PURPOSE: To eliminate danger of bacterium contamination and fault by providing a tubular rotor having long axis in carrying direction while provided with fins for carrying liquid in carry path then rotating the rotor through an armature from the outside.

CONSTITUTION: A pump 100 is constructed with separatable carry unit 102 and drive system unit 104 into a cylinder. The carry unit 102 is coupled to a heat- exchanger 14 while matching the centers and a tubular rotor 112 is held in the tubular housing 108 and a plurality of vanes 14 are secured to the inside of rotor 112. The inner diameter of drive unit 104 is slightly longer than the outer diameter of housing 108 where a plurality of armatures 128 are arranged on a circle having the center same with the central axis of cylinder then power is fed to rotate the rotor 114.