Disperser and method for using same

A disperser, comprising:

• a cylindrical outer member extending in a predetermined direction and having a tapered inner circumferential surface as a part of an inner circumferential surface thereof;
• and
• an inner member located radially inside the outer member and having a tapered outer circumferential surface as a part of an outer circumferential surface thereof, the tapered outer circumferential surface facing the tapered inner circumferential surface of the outer member;
• wherein the disperser is configured to allow a clearance distance between the tapered inner circumferential surface and the tapered outer circumferential surface to be adjusted by moving the outer member and the inner member relative to each other in the predetermined direction;
• wherein
• a flow path is formed between the inner circumferential surface of the outer member and the outer circumferential surface of the inner member, through which fluid flows from one side to an other side in the predetermined direction,
• the flow path includes a dispersion region defined by the tapered inner circumferential surface and the tapered outer circumferential surface,
• the tapered inner circumferential surface and the tapered outer circumferential surface are formed such that an angle therebetween in a cross section in the predetermined direction changes in a middle of the dispersion region, and
• the dispersion region of the flow path includes:
• a reduction region where the clearance distance decreases from the one side to the other side, and
• a constant region extending continuously from the reduction region to the other side, where the clearance distance is constant.