Refining machine

Claim 1

A refining machine for fragmented beating material such as wood chippings, shavings and the like as well as for paper pulp in higher, non-pumpable concentrations, comprising: a central body; an outer part surrounding said central body, said central body and said outer part being rotatable in relation to each other about an axis of rotation, said central body and said outer part being spaced from each other so that a rotationally symmetric, annular infeed channel is formed between said central body and said outer part, said infeed channel feeding beating material over at least a portion thereof generally in the direction of said axis of rotation and having, in the feed direction of said feeding material, gradually increasing inner and outer diameters, respectively; beating means including first and second annular parts which are respectively supported on said central body and said outer part, said beating means being arranged to be passed by the beating material after said beating material is passed through said infeed channel; the improvement wherein: said infeed channel is shaped to redirect movement of said beating material from a generally axial movement to a movement essentially radially outwards in relation to the axis of rotation of said beating means; the generatrices to the two opposing limiting surfaces of said infeed channel have a uniform continuous curvature along their entire length, and further have a successively decreasing inclination out toward said beating means, said inclination being in relation to said beating means; said limiting surfaces of said infeed channel are shaped such that the total flow area of said infeed channel increases continuously in a direction out towards said beating means; the limiting surfaces of said infeed channel stagelessly pass outwardly into said beating means; means is provided to divide said infeed channel into a plurality of generally spiral-shaped flow channels, said dividing means including spiral-shaped vanes mounted on one of said limiting surfaces of said infeed channel which is arranged to rotate, said spiral-shaped vanes protruding into said infeed channel and extending substantially up to the opposite limiting surface, thereby dividing said infeed channel into said spiralshaped flow channels; and said beating means has a coarse and a fine beating zone and wherein each of said vanes is terminated with a tongue protruding into said coarse beating zone.