摘要 |
The invention provides a flotation device including a thickening tank ( 1 ) having right cylindrical sidewalls and a downwardly sloping frusto-conical floor. A drive shaft ( 2 ) is centrally rotatably mounted within the tank. Each one of a plurality of rake arms ( 3 ) is fixedly connected to the drive shaft and extends radially outwardly, substantially parallel to the tank floor. Each arm supports an array of blades ( 4 ) extending axially into the tank. An array of baffles in the form of rectilinear baffle plates ( 5 ), fixed relative to the tank, extends axially into the tank in complementary alternate radially spaced relationship with the blades ( 4 ). The baffle plates are located within the swept volume of the blades to retard fluid rotation in response to the rotation of the rake. A diametrical service bridge ( 6 ) is fixedly connected to the tank for mounting the baffle plates. |