The Highly Effective Airlift Fermenter: Principles and Purposes

Airlift fermenter is a new type of biological fermenter that began to develop and applied at the end of the last century. The informal mixing structure of this device can minimize the yield of bacteria, and also reduce the mechanical shear power， especially for various fungi of the mycelium. The gas -improved gas -liquid hybrid has greatly improved the transmission and utilization of oxygen, which is especially suitable for high viscosity medium and products with high soluble oxygen.

The airlift bioreactor can also design two cycle methods: internal circulation and external circulation according to the user requirements. It can also be derived from design and manufacturing light bioreactors, which are widely used in the cultivation of optical bacteria and algae. This article mainly takes you to understand the characteristics, working principles and various purposes of the airlift fermenter.

1. The characteristics of airlift fermenter

• Compared with mechanical stirring fermentation tanks, airlift fermenter can save 70%-80% of electricity and reduce production costs.
• Airlift fermenterhas no sealing device, no leakage, and there is no dead area in the equipment. The sterilization is completely reduced. The opportunity of the bacteria is greatly reduced, and the reliability of sterile operation is high.
• The high efficiency of airlift fermenterand oxygen transmission efficiency can meet the fermentation production of various oxygen microorganisms in any region and season.
• The mechanical shear force of airlift fermenterhas less damage to microorganisms. In addition, its dissolved oxygen is sufficient and timely removed, providing a good growth environment for microorganisms, which can effectively promote metabolism, accelerate product accumulation , Increase the production rate and conversion rate of the product.
• The airlift fermenteris easier to achieve large -scale and automated compared to other fermentation tanks. The volume of the equipment can be from 20L to 200kl. There is no difficulty in manufacturing, installation, operation and maintenance. The control factors of the equipment are also less than the mixing tank, which is easy to achieve automated control.
• Airlift fermenteralso has the characteristics of small work noise, high installation coefficients, and basically no maintenance.

 

Of course, no biological fermenter is perfect, and there are some disadvantages:

• Due to the impact of the tank structure of the airlift fermenteritself, the air throughput required for work is very large.
• Compared with the mechanical stirring fermenter, the mixing and contact of airlift fermenteris poor.For high -viscosity fermentation products, it cannot effectively ensure that the gas fluid is mixed evenly.
• When the organic body and operating conditions of the cycle change, the amount of substrates, nutrients and oxygen cannot be consistent;
• Mixing and ventilation are the problem of coupling, that is, it is difficult to improve the mixed situation without changing the ventilation.

Therefore, in combination with the case of many years of biological fermenter reconstruction case, we believe that the new type of air lift fermenter is suitable for the use of short fat type, and it is advisable to control the height of the straight barrels below 16m. Energy consumption of gas system; at the same time, a new type of energy-saving air-saving air-saving device-gas liquid rotation flow mixture is used to increase the soluble oxygen in the fermented tank.In this way, the air lift fermenter can be used to its fullest potential.

2. The working principle of airlift fermenter

There are many types of airlift bioreactor. Common airlift circulation, bubble, air jet type, etc. The circular air lift fermenter is divided into internal circulation and external circulation. The biological fermenter industry has been used in large quantities of airlift fermenter including gas -lifted internal circulation fermentation tanks, gas -liquid dual jet gas -luminous fermentation tanks, and tower -rising fermentation tanks with multiple layers of distributed boards. The bubbling tank is the most primitive ventilation fermentation tank. Of course, there is no diversion barrel in the bubble reactor, so the main orientation flow of the liquid is not controlled.

To put it simply,the working principle of the airlift bioreactor is to spray the sterile air through the air distribution device in the fermented fermentation solution. The fermentation solution with a small gas content sinks, forming a circular flow to achieve mixed and dissolved oxygen.

3. The purpose of air lift fermenter

Airlift bioreactors are tower reactors for large-scale aerobic cultures where the mixing of the culture broth is done by the inserted gas via an airlift pump.The application of airlift fermenter has a long history. This device can be widely used in antibiotics, amino acids, enzymes, vitamins, organic acids and other oxygen fermentation processes.

At present, airlift bioreactor are mainly used in the country for the production of glutamic acid, antibiotics, olee, glycated enzymes, and citric acid. The equipment volume has reached 140,000L. After being put into use, it has achieved very significant economic benefits. The air necessary for fermentation flows in the inside and outside of the static hybrid component, driving the fermentation liquid circulation, and promoting the gas-liquid charging and mixing.

In terms of chemicals, airlift fermenters can be used for air-liquid, gas-liquid-solid reaction process.

In terms of environmental protection, it can be used for sewage treatment.

4.Classification of airlift fermenters

(1) Glass airlift fermenter
Glass-based airlift fermenters are widely used in microbiology laboratories of scientific research institutes and enterprises, and are an ideal tool for precision fermentation testing. It can be applied to the screening of medium formulations for biological fermentation culture, the optimization of fermentation process parameters, and the verification of production processes and strains.
Specifications are usually: 5L, 7L, 10L; Air flow agitation, small shear force; The observation is clear; It is suitable for microbial reactions with microbial cells as the purpose product, macrofungal fermentation, and can also be used for some microbial metabolic reactions that do not require high dissolved oxygen. There are two alternative structural forms: internal circulation and external circulation.

 

(2) Stainless steel airlift fermenter
Unlike glass fermenters, stainless steel fermenters are usually more complex in structure and are widely used in large-scale industrial production, such as pharmaceutical, food, chemical and other fields. Suitable for all types of fermentation processes, including aerobic and anaerobic fermentation. It can meet the requirements of different fermentation processes, and can carry out the cultivation of a variety of microorganisms and the production of metabolites.

(3) Industrial airlift fermenter
The industrial airlift fermenter is a kind of bioreactor widely used in large-scale industrial fermentation production, and in the pharmaceutical industry, it is used to produce antibiotics, vaccines, biological drugs, etc.; In the food and beverage industry, it can be used for fermentation to produce amino acids, vitamins, enzyme preparations, alcohol, etc.; In the chemical industry, it is used for the production of organic acids, biopolymers, etc. For example, glutamate fermentation, penicillin fermentation, etc., are commonly used in airlift fermenters for large-scale production.

 

For the current society with a strong concept of “energy conservation”, coupled with the rapid development of the fermentation industry, the airlift fermenter will gradually become the “king of the tank” of the biological fermenter. Because of its simple structure, easy to manufacture, simple operation and maintenance, there is a high solution -oxygen rate and soluble oxygen efficiency, good heat transfer, small shear force, low damage to biological cells, low power consumption, etc. It can bring more profits to the fermentation industry.

 

However, the time of cycling in the circular pipe in the circular pipe needs to be determined according to the type of microorganisms trained and the rate of oxygen consumption. If it is not controlled properly, it will seriously affect the vitality of microorganisms and reduce the production rate of fermentation.

Therefore, we will continue to explore the structure of optimizing the air lift fermenter, in order to look forward to better of it into the market, bringing more surprises to the biological fermenter industry.