Spinning Cone Column
The spinning cone column (SCC) is an efficient and extremely versatile steam stripping column. One of its main applications is the removal of alcohol from full-strength beer in order to produce non-alcoholic (NAB) and low-alcoholic beer (LAB).
The SCC provides breweries with a multi-purpose installation capable of producing both NAB and LAB even from unfiltered beer, without compromising CIP procedures. Compared with other products sometimes used to remove alcohol from beer, the SCC provides breweries with numerous important benefits, such as:
- beer quality remains intact due to reduced thermal impact on the product
- opportunities for aroma recovery
- reduction of alcohol levels to as low as 0.05% alcohol by volume (abv) in one single pass without damaging the product
- significantly lower energy consumption due to high mass transfer efficiency
- no need to de-gas the feed beer prior to removing the alcohol
- space-saving design due to the compactness of the skid-mounted installation.
The SCC is designed as an easy-to-install module and is built to comply with relevant engineering and regulatory standards, including hazardous area requirements (complies with ATEX class II 3G). The column features a self-regulating function for operating pressure and strip rate. The hygienic design includes the use of stainless steel for all surfaces that the beer comes into contact with, while the elastomers in contact with the product are of food-grade quality. A sanitary steam generator provides the steam needed for the process. The installation can be cleaned effectively using CIP procedures, with spray devices for the column. A special CIP tank for this purpose is installed on the skid. Aroma recovery The SCC has an option for aroma recovery, where the flavours are stripped first and then collected in an alcoholic condensate that can be re-dosed into the final beer. This can be achieved with a two-column set-up.
How it works
The SCC consists of a vertical column that features rotating and stationary metal cones placed alternately (Figure 1), with counter-current flows of gas and liquid to bring the two phases into contact. The system works under vacuum at temperatures of 40–45°C (104–113°F). A thin, turbulent film of liquid flows down the column over the upper surface of each cone. The flow is induced by the alternate effects of centrifugal and gravitational forces. Gas (vapour) flows up the column in the spaces between the cones (Figure 2). Radial fins on the lower surfaces of the rotating cone ensure maximum turbulence in this phase. This improves efficiency and has a pumping effect on the vapour phase, which results in a reduced pressure drop across the column. This is important when removing alcohol from beer because it results in consistently lower temperatures in the system, and consequently reduces any thermal impact, which affects the quality of the product – in this case beer.
Characteristics of the liquid flow
- Thin, turbulent films
- Extended flow path
- Low liquid hold-up volume
- Evenly distributed, rapid passage
- Characteristics of the vapour flow
- Highly turbulent (due to the action of the fins)
- Low pressure drop, resulting in operation at lowertemperature
In general, this means highly efficient mass transfer, while the beer is only subjected to very limited thermal impact. This
ensures effective removal of the alcohol content using only a minimum of energy.