Transport Device for Biomass in a Fermenter for the Generation of Biogas

Abstract

A transport device for biomass in a fermenter for the generation of biogas and a large-scale fermenter equipped therewith are provided, in which transport device or fermenter a sufficient capacity for transporting the biomass through the transport passage is ensured. This is achieved by the provision of transport cushions on the base, on the side walls and/or at the top or the cover of the transport passage. By the transport cushions being periodically filled and emptied again, the biomass is moved through the transport passage by means of a peristaltic motion.

1 . A transport device for biomass ( 22 ), in particular consisting of vegetable renewable raw materials, in a fermenter ( 2 ;  40 ) for the generation of biogas, comprising:
 a transport passage ( 18 ;  62 ) having side walls ( 6 ,  7 ;  46 ,  48 ) which are opposite one another and are connected to one another via a base surface ( 4 ) and a cover ( 5 );   a plurality of transport cushions ( 24 - i ;  66 - i ;  72 - i ) which are distributed over the transport passage ( 18 ;  62 ), can be filled with fluid and are in contact with the biomass ( 22 ) to be transported; and   a fluid control device ( 26 ) for the successive filling and emptying of transport cushions ( 24 - i ;  25 ,  66 - i ,  67 - i ;  68 - i ;  72 - i ) following one another, as a result of which a wave motion can be generated, by means of which the biomass ( 22 ) is moved through the transport passage ( 18 ;  62 );   characterized in that the transport cushions ( 67 - i ;  68 - i ) are fastened to the cover ( 5 ) and/or at least one of the two side walls ( 6 ,  7 ;  46 ,  48 ;  78 ).   
     
     
         2 . The transport device as claimed in  claim 1 , characterized in that bottom transport cushions ( 24 - i ;  66 - i ;  72 - i ) are additionally fastened to the base surface ( 4 ;  44 ). 
     
     
         3 . The transport device as claimed in  claim 1 , characterized in that the bottom transport cushions ( 24 - i ;  66 - i ;  72 - i ) can be filled with liquid, in particular with water. 
     
     
         4 . The transport device as claimed in  claim 1 , characterized in that the transport cushions ( 67 - i ) at the cover ( 5 ) can be filled with a gas which does not form an explosive gas mixture together with the biogas. 
     
     
         5 . The transport device as claimed in  claim 1 , characterized in that a transport cushion cover ( 28 ) is provided above the transport cushions ( 24 - i ;  66 - i ;  72 - i ), said transport cushion cover ( 28 ) transmitting the wave motion that can be generated by the transport cushions ( 24 - i ;  66 - i ;  72 - i ) to the biomass ( 22 ). 
     
     
         6 . The transport device as claimed in  claim 1 , characterized in that, in the case of the transport cushions at the side walls ( 6 ,  7 ;  46 ,  48 ;  78 ), the transport cushions ( 68 - i ) are assigned to one another in pairs and are arranged opposite one another. 
     
     
         7 . A large-scale fermenter for the generation of biogas from biomass according to the principle of the methanization of solids, comprising:
 a gastight digester ( 42 ) having a base plate ( 4 ;  44 );   a loading region ( 10 ;  54 ) having a loading device ( 12 ;  56 ) which passes through the gastight digester ( 42 ) and is intended for the continuous feeding of fresh biomass ( 22 ) into the digester ( 42 );   an unloading region ( 14 ;  58 ) having an unloading device ( 16 ;  60 ) which passes through the gastight digester ( 42 ) and is intended for removing spent biomass ( 22 ) from the digester ( 42 );   a transport device ( 20 ;  64 ;  70 ) as claimed in one of the preceding claims for transporting the biomass ( 22 ) from the loading region ( 10 ;  54 ) to the unloading region ( 14 ,  58 ); and   a biogas removal connection.   
     
     
         8 . The large-scale fermenter as claimed in  claim 7 , characterized in that at least one thrust cushion ( 25 ) which is expandable in the transport direction of the biomass and can be filled with fluid is provided in the region of the loading device ( 12 ;  56 ). 
     
     
         9 . The large-scale fermenter as claimed in  claim 7 , characterized in that the digester ( 42 ) comprises:
 a gastight, cylindrical, in particular circular-cylindrical, outer wall ( 46 ) extending vertically from the base plate ( 44 );   a gastight, cylindrical, in particular circular-cylindrical, inner wall ( 48 ) extending vertically from the base plate ( 44 );   a gastight cover which is connected to the outer and the inner wall ( 46 ,  48 );   as a result of which the digester ( 42 ) is fixed with an annular-cylindrical shape for accommodating the biomass ( 22 ) between base plate ( 44 ), outer wall ( 46 ), inner wall ( 48 ) and cover;   a dividing wall ( 52 ) extending vertically from the base plate ( 44 ) outer wall ( 46 ) and inner wall ( 48 );   the loading device ( 56 ) passing through the outer wall ( 46 ) on one side of the dividing wall ( 52 ); and   the unloading device ( 60 ) passing through the outer wall ( 46 ) on the other side of the dividing wall ( 52 ).   
     
     
         10 . The large-scale fermenter as claimed in  claim 7 , characterized in that a central wall ( 78 ) extends vertically from the base plate ( 44 ) between inner wall ( 48 ) and outer wall ( 46 ), as a result of which an inner transport passage ring ( 74 ) is formed between inner wall ( 48 ) and central wall ( 78 ) and an outer transport passage ring ( 76 ) is formed between outer wall ( 46 ) and central wall. 
     
     
         11 . The large-scale fermenter as claimed in  claim 7 , characterized in that the at least one thrust cushion ( 25 ) is arranged at the dividing wall ( 52 ). 
     
     
         12 . The large-scale fermenter as claimed in  claim 7 , characterized by a percolate circulation device which has a percolate storage tank which is arranged inside the cylindrical inner wall ( 48 ). 
     
     
         13 . A method of operating a large-scale fermenter as claimed in  claim 7 , comprising the method steps:
 feeding fresh biomass via the loading device ( 12 );   removing half-fermented biomass via the unloading device ( 16 ;  60 ;  50 );   separating percolate from the half-fermented biomass;   feeding the half-fermented biomass again via the loading device ( 12 ;  56 ,  50 ); and   removing the completely fermented biomass via the unloading device ( 16 ;  60 ;  50 ).   
     
     
         14 . The method as claimed in  claim 13 , characterized by the method steps:
 filtering the percolate removed from the half-fermented biomass ( 22 ); and   returning the filtrate from the percolate into the large-scale fermenter.