GB2421119A

GB2421119A - Extinguishing chamber of a circuit chamber

Info

Publication number: GB2421119A
Application number: GB0520745A
Authority: GB
Inventors: Ferdinand Valent; Ludovit Jurcacko
Original assignee: Hess Trading Sr Spol S R O
Current assignee: Hess Trading Sr Spol S R O
Priority date: 2004-12-08
Filing date: 2005-10-12
Publication date: 2006-06-14
Anticipated expiration: 2025-10-12
Also published as: GB0520745D0; CZ20041197A3; CN1787139A; CN100568431C; GB2421119B; SK287234B6; DE202005019323U1; SK50992005A3

Abstract

An extinguishing chamber (10) is disclosed for a current circuit-breaker (100) or other device having disconnecting contacts. The chamber comprises a box (1) for location next to disconnecting contacts. The box has pair of side walls (11) and a rear wall (12). Deionization plates (13) made generally of ferromagnetic material are installed in the box perpendicularly to its walls. The walls of the box are formed with holes (111,112) designed to exhaust gases from the extinguishing chamber. The holes are divided into two groups (111, 121). The holes of the first group (111) are made in both the side walls of the box for connecting the area of the box via exhaust channels (101) with the area of the disconnecting contacts. The holes of the second group (121) are made in the rear wall of the box with free exhaust outside the extinguishing chamber.

Description

Extinguishing Chamber of a Circuit-breaker

Technical Field

The invention deals with current circuit-breakers that automatically interrupt the electric circuit when the value of the passing current has exceeded a certain limit set for the circuit-breaker In particular it deals with extinguishing chambers for such circuit-breakers, where in these chambers the electric arc, that is generated after separation of the contacts of the switch in the circuit-breaker, should be extinguished rapidly

Background of the Invention

At present, information is available about many types of extinguishing chambers of current circuit-breakers while a common design of such chambers consists in a box divided into more sections that are separated with plate-like partitions. Such a chamber is usually open at the entrance side while the electric arc from the current contacts is directed to the opening After disconnection of the contacts the electric arc is lit while ionized gases expand in the space around the contacts and the electric arc moves to the extinguishing chamber, the purpose of which is to extinguish it as quickly as possible The arc is extinguished in individual sections of the extinguishing chamber where the originally higher voltage is divided into a series of lower voltages in individual sections while these voltages are not sufficient to maintain the arc and the arc is extinguished To ensure resistance and long life of the whole circuit-breaker it is important for the arc to be extinguished as quickly as possible, which is supported by creation of exhaust holes in the extinguishing chamber in known chamber designs These 2/ holes are either made in the rear wall of the extinguishing chamber or in the side walls of the chamber while the gases are exhausted outside the inner space of the circuit-breaker in both the above-mentioned alternatives This way, quite good results are achieved with regard to the speed of arc extinguishing or disconnection times of the circuit; however, there are still reserves concerning exhaust of gases from the extinguishing chamber, where such a solution could increase the short-circuit resistance of the circuit-breaker as well as prolong its life from the point of view of repeated disconnections in case of a short-circuit situation

Summary of the Invention

The above mentioned limitations concerning current and time are reduced and a current circuit-breaker with shortened disconnection times, with an increased short-circuit resistance and a longer life is produced with the use of a extinguishing chamber in accordance with the presented invention, where the extinguishing chamber has the form of a box positioned next to the disconnection contacts and consists at least of the side walls and the rear wall, where in this box deionization plates based on ferromagnetic material are installed perpendicular to these walls and where the walls of the box contain holes designed for exhaust of gases from the extinguishing chamber and where the principle is that the holes are divided into two groups while the holes in the first group are connected to exhaust channels interconnecting the space of the box with the space of the disconnecting contacts and the other group of holes is created in the rear wall of the box with free exhaust outside the extinguishing chamber It is beneficial if the deionization plates are made of ferromagnetic material, especially with a surface finish of material resistant to high temperatures and oxidation. It is especially beneficial if the surface finish of the deionization plates consists in copper-plating. It is also advantageous if the deionization plates have an angular cut-out in the front part In a beneficial version the axis of the angle of the cut-out is alternately diverted to one and to the other side from the longitudinal axis of the extinguishing chamber. The holes of the first group are beneficially positioned gradually in individual spaces between the deionization plates, alternately in one and in the other side wall of the box The holes of the box belonging to the second group made in the rear wall of the box are beneficially positioned in individual spaces between the deionization plates,alternately nearer one and the other side wall What is a preferred advantage is if in each space between the deionization plates there is just one hole in a side wall and one hole in the rear wall of the box In such a case it is an advantage if in one space between the deionization plates the hole that is made in the rear wall of the box is positioned further away from the side wall in which the other, i e lateral hole of the particular space is made It is also beneficial if the side and rear holes can have a rectangular cross- section while with a small height of the space between the deionization plates an optimum cross-section of these holes is achieved Finally, it may also be beneficial if the total area of the side holes is smaller than the total area of the rear holes In such a case the decisive pressure drop in the box will be ensured through direct exhaust from the box, but at the same time re-blowing of gases back to the contacts will be ensured in a sufficient quantity to support the exit of the arc or pushing the arc off these contacts.

This way a current circuit-breaker is created that has an improved extinguishing chamber and with compact dimensions shows a high resistance against short-circuit loads, a relatively long life and achieves significantly shorter times of circuit interruption as compared to hitherto top versions.

Brief Description of the drawing

The presented invention is further described and explained in a more detailed way with the use of a sample design, also with the use of the attached drawings where Fig. 1 presents a perspective view of a crosssection of the circuit-breaker with the box of the extinguishing chamber and Fig. 2 presents a longitudinal horizontal cross-section of the same circuit-breaker while the circuit breaker is cross-sectioned in the area between the deionization plates

Description of the Preferred Embodiment

The current circuit-breaker 1Q contains a extinguishing chamber 10 the principal part of which is a box 1 This box 1 is delimited by the side walls 11 and the rear wall 12 and is positioned next to the disconnection contacts that are not shown here. In this box 1 deionization plates 13 made of ferromagnetic material are positioned perpendicular to these walls 11, 12 while the surface finish of these plates consists in copperplating. In the walls 11, 12 of the box 1 holes ijj., ij are made that are designed for the exhaust of gases from the extinguishing chamber while the holes i?J are divided into two groups, where the holes of the first group 111 are made in the side walls 11 of the box 1 and where these holes 111 in the first group are connected to exhaust channels 101 interconnecting the space in the box 1 with the area of the disconnecting contacts, not shown here, while the second group of holes 121 is made in the rear wall 12 of the box 1 with free exhaust outside the extinguishing chamber. In this design the deionization plates 13 have an angular cut-out 131 in their front part. In this case the angular cut-out 131 is arranged symmetrically to the longitudinal axis of the box j, but it may be especially beneficial if the axis of the cut-out 131 is diverted to one or the other side from the longitudinal axis of the box 1 of the extinguishing chamber 10 The holes of the first group 111 made in the side walls 11 of the box are gradually positioned in individual spaces between the deionization plates 13, alternately in one and the other side wall ii of the box 1 The holes 121 in the box 1 belonging to the other group, made in the rear wall 12 are gradually positioned in individual spaces between the deionization plates, alternately nearer one and the other side wall 11. In particular, in this design in each space between the deionization plates 13 there is just one side hole in a side wall and just one hole 1.21 in the rear wall 12 of the box 1. The holes 111, 121 are arranged in such a way that in one space between the deionization plates 13 the rear hole 121 in the rear wall 12. of the box j iS positioned further away from the side wall 11 in which there is the side hole 111 of the particular space. As regard the particular design and shape of the holes 111, 121 they all have a rectangular shape and the overall area of the side holes lil is smaller than the area of the rear holes 121 The function of the device is as follows. The electric arc resulting from disconnection of contacts of the circuit-breaker moves through the extinguishing chamber to the area of the deionization plates. Possible growth of gas overpressure in the extinguishing chamber that would prevent exit of the arc from these contacts is reduced by the exhaust of gases through the holes in the box of the extinguishing chamber while this gas exhaust is accelerated by creation of holes in the side walls and in the rear wall of the extinguishing chamber box at the same time and also by the fact that gases exiting the box of the extinguishing chamber laterally are routed through the side horizontal channels back to the area of contacts, where thanks to the speed that the gases have at this moment, they help to further accelerate exit of the electric arc from the contacts, which further reduces the switching-off time and increases the maximum short-circuit load of the circuit-breaker Usability in practice A device based on the invention can be mainly utilized in a current circuit-breaker, but similarly, the entire extinguishing chamber of the described type and arrangement can also be used in other devices with disconnecting contacts that should resist high short-circuit loads

Claims

1. An extinguishing chamber (10) for a current circuit-breaker (100) or other device having disconnecting contacts, the chamber comprising a box (1) for location next to disconnecting contacts, the box having pair of side walls (11) and a rear wall (12), deionization plates (13) made generally of ferromagnetic material being installed in the box perpendicularly to its walls, the walls of the box being formed with holes (111,112) designed to exhaust gases from the extinguishing chamber, the holes being divided into two groups (111, 121), the holes of the first group (111) being made in both the side walls of the box for connecting the area of the box via exhaust channels (101) with the area of the disconnecting contacts, and the holes of the second group (121) being made in the rear wall of the box with free exhaust outside the extinguishing chamber.

2. An extinguishing chamber according to claim 1, wherein the deionization plates (13) are made of ferromagnetic material.

3. An extinguishing chamber according to claim I or 2, wherein the deionization plates have a surface finish made of material that is resistant to high temperatures and oxidation.

4. An extinguishing chamber according to any of claims 1 to 3, wherein the deionization plates have a copper-plated surface finish.

5. An extinguishing chamber according to any of claims 1 to 4, wherein the deionization plates have angular cut-outs (131) in their front parts.

6. An extinguishing chamber according to claim 4, wherein the axes of the angles of the angular cut-outs are diverted alternately to one side and the other side from the longitudinal axis of the box.

7. An extinguishing chamber according to any of claims I to 6, wherein the holes in the box in the first group made in the side walls of the box are gradually positioned in individual spaces between the deionization plates, alternately in one side wall and the other side wall of the box.

8. An extinguishing chamber according to any of claims 1 to 7, wherein the holes in the box in the second group made in the rear wall of the box are positioned in individual spaces between the deionization plates, alternately nearer one side wall and the other sidewall.

9. An extinguishing chamber according to any of claims 1 to 8, wherein in each space between the deionization plates (13) there is just one of the side holes in a side wall and one rear hole in the rear wall of the box

10. An extinguishing chamber according to claim 9, wherein in each space between the deionization plates the rear hole in the rear wall of the box is positioned further away from the side wall in which there is the side hole of the particular space between the deionization plates.

ii. An extinguishing chamber according to any of claims ito 10, wherein the holes have a rectangular shape.

12. An extinguishing chamber according to any of claims Ito ii, wherein the total area of the side holes is smaller than the total area of the rear holes.

13. An extinguishing chamber substantially as described with reference to the drawings.

14. A current circuit-breaker or other device having disconnecting contacts, in combination with an extinguishing chamber as claimed in any preceding claim.