Gradient Proportioning Valve With Tight-Tolerance Pressure Pulse Control
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Solution Overview
Problem
Existing gradient proportioning valves (GPVs) in liquid chromatography systems generate undesirable pressure pulses during actuation, leading to compositional errors and reduced accuracy, particularly at higher flow rates, and existing solutions like accumulator diaphragms are costly and limit design freedom.
Innovation Solution
A gradient proportioning valve with a piston and bored structure having tight tolerances to create a fluid-tight seal without deformable seals, using ceramic materials and precise clearances of less than 6 microns to minimize pressure pulses, and actuation mechanisms that rotate or move axially to control fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compliant diaphragms or poppets are used to form seals in GPV, then sealing function is achieved, but pressure pulses are generated causing compositional errors
Solution Approach 1:
The patent removes the compliant sealing elements (diaphragms or poppets) that generate pressure pulses, replacing them with a needle valve mechanism that provides sealing through a needle tip against a seat, eliminating the source of harmful pressure pulses while maintaining sealing function
Solution Approach 2:
The patent replaces the traditional mechanical sealing system (compliant diaphragms or poppets) with a precision needle valve mechanism where a needle tip creates a fluid-tight seal against a seat, substituting one mechanical sealing approach with another that eliminates pressure pulse generation
2Object-generated harmful factors
If accumulator diaphragms are used upstream of inlet channels to mitigate pressure pulses, then pressure pulse mitigation is improved, but device complexity and cost increase
Solution Approach 1:
The patent eliminates the need for accumulator diaphragms by integrating pressure pulse mitigation directly into the valve actuation mechanism itself, removing the additional component and simplifying the overall valve structure
Solution Approach 2:
The patent combines the sealing function and pressure pulse mitigation function into a single integrated needle valve mechanism, where the needle valve both seals the inlet channel and inherently dampens pressure pulses through its design, eliminating the need for separate accumulator components
3Object-generated harmful factors
If accumulator chambers are added to mitigate pressure pulses, then pressure pulse mitigation is improved, but manifold space requirements increase
Solution Approach 1:
The patent integrates pressure pulse mitigation functionality directly into the valve body structure through the needle valve mechanism, eliminating the need for separate accumulator chambers and thereby reducing the overall manifold volume requirements
4Productivity
If traditional solenoid valves are used to open and close inlet channels, then flow control is achieved, but compositional accuracy decreases due to pressure pulses
Solution Approach 1:
The patent replaces the traditional solenoid valve mechanism with a needle valve system that provides superior flow control and compositional accuracy by eliminating pressure pulses through its gradual opening and closing action and inherent damping characteristics
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 valve reduces or eliminates pressure pulses, enhancing compositional accuracy and performance across solvent composition ranges, especially at higher flow rates, without the need for additional sealing elements.
Implementation Method 1
the piston and the bored structure have a tight tolerance configured to create a fluid tight seal when the actuation mechanism closes the at least one of the plurality of conduits
Implementation Method 2
a manifold connected to each of the plurality of inlet ports configured to mix the plurality of fluids in a controlled manner to provide a fluid composition
Implementation Method 3
an actuation mechanism configured to open and close at least one of the plurality of conduits in a controlled manner
Implementation Method 4
A gradient proportioning valve with a piston and bored structure having tight tolerances to create a fluid-tight seal without deformable seals, using ceramic materials and precise clearances of less than 6 microns to minimize pressure pulses
Data Source
AI summary
Disclosed is a gradient proportioning valve for liquid chromatography that includes a plurality of inlet ports configured to receive a plurality of fluids, a manifold connected to each of the plurality of inlet ports configured to mix the plurality of fluids in a controlled manner to provide a fluid composition, the manifold including a plurality of conduits internal to the manifold, each of the plurality of conduits receiving fluid through a respective one of the plurality of inlet ports, an actuation mechanism having a piston located within a bored structure surrounding the piston, the actuation mechanism configured to open and close at least one of the plurality of conduits in a controlled manner where the piston and the bored structure have a tight tolerance configured to create a fluid tight seal, and a common outlet port configured to receive the fluid composition.