Abstract: A method for producing tert-butyl alcohol, including (i) a step of feeding a raw material liquid including isobutylene and water, to a reactor having a cation exchange resin, and (ii) a step of producing a reaction product including tert-butyl alcohol, by hydration reaction of isobutylene in the reactor, in which, in step (ii), the average superficial linear velocity of the raw material liquid, as calculated in the following expression (I), is 5 m/hour or more, Average linear velocity of raw material liquid (m/hour)=Volume flow rate of raw material liquid (m3/hour)/Cross-sectional area of reactor (m2)??(I), and the volume of an aqueous phase (Vw) in a fluid (fluid A) to the total volume of the fluid A in the reactor is 4 to 12% by volume.

Abstract: A drive rotor has a coupled portion to which a coupling portion extending from a rotary shaft is loosely fitted. A driven rotor can be engaged with the drive rotor with respect to a rotating direction of the drive rotor. A restricting member is fixed to the rotary shaft so as to be integrally rotatable. In the case that the drive rotor is inclined with respect to the rotary shaft, the restricting member can be brought into contact with the drive rotor. Accordingly, it is possible to suppress an excessive looseness in a coupling mechanism.

Abstract: A drive rotor has a coupled portion to which a coupling portion extending from a rotary shaft is loosely fitted. A driven rotor can be engaged with the drive rotor with respect to a rotating direction of the drive rotor. A restricting member is fixed to the rotary shaft so as to be integrally rotatable. In the case that the drive rotor is inclined with respect to the rotary shaft, the restricting member can be brought into contact with the drive rotor. Accordingly, it is possible to suppress an excessive looseness in a coupling mechanism.