Parallel divided flow-type fluid supply apparatus, and fluid-switchable pressure-type flow control method and fluid-switchable pressure-type flow control system for the same fluid supply apparatus

• US 6,422,264 B2
• Filed: 12/13/2000
• Issued: 07/23/2002
• Est. Priority Date: 04/16/1999
• Status: Expired due to Term

• Current Assignee: Fujikin Incorporated, Tadahiro Ohmi, Tokyo Electron Limited
• Original Assignee: Fujikin Incorporated, Tadahiro Ohmi, Tokyo Electron Limited
• Inventors: Sugiyama, Kazuhiko, Kagatsume, Satoshi, Ohmi, Tadahiro, Morimoto, Akihiro, Yamaji, Michio, Matsumoto, Atsushi, Koizumi, Hiroshi, Hirose, Jun, Hirose, Takashi, Ikeda, Nobukazu, Nishino, Kouji, Dohi, Ryousuke, Uno, Tomio, Uenoyama, Toyomi, Nagaoka, Hideki, Ideta, Eiji, Minami, Yukio, Fukazawa, Kazuo, Yonehana, Katsunori
• Primary Examiner(s): Buiz, Michael Powell
• Assistant Examiner(s): Krishnamurthy, Ramesh
• Application Number:
  US09/734,640
• Publication Number:
  US 20010004903A1
• Time in Patent Office: 587 Days
• Field of Search: 137/14, 137/486, 137/487.5, 137/624.11, 118/703, 118/715, 438/935, 700/282, 700/306
• US Class Current: 137/487.5
• CPC Class Codes: G05D 7/0658 the plurality of throttling means being arranged for the control of a single flow from a plurality of converging flows G05D7/0652 takes precedence; ratio control G05D11/13
• CPC Class Codes: G05D 7/0664 the plurality of throttling means being arranged for the control of a plurality of diverging flows from a single flow G05D7/0652 takes precedence; ratio control G05D11/13
• CPC Class Codes: Y10S 438/935 Gas flow control
• CPC Class Codes: Y10T 137/0396 Involving pressure control
• CPC Class Codes: Y10T 137/7759 Responsive to change in rate of fluid flow
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve
• CPC Class Codes: Y10T 137/86389 Programmer or timer
• CPC Class Codes: Y10T 137/87877 Single inlet with multiple distinctly valved outlets
• CPC Class Codes: Y10T 137/87917 Flow path with serial valves and/or closures

Abstract

A fluid supply apparatus with a plurality of flow lines branching out from one pressure regulator with the flow lines arranged in parallel and constructed so that opening or closing one flow passage will have no transient effect on the steady flow of the other flow passages. Each flow passage is provided with a time delay-type mass flow controller MFC so that when one closed fluid passage is opened, the mass flow controller on that flow passage reaches a set flow rate Qs in a specific delay time Δt from the starting point.

The invention includes a method and an apparatus in which a plurality of gas types can be controlled in flow rate with high precision by one pressure-type flow control system.

Claims

1. A parallel divided flow fluid supply apparatus, comprising:

a pressure regulator having an upstream side and a downstream side;

a plurality of parallel flow passages disposed downstream of said pressure regulator, wherein a single flow of fluid from said pressure regulator is branched into said parallel flow passages;

a plurality of flow control valves disposed in said flow passages; and

a plurality of time delay mass flow controllers for controlling flow rate, one controller installed on each flow passage between two of said flow control valves disposed upstream and downstream of said controller respectively, wherein said one controller on a flow passage is so set that when said one controller is actuated to open the passage for a steady flow state at a preset flow rate, a delay time is allowed for the flow rate to rise from the starting point to the preset flow rate value, wherein each time delay mass flow controller comprises;

a sensor section disposed immediately downstream of the upstream flow control valve of said controller for detecting an instantaneous flow rate of fluid coming through the upstream flow control valve;

wherein said sensor section comprises an upstream sensor for generating heat and a downstream sensor for detecting the heat generated by said upstream sensor;

a means for calculating an instantaneous flow rate using signals from said sensor section, said means for calculating being connected to said sensor section;

an amplifier for amplifying the signals from said means for calculating, said amplifier being connected to said means for calculating;

a valve open/close detector connected to the downstream flow control valve of said controller for detecting an open/close state of both downstream and upstream flow control valves of said controller;

a delay time unit connected to said valve detector for setting a delay time period during which the instantaneous flow rate gradually increases;

a flow rate setter connected to said delay time unit for setting a set flow rate, wherein the set flow rate will be reached during the delay time period set by said delay time unit;

a comparison circuit disposed between said amplifier and said delay time unit for comparing the instantaneous flow rate from said amplifier with the set flow rate set by said flow rate setter and outputting difference signals;

a means disposed next to said comparison circuit for receiving the outputting difference signals and displaying the outputting difference signals; and

a valve unit disposed downstream of said sensor section and connected to said comparison circuit for increasing the flow rate gradually up to the set flow rate according to signals from said comparison circuit.

2. A parallel divided flow fluid supply apparatus as defined in claim 1, wherein said delay time is adjustable.

3. A parallel divided flow fluid supply apparatus as defined in claim 1, wherein said delay time is 0.5 to 7.0 seconds.

4. A parallel divided flow fluid supply apparatus as defined in claim 1, wherein when said valve open/close detector detects a turn of the downstream and upstream flow control valves from the closed position to the open position, said delay time unit begins to work after a short stop time.

5. A parallel divided flow fluid supply apparatus as defined in claim 4, wherein said short stop time is zero to 5 seconds.