- Technical contribution
Pall’s CBS Technology for Continuous Beer Stabilization
Pall CBS System - New Trends in Colloidal Beer Stabilization
Today consumers expect a beer with a long shelf life free of changes in clarity and appearance. Colloidal stability, in addition to microbial stability, is the main influencing quality criteria for a sufficient shelf life of packaged beer.
PVPP stabilization with the classic regeneration process allows repeated use of the PVPP powder combined with candle or horizontal leaf filters. The main challenge with this process is the ongoing movement of the PVPP particles through dosing, stirring and pumping. This causes erosion of the relatively soft PVPP particles enabling the PVPP to pass through the filter candles or screens. The typical loss rate from a regenerable PVPP system is between 0.5 and 2 %. This means in practice, that after 50 to 200 filtrations, the PVPP has been exchanged completely.
To overcome these disadvantages Pall has developed with the CBS system a new technology which capitalize on the positive attributes and characteristics of the classical PVPP regenerable process but eliminate the disadvantages.
The CBS Concept
For the stabilizing material, well known standard PVPP from two main suppliers is the basis. For better control of the stabilization effect and for minimizing the PVPP loss to a level below measuring point the particle size range of the standard materials is narrowed down to a defined spectrum.
The defined PVPP is then immobilized in stainless steel cassettes, where it remains without any movement during its entire service life. This can be several years of operation without opening of the cassettes.
Between 20 and 30 cassettes are installed in a housing, representing one stabilization column. Three to six columns build a process unit, which is connected to a valve block and a CIP unit.
The CBS Process
During processing, the columns are operated in an alternating sequence, with different columns switching between processing beer, regeneration and standby. Typically, one column is in standby or regeneration, while the other two are in operation providing a constant output. Inside the system, the flow through each column is controlled with a flow meter and a regulation valve and varies during the stabilization process to utilize the PVPP adsorber capacity at maximum efficiency. Level of stabilization is adjusted by various parameters depending on the type of beer, raw material quality etc.
The CBS System Design
The size of the housings is tailored to the CBS stainless steel cassette design resulting in low hold up volumes combined with fast brand changes and minimized beer and extract losses.
The regeneration process applies the same process steps as with classical PVPP systems by using standard caustic and acids. Due to the compact design, the required quantities are reduced significantly which supports lower operation cost.
The overall footprint of the system is small compared to other technologies and allows flexible positioning.
Oxygen pick up from the start is minimal while foam, color, haze, bitterness and taste remain unaffected. Stabilization effect is highly constant during the entire process.
The main economic advantage is the negligible loss rate of PVPP which is typically at < 0.3% over a total of 1000 regeneration cycles. This corresponds to a runtime of 2 to 3 years before the PVPP in the cassette requires a change out.
Cassettes are used multiple times, reloading takes place at the brewery. Water and cleaner consumption are low compared to other technologies.
The CBS technology operates in various breweries stabilizing all kind of beers. The cassettes have a performance warranty of 1000 regeneration cycles which is often exceeded. The ability to run the CBS continuously makes it the ideal solution in combination with continuous crossflow clarification systems.