Fluidic Oscillator Bubble Generation for Aeration Efficiency
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Solution Overview
Problem
Existing methods for generating fine bubbles in liquids face challenges such as instability in bubble formation, energy inefficiency, and coalescence, which hinder the efficient dissolution of gases and transportation of fluids, particularly in applications like sewage treatment and yeast manufacturing.
Innovation Solution
A method involving a gas source under pressure, with a conduit opening into the liquid, where the gas is oscillated at frequencies between 1 and 100 Hz without oscillating the conduit, using a fluidic oscillator to create small bubbles of 0.03 to 2 mm in diameter with minimal backflow, employing a diverter to control flow between paths and adjust oscillation frequency for optimal bubble size and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the aperture size is reduced to produce smaller bubbles, then bubble dissolution efficiency is improved, but the energy required to overcome friction and produce bubbles increases
Solution Approach 1:
The patent applies periodic oscillation to the gas flow at frequencies between 1-100 Hz, creating cyclic pressure variations that facilitate bubble detachment at smaller sizes. This periodic action allows bubbles to be released before they grow too large, reducing the energy needed to overcome friction in the aperture while maintaining high dissolution efficiency.
Solution Approach 2:
The system transitions from static bubble formation to dynamic oscillating flow, where the gas flow rate and pressure are continuously varied. This dynamic approach enables control over bubble size and detachment timing, allowing optimal balance between aperture friction energy loss and bubble dissolution efficiency.
2Productivity
If gas pressure is increased to detach bubbles from the aperture, then bubble production rate is improved, but energy consumption increases and bubble size becomes uncontrolled
Solution Approach 1:
By oscillating the gas flow periodically, the system achieves bubble detachment through cyclic pressure changes rather than sustained high pressure. This allows bubble production to continue at high rates while average energy consumption is reduced, as pressure is applied intermittently rather than continuously.
Solution Approach 2:
The dynamic oscillation of gas pressure creates controlled variations in bubble formation and detachment. This dynamic control prevents uncontrolled bubble growth while maintaining high production rates, as the oscillating flow rhythmically pinches off bubbles at desired sizes without requiring continuously elevated pressure.
3Productivity
If multiple bubbles grow in parallel from a common pressure source, then bubble production capacity is improved, but instability causes uneven bubble sizes and coalescence
Solution Approach 1:
The oscillating gas flow creates synchronized periodic detachment of bubbles from multiple apertures. This periodic action ensures that bubbles are released at regular intervals in a coordinated manner, preventing the instability that occurs with continuous flow where slight variations cause runaway growth differences and coalescence.
Solution Approach 2:
Dynamic oscillation of the gas supply creates controlled variations that stabilize bubble growth across multiple parallel apertures. The oscillating flow rhythmically equalizes pressure distribution, ensuring uniform bubble sizes are achieved simultaneously from all apertures, preventing the size differential that leads to coalescence.
4Ease of operation
If bubbles are allowed to grow beyond hemispherical size, then easier detachment is achieved, but bubble size increases and dissolution efficiency decreases
Solution Approach 1:
The periodic oscillation creates rhythmic pressure changes that facilitate bubble detachment at smaller sizes. The oscillating flow periodically reduces surface tension and applies shear forces that enable bubbles to detach while still relatively small, maintaining high dissolution efficiency without requiring bubbles to grow to large hemispherical sizes.
Solution Approach 2:
Dynamic oscillation of the gas flow creates varying forces during bubble growth that promote detachment at optimal sizes. The dynamic pressure variations and flow oscillations apply mechanical forces to growing bubbles that facilitate release before they become too large, balancing detachment ease with dissolution efficiency.
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
This approach enhances the efficiency of bubble generation by minimizing energy waste, stabilizing bubble size, and reducing coalescence, resulting in consistent, small-sized bubbles that improve gas dissolution and fluid transport efficiency in various industrial applications.
Implementation Method 1
oscillating the gas passing along the conduit without oscillating the conduit, other than by any reaction of the oscillating gas, said oscillation being at a frequency between 1 and 100 Hz
Implementation Method 2
the gas pressure inside the bubble is relatively much higher than in a large bubble, so that the gas dissolves more rapidly
Implementation Method 3
the surface tension of a small bubble means that the gas pressure inside the bubble is relatively much higher than in a large bubble
Implementation Method 4
oscillating the gas passing along the conduit... stabilizing bubble size, and reducing coalescence
Data Source
AI summary
A method of producing small bubbles (90) of gas in a liquid comprises a source (16) of the gas under pressure, a conduit (64a) opening into a liquid and oscillating the gas passing along the conduit at a frequency between 1 and 100 Hz. The oscillation is effected by fluidic oscillator (10) comprising a diverter that divides the supply into respect outputs (A, B), each output being controlled by a control port, wherein the control ports are interconnected by a closed loop (22). There may be at least two of said conduits (62a, 64a), each output port being connected to one or the other of said conduits, in which one phase of the oscillating gas is employed to drive liquid across the conduit (64a) after formation of a bubble in the other phase of oscillation, whereby the bubble is detached by the force of said driven liquid.