Collapsible Cone Element for Fire-Safe Ventilation Backflow Prevention
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Solution Overview
Problem
Existing backflow prevention devices in ventilation systems are complex, costly, and lack reliability in preventing the spread of hot and harmful substances during fires, with uncontrolled collapse of flexible materials affecting sealing quality.
Innovation Solution
A fire retarding backflow prevention device featuring a collapsible element shaped like a hollow cone, attached to the interior wall of the duct, which moves between a collapsed position for normal airflow and an expanded position to prevent backflow, using a thin, flexible, heat-resistant material with an airtight coating, and secured by simple structural elements to maintain low manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a flexible material is used to prevent backflow by collapsing against a web, then backflow prevention is achieved, but the device becomes complex with multiple components and the sealing quality is uncontrolled
Solution Approach 1:
The invention extracts and eliminates the web component from the system. The collapsible element is directly attached to the duct wall, removing the intermediate web that caused complexity. This simplifies the device structure while maintaining backflow prevention functionality through the direct attachment mechanism.
Solution Approach 2:
The invention merges the attachment function into the collapsible element itself by directly attaching it to the duct wall. This combines what were previously separate components (flexible material and mounting structure) into a unified system, reducing component count and simplifying the overall device architecture.
2Reliability
If a web is mounted as an abutment to allow flexible material collapse, then sealing is attempted, but the solution requires several different components to co-operate
Solution Approach 1:
The web component is completely removed from the system. The collapsible element achieves sealing by directly collapsing against the duct wall where it is attached, eliminating the need for a separate web abutment and reducing the component count from multiple parts to a single integrated element.
Solution Approach 2:
The collapsible element serves its own sealing function by directly attaching to the duct wall. It does not require a separate web component to provide the abutment surface, as it uses the duct wall itself for both attachment and sealing purposes, making the system self-sufficient with fewer components.
3Reliability
If the flexible material collapse is uncontrolled, then backflow prevention is achieved, but the sealing quality depends on the collapse manner
Solution Approach 1:
The collapsible element is pre-shaped with predetermined fold lines and attachment points during manufacturing. This preliminary structuring ensures that when collapse occurs during operation, it follows a controlled path along the pre-defined folds, achieving reliable sealing without depending on uncontrolled random collapse behavior.
Solution Approach 2:
The invention introduces specific geometric parameters including fold line positions, attachment point locations, and element dimensions that control the collapse behavior. By carefully selecting these parameters during design, the collapse process becomes predictable and controlled, ensuring consistent sealing quality across different installations.
4Loss of energy
If the collapsed element takes up a minor portion of air flow area, then pressure drop is kept low, but the element must be optimally positioned
Solution Approach 1:
The collapsible element is designed with an asymmetric configuration where the attachment point and fold lines are positioned to create an optimized collapse geometry. This asymmetric design ensures that when collapsed, the element occupies minimal cross-sectional area of the duct, reducing pressure drop while maintaining effective sealing when expanded.
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 device effectively prevents the spread of fire and smoke by maintaining a low pressure drop and ensuring efficient airflow, with a controlled collapse mechanism that reduces manufacturing costs and enhances backflow prevention, achieving reliable performance in both normal and fire scenarios.
Implementation Method 1
the collapsible element is moveable between a first collapsed position allowing air flow through the duct in a first direction, and a second expanded position preventing harmful substances to flow through the duct in an opposite direction
Data Source
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Figure 5
AI summary
A fire retarding backflow prevention device of a ventilation system has a hollow duct (30) and a collapsible element (50) which is arranged within the duct (30) and which is moveable between a first collapsed position allowing air flow through the duct (30) in a first direction and a second closed position preventing harmful substances to flow through the duct (30) in an opposite direction. The collapsible element (50) is attached to the interior wall of the duct (30) and extends along a longitudinal axis of the duct (30). In its closed expanded position, the collapsible element (50) forms a circular symmetric cone which is coaxial with the duct (30) and which has its apex (50A) on the longitudinal axis (C') thereof.