The seed tank, also known as the strain culture tank, is a tank for culturing (microbial) strains for fermentation, that is, a microbial expansion tank. Stainless steel seed tanks are suitable for yogurt, lactic acid bacteria beverages, brewing, pharmaceuticals, chemicals, and fungal culture. Common strains cultured in seed tanks include those for producing monosodium glutamate, citric acid, enzyme preparations, etc. The design of the seed tank should be based on the characteristics of the microorganisms to be cultured and expanded. The difference between the seed tank and the fermentation tank is that the seed tank generally has a smaller volume and is equipped with a flame inoculation port, while the fermentation tank has no inoculation port and is connected to the seed tank to directly input the strain from the seed tank for fermentation.
The head and body of the seed tank are generally connected by flanges, which is convenient for disassembly, cleaning, and maintenance. The tank body is equipped with a long strip sight glass, and the upper head is equipped with a sight glass and a spotlight to facilitate observation of the strain culture status. Stirring can break the bubbles, make the air and solution contact evenly, and dissolve oxygen in the medium. The role of the baffle is to change the direction of the liquid flow from radial flow to axial flow, promote violent liquid turnover, and increase dissolved oxygen. The defoamer is set to break the foam. Common forms of defoamers include serrated, comb-like, and orifice plate types. The aperture of the orifice plate is about 10-20 millimeters. The length of the defoamer is about 0.65 times the diameter of the tank. The seed tank uses a jacket for heat exchange, which can maintain constant temperature, heating, and cooling. The shaft seal seals the gap between the tank top or bottom and the shaft to prevent leakage and contamination by miscellaneous bacteria.
