Thermal Modulator for Chromatography Using Peltier Cooling and Resistive Heating
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Solution Overview
Problem
Chromatography systems face challenges in achieving fast heating and low temperatures for narrow reinjection, with high operating expenses associated with liquid nitrogen cooling systems making them commercially impractical.
Innovation Solution
A thermal modulator system comprising a cooler, thermal valve, thermal buffer, and heater, utilizing anisotropic materials and thermoelectric coolers to efficiently modulate temperatures within a capillary, distributing heat over a surface to optimize cooling and heating processes, and incorporating a cold reservoir to manage heat flow effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If liquid nitrogen cooling systems are used to achieve cryogenic temperatures, then cooling performance is improved, but operating expenses increase and commercial practicality decreases
Solution Approach 1:
The patent replaces expensive liquid nitrogen cooling systems with inexpensive Peltier cooler modules that can be easily replaced. The Peltier coolers achieve sufficient cooling performance for the application without the high operating costs of liquid nitrogen, making the system commercially practical while maintaining adequate cryogenic temperatures for analyte trapping.
Solution Approach 2:
The patent changes the cooling approach from cryogenic liquid nitrogen temperatures to moderate temperatures achievable by Peltier coolers. By adjusting the temperature parameter to match the actual needs of analyte trapping rather than using extreme cryogenic temperatures, the system achieves cost-effective operation while maintaining functional performance.
2Speed
If fast heating is achieved by hot gas jets or hot air baths, then heating speed is improved, but temperature control precision and energy efficiency deteriorate
Solution Approach 1:
The patent extracts the heating function from the bulk thermal environment and implements a localized heating element (resistive heater) that directly contacts the capillary. This allows fast heating of only the necessary region without heating large volumes of gas or surrounding structures, dramatically improving energy efficiency while maintaining fast heating speed.
Solution Approach 2:
The patent introduces a thermal buffer as an intermediary between the heater and the cooler. This thermal buffer with high thermal mass and high thermal conductivity materials enables rapid heat transfer to the capillary during heating phases while preventing excessive thermal load on the cooler during cooling phases, improving both heating speed and overall energy efficiency.
3Stability of the object's composition
If thermal mass is increased to improve temperature stability, then temperature control is improved, but heating speed and response time deteriorate
Solution Approach 1:
The patent segments the thermal management system into distinct functional zones: a heated zone with the capillary and heater for fast local temperature changes, and a cooled zone with the Peltier cooler and thermal buffer for thermal stabilization. This segmentation allows different parts of the system to have different thermal characteristics, enabling both fast heating and stable temperature control simultaneously.
Solution Approach 2:
The thermal buffer acts as an intermediary with high thermal mass that stabilizes the overall system temperature while allowing rapid local heating of the capillary. The high thermal conductivity materials in the thermal buffer enable quick heat distribution when needed, reconciling the contradiction between thermal mass for stability and speed for response.
4Loss of energy
If anisotropic materials are used to distribute heat over a surface, then cooling efficiency is improved, but device complexity increases
Solution Approach 1:
The patent uses composite materials in the thermal buffer, combining high thermal conductivity materials (such as aluminum or copper) with high thermal mass materials. This composite structure efficiently distributes heat over the surface area of the Peltier cooler, maximizing cooling efficiency without requiring complex anisotropic material structures, thus maintaining relative simplicity.
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 system achieves efficient thermal control, allowing for narrow reinjection bands at high frequencies while minimizing the thermal load on the cooling device, effectively utilizing the cooling source and maintaining temperature control within operational limits.
Implementation Method 1
systems using liquid nitrogen for cooling are sought for high performance... One aspect of the present disclosure provides a thermal modulator for a chromatographic system. The thermal modulator includes a cooler... the first cooler is thermoelectric
Implementation Method 2
Fast heating has been achieved by... resistive heating of metal capillary columns... The heater thermally-engages the thermal buffer
Implementation Method 3
the thermal valve includes an anisotropic material operable to transfer heat at a first rate in the first direction and at a second rate in a second direction transverse to the first direction
Data Source
AI summary
A thermal modulator for a chromatographic system includes a cooler, a thermal valve, a thermal buffer, a heater, and a capillary. The thermal valve thermally-engages the cooler. The thermal buffer thermally-engages the thermal valve. The heater thermally-engages the thermal buffer. The capillary thermally-engages the heater and is configured to transport an analyte in a first direction.