Fluid Dynamics in a Disc Stack Centrifuge

摘要

The modern high speed centrifugal separator is a machine used to separate phases of different densities, e.g. cream from milk, water and particles from fuel oil and lube oil, to clarify beer and wine, to concentrate yeast, etc. The separator is usually designed as a steel bowl rotating at typically 200 m/s peripheral speed, see fig. 1. Inside the bowl there are about 100-200 closely spaced corotating conical discs, between which the actual process of separation takes place. The high rotational speed and centrifugal force give possibilities to separate droplets and particles down to or even below micron size. On the other hand the high speed sets up a lot of problems to solve. Some of these problems have successfully been tackled by the Fluid Dynamics Group at Alfa Laval.