Patent ID: 7661651

Claim:
A dilution liquid flow controlling apparatus used in connection with the headbox of a paper-making machine or a cardboard-manufacturing machine comprising: a valve which controls dilution flow, the valve including: a valve housing, a stem part, a flow channel between an inlet and an outlet of the valve, and a sleeve member fitted inside the housing, the sleeve member serving as a mixing sleeve and having an inner surface, wherein the sleeve member includes a transverse top end, and wherein the inner surface of the sleeve member includes: an upper truncated conical portion that extends directly from the top end of the sleeve member and tapers inwardly and downwardly from the transverse top end in a direction toward a lower end of the sleeve member, a transverse lip portion extending inwardly in a radial direction from a lower end of the upper truncated conical portion, the transverse lip portion being adapted to deflect the fibre containing medium flow toward the stem part, wherein the stem part includes: a single conical-shaped tip part, a diameter of which decreases in a direction of the outlet, a ring-shaped transverse surface extending radially outwardly at an upper end of the single conical-shaped tip part, and a single truncated conical part extending upwardly from an outer circumferential edge of the ring-shaped transverse surface, wherein the stem part is movable in the sleeve member between at least two positions, a first position in which a flow path between the inlet and the outlet is open, and a second position in which the single truncated conical part of the stem part is fitted against a part of the inner surface of the sleeve member that is immediately below the transverse lip portion, in which case the flow path is closed and wherein the single conical-shaped tip part has an upper end adjoining the ring-shaped transverse surface and a lower end which is a lower-most part of the stem part.