Elastic Pinch Valve Geometry for Low-Shear Flow Control
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Solution Overview
Problem
Conventional pinch valves and diaphragm control valves in the biopharmaceutical industry face challenges in controlling fluid flow with minimal shearing forces, leading to flow losses and potential damage to biological molecules during processing.
Innovation Solution
A pinch valve design that combines the flexibility of hose pinch valves with the control performance of diaphragm valves, featuring a valve body with a peripheral wall of elastic material and force transmission elements that change the cross-sectional area of the flow channel to control fluid flow without deflections, thereby minimizing shearing forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional pinch valve is used to control fluid flow, then the valve structure is simple and easy to manufacture, but the flow velocity becomes non-uniform causing high shearing forces that damage biological molecules
Solution Approach 1:
The flow channel cross-section is designed with non-circular geometry (oval, rectangular, or square) to create uniform flow velocity distribution. This local geometric modification ensures that fluid flows evenly through the channel without creating high-velocity zones that generate damaging shear forces, while the overall valve structure remains simple and manufacturable
2Manufacturing precision
If a diaphragm control valve is used to achieve precise flow control, then the control performance is improved, but the valve structure becomes more complex
Solution Approach 1:
The valve utilizes the elastic properties of the circumferential wall material to achieve flow control. By applying external force to deform the elastic wall, the flow channel cross-section can be precisely adjusted without complex mechanical components. This parameter-based control (using material elasticity) provides diaphragm-valve-level precision while maintaining structural simplicity
3Adaptability or versatility
If the circumferential wall is made of elastic material to enable flow control, then the valve achieves flexible flow regulation, but the structural complexity increases
Solution Approach 1:
The elastic circumferential wall serves multiple functions simultaneously: it forms the structural boundary of the flow channel, provides the mechanism for flow regulation through deformation, and ensures uniform flow velocity distribution. This multi-functionality eliminates the need for separate control components, achieving flexible flow regulation without increasing overall structural complexity
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 pinch valve achieves optimized process control with reduced shearing forces, ensuring gentle transport of liquids and preventing damage to biological molecules, while maintaining uniform flow velocity and minimizing flow losses.
Implementation Method 1
The circumferential wall consists of an elastic or yielding material. If a compressive or tensile force acts on a force transmission element, this force transmission element can be displaced perpendicular to the flow direction of the flow channel. The first and second force transmission elements, or the force transmission element and the fixing element when a compressive or tensile force acts on a force transmission element, are displaceable relative to each other perpendicular to the flow direction of the flow channel.
Data Source
Figure 1
Figure 2~4
Figure 5~6
AI summary
The invention relates to a pinch valve comprising a valve element (4) with precisely one flow channel (20) that is surrounded by a circumferential wall (21) and has an inlet opening (24), which is designed for connecting a connection member (2) or which adjoins a connection element (2a), at a first end and an outlet opening (25), which is designed for connecting a connection member (2) or adjoins a connection element (2a), at a second end. The valve element (4) additionally has a pair of force transmitting elements (19, 19') or a force transmitting element (19) and a fixing element (26) which are connected to the circumferential wall (21) in a central closing region (18) that is arranged between the inlet opening and the outlet opening. The force transmitting elements (19, 19') or the force transmitting element (19) and the fixing element (26) are arranged at least substantially perpendicularly to the flow direction of the flow channel (20). The circumferential wall (21) consists of an elastic material such that the force transmitting elements (19, 19'), or the force transmitting element (19) and the fixing element (26), can be moved towards each other under the effect of a pressure or tensile force perpendicularly to the flow direction of the flow channel (20). In the absence of a pressure or tensile force acting on a force transmitting element (19, 19'), the circumferential wall (21) has a cross-section which differs from a circle in the central closing region (18). In the cross-section, the circumferential wall (21) surrounds a flow channel (20) surface area which is constant at least substantially over the entire valve element (4). Thus, the average flow speed is at least substantially uniform at all positions along the valve element (4).