FLOCCULATION APPARATUS AND METHOD

PROBLEM TO BE SOLVED: To enhance treatment capacity per one mixing pipe and the flocculation capacity of a flock forming tank by supplying a mixing soln. and an injection soln. certain in the concn. of an electrolite to the mixed soln. flowing through a mixing pipe from the discharge orifice of an injection pipe to bring them to a laminar contact state to perform flocculation in an increase pipe or the flock forming tank. SOLUTION: An injection soln. 16 is supplied to an injection pipe 19 and the discharge orifice of the injection pipe 19 (injection soln. 16) is turned toward the downstream direction of the polluted soln. flowing through a mixing chamber 17. The injection soln. 16 discharged from the discharge orifice of the injection pipe and the polluted soln. flowing through the mixing pipe 17 are brought to a laminar flow contact state to form a flock-containing sol. 28 which is discharge from the discharge orifice of the mixing pipe 8. The mixing pipe 17 is arranged in the increase pipe and the flock-containing soln. 28 discharge from the discharge orifice 8 of the mixing pipe and the increase pipe polluted soln. 34 flowing in the increase pipe 31 from an increase annular pipe part 37 are allowed to flow together and collides with other to form flock. Further, in the fluidized bed above the collision mixing part 20 of a flock forming bed 7, violent collision of medium and small flocks is repeated to form large flock.