Abstract: A stirring device of a plug-flow fermentation device includes a shaft rotatable about an axis of rotation which defines an axial direction. The stirring device further includes a boundary stirring element that defines the axial extent of a stirring volume covered by the stirring device. A nearest neighbor of the boundary stirring element in the axial direction has an axial maximum width which is smaller than an axial maximum width of the boundary stirring element and which is larger than an axial maximum width of a next-nearest neighbor of the boundary stirring element.

Abstract: A biogas plant is provided comprising a fermentation container for receiving fermentation material to be fermented. The fermentation container comprises a lower wall part and an upper wall part where the upper wall part is positioned above the lower wall part. Further, the biogas plant comprises a support and a hinge wherein the hinge hingedly connects the fermentation container to the support and wherein the hinge defines a pivot axis about which the upper wall part and the lower wall part are pivotable.

Abstract: In accordance with embodiments of the herein disclosed subject matter it is described a stirring device (100) comprising a shaft rotatable about an axis of rotation; a stirring element (106) attached to the shaft, the stirring element (106) having a recess (108); the recess (108) having a surface portion (114) and an edge (116), the edge (116) defining an opening which provides access to the surface portion (114); the recess (108) being spaced from the shaft, wherein a rotation of the shaft defines a moving direction (120) of the recess (108) in which the edge (116) forms a leading edge of the recess (108); the surface portion (114) defining a depth (122) of the recess (108) with regard to the edge (116); and wherein in a direction (124) radially inwardly the depth (122) of the recess (108) is decreasing.

Abstract: In accordance with embodiments of the herein disclosed subject matter it is described a stirring device (200) for a biogas fermenter wherein the stirring device (200) is configured for stirring a fermentation material and comprises a shaft (102) rotatable about an axis of rotation and a mounting structure (106) attached to the shaft (102). The mounting structure (106) has a first connection surface (112) and the second connection surface (114) and a stirring element (116) is attached to the first connection surface (112) and the second connection surface (114). The first connection surface (112) and the second connection surface (112) are located at opposite sides of the shaft (102) with the shaft being located between the first connection surface (112) and the second connection surface (114). The stirring element (116) may be configured to be spaced from the shaft (102) when the stirring element (116) is attached to the first connection surface (112) and the second connection surface (114).