Single-Use Flexible Sparger Layering for Uniform Bubbles and Low Shear
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Solution Overview
Problem
Conventional sparging devices for bioreactors face challenges in balancing bubble size, shear, foaming, and air distribution, leading to undesirable bioprocess product losses and cell death, while existing disposable spargers are bulky, expensive, or ineffective in distributing gas uniformly.
Innovation Solution
A multi-layered flexible sparger with three film layers and two mesh layers, featuring controlled hole sizes and orientations to achieve uniform bubble size and distribution, independent of orientation, and integrated with microprocessor-controlled bioreactors for optimal kLa and cell density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high gas flow rates are used to achieve high kLa, then oxygen transfer capacity is improved, but cell shear increases and cell death occurs
Solution Approach 1:
The sparger is divided into multiple layers with different hole size distributions. The first layer has larger holes while the second layer has smaller holes, allowing the system to achieve high kLa through controlled gas distribution without creating uniformly small bubbles that cause excessive shear. This segmentation enables different regions to serve different functional purposes.
Solution Approach 2:
Different regions of the sparger have different local properties - the first layer provides coarse aeration with larger bubbles while the second layer provides fine aeration with smaller bubbles. This local differentiation allows the system to optimize both oxygen transfer and shear control by having each region contribute differently to the overall gas distribution.
2Quantity of substance
If small bubbles are created to increase gas transfer surface area, then kLa is improved, but cell damage increases due to similar size to cells
Solution Approach 1:
The sparger structure segments the gas flow into two distinct bubble size populations through its multi-layer design. The first layer creates larger, safer bubbles while the second layer creates smaller, high-transfer bubbles, ensuring that not all bubbles are cell-damagingly small.
Solution Approach 2:
The sparger combines different functional characteristics in a composite structure - the first layer provides mechanical cushioning with larger bubbles while the second layer provides high surface area transfer with smaller bubbles. This composite approach creates a balanced bubble size distribution that optimizes both transfer and safety.
3Productivity
If conventional spargers are used to distribute gas, then aeration is achieved, but uniform distribution is not obtained and leakage occurs
Solution Approach 1:
The sparger is segmented into multiple layers with progressively smaller holes, creating a staged gas distribution system. This segmentation ensures uniform distribution by progressively breaking down gas flow through controlled resistance at each layer, preventing channeling and leakage while maintaining aeration efficiency.
Solution Approach 2:
The sparger utilizes parameter changes in hole size across different layers to control gas flow characteristics. By progressively reducing hole size from the first to second layer, the system maintains consistent pressure drop and flow distribution, ensuring uniform gas release without leakage while preserving aeration performance.
4Manufacturing precision
If molded spargers are used to control bubble size, then bubble distribution is improved, but device complexity and cost increase
Solution Approach 1:
Instead of using a complex molded structure, the invention segments the sparger into simple, stacked layers with progressively smaller holes. This segmentation achieves precise bubble size control through a straightforward layered architecture rather than complex molding, reducing manufacturing complexity while maintaining precision.
Solution Approach 2:
The sparger achieves bubble size control through parameter changes in hole diameter across simple layers rather than through complex molded geometries. By varying hole size in a systematic way across multiple simple layers, the system achieves precise bubble distribution with minimal structural complexity and lower manufacturing cost.
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 sparger design ensures consistent bubble size and gas distribution, enhancing cell viability and process efficiency by maintaining a homogeneous environment, supporting high kLa and scalability across various bioreactor sizes.
Implementation Method 1
The containers also can contain one or more aeration devices, e.g., gas spargers, through which gas bubbles are introduced into the container contents
Implementation Method 2
gas bubbles are introduced into the container contents
Implementation Method 3
the first layer has a higher back pressure than the second layer, which creates a more uniform distribution of gas flow
Implementation Method 4
Because of the pressure of 50-5000 liters of fluid, spargers must have check valves or use high pressures to create the back pressure necessary to prevent liquids from back flowing into the sparger during aeration
Implementation Method 5
mass transfer from the gas-liquid phase or vice versa is sufficient for the process
Implementation Method 6
Aeration of biological fluids within bioreactors is common to support cell culture oxygenation via sparging devices
Implementation Method 7
Another prior art flexible sparger, comprising two film layers lacked an even distribution of air
Data Source
Figure 1~3
Figure 4
Figure 5~6
AI summary
A multi-layered flexible sparger (100) that has a bottom film layer (102), a middle film layer (106), and a top film layer (110); a first inner mesh (104) disposed between the bottom film layer and the middle film layer; a second inner mesh (114) disposed between the middle film layer and the top film layer; and a port capable of delivering a gas to the multi-layered flexible sparger disposed between the top film layer and the bottom film layer, wherein the middle film layer comprises drill holes and the top film layer comprises drill holes.