Abstract: A cylindrical heat exchanger composed of a cylindrical inner housing formed with smooth internal and external surfaces and a cylindrical outer housing shell formed at opposite ends thereof with a pair of cylindrical portions and at an intermediate portion thereof with a plurality of axially equally spaced annular portions partly reduced in diameter, wherein the outer housing shell is coupled with the inner housing such that the cylindrical portions and annular portions of the outer housing shell are engaged with the external surface of the inner housing to form a plurality of axially spaced annular flow passages communicated with each other through communication passages formed at each one side of the annular portions, and wherein a flow passage composed of the annular flow passages and communication passages is communicated at its one end with an inlet formed in one end portion of the outer housing shell and at its other end with an outlet formed in the other end portion of the outer housing shell.

Abstract: An auger type ice making machine having an auger composed of an auger body integrally formed thereon with a helical blade and a support shaft united with a lower end of the auger body, the auger being mounted for rotary movement with an evaporator housing and connected at its support shaft to an output shaft of a drive mechanism for rotation therewith, wherein the support shaft of said auger is composed of a cylindrical joint member formed in a predetermined axial length and having a joint portion formed to be coupled with the output shaft for rotation therewith and a columnar support member coupled with an internal bore of the joint member, and wherein the columnar support member is formed with a conical recess tapered upward from its lower end and positioned concentrically with the internal bore of the joint member.