Brewer's spent grain grinder and production line for producing product with high protein content

A brewer's spent grain (BSG) grinder comprising:

• a charging tank fitted with a BSG moistening device;
• a grinding unit connected to the charging tank, the grinding unit having an outlet for discharging grinded BSG, the grinding unit comprising a stator and a rotor located coaxially with a gap defined between respective working surfaces of the stator and the rotor;
• a device for mixing and moving a mixture into the gap between the stator and the rotor, the device being fixed on a central part of an upper side of the rotor, the upper side of the rotor defining an upper end surface of the rotor;
• and
• a device for discharging grinded BSG located under the rotor;
• wherein the rotor is configured to allow staged grinding of BSG to obtain coarser fraction of BSG at an upper stage of the rotor and finer fraction of BSG at a lower stage of the rotor, the rotor comprising an upper part that is fitted with blades located around a circumference of the rotor, an outer surface of each blade being part of the working surface of the rotor.