Process for making conical spare parts for refiners for the production of paper

A process for making a stator for a refiners used for preparing paper pulps, where the pulp enters at one end and exits at another end of said refiner, passing through a rotor equipped with bars and a stator bearing fixed counter-bars, whereby both said rotor and said stator are constituted by a series of metal sectors placed adjacent to each other, said process comprising the following series of steps:

• a) mechanical machining of unmachined metal pieces to obtain said sectors, whereby each sector is machined to obtain, on a surface thereof, one or more recesses suitable for co-operating with one or more flanges;
• b) routing or mechanical machining of said sectors by a machine tool to obtain on another surface thereof a set of said bars;
• c) assembling said sectors by placing them adjacent to each other on said flanges to obtain said stator having a conical shape;
• d) fixing the adjacent sectors to each other and to said flanges in order to obtain said stator in which said bars are directly obtained on said another surface of each of said sectors, without any sector supporting plate;
• e) mechanical turning and grinding of said stator to obtain a finished conical shape;
• and
• f) balancing said stator.

A process for making a rotor for a refiner used for preparing paper pulps, where the pulp enters at one end and exits at another end of said refiner, passing through a said rotor equipped with bars and a stator bearing fixed counter-bars, whereby both the rotor and the stator are constituted by a series of metal sectors placed adjacent to each other, said process consisting of the following steps:

• a) mechanical machining of unmachined metal pieces to obtain said sectors, whereby each sector is machined to obtain, on a surface thereof, one or more recesses suitable for co-operating with one or more flanges,
• b) routing or mechanical machining by milling of said sectors by a machine tool to obtain on a another surface thereof a set of said bars;
• c) assembling said sectors by placing them adjacent to each other on said flanges to obtain a said rotor having a conical shape;
• d) fixing the adjacent sectors to each other and to said flanges in order to obtain a said rotor in which said bars are directly obtained on said another surface of each of said sectors, without any sector supporting plate;
• e) mechanical turning and grinding of said rotor to obtain a finished conical shape;
• and
• f) balancing said rotor.