  Nanobubble-related technologies have been confirmed to be useful in various
fields such as climate change and the environment as well as water-based
industries such as water purification, crops, horticulture, medical care, bio,
and sterilization. However, a method of mass production in real time enough to
apply nano-bubbles to the industry has not yet been developed. We explored the
mechanism of nano-bubble water generation by friction between water and walls
and developed a tube device applying the shape of the flow path to maximize the
friction in the fluid passing through the flow path. It also describes the case
of real-time and low-power mass production of nanobubbles and its technical
utility. We found that the friction of nanotubes alone can easily and quickly
improve the production of nanobubbles with small particle size in real time; by
increasing the shearing pressure while increasing the effective friction
constant value, the particle size of nanobubbles can be smaller while
increasing the particle concentration.
