Fluidized bed grading and drying device applicable to high-moisture and large-grain-size low-rank coal

The invention discloses a fluidized bed grading and drying device applicable to high-moisture and large-grain-size low-rank coal. The fluidized bed grading and drying device comprises a fluidized bed grading and preheating chamber, a coarse-grain fluidized bed drying chamber, a medium-grain fluidized bed drying chamber and a fine powder fluidized bed drying chamber, wherein the coarse-grain fluidized bed drying chamber is arranged at the lower part of the fluidized bed grading and preheating chamber; the medium-grain fluidized bed drying chamber and the fine-powder fluidized bed drying chamber are respectively arranged in front of and at the back of the fluidized bed grading and preheating chamber; coal grains are graded and preheated by the grading and preheating chamber; the graded coal grains overflow from different overflow pipes and are respectively fed into the coarse-grain fluidized bed drying chamber and the medium-grain drying chamber; fine powder brought out by exhausting is fed to the fine powder drying chamber through a cyclone separator and is dried; the dried fine powder is independently collected by micro powder brought out by exhausting. According to the fluidized bed grading and drying device disclosed by the invention, a grading and drying mode, namely grading first and then drying is adopted, so that coal grains are dried sufficiently and uniformly, and the energy-saving effect is good.