Fire-Protected Channel Seal Design

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Solution Overview

Problem

Existing fire protection ducts require complex installation and can damage intumescent material when connecting sections are inserted, leading to reduced inner duct volume and increased installation effort, while also necessitating additional connectors for sealing and electrical contact.

Innovation Solution

A butt seal design for fire protection ducts that uses internal side and base parts with sealing material, leveraging existing cover connection rails to create a tool-free, connector-free seal that maintains electrical contact and cold smoke tightness without damaging the intumescent material, allowing for face-to-face mounting of ducts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If connecting sections are inserted into fire protection ducts, then duct sections can be joined together, but the intumescent material layer is damaged

Engineering Contradiction:
Improveduct connectionVSAvoidintumescent material integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The connection system is divided into separate components: a connecting section without intumescent material and the main duct sections with intumescent material. This segmentation allows the connecting section to be inserted without damaging the intumescent material layer on the duct sections, while still providing effective fire protection through the combination of metal and intumescent materials.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A connecting section acts as an intermediary element between two duct sections. This connecting section is specifically designed without intumescent material coating, allowing it to be inserted into the duct without damaging the intumescent material layer. The connecting section provides mechanical connection while the duct sections provide fire protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If hat-shaped metal connectors are used to seal duct joints, then cold smoke tightness is achieved, but installation effort increases due to drilling holes and positioning requirements

Engineering Contradiction:
Improvecold smoke tightnessVSAvoidinstallation effort
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The sealing function and connection function are merged into a single integrated sealing element. This sealing element combines the sealing features with the connection mechanism, eliminating the need for separate hat-shaped connectors and reducing installation steps. The sealing element is designed to be positioned and fixed without requiring additional drilling or complex positioning operations.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If fire protection ducts are lined with fire-retardant materials like rock wool or plasterboard, then fire protection effect is improved, but duct volume for cable laying is reduced

Engineering Contradiction:
Improvefire protection effectVSAvoidduct volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The fire protection duct uses a composite structure combining metal duct sections with intumescent material coating. This composite material approach provides effective fire protection through the intumescent material's expansion properties when exposed to fire, while maintaining the duct's internal volume for cable laying, unlike bulk materials like rock wool or plasterboard that would significantly reduce the usable space.

Inventive Principle:
Principle #40Composite materials

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

Simplifies the connection of fire protection ducts by eliminating the need for additional connectors and tools, ensuring effective sealing and electrical contact while preserving the intumescent material's integrity and maintaining cold smoke tightness even with misaligned ducts.

Implementation Method 1

Intumescent material has the property of expanding under the influence of heat. When exposed to heat, this material swells up in the area affected by the heat and fills the duct volume, so that a fire-prevention barrier is then provided in the event of a cable fire.

Methodology Applied
Scientific EffectIntumescent material expansion: Intumescent Materials

Implementation Method 2

These connectors are coated on the inside with a sealing material, for example a foam or fleece, which overlaps the joint and acts through the metal connector under a certain prestress against the areas of the two fire protection ducts delimiting the joint gap.

Methodology Applied
Scientific EffectPrestress:

Data Source

PatentEP3467977B1Fire-protected channel seal and line-guiding channel arrangement designed as fire protected channel
Publication Date: 2020.07.08 OBO BETTERMANN PRODUKTION DEUTSCHLAND GMBH & CO KG (100 00)
  • EP3467977B1 patent drawingFigure 1
  • EP3467977B1 patent drawingFigure 2~3
  • EP3467977B1 patent drawingFigure 4

AI summary

Described is a fire-resistant duct joint seal for sealing the gap between the opposing joints of two fire-resistant ducts intended for cable routing. Each fire-resistant duct has a base, two integrally formed side walls following the longitudinal extent of the duct, each with a cover connection rail, and a cover that can be fastened in the cover connection rails. The base and side walls are equipped on the inside with a layer of intumescent material. The joint seal is designed as an internal seal. The joint cover comprises these two side parts, a base part, and a cover part, each of which carries a sealing material on its outer surface extending over the joint gap.which side parts have on their longitudinal side facing away from the bottom of the fire protection duct a fitting for contacting the outside of an intumescent material-free wall of a cover connection rail and in the area of ​​their bottom-side longitudinal side at least one locking tab projecting towards the inside of the duct, and a non-projecting section of the side parts extends beyond the termination of the at least one locking tab facing the bottom of the fire protection duct and forms a contact for the longitudinal end faces of the bottom part mounted between the side parts, which bottom part engages the at least one locking tab of each side part and is supported on the contacts of the side parts, and which cover part has a cover plate extending over the width of the cover-side opening of the fire protection duct.which can be supported by at least one bearing extension on an upper end face of the cover connection rails and has two hook elements projecting transversely to the fire protection duct extension for engaging the cover connection rails of the side walls. Also described is a service duct arrangement designed as a fire protection duct with such a butt seal.