Introducing screw for biogas plants

Abstract

A screw conveyor for introducing organic matter into a biogas digester that is under internal gas pressure. A biogas plant may be provided with such a screw conveyor, and methods for feeding organic solids to such a biogas plant may be performed. A plug section of the screw conveyor has an expansion region in which the passage cross-section between the conveying screw and the screw pipe widens in the conveying direction and a constriction region located downstream from the expansion region, in which the passage cross-section between the conveying screw and the screw pipe is reduced in the conveying direction.

1 .- 19 . (canceled) 
     
     
         20 . A screw conveyor for introducing organic matter into a biogas digester that is under internal gas pressure, said screw conveyor comprising:
 a screw pipe extending in a longitudinal direction and having an inlet opening for organic matter in the region of a first screw pipe end and an outlet opening for the organic matter in the region of a second screw pipe end,   a conveying screw extending in the longitudinal direction and arranged inside the screw pipe and which can be made to rotate by means of a screw conveyor drive,   a digester connector for connecting the outlet opening directly to the biogas digester that is under gas pressure,   a plug section for compacting the organic matter in order to reduce any passage of gas through the screw conveyor, and   a separation section disposed upstream from the plug section, comprising a plurality of openings in the screw pipe and a fluid collection apparatus outside the screw pipe.   
     
     
         21 . A screw conveyor for introducing organic matter into a biogas digester that is under internal gas pressure, said screw conveyor comprising:
 a screw pipe extending in a longitudinal direction and having an inlet opening for organic matter in the region of a first screw pipe end, an outlet opening for the organic matter in the region of a second screw pipe end, and an inner wall,   a conveying screw (i) extending in the longitudinal direction, (ii) arranged inside the screw pipe, (iii) which can be made to rotate by means of a screw conveyor drive, and (iv) spaced from the inner wall so as to form a passage cross-section,   a digester connector for connecting the outlet opening directly to the biogas digester that is under gas pressure,   a plug section for compacting the organic matter in order to reduce any passage of gas through the screw conveyor, and   a flushing fluid port for feeding a flushing fluid into the passage cross-section in the region of the second screw pipe end downstream from the plug section.   
     
     
         22 . The screw conveyor according to  claim 21 , 
       wherein the flushing port is arranged at an end face of the screw pipe and opens into a flushing line extending axially in the longitudinal direction of the screw pipe, said flushing line extending from the second end of the screw pipe to at least one radial flushing fluid port that opens into the passage cross-section. 
     
     
         23 . The screw conveyor according to  claim 21 , 
       wherein the conveying screw is embodied in the region of the second screw pipe end as a hollow shaft for conducting the flushing fluid inside the conveying screw. 
     
     
         24 . The screw conveyor according to  claim 23 , wherein the conveying screw is rotatably mounted in the region of the second screw pipe end on a support which is fixed torque-resistantly to the screw pipe and which extends axially into a hollow space in the conveying screw.