Modular GC Capillary Heating With Controlled Airflow Cooling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing gas chromatographs, particularly temperature gradient gas chromatographs, face challenges in achieving a compact design while maintaining functionality, ensuring easy replacement of separation capillaries, and providing a controlled fluid flow for temperature management, which is crucial for mobile and industrial applications.

Innovation Solution

A device for a gas chromatograph featuring a modular design with a heatable separation capillary positioned in a controllable fluid flow field, utilizing a generation unit to create a defined fluid flow field and a control device to manage the flow velocity, allowing for easy replacement and compact construction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the separation capillary is arranged in an air bath oven with intensive turbulent mixing, then temperature stability and homogeneity are improved, but thermal inertia increases and rapid measurements are hindered

Engineering Contradiction:
Improvetemperature stability and homogeneityVSAvoidthermal inertia during cooling
Core Design Contradiction:
TemperatureVSLoss of time

Solution Approach 1:

The air bath oven is segmented into multiple heating zones with independent temperature control, allowing different regions to be optimized for different functions (heating, cooling, temperature maintenance), thereby reducing overall thermal inertia while maintaining temperature stability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system employs dynamic temperature control where the oven temperature is actively adjusted based on real-time feedback from temperature sensors, enabling rapid response to cooling requirements while maintaining homogeneity during heating phases

Inventive Principle:
Principle #15Dynamics

2Loss of time

If electric heating is used to concentrate heat energy on the separation capillary, then thermal inertia is reduced, but temperature homogeneity deteriorates due to absence of air mixing

Engineering Contradiction:
Improvethermal inertiaVSAvoidtemperature homogeneity
Core Design Contradiction:
Loss of timeVSTemperature

Solution Approach 1:

The patent combines electric heating elements directly attached to the capillary with a controlled air flow system, merging the advantages of both methods: localized rapid heating from electric elements and temperature homogenization from controlled air convection

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

A controlled air flow acts as an intermediary medium that distributes heat evenly around the electrically heated capillary, preventing localized overheating while maintaining the rapid response characteristics of electric heating

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If a long separation capillary is used to achieve sufficient separation, then device volume increases, but compact design is compromised

Engineering Contradiction:
Improveseparation capabilityVSAvoiddevice volume
Core Design Contradiction:
Manufacturing precisionVSVolume of stationary object

Solution Approach 1:

The separation capillary is arranged in a helical or coiled configuration within a compact housing, nesting the long capillary path within a small volume by repeating the path in a spiral pattern, thereby achieving long capillary length without proportionally increasing device volume

Inventive Principle:
Principle #7Nested doll (Nesting)

4Ease of repair

If the separation capillary is made accessible for easy replacement, then device complexity increases, but maintenance ease is improved

Engineering Contradiction:
Improvecapillary replacement easeVSAvoiddevice complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The device is divided into modular sections with the separation capillary housed in a separate, easily accessible module that can be independently removed and replaced without disassembling the entire device, thereby simplifying maintenance while managing complexity through modular design

Inventive Principle:
Principle #1Segmentation

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 a compact, easily maintainable gas chromatograph with a separation capillary length of up to 6 m, facilitating easy replacement and precise temperature control through a defined fluid flow field, suitable for mobile and industrial applications.

Implementation Method 1

the separation capillary can be arranged or is arranged in a controllable fluid flow field

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

With forced convection, i.e., with a forced airflow, the cooling effect can be significantly increased and controlled

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 3

a metal separation capillary can be directly heated electrically

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 4

the separation capillary and/or a surrounding capillary sheath are heated by an electric current in the form of a resistance heater

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Implementation Method 5

The energy dissipated primarily involves emitted radiation, which increases particularly at higher temperatures

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 6

as well as convection of the air surrounding the separating capillary

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 7

a portion of the mixture that is adsorbed or absorbed by the coating of the separation capillary

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 8

a portion of the mixture that is adsorbed or absorbed by the coating of the separation capillary

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 9

a substance-specific phase equilibrium is established between a portion of the mixture to be analyzed that is in the carrier gas and a portion of the mixture that is adsorbed or absorbed by the coating

Methodology Applied
Scientific EffectPhase equilibrium:

Data Source

PatentEP4251991B1Device for a gas chromatograph, in particular a temperature-gradient gas chromatograph, and gas chromatograph comprising such a device
Publication Date: 2025.12.31 BOEKER PETER
  • EP4251991B1 patent drawingFigure 1~2
  • EP4251991B1 patent drawingFigure 3~5
  • EP4251991B1 patent drawingFigure 6a~7

AI summary

The present invention relates to a device (2) for a gas chromatograph, in particular a temperature gradient gas chromatograph. The invention further relates to a gas chromatograph having such a device (2). The device (2) comprises a module (4) and a separation capillary (16) arranged in the module (4), the separation capillary (16) being heatable and being arrangeable in a controllable fluid flow field of a fluid (12). A substance (20) to be analyzed by the gas chromatograph, in particular by the temperature gradient gas chromatograph, or a substance mixture (20) is able to be applied to the separation capillary (16). Further, the device (2) comprises a generation apparatus (10) for generating a fluid flow of the fluid (12), the generation apparatus (10) serving to influence a temperature of the separation capillary (16), and an influencing apparatus (14) for influencing the fluid flow of the fluid (12). A reception apparatus for accommodating the module (4) is provided, the module (4) being able to be inserted into the reception apparatus and being able to be removed from the reception apparatus.