| 摘要 |
PROBLEM TO BE SOLVED: To produce fine powder snow particles of liquid carbon dioxide by providing an expansion member covering an internal path communicating a conduit and an outlet connected to the conduit with each other and having a large number of fine passages for making a low temperature liquid flow to an outlet. SOLUTION: A nozzle device 10 has an expansion member or another member having a large number of fine passages and has in its interior a low temperature liquid passage and a large number of expansion passages. In the expansion passages, expansion of the low temperature liquid occurs so that the expanding low temperature liquid (carbon dioxide or the like) is converted into fine snow particles and vapor. Then, the low temperature liquid enters the fine passages of the expansion member 14 and starts expansion on account of pressure difference, which promotes cooling. If an expansion member 14 having a sufficient thickness, temperature reaches about -57 deg.C and pressure reaches about 4.2 kg/cm<2> and the liquid and vapor flowing through the fine passages are converted into snow particles in a vicinity of an outlet of the nozzle. Diameter of the fine passage restricts size of the snow particles produced. Pressure difference across the expansion member 14 and constituents become propulsion force for emitting the snow particles. |
