Fire Damper Pendulum Closure for Flush Duct Sealing

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Solution Overview

Problem

Existing fire dampers do not reliably seal ventilation ducts during a fire, allowing fire gases to escape due to incomplete closure of the drop flap.

Innovation Solution

A fire damper design featuring a closure element mounted in a pendulum motion guide system, which ensures the closure element fits flush with the ventilation duct opening by applying a force component that presses it against the duct wall, and includes a drive element like a tension spring to facilitate this sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a drop flap is used to close the ventilation duct, then the duct can be closed in the event of a fire, but the drop flap does not fit completely flush with the duct opening, allowing fire gases to escape

Engineering Contradiction:
Improvesealing reliabilityVSAvoidfitting precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The closure element is mounted in a pendulum motion guide system, allowing it to dynamically adjust its position and angle as it moves from the open to the closed state. This dynamic mounting enables the closure element to achieve complete flush contact with the duct opening, resolving the fitting precision issue while maintaining sealing reliability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The guide system changes the motion parameters of the closure element from simple vertical dropping to a controlled pendulum arc motion. This parameter change ensures the closure element approaches the opening at an optimized trajectory, guaranteeing complete coverage and flush contact for reliable sealing

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If the closure element is held above the ventilation duct by a fusible link, then the air flow path remains open during normal operation, but the closure element does not reliably seal the duct when released

Engineering Contradiction:
Improveautomatic release functionVSAvoidsealing reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The closure element transitions from a static holding position to a dynamic pendulum motion when released. This dynamic motion ensures the element reliably covers the entire opening and maintains flush contact, overcoming the sealing failures of previous static drop flap designs

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The pendulum motion guide system acts as an intermediary mechanism between the holding element and the closure element. It controls and guides the closure element's movement, ensuring it achieves the correct position and angle for reliable sealing, thereby mediating between the release mechanism and the sealing function

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The design achieves a tight seal in the closed position, meeting fire resistance and smoke tightness standards by ensuring the closure element fully covers the duct opening, effectively containing fire gases.

Implementation Method 1

the closure element is mounted in a pendulum motion in the guide system

Methodology Applied
Scientific EffectPendulum motion: Pendulum

Implementation Method 2

the closure element can be brought into an open position and a closed position

Methodology Applied
Scientific EffectGravitation: Gravitation

Implementation Method 3

a drive element and a holding element, wherein the closure element can be brought into an open position and a closed position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4056238B1Fire damper for an air duct through which air flows
Publication Date: 2025.10.15 ZLT LUFTUNGS UND BRANDSCHUTZTECHN
  • EP4056238B1 patent drawingFigure 1
  • EP4056238B1 patent drawingFigure 2a~2d
  • EP4056238B1 patent drawingFigure 3a~3c

AI summary

The invention relates to a fire damper for a flow-through air duct, comprising a passage opening, a closing element, a guide system, an actuating element, and a retaining element, wherein the closing element can be moved into an open position and a closed position. The object of the invention is to provide a fire damper for a ventilation duct which reliably closes the ventilation duct with a closing element in the event of a fire. The closing action should meet the requirements of the relevant standards in a fire resistance test, in particular, according to EN 1366-2, separation of the air passage, insulating effect, and smoke tightness.This problem is solved by mounting the locking element (3) pivotally in the guide system (4), such that a cross-sectional plane (17) of the locking element (3) can be tilted relative to a cross-sectional plane (18) of the passage opening (2) before it assumes the closed position, and by designing the guide system (4) such that, in the closed position of the locking element (3), a force component of the locking force presses a surface (3a) of the locking element (3) facing the first wall element (7) fully along the passage opening (2) against a surface (7a) of the first wall element (7) facing the locking element (3). (Fig. 2c).