Method and apparatus for producing microfine frozen particles

In an apparatus for producing fine frozen particles and including a vessel for containing a refrigerant liquid, the improvment comprising:

• a means for making ripples at the surface of a refrigerant liquid contained in said vessel;
• an atomizer for atomizing a mixture of a liquid and a gas toward said refrigerant liquid,
• means for collecting frozen particles out of a refrigerant liquid in said vessel for disposal outside said vessel;
• said means for collecting frozen particles comprising:
• a frozen particles-collecting pipe whose lower end opens as an inlet in a refrigerant liquid in said vessel and whose upper end opens as an outlet above the liquid level in the refrigerant vessel and outside said vessel, said frozen particles-collecting pipe having at its lower end a bubble-generating device for causing the refrigerant liquid to form with bubbles a rising current inside the frozen particles-collecting pipe;
• means positioned close to said outlet for separating the frozen particles from the refrigerant liquid, both being discharged from said outlet;
• and,
• a return pipe for recirculation the refrigerant liquid thus separated from the discharged frozen particles into said refrigerant vessel,
• the positioning of theses collecting devices being so arranged that, when the bubble-generating device is working the liquid head pressure between the position of the bubble-generating device and the liquid level in said refrigerant vessel is large relative to the liquid head pressure between the position of the bubble-generating device and the level of the outlet of the frozen particles-collecting pipe.