The uniformly-heated
bell jar type reduction furnace comprises a
bell jar body, the bottom end of the
bell jar body is inserted into the top end of an
insertion cavity, the
insertion cavity is installed at the top end of a base, a
heat transfer box is installed at the top end of the base, a heat conduction layer is installed at the top end of the
heat transfer box, and a limiting cavity is installed at the top end of the heat conduction layer. A limiting cavity is formed in the top end of the base, a
raw material containing cavity is formed in the top end of the limiting cavity, a first rotating cavity is formed in the bottom end of the
raw material containing cavity, a first rotating block is rotationally connected into the first rotating cavity, and a spiral conveying rod is installed at the top end of the first rotating block. And the
polycrystalline silicon raw materials are uniformly heated, so that the heated and reduced
polycrystalline silicon raw materials are uniformly heated, the subsequent screening step is reduced, the problems of non-uniform growth of
silicon rods and non-uniform grain size distribution are avoided, and the practicability and convenience of the device are improved.