(US4749480-A)      A reaction vessel for anaerobic liq. treatment comprises a reaction chamber with a gas chamber above it and an annular subchamber around the interface between the two for receiving liq. and biomass. An annular ring separates the subchamber from the reaction chamber while flowback is provided by a lamellar appts. in the subchamber.    Pref. a central supply tube communicates with both ends of the reaction chamber and the liq. is circulated through the tube. Pref. sludge is returned to the reaction chamber via a tunnel shaped sludge pocket.    ADVANTAGE -   Sepn. of gas, liq. and biomass is provided within the reaction chamber without further sepg. means. (9pp)a    (EP182955-B)      A reaction vessel for a methane reactor for anaerobic treatment of contaminated liquids, more particularly waste water, comprising a reaction chamber (8) underneath a gas chamber (10) sealed from the environment and a sedimentation chamber (19) separated from the reaction chamber (8) by means of a wall (17) disposed in the region of the liquid level (11), a baffle plate thickener (20), an overflow channel (27) and a sludge-collecting pocket (21) being disposed in the sedimentation chamber (19), the latter being directly connected to the reaction chamber, characterised in that a plurality of baffle plate thickeners (20) are provided inside the sedimentation chamber (19) and in that a collecting channel system (26,29) is disposed on the baffle plate thickeners (20) and can be connected to the overflow channel (27) for the purpose of transferring liquid in order to discharge directly from the baffle plate thickeners the clean liquid separated therein.    (EP182955-B2)      A reaction vessel for a methane reactor for anaerobic treatment of contaminated liquids, more particularly waste water, comprising a reaction chamber (8) underneath a gas chamber (10) sealed from the environment and a sedimentation chamber (19) separated from the reaction chamber (8) by means of a wall (17) disposed in the region of the liquid level (11), a baffle plate thickener (20), an overflow channel (27) and a sludge-collecting pocket (21) being disposed in the sedimentation chamber (19), the latter being directly connected to the reaction chamber, characterised in that a plurality of baffle plate thickeners (20) are provided inside the sedimentation chamber (19) and in that a collecting channel system (26,29) is disposed on the baffle plate thickeners (20) and can be connected to the overflow channel (27) for the purpose of transferring liquid in order to discharge directly from the baffle plate thickeners the clean liquid separated therein.