HPLC to SFC Flow Path Conversion via Rotary Valve
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Solution Overview
Problem
Current high-pressure liquid chromatography (HPLC) systems face challenges in accurately metering compressible fluids due to fluid compressibility, leading to flow pulsations and variations in pressure, which degrade the quality of the process stream and require additional components to correct, affecting speed, cost, and energy efficiency.
Innovation Solution
The implementation of a system that converts a standard HPLC flow path to a supercritical fluid chromatography (SFC) flow path using a high-pressure rotary valve to switch between modes, maintaining fluidic communication and allowing for the use of a booster pump with prechiller, pulse dampener, and thermal conditioning device to manage fluid compressibility and flow accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard HPLC flow path is used for pumping compressible fluids, then the system can operate in conventional liquid chromatography mode, but fluid compressibility causes flow pulsations and pressure variations that degrade process stream quality
Solution Approach 1:
The patent applies phase transition by converting the fluid state from conventional liquid (HPLC) to supercritical fluid (SFC) mode. This phase transition allows the system to handle compressible fluids like CO2 in a controlled manner, where the fluid exhibits properties between gas and liquid, reducing the harmful compressibility effects that cause flow pulsations and pressure variations while maintaining continuous flow capability.
Solution Approach 2:
The system dynamically switches between HPLC and SFC operational modes using a high-pressure rotary valve. This dynamic adaptation allows the system to optimize performance for different fluid types and application requirements, resolving the contradiction by enabling the system to operate in SFC mode when handling compressible fluids to eliminate flow pulsations while maintaining the ability to switch to HPLC mode for conventional liquid applications.
2Reliability
If additional components are added to correct flow pulsations and pressure variations, then process stream quality improves, but system complexity, cost, and energy consumption increase
Solution Approach 1:
The high-pressure rotary valve serves multiple functions: it switches between HPLC and SFC flow paths, maintains fluidic communication, and enables the system to handle both incompressible liquids and compressible supercritical fluids. This multi-functionality resolves the contradiction by providing a single component that addresses process stream quality without requiring multiple separate correction devices, thereby reducing system complexity while maintaining reliability.
Solution Approach 2:
The system uses an intermediary approach by introducing a booster pump with prechiller and thermal conditioning devices that mediate between the fluid source and the main flow path. These components prepare the compressible fluid (cooling and pressurizing it) before it enters the chromatography system, reducing flow pulsations and pressure variations without requiring extensive additional correction components downstream, thus balancing process stream quality with system complexity.
3Measurement precision
If a booster pump with prechiller and thermal conditioning devices is used, then accurate volumetric delivery of compressible fluids is achieved, but system cost and energy consumption increase
Solution Approach 1:
The system applies preliminary action by pre-cooling and pre-pressurizing the compressible fluid (e.g., CO2) before it enters the main chromatography flow path. The prechiller and thermal conditioning devices prepare the fluid in advance, ensuring it reaches the required temperature and pressure conditions for accurate volumetric delivery. This preliminary preparation resolves the contradiction by achieving measurement precision through advance fluid conditioning rather than requiring continuous energy-intensive correction during operation.
Solution Approach 2:
The system changes physical parameters (temperature and pressure) of the compressible fluid through thermal conditioning and pressurization. By controlling these parameters in advance, the system achieves accurate volumetric delivery of compressible fluids. The parameter changes resolve the contradiction by transforming the fluid to a state where compressibility effects are minimized, enabling precise metering without requiring excessive energy during the actual chromatography operation.
4Adaptability or versatility
If HPLC systems are converted to SFC operations, then usability of existing systems is extended, but system configuration and operation complexity increase
Solution Approach 1:
The high-pressure rotary valve provides multi-functionality by enabling the system to operate in both HPLC and SFC modes using a single flow path configuration. This universal component allows existing HPLC systems to be converted to SFC operations without requiring completely separate flow paths or multiple specialized valves, thereby extending system usability while minimizing the increase in configuration complexity.
Solution Approach 2:
The system inverts the conventional approach by using the same flow path for both HPLC and SFC operations, switching modes through the rotary valve rather than requiring separate dedicated paths. This inversion resolves the contradiction by extending system versatility through a unified configuration, reducing the complexity that would arise from maintaining separate HPLC and SFC flow paths.
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 enables accurate and precise volumetric delivery of compressible fluids with reduced pulsation and noise, allowing for continuous high-pressure flow without the need for extensive additional components, improving the quality of the process stream and extending the usability of existing HPLC systems to SFC operations.
Implementation Method 1
uses a device or process to selectively switch flowpaths to achieve different modes of operation such as HPLC and SFC. Preferably, a single valve, for example a high pressure rotary valve, is used to 1) assure all fluid lines are switched simultaneously
Implementation Method 2
allowing for the use of a booster pump with prechiller, pulse dampener, and thermal conditioning device to manage fluid compressibility and flow accuracy
Implementation Method 3
allowing for continuous high-pressure flow without the need for extensive additional components, improving the quality of the process stream
Implementation Method 4
thermal conditioning device to manage fluid compressibility and flow accuracy
Data Source
AI summary
An apparatus, system, and process of converting a standard, high performance liquid chromatography (HPLC) flow path to a flow path suitable for supercritical fluid chromatography (SFC) are described. This reversible technique is applied to a variety of flow configurations including binary, high pressure solvent mixing systems and quaternary, low pressure solvent mixing systems than can be conventionally operated or automated. The technique is generally applied to the fields of supercritical fluid chromatography and high pressure liquid chromatography, but users skilled in the art will find utility for any flow system where pressurization components must be periodically applied to and removed from both ends of a flow stream in an automated manner.