A gas metering device

Abstract

This utility model discloses a gas metering device, including a measuring unit and a protection unit installed on the gas supply line between the main gas supply pipe and the user side. The measuring unit is used for gas flow measurement, and the protection unit is located downstream of the measuring unit to protect it. The protection unit includes a quick-shut-off valve, an automatic venting valve, and a check valve. The quick-shut-off valve is located upstream of the check valve to cut off the gas flow in the pipeline, and the automatic venting valve is located between the quick-shut-off valve and the check valve to relieve pressure in the pipeline. The check valve is also equipped with a differential pressure detector, which is interlocked with the quick-shut-off valve and the automatic venting valve via an electrical automation system signal. This interlocks the backflow of gas in the pipeline and discharges the gas through the automatic venting valve, thereby reducing the risk of gas backflow from the user side into the main gas supply pipe, which could lead to gas pollution or explosion.

Description

Technical Field

[0001] This utility model relates to the field of industrial gas metering technology, and in particular to a gas metering device. Background Technology

[0002] Currently, many chemical companies rely on gas operators within industrial parks for their industrial gas supply. This necessitates commercial gas metering, typically requiring the installation of commercial gas metering devices on the user side. Many chemical users have high-pressure, high-risk gas sources. To prevent backflow, commercial flow meters need to be equipped with anti-backflow devices downstream. Traditional check valves have poor sealing performance and are prone to damage and failure, potentially leading to backflow of user-side gas into the main gas supply pipe, causing gas contamination and even posing a risk of explosion. Utility Model Content

[0003] The purpose of this invention is to provide a gas metering device that prevents backflow.

[0004] To achieve the above objectives, this utility model proposes a gas metering device, including a measuring unit and a protection unit installed on the gas supply line between the main gas supply pipe and the user side. The measuring unit is used for gas flow measurement, and the protection unit is located downstream of the measuring unit to protect the measuring unit. The protection unit includes a quick-shut-off valve, an automatic venting valve, and a check valve. The quick-shut-off valve is located upstream of the check valve to cut off the gas flow in the pipeline. The automatic venting valve is located between the quick-shut-off valve and the check valve to relieve pressure in the pipeline. The check valve is also equipped with a differential pressure detector. The differential pressure detector is interlocked with the quick-shut-off valve and the automatic venting valve through an electrical automation system signal to protect the detection unit when the pipeline gas pressure is abnormal.

[0005] Preferably, the measurement system includes a flow meter, with manual shut-off valves installed in the pipes upstream and downstream of the flow meter, and a pressure relief valve installed between the manual shut-off valves and the flow meter.

[0006] Preferably, bypass pipes are provided on both sides of the measuring unit.

[0007] Preferably, the manual shut-off valve is a blind valve, which is equipped with a figure-eight blind plate.

[0008] The beneficial effects of this utility model are as follows: This invention incorporates a protection unit in the downstream pipeline of the flow meter to prevent backflow of gas from the user side to the main gas supply pipe. The protection unit includes a quick-closing valve, an automatic venting valve, and a check valve, with differential pressure detectors at both ends of the check valve. When a poor seal or damage to the check valve is detected, the quick-closing valve and the automatic venting valve, interlocked with the differential pressure detector signal, open, cutting off the backflow of gas in the pipeline and discharging the gas through the automatic venting valve. This reduces the risk of gas contamination or explosion caused by backflow of gas from the user side to the main gas supply pipe. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a gas metering device in a specific embodiment of the present invention. Detailed Implementation

[0010] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art or in accordance with the product manual.

[0011] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. See Figure 1 As shown, in a preferred embodiment of this utility model, a gas metering device is proposed, including a measuring unit 3 and a protection unit 4 installed on the gas supply line between the gas supply main pipe 1 and the user side 2, for gas metering and preventing safety issues caused by gas backflow from the user side 2 to the gas supply main pipe 1. The measuring unit 3 is used for gas flow measurement, and the protection unit 4 is located downstream of the measuring unit 3 to protect the measuring unit 3.

[0012] In this embodiment, the measuring unit 3 includes a flow meter 33, which is used to calculate the gas flow rate in the pipeline. To facilitate the inspection of the flow meter 33, a set of manual shut-off valves 31 and pressure relief valves 32 are provided on both sides of the flow meter 33 (i.e., upstream and downstream of the flow meter). The pressure relief valves 32 are located between the manual shut-off valves 31 and the flow meter 33. This configuration of the measuring unit 3 facilitates online disassembly and inspection of the flow meter 33, ensuring the safety of the gas metering device and reducing maintenance costs during production. At the same time, bypass pipes 34 are added to both ends of the measuring unit 3 to protect the measuring unit 3, ensure stable gas flow, and prevent pipeline overload.

[0013] To facilitate online disassembly and inspection of the flow meter 33, a shut-off valve 35 is installed on the bypass pipeline 34. When the flow meter 33 needs to be inspected, the manual shut-off valve 31 is closed before disassembling the flow meter 33. The shut-off valve 35 in the bypass pipeline 34 is then opened, along with the pressure relief valve 32, to release the pressure in the pipeline, ensuring the safety of personnel during the disassembly and inspection of the flow meter 33. Simultaneously, the gas continues to be delivered to the user side 2 through the bypass pipeline 34, reducing the maintenance cost of the flow meter 33 during production. To further improve the disassembly and inspection efficiency of the flow meter 33, in this embodiment, the manual shut-off valve 31 is a blind flange valve with a figure-eight blind flange, allowing for disassembly and inspection of the flow meter without removing the blind flange, making disassembly and inspection more convenient.

[0014] Meanwhile, to prevent backflow of gas from the user side 2 during the gas supply process from the main gas pipe 1 to the user side 2, a protection unit 4 is provided downstream of the measuring unit 3. The protection unit 4 includes a quick-shutdown valve 41, an automatic venting valve 42, and a check valve 43. The quick-shutdown valve 41 is located upstream of the check valve 43 to cut off the gas flow in the pipeline, and the automatic venting valve 42 is located between the quick-shutdown valve 41 and the check valve 43 to relieve pressure in the pipeline. A differential pressure detector 44 is also installed on the check valve 43. The differential pressure detector 44 is interlocked with the quick-shutdown valve 41 and the automatic venting valve 42 via an electrical automation system signal. When the system detects that the check valve 43 is not functioning properly, it can close the quick-shutdown valve 41 and open the automatic venting valve 42. High-pressure gas backflow from user side 2 causes check valve 43 to leak or malfunction. Differential pressure detector 44 will generate a negative pressure signal, causing quick shut-off valve 41 to close and automatic venting valve 42 to open. This effectively prevents high-pressure gas from flowing back from user side 2 to gas supply main pipe 1 and causing contamination of gas supply main pipe 1, thus ensuring the safety of the gas supply system.

[0015] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A gas metering device, characterized by The application relates to a gas supply system comprising a measuring unit and a protection unit arranged on a gas supply line between a gas supply main and a user side, the measuring unit being used for gas flow measurement, and the protection unit being arranged downstream of the measuring unit to realize protection of the measuring unit, The protection unit comprises a quick cut-off valve, an automatic diffusion valve and a check valve, the quick cut-off valve being arranged upstream of the check valve to realize cut-off of pipeline gas flow, and the automatic diffusion valve being arranged between the quick cut-off valve and the check valve to realize pipeline pressure relief, A differential pressure detector is further arranged on the check valve, and the differential pressure detector is signal interlocked with the quick cut-off valve and the automatic diffusion valve through an electrical automation system to realize protection of the detecting unit when pipeline gas pressure is abnormal.

2. The gas metering device of claim 1, wherein A flowmeter is arranged in the measuring unit, and a manual cut-off valve is arranged on the pipeline upstream and downstream of the flowmeter, and a pressure relief valve is arranged between the manual cut-off valve and the flowmeter.

3. The gas metering device of claim 2, wherein, Bypass pipelines are arranged on both sides of the measuring unit.

4. The gas metering device of claim 2, wherein The manual cut-off valve is a blind valve, and an 8-shaped blind plate is arranged on the blind valve.

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