| 摘要 |
PROBLEM TO BE SOLVED: To generate an ideal vortex flow by a vortex flow generation device 1 by suppressing a decrease in flow velocity of a drift flow and diffusion of the drift flow without considering minimization of a full-closing-time CL8 with a heavy load in terms of costs.SOLUTION: A vortex flow generation device 1 includes: a flow passage wall step 4, which is provided downstream from a rotation track of a valve body 3 with respect to a flow of suction flow, a projection side and a depression side of the step being located on a downstream side and an upstream side with respect to the flow of the suction air respectively. Consequently, a flow (a bottom flow and a side flow) except a drift flow flowing out of a full-closing-time CL8 to the downstream side of the valve body 3 strikes on a step surface 10 to be bent, and runs from a bottom periphery and a side periphery of a flow passage 6 to the center. The bottom flow joins the drift flow while sucking the side flow, so the flow of the suction air is put together with the drift flow on the downstream side of the valve body 3. Consequently, the vortex flow generation device 1 can generate an ideal vortex flow by suppressing a decrease in flow velocity of the drift flow and diffusion of the drift flow even when the full-closing-time CL8 is present. |
