Apparatus and process for aerobic digestion of organic sludge

Abstract

An apparatus for treating organic sludge by aerobic digestion, in which the digestion can be realized efficiently at an improved rate of digestion of the organic sludge steadily for a long period of time, while preventing clogging of the flow path for supplying oxygen-containing gas, which apparatus comprises an aerobic digestion tank 1, a circulation line 6 provided with a pump for pumping the circulated sludge, a liquid/gas ejector 7 for aspirating the oxygen-containing gas, which has been humidified, and for mixing it with the circulated sludge, a liquid/liquid ejector 8 for mixing the circulated sludge with the sludge in a later step, a downward directing pipe 9 for passing downwards therethrough the flow of gas/liquid mixture and an ozone-treating unit 31, wherein the circulated sludge is mixed with an oxygen-containing gas in the liquid/gas ejector by jetting the circulated sludge into a throat 11 and passing the resulting mixture through the liquid/liquid ejector 8 and the downward directing pipe 9 to effect dissolution of oxygen into the sludge to cause the aerobic digestion, while the gas/liquid mixed fluid composed of the spent ozone gas and the ozone-treated sludge is guided to an aspiration chamber 13 via a line 34 as the humidified oxygen-containing gas in order to prevent clogging of flow path in the aspiration chamber 13 due to drying of the sludges into solid crust.

Dependencies are inferred from the claim text.