Method and device for anaerobically fermenting organic material
AssigneeOrganic Waste Systems, naamloze vennootschap
InventorsLuc Albert Omer Medard De Baere, Piet Lodewijk Magdalena Smis
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Abstract
This invention relates to a method for anaerobically fermenting biodegradable organic material, whereby this material is mixed with a quantity of already fermented material as an inoculum for the active anaerobic fermentation and this mixture is introduced at the top into a fermentation chamber (1A) in which a fermenting mass is situated, which, while being fermented, moves from an inlet (6A) situated at the top towards an outlet (8) situated at the bottom. Before the mixture is added to the fermenting mass, it is expanded beforehand until its density approximately coincides with the density of the already present fermenting mass at the beginning of this downward movement.
Claims19
Method for anaerobically fermenting biodegradable organic material, whereby this material is mixed with a quantity of already fermented material as an inoculum for the active anaerobic fermentation and this mixture is introduced at the top into a fermentation chamber (1A) in which a fermenting mass is situated, which, while being fermented, moves from an inlet (6A) situated at the top towards an outlet (8) situated at the bottom, characterized in that the mixture, before being added to the fermenting mass and further moving downward during fermentation, is expanded beforehand until its density approximately coincides with the density of the already present fermenting mass at the beginning of this downward movement.
Method according to any of the preceding claims, characterized in that a mixture of biologically fresh material and fermented material is fermented, having a dry matter content of 10 to 45%.
Method according to any of the preceding claims, characterized in that the downward movement of the fermenting mass in the fermentation chamber (1A) can take place in a fermentation tank (1) which is free of any mixer, whereby the mixture is introduced at the upper side of the fermentation tank (1) after it has been reduced in density in an expansion vessel (6).
Method according to any of the preceding claims, characterized in that the mixture is expanded beforehand by means of one or more of the following techniques:
- a preceding biological pre-fermentation, the injection of a gas into the mixture, the beating of- the mixture, the addition of chemicals which cause the formation of gas in the mixture.
Device for anaerobically fermenting organic waste, which comprises a vertical fermentation tank (1), an outlet (8) for fermented material at the bottom of this tank (1), and an outlet (22) for biogas at the top, and a supply device (2) which comprises a mixer (4) and which gives out into the fermentation tank (1) at the top thereof, characterized in that the supply device (2) comprises at least one vertical expansion vessel (6) which is situated between the mixer (4) and the fermentation tank (1).
Device according to any of the claims 9 to 19, characterized in that the fermentation tank (1) has a flat bottom.
Dependencies are inferred from the claim text.