In the fermentation industry, fermenters are often used as vessels for research or production process trials.Usually, fermenters are divided into several types such as cylindrical, flat-bottomed, slanted-bottomed and flat-bottomed. For different types of fermenters, the bottom structure is also different.

Cylindrical fermenter
Cylindrical fermenter is developed on the basis of cylindrical container. Its basic structure is cylindrical, and the thickness of the cylinder has different designs according to the usage requirements.Cylindrical vessels can be divided into: small, medium and large according to its diameter; according to its volume: 500L ~ 1000L, 2000L ~ 5000L and 10,000L ~ 50,000L; according to its pressure is divided into: atmospheric pressure and reduced pressure.
This type of fermenter is suitable for large and middle-scale fermentation production, and can also be used in the process of sterilizing liquids or gases.

Flat-bottomed fermenter
In a flat-bottomed fermenter, microorganisms are able to grow and multiply both on the bottom of the vessel in contact with the liquid and on the walls.This type of fermentation is best suited for fermenters employing microorganisms as the culture medium. However, it is less effective in separating yeast and solid impurities.Therefore, for this type of fermentation, it is necessary to take certain measures to improve the contact conditions at the interface between the solid particles and the liquid, so as to ensure that the solid particles can spread evenly in the liquid.In order to improve the mass transfer rate of microorganisms in the vessel, it is also possible to increase the gas-liquid contact area by means of a bottom setup, i.e., an aeration device.

Slant bottom fermenter
The bottom of a slanted-bottom fermenter creates a fluid flow through the vessel walls at an inclined angle.The advantage is that there is no support structure inside the vessel, which is easy to operate and can meet the requirements of microbial growth and product synthesis in the fermentation process. However, its mechanical strength is lower than that of flat-bottomed fermenter.
At present, the slant-bottom fermenter is widely used in the fermentation industry. It is suitable for a variety of fermentation process tests and research in the production process.