Description
The pre-treated cocoa beans with their expanded shells, are fed by a dosing chute to a pre-sieving unit. From here, only whole cocoa beans pass into the (low-speed) reflex breaker where they are mechanically thrown against an impact surface. The brittle shells break into coarse pieces and the nibs break apart along their natural separating lines into large fractions. The broken product is conveyed directly to the sieving and aspiration section. The separation of the shell from the nib, plus the grading of the nib into different size ranges, is achieved by means of an aspiration/sieve combination. The material retained on the top sieve deck, mainly consists of cocoa beans that are hard to break. These are returned to a roller breaker, where after these beans are fed again to the pre-sieving unit.
The main vibrating screen box is equipped with 5 sieves, easily exchangeable, staggered one above the other. The sifting is effected by means of 6 vertical sifters made of stainless steel, lateral on the screen box. Thereby the shells are drawn upwards and the nibs fall down. The 6 fractions of shells are distributed to 6 shelves of the shell separator and discharged by a rotary valve. The nibs are collected in a discharge screw.
