Pressure-type flow rate control apparatus

US6964279B2 · kind B2 · utility

Assignees

• FUJIKIN INCORPORATED · JP
• Tadahiro Ohmi · JP
• TOKYO ELECTRON LIMITED · JP

Inventors

• Tadahiro Ohmi · Rifu, JP
• Tomio Uno · Osaka, JP
• Osamu Nakamura · Atsugi, JP
• Nobukazu Ikeda · Osaka, JP
• Ryousuke Dohi · Osaka, JP
• Kouji Nishino · Osaka, JP
• Atsushi Matsumoto · Ishikawa, JP
• Kazuhiko Sugiyama · Tokyo, JP
• Shujiro Inui · Nishinomiya, JP
• Taiji Sakai · Tokyo, JP
• Masanori Ueyama · Hirakata, JP

Key dates

• Filing date: Nov 22, 2002
• Grant date: Nov 15, 2005
• Expiry date: Mar 3, 2023

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/7761
• WIPO field: Control
• WIPO sector: Instruments

Abstract

A pressure-type flow rate control apparatus controls the flow rate of fluid passing through an orifice to a target flow rate. The flow rate of a compressible fluid under non-critical conditions (sub-sonic) passing through the orifice is calculated by:Qc=KP2m(P1−P2)n Also provided is an improved pressure-type flow rate control apparatus in which a pressure ratio P2/P1=r, obtained from an upstream pressure P1 and a downstream pressure P2 is constantly compared with a critical value r, and under critical conditions (r≦rc), the flow rate is calculated by:Qc=KP1.Under non-critical conditions (r>rc), the flow rate is calculated by Qc=KP2m(P1−P2)n.