The Basic Research for Pulverization of Rice Using Underwater Shock Wave by Electric Discharge


  • M Ide
  • M Shibuta
  • N Wada
  • S Tanaka
  • H Hamashima
  • S Itoh



In recent years, the food self-support rate of Japan is 40%, and this value is the lowest level in major developed countries. This reason includes decreasing of diverting rice consumption in Japan and increasing abandonment of cultivation. Therefore, these problems are solved by using rice powder instead of expensive flour, and we manage to increase the food selfsupport rate.

Previously, the rice powder is manufactured by two methods. One is dry type, and the other is wet type. The former is the method getting rice powder by running dried rice to rotating metal, and has a problem which that starch is damaged by heat when processing was performed. The latter is performed same method against wet rice, and has a problem which a large quantity of water is used. As a method to solve these problems, an underwater shock wave is used. Shock wave is the pressure wave which is over speed of sound by discharging high energy in short time. Propagating shock wave in water is underwater shock wave. The characters of underwater shock wave are long duration of shock wave because water density is uniform, water is low price and easy to get and not heat processing.

Thinking of industrialization, the electric discharge is used as the generating source of underwater shock wave in the experiment. As the results, the efficiency of obtaining enough grain size, 100ìm, of rice powder was too bad only using the simple processing using underwater shock wave. Therefore, in Okinawa National College of Technology collaborating with us, obtaining rice powder with higher efficiency by using converged underwater shock wave is the goal of this research.

In this research, the underwater shock wave with equal energy of the experimental device of underwater shock wave is measured by the optical observation. In addition, the appearance converging underwater shock wave is simulated by numerical analysis, and the pressure appreciation rate between the first wave and converged underwater shock wave is calculated by using the pressure history of 2nd focal point.


Characteristics of bread prepared from wheat flours blended with various kinds of newly developed rice flours. J. Food Sci., 2009.

About promotion of the rice powder using, The Ministry of Agriculture, Forestry and Fisheries of Japan, 2011



How to Cite

Ide, M., Shibuta, M., Wada, N., Tanaka, S., Hamashima, H. and Itoh, S. (2011) “The Basic Research for Pulverization of Rice Using Underwater Shock Wave by Electric Discharge”, The International Journal of Multiphysics, 5(2), pp. 115-130. doi: 10.1260/1750-9548.5.2.115.




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