Trap Filtration (Post KG and/or PVPP)

The purpose of Trap Filtration is to remove any kg/de powder and other particles and to ‘polish’ the beer. For most applications we would recommend Amazon SupaPore PPG cartridges rated at 10 micron absolute. This can be used with backwashing to increase throughput and lower the operating costs. Where Backwashing isn’t preferred Amazon SupaSpun II or SupaPleat II can be used instead to good effect.

For beverage applications and to enable Backwashing the housing should be fully flowed, fully draining and suitable for CIP (Clean In Place) and/or steaming. The Amazon 62 Series and 64 Series are ideal for these requirements, as are the Amazon 70 Series housings.

Kieselguhr (kg) powder, also called diatomaceous earth (de), is a naturally occurring substance with very good absorptive qualities and has been used as a fining agent in beer production for many years to clarify and (partially) stabilise beer, changing it from coarse (and, in filter cartridge terms, unfilterable) ‘green’ beer to bright beer. In many breweries (typically the smaller establishments) this bright beer is the end product and is racked and sold ‘as is’ but in almost all medium to large breweries this beer will be further processed to remove particles (trap and fine filtration) and to kill or remove any viable organisms (by ‘sterile filtration’ or pasteurisation).

The first of these additional stages is trap filtration, the purpose of which is to remove any kg/de powder and other particles and to ‘polish’ the beer.

Most KG powder is well above 10 micron in size but as the application lends itself so well to Backwashing (by virtue of KG being a porous cake forming substance) a 10 micron absolute rated Amazon SupaPore filter cartridge is selected to ensure that the powder forms a cake on the surface of the filter medium with minimum penetration. Some breweries prefer to use 5 micron absolute.

Backwashing will typically be used where maximum life and lowest operating costs are paramount, and where experienced and/or skilled operators are available. Detailed operating protocols are available from Amazon Filters Technical Services if required. When Backwashing is employed, water for this duty should itself be filtered, to prevent it causing premature blockage of the trap filter cartridge. This can be best achieved using Amazon SupaSpun II depth filter cartridges in an Amazon 61 Series filter housing.

If simplicity and ease-of-use is more important and revenue costs are not so critical then Backwashing may not be ideal, in which case a coarser 20 micron absolute Amazon SupaSpun II or SupaPleat II filter cartridge could be used.