Method and apparatus for the two-stage grinding of fresh stock

A method for grinding fresh stock comprising the steps of:

• comminuting the fresh stock to ground stock in a roller gap between two rotatably mounted rollers of a first roller press;
• dividing the ground stock at a variably adjustable ratio by means of an adjustable separator of a separator installation into a first part-flow of ground stock and into a second part-flow of ground stock;
• and
• comminuting the ground stock of the first part-flow to re-ground stock in a second roller press;
• further comprising:
• dividing the ground stock that exits from the roller gap of the first roller press by means of the separator of the separator installation
• into a central flow of ground stock which is formed from ground stock that exits from a central, in relation to a longitudinal direction of the roller gap, roller gap region;
• and
• into two peripheral flows of ground stock which, in each case, are formed from ground stock that, in each case, exits from one of two peripheral roller gap regions that are mutually spaced apart by the central roller gap region;
• wherein a combination of the two peripheral flows of ground stock forms the first part-flow of ground stock, and the central flow of ground stock forms the second part-flow of ground stock;
• and
• guiding the second part-flow of ground stock from the separator installation in at least one bypass line so as to bypass the second roller press.

A device for grinding fresh stock, said device comprising:

• a first roller press for comminuting a stock bed of the fresh stock to ground stock, wherein the first roller press has a longitudinally extending roller gap between two rotatably mounted rollers;
• a separator installation configured to divide the ground stock at a variably adjustable ratio by means of adjustable separator elements into a first part-flow of ground stock and into a second part-flow of ground stock;
• and
• a second roller press that, in the material flow direction, is downstream of the separator installation, configured to comminute the ground stock of the first part-flow to re-ground stock;
• the separator installation being disposed directly below the roller gap of the first roller press, wherein
• the separator elements are mutually disposed so as to be approximately symmetrical to a center of the roller gap that is defined in relation to a longitudinal extent of the roller gap, in order to divide the ground stock that exits from the roller gap into
• a central flow of ground stock formed from ground stock that exits from a central, in relation to the longitudinal extent of the roller gap, roller gap region;
• and into
• two peripheral flows of ground stock which, in each case, are formed from ground stock that, in each case, exits from one of the two peripheral roller gap regions that are mutually spaced apart by the central roller gap region;
• and wherein
• the first part-flow of ground stock is defined as a combination of the two peripheral flows of ground stock and the second part-flow of ground stock is defined as the central flow of ground stock;
• and wherein
• at least one bypass line is connected to the separator installation and is configured to guide the second part-flow of ground stock to bypass the second roller press.