The refiner has been planned in order to accomplish manually or automatically the simultaneous operation of suction, refining and transport of shavings through a fixed pierced cylindrical surface, oscillating and rotating inter-exchangeable hammers. It is a ventilation group concerning the field of wood refuse discharge. They have been constructed using first-class materials and in the respect of the norms in force in matter. The varied number of models, allows to satisfy both the small artisan's requirements, who can produce small amount, and the great entrepreneur's ones, who can produce greater amounts of material.