A backflush valve applied to a flue gas sampling probe

Abstract

The present application relates to a kind of backflush valve applied to flue gas sampling probe, including valve body;Valve core is arranged in valve body;Upper valve cover and lower valve cover are respectively arranged in the upper and lower ends of valve body;Flue gas inlet connector is arranged in lower valve cover, and sequentially communicated with lower valve cover, valve core, the flue gas inlet connector is configured to connect sampling probe;Flue gas outlet connector is arranged in upper valve cover, and sequentially communicated with upper valve cover, valve core, the flue gas outlet connector is configured to connect measuring cell;Backflush connector is arranged in lower valve cover, and sequentially communicated with lower valve cover, valve core, the backflush connector is configured to connect compressed gas;The valve core includes empty pipe and float ball, empty pipe is the taper empty pipe of upper end pipe diameter greater than lower end pipe diameter, float ball is configured to float up and down in empty pipe;The channel diameter of upper valve cover and valve core communication is less than the diameter of float ball.The overall structure is simple, small and exquisite, and valve core uses mechanical mechanism to operate the on-off of each road in valve, which is more safe and reliable.

Description

Technical Field

[0001] This invention relates to a valve, specifically a backflush valve applied to a flue gas sampling probe, belonging to the technical field of environmental monitoring sampling equipment. Background Technology

[0002] A continuous emission monitoring system (CEMS) can continuously and in real-time track and test the concentration (mg / m3) and emission rate (kg / h, t / d, t / a) of particulate matter and gaseous pollutants in flue gas emitted from stationary pollution sources (such as boilers, industrial furnaces, incinerators, etc.). It generally consists of four basic parts: a dust detection subsystem, a gaseous pollutant monitoring subsystem, a flue gas parameter monitoring subsystem, and a system control and data acquisition and processing subsystem.

[0003] Most CEMS online flue gas monitoring products employ high-temperature extraction sampling and light scattering measurement methods. However, in CEMS flue gas measurement, the emitted smoke often contains a large amount of particulate matter, and optical testing equipment must eliminate interference from these particles. Therefore, CEMS sampling probes are generally equipped with filters. After prolonged use, the filters become clogged with particulate matter from the flue gas, requiring backflushing with compressed air to clean them. During backflushing to clean the filter, the compressed gas must be kept separate from the measurement cell. This allows a large airflow to directly blow onto the filter, enhancing the filtration effect, and also protects the precision optical equipment inside the measurement cell from the impact of the compressed gas.

[0004] Due to the requirements of optical and flue gas characteristics, the area near the measuring cell is generally a high-temperature region (ranging from 100 to 300°C). Traditional methods mostly use high-temperature solenoid valves or high-temperature pneumatic valves to switch the gas path, separating the measuring cell from the backflushing compressed gas during backflushing, or, if necessary, separating the measuring cell from the probe. However, existing high-temperature solenoid valves or high-temperature pneumatic valves are limited in model, making installation complex when introduced into online monitoring systems. They also require the design of a controller and, to ensure accuracy, a heat insulation structure, resulting in a complex and bulky overall design. Summary of the Invention

[0005] To address the shortcomings of existing technologies, a backflush valve for flue gas sampling probes is provided. It is not only simple in structure and compact in design, but also effectively separates compressed gas from the measuring cell during backflush, eliminating the need for other redundant structures.

[0006] To achieve the above objectives, this application provides a backflush valve for a flue gas sampling probe, comprising: a valve body; a valve core disposed within the valve body; an upper valve cover and a lower valve cover respectively disposed at the upper and lower ends of the valve body; a flue gas inlet connector disposed on the lower valve cover and connected sequentially to the lower valve cover and the valve core, wherein the flue gas inlet connector is configured to connect to the sampling probe; a flue gas outlet connector disposed on the upper valve cover and connected sequentially to the upper valve cover and the valve core, wherein the flue gas outlet connector is configured to connect to a measuring cell; a backflush connector disposed on the lower valve cover and connected sequentially to the lower valve cover and the valve core, wherein the backflush connector is configured to connect to compressed gas; the valve core includes an empty tube and a float ball, the empty tube being a tapered empty tube with an upper diameter larger than the lower diameter, and the float ball being configured to float up and down within the empty tube; the inner diameter of the channel connecting the upper valve cover and the valve core is smaller than the diameter of the float ball.

[0007] Furthermore, it also includes a cleaning connector, which is disposed on the upper valve cover and connected in sequence to the upper valve cover and the valve core, and the cleaning connector is configured to connect to compressed gas.

[0008] Furthermore, it also includes a heating rod, and the valve body is provided with a cavity to accommodate the heating rod.

[0009] Preferably, the hollow tube is a transparent glass tube.

[0010] Furthermore, an observation window is provided on the valve body, and the observation window is set to correspond to the empty pipe.

[0011] Preferably, the upper valve cover includes an upper end cap and an upper end transition cap, the upper end transition cap is installed between the upper end cap and the valve body, a first upper end sealing ring is provided between the upper end cap and the upper end transition cap, and a second upper end sealing ring is provided between the upper end transition cap and the valve body; the lower valve cover includes a lower end cap and a lower end transition cap, the lower end transition cap is installed between the lower end cap and the valve body, a first lower end sealing ring is provided between the lower end cap and the lower end transition cap, and a second lower end sealing ring is provided between the lower end transition cap and the valve body.

[0012] Furthermore, the upper end cap near the valve body is configured as a flared opening that is smaller at the top and larger at the bottom. The upper diameter of the flared opening is smaller than the diameter of the float ball, and the lower diameter of the flared opening is larger than the diameter of the float ball. The upper end of the empty tube passes through the upper transition cap and rests against the bottom of the flared opening of the upper end cap.

[0013] Furthermore, the lower end cap is provided with a conical protrusion at one end near the valve body. The conical protrusion has a cavity that communicates with both the flue gas inlet connector and the backflush connector. The lower end of the empty pipe passes through the lower end transition cover and rests against the top of the lower end cap, and the conical protrusion is accommodated inside the empty pipe.

[0014] Preferably, the cleaning connector is located at the top of the upper cover, and the flue gas outlet connector is located on the side of the upper cover.

[0015] Preferably, the backflush connector is located at the bottom of the lower end cover, and the flue gas inlet connector is located on the side of the lower end cover.

[0016] This invention uses a float ball and an empty tube as the valve core to control the on / off state of the valve body. The empty tube is designed as a tapered tube with an upper inner diameter larger than a lower inner diameter. This ensures that when a low flow rate of gas passes through the valve core during sampling, the float ball remains in the middle of the inner tube, guaranteeing a stable flow of the gas to be tested and meeting the requirements of normal measurement. However, when a large amount of compressed gas at higher pressure enters the empty tube, the float ball rises and seals the channel connecting the upper valve cover and the valve core, disconnecting the measuring cell from the backflush connector. A large amount of compressed gas is then used to directly purge the sampling probe through the flue gas inlet connector, preventing high-pressure gas from entering the measuring cell and ensuring the safety of the precision optical components inside the measuring cell. The overall structure is simple and compact, requiring no additional heat insulation mechanism. The valve core uses a mechanical mechanism to operate the on / off state of each circuit within the valve, making it safer and more reliable. Attached Figure Description

[0017] Figure 1 Front view of the invention;

[0018] Figure 2 for Figure 1 A sectional view;

[0019] Figure 3 This is an exploded view of the present invention.

[0020] Figure 4 This is a cross-sectional isometric view of the present invention.

[0021] In the diagram: 1. Valve body; 11. Observation window;

[0022] 2. Valve core; 21. Empty pipe; 22. Float ball;

[0023] 3. Upper valve cover; 31. Upper end cover; 311. Flared mouth; 32. Upper end transition cover; 33. First upper end sealing ring; 34. Second upper end sealing ring.

[0024] 4. Lower valve cover; 41. Lower end cover; 411. Conical protrusion; 42. Lower end transition cover; 43. First lower end sealing ring; 44. Second lower end sealing ring.

[0025] 5. Flue gas inlet connector;

[0026] 6. Flue gas outlet connector;

[0027] 7. Backflush connector;

[0028] 8. Clean the connector;

[0029] 9. Heating rod. Detailed Implementation

[0030] The invention will now be further described with reference to the accompanying drawings.

[0031] like Figures 1 to 4 As shown, a backflush valve for a flue gas sampling probe includes a valve body 1; a valve core 2 disposed within the valve body 1; an upper valve cover 3 and a lower valve cover 4 disposed at the upper and lower ends of the valve body 1, respectively; a flue gas inlet connector 5 disposed on the lower valve cover, the flue gas inlet connector 5 being sequentially connected to the lower valve cover 4 and the valve core 2, and the flue gas inlet connector 5 being configured to connect to the sampling probe; and a flue gas outlet connector 6 disposed on the upper valve cover 3, the flue gas outlet connector 6 being sequentially connected to the upper valve cover 3 and the valve core 2. Furthermore, the flue gas outlet connector 6 is configured to connect to the measuring cell; the backflush connector 7 is provided on the lower valve cover 4, and the backflush connector 7 is connected to the lower valve cover 4 and the valve core 2 in sequence, and the backflush connector 7 is configured to connect to compressed gas; the valve core 2 includes an empty tube 21 and a float ball 22, the empty tube 21 is a tapered empty tube with an upper diameter larger than the lower diameter, and the float ball 22 is configured to float up and down in the empty tube 21; the inner diameter of the channel connecting the upper valve cover 3 and the valve core 2 is smaller than the diameter of the float ball 22.

[0032] In this embodiment, the backflush connector 7 can be connected to compressed gas via the first solenoid valve. When the first solenoid valve is de-energized, the pipeline between the compressed gas and the backflush connector 7 is closed. At this time, the flue gas to be monitored enters the measuring cell from the flue gas inlet connector 5 at a low flow rate (typically 0.5-10 LPM) sequentially through the lower valve cover 4, the empty pipe 21, the upper valve cover 3, and the flue gas outlet connector 6. Due to the low gas flow rate and pressure, and because the empty pipe 21 is a tapered empty pipe with a larger upper diameter than a lower diameter, the float ball 22 remains in the middle of the inner pipe 21 under the action of the fluid, ensuring the stable passage of the gas to be detected and meeting the requirements of normal measurement. When it is necessary to purge the probe... When the filter is activated, the first solenoid valve is energized, and the pipeline between the backflush connector 7 and the compressed gas is connected. A large amount of compressed gas (0.4-0.8 MPa) enters the empty pipe 21 through the backflush connector 7 and the lower valve cover 4 in sequence. Since the pressure and flow rate are far beyond the normal, the float ball 22 is forced to rise, blocking the channel between the upper valve cover 3 and the valve core 2. At this time, the measuring cell is effectively disconnected from the backflush connector 7, and a large amount of compressed gas directly purges the sampling probe through the flue gas inlet connector 5, avoiding the entry of high-pressure gas into the measuring cell and ensuring the safety of the precision optical components in the measuring cell.

[0033] Under certain harsh operating conditions, the float ball may become contaminated and stick to the wall of the empty pipe or the upper and lower valve covers. To address this issue, as a further improved embodiment, such as... Figures 1 to 4As shown, a backflush valve for a flue gas sampling probe also includes a cleaning connector 8. The cleaning connector 8 is disposed on the upper valve cover 3 and is sequentially connected to the upper valve cover 3 and the valve core 2. The cleaning connector 8 is configured to connect to compressed gas. In this embodiment, the cleaning connector 8 can be connected to compressed gas through a second solenoid valve. At this time, by alternately switching the first and second solenoid valves on and off, the compressed gas alternately blows forcefully onto the upper and lower parts of the float ball, forcing the float ball to move up and down reciprocally and break free from the sticky state.

[0034] When high-temperature flue gas encounters an empty pipe, low-temperature condensation may occur, causing the float ball to adhere to the inner pipe wall. To avoid this situation, as a further improved embodiment, such as... Figures 1 to 3 As shown, a backflush valve for use with a flue gas sampling probe also includes a heating rod 9, and the valve body 1 is provided with a cavity for accommodating the heating rod 9.

[0035] In a preferred embodiment, the hollow tube 21 can be a transparent glass tube.

[0036] As a further improved embodiment, such as Figure 1 and Figure 3 As shown, an observation window 11 is also provided on the valve body 1, and the observation window 11 is set correspondingly to the empty tube 21. With the above improvements, and in conjunction with the transparent empty tube 21, the working status of the float ball 22 inside the empty tube 21 can be observed at any time.

[0037] To enhance the sealing performance of the upper and lower valve covers and facilitate disassembly and assembly, in this embodiment, the upper valve cover 3 includes an upper end cap 31 and an upper end transition cap 32. The upper end transition cap 32 is installed between the upper end cap 31 and the valve body 1. A first upper end sealing ring 33 is provided between the upper end cap 31 and the upper end transition cap 32, and a second upper end sealing ring 34 is provided between the upper end transition cap 32 and the valve body 1. The lower valve cover 4 includes a lower end cap 41 and a lower end transition cap 42. The lower end transition cap 42 is installed between the lower end cap 41 and the valve body 1. A first lower end sealing ring 43 is provided between the lower end cap 41 and the lower end transition cap 42, and a second lower end sealing ring 44 is provided between the lower end transition cap 42 and the valve body 1.

[0038] As a further improved embodiment, the upper end cap 31 is configured with a flared opening 311 near the valve body 1, with the upper diameter smaller than the lower diameter. The upper diameter of the flared opening 311 is smaller than the diameter of the float ball 22, and the lower diameter is larger than the diameter of the float ball 22. The upper end of the empty pipe 21 passes through the upper transition cover 32 and rests against the bottom of the flared opening 311 of the upper end cap 31. When a large amount of compressed gas enters the empty pipe 21, the float ball 22 is forced to rise and block the flared opening 311 of the upper end cap, improving the sealing effect. The lower end cap 41 is provided with a conical protrusion II 411 near the valve body 1. The conical protrusion II 411 has a cavity that communicates with both the flue gas inlet connector 5 and the backflush connector 7. The lower end of the empty pipe 21 passes through the lower transition cover 42 and rests against the top of the lower end cap 41. The conical protrusion II 411 is accommodated within the empty pipe 21, thereby ensuring that gas enters the empty pipe 21 directly and reducing pressure loss.

[0039] In the most preferred embodiment, the cleaning connector 8 is located at the top of the upper cover 31, and the flue gas outlet connector 6 is located on the side of the upper cover 31. The backflush connector 7 is located at the bottom of the lower cover 41, and the flue gas inlet connector 5 is located on the side of the lower cover 41. Under both backflush and cleaning conditions, compressed gas can be directly introduced into the empty pipe, minimizing pressure loss.

[0040] The working principle of a backflush valve applied to a flue gas sampling probe is described in detail using the preferred embodiment as follows:

[0041] Sampling conditions: The first and second solenoid valves are disconnected, and the pipelines between the compressed gas and the backflush connector 7 and between the compressed gas and the cleaning connector 8 are closed. The flue gas to be monitored enters the measuring cell from the flue gas inlet connector 5 at a low flow rate (typically 0.5-10 LPM) through the lower valve cover 4, the empty pipe 21, the upper valve cover 3, and the flue gas outlet connector 6.

[0042] Backflush operation: The first solenoid valve is energized, and the pipeline between the backflush connector 7 and the compressed gas is connected. A large amount of compressed gas (0.4-0.8MPa) enters the empty pipe 21 through the backflush connector 7 and the lower valve cover 4 in sequence. The float ball 22 is forced to rise and block the horn mouth 311, sealing the channel between the upper valve cover 3 and the valve core 2. The compressed gas directly blows the sampling probe through the flue gas inlet connector 5.

[0043] Cleaning operation: When the float ball 22 is observed to be adhered to the inner wall of the empty pipe 21 through the observation window 11, the first solenoid valve and the second solenoid valve are alternately opened and closed, so that the compressed gas enters the empty pipe 22 from the upper and lower parts of the float ball 21 through the cleaning joint 8 and the backflush joint 7 respectively, forcing the float ball 21 to move up and down back and forth, and get rid of the adhered state.

[0044] In the description of this invention, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0045] In this invention, unless otherwise explicitly specified and limited, for example, it can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two elements or an interaction between two elements. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A backflush valve for use in a flue gas sampling probe, characterized in that, include: Valve body; The valve core is located inside the valve body; The upper valve cover and lower valve cover are respectively installed at the upper and lower ends of the valve body; A flue gas inlet connector is located on the lower valve cover and is connected to the lower valve cover and the valve core in sequence. The flue gas inlet connector is configured to connect to a sampling probe. A flue gas outlet connector is located on the upper valve cover and is connected to the upper valve cover and the valve core in sequence. The flue gas outlet connector is configured to connect to the measuring cell. A backflush connector is located on the lower valve cover and is connected in sequence to the lower valve cover and the valve core. The backflush connector is configured to connect to compressed gas. The valve core includes an empty tube and a float ball. The empty tube is a tapered tube with an upper diameter larger than the lower diameter. The float ball is configured to float up and down inside the empty tube. The inner diameter of the channel connecting the upper valve cover and the valve core is smaller than the diameter of the float ball.

2. The backflush valve applied to a flue gas sampling probe as described in claim 1, characterized in that, It also includes a cleaning connector, which is disposed on the upper valve cover and connected in sequence to the upper valve cover and the valve core, and the cleaning connector is configured to connect to compressed gas.

3. The backflush valve applied to a flue gas sampling probe as described in claim 1, characterized in that, It also includes a heating rod, and the valve body is provided with a cavity to accommodate the heating rod.

4. The backflush valve applied to a flue gas sampling probe as described in claim 1, characterized in that, The empty tube is a transparent glass tube.

5. The backflush valve applied to a flue gas sampling probe as described in claim 4, characterized in that, An observation window is also provided on the valve body, and the observation window is set to correspond to the empty pipe.

6. The backflush valve applied to a flue gas sampling probe as described in any one of claims 1 to 5, characterized in that, The upper valve cover includes an upper end cap and an upper end transition cap. The upper end transition cap is installed between the upper end cap and the valve body. A first upper end sealing ring is provided between the upper end cap and the upper end transition cap, and a second upper end sealing ring is provided between the upper end transition cap and the valve body. The lower valve cover includes a lower end cap and a lower end transition cap. The lower end transition cap is installed between the lower end cap and the valve body. A first lower end sealing ring is provided between the lower end cap and the lower end transition cap, and a second lower end sealing ring is provided between the lower end transition cap and the valve body.

7. The backflush valve applied to a flue gas sampling probe as described in claim 6, characterized in that, The upper end cap is designed with a flared opening that is smaller at the top and larger at the bottom than at the bottom. The upper diameter of the flared opening is smaller than the diameter of the float ball, and the lower diameter of the flared opening is larger than the diameter of the float ball. The upper end of the empty tube passes through the upper transition cap and rests against the bottom of the flared opening of the upper end cap.

8. The backflush valve applied to a flue gas sampling probe as described in claim 7, characterized in that, The lower end cap is provided with a conical protrusion at one end near the valve body. The conical protrusion has a cavity that is connected to both the flue gas inlet connector and the backflush connector. The lower end of the empty pipe passes through the lower end transition cover and rests against the top of the lower end cap, and the conical protrusion is accommodated inside the empty pipe.

9. The backflush valve for a flue gas sampling probe as described in claim 7, characterized in that, The cleaning connector is located at the top of the upper cover, and the flue gas outlet connector is located on the side of the upper cover.

10. The backflush valve for a flue gas sampling probe as described in claim 8, characterized in that, The backflush connector is located at the bottom of the lower end cover, and the flue gas inlet connector is located on the side of the lower end cover.

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