Mass flow controller
AssigneeHitachi Metals, Ltd.
InventorsTomokazu Hirota, Hiroyuki Ito
Life of this patent
Estimating the term…
Abstract
A mass flow controller includes a flow meter, a mechanical pressure-regulating valve disposed adjacent to and on an upstream side of the flow meter, and a flow control valve disposed on a downstream side of the flow meter. The mechanical pressure-regulating valve is embedded in a base of the mass flow controller. The mass flow controller also includes a compulsive valve-opening mechanism configured to compulsorily open the mechanical pressure-regulating valve. Thereby, the mass flow controller can instantly recover pressure on the upstream side of the flow meter to its original pressure even in a case where the pressure changes, and can raise measurement accuracy of a flow rate measured by the flow meter.
Claims21
A mass flow controller comprising:
- a base;
- a flow meter mounted on said base;
- a mechanical pressure-regulating valve embedded in said base and disposed adjacent to and on an upstream side of said flow meter;
- and
- a flow control valve mounted on said base and disposed on a downstream side of said flow meter
- wherein;
- said mechanical pressure-regulating valve comprises;
- a pressure-regulating chamber which constitutes a part of a channel of a fluid in said mass flow controller;
- and
- a diaphragm which separates an internal region of said pressure-regulating chamber from an external region of said channel;
- and
- said mechanical pressure-regulating valve is configured to be opened by at least one part of said diaphragm being displaced to a side of said pressure-regulating chamber when pressure of said fluid in said pressure-regulating chamber is lower than a predetermined set pressure.
A mass flow controller comprising:
- a base;
- a flow meter mounted on said base;
- a flow control valve mounted on said base and disposed on a downstream side of said flow meter;
- a mechanical pressure-regulating valve embedded in said base and disposed adjacent to and on an upstream side of said flow meter, said mechanical pressure-regulating valve comprises:
- a pressure-regulating chamber which constitutes a part of a channel of a fluid in said mass flow controller;
- and
- a diaphragm which separates an internal region of said pressure-regulating chamber from an external region of said channel;
- said mechanical pressure-regulating valve is configured to be opened by at least one part of said diaphragm being displaced to a side of said pressure-regulating chamber when pressure of said fluid in said pressure-regulating chamber is lower than a predetermined set pressure;
- and
- a valve-opening mechanism configured to open said mechanical pressure-regulating valve, said valve-opening mechanism comprises a member configured to displace at least said one part of said diaphragm to said side of said pressure-regulating chamber by an external operation.
Dependencies are inferred from the claim text.