MICROBUBBLE GENERATOR DEVICE

PROBLEM TO BE SOLVED: To improve the durability to a high pressure fluid of a spiral flow passage in a microbubble generator device that uses a high-speed swirling gas/liquid two-phase method.SOLUTION: Provided is a microbubble generator device in which pressurized fluid is supplied to a liquid passage 17 of a liquid supply unit 12. Liquid is guided and sprayed, to a reduced diameter section 21, downward from the liquid passage 17 in the circumferential direction along a helical blade, the helical blade being provided to the inner side of the outer side-cylindrical section of a helical passage-forming body 19. Sprayed liquid is guided along the conical surface of the reduced diameter section 21 in a helical shape toward a gas/liquid mixing section 22 and accelerated, and a high-speed swirling flow that flows towards the nozzle tip is generated in the gas/liquid mixing section 22. Negative pressure generated in the center of the gas/liquid mixing section 22 by the high-speed swirling flow causes gas to be sucked into the gas/liquid mixing section 22 from a gas inlet pipe 24, and a gas/liquid two-phase swirling fluid is generated. Gas/liquid two-phase swirling fluid is sprayed/released from the tip opening of the gas/liquid mixing section 22 that has a reduced diameter to outside of the nozzle, thereby shearing the gas/liquid two-phase fluid and generating microbubbles.