Makeup Pump Flow Control for LC Detector Bypass

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Solution Overview

Problem

Chromatography systems face challenges in smoothly redirecting mobile phase flow without positioning a valve inline between the column and detector, especially when dealing with fluid valves that have a larger fluidic volume and form factor, leading to space constraints and chromatographic band-broadening.

Innovation Solution

A method and system that utilize a makeup pump to control fluid flow, allowing the output of the chromatography column to bypass the fluid valve and reach the detector or be directed to waste, using restrictors to manage flow rates and minimize post-column volume, thereby eliminating the need for a valve in the direct flow path between the column and detector.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a valve is positioned inline between the column and detector to redirect mobile phase flow, then flow diversion capability is achieved, but post-column volume increases causing chromatographic band-broadening

Engineering Contradiction:
Improveflow diversion capabilityVSAvoidchromatographic resolution
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The valve is extracted from the direct flow path between column and detector, eliminating the source of band-broadening while preserving flow diversion capability through alternative routing architecture

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A flow splitter and restrictors are introduced as intermediary components to manage flow distribution, allowing valve positioning away from the critical detection path while maintaining control over mobile phase routing

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a fluid valve with larger form factor is used to redirect mobile phase flow, then flow control capability is improved, but space constraints in the system are worsened

Engineering Contradiction:
Improveflow control capabilityVSAvoidsystem space
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

The system architecture transitions from linear inline valve positioning to a multi-path routing configuration, effectively utilizing spatial dimensions to accommodate larger valve components outside the constrained detection path area

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If a valve is positioned inline to divert mobile phase flow, then flow diversion is achieved, but detector contamination increases

Engineering Contradiction:
Improveflow diversion capabilityVSAvoiddetector contamination
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The valve and associated flow control components are extracted from the direct path to the detector, removing the mechanism that causes contamination while preserving the ability to divert flows through alternative routing

Inventive Principle:
Principle #2Taking out (Extraction)

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 reduces post-column system dispersion and allows for flow diversion in space-constrained environments, maintaining the detector clean and preventing chromatographic band-broadening, while enabling efficient operation in integrated LC-MS systems.

Implementation Method 1

a makeup pump configured to pump a makeup fluid into the chromatography system

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

The passive splitter is further configured to reduce pressure of the split flow stream, causing volumetric expansion of the split flow stream

Methodology Applied
Scientific EffectPressure reduction and volumetric expansion: Depressurisation

Data Source

PatentEP3803378B1Method for controlling fluid flow within a liquid chromatography system comprising a makeup pump
Publication Date: 2025.06.25 WATERS TECHNOLOGY CORP
  • EP3803378B1 patent drawingFigure 1A~1B
  • EP3803378B1 patent drawingFigure 2
  • EP3803378B1 patent drawingFigure 3A~3B

AI summary

The present disclosure relates to methodologies, systems, and apparatus for controlling fluid flow within a chromatography system. The chromatography system includes a mobile phase pump configured to pump a liquid mobile phase through a column and a restrictor positioned downstream of the column and upstream of a detector. The system also includes a valve configured to operate in at least two positions. In a first position, the valve is configured to direct the output of the column to bypass the valve and reach the detector, while in the second position the valve directs the output of the column to waste.