# US 12,111,671 B2 · Mass flow controller and flow control method therefor

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- Number: US 12,111,671 B2
- Document ID: US12111671B2
- Status: Granted
- Kind: B2
- Application number: 18/562,942
- Filed: 2022-05-27
- Published: 2024-07-11
- Granted: 2024-10-08
- Earliest claimed: 2021-05-28
- Assignees: Beijing Sevenstar Flow Co., Ltd.
- Applicants: Beijing Sevenstar Flow Co., Ltd.
- Inventors: Bowen Deng; Changhua Mu; Yitao Zou
- Web page: https://patentgrep.com/patent/US12111671B2

## CPC

- G05D 7/0635: {by action on throttling means (G05D7/0688, G05D7/0694 take precedence)}
- C23C 16/4412: {Details relating to the exhausts, e.g. pumps, filters, scrubbers, particle traps}
- C23C 16/45525: {Atomic layer deposition [ALD]}
- C23C 16/45546: {specially adapted for a substrate stack in the ALD reactor}
- C23C 16/52: Controlling or regulating the coating process {(C23C16/45557, C23C16/279 take precedence)}
- F16K 1/12: with streamlined valve member around which the fluid flows when the valve is opened
- F16K 1/54: Arrangements for modifying the way in which the rate of flow varies during the actuation of the valve
- G05D 7/06: characterised by the use of electric means {(G05D7/005 takes precedence)}
- G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)}

## Abstract

A mass flow controller includes control module, fluid passage, flow regulating valve, flow sensor disposed between inlet and flow regulating valve, and pressure sensor disposed at outlet. The control module is configured to enter pressure feedback regulation mode when variation amount of target flow value exceeds preset threshold, and enter flow feedback regulation mode after fluid flow value detected by flow sensor meets first stabilization condition. The control module is configured to, in pressure feedback regulation mode, perform calculation according to fluid pressure value and target flow value to obtain opening regulation amount, and regulate opening degree of flow regulating valve according to opening regulation amount. The control module is also configured to, in flow feedback regulation mode, perform calculation according to fluid flow value and target flow value to obtain opening regulation amount, and regulate opening degree of flow regulating valve according to opening regulation amount.

## Claims

### Claim 1

A mass flow controller, with a fluid passage provided in the mass flow controller, and a valve connected between an inlet of the fluid passage and an outlet of the fluid passage, wherein the mass flow controller further comprises a control module, a flow sensor, and a pressure sensor, wherein
the flow sensor is disposed between the inlet and the valve, and is configured to detect a fluid flow of the fluid passage;
the pressure sensor is disposed at the outlet, and is configured to detect a fluid pressure of the fluid passage;
the control module is configured to enter a pressure feedback regulation mode in response to a variation amount of a target flow exceeding a preset threshold, and enter a flow feedback regulation mode after the fluid flow detected by the flow sensor meets a first stabilization condition, wherein
the control module is configured to, in the pressure feedback regulation mode, regulate an opening degree of the valve according to a difference between the fluid pressure detected by the pressure sensor and a target pressure corresponding to the target flow; and
the control module is configured to, in the flow feedback regulation mode, regulate the opening degree of the valve according to a difference between the fluid flow detected by the flow sensor and the target flow;
wherein the variation amount of the target flow refers to a difference between a target flow currently received by the control module and a previous target flow.

### Claim 2 (depends on 1)

The mass flow controller of claim 1, wherein the control module is further configured to, before entering the pressure feedback regulation mode, acquire a valve opening degree value corresponding to the target flow, and regulate the opening degree of the valve according to the valve opening degree value until the fluid pressure detected by the pressure sensor meets a second stabilization condition.

### Claim 3 (depends on 2)

The mass flow controller of claim 2, wherein a plurality of flow set points and valve opening degree values corresponding to the plurality of flow set points are stored in the control module; and
the control module is configured to perform a calculation by interpolation according to two of the plurality of flow set points closest to the target flow and valve opening degree values corresponding to the two of the plurality of flow set points to obtain the valve opening degree value corresponding to the target flow.

### Claim 4 (depends on 3)

The mass flow controller of claim 3, wherein the valve is a solenoid valve, and each of the plurality of flow set points corresponding to an up opening degree value and a down opening degree value; and
the control module is configured to, in a case where the target flow is increased, perform the calculation by interpolation according to the two of the plurality of flow set points closest to the target flow and up opening degree values corresponding to the two of the plurality of flow set points to obtain the valve opening degree value corresponding to the target flow, and to, in a case where the target flow is decreased, perform the calculation by interpolation according to the two of the plurality of flow set points closest to the target flow and down opening degree values corresponding to the two of the plurality of flow set points to obtain the valve opening degree value corresponding to the target flow.

### Claim 5 (depends on 1)

The mass flow controller of claim 1, wherein the flow sensor is a thermal flow sensor.

### Claim 6 (depends on 2)

The mass flow controller of claim 2, wherein the first stabilization condition is: a difference between a maximum value and a minimum value among fluid flows detected by the flow sensor during a first preset time is not greater than a first preset difference; and
the second stabilization condition is: a difference between a maximum value and a minimum value among fluid pressures detected by the pressure sensor during a second preset time is not greater than a second preset difference.

### Claim 7 (depends on 1)

A flow control method of a mass flow controller, wherein the flow control method is applied to the mass flow controller of claim 1, and comprises:
in response to a variation amount of a target flow exceeding a preset threshold, regulating an opening degree of a valve according to a difference between a fluid pressure detected by the pressure sensor and a target pressure corresponding to the target flow; and
after a fluid flow detected by the flow sensor meets a first stabilization condition, regulating the opening degree of the valve according to a difference between the fluid flow detected by the flow sensor and the target flow.

### Claim 8 (depends on 7)

The flow control method of claim 7, further comprising:
in response to the variation amount of the target flow value not exceeding the preset threshold, regulating the opening degree of the valve according to the difference between the fluid flow detected by the flow sensor and the target flow.

### Claim 9 (depends on 7)

The flow control method of claim 7, wherein, before regulating the opening degree of the valve according to the difference between the fluid pressure detected by the pressure sensor and the target pressure corresponding to the target flow, the flow control method further comprises:
acquiring a valve opening degree value corresponding to the target flow, and regulating the opening degree of the valve according to the valve opening degree value; and
after the fluid pressure detected by the pressure sensor meets a second stabilization condition, performing the step of regulating the opening degree of the valve according to the difference between the fluid pressure detected by the pressure sensor and the target pressure corresponding to the target flow.

### Claim 10 (depends on 9)

The flow control method of claim 9, wherein acquiring the valve opening degree value corresponding to the target flow comprises:
determining, according to a plurality of flow set points and valve opening degree information corresponding to the plurality of flow set points that are set in advance, two of the plurality of flow set points closest to the target flow and valve opening degree values corresponding to the two of the plurality of flow set points, and performing a calculation by interpolation to obtain the valve opening degree value corresponding to the target flow.

### Claim 11 (depends on 10)

The flow control method of claim 10, wherein each of the plurality of flow set points corresponds to an up opening degree value and a down opening degree value; and
acquiring the valve opening degree value corresponding to the target flow comprises:
in a case where the target flow is increased, determining, according to the plurality of flow set points and up opening degree values corresponding to the plurality of flow set points that are set in advance, the two of the plurality of flow set points closest to the target flow and up opening degree values corresponding to the two of the plurality of flow set points, and performing the calculation by interpolation to obtain the valve opening degree value corresponding to the target flow; and
in a case where the target flow is decreased, determining, according to the plurality of flow set points and down opening degree values corresponding to the plurality of flow set points that are set in advance, the two of the plurality of flow set points closest to the target flow and down opening degree values corresponding to the two of the plurality of flow set points, and performing the calculation by interpolation to obtain the valve opening degree value corresponding to the target flow value.