Conical fermentation tanks have been widely adopted domestically, but during production, some issues may arise due to the tank's design and construction, pipeline arrangement, instrumentation, and auxiliary equipment quality. These issues can generally be summarized as follows:
Tank Leakage
Leakage is a common issue during conical tank production, typically occurring at the top of the tank. The tank top is equipped with a pressure relief valve and vacuum valve, along with several pipe connectors. Poor sealing, or improper valve operation during filling, fermentation, and filtering, may result in leaks. When leaks occur, tank pressure drops, leading to low beer CO₂ content. Regular inspections, cleaning of the pressure relief and vacuum valves, and timely replacement of seals are recommended solutions.
Beer Freezing
Beer freezing occurs at its freezing point and can be attributed to two main reasons: excessively low coolant temperature or improper cooling jacket design of the conical tank. This often happens in colder weather. To prevent freezing on the tank walls, coolant temperature should not be set too low. According to design standards, coolant water should remain between -4°C and -6°C, not lower than -8°C. Additionally, the coolant inlet should avoid the tank's low-temperature zones to minimize the risk of beer freezing.
Gradient Distribution
Due to the significant height of the conical tanks (up to several meters), poor convection can create temperature and density gradients in the liquid. CO₂ levels may be lower at the top and higher at the bottom, leading to stratification. This makes it challenging to control beer quality within the tank. The following methods can help mitigate this issue:
(1) Install a CO₂ washing device at the tank bottom to promote even mixing of the fermentation liquid.
(2) Set up upper and lower sampling points for representative sample mixing.
(3) Properly utilize the tank's cooling jacket.
Bacterial Contamination in Conical Tanks
(1) The tank has a large surface area; improper cleaning can lead to buildup, making it susceptible to bacterial contamination.
(2) Numerous external pipes connect to the tank, so all interfaces require thorough cleaning and sterilization.
(3) Frequent entry of materials or gases into the tank during production may introduce contaminants.
In general, contamination of beer within the tank severely impacts beer quality, so thorough cleaning and sterilization are essential.
Instrument Error
Instrument errors can occur due to poor instrument quality or improper operator use, often resulting in inaccurate readings of temperature, liquid level, pressure, or cleaning efficiency. Solutions include using higher-quality instruments, periodic calibration, and regular inspections to prevent operational errors.
Poor CIP Cleaning Efficiency
Poor CIP (Clean-In-Place) cleaning efficiency can stem from two main causes: improper equipment or component selection, and unsuitable cleaning agents. Addressing these issues depends on the specific cause, with appropriate corrections applied accordingly.