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

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.