3D-Printed Heat Exchanger Header for Leak-Free Tube Assembly

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Solution Overview

Problem

Current manufacturing methods for heat exchanger headers are labor-intensive and prone to leaks, limiting material choices to metals with similar melting points and restricting the use of non-metallic materials.

Innovation Solution

Utilizing additive manufacturing to build headers in-situ on stacked tubes, allowing for multi-material construction and leak-free joints by encapsulating tubes as they are stacked, or pre-forming and laminating header parts for faster assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional welding or brazing is used to join header and tubes, then joints can be made, but the process is labor intensive and leak prone

Engineering Contradiction:
Improvejoint leak-freeVSAvoidmanufacturing labor intensity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces traditional mechanical joining methods (welding, brazing) with an additive manufacturing process that deposits material to form headers directly around tube ends. This substitution eliminates the need for separate joining operations, reducing labor intensity and improving joint reliability by creating monolithic, leak-free connections through material deposition rather than mechanical fastening or thermal joining.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The additive manufacturing process deposits header material in layers that progressively enclose and encapsulate the tube ends. Each layer is deposited around the tubes, with subsequent layers nesting within and securing the previous layers, ultimately forming a complete header envelope that tightly seals around the tubes. This nested deposition approach ensures leak-free joints while automating the manufacturing process.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Adaptability or versatility

If traditional fastening techniques are used, then joints can be made, but material choices are limited to metals with similar melting points

Engineering Contradiction:
Improvematerial selection rangeVSAvoidmanufacturing process flexibility
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The additive manufacturing process enables the use of composite materials by depositing header material that can be the same as or different from the tube material. The system can handle thermoplastics, ceramics, and metals, creating composite structures where the header and tubes are made from different material classes. This approach eliminates the melting point compatibility constraints of traditional joining methods, as the additive process builds material layer-by-layer without requiring thermal joining of dissimilar metals.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the fundamental manufacturing parameter from thermal joining (welding/brazing) to additive material deposition. This parameter change allows the use of diverse materials including thermoplastics and ceramics that would be incompatible with traditional thermal joining processes. The additive process controls material placement through deposition parameters rather than thermal cycles, enabling flexibility in material selection across different material classes.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If headers are manufactured by stacking plates with welding, then headers can be assembled, but the process is labor intensive and slow

Engineering Contradiction:
Improvemanufacturing speedVSAvoidmanufacturing complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The additive manufacturing process performs preliminary action by depositing header material layer-by-layer directly around the tube ends in their final positions. Tubes are stacked to the desired configuration first, then the header is built up around them in a single continuous process. This eliminates the need for separate plate stacking, alignment, and welding operations, significantly improving manufacturing speed while reducing process complexity through automation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent merges multiple manufacturing operations into a single additive manufacturing process. The header formation and tube joining operations are combined into one continuous deposition process, where the header is built up around the tubes in a single automated sequence. This merging of operations eliminates the need for separate plate stacking and welding steps, improving productivity while the automated nature of additive manufacturing reduces operational complexity.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables efficient, leak-proof assembly of heat exchanger headers using diverse materials, including thermoplastics, ceramics, and metals, reducing labor intensity and enhancing manufacturing speed.

Implementation Method 1

the header envelope is produced in-situ by additive manufacturing as the tubes are stacked in the heat exchanger

Methodology Applied
Scientific EffectAdditive manufacturing: 3D Printing

Data Source

PatentEP3645196B1Additive manufactured header for heat exchangers
Publication Date: 2025.12.10 EVAPCO INC
  • EP3645196B1 patent drawingFigure 1~2
  • EP3645196B1 patent drawingFigure 3~4
  • EP3645196B1 patent drawingFigure 5~6

AI summary

A stacked tube heat exchanger consisting of tubes that are affixed to a header or headers that are additively manufactured.