Bacteria, fungi and enzymes help produce pharmaceuticals, for example penicillin. Fermentation is used to modify starch, preserve food, polymerize environmentally friendly plastics, purify rare earths, produce alcohol, biogas, cheese, yogurt, yeast, baking dough or vinegar. Tea, coffee and tobacco are refined by fermentation. In addition, biological waste is fermented and clarified in the fermenter. The number of examples could be continued at will.
Typically, fermentation processes take place in aqueous nutrient solution. To ensure complete mass transfer, agitators are installed in the fermentation vessel. They can be shaped like a propeller, an anchor or a helix. In general, the requirements for such an agitator are as follows:
As long as the fermentation substrates are low viscosity, a simple, small agitator can diffuse and mix a large mass. Sometimes the mixing process is improved by either installing a baffle or by installing the agitator outside the axis of symmetry. An intermittent, swelling, or reversing mode may also be helpful. As long as the viscosity of the fermentation substrates is similar to water, i.e. low, agitators can achieve sufficient mixing.
The situation becomes more difficult when the viscosity increases, becoming comparable to curd cheese, cream cheese or margarine. Then three challenges must be accomplished:
The fermentation process can optionally be supplemented very effectively by stimulating the process parameters:
Answer from amixon®: Yes, they are available as amixon® conical fermenters in vertical design. A convex helical mixing tool rotates slowly inside. This design can be used for almost all rheological consistencies; low viscosity, high viscosity, semi-solid plastic masses.
The 20 m³ fermenter shown here is equipped with automatic cleaning and sterilization equipment. It processes highly viscous compounds.
Gentle homogenization is carried out with a spiral mixing tool (a). Flexible scraping tools (b) are optionally installed between the spirals. In the case of the mixing function, the goods are conveyed upwards. For discharge, the mixer rotates in the opposite direction and conveys the fermented goods downward into a conically shaped dosing system (c). This allows the discharge mass flow to be dosed out with high precision (continuously).
Both tools, the spiral mixing tool and the horizontally mounted discharge system, are mounted and driven on one side only. They are hygienically designed and microbiologically cleanable. On request, the design can be done in order to discharge against a different pressure level (overpressure or vacuum). The entire system rests on load cells.
Learn more about "Load cells and weighing of mixed materials"!