| 摘要 |
PROBLEM TO BE SOLVED: To satisfy the requested stoichiometric value in a range from a small flow to a large flow. SOLUTION: An ejector 30 is provided with a diffuser 31, a nozzle 32, a needle 33 and a driving unit 34. A third passage 40 of the diffuser 31 is provided with a throat part 41 and an enlarged diameter part 43, and the nozzle 32 and the needle 33 are coaxially arranged with the third passage 40. A first tapered part 51 of the needle 33 is inserted into an opening part 44 of the nozzle 32, and a second tapered part 52 is housed in the enlarged diameter part 43. A clearance between the opening part 44 and the first tapered part 51 forms a first fluid passage 53, and a clearance between the enlarged diameter part 43 and the second tapered part 52 forms a second fluid passage 54. The needle 33 is movably provided in the axial direction by the driving unit 43, and both the first and the second fluid passages 53 and 54 can be changed at the same time by moving the needle 33 in the axial direction. |
