Patent ID: 7993521

Claim:
A plant for generating biogas from organic biologically degradable material containing liquid and solid constituents, such as waste products, in particular liquid manure from agricultural facilities, comprising a biogas generating tank having an inlet for the biologically degradable material and a biogas collecting zone, said biogas collecting zone having a biogas outlet, and a flotation-type separating device including a micro-bubble generating means for separating the solid from the liquid constituents of the biologically degradable material, said flotation-type separating device comprising a chamber zone confined in the interior of the biogas generating tank, said chamber zone being effective substantially in the direction of the force of gravity and having a closed bottom and an open upper end located below the maximum level of the liquid in the biogas generating tank, wherein a gas, in particular biogas from the biogas collecting zone is adapted to be supplied to the micro-bubble generating means for forming micro-bubbles in said chamber zone, wherein the micro-bubble generating means is disposed outside the biogas generating tank, whereby clarified liquid from the chamber zone and gas for loading the clarified liquid with gas are supplied to the micro-bubble generating means, whilst an outlet of the micro-bubble generating means for the gas-loaded clarified liquid is connected to an inlet of the chamber zone, and wherein the inlet for the gas-loaded clarified liquid is provided near the bottom of the confined chamber zone.