Self-Cleaning Separators for Liquid/Solid Separation

SPX FLOW offers a wide range of self-cleaning separators for liquid/liquid/solid separation. This type of separator allows for the recovery of fine particles (0.5–500 µm), the efficient separation of a mixture into its two phases, and the contemporary clarification of both by means of a very high peripheral centrifugal field (G-force).

Theory of Operation

Separation

The product to be treated flows into the bowl through a feed pipe (1) and into the distributor (2). It then undergoes acceleration until it reaches the bowl rotating speed. The distributor (2) then conveys the product to the disk stack (3) where the separation between the light and heavy phase takes place. Light clarified phase flows to the center of the bowl and the heavy phase flows to the bowl's outer diameter. Both phases rise in the disk stack and reach the two upper chambers of the bowl where two fixed centripetal pumps (4-5) convey them under pressure to the outlet pipelines (6-7).

Solids discharge

The separated solids are collected in the peripheral part of the bowl (8) and are periodically discharged through the discharge holes (9). The discharged solids are collected into an outer annular chamber connected to a damping sludge tank where they are drained away by gravity through a pipe. The pressure produced by water in chamber (11) keeps the hydraulically operated ram (10) in a closed position. By feeding water into pipeline (13), the bowl valve (12) allows water in chamber (11) to flow away; the product pressure pushes down the hydraulic ram and the solids are immediately ejected through the discharge holes (9). By stopping the opening water feed (13) and filling the closing water line (14) into the chamber opening (11), the hydraulic ram goes back to the closed position.

Automatic control

The periodic solids discharge is carried out automatically by means of a PLC which controls the opening and closing water solenoid valves and the solenoid valves of the operating water circuit. Various automatic, independent working cycles may be selected to perform partial and/or total discharges during separation and cleaning procedures. By setting the PLC it is possible to adjust the discharge volume, the frequency and the combination between partial and total discharges. The PLC can also perform the following functions: automatic bowl closing during the starting phase; stop feeding during total discharges; rinsing of all internal surfaces before and after the discharge; manual control of partial and total discharges; bowl overflow (during CIP); product re-circulation.