Oxygen Concentrator Check Valves Prevent Reverse Flow
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Solution Overview
Problem
In oxygen concentrators using a PSA system, there is a temporary reverse flow of exhaust air into the sieve bed generating oxygen due to pressure drops and pilot flow channel layout issues during switching between sieve beds.
Innovation Solution
Incorporating check valves in the air supply flow channels upstream of the air supply valves to prevent reverse flow, with a pilot air supply system that includes a diaphragm valve and electromagnetic pilot valve, and a manifold base configuration that allows flexible pilot flow channel layout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the pilot flow channel is branched from the air supply flow channel, then the electromagnetic pilot valve can be supplied with pilot air, but the pilot pressure drops temporarily when switching sieve beds causing reverse flow of exhaust air
Solution Approach 1:
A check valve is introduced as an intermediary component in the air supply flow channel between the air supply valves and sieve beds. This check valve prevents the reverse flow of exhaust air into the oxygen-generating sieve bed by allowing air to flow only in the forward direction (from air supply to sieve bed), thus resolving the reliability issue caused by temporary pilot pressure drops during switching operations.
2Reliability
If check valves are added to prevent reverse flow, then air flow integrity is maintained, but device complexity increases
Solution Approach 1:
Instead of adding complex control systems throughout the valve assembly, the check valve is placed locally at the critical position where reverse flow occurs (in the air supply flow channel between air supply valves and sieve beds). This localized solution addresses the specific reverse flow problem without requiring complex modifications to the entire valve system, thus minimizing the increase in device complexity.
3Productivity
If the air supply valve is closed during switching, then oxygen generation is maintained, but exhaust air may flow reversely due to pressure imbalance
Solution Approach 1:
The check valve is pre-installed in the air supply flow channel to provide preliminary protection against reverse flow. When the air supply valve closes during switching, the check valve is already in place to prevent exhaust air from flowing reversely into the oxygen-generating sieve bed, thus maintaining both oxygen generation continuity and preventing harmful reverse flow without requiring additional control actions.
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
Prevents reverse flow of exhaust air into the oxygen-generating sieve bed, ensuring continuous high-concentration oxygen production by maintaining air flow integrity during sieve bed switching.
Implementation Method 1
a configuration of a PSA (Pressure Swing Adsorption) system using an absorbing material (zeolite) having properties such as selectively adsorbing nitrogen under increased pressure
Implementation Method 2
first and second check valves configured to prevent a reverse flow are provided respectively at positions in the first and second branch flow channels on the upstream sides of the first and second air supply valves
Data Source
AI summary
Branch flow channels configured respectively to supply compressed air to two sieve beds respectively are provided with air supply valves each including a diaphragm valve and an electromagnetic pilot valve for driving the diaphragm valve and configured to open and close the respective branch flow channels, a pilot flow channel configured to supply pilot air to the electromagnetic pilot valves is branched from the branch flow channels, and check valves for preventing reverse flows in the respective branch flow channels are provided.