Three-phase separator and installation for biological purification of effluent

Three-phase separator for separating off from a fluid gas and particles contained therein, comprising at least one pair of two gas collection caps extending in a horizontal longitudinal direction and each having a plate section, wherein the plate sections converge in the downwards direction and at the bottom ends of the plate sections leave at least one passage, elongated in the longitudinal direction, for the fluid and particles, which passage connects a reactor chamber below the plate sections to a settling chamber above the plate sections and wherein a discharge opening for fluid, opening into the settling chamber, is provided at a level higher than said at least one passage;

• wherein
• said at least one passage comprises an inlet passage for the fluid containing the particles to be separated off, as well as an outlet passage for particles which have settled in the settling chamber;
• the inlet passage and the outlet passage are in extension of one another, viewed in the longitudinal direction;
• and
• the discharge opening, viewed in the longitudinal direction and from the inlet passage, is provided level with the outlet passage or beyond the outlet passage.