Abstract: Hydrocyclone separator apparatus includes hydrocyclone separator(s) capable of separating light impurities from a paper-making fiber slurry. The separator inner wall is cylindrical with an apertured inlet portion adjacent one end which directs feed slurry in a vortical path along the wall to an enlarged inlet to an axial flow passage adjacent the other end. This inlet has a rim spaced radially from the wall which skims an inner part from the vortex containing predominantly the light impurities into the axial passage from which it is discharged through an apertured outlet portion of the sidewall. The remainder of the slurry vortex passes the rim to be discharged through another apertured outlet portion of the sidewall.

Abstract: A flotation cell for removal of solid particles contained in a liquid has, upstream of its inlet, a mixing chamber providing a passage through which the liquid passes to the cell inlet and in which the liquid is charged with air or other gas to form bubbles therein. This chamber is provided with at least one pair of opposed, converging walls extending across the passage to form opposite faces of a liquid flow path to a restricted gap between these walls at their greatest convergence, and so arranged that substantially all the liquid flowing through the chamber is forced to pass through such a flow path. Gas injection means provides a flow of gas under super-atmospheric pressure into the liquid flowing between these walls in the vicinity of the restricted gap between them to form bubbles in the liquid distributed across the path of flow.

Abstract: A tone sender system for producing analog tone pairs for transmission of the digits comprising a telephone number. Dual codes, multi-frequency and touch calling multi-frequency, are produced to generate simulated test call originations. This tone sender system provides in a single source the capability to generate telephone call originations requiring either multi-frequency (MF) or touch calling multi-frequency (TCMF) tone pairs for the digit transmission. The tone code to be utilized is selectable.