高效气升式发酵罐：原理和用途

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. 气升式发酵罐的特点

• 气升式发酵罐与机械搅拌发酵罐相比，可节省电力70%-80%，降低生产成本。
• 气升式发酵罐无密封装置，无泄漏，设备无死区，灭菌彻底，细菌滋生的机会大大减少，无菌操作可靠性高。
• 气升式发酵罐效率高，输氧效率高，可满足任何地域、季节各种需氧微生物的发酵生产。
• 气升式发酵罐的机械剪切力对微生物的损伤较小，加之其溶解氧充足且及时除去，为微生物提供了良好的生长环境，能有效促进新陈代谢，加速产品的积累，提高产品的生产率和转化率。
• 气升式发酵罐相对于其他发酵罐更容易实现大型化、自动化，设备容积可以从20L到200kl，制造、安装、操作、维护等都没有什么难度，设备的控制因素也比搅拌罐少，容易实现自动化控制。
• 气升式发酵罐还具有工作噪音小、安装系数高、基本免维护等特点。

 

当然，没有一种生物发酵罐是完美的，也存在一些缺点：

• 气升式发酵罐由于受罐体结构本身的影响，工作时所需的空气通量很大。
• 与机械搅拌发酵罐相比，气升式发酵罐的混合、接触性较差，对于高粘度的发酵产物，不能有效保证气液混合均匀。
• 当循环的有机体和运行条件发生变化时，底物、营养物和氧气的量不能保持一致；
• 混合与通风是耦合问题，即不改变通风就很难改善混合情况。

因此结合多年生物发酵罐改造案例，我们认为新型气升式发酵罐宜采用矮肥型，直桶高度控制在16m以下为宜，这样可以降低气系统能耗；同时采用新型节能节气节气装置—气液旋流混合器，增加发酵罐内溶解氧，这样可以最大程度地发挥气升式发酵罐的潜力。

2. 气升式发酵罐的工作原理

气升式生物反应器的类型很多，常见的有气升式循环、鼓泡式、气流喷射式等。循环式气升发酵罐又分为内循环和外循环。生物发酵罐工业上已大量采用的气升式发酵罐有气升式内循环发酵罐、气液双喷射气升式发酵罐、多层分布板的塔式升发酵罐等。鼓泡罐是最原始的通风发酵罐，当然鼓泡式反应器内没有导流桶，所以液体的主要导向流是不受控制的。

简单来说，气升式生物反应器的工作原理就是将无菌空气通过空气分布装置喷入正在发酵的发酵液中，含气量少的发酵液下沉，形成循环流动，达到混合、溶氧的目的。

3. 气升发酵罐的用途

气升式生物反应器是用于大规模需氧培养的塔式反应器，其中培养液的混合是通过气升泵插入的气体完成的。气升式发酵罐的应用历史悠久，该装置可广泛应用于抗生素、氨基酸、酶、维生素、有机酸等有氧发酵工艺。

目前气升式生物反应器在国内主要用于谷氨酸、抗生素、油酸、糖化酶、柠檬酸等生产，设备容积已达14万L，投入使用后取得了十分显著的经济效益，发酵所需的空气在静态混合组件内外流动，带动发酵液循环，促进气液的充注和混合。

在化学品方面，气升式发酵罐可用于气-液、气-液-固反应过程。

在环保方面，可以用于污水处理。

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.

 

但在循环管内循环的时间需要根据所培养微生物的种类及耗氧速率来确定，若控制不当，会严重影响微生物的活力，降低发酵的生产率。

因此，我们将继续探索优化气升式发酵罐的结构，以期待更好的气升式发酵罐投入市场，给生物发酵罐行业带来更多的惊喜。