In the biopharmaceutical and fermentation industries, the precision of process control of bioreactors, as the core equipment, directly affects product quality and production efficiency. And gas flow control, especially precise measurement and regulation of gases such as oxygen and carbon dioxide in the intake, is a key factor affecting cell growth metabolism and product synthesis. Aituoli（Aitoly）Gas flow meters provide reliable technical support for such applications due to their high precision, stability, and excellent anti-interference ability.

1 Why do bioreactors require precise gas flow control

A bioreactor (also known as a fermentation tank) is a dynamic and living system used for cultivating microorganisms, animals, or human cells. Cells continuously consume nutrients, excrete metabolic waste, and respond to environmental changes throughout the entire processpHExtremely sensitive to dissolved oxygen.

Dissolved oxygen（DO）Accurate control: In most aerobic fermentation processes, oxygen is an essential substance for cells to carry out aerobic respiration and synthesize target products. However, the solubility of oxygen in water is very low, and as cell density increases, dissolved oxygen quickly becomes a limiting factor, leading to metabolic arrest or cell death. Therefore, it is necessary to precisely control the flow rate of air or oxygen introduced according to the different stages of cell growth to maintain dissolved oxygen levels. Related studies have shown thatBioFlo 110In biological reaction systems, precise control of the intake rate is to ensure that dissolved oxygen is maintained at a set level (such as30%The key is saturation.

pHStable maintenance of values: Many cell culture processes require stabilitypHenvironment The introduced carbon dioxide gas is not only used as a carbon source for certain cells, but also more commonly used to neutralize the alkaline substances produced by metabolism, and precisely regulate them by interacting with the carbonate buffer systempHValue.

Removal and process monitoring of metabolic waste: carbon dioxide produced by cellular respiration The rate of gas release is an important indicator reflecting the metabolic activity of cells. By monitoring the flow rate and composition of incoming and outgoing gases, the growth status of cells can be estimated in real time, providing a basis for process optimization and control.

II How to achieve the accuracy of Etuoli gas flowmeter

Under the umbrella of AtolliMFM330Gas mass flowmeter andMFC330The technical design of thermal products such as gas mass flow controllers fully meets the stringent requirements for gas flow measurement in bioreactors.

1. Core working principle and advantages

The Aituoli gas flowmeter adopts the principle of thermal mass flow measurement. This principle directly measures the ability of a gas to carry away heat, thereby calculating the mass flow rate of the gas. Compared with traditional flow meters based on volume measurement, this has significant advantages:

Directly measuring mass flow without temperature and pressure compensation: avoids measurement errors caused by gas temperature and pressure fluctuations, and provides more direct and accurate measurement results.

High precision and high repeatability: toMFM330For example, its accuracy can reach ±0.5% F.S.(Full range), with a repeatability accuracy of up to ±0.2% F.S.This is crucial for biological processes that require precise control of gas ratios.

Wide traffic range: Traffic specifications cover from micro upgrades0-5 SCCMTo high traffic0-50 SLPMCan adapt to different scale requirements from laboratory small-scale reactors to pilot production.

Fast response capability: Sensor response time less than1In seconds, it can quickly respond to dissolved oxygen fluctuations caused by changes in cellular metabolism within the bioreactor, enabling the control system to adjust in a timely manner.

2. Key technical characteristics for biological applications

Built in temperature and pressure sensors: further improving the comprehensive accuracy and reliability of measurement.

Multiple communication interfaces: supportRS232TheCANTheRS485The4-20mAThe0-5VMultiple communication methods such as analog signals can be easily integrated into the automation control system of biological reactors (such as...)BioFlo 110/320usedLabVIEWImplement remote monitoring and automatic adjustment in the system.

Excellent material compatibility: Air contact components are usually made ofSUS316LStainless steel, with fluororubber seals. These materials have good biocompatibility and corrosion resistance, can meet the requirements of sterile environments, and can tolerate various gases that may be used during the cultivation process.

No movable parts: Designed to be sturdy, reducing failure rates and minimizing maintenance requirements.

III Typical application scenarios on bioreactors

In actual biological processes, the Etuoli gas flowmeter/The controller plays multiple roles:

Accurate control of air flow: in aerobic fermentation (such asGibberellic AcidIn batch fermentation, automatic adjustment is made based on the feedback signal from the dissolved oxygen electrodeMFM/MFCAdjust the valve opening and change the air flow rate (e.g. from initial)0.5 SLPMupgrade to1 SLPM）To maintain the set dissolved oxygen level.

Mixing and regulation of oxygen, nitrogen, and carbon dioxide:

In high-density cell culture, if air cannot meet the demand for dissolved oxygen, pure oxygen needs to be supplemented. The flow meter can accurately control the oxygen mixing ratio.

In need of controlpHAccurately inject carbon dioxide.

Accurately control the nitrogen flow rate to create an anaerobic environment during anaerobic fermentation or when oxygen needs to be expelled.

Process analysis and optimization: By accurately recording the cumulative consumption of various gases throughout the entire process, combined with exhaust gas analysis, the oxygen uptake rate can be calculated（OUR）And carbon dioxide release rate（CER）Provide data support for optimizing process formulas and scaling up production based on key physiological parameters.

4 Application examples and effects

In an article about magnetic snail bacteria（M. gryphiswaldense）In the study of producing magnetic particles, researchers used an integrated gas control systemBioFlo 110Fermentation tank. Process control display, initial set air flow rate is0.5 SLPMWhen the dissolved oxygen decreases to15%When, the system increases the air flow to1 SLPMSubsequently, the dissolved oxygen was precisely maintained at a certain level by adjusting the stirring speed0-1%To meet the special microaerophilic environmental requirements of this strain within an extremely low range. This precise programming and stable control of ventilation is the cornerstone for successfully achieving high-density cultivation and efficient product synthesis. The Etuoli gas flowmeter plays a crucial role in ensuring precise and on-demand gas input in such applications.

summary

The Aituoli gas flowmeter, with its high precision, fast response, and stability brought by its thermal mass flow measurement technology, meets the core requirements of modern bioreactors for gas flow control. It precisely regulates dissolved oxygenpHThe precise application of stable maintenance and process metabolism monitoring not only ensures the repeatability and reliability of biological processes, but also provides important technical support for promoting efficient production and process optimization in fields such as biopharmaceuticals, food fermentation, and bioenergy.