| 摘要 |
1523996 Treating waste liquids NITTETU CHEMICAL ENG Ltd 15 Dec 1976 [15 Dec 1975] 52443/76 Heading C1B [Also in Division F4] In a method of treating concentrated waste liquid containing organic and inorganic components, e.g. waste liquid from a fermentation process, by feeding it into an incinerator 1 wherein it is combusted with auxiliary fuel and air, the combustion gases from the incinerator are fed via a downcomer pipe into an evaporator 2 to directly contact fresh waste liquid supplied from a storage tank 9, the resulting slurry or ash dispersed in the concentrated liquid being withdrawn from the evaporator 2 and fed into a decanter 5 for effecting solid-liquid separation into a concentrated liquid phase and a sedimentation phase, with part of the concentrated liquid phase from the decanter 5 being fed into the upper part of the incinerator for spray incineration. The remainder of the separated concentrated liquid phase is returned to the evaporator 2. The moisture laden combustion gases leaving the top of the evaporator 2 are fed into a mist separator 3 and then into a venturi scrubber 4 before being discharged to atmosphere through a stack 12. The sedimentation phase is fed into a drying chamber 6 wherein it is dried and stirred to form dry granulated particles which can be used as a fertilizer. The fertilizer composition comprises inorganic salts such as potassium salts plus organic components of the concentrated original waste liquid which serve as a binder. A generator 8 supplies hot gas to the drier 6. Waste gas leaving the drier 6 is passed through a cyclone 7 and therafter fed into the Venturi scrubber 4. Drying is effected at temperatures not higher than 250‹ C., preferably 100-200‹ C. Incineration is carried out at a temperature between 700‹ C. and 1500‹ C. preferably 750-900‹ C. |
