Fire Damper Strut Assembly for Tactile Reset in Tight Duct Access
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Solution Overview
Problem
Fire damper assemblies in air ducts face challenges during testing and resetting due to limited access and obstruction by adjacent pipes and cables, making visual inspection and manual actuation difficult, and there is a need for easier operability and tactile confirmation of proper reconnection post-testing.
Innovation Solution
A fire damper assembly with a collapsible strut supported by hanger arms, where one end is removably connected and can swing freely to allow the damper to move from an open to a closed position, and manual reconnection provides tactile confirmation of proper positioning without visual inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the access opening in the duct is kept small to avoid air leaks, then air tightness is improved, but access to the fusible strut and damper for testing and inspection becomes difficult
Solution Approach 1:
The fusible strut is designed as a separable assembly with a fusible link portion and a support arm portion that can be disconnected from each other. This segmentation allows the support arm to remain in place maintaining air tightness, while the fusible link can be removed and repositioned for testing purposes without requiring a large access opening.
Solution Approach 2:
The fusible link is extracted as a separate removable component from the support arm. The support arm remains permanently installed to maintain air tightness and structural support, while the fusible link can be taken out through the small access opening, repositioned to allow damper movement, and reinstalled after testing.
2Adaptability or versatility
If pipes, ducts, cables and other components are placed adjacent to or within the air duct, then system functionality is improved, but visual inspection and manual actuation of the damper assembly are hampered
Solution Approach 1:
The support arm acts as an intermediary component that remains in the confined space within the duct while the fusible link operates externally. The support arm transmits the mechanical action from the fusible link to the damper, allowing the operator to work from outside the duct through a small access opening without needing visual access to the damper itself.
Solution Approach 2:
The direct visual-line-of-sight mechanical operation is replaced with a indirect mechanical linkage system. Instead of requiring direct visual access and manual manipulation of the damper, the system uses the support arm as a mechanical extension that translates external manipulation of the fusible link into internal damper actuation.
3Stability of the object's composition
If the fusible strut is made permanently connected to the frame, then structural stability is improved, but testing and resetting of the damper becomes difficult
Solution Approach 1:
The fusible strut is divided into two separable segments: the support arm that remains permanently connected to the frame for structural stability, and the fusible link that can be removed and repositioned for testing. This segmentation maintains structural integrity while enabling periodic testing and resetting.
Solution Approach 2:
The fusible link is designed to be temporarily removed (discarded from its normal position) during testing, allowing the damper to be actuated, and then recovered (reinstalled) in its original position after testing. This temporary discarding and recovery enables maintenance while preserving the permanent structural connection of the support arm.
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
Facilitates easier testing and resetting of fire damper assemblies by allowing manual operation and tactile confirmation of proper reconnection, overcoming access limitations and obstructions within the air duct.
Implementation Method 1
one or more fusible links which are joined by a eutectic substance which liquefies at a predetermined temperature
Implementation Method 2
movable from a normal, open or retracted position in which the flow of air through the duct is unimpeded to an extended, closed position in response to an increase in ambient temperature
Data Source
AI summary
A fire damper assembly has a damper mounted in an air duct for movements between an open, air passing position in which the damper enables air to flow through the duct and a closed position in which the damper blocks the passage of air through the duct. A strut composed of joined but separable components normally underlies the damper and supports the latter in the open position. The strut may be moved from its damper engaging position to a damper-free position while the separable components remain joined. At least one end of the strut is pivotally connected to a support arm for swinging movements of the strut between damper engaging and damper-free positions and may have its opposite end manually detached from the second support arm, thereby enabling the damper to swing to its closed position. The respective support arms are removably maintained in strut-supporting position by releasable latches which enable a tactile sensing of their positions.