FIELD: pulp-and-paper industry. SUBSTANCE: installation has case with walls concentrically fixed inside the case, and opposite sides 7,8 located round axial line 2 and case 1 and being distanced from it to such an extent that passage cross-section acquires shape of concentric axial gap 9. The latter is preferably 20 mm long in direction of main stream of medium flowing through it. In addition, distributive chamber 14 is available connected with annular gap and directed upward along axis of gap and enabling uniform distribution of fibrous pulp round all concentric inlet aperture 10 of annular gap. EFFECT: Improved mixing procedure. 19 cl, 7 dwg
