Insulated Pipe Foaming with Adjustable End Caps
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Solution Overview
Problem
Existing methods for producing insulated pipes face challenges in achieving low and evenly distributed core bulk density, small cell diameters, and high compressive strength while minimizing thermal conductivity, and struggle with controlling pressure conditions during polyurethane system filling.
Innovation Solution
A method involving the use of size-adjustable caps for the ends of the annular gap between the medium and jacket pipes, allowing for continuous adjustment of opening sizes during filling, and employing a polyurethane system with specific viscosity and catalysts to achieve optimal foam distribution and properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If polyurethane foam is filled into the annular gap to achieve good insulating properties, then thermal insulation is improved, but controlling pressure conditions during filling becomes difficult
Solution Approach 1:
The cap is designed with adjustable openings that can be dynamically modified during the filling process. This allows the pressure conditions to be adapted in real-time as the polyurethane system is introduced, enabling better control over the foaming process while maintaining good thermal insulation properties.
Solution Approach 2:
The opening size of the cap can be varied during filling to change the pressure parameters. By adjusting the opening size, the pressure conditions inside the annular gap can be optimized for different stages of the filling and foaming process, resolving the contradiction between achieving good insulation and controlling pressure.
2Strength
If a high volumetric weight of polyurethane foam is used to achieve good compressive strength, then strength is improved, but thermal conductivity increases
Solution Approach 1:
By adjusting the opening size of the cap during the filling process, the pressure conditions can be optimized to achieve the desired bulk density without excessively increasing the volumetric weight. This allows for a balance between compressive strength and thermal conductivity by controlling the foam expansion and cell structure through pressure parameter adjustments.
3Productivity
If longer individual tube segments are manufactured to reduce socket connections, then productivity is improved, but manufacturing precision requirements increase
Solution Approach 1:
The adjustable cap allows for dynamic pressure control during the foaming process of longer pipe segments. This enables consistent quality and proper foam distribution even in longer segments where pressure equilibrium is more challenging to maintain, thereby supporting increased productivity without sacrificing manufacturing precision.
4Device complexity
If static ventilation holes are used in end caps, then device complexity is reduced, but ability to control pressure conditions during filling is limited
Solution Approach 1:
The cap transitions from a static design with fixed ventilation holes to a dynamic design where the opening size can be adjusted during the filling process. This provides operational flexibility to control pressure conditions at different stages of filling, improving ease of operation while maintaining reasonable device complexity.
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
This method results in insulated pipes with low thermal conductivity, high compressive strength, and uniform bulk density, enabling faster and higher-quality production while allowing for control of pressure conditions during filling.
Implementation Method 1
a polyurethane system containing an isocyanate component and a polyol component with a particularly low viscosity of less than 1300 mPas is filled into the annular gap between the medium pipe and the jacket pipe
Implementation Method 2
the liquid reaction mixture is then introduced into the annular gap by means of a polyurethane metering machine and flows down the tube gap in liquid form until the reaction begins. From this point on, further distribution takes place through the flow of the foam
Implementation Method 3
This annular gap is filled with polyurethane foam, as this has excellent insulating properties
Data Source
AI summary
The present invention relates to a method for manufacturing insulated pipes, comprising the steps of (A) provisioning a service pipe and a jacket pipe, wherein the service pipe is arranged within the jacket pipe, and an annular gap with ends E1 and E2 is formed between the service pipe and the jacket pipe; (B) introducing a polyurethane system comprising at least one isocyanate component (a) and at least one polyol mixture (b) at end E1 of the annular gap; and (C) the foaming and curing of the polyurethane system, wherein the annular gap is closed at end E2 by a cap, said cap having openings adjustable in size; a cap having openings that are adjustable in size; the use of this cap for the production of insulated pipes; and an insulated pipe, which can be manufactured by the method according to the invention as described above.