1: Composition of liquid strain fermentation tank
The fermentation tank is composed of kettle body, inlet and outlet, safety valve, pressure gauge, temperature probe, inoculation port, seed outlet, air inlet, exhaust port, feed port, sampling port, sewage outlet, etc.
2: Mixing method of liquid strain fermentation tank
At present, edible fungus fermentation tank basically adopts air lift stirring, relying on sterile compressed air as the lifting force of liquid, so that the internal fermentation liquid can be mixed and mass transfer and heat transfer process can be achieved by flipping up and down.
Its characteristics: simple structure, no shaft seal, not easy to pollute, high oxygen mass transfer efficiency, low energy consumption, easy installation and maintenance. When the bottom air intake is adopted, the agitator breaks the air bubbles, disperses the large bubbles into smaller bubbles, increases the gas-liquid contact interface, and improves the oxygen mass transfer rate.
3: Air equipment
Air compressor equipment is an important part of liquid fermentation, including screw machine, gas storage tank, cold dryer, dry adsorption machine, etc.
Its sterilization process is as follows:
The inhaled air is first filtered before compression and then enters the air compressor. The air output by the compressor (pressure higher than 0.3 MPa, temperature 80~120℃) is first cooled to 20~25℃, oil and water are removed, and finally sterilized by the filter to obtain sterile air that meets the process requirements. Throughout the process, the equipment is designed to improve air quality and remove oil and water.
4；Air equipment composition:
The first part is the screw machine and its ancillary equipment, which is used to improve air quality, remove impurities and microorganisms, and reduce wear and load. Screw machines are divided into oil-filled and oil-free types. The main difference lies in the lubrication method. The oil-filled screw machine is lubricated by oil, which is low in cost, but has high requirements for subsequent filter elements. The oil-free screw machine is lubricated by water, which is high in cost, but the air does not contain oil, has low load on the sterilization filter element, and has good stability in the fermentation tank. The second part is from the gas tank to the dry adsorption machine equipment to remove oil and water from the compressed air, ensure that the air humidity is ≤ 60%, and meet the air intake requirements of the sterilization filter.
5: Precautions for use and procurement
(1) Check the pressure gauge and safety valve regularly, and replace or repair them in time if they fail. Before use, disassemble and clean the exhaust device, and check the valves, pressure gauges and other components to ensure they are normal. If any abnormality or accident occurs during operation, stop the operation immediately and report it for processing.
(2) Anti-pollution requirements for fermentation tanks: The tank body has no leakage, material accumulation, or dead corners. The fermentation tank is made of 304 stainless steel, polished inside and outside, with high contact surface finish, which improves cleanliness and reduces the risk of contamination.
