Methods of generating fine bubbles

Typical methods

Pressurized dissolution
With this method bubbles are produced by releasing, all at once, gas compressed in a liquid. This is a type of high-concentration generation, but many bubbles of 50 µm or larger are produced. There is strong tendency for bubbles to coalesce and grow in size, and bubbles rise quickly. As a result, retention time in the liquid is short.
Rotational flow method
With this method, gas and liquid are rotated at high speed, and bubbles are generated through shearing force. Minute, uniform bubbles with negative internal pressure are produced, but at low concentration so production efficiency and testing efficiency are poor.
Static mixer method
Same as pressurized dissolution method
Cavitation method
Same as rotational flow method
Venturi method
Same as rotational flow method

Method of producing HACK UFB products

We continuously and stably produce uniform, high-density fine bubbles. Fine bubbles have almost no buoyancy,
and their retention time increases.
As a result, a state of high-concentration in the liquid can be maintained for a long time.

  • (A) Gas is taken in due to pump negative pressure.
  • (B) Cavitation is produced through shearing, while pressurizing inside the generation mixing header.
  • (C) Bubbles are generated with a bubbling nozzle.

With our company’s system, highly-concentrated, uniform fine bubbles are stably generated by combining the pressurized
dissolution method, rotational flow method, and cavitation method. We have obtained a patent using this method.

HACK UFB product measurement test

Measurement date: Nov. 30 to Dec. 1, 2013 (2 days)
Measurement location: Faculty of Engineering, Shizuoka University (Mase Laboratory, Hamamatsu Campus)
Measured by: Professor Mase, M1 Nishina, D4 Sakai
Measurement equipment: NANOSIGHT, Adopted in September 2015
Measurement conditions: Camera level 12 (level enabling 108 measurement)
Measurement temperature: 30ºC
Threshold (noise removal): 6
Measured liquids: Pure water, saline water (pure water + salt [concentration 0.9%, *180 g of salt per 20 L)
Measured gases: Air, hydrogen (H2), carbon dioxide (CO2), and oxygen (O2)
Measured models: MA5S, AMB3, ASG1, BA15

*As measurement equipment conditions, the measurement standards were not specified by our company. They were set based on the long experience of Professor Mase.
*The measured data was obtained under conditions set on the university side, and thus this is fair, unbiased data.

Categories for ultra-fine bubble and microbubble diameter and number density