Pressure Compensation Valve Flow Path for Precise Microfluidic Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluid flow control valves face challenges in miniaturization and precision due to high biasing forces required to counteract pressure differences, leading to increased size and power requirements, and are affected by external factors like supply pressure and flow rates, which complicates accurate control, especially in micro-fluidic applications.
Innovation Solution
A valve assembly with a pressure compensation chamber and a pressure compensation flow path that includes at least one opening between the armature and the flexible membrane, featuring axial portions with different cross-sectional areas, allowing for quicker transmission of pressure fluctuations and improved flow characteristics, enabling more precise control and reduced friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high biasing force is used to counteract high pressure difference across the valve element, then the valve can remain reliably closed, but the actuator size and power requirements increase
Solution Approach 1:
A pressure compensation chamber is introduced as an intermediary space between the valve element and the actuator. This chamber receives compensation fluid through a compensation flow path, generating a pressure compensation force that counteracts the pressure difference across the valve element. The solenoid actuator only needs to overcome the biasing member force plus any residual force, rather than the full pressure difference, significantly reducing actuator size and power requirements while maintaining reliable valve control
Solution Approach 2:
The patent employs hydraulic/pneumatic pressure compensation by introducing a compensation fluid through a compensation flow path into the pressure compensation chamber. The pressure of this compensation fluid generates a force that compensates for the pressure difference across the valve element, allowing the use of a smaller actuator while maintaining valve stability under high pressure differences
2Volume of moving object
If the valve assembly is miniaturized for micro-fluidic applications, then the valve size is reduced, but precision and control accuracy deteriorate due to high biasing forces
Solution Approach 1:
The pressure compensation chamber acts as an intermediary that decouples the relationship between valve size and required actuator force. By introducing compensation fluid pressure to counteract the pressure difference, the system maintains precise control capability in miniaturized valves, as the actuator only needs to provide sufficient force to overcome the biasing member rather than the full pressure load
Solution Approach 2:
The patent changes the force balance parameters by introducing a compensation force that counteracts the pressure difference. This parameter change allows the valve to maintain precision control with reduced actuator force requirements, enabling miniaturization without sacrificing control accuracy
3Reliability
If the pressure compensation flow path has a long axial portion, then pressure compensation is effective, but the valve assembly length increases
Solution Approach 1:
The compensation flow path is configured to extend radially outward from the valve element and then axially into the pressure compensation chamber, rather than extending purely axially. This dimensional change in the flow path configuration allows effective pressure compensation while minimizing the axial length of the valve assembly
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 solution enhances the precision and repeatability of valve operation by optimizing pressure compensation, reducing the impact of external pressures and flow rates, and minimizing friction, resulting in a more compact and efficient valve design.
Implementation Method 1
A pressure compensation chamber is provided in which only the armature is entirely enclosed. A flexible membrane forms a seal against the moveable member and the valve body to divide the valve chamber into a flow chamber in which the valve seat and valve element are located and a pressure compensation chamber
Implementation Method 2
The pressure compensation flow path has at least one opening extending into the pressure compensation chamber at an axial position between the armature and the flexible membrane
Implementation Method 3
A solenoid may be used to generate a magnetic field which can exert a magnetic force on a moveable member to provide opening, closing and/or switching of the valve
Implementation Method 4
Such valves typically include a biasing member that generates a biasing force to oppose the magnetic force
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A valve assembly (100) is disclosed, which includes a valve body (110) defining a valve chamber (115) and a moveable member (120). The moveable member (120) has a valve element (121) at its first end and an armature (122) at its second end. The moveable member (120) is moveable in an axial direction to selectively open and close the valve. The entire moveable member is spaced from the walls of the valve body when the valve is open or partially open. A flexible membrane (140) forms a seal against the moveable member (120) and the valve body to divide the valve chamber (115) into a flow chamber in which the valve seat and valve element are located and a pressure compensation chamber (116) within which the armature is entirely enclosed. A first fluid port (111) is fluidly connected to the pressure compensation chamber (116) via one or more bores in a pressure compensation flow path (160) with at least one opening extending into the pressure compensation chamber (116) at an axial position between the armature (122) and the flexible membrane (140). The pressure compensation flow path (160) includes a first axial portion (161) with a first cross-sectional area and a second axial portion (162) with a second, smaller cross-sectional area.