Apparatus for disperser plate and method to refine paper

A disperser assembly comprising:

• opposing arrays of fusion plate segments, wherein each fusion plate segment in the opposing arrays of fusion plate segments comprises a front surface having rows of alternating fusion bars and grooves, wherein each fusion bar has a planar upper surface and each row of alternating fusion bars and grooves is separated by annular dams located at substantially fixed radial locations on the front surface of each opposing fusion plate segment, wherein a number of alternating fusion bars and grooves increases as the rows of alternating fusion bars and grooves extends radially outward along the front surface, wherein the opposing arrays of fusion plate segments are arranged such that the annular dams on one fusion plate segment align with a row of fusion bars and grooves on an opposing fusion plate segment;
• and wherein the grooves form a serpentine passage extending radially between the opposing arrays of fusion plate segments.