the apparatus described herein uses a disc wafer - type rotor featuring channels disposed around its circumference and around the interior circumference of the rotor housing specifically to induce cavitation . the channels are shaped to control the size , oscillation , composition , duration , and implosion of the cavitation bubbles . the rotor is attached to a shaft which is driven by external power means . fluid pumped into the device is subjected to the relative motion between the rotor and the device housing , and exits the device at increased temperature . the device is thermodynamically highly efficient , despite the structural and mechanical simplicity of the apparatus . such devices accordingly provide efficient , simple , inexpensive , and reliable sources of distilled potable water for residential , commercial , and industrial use , as well as the separation and evaporation of other liquids .