Abstract: A pressure exchange device is equipped with a rotator, for which first flow paths through which a first fluid flows in and out and second flow paths through which a second fluid flows in and out are arranged around a shaft center so as to penetrate through in the direction of the rotation axis. The device includes a first lateral member with a first fluid inflow path, a second fluid outflow path, a second fluid inflow path, and a first fluid outflow path. The device also includes a second lateral member with communication sections that connect the first flow paths and the second flow paths and exchange pressure between the first fluid and the second fluid.

Abstract: Disclosed is a pressure exchange device which can be made more compact and for which the cost can be reduced, without reducing the processing flow rate.