GEA whirlpools have proven to be reliable in operation and work to the highest standards. A technical understanding of the brewing materials and process, of wort properties, fluid dynamics and the complex way they interact, are essential for the design of a Whirlpool vessel. Apart from the raw materials used in the brew and the up-stream conditions in the brewhouse, the successful function of the Whirlpool is very much dependent on the wort mass flow, the entry velocity into the vessel, the vessel geometry and the resulting flow conditions as well as the arrangement of the wort outlets. It is only when all these criteria are in the correct balance that the formation of a compact trub cone in the centre of the Whirlpool can be guaranteed.