Patent ID: 8101132

Claim:
A mixing device for mixing stock oil with a particulate catalyst, comprising: a moving bed forming unit that forms a cylindrical moving bed by continuously dropping the catalyst from the top to the bottom while distributing the catalyst in an annular form; a reaction tube that surrounds the moving bed formed by the moving bed forming unit; an internal stock oil supply part that has an internal stock oil injection nozzle for supplying the stock oil over the entire area in a circumferential direction of an inner surface of the moving bed formed by the moving bed forming unit; and an external stock oil supply part having an external stock oil injection nozzle for supplying the stock oil over the entire area in a circumferential direction of an outer surface of the moving bed formed by the moving bed forming device, wherein when a mass flow per unit area of the moving bed is Q [kg/m 2 s], the difference between an outer diameter and an inner diameter of the moving bed W [m], an inner diameter of the reaction tube D [m], a linear velocity of a horizontal component of the stock oil at a jet orifice of the internal stock oil injection nozzle u 1 [m/s], the stock oil being supplied from the internal stock oil supply part, and a linear velocity of a horizontal component of the stock oil at a jet orifice of the external stock oil injection nozzle u 2 [m/s], the stock oil being supplied from the external stock oil supply part, 8.0 ≧Q ×( W/D )/( u 1 +u 2), Q=300 to 2000 [kg/m 2 s], W/D=0.2 to 0.5, u 1 =5 to 300 [m/s], and u 2 =5 to 300 [m/s] are satisfied.