Fire-Rated Duct Access Door with Composite Panel and Intumescent Seal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inspection hatches for ducts lack fireproof insulation, allowing fires to spread quickly between the inside and outside of the duct, posing a safety risk and potential for fire to spread through buildings.
Innovation Solution
A fireproof inspection hatch is designed with a composite material panel, such as a cement matrix with calcium silicate reinforcement, fixed to the duct using removable fastening means made of the same material, and incorporating an intumescent seal to enhance thermal insulation and prevent heat transfer, ensuring a barrier against fires up to 1200°C for up to 120 minutes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a metal inspection hatch is used to allow access to the duct, then ease of operation is improved, but fire resistance deteriorates as metal walls cannot provide fireproof insulation
Solution Approach 1:
The patent applies composite materials by combining a metal frame structure with fire-resistant panels (such as cement board, gypsum board, or intumescent panels) to create an inspection hatch that provides both mechanical strength and fire resistance. The composite construction allows the hatch to maintain structural integrity while providing fireproof insulation for up to 120 minutes.
Solution Approach 2:
The patent changes the material parameters of the hatch components by specifying fire-resistant materials with specific thermal insulation properties and fire ratings. The use of intumescent materials that expand when exposed to heat further modifies the physical parameters to enhance fire resistance while maintaining operational functionality.
2Reliability
If fire-resistant composite panels are used to ensure fireproof insulation, then fire resistance is improved, but device complexity increases due to multiple components and assembly requirements
Solution Approach 1:
The patent segments the inspection hatch into distinct functional components: a metal frame structure, fire-resistant panels, sealing elements, and fastening mechanisms. This segmentation allows each component to be optimized independently for its specific function while simplifying the overall assembly process through modular construction.
Solution Approach 2:
The patent introduces intermediary elements such as thermal insulation layers, sealing gaskets, and mounting brackets that facilitate the integration of fire-resistant panels with the metal frame. These intermediary components simplify the assembly process by providing standardized interfaces and ensuring proper fit between different materials.
3Ease of operation
If removable fastening means are used to allow hatch removal for inspection, then ease of operation is improved, but fire resistance deteriorates as fastening components may create thermal bridges
Solution Approach 1:
The patent employs flexible thermal insulation materials and thin fire-resistant film coatings on the fastening components to eliminate thermal bridges. The removable fasteners are designed with thermal breaks or insulation layers that prevent heat transfer through the fastening points, maintaining fire resistance while allowing easy removal for inspection.
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 solution effectively maintains a fire barrier between the inside and outside of the duct, preventing rapid fire spread and protecting ducts with conduits like air ducts and cable ducts from fire incidents, ensuring safety and allowing for inspection and maintenance while maintaining fireproof properties.
Implementation Method 1
the hatch includes an intumescent seal. Thus, in the event of a fire, the joint sees its volume swell and the thermal insulation is reinforced
Implementation Method 2
By fireproof panel is meant in particular a panel capable of maintaining, for a period of up to 120 minutes, a barrier to fire during a fire whose temperature rises to 1200°C
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention is a fire-rated access door (10) for a duct (8). The door comprises at least one fire-rated panel (26) comprising a layer of composite material, the door comprising a blocking wall (14), the panel being fixed to the wall by means for removable attachment, for example by at least one screw assembly (18, 20, 22, 23, 28), the means for removable attachment preferably comprising the same material as the panel (26).