Polyurethane Foam Insulation for Pipe Centering

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Solution Overview

Problem

Insulated pipes produced using the lance method often suffer from insufficient compressive strength and poor centering of the steel pipe, failing to meet the requirements of EN 253:2003 standards.

Innovation Solution

Incorporating glycine, N-((2-hydroxy-5-nonylphenyl)methyl)-N-methyl monosodium salt into the polyurethane foam, along with other catalysts, to influence the rising time and hardening of the foam, ensuring it can support the pipe and maintain centering effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the lance method is used to produce insulated pipes, then the production process is simplified and continuous, but the compressive strength of the polyurethane foam is insufficient

Engineering Contradiction:
Improveproduction process simplicityVSAvoidcompressive strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent modifies the chemical composition parameters of the polyurethane foam by incorporating specific catalysts (ammonium salts, amine compounds) and blowing agents (water, carbon dioxide, hydrocarbons) in controlled amounts. This changes the foam's physical-chemical parameters to achieve both continuous production capability and sufficient compressive strength (>0.3 N/mm²) to support the pipe structure.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite polyurethane foam system combining multiple components: polyol mixture, isocyanate component, catalysts (ammonium salts, amine compounds), and blowing agents (water, CO2, hydrocarbons). This composite material approach enables the foam to achieve both ease of continuous manufacture and the required mechanical strength through synergistic material properties.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If the lance method is used to produce insulated pipes, then the production process is simplified, but the centering of the steel pipe is poor

Engineering Contradiction:
Improveproduction process simplicityVSAvoidpipe centering
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent adjusts the foaming kinetics parameters by selecting specific catalysts and blowing agents to control the expansion rate and timing of the polyurethane foam. This enables the foam to rise uniformly around the steel pipe, providing continuous radial support that maintains precise centering while allowing simplified continuous production.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs self-regulating foaming characteristics where the reaction exotherm and foam expansion are automatically controlled by the chemical composition. The foam rises and expands in response to the reaction heat and pressure differential, providing self-centering effect without external mechanical guidance, thus achieving both simplicity and precision.

Inventive Principle:
Principle #23Feedback

3Strength

If the polyurethane foam rises quickly to support the pipe, then the pipe is prevented from sagging, but the foam hardening time is reduced

Engineering Contradiction:
Improvesupport capabilityVSAvoidhardening time
Core Design Contradiction:
StrengthVSDuration of action of stationary object

Solution Approach 1:

The patent modifies the reaction kinetics parameters by incorporating catalysts (ammonium salts, amine compounds) that accelerate the polyurethane formation reaction. This enables the foam to rise quickly and achieve sufficient strength (>0.3 N/mm²) to support the pipe before sagging occurs, while the controlled catalyst amount ensures complete hardening within acceptable time frames.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent prepares the reaction mixture with pre-measured catalysts and blowing agents that will activate upon contact with the steel pipe surface. This preliminary preparation ensures the foam begins rising and hardening immediately upon injection, achieving support capability quickly while the controlled reaction progression ensures complete hardening is achieved.

Inventive Principle:
Principle #10Preliminary action

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 modified polyurethane foam achieves compressive strengths greater than 0.3 N/mm² and improved centering, meeting the EN 253:2003 standards by quickening the foam's hardening and supporting capabilities.

Implementation Method 1

the polyurethane foam contains glycine, N-((2-hydroxy-5-nonylphenyl)methyl)-N-methyl monosodium salt (CAS number 56968-08-2)... By using this catalyst according to the invention, the rising time and the hardening of the foam can be influenced as desired

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

producing a polyurethane foam by reacting an isocyanate component (a) with a polyol mixture (b) between the medium pipe and the casing pipe

Methodology Applied
Scientific EffectPolyaddition reaction: Chemical Bonding

Implementation Method 3

the liquid reaction mixture is then filled into the annular gap using a polyurethane metering machine, which flows down the pipe gap in liquid form until the reaction begins. From this point on, further distribution takes place by flowing the foam, which slowly increases in viscosity

Methodology Applied
Scientific EffectGas generation and pressure differential: Pressure Gradient

Data Source

PatentEP1777242B1Polyurethane foams for insulating pipes
Publication Date: 2008.07.23 BASF SE
  • EP1777242B1 patent drawingFigure 1

AI summary

Insulated pipe comprises medium pipe, polyurethane-foam material containing glycine and N-((2-hydroxy-5-nonylphenyl)methyl)-N-methyl-mono sodium salt (CAS number 56968-08-2) and jacket pipe; where the polyurethane-foam material in present between the medium pipe and jacket pipe. An independent claim is included for a procedure for the production of insulated pipes, comprising providing the medium pipe and jacket pipe, where the medium pipe is arranged within the jacket pipe; and producing polyurethane-foam material by reacting an isocyanate component with a polyol mixture between medium pipe and jacket pipe, where the glycine and N-((2-hydroxy-nonylphenyl)methyl)-N-methyl monosodium salt are mixed with isocyanate component and/or the polyol mixture before the reaction of isocyanate component with the polyol mixture.