At present, most breweries use internal calandria in brew kettles, and the wort calandria is installed vertically in the kettle. An umbrella-shaped overflow cover is installed above the calandria to distribute the rising wort to all sides while avoiding the formation of foam and ensuring that the wort is evenly heated. However, when configuring equipment, some breweries will choose to use an “external calandria brew kettle”, which adds a shell and tube heat exchanger to the outside of the brew kettle. In this article, Tiantai will introduce the working principle and characteristics of an “external calandria brew kettle” in detail.
The wort boiling equipment commonly used in breweries includes internal calandria, external calandria brew kettle, low-pressure brew kettle, and continuous or flowing wort brew kettle. The “external calandria brew kettle” introduced in this article belongs to in vitro boiling. External calandria usually refers to tube-type or plate-type calandria made of stainless steel plates for circulation heating. It is installed outside the brew kettle and can be used with 2~3 brew kettles simultaneously.
When the brew kettle is in operation, the wort passes through the calandria directly from bottom to top or through several turns and reversals of parallel tubes at a speed of about 2.5m/s. To speed up the circulation of the wort, the wort will be circulated by pumps, about 8~10 times per hour. After the external calandria heats the wort, it enters the brew kettle in a tangential direction or directly into the conduit with an umbrella cover in the center of the brew kettle. The heat transfer effect of this boiling method is relatively good. The boiling temperature of the wort is adjusted by controlling the inlet valve. Generally, the temperature of the external boiling wort is 107℃~110℃.
Working principle of external calandria brew kettle
The wort passes through the calandria directly from bottom to top or through several turns and reversals of parallel tubes at a speed of about 2.5m/s. To speed up the circulation of wort, a wort delivery pump needs to be installed between the brew kettle wort outlet and the calandria. After the wort is heated by the calandria, it enters the brew kettle from the tangential direction or directly delivers the wort to the wort duct with an umbrella cover through the center line.
Advantages and disadvantages of external calandria brew kettle
Advantages:
- The boiling time can be shortened by 20% to 30%, saving energy;
- The utilization rate of bitter substances is improved, and the precipitation of solidifiable nitrogen is more thorough;
- The number of wort cycles can be adjusted according to the process requirements;
- The required saturated steam pressure is low, only 0.3MPa;
- The boiling intensity and boiling temperature can be easily adjusted;
- With the help of the pressure relief effect, more volatile substances that are not conducive to taste can be evaporated;
- A good boiling effect can reduce the pH value of the wort and make the color lighter.
Disadvantages:
- High power consumption;
- External calandria is prone to cause a large amount of radiation heat loss;
- The wort has a high flow rate in the external calandria, which is easy to form a large shear force and affects the quality of beer flavor;
- The equipment investment cost is high.
When purchasing beer equipment, the brew kettle’s capacity should not be less than 9hL/100kg feed amount. If the design capacity is too small, the ideal boiling effect cannot be achieved, and wort overflow can easily occur. Breweries can choose boiling equipment suitable for themselves according to their actual needs and production conditions. Shandong Tiantai Beer Equipment specializes in providing various types of beer production equipment.
