Dialysis Control Valve Self-Cleaning Magnetic Flapper
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Solution Overview
Problem
Pneumatically-controlled dialysis machines face challenges in distinguishing between constant leaks due to foreign particle contamination and more serious leaks, leading to potential unnecessary shutdowns, as small particles can cause leaks in flapper valves, and existing systems lack effective self-cleaning mechanisms to address this issue.
Innovation Solution
A valve system with a magnetic flapper and electromechanical solenoid that includes a self-cleaning mode, where the flapper is moved to a neutral position between gas ports to dislodge debris, using varying voltages to assist in cleaning, and a feedback system to maintain optimal pressure, allowing the machine to automatically detect and fix leaks caused by foreign particle contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the alarm system is set at a threshold value just above the constant leak rate to distinguish dangerous leaks, then measurement precision is improved, but the system becomes unreliable because even constant leak rates vary from valve to valve and over time due to temperature and altitude fluctuations
Solution Approach 1:
The system performs a self-cleaning operation before the alarm triggers, attempting to remove foreign particles that cause variable leak rates. This preliminary action stabilizes the baseline leak rate by eliminating controllable sources of variation, allowing for more reliable threshold-based detection.
Solution Approach 2:
The valve system automatically cleans itself using the existing gas flow and pressure differential without external intervention. The flapper is moved to expose it to gas flow that removes foreign particles, and the system monitors whether the cleaning resolved the leak condition, eliminating the need for manual cleaning or complex adaptive thresholding.
2Manufacturing precision
If air filters are used to prevent foreign particles from entering the pneumatic system, then manufacturing precision is improved, but device complexity increases and some particles still make it into the system
Solution Approach 1:
The system converts the harmful presence of foreign particles into a beneficial self-cleaning operation. When particles cause a detectable leak condition, the system automatically initiates a cleaning sequence that uses the existing gas flow and pressure differential to remove the particles, transforming a contamination problem into a self-correcting feature.
Solution Approach 2:
The self-cleaning mechanism utilizes the existing pneumatic system's gas flow and pressure differential to remove foreign particles from the flapper. By directing gas flow across the flapper surface during a controlled cleaning operation, the system leverages aerodynamic forces to dislodge and remove particles without requiring mechanical contact or additional cleaning media.
3Reliability
If a self-cleaning mode is added to automatically detect and fix leaks caused by foreign particle contamination, then reliability is improved, but device complexity increases
Solution Approach 1:
The existing gas flow paths and pressure differential mechanisms are dual-used: they serve both the normal valve operation function and the self-cleaning function. The same gas ports and flapper mechanism used for flow control are also used to clean the flapper surface, eliminating the need for separate cleaning hardware and reducing overall system complexity.
Solution Approach 2:
The system implements periodic leak detection and self-cleaning cycles. When a leak condition is detected, the system automatically initiates a cleaning sequence, then re-evaluates the leak condition. This periodic monitoring and correction approach provides reliable leak management through simple conditional logic rather than continuous complex control.
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 system effectively detects and resolves leaks caused by foreign particles, ensuring the dialysis machine can resume normal operation by cleaning the flapper valve, reducing unnecessary shutdowns and maintaining reliable performance.
Implementation Method 1
an electromechanical solenoid and a gas valve including a magnetic flapper
Implementation Method 2
a flow of gas between the ports can be used to clean debris from the magnetic flapper
Implementation Method 3
The controller can also provide a varying voltage to the electromechanical solenoid while in the neutral position to cause vibration of the magnetic flapper and further assist in removing debris
Data Source
Figure 1A
Figure 1B~1D
Figure 2
AI summary
A valve system is provided that includes an electromechanical solenoid, a gas valve including a magnetic flapper, a power source in electrical communication with the electromechanical solenoid, and a controller. The controller is configured to control the power source to supply an intermediate voltage that causes the electromechanical solenoid to move to a neutral position between a default position and a fully-actuated position. In so doing, the magnetic flapper is maintained in a neutral position between two gas ports and a flow of gas between the ports can be used to clean foreign particles from the magnetic flapper. The controller can also provide a varying voltage to the electromechanical solenoid while in the neutral position to cause vibration of the magnetic flapper and further assist in removing foreign particles. A closed loop system including a feedback circuit can be used for adjusting the voltage applied to the solenoid based on pressure sensed.