Reciprocating Stirrer with Porous Sparger for Microbubble Generation

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Solution Overview

Problem

Conventional vertically reciprocating stirring apparatuses cannot effectively break down gas bubbles such as oxygen or carbon dioxide into smaller sizes for efficient absorption in culture solutions, leading to inadequate gas dissolving and absorption.

Innovation Solution

A reciprocating stirring apparatus equipped with a micro bubble generating device featuring a porous sparger that produces fine bubbles through pores, combined with a stirring blade for vertical reciprocation, ensuring effective gas dissolution and minimal cell damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a conventional sparger is used to supply gas to the culture solution, then gas can be supplied, but the bubbles cannot be made smaller (broken up) by the stirring blade due to low shearing action, resulting in inadequate gas absorption

Engineering Contradiction:

Improvegas absorption efficiencyVSAvoidbubble size

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent employs a porous sparger body with multiple pores to generate microbubbles directly at the gas-liquid interface. The porous structure breaks the gas flow into numerous small bubbles before they enter the culture solution, achieving fine bubble generation without requiring high shearing action from the stirring blade. This directly addresses the problem of inadequate gas absorption by increasing the total surface area of bubbles available for dissolution.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent changes the physical parameter of bubble size by using a porous sparger with controlled pore dimensions. By adjusting the pore size and distribution in the sparger body, the system generates bubbles of optimal size for efficient gas absorption. This parameter change allows the system to achieve fine bubble generation without increasing mechanical shearing force, thus maintaining cell safety while improving gas absorption efficiency.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If a vertically reciprocating stirring blade is used to stir the culture solution, then gentle stirring with low shearing action is achieved suitable for cells, but bubbles cannot be broken up into smaller sizes

Engineering Contradiction:

Improvecell damageVSAvoidgas dissolution rate

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent applies preliminary action by generating fine bubbles at the source (sparger) before they enter the culture solution. Instead of relying on the stirring blade to break up large bubbles afterward, the system pre-conditions the gas by passing it through the porous sparger structure, which creates microbubbles in advance. This preliminary bubble size reduction occurs without requiring high shearing action, thus protecting cells from damage while ensuring efficient gas dissolution.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent substitutes the mechanical shearing action of the stirring blade with a structural mechanism (porous sparger) that physically breaks gas into small bubbles through its pore architecture. This replacement eliminates the need for high-intensity mechanical mixing to achieve fine bubble generation, allowing the use of gentle reciprocating stirring that is safe for cells while still achieving efficient gas absorption through the microbubble structure.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 apparatus efficiently generates and maintains micro bubbles for rapid gas dissolution and prolonged contact with the culture solution, enhancing gas absorption without damaging cells, even with larger bubbles, and maintains a favorable vertical flow.

Implementation Method 1

a sparger constituted by a porous body having a cavity portion inside and gas supply means for supplying gas to the cavity portion in which the gas supplied by the gas supply means to the cavity portion is made to generate bubbles in the article to be stirred through pores of the porous body

Methodology Applied

Scientific EffectPorosity: Porosity

Implementation Method 2

The vertically reciprocating stirring apparatus can gently stir the culture solution by a low shearing action and favorably stir it and thus, it is suitable for stirring the culture solution containing cells and the like susceptible to damage

Methodology Applied

Scientific EffectShear stress: Shear Stress

Implementation Method 3

the gas such as oxygen or carbon dioxide or the like is rapidly dissolved into the culture solution

Methodology Applied

Scientific EffectGas absorption: Absorption (physical)

Data Source

PatentUS10799841B2Reciprocating stirring apparatus having micro bubble generating device

Publication Date: 2020.10.13 JGC CORP

AI summary

A reciprocating stirrer device with which favorable gas absorption into the stirred substance can be obtained. The reciprocating stirrer device is obtained from: a stirring vessel in which the substance to be stirred is placed; a reciprocating drive shaft provided inside the stirring vessel; a stirring blade connected and affixed so as to intersect the drive shaft; and a microbubble-generating unit. The microbubble-generating unit is obtained from a sparger that is made of a porous body and a gas supply means for supplying a gas to the sparger. Bubbles are generated in the substance being stirred by passing gas supplied to the sparger by the gas supply means through pores of the porous body.