NOVELTY - Horizontal three-layer methane generator tank comprises a barrel body, an end cover and a pedestal, where the barrel body includes methane storing cabin, a vacuum thermal preserving layer and a methane generating cabin. The methane generating cabin is a cylindrical shell, where the top portion of the shell has a methane pipe, which passes into the methane storing cabin by the vacuum thermal preserving layer. The vacuum thermal preserving layer includes an inner container (9), a keel, a thermal preserving layer, a shell (8) and a sealing head (11).    USE - Used as a horizontal three-layered methane generator tank.    ADVANTAGE - The methane generator tank: not only increases compression strength and expansion-resisting capability, but also solves the problems of heat convection, heat exchange and heat radiation; increases the thermal preserving performance of the methane generating cabin for quickly and successfully generating methane; and is normally operated in cold regions.    DETAILED DESCRIPTION - Horizontal three-layer methane generator tank comprises a barrel body, an end cover and a pedestal, where the barrel body includes methane storing cabin, a vacuum thermal preserving layer and a methane generating cabin. The methane generating cabin is a cylindrical shell, where the top portion of the shell has a methane pipe, which passes into the methane storing cabin by the vacuum thermal preserving layer. The vacuum thermal preserving layer includes an inner container (9), a keel, a thermal preserving layer, a shell (8) and a sealing head (11). The shell of the methane generating cabin is used as the inner container. The keel is fixedly welded on the outer surface of the inner container, and the thermal preserving layer prepared by the asbestos material is packed on the outer surface of the inner container by a metal screen. The shell of the vacuum thermal preserving layer is fixedly welded on the keel. Two ends of the barrel body mounted between the inner container and the shell of the vacuum thermal preserving layer are sealed by the sealing heads. The methane storing cabin comprises an inner container, a shell, a keel, a thermal preserving layer and a sealing head. The shell of the vacuum thermal preserving layer is used as the inner container of the methane storing cabin, and the shell of the barrel body is used as the shell of the methane storing cabin. The keel, the thermal preserving layer and the sealing head are mounted between the inner container and the shell, and the structure and the installing mode are same to that of the vacuum thermal preserving layer.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the horizontal three-layered methane generator tank.    Shell (8)    Inner container (9)    Sealing head (11)