NOVELTY - Full-automatic plastic tank type biogas pool comprises spherical, or an elliptical or cylindrical plastic shell (1), material feeding U-shaped pipe (20), and material discharging U-shaped pipe (30).    USE - The tanks is useful for domestic to change manure into energy helpful for protecting the environment.    ADVANTAGE - The device has low manufacturing cost and easy installation so as to realize industrialized volume production; moreover the air tightness is good, so the possibility of gas leakage is small; the biogas pool is corrosion resistant, so the service life is long; as the biogas pool can automatically discharge the waste materials, the labor intensity is relieved.    DETAILED DESCRIPTION - Full-automatic plastic tank type biogas pool comprises a spherical, or an elliptical or cylindrical plastic shell (1), where there is a material feeding U-shaped pipe (20) and a material discharging U-shaped pipe (30) under the bottom of the shell (1); one end of the material feeding U-shaped pipe (20) is connected with the lower end of a material feeding pipe (2), the upper end of the material feeding pipe (2) is connected with a manure pit, and the other end of the material feeding U-shaped pipe (20) is connected with a material feeding short pipe (21) that is at the middle of the inner space of the shell (2); one end of the material discharging U-shaped pipe (30) is connected with the bottom of the shell (1), while the other end is connected with the lower end of a spiral or linear material discharging pipe (3); the upper end of the material discharging pipe (3) is more than 10 cm higher than the top of the shell (1); and the top of the shell (1) is provided with a gas guiding hole (4) connected with the gas storage tank.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the full-automatic plastic tank type biogas pool.    Shell (1)    Material feeding pipe (2)    Material discharging pipe (3)    Gas guiding hole (4)    Coarse material feeding hole (5)    Material feeding U-shaped pipe (20)    Material feeding short pipe (21)    Material discharging U-shaped pipe (30)