Flow meter and flow control device provided therewith

Patent metadata

Field	Value
Publication number	US-2016239026-A1
Application number	US-201415028127-A
Country	US
Kind code	A1
Filing date	Oct 21, 2014
Priority date	Oct 28, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

A flow meter includes an inlet side switching valve, an outlet side switching valve on a downstream of the inlet side valve, and a control valve on a downstream of the outlet side valve that are connected with each other by flow passages having internal volumes, a pressure sensor on an upstream side of the control valve, and a larger flow rate measuring section for calculating a flow rate based on a build-down volume of an internal volume of the passage between an outlet of the inlet side valve and an inlet of the control valve, and a smaller flow rate measuring section for calculating a flow rate based on a build-down volume of an inner capacity of the passage between an outlet of the outlet side valve and the inlet of the control valve.

First claim

1 . A flow meter, comprising an inlet side opening and closing switching valve provided on a flow passage, an outlet side opening and closing switching valve provided to a downstream side of the inlet side opening and closing switching valve, and a control valve provided to a downstream side of the outlet side opening and closing switching valve that are connected with each other by flow passages having internal volumes, and a pressure sensor provided to an upstream side of the control valve,
wherein the flow meter also comprises a larger flow rate measuring section for calculating a flow rate based on a build-down volume which is an internal volume of the flow passage between an outlet side of the inlet side opening and closing switching valve and an inlet side of the control valve, and a smaller flow rate measuring section for calculating a flow rate based on a build-down volume which is an inner capacity of the flow passage between an outlet side of the outlet side opening and closing switching valve and the inlet side of the control valve.

2 . The flow meter according to claim 1 , wherein the control valve is a control valve in a flow rate control section.

3 . The flow meter according to claim 1 , wherein the plurality of flow passages having the internal volumes which are separated by the opening and closing switching valves are provided.

4 . A flow rate control device comprising a build-down type flow rate monitoring section provided to an upstream side, and the flow rate control section provided to a downstream side of the build-down type flow rate monitoring section,
wherein the build-down type flow rate monitoring section includes an inlet side opening and closing switching valve, a build-down capacity provided to a downstream side of the inlet side opening and closing switching valve, a temperature sensor provided to a gas passage at a downstream side of the build-down capacity, an outlet side opening and closing switching valve provided to the downstream side of the build-down capacity, a pressure sensor provided to a downstream side of the outlet side opening and closing switching valve, and a monitoring flow rate computing control section to which detected values by the temperature sensor as well as the pressure sensor are inputted, and calculates a flow rate for a larger flow rate range based on an internal volume of a gas passage between an outlet side of the inlet side opening and closing switching valve and a control valve of the flow rate control section as a build-down volume and also calculates a monitoring flow rate for a smaller flow rate range based on an internal volume of a gas passage between an outlet side of the outlet side opening and closing switching valve and the control valve of the flow rate control section as the build-down volume.

5 . The flow rate control device according to claim 4 , wherein the build-down type flow rate monitoring section and the flow rate control section are connected by a signal transmission circuit for transmitting the monitoring flow rate by the build-down type flow rate monitoring section to the flow rate control section, and a set flow rate adjusting mechanism adjusting a set flow rate of the flow rate control section based on the monitoring flow rate by the build-down type flow rate monitoring section is provided.

6 . A flow rate control device comprising a build-down type flow rate monitoring section provided to an upstream side, a flow rate control section provided to a downstream side of the build-down type flow rate monitoring section, a signal transmission circuit connecting the build-down type flow rate monitoring section and the flow rate control section to transmit a monitoring flow rate by the build-down type flow rate monitoring section to the flow rate control section, and a set flow rate adjusting mechanism adjusting a set flow rate of the flow rate control section based on the monitoring flow rate of the build-down type flow rate monitoring section, wherein the build-down type flow rate monitoring section comprises an inlet side opening and closing switching valve releasing and stopping gas supply from a gas source, a build-down capacity with a predetermined internal volume connected to an outlet side of the inlet side opening and closing switching valve, an outlet side opening and closing switching valve connected to an outlet side of the build-down capacity, a pressure sensor detecting a pressure of gas flowing through a passage at a downstream side of the outlet side opening and closing switching valve, a temperature sensor detecting a temperature of the gas flowing through the passage at the downstream side of the outlet side opening and closing switching valve, and a monitoring flow rate computing control section calculating and outputting a flow rate for a larger flow rate range by using the build-down method in case of the larger flow rate by opening the inlet side opening and closing switching valve to increase a gas pressure in the build-down volume to a set pressure upper limit value then closing the inlet side opening and closing switching valve to decrease the gas pressure in the build-down capacity to a set pressure lower limit value after a predetermined time with the outlet side opening and closing switching valve kept opened and the inlet side opening and closing switching valve operated to be opened and closed where the build-down volume is an internal volume of a gas passage between the outlet side of the inlet side opening and closing switching valve and the control valve of the flow rate control section, and that also calculates and outputs a monitoring flow rate for a smaller flow rate range by using the build-down method in case of the smaller flow rate by opening the outlet side opening and closing switching valve to increase the gas pressure in the build-down capacity to a set pressure upper limit value then closing the outlet side opening and closing switching valve to decrease the gas pressure to a set pressure lower limit value after a predetermined time with the inlet side opening and closing switching valve kept opened and the outlet side opening and closing switching valve operated to be opened and closed where the build-down volume is an internal volume of a gas passage between the outlet side of the outlet side opening and closing switching valve and the control valve of the flow rate control section, and here, the monitoring flow rates for both the larger flow rate and the smaller flow rate are calculated by a following formula.

Q
=

1000
760

×
60
×

273

(

273
+
T

)

×
V
×

Δ



p

Δ



t

Assignees

• Fujikin Kk

Inventors

• Nagase Masaaki
• Ikeda Nobukazu
• Nishino Kouji
• Dohi Ryousuke
• Hidaka Atsushi
• Sugita Katsuyuki

Classifications

• G01F15/04

  of gases to be measured · CPC title

• G01F15/005

  Valves (valves in general F16K) · CPC title

• G01F15/002

  for gases · CPC title

• G01F1/6847

  where sensing or heating elements are not disturbing the fluid flow, e.g. elements mounted outside the flow duct · CPC title

• G01F1/363

  with electrical or electro-mechanical indication (G01F1/37 and G01F1/38 take precedence) · CPC title