Flue gas sampling filter and flue gas sampling device

Abstract

The utility model provides a flue gas sampling filter and a flue gas sampling device, the flue gas sampling filter comprises: an inner filter cartridge, which is provided with a first cavity in a penetrating manner, and is provided with filter holes in the circumferential direction in a penetrating manner; the outer cylinder is sleeved with the inner filter cylinder; a first end cover and a second end cover, the first end cover blocks a gap between the first end of the inner filter cylinder and the first end of the outer cylinder, the second end cover blocks a gap between the second end of the inner filter cylinder and the second end of the outer cylinder, a second cavity is defined by the outer cylinder, the inner filter cylinder, the first end cover and the second end cover, and the first end cover, the second end cover or the outer cylinder is provided with a back-blowing ash discharge port in a penetrating mode. A check valve is mounted in the back-blowing ash discharge port; the gas collecting pipe is communicated with the first end of the inner filter cylinder, and the cross section area of the gas collecting pipe is gradually increased in the direction far away from the inner filter cylinder; the sampling tube penetrates through the outer cylinder and is communicated with the second cavity. By adopting the sampling device, the sampling probe is prevented from being in direct contact with flue gas with dust, the sampling probe is prevented from being blocked by dust, and the service life of the sampling probe is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of flue gas filtration technology, specifically to a flue gas sampling filter and a flue gas sampling device. Background Technology

[0002] Flue gas emissions must strictly comply with national emission standards, requiring the use of sampling probes in flue gas emission ducts to detect and analyze the content of gases such as NOx and SO2. Current technology involves directly inserting the sampling probe into the flue to sample and test the flue gas. However, flue ducts contain a large amount of dust and other impurities, and directly inserting the sampling probe into the flue can easily lead to probe blockage. Utility Model Content

[0003] In view of this, the present invention provides a flue gas sampling filter and a flue gas sampling device to solve the above-mentioned technical problems.

[0004] The flue gas sampling filter provided by this utility model includes:

[0005] An inner filter cartridge, wherein a first cavity is provided through the inner filter cartridge and a filter hole is provided through the inner filter cartridge in the circumferential direction;

[0006] An outer cylinder, the outer cylinder is sleeved with the inner filter cylinder;

[0007] A first end cap and a second end cap are provided. The first end cap blocks the gap between the inner filter cartridge and the first end of the outer cylinder, and the second end cap blocks the gap between the inner filter cartridge and the second end of the outer cylinder. A second cavity is formed between the outer cylinder, the inner filter cartridge, the first end cap, and the second end cap. A backflushing ash discharge port is provided through the first end cap, the second end cap, or the outer cylinder. A check valve is installed in the backflushing ash discharge port.

[0008] A gas collecting pipe is connected to the first end of the inner filter cylinder, and the cross-sectional area of ​​the gas collecting pipe gradually increases in the direction away from the inner filter cylinder.

[0009] A sampling tube that penetrates the outer cylinder and connects to the second cavity.

[0010] Optionally, the flue gas sampling filter further includes a compressed air source, which is connected to the backflushing ash discharge port via an air supply pipe, and an electrically controlled valve is provided on the air supply pipe.

[0011] Optionally, the flue gas sampling filter further includes:

[0012] A differential pressure sensor, wherein the first probe of the differential pressure sensor is disposed in the first cavity, and the second probe of the differential pressure sensor is disposed in the second cavity;

[0013] The controller has its input terminal communicatively connected to the output terminal of the differential pressure sensor, and its output terminal communicatively connected to the control terminal of the electronically controlled valve.

[0014] Optionally, the flue gas sampling filter further includes an alarm, the input of which is communicatively connected to the output of the controller.

[0015] Optionally, the flue gas sampling filter further includes a display screen, the input of which is communicatively connected to the output of the controller.

[0016] Optionally, a first sealing element is provided between the first end cap and the inner filter cartridge, and between the first end cap and the outer cartridge.

[0017] Optionally, a second sealing element is provided between the second end cap and the inner filter cartridge, and between the second end cap and the outer cartridge.

[0018] Optionally, a third sealing element is provided between the sampling tube and the outer cylinder.

[0019] Optionally, the outer cylinder is made of stainless steel.

[0020] This utility model also provides a flue gas sampling device, including a sampling probe and a flue gas sampling filter as described in any of the above claims, wherein the sampling tube of the flue gas sampling filter is connected to the sampling probe.

[0021] The technical solution provided by this utility model has at least the following beneficial effects compared with the prior art:

[0022] The flue gas sampling filter and sampling device of this invention allow flue gas to enter the inner filter cartridge through the gas collecting pipe, with some of the flue gas passing through the inner filter cartridge. After being filtered for dust by the inner filter cartridge, the flue gas enters the second chamber and then enters the sampling probe through the sampling tube. In other words, the dust in the flue gas has been filtered by the inner filter cartridge before entering the sampling probe, thus avoiding direct contact between the sampling probe and the dusty flue gas, preventing the sampling probe from being blocked by dust, and helping to extend the service life of the sampling probe. Attached Figure Description

[0023] Figure 1 This is a perspective view of a flue gas sampling filter according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of a flue gas sampling device according to an embodiment of the present invention.

[0025] Figure label:

[0026] 1: Inner filter cartridge; 2: Outer cartridge; 3: First end cap; 4: Second end cap; 5: Gas collecting pipe; 6: Sampling pipe; 7: Backflush ash discharge port; 8: Sampling probe. Detailed Implementation

[0027] The embodiments of this utility model will be further described below with reference to the accompanying drawings. In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the purpose of simplifying the description of this utility model. They do not indicate or imply that the device or component 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 utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0028] Figure 1 This is a perspective view of a flue gas sampling filter according to an embodiment of the present invention. Figure 1 As shown, the flue gas sampling filter includes an inner filter cylinder 1, an outer cylinder 2, a first end cap 3, a second end cap 4, a gas collecting pipe 5, and a sampling pipe 6. The inner filter cylinder 1 has a first cavity extending through it, and filter holes are circumferentially extending through it. The outer cylinder 2 is fitted over the inner filter cylinder 1. The first end cap 3 seals the gap between the first ends of the inner filter cylinder 1 and the outer cylinder 2, and the second end cap 4 seals the gap between the second ends of the inner filter cylinder 1 and the outer cylinder 2. A second cavity is formed between the outer cylinder 2, the inner filter cylinder 1, the first end cap 3, and the second end cap 4. A backflush ash discharge port 7 is extending through the first end cap 3, the second end cap 4, or the outer cylinder 2, and a check valve is installed inside the backflush ash discharge port 7. The gas collecting pipe 5 is connected to the first end of the inner filter cylinder 1, and the cross-sectional area of ​​the gas collecting pipe 5 gradually increases in the direction away from the inner filter cylinder 1. The sampling pipe 6 extends through the outer cylinder 2 and is connected to the second cavity.

[0029] In use, the sampling tube 6 is connected to the sampling probe 8 used to detect the gas composition and content. The entire flue gas sampling filter is placed in the flue, and the gas collecting pipe 5 is oriented towards the source of the flue gas. The flue gas enters the gas collecting pipe 5. Due to the structure of the gas collecting pipe 5, the cross-sectional area gradually decreases in the direction away from the source of the flue gas, which increases the flue gas flow rate, prevents dust from depositing on the surface of the gas collecting pipe 5, and allows the flue gas to quickly enter the inner filter cartridge 1. After entering the inner filter cartridge 1, part of the flue gas is discharged directly from the other end of the inner filter cartridge 1, and part of it passes through the circumference of the inner filter cartridge 1. After the dust is filtered by the inner filter cartridge 1, the relatively clean flue gas enters the second cavity between the inner filter cartridge 1 and the outer cylinder 2, and further enters the sampling tube 6 which is connected to the second cavity. Finally, it enters the sampling probe 8 which is connected to the sampling tube 6. The sampling probe 8 then detects and analyzes the relatively clean flue gas after the dust filtration. After a period of use, the dust adhering to the inner filter cartridge 1 increases. In order to prevent the dust from clogging the filter holes on the inner filter cartridge 1, high-pressure gas is delivered to the second chamber through the back-blowing ash discharge port 7. The high-pressure gas blows towards the outer wall of the inner filter cartridge 1, blowing off the dust adhering to the flue gas on the inner filter cartridge 1 and causing it to fall into the inner filter cartridge 1. The dust is then discharged through the other end along with the flue gas entering the inner filter cartridge 1.

[0030] The flue gas sampling filter of this utility model allows flue gas to enter the inner filter cartridge 1 through the gas collecting pipe 5, and part of the flue gas passes through the inner filter cartridge 1. After being filtered for dust by the inner filter cartridge 1, the flue gas enters the second chamber and then enters the sampling probe 8 through the sampling pipe 6. That is, before the flue gas enters the sampling probe 8, the dust in the flue gas has been filtered by the inner filter cartridge 1, thereby avoiding direct contact between the sampling probe 8 and the dusty flue gas, preventing the sampling probe 8 from being blocked by dust, and helping to extend the service life of the sampling probe 8.

[0031] like Figure 1 As shown, in this embodiment, the inner filter cylinder 1 and the outer cylinder 2 are coaxially fitted hollow cylinders. The inner diameter of the inner filter cylinder 1 is smaller than the inner diameter of the outer cylinder 2, and a certain gap is maintained between them. The inner filter cylinder 1 has filter holes uniformly opened throughout its circumference. The first end cap 3 and the second end cap 4 are both annular structures. The first end cap 3 is used for sealing. Figure 1 The gap between the outer cylinder 2 and the upper end of the inner filter cylinder 1 is sealed by the second end cap 4. Figure 1The gap between the outer cylinder 2 and the lower end of the inner filter cylinder 1 prevents the flue gas in the flue from directly entering the space between the outer cylinder 2 and the inner filter cylinder 1. The gas collecting pipe 5 is generally conical, with the angle between the hypotenuse of its cross-section and the horizontal plane set at 40°-60°. The end with the smaller cross-sectional area is connected to the upper end of the inner filter cylinder 1, so that the flue gas entering the gas collecting pipe 5 is compressed and accelerated by the conical structure and enters the first cavity of the inner filter cylinder 1. The sampling pipe 6 is a hollow cylindrical pipe that passes through the outer cylinder 2 and extends into the second cavity between the outer cylinder 2 and the inner filter cylinder 1. It is used to transport the flue gas after dust filtration to the sampling probe 8. In this embodiment, the backflush ash discharge port 7 is opened on the second end cap 4 away from the gas collecting pipe 5, and a check valve is installed in the backflush ash discharge port 7, so that high-pressure gas can be transported to the second cavity through the backflush ash discharge port 7, while the flue gas in the second cavity cannot be discharged through the backflush ash discharge port 7. Depending on the actual application, the backflushing ash discharge port 7 can also be opened on the first end cover 3 and the outer cylinder 2. Multiple backflushing ash discharge ports 7 can also be set. The dimensions of the inner filter cylinder 1 and the outer cylinder 2 can be matched and adjusted. The inclination angle and extension length of the inclined side of the gas collecting pipe 5 can also be adjusted. Depending on the different conditions of filtering flue gas, the size and opening density of the filter holes opened through the inner filter cylinder 1 can be appropriately adjusted.

[0032] Optionally, the flue gas sampling filter also includes a compressed air source (not shown), which is connected to the backflushing ash discharge port 7 via an air supply pipe, and an electrically controlled valve is installed on the air supply pipe. The compressed air source facilitates the supply of high-pressure gas to the second chamber at any time to purge the inner filter cartridge 1 and prevent dust adhering to the inner filter cartridge 1 from clogging the filter holes.

[0033] After the flue gas sampling filter has been used for a period of time, dust will be attached to the inner filter cartridge 1. When the electric control valve is opened, the compressed air source will be delivered to the second chamber through the air supply pipe and blow off the dust on the inner filter cartridge 1. The compressed air source can be any stable air source, such as air or nitrogen. The timing of opening the electric control valve can be determined according to the dust concentration in the flue gas and working experience, or the opening time interval can be fixed.

[0034] Optionally, the flue gas sampling filter also includes a differential pressure sensor (not shown) and a controller (not shown). The first probe of the differential pressure sensor is disposed in the first chamber, and the second probe of the differential pressure sensor is disposed in the second chamber. The input terminal of the controller is communicatively connected to the output terminal of the differential pressure sensor, and the output terminal of the controller is communicatively connected to the control terminal of the electronically controlled valve. This configuration allows for real-time determination of whether the inner filter cartridge 1 is clogged based on the monitoring data from the differential pressure sensor, and timely control of the electronically controlled valve to open, introducing high-pressure gas to purge the dust adhering to the inner filter cartridge 1.

[0035] The first probe of the differential pressure sensor monitors the first pressure value of the flue gas in the first chamber, and the second probe monitors the second pressure value of the flue gas after dust filtration in the second chamber. The real-time differential pressure value is obtained based on the first and second pressure values ​​and transmitted to the controller. When the second pressure value is significantly lower than the first pressure value, it indicates that the amount of flue gas entering the second chamber through the first chamber is too small, meaning the filter holes on the inner filter cartridge 1 are blocked by dust, preventing the flue gas from smoothly entering the second chamber. The controller has a pre-stored set differential pressure value indicating blockage of the inner filter cartridge 1. The controller receives the real-time differential pressure value transmitted by the differential pressure sensor and compares it with the set differential pressure value. When the real-time differential pressure value is greater than the set differential pressure value, it indicates that the filter cartridge is blocked by dust. At this time, the controller controls the electronic control valve to open, and compressed air is delivered to the second chamber through the air supply pipe to blow away the dust on the inner filter cartridge 1, causing the dust to fall into the first chamber and be discharged with the flue gas through the end of the inner filter cartridge 1 away from the gas collecting pipe 5. Differential pressure sensors are a mature existing technology, and their specific structure and working principle will not be described in detail here.

[0036] Optionally, the flue gas sampling filter also includes an alarm (not shown), the input of which is communicatively connected to the output of the controller. The alarm is set so that when the controller receives a real-time differential pressure value from the differential pressure sensor that exceeds a set differential pressure value, indicating that the inner filter cartridge 1 is clogged with dust, the controller activates the alarm to alert personnel that the inner filter cartridge 1 is clogged. The alarm is located outside the flue and can be either a voice alarm or a light alarm.

[0037] Optionally, the flue gas sampling filter also includes a display screen, the input of which is communicatively connected to the output of the controller. The display screen is located outside the flue, allowing the controller to transmit received real-time pressure difference values ​​for display, enabling staff to intuitively understand the gas pressure difference between the first and second chambers.

[0038] Optionally, a first sealing element is provided between the first end cap 3 and the inner filter cartridge 1, and between the first end cap 3 and the outer cylinder 2. This arrangement uses the first sealing element to seal the gaps between the first end cap 3 and the inner filter cartridge 1 and the outer cylinder 2, preventing the flue gas after filtering dust from entering the second cavity and escaping through the gaps between the first end cap 3 and the inner filter cartridge 1 and the outer cylinder 2, thus preventing it from being smoothly delivered to the sampling tube 6.

[0039] Optionally, second sealing elements are provided between the second end cap 4 and the inner filter cartridge 1, and between the second end cap 4 and the outer cylinder 2. This arrangement uses the second sealing elements to seal the gaps between the second end cap 4 and the inner filter cartridge 1 and the outer cylinder 2, preventing the filtered dust-laden flue gas from entering the second cavity and escaping through the gaps between the second end cap 4 and the inner filter cartridge 1 and the outer cylinder 2, thus preventing it from being smoothly delivered to the sampling tube 6.

[0040] Optionally, a third sealing element is provided between the sampling tube 6 and the outer cylinder 2. This arrangement uses the third sealing element to seal the gap between the sampling tube 6 and the outer cylinder 2, preventing the flue gas after filtering dust from entering the second cavity and escaping through the gap between the sampling tube 6 and the outer cylinder 2, thus preventing it from being smoothly delivered to the sampling tube 6.

[0041] Optionally, the outer cylinder 2 is made of stainless steel. Stainless steel is heat-resistant and suitable for temperatures above 100°C, making it suitable for flue environments.

[0042] Figure 2 This is a schematic diagram of a flue gas sampling device according to one embodiment of the present invention. Figure 2 As shown, this utility model also provides a flue gas sampling device, including a sampling probe 8, and a flue gas sampling filter as described in any of the above embodiments, wherein the sampling tube 6 of the flue gas sampling filter is connected to the sampling probe 8.

[0043] Using the flue gas sampling device of this utility model, the flue gas enters the inner filter cartridge 1 through the gas collecting pipe 5, and part of the flue gas passes through the inner filter cartridge 1. After being filtered for dust by the inner filter cartridge 1, the flue gas enters the second chamber and then enters the sampling probe 8 through the sampling pipe 6. That is, before the flue gas enters the sampling probe 8, the dust in the flue gas has been filtered by the inner filter cartridge 1, thereby avoiding the sampling probe 8 from directly contacting the dusty flue gas, preventing the sampling probe 8 from being blocked by dust, and helping to extend the service life of the sampling probe 8.

[0044] In this embodiment, the sampling tube 6 is threadedly connected to the sampling probe 8. Other detachable connection methods can also be used depending on actual needs. The sampling probe 8 is a mature existing technology, and its specific structure and the principle of detecting gas component content will not be described in detail here.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A flue gas sampling filter, characterized in that, It comprises: an inner filter cartridge, which is provided with a first cavity through the whole, and a filter hole through the whole in the circumferential direction; an outer cylinder, which is sleeved on the inner filter cartridge; a first end cover and a second end cover, the first end cover seals the gap between the first end of the inner filter cartridge and the outer cylinder, and the second end cover seals the gap between the second end of the inner filter cartridge and the outer cylinder, the second cavity is enclosed between the outer cylinder, the inner filter cartridge, the first end cover and the second end cover, the back blowing and ash discharging port is provided through the first end cover, the second end cover or the outer cylinder, and the check valve is installed in the back blowing and ash discharging port; a gas collecting pipe, which communicates with the first end of the inner filter cartridge, and the cross-sectional area of the gas collecting pipe gradually increases in the direction away from the inner filter cartridge; a sampling pipe, which penetrates the outer cylinder and communicates with the second cavity.

2. The flue gas sampling filter according to claim 1, characterized in that, It further comprises: a compressed gas source, which communicates with the back blowing and ash discharging port through a gas feeding pipe, and the electric control valve is arranged on the gas feeding pipe.

3. The flue gas sampling filter according to claim 2, characterized in that, It further comprises: a differential pressure sensor, the first probe of which is arranged in the first cavity, and the second probe of which is arranged in the second cavity; a controller, the input end of which is communicatively connected with the output end of the differential pressure sensor, and the output end of which is communicatively connected with the control end of the electric control valve.

4. The flue gas sampling filter according to claim 3, characterized in that, It further comprises: an alarm, the input end of which is communicatively connected with the output end of the controller.

5. The flue gas sampling filter according to claim 3 or 4, characterized in that, It further comprises: a display screen, the input end of which is communicatively connected with the output end of the controller.

6. The flue gas sampling filter according to any one of claims 1-4, characterized in that: first sealing members are arranged between the first end cover and the inner filter cartridge, and between the first end cover and the outer cylinder, respectively.

7. The flue gas sampling filter according to any one of claims 1-4, characterized in that: second sealing members are arranged between the second end cover and the inner filter cartridge, and between the second end cover and the outer cylinder, respectively.

8. The flue gas sampling filter according to any one of claims 1-4, characterized in that: a third sealing member is arranged between the sampling pipe and the outer cylinder.

9. The flue gas sampling filter according to any one of claims 1-4, characterized in that: the outer cylinder is made of stainless steel material.

10. A flue gas sampling device comprising a sampling probe, characterised in that, It further comprises the flue gas sampling filter according to any one of claims 1-9, and the sampling pipe of the flue gas sampling filter is connected with the sampling probe.

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