Patent ID: 6030113
Filing Date: 2000-02-29
Classification: B01F

Abstract:
Mixing apparatus for mixing black liquid formed from cellulose production with ash formed from flue gases generated during combustion of black liquor to form a mixture of ash and black liquor, the mixing apparatus comprising:a walled vessel having a side wall and a bottom wall defining an internal volume;at least one inlet in said walled vessel for supplying black liquor to said internal volume;at least one inlet in said walled vessel for supplying ash to said internal volume;at least one outlet for removing a mixture of ash and black liquor from said internal volume;a vertical shaft rotatably mounted within said internal volume;a motor constructed and arranged to rotate said vertical shaft in relation to said walled vessel;at least one propeller constructed and arranged on an upper portion of said vertical shaft such that when said vertical shaft rotates said propeller generates a first circular flow of black liquor in which said black liquor flows downward within an inner portion of said internal volume and flows upward in an outer portion of said internal volume, said propeller having a diameter less than an inner diameter of said walled vessel;a draft tube connected to said walled vessel surrounding said propeller for facilitating the flow the black liquor downward in said inner portion of said internal volume;a disk constructed and arranged on a lower portion of said vertical shaft, wherein during rotation of said vertical shaft said downward flow of black liquor contacts said disc and is directed outward and then upward in said outer portion of said internal volume; andat least one rotating baffle constructed and arranged on a bottom side of said disk such that when said vertical shaft is rotated said at least one rotating baffle rotates and thrusts black liquor and solid particles in a direction away from said shaft and towards said walled vessel and generates a second circular flow of black liquor in which said black liquor flows downward at a periphery of said internal volume and upwards in an inner portion of said internal volume, a bottom of said at least one rotating baffle being spaced from said bottom wall of said walled vessel to avoid friction between said at least one rotating baffle and said walled vessel, and said bottom wall being sloped towards a location under said at least one rotating baffle whereby solid particles flow from an outer periphery of said bottom wall towards said location under said at least one rotating baffle, wherein said at least one rotating baffle comprises a substantially flat paddle.