Capacitive Flow Sensor for Particulate Media Dispensing
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Solution Overview
Problem
Existing flow control valves for particulate media face issues such as complexity, manufacturability problems, and functionality issues due to spring-loaded pintles that can wear or break, and lack accurate measurement of particulate flow, leading to poor control and unpredictable flow patterns.
Innovation Solution
A valve design featuring a funnel with repelling magnets and a shield to direct particulate media through a central path, using a shuttle with magnetic components and eddy currents for damping, and a capacitive flow sensor with sensing rings to accurately measure and control the flow, eliminating the need for springs and improving flow regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring-loaded pintle is used to control valve closure, then the valve can return to closed position, but the spring can wear, break, or become damaged creating reliability issues
Solution Approach 1:
The patent replaces the mechanical spring system with an air pressure system. Compressed air is introduced into the valve body to push the pintle to the closed position, eliminating the spring component that causes wear and failure. This substitution of mechanical elasticity with pneumatic pressure resolves the reliability issue while maintaining the valve's ability to return to closed position.
Solution Approach 2:
The patent removes the spring component entirely from the valve assembly. By extracting the problematic spring element and replacing its function with compressed air pressure, the design eliminates the source of wear, breakage, and damage while simplifying the overall valve structure.
2Ease of operation
If a fixed orifice and movable pintle design is used, then flow control is achieved, but the pintle can bounce when actuated creating control problems
Solution Approach 1:
The patent replaces mechanical spring loading with pneumatic pressure control. Compressed air provides smooth, controlled pressure to move the pintle without the sudden release and bounce associated with spring mechanisms. This pneumatic actuation method eliminates bouncing while maintaining precise flow control capability.
3Extent of automation
If no flow measurement system is implemented, then the valve structure remains simple, but closed loop control of the valve cannot be achieved
Solution Approach 1:
The patent incorporates a flow sensor that measures the actual flow rate of particulate media passing through the valve. This measurement is fed back to the control system, which adjusts the air pressure and pintle position to maintain the desired flow rate. This feedback mechanism enables closed-loop control, allowing the valve to automatically compensate for variations and maintain precise flow regulation.
Solution Approach 2:
The valve design integrates multiple functions into a single system: flow control through pintle positioning, flow measurement through the sensor, and automatic adjustment through closed-loop control. This multi-functional integration achieves automation while managing complexity through unified design.
4Measurement precision
If traditional flow sensors are used that rely on arm displacement or non-contacting styles, then flow measurement is attempted, but measurement accuracy deteriorates when media type changes or flow stream is unpredictable
Solution Approach 1:
The patent replaces mechanical arm displacement sensors with a pneumatic flow measurement system. By measuring the air pressure and flow rate required to move the pintle and maintain equilibrium, the system indirectly measures particulate flow without mechanical contact. This substitution eliminates sensitivity to media type changes and unpredictable flow patterns.
Solution Approach 2:
The patent uses compressed air as an intermediary medium to both actuate the pintle and measure flow. The air pressure required to balance the forces on the pintle provides information about the particulate flow rate. This intermediary approach allows measurement without direct contact with varying media, improving adaptability and accuracy.
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 provides reliable and accurate control of particulate flow, reducing bounce and oscillation of the shuttle, ensuring consistent and precise dispensing of media, and enabling closed-loop control of the valve operation.
Implementation Method 1
The inlet portion has repelling magnets and a shield. The inlet portion has a shuttle sleeve that carries the particulate media on the inside. Surrounding the outside of the shuttle sleeve is a movable shuttle. The shuttle has shuttle magnets
Implementation Method 2
The inlet portion has repelling magnets and a shield. The shield reduces the magnetic field from the magnet that passes through the center of the valve. The shuttle has shuttle magnets and a magnetic shield that reduces the magnetic field from the magnets
Implementation Method 3
A portion of the valve is made from a metal, such as brass or copper that interacts with the shuttle magnets to generate eddy currents when the shuttle is in motion. The eddy currents act to dampen the movement of the shuttle.
Implementation Method 4
A portion of the valve is made from a metal, such as brass or copper that interacts with the shuttle magnets to generate eddy currents when the shuttle is in motion
Implementation Method 5
A capacitive flow sensor uses sensing rings in conjunction with a fixed flow director. The flow sensor uses a funnel portion near or at an inlet to direct flow towards the center.
Data Source
AI summary
A flow sensor for use downstream from a particulate media dispensing device is provided having an inlet to receive particulate media and an outlet to dispense the media. The flow sensor has an inlet portion with a funnel to direct particulate media towards a central axis. An axially mounted flow director is located downstream from the funnel to direct the media outwards towards a sensor portion. A capacitive sensor located in the sensor portion surrounds the flow director to create an annular flow path to measure the amount of media that passes through sensor rings in the sensor.