| 摘要 |
PROBLEM TO BE SOLVED: To stabilize a flow rate of a chemical liquid by absorbing temporary increase in the flow rate due to the valve closing action of an on/off valve. SOLUTION: A mixing device 10 is constituted so that 50% hydrofluoric acid (chemical liquid) fed through a chemical liquid supply path 12 and pure water fed through a pure water supply path 14 are mixed by a mixing nozzle 16. When compressed air is supplied to the on/off valve 43 through an air duct 43a by an air supply circuit 39, the compressed air is also supplies to a flow rate stabilization part 44. When compressed air supply to the air duct 43a is stopped by the air supply circuit 39, compressed air supply to the flow rate stabilization part 44 is stopped at the same time. In such a way, the on/off valve 43 and the flow rate stabilization part 44 are operated in conjunction with each other to supply and stop the compressed air. The flow rate stabilization part 44 absorbs a flow rate change due to the valve closing action of the on/off valve 43 to stabilize the supply amount of the chemical liquid supplied to the mixing nozzle 16. COPYRIGHT: (C)2004,JPO
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