HPLC Sample Injector Flow Direction Controller
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sample injectors in high performance liquid chromatography (HPLC) systems face challenges in precisely controlling fluid flow and managing multiple functions, leading to inappropriate valve configurations that increase dead volume and reduce separation accuracy.
Innovation Solution
A sample injector with a metering device and a flow direction controller that enables defined fluid flow directions, allowing the metering device to operate outside the main flow path, reducing dead volume and enhancing separation accuracy by using a combination of passive and actively controlled flow direction valves to manage fluid flow during sample intake and separation modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional switchable valves and injector architectures are used to support multiple functions, then device versatility is improved, but dead volume increases and separation accuracy deteriorates
Solution Approach 1:
The metering device is extracted from the main flow path and positioned in a bypass configuration. This allows the metering device to perform sample intake and preprocessing functions without being part of the critical separation flow path, thereby eliminating the source of dead volume while preserving multi-function capability through the bypass connection
2Ease of operation
If the metering device is positioned in the main flow path, then sample intake function is achieved, but dead volume increases and separation accuracy deteriorates
Solution Approach 1:
The metering device is extracted from the main flow path and repositioned in a bypass configuration. The injector valve selectively connects the bypass line to either the sample container or the main flow path, enabling sample intake through the bypass while keeping the metering device outside the critical separation path during analysis
Solution Approach 2:
The injector valve provides dynamic switching capability that reconfigures the flow paths based on operational mode. During sample intake, the bypass is connected to the sample container; during separation, the bypass is disconnected from the main flow path, creating a dynamic system that adapts to different functional requirements
3Device complexity
If passive flow direction valves are used to control fluid flow, then device complexity is reduced, but flow control precision deteriorates
Solution Approach 1:
The patent combines both passive flow direction valves and actively controlled injector valve in a unified system. The passive valves handle basic flow direction control with simple construction, while the actively controlled injector valve provides precise flow path switching. This merging allows each component to operate in its optimal performance range
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 configuration improves the precision and reproducibility of sample separation by minimizing dead volume and allowing the metering device to perform additional tasks, such as precompression and decompression, while maintaining efficient operation across all modes.
Implementation Method 1
a flow direction controller configured for defining an enabled flow direction of fluid displaced by the metering device and for defining a disabled flow direction
Implementation Method 2
a metering device being operable for displacing fluid and for intaking a metered amount of the sample fluid into the sample injector
Implementation Method 3
a mobile phase drive through a separation unit for separating compounds of the sample fluid in the mobile phase... at high pressure (typically 20-100 MPa, 200-1000 bar)
Implementation Method 4
a separation unit, particularly a chromatographic column, configured for separating the compounds of the sample fluid in the mobile phase
Data Source
AI summary
A sample injector configured to introduce a sample fluid into a mobile phase, wherein the mobile phase is to be driven by a mobile phase drive through a separation unit for separating compounds of the sample fluid in the mobile phase, wherein the sample injector comprises a metering device being operable for displacing fluid and for intaking a metered amount of the sample fluid into the sample injector, an injector valve being switchable for operating the sample injector selectively in a sample intake mode in which the metering device is operable to intake the sample fluid from a sample container, or a separation mode in which intaken sample fluid is driven between the mobile phase drive and the separation unit for separating the compounds, and a flow direction controller configured for defining an enabled flow direction of fluid displaced by the metering device and for defining a disabled flow direction.