Method and device for high-efficiency hydrodynamic separation of heavy materials

Abstract

Important variables which influence the efficiency of a hydrodynamic separation of dense materials using a hydrocyclone are the dynamic viscosity at the inflow of the hydrocyclone and the number of passes through the hydrocyclone. According to the invention, the method and the device allow a control of the viscosity in the hydrocyclone as well as the number of passes through the hydrocyclone when separating dense materials from a slurry in conjunction with an anaerobic fermentation of the constituents of the slurry which can be fermented. By fermenting the constituents of the slurry which can be fermented, the content of a fermentation reactor has a lower viscosity than the slurry being fed. The viscosity in the inflow of the hydrocyclone is set by means of a controlled return flow from a fermentation reactor, and the number of passes is set by a controlled return flow from the outflow of the hydrocyclone. The slurry is pumped into a return flow from the fermentation reactor. The viscosity in the inflow of the hydrocyclone is controlled by the throughput of the return pump on the basis of the content of solids of the slurry. The number of passes through the hydrocyclone is controlled via the ratio of the feed of the hydrocyclone to the feed of the fermentation reactor from which dense materials are removed. Because the process of diluting the slurry with the content of the fermentation reactor does not have an influence on the hydraulic dwell time in the fermentation reactor, the fermentation reactor can be designed for a smaller accumulation of slurry.