Fire Collar Torsion Spring Closure for Cable Penetration Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fire collars are ineffective in preventing the spread of flames, hot air, and smoke through penetrations in walls containing clusters of plastic-coated copper wires, as the intumescent material fails to closely envelop the wires, leaving gaps that allow heat, smoke, and gases to pass through.
Innovation Solution
A fire collar design featuring a body with an open-ended passage, mounting means, a layer of intumescent material, a protective layer, retaining means, and actuation via torsion springs that form a ligature around services, with spring forces strong enough to push apart the outer layer of wires and embed deeper, ensuring the intumescent material fully encloses the passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fire collar uses a simple cylindrical enclosure with intumescent material, then it is easy to manufacture and install, but it fails to closely envelop clusters of plastic-coated copper wires, leaving gaps that allow heat and smoke to pass through
Solution Approach 1:
The fire collar incorporates a collapsible cage structure that transitions from an expanded installation state to a compressed fire-containing state. The cage includes radially extendable elements that can be collapsed inward using compression members (springs or cam mechanisms) when activated by heat or manual operation, allowing the intumescent material to be compressed against the wires and form a tight seal around irregularly shaped cable clusters.
Solution Approach 2:
The cage is divided into multiple radial segments or elements that can independently collapse inward. This segmentation allows the structure to adapt to the irregular shape of wire clusters while maintaining the ability to compress the intumescent material uniformly around all wires, ensuring complete envelopment without gaps.
2Ease of operation
If the intumescent material is placed loosely within the cylindrical enclosure, then it is easy to install, but it does not maintain close contact with the wires during expansion, allowing gaps to form
Solution Approach 1:
The collapsible cage structure dynamically transitions from an expanded state during installation to a compressed state during fire events. This dynamic compression maintains continuous contact between the intumescent material and the wire cluster, ensuring that when the material expands, it is constrained against the wires and cannot form gaps, while still allowing for easy initial installation.
Solution Approach 2:
The cage is pre-configured in an expanded state that allows easy installation around wire clusters without requiring complex assembly. The compression mechanism is pre-loaded but not activated during installation, allowing the intumescent material to be positioned loosely initially. Upon activation by heat or manual operation, the compression is applied to secure the material against the wires before expansion occurs.
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 effectively prevents the spread of flames, hot air, and smoke by ensuring the intumescent material forms a solid plug around the services, even when encountering plastic-coated copper wires, by applying sufficient force to push the material into close contact and maintain it as it expands, thus blocking heat and gas passage.
Implementation Method 1
As the temperature of the ambient air increases, the intumescent material will then expand so as to fully close both the bore and the pipe, and shall form a thick solid plug that is contained within the bore and which also surrounds the deformed section of the pipe that is contained within the fire collar
Implementation Method 2
actuation means, such as three or more torsion springs that are each located in a respective housing. Each torsion spring includes two elongate, substantially straight, tails and whereby one tail, hereinafter referred to as the actuating tail, of each spring in use is capable of moving from a non-operating mode proximal to the layer of intumescent material to an operating mode in which it extends partially across the bore
Data Source
AI summary
This invention relates to a fire collar (10). The fire collar includes a body (11) that is constructed from a flexible, elongate strip of steel (12) having a first end portion (13) associated with one end thereof and an opposing second end portion (14) associated with the opposite end thereof. The fire collar (10) also includes actuation means, including a plurality of torsion springs (28) manufactured from spring steel, such as spring steel having a diameter of 4 mm or 5 mm. Each torsion spring (28) includes a spring body (29) comprising one or more helical coils, and two tails, (30) and (31), that extend outwardly away from opposite ends of the body.