Self-Supporting Cartridge Heater Wire for High Power Density

Solution Overview

Problem

The manufacturing of electric cartridge type heaters with one-sided electrical contacting is challenging, especially for high-performance heaters requiring high power densities, as it involves mechanical stress on the resistance wire, leading to manufacturing complexities and increased costs, and compromises in resistance values and wire cross-sections.

Innovation Solution

The use of a self-supporting electric resistance wire, which maintains its shape and spacing without external mechanical stress, allowing for simpler insertion and insulation within the tubular metallic jacket, reducing manufacturing efforts and costs, and enabling tighter coil pitches and closer wire-jacket distances for improved heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If mechanical stress is applied to the resistance wire during manufacturing to achieve high power density, then the coil pitch can be reduced and power density increased, but the manufacturing complexity and cost increase

Engineering Contradiction:

Improvepower densityVSAvoidmanufacturing complexity

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The resistance wire is pre-formed into a coil structure with the desired pitch and dimensions before insertion into the jacket. This preliminary shaping eliminates the need for complex in-process mechanical stress application and maintaining devices, as the wire already has the required geometry for high power density when it is inserted and insulated

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The manufacturing process is divided into separate steps: first forming the resistance wire coil independently, then inserting it into the jacket, and finally applying insulation material. This segmentation removes the need for complex integrated systems that would be required to maintain mechanical stress throughout the entire manufacturing process

Inventive Principle:

Principle #1Segmentation

2Stability of the object's composition

If mechanical stress is applied to maintain coil spacing, then the coils can be kept at spaced locations, but the manufacturing process becomes more complex and costly

Engineering Contradiction:

Improvecoil spacing stabilityVSAvoidmanufacturing process complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The resistance wire is pre-formed into a coil structure with the desired pitch and dimensions before insertion into the jacket. This preliminary shaping eliminates the need for complex in-process mechanical stress application and maintaining devices, as the wire already has the required geometry for high power density when it is inserted and insulated

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

An electrically insulating material is introduced as an intermediary substance that fills the spaces between coils and against the jacket surface. This insulating material physically maintains the coil spacing and prevents electrical contact, replacing the need for complex mechanical stress application and maintaining devices

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If the resistance wire is inserted without pre-forming, then the manufacturing process is simpler, but achieving tight coil pitches and small clearances becomes difficult

Engineering Contradiction:

Improveinsertion simplicityVSAvoidcoil pitch precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The resistance wire is pre-formed into a coil structure with the desired pitch and dimensions before insertion into the jacket. This preliminary shaping eliminates the need for complex in-process mechanical stress application and maintaining devices, as the wire already has the required geometry for high power density when it is inserted and insulated

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

This approach enhances manufacturing efficiency, reduces costs, and achieves precise tolerances in cylindrical shape, coaxiality, and concentricity, enabling reliable high-power density designs with improved heat transfer and reduced risk of mechanical failure.

Implementation Method 1

at least one resistance wire, which produces heat if an electrical current passes through the resistance wire

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the at least one resistance wire is electrically insulated from the first tubular metallic jacket by an electrically insulating material arranged in the interior of the first tubular metallic jacket

Methodology Applied

Scientific EffectElectrical insulation: Electrical Resistance

Data Source

PatentUS10076002B2Electric cartridge type heater and method for manufacturing same

Publication Date: 2018.09.11 TUERK & HILLINGER GMBH & CO

AI summary

An electric cartridge type heater (100, 200, 300, 400, 500, 600, 700, 800, 900, 1000) has at least one the tubular metallic jacket (101, 201, 301, 401, 501, 601, 701, 801, 901, 1001), at least one electric resistance wire (102, 202, 302, 402, 502, 602, 702, 802, 902, 1002) arranged in the interior space of the tubular metallic jacket with two ends for electrically contacting the electric resistance wire, wherein the at least one electric resistance wire is electrically isolated from the tubular metallic jacket by an electrically insulating material (103, 203, 303, 403, 503, 603, 703, 903) arranged in the interior space of the tubular metallic jacket (101, 201, 301, 401, 501, 601, 701, 801, 901, 1001). The electric resistance wire is self-supporting. A method is also provided for manufacturing such an electric cartridge type heater.