Alumina autoclave digester

The utility model discloses an alumina autoclave digester which comprises a feeding pipe (4), a stirring shaft (2), a heating pipe (7) and a pipe hoop (5). The stirring shaft (2) is fixed in the middle of a cylinder body (1), the heating pipe (7) is communicated with a large ring pipe (3), a cylindrical pipe (6) is sheathed outside the heating pipe (7), and the pipe hoop (5) is fixed on the cylindrical pipe (6). The heating pipe of the alumina autoclave digester adopts the anti-breaking technology, so that the breaking frequency of the heating pipe can be effectively reduced, thereby improving the production efficiency, reducing overhauling consumption and various manpower as well as materials, ensuring safe as well as stable running of a digestion machine set, and overcoming the disadvantages in the prior art.