Overview: Beer fermentation equipment is mainly divided into fermentation tanks and yeast expansion tanks, each of which has raw material preparation, cooking, sterilization and cooling. Ventilation adjustment and sterilization, and agitators can also be set.
Fermentation tank: undertake the production task of the product. It must be able to provide the conditions required for microbial life activities and metabolism, and be easy to operate and control to ensure the realization of process conditions and obtain high yields.
Yeast expansion tank: the purpose is to ensure the amount of bacteria necessary for fermentation tank culture.
Definition: A fermenter is a container that provides a favorable environment for a specific biochemical process. For some processes, the fermenter is a closed container with a precision control system; for other simple processes, the fermenter is an open container, sometimes even as simple as only one opening, which can also be commonly known as Open fermenter.
1. Should have a tight structure
2. Good liquid mixing characteristics
3. Good mass transfer phase heat transfer rate
4. Equipped with supporting and reliable detection, safety components and control instruments
It is generally considered that the fermenter below 500L is a laboratory fermenter; the fermenter with a capacity of 500-5000L is a pilot test fermenter; and the fermenter above 5000L is a production scale fermenter.
Cylindrical conical bottom fermenter: round simplified conical bottom vertical fermenter (referred to as conical tank), which has been widely used in the production of beer fermented above or below. The conical tank can be used for pre-fermentation or post-fermentation alone, and the pre-fermentation and post-fermentation can also be combined in this tank (one-pot method).
The advantage of this equipment is that it can shorten the fermentation time and has production flexibility, so it can be suitable for the production of various types of beer.
Such equipment is generally placed outdoors. The sterilized fresh wort and yeast enter the tank from the bottom; when the fermentation is at its peak, all cooling jackets are used to maintain a suitable fermentation temperature.
The refrigerant mostly uses ethylene glycol or alcohol solution, and ammonia (direct evaporation) can also be used as the refrigerant; CO2 gas is discharged from the top of the tank. Manholes are installed on the tank body and the tank cover, and the tank top is equipped with a pressure gauge, a safety valve and a glass sight glass.
A purified CO2 gas tube is installed at the bottom of the tank. The tank body is equipped with a sampling tube and a thermometer connection. The outside of the equipment is wrapped with a good insulation layer to reduce the loss of cooling capacity.
(1) The energy consumption is low, the pipe diameter adopted is small, and the production cost can be reduced.
(2) For the yeast deposited at the bottom of the cone, the valve at the bottom of the cone can be opened to discharge the yeast out of the tank, and some of the yeast will be reserved for the next use.
Factors affecting the cost of fermentation equipment:
Fermentation equipment size, type, operating pressure and required cooling workload. The form of the container mainly refers to the surface area required for its unit volume, expressed in ㎡/100L, which is the main factor affecting the cost.
Tank pressure requirements:
Consider CO2 recovery. It is necessary to keep the CO2 in the tank at a certain pressure, so the large tank becomes a pressure tank, and it is necessary to set up a safety valve.
The working pressure of the tank varies according to its different fermentation processes. If it is used for both pre-fermentation and wine storage, it should be based on the CO2 content during storage, and the required pressure resistance is slightly higher than that of a tank used only for pre-fermentation.
According to the British design rules Bs5500 (1976): if the working pressure of the large tank is x pounds per square inch, the tank pressure used in the design is x (1 ten 10%).
When the pressure reaches the design pressure of the tank, the safety valve should start to open. The maximum working pressure of the safety valve is the design pressure plus 10%.
The vacuum in the tank is mainly caused by the series of fermentation tanks being transferred or internally cleaned under closed conditions. The speed of feeding large fermenters is very fast, resulting in a certain negative pressure. A part of CO2 gas remains in the tank, and CO2 may be removed during cleaning, so it may also cause a vacuum.
Large vacuum fermenters should be equipped with devices to prevent vacuum. The function of the vacuum safety valve is to allow air to enter the tank to establish a balance of pressure inside and outside the tank.
The amount of CO2 removal in the tank can be calculated according to the alkali content of the incoming cleaning solution, and further calculate the amount of air that needs to enter the tank.
Convection and heat exchange in the tank:
The convection of the fermentation broth in the fermenter mainly depends on the effect of CO2. A gradient of CO2 content is formed throughout the fermentation broth in the conical tank. The fermented liquid with smaller specific gravity has lifting power to float up.
Moreover, the carbon dioxide bubbles rising during fermentation have a drag force on the surrounding liquid. Due to the gas stirring effect caused by the combination of drag force and lifting force, the contents of the tank are circulated and the mixed-phase heat exchange of the fermentation liquid is promoted. Variations in beer temperature during cooling operations also cause convective circulation of the contents of the tank.