6

isolation

7

lateral recess in Deionkammer

8th

frontal recess in Deionkammer

9

Edge of the deion plate in the inlet area

10

Deionblech

11

ferromagnetic plate

12

trigger electrode

13

trigger circuit

14

Insulation wall (bridge)

15

V-shaped inlet area

16

outflow

17

Feedback channels

18

Insulation web / divider

19

relaxation room

20

slotted opening

21

Rejuvenation, ramp-shaped, insulating

22

Cover, comb-like, insulating

23

Recess in the comb-shaped cover

24

Comb teeth of the cover

25

Electric arc

26

Partial arcs

27

current path

28

casing

29

opening

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102005015401 A1 [0002, 0003, 0004, 0004, 0005, 0045, 0046]
• DE 4435968 C2 [0007]

Claims (13)

Arc quenching chamber for surge arresters with a plurality of deionizing quenching plates or extinguishing plates, which are spaced so that a plurality of channels for receiving arc-induced gases is formed, the quenching plates have a slot-shaped inlet region and further a Gasausströmbereich by lateral and / or frontal openings between the quenching plates is characterized in that, starting in each case alternately to one or the other chamber side or half of the chamber out of the axis of symmetry of the arc extinguishing chamber, the Gasausströmbereiche between adjacent splitter plate pairs and this regard separating webs are formed, in particular the gas partial streams are only mixed in a common relaxation room. Arc quenching chamber according to claim 1, characterized in that the surge arrester is encapsulated and the arc extinguishing chamber is formed so that a targeted gas circulation within the encapsulation of the surge arrester can be predetermined. Arc quenching chamber according to claim 2, characterized in that in the enclosure a horn-like, diverging electrode arrangement is introduced, wherein the electrodes of the electrode arrangement have recesses for the realization of the gas circulation. Arc quenching chamber according to one of the preceding claims, characterized in that the separating webs are part of the encapsulation or of a housing. Arc quenching chamber according to claim 3, characterized in that the electrode arrangement comprises the arc extinguishing chamber laterally and in this respect dips the chamber in the electrode gap. Arc quenching chamber according to one of the preceding claims, characterized in that the end faces of the quenching plates, which form the inlet region, are provided with an insulation cover, which can be formed as Strömungsleitabdeckung. Arc quenching chamber according to claim 6, characterized in that the insulation cover has a comb shape or is in the form of a hood with comb-like edge. Arc quenching chamber according to one of the preceding claims, characterized in that the quenching plates consist of a ferromagnetic material. Arc quenching chamber according to claim 7, characterized in that in each case a comb tooth covers at least two adjacent quenching plates and the space defined by these intermediate space. Arc quenching chamber according to claim 9, characterized in that the recesses between the respective comb teeth correspond approximately to the width of the intermediate space. Arc quenching chamber according to claim 10, characterized in that the recesses between the respective comb teeth of the two, opposite combs are arranged offset by a gap. Arc quenching chamber according to one of the preceding claims, characterized in that the surface of the gas inlet region is substantially equal to the sum of the area of the lateral and / or end Gasausströmöffnungen. Surge arrester comprising an arc extinguishing chamber according to one of the preceding claims, in particular encapsulated surge arresters or surge arresters with sparking spark gap.

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