Pressure-type flow controller
First Claim
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1. A pressure-type flow controller, comprising:
- a main body provided with a gas channel communicating between a gas inlet and a gas outlet and an exhaust channel branched from the gas channel and communicating between the gas channel and an exhaust outlet;
a control valve for pressure control provided to the gas channel on an upstream side of a point of branching of the exhaust channel;
an orifice provided in the gas channel on a downstream side of the point of branching of the exhaust channel, the orifice having a fixed diameter smaller than a diameter of the gas channel at an upstream side of the orifice and at a downstream side of the orifice and being configured such that a flow rate of a gas passing through the orifice is proportional to a pressure on an upstream side of the orifice when a critical expansion condition is satisfied;
a pressure sensor for detecting an internal pressure of the gas channel between the control valve for pressure control and the orifice;
a control valve for exhaust control for opening/closing the exhaust channel; and
a controller configured to control the control valve for pressure control and the control valve for exhaust control to control the flow rate of the gas flowing downstream of the orifice based on a set flow rate,wherein the controller controls the control valve for pressure control and the control valve for the exhaust control such that the gas between the control valve for pressure control and the orifice is exhausted when the set flow rate is reduced when an opening degree of the control valve for pressure control changes to a smaller opening degree.
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Abstract
A pressure-type flow controller includes a main body provided with a fluid channel between a fluid inlet and a fluid outlet and an exhaust channel between the fluid channel and an exhaust outlet; a pressure control valve fixed to the fluid inlet of the main body for opening/closing the upstream side of the fluid channel; a pressure sensor for detecting the internal pressure of the fluid channel on the downstream side of the pressure control valve; an orifice provided in the fluid channel on the downstream side of the point of branching of the exhaust channel; and an exhaust control valve for opening/closing the exhaust channel.
19 Citations
13 Claims
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1. A pressure-type flow controller, comprising:
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a main body provided with a gas channel communicating between a gas inlet and a gas outlet and an exhaust channel branched from the gas channel and communicating between the gas channel and an exhaust outlet; a control valve for pressure control provided to the gas channel on an upstream side of a point of branching of the exhaust channel; an orifice provided in the gas channel on a downstream side of the point of branching of the exhaust channel, the orifice having a fixed diameter smaller than a diameter of the gas channel at an upstream side of the orifice and at a downstream side of the orifice and being configured such that a flow rate of a gas passing through the orifice is proportional to a pressure on an upstream side of the orifice when a critical expansion condition is satisfied; a pressure sensor for detecting an internal pressure of the gas channel between the control valve for pressure control and the orifice; a control valve for exhaust control for opening/closing the exhaust channel; and a controller configured to control the control valve for pressure control and the control valve for exhaust control to control the flow rate of the gas flowing downstream of the orifice based on a set flow rate, wherein the controller controls the control valve for pressure control and the control valve for the exhaust control such that the gas between the control valve for pressure control and the orifice is exhausted when the set flow rate is reduced when an opening degree of the control valve for pressure control changes to a smaller opening degree. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification