According to the law of foam growth and decline in the […]
According to the law of foam growth and decline in the fermentation process, there are two ways to control PMI foam: one is to reduce the chance of foam formation, by adjusting the composition of the medium, such as adding less or slowly increasing the composition of the medium that is easy to foam, and changing Certain culture conditions, such as pH, temperature, aeration rate, stirring rate, or changing the fermentation process to control.
The advantage of mechanical defoaming is that it does not need to introduce foreign substances into the fermentation broth, saves raw materials, reduces the chance of contamination, and does not increase the burden of the downstream extraction process. However, the effect of PMI foam is often not as fast and reliable as the defoaming agent. It requires certain equipment and consumes a certain amount of power. Its biggest disadvantage is that it cannot fundamentally eliminate the formation of foam, so it is often used as an auxiliary method of defoaming.
Mechanical defoaming is a physical defoaming method that breaks and eliminates bubbles with the help of strong mechanical vibration or pressure changes. The defoaming device can be installed inside or outside the tank. A defoaming paddle can be installed above the stirring shaft in the tank, and the foam can be crushed by the effect of the cyclone centrifugal field. A small amount of defoaming agent can also be added to the defoaming rotor to enhance the defoaming effect. The method outside the tank is to draw the foam out of the tank, and after the foam is broken by the acceleration of the nozzle or centrifugal force, the liquid returns to the fermentation tank.