Intermittent Gas Sparger for Membrane Fouling Control
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Solution Overview
Problem
Existing gas sparging systems for membrane filtration face challenges in inhibiting fouling while avoiding pressure spikes, as they require high energy to create large bubbles that can break up fouling films but also lead to undesirable pressure fluctuations.
Innovation Solution
A gas sparger apparatus that produces intermittent bursts of large bubbles even with continuous gas flow, integrated with membrane modules, using a potting head and conduit system to manage gas release and distribution, ensuring discrete bubble flow without constant pressure spikes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high gas flow rate is used to create large bubbles for breaking up fouling films, then fouling inhibition is improved, but pressure spikes and energy consumption increase
Solution Approach 1:
The patent implements periodic gas flow bursts instead of continuous high flow. Gas is supplied in intermittent cycles with high flow duration set to 1-10 seconds and low flow duration set to 1-60 seconds, creating periodic large bubbles that effectively break fouling films while allowing pressure to recover between bursts, thereby reducing overall energy consumption compared to continuous high flow
Solution Approach 2:
The patent accumulates gas in a reservoir before releasing it in controlled bursts. This preliminary accumulation allows the system to build up sufficient gas volume to create large bubbles when needed, rather than requiring continuous high energy input to maintain constant large bubble generation, thus reducing overall energy requirements while maintaining fouling inhibition effectiveness
2Reliability
If high gas flow rate is used to create large bubbles for breaking up fouling films, then fouling inhibition is improved, but pressure spikes occur
Solution Approach 1:
The patent uses periodic gas flow cycles where high flow is alternated with low flow periods. During low flow periods (1-60 seconds), pressure has time to equalize and spikes are avoided. This periodic modulation maintains the ability to create large bubbles for fouling breakdown while preventing the continuous pressure elevation that would cause harmful spikes
Solution Approach 2:
The patent incorporates a gas reservoir that cushions pressure fluctuations. The reservoir accumulates gas during low flow periods and releases it during high flow periods, acting as a buffer that smooths out pressure spikes. This beforehand cushioning allows large bubbles to be formed without transmitting excessive pressure shocks through the system
3Stability of the object's composition
If continuous gas flow is used, then steady aeration is maintained, but large bubble formation for fouling breakdown is reduced
Solution Approach 1:
The patent implements periodic gas flow with alternating high and low flow periods. During high flow periods (1-10 seconds), large bubbles are generated to break up fouling films. During low flow periods (1-60 seconds), the system maintains baseline aeration stability. This periodic cycling combines the benefits of both continuous steady flow and intermittent burst flow
4Reliability
If rapid valve movements are used to create large bubbles, then fouling inhibition is improved, but undesirable pressure spikes are generated
Solution Approach 1:
The patent uses periodic valve operation to control gas flow bursts. Instead of rapid on/off switching that causes pressure spikes, the valve opens for extended high flow periods (1-10 seconds) followed by longer low flow periods (1-60 seconds). This slower, more gradual periodic modulation allows pressure to equalize between bursts, reducing spikes while still creating large bubbles for fouling inhibition
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
Effectively inhibits membrane fouling by creating transient flow conditions that reduce energy consumption and pressure spikes, allowing for efficient removal of foulants while maintaining consistent operation.
Implementation Method 1
A sparger (10) receives a flow of gas (32) from a distribution pipe (18). The sparger (10) has a housing (12) open at a bottom and having a top defining an open top end of a discharge conduit (22). The discharge conduit (22) has a first outlet (24) in communication with an area inside and near the top of the housing (12) and a second outlet (26) open to the outside of the housing (12).
Implementation Method 2
Optionally, a cover or diffuser above the potting head and over an outlet from the conduit may direct the released gas or break up the released gas into smaller (though still large) bubbles or both.
Data Source
Figure 1A~1D
Figure 2
AI summary
A gas sparger produces an intermittent flow of bubbles even if provided with a continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. The housing is integrated with the potting head of a module. The conduit passes through the potting head.