| 摘要 |
PROBLEM TO BE SOLVED: To uniformly mix >=2 kinds of fluids in a fixed ratio. SOLUTION: A mixing apparatus 10 is constituted so as to mix 50% hydrofluoric acid (liquid chemical) supplied through a liquid chemical supply route 12 and purified water supplied through a purified water supply route 14 in a mixing nozzle 16. In the mixing apparatus 10, after a flow control valve 50 for supplying a fluid (purified water) to be mixed in high mixing ratio is opened, stop valves 30 and 44 for supplying a fluid to be mixed in low mixing ratio are opened in the start up of the supply of the fluids and after the stop valves 30 and 44 for supplying the fluid (liquid chemical) to be mixed in the low mixing ratio are stopped, the flow control valve 50 for supplying the fluid to be mixed in the high mixing ratio is closed in the stoppage of the supply of the fluid. As a result the liquid having a prescribed concentration is stably supplied without lowering the concentration of the liquid prepared by mixing purified water with the liquid chemical which are discharged from a mixing nozzle 16 to equal to or below a normal value.
|
