Double-Wall Ventilation Pipe Assembly With Fire-Resistant Foam

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Solution Overview

Problem

Existing ventilation pipeline systems made of sheet metal lack effective fire protection and soundproofing, leading to potential fire spread and noise transmission, and existing solutions either deform in fires or compromise on aesthetics and hygiene.

Innovation Solution

A pipeline arrangement with an inner and outer pipe forming an intermediate space filled with a fire-resistant, thermally insulating inorganic foam that can be cured on-site, providing dimensional stability, improved soundproofing, and reduced flow resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sheet metal pipelines are used for ventilation, then the pipelines are mechanically stable and easy to manufacture, but they lack fire protection properties and deform in the event of fire

Engineering Contradiction:
Improvefire protection propertiesVSAvoidresistance to fire deformation
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies composite materials by combining sheet metal pipelines with fire protection compounds (intumescent coatings, fire-resistant insulation layers, or cementitious materials). This creates a composite structure where the metal provides mechanical strength and the fire protection compound provides thermal insulation and fire resistance, preventing deformation during fire exposure while maintaining the original pipeline's structural integrity.

Inventive Principle:
Principle #40Composite materials

2Reliability

If fire protection panels are used to cover existing pipelines, then fire protection is improved, but soundproofing properties deteriorate and aesthetic appearance is compromised

Engineering Contradiction:
Improvefire protectionVSAvoidnoise transmission
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by selecting fire protection compounds with specific dual properties: intumescent coatings that provide fire resistance while maintaining surface smoothness for sound transmission, or fire-resistant insulation materials with acoustic absorption capabilities. This allows different regions or layers of the fire protection system to address both fire safety and noise reduction requirements simultaneously.

Inventive Principle:
Principle #3Local quality

3Reliability

If non-combustible fire protection panels are used, then fire resistance is improved, but dust abrasion occurs due to gas flow and hygiene is compromised

Engineering Contradiction:
Improvefire resistanceVSAvoiddust abrasion
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by modifying the surface properties of fire protection materials to reduce dust generation. This includes using intumescent coatings that form smooth, glass-like surfaces after fire exposure, selecting fire-resistant cementitious materials with fine aggregate compositions that minimize particle detachment, or applying protective sealant layers that prevent material abrasion from high-velocity gas flow while maintaining fire resistance ratings.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If mineral wool is used to cover pipelines for fire protection, then fire protection is improved, but aesthetic appearance and soundproofing are worsened

Engineering Contradiction:
Improvefire protectionVSAvoidaesthetic appearance
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies the nested doll principle by creating a multi-layered fire protection system where mineral wool or fire-resistant insulation is nested within a smooth outer casing or coating. This nested structure allows the inner insulation layer to provide fire protection while the outer layer maintains aesthetic appearance and can be integrated with the pipeline's visual design, eliminating the need for visible welding pins or rough surfaces.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 prevents fire spread and noise transmission while ensuring dimensional stability, hygiene, and aesthetic appeal, meeting modern fire protection standards and reducing energy losses.

Implementation Method 1

filled with a fire-resistant, thermally insulating inorganic foam

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

inorganic foam that can be cured on-site, providing dimensional stability

Methodology Applied
Scientific EffectChemical curing:

Implementation Method 3

prevents fire spread and noise transmission while ensuring dimensional stability

Methodology Applied
Scientific EffectThermal barrier: Thermal Insulation

Data Source

PatentEP2722572B1Pipework assembly, in particular for use in the field of ventilation technology
Publication Date: 2017.04.26 PROMAT GMBH(DE)
  • EP2722572B1 patent drawingFigure 1~1B
  • EP2722572B1 patent drawingFigure 2~2B
  • EP2722572B1 patent drawingFigure 3

AI summary

The arrangement has an inner pipe (2) arranged in an outer pipe (3) to form a gap (4) i.e. annular gap, where the gap is filled with fire protection compound. The fire protection compound comprises a partially flame retardant. The compound mixed with water is filled in the gap and cured to form a fire protection foam. The inner and outer pipes are made of a non-combustible material such as sheet metal, and arranged concentrically to one another, where wall thickness of the outer pipe is about 0.01-10 mm, preferably about 0.8-3 mm.