Arc Extinguishing Chamber Balancing Wall Gas Flow Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Re-breakdown phenomena in miniature circuit breakers occur due to poor gas circulation control, leading to degraded arc insertion and quality of cut, often exacerbated by the melting of insulating grids used to prevent arc re-establishment downstream of the extinguishing chamber.

Innovation Solution

An interrupting chamber design with a balancing partition that rebalances gas circulation by limiting flow in areas where it is excessive and redirecting it to areas where it is insufficient, eliminating the need for a close-proximity insulating grid, which melts and obstructs gas flow, and incorporating a reduced number of cooling elements inclined relative to the base to maintain fins and control arc insertion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an insulating grid is placed downstream of the arc extinguishing chamber to prevent arc re-establishment, then arc insertion quality is improved, but the grid melts during switching off which obstructs gas circulation and degrades performance

Engineering Contradiction:
Improvearc insertion qualityVSAvoidgas flow obstruction
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent removes the insulating grid component entirely from the system. Instead of placing a grid downstream of the arc extinguishing chamber, the invention uses the inclined wall structure to directly control gas circulation and prevent arc re-establishment, eliminating the harmful melting and obstruction effects of the grid

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an inclined wall as an intermediary structure between the arc extinguishing chamber and the downstream region. This wall mediates gas circulation by redirecting hot gases through specific paths, achieving both arc insertion control and maintaining gas flow without requiring a separate insulating grid

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If gas circulation is allowed to follow the most direct path from the contact zone, then gas evacuation is efficient, but arc insertion becomes unbalanced and re-breakdown phenomena occur

Engineering Contradiction:
Improvegas evacuation efficiencyVSAvoidarc insertion balance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent employs an asymmetric inclined wall structure that creates different gas circulation paths on either side of the chamber. The wall is positioned at an angle between 5-15 degrees, which asymmetrically redirects gas flow to ensure balanced arc insertion across all fins while maintaining efficient evacuation through the inclined path

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent applies local quality control by positioning the inclined wall to specifically affect gas circulation in certain regions of the chamber. The wall redirects gases to reach fins that would otherwise be underserved, creating locally optimized gas distribution patterns that ensure uniform arc insertion across the entire chamber

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design enhances the quality of the cut, reduces re-breakdown risks, and improves energy capacity by maintaining arc voltage control, eliminating the need for additional components, thus reducing costs and improving device robustness.

Implementation Method 1

rebalance the circulation of the gases, by limiting the circulation in certain places where it was satisfactory in favor of another place where it was insufficient

Methodology Applied
Scientific EffectGas circulation: Convection

Implementation Method 2

a block formed by all of these cooling elements

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 3

an arc formation chamber containing a fixed contact and a movable contact, which, at the time of their separation, form an arc between them

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2804189B1Arc extinguising chamber for an electric protection apparatus and electric protection apparatus comprising same
Publication Date: 2018.03.07 SCHNEIDER ELECTRIC IND SAS
  • EP2804189B1 patent drawingFigure 1~2
  • EP2804189B1 patent drawingFigure 3~4
  • EP2804189B1 patent drawingFigure 5~8

AI summary

The present invention relates to a breaking chamber (7) of an electrical protection device comprising an arc forming chamber containing a fixed contact (4) and a moving contact (3), which, at the moment of their separation, form an arc (a) between them, said arc forming chamber communicating with the inlet of a second chamber called arc extinction chamber. This chamber is characterized in that it comprises a so-called balancing wall (14), substantially solid over at least its central part, said wall being located downstream of the arc extinguishing chamber (9) and being shaped and arranged with respect to the arc extinguishing chamber (9), so as to slow down the exhaust flow of the cut-off gases on the side i of the extinguishing chamber (9) where the gases go first and to favor the flow of the exhaust gases on the opposite side j, said exhaust gases being stopped by the central part of the wall (14) and escaping through the edges of the wall (14).