Fire Damper Flap Pivot Axis Sealing Gap
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fire dampers with pivot axes of large diameters face reduced insulating effectiveness due to less material being available for sealing around the pivot axis, leading to compromised sealing and potential fire and smoke leakage.
Innovation Solution
The shut-off flap in the region of the pivot axis features protruding regions that extend laterally over the circumference, traversed by the pivot axis, which narrows the movement gap between the flap and the heat-expanding material, compensating for the reduced material and enhancing the sealing effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a passage for the pivot axis is provided in the housing and material, then the pivot axis can be mounted for rotation, but the insulating effect is reduced in the area of the pivot axis due to less material being provided
Solution Approach 1:
The shut-off flap is given a different local structure in the region of the pivot axis compared to other areas. Specifically, the flap has a reduced thickness or includes a recess in the pivot axis region, creating less material between the outer edge of the butterfly valve and the inner surface of the housing. This local modification allows the pivot axis to rotate more freely while maintaining adequate sealing in other critical areas where the full thickness of the flap is preserved.
2Reliability
If the material that expands when exposed to heat is provided around the pivot axis, then sealing can be achieved, but the movement gap remains too wide due to the passage required for the pivot axis
Solution Approach 1:
The patent modifies the geometric parameters of the shut-off flap in the pivot axis region. By reducing the thickness of the flap or creating a recess, the parameters are changed locally to allow the pivot axis to pass through with minimal interference. This parameter modification enables the intumescent material to expand and seal the gap effectively, as there is less material in the way of the expanding material's path to the gap.
3Ease of manufacture
If the shut-off flap has uniform thickness, then manufacturing is simplified, but the sealing effect is compromised in areas with large diameter pivot axes
Solution Approach 1:
The shut-off flap transitions from uniform thickness to non-uniform thickness with a specific local modification in the pivot axis region. The flap has reduced thickness or includes a recess where the pivot axis passes through, creating adequate space for the intumescent material to expand and seal effectively. This local quality change prioritizes sealing reliability in the critical pivot axis region while maintaining manufacturability through a relatively simple geometric modification.
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 significantly narrows the movement gap around the pivot axis, improving the sealing efficiency and enhancing the protective function of fire dampers by maintaining a tighter seal even in areas with larger pivot axes.
Implementation Method 1
a material that expands when exposed to heat, the partial area being provided along the circumference of the shut-off flap
Implementation Method 2
The intumescent material, which expands under heat, is arranged on the inside of the housing in the effective area with the butterfly valve in the closed position
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The damper has housing for a shut-off valve (3), which is rotatably supported on a rotational axis. The shut-off valve includes an area (9), which projects into a gap (7), and radially extends over a circumference laterally within an area of the rotational axis, in such a manner that the movement gap between the shut-off valve and a material is clearly small than in other areas, within the area of the rotational axis.