Detection probe with replaceable filter element

Abstract

The utility model belongs to the technical field of test equipment, and particularly relates to a detection probe with a replaceable filter element, which comprises a probe main body and a filter element assembly detachably mounted at the rear end of the probe main body, and the filter element assembly comprises an integrated filter element base and a sintered filter element; the integrated filter element base is sequentially provided with a filter body fixing section, a coaxial guiding and positioning section, a flange butt-joint disc and a gas circuit connecting section from front to back in the flowing direction of detected gas; the end face of the rear end of the sintered filter element is fixedly connected with the filter body fixing section, an opening in the rear end of the filter body fixing section is arranged in the coaxial guiding and positioning section in a sleeving manner and forms sealed rigid fixation, the coaxial guiding and positioning section is fixedly connected with the flange butt-joint disc, and the flange butt-joint disc is fixedly connected with the gas circuit connecting section; a butt joint flange completely matched with the flange butt joint disc is arranged on the end face of the rear end of the probe body. The device can realize quick replacement of the filter element, improve the maintenance efficiency and enhance the operation stability of equipment.

Description

Technical Field

[0001] This utility model belongs to the field of testing equipment technology, specifically relating to a detection probe with a replaceable filter element. Background Technology

[0002] In the detection of industrial flue gas, process waste gas, and other gases, the gases being tested typically contain large amounts of dust, particulate matter, tar, and corrosive components. If these gases directly enter the detection and analysis unit, they can easily cause blockage of the sampling gas path, contamination of the detection sensor, or even permanent damage. Therefore, the front end of the detection probe usually needs to be equipped with a filter element to pre-treat the gas being tested by dust removal. Existing gas detection probes with filtration functions mostly have built-in or external screw-on filter elements. Built-in filter elements require the entire filter element to be embedded inside the probe cylinder. Replacing the filter element requires completely disassembling the probe end housing and disconnecting the internal sampling gas path and electrical wiring, which is cumbersome and time-consuming. External screw-on filter elements are mostly connected to the probe body by screwing on threads. During disassembly and assembly, the filter element body needs to be rotated circumferentially, which can easily cause cracks in brittle filter elements such as sintered metals and ceramics, and can also easily lead to thread stripping and jamming. Meanwhile, existing probes mostly use single-seal, multi-component spliced ​​filter bases, which are prone to seal failure under high-temperature alternating and strong vibration industrial conditions, leading to distorted test data and corrosion and short circuits in electrical components. Regarding the filter structure, existing probes often use end-face air intake filtration, relying solely on the end face of the filter element as the filtration working surface. This results in a small effective filtration area, allowing dust particles in the measured gas to accumulate rapidly on the end face, causing filter blockage and requiring frequent cleaning, maintenance, and replacement, thus shortening the lifespan. Furthermore, existing probes are mostly integrated fixed structures, making it impossible to replace damaged parts individually, resulting in high spare parts and maintenance costs and poor adaptability to operating conditions.

[0003] Chinese patent CN216050965U discloses a replaceable probe filter element for a flue gas dilution sampling probe, comprising a filter element shell, an inner core, a bottom cover, a heating pipe, a top cover, and a disassembly device. A conical cylinder is installed on the left side of the filter element shell, and a threaded hole is formed on the right side wall of the filter element shell. The bottom cover is threadedly connected to the inside of this threaded hole. The inner core is installed inside the filter element shell, and a heating pipe, which is a spiral pipe, is installed on the outer side wall of the inner core. An inlet and an outlet are respectively formed on the outer side wall of the filter element shell, and both ends of the heating pipe extend outwards from the inlet and outlet, respectively. Top covers are installed at both ends of the heating pipe. This patent adds a conical sleeve to the outside of the probe pipe and installs a conical cylinder on the filter element shell, achieving a quick filter element replacement function and improving filter element replacement efficiency. However, the disassembly device in this patent includes multiple precision-fitting components such as a driving gear, driven gear, rotating rod, fixed sleeve, movable sleeve, and circular slide rail. Flue gas detection sites are often harsh environments characterized by high temperatures, high dust levels, high corrosion, and strong vibrations. Dust can easily enter the gear meshing gaps and threaded mating surfaces, causing jamming and ultimately leading to the complete failure of the disassembly device. Furthermore, the threaded connection and clearance fit structure in this patent will experience increased clearance and seal failure due to thermal expansion and contraction under alternating high-temperature flue gas conditions, resulting in poor sealing stability under high-temperature conditions. Utility Model Content

[0004] The purpose of this invention is to provide a detection probe with a replaceable filter element, which enables rapid filter element replacement, improves maintenance efficiency, enhances sealing reliability, and strengthens equipment operation stability.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] A detection probe with a replaceable filter element includes a probe body and a filter element assembly detachably installed at the rear end of the probe body. The filter element assembly includes an integrated filter element base and a sintered filter element. The integrated filter element base is a coaxially machined stepped shaft structure. The integrated filter element base is provided with a filter body fixing section, a coaxial guide positioning section, a flange docking plate, and a gas path connection section sequentially arranged from front to back along the flow direction of the gas to be measured. The rear end face of the sintered filter element is fixedly connected to the filter body fixing section. The rear end opening of the filter body fixing section is fitted into the coaxial guide positioning section and forms a sealed rigid fixation. The coaxial guide positioning section is fixedly connected to the flange docking plate, and the flange docking plate is fixedly connected to the gas path connection section. The rear end face of the probe body is provided with a docking flange that is completely matched with the flange docking plate. The flange docking plate and the flange docking flange are detachably rigidly connected by fastening bolts.

[0007] Furthermore, the gas path connection section is coaxially and sealed with the sampling gas path leading to the detection sensor at the rear end of the probe body.

[0008] Furthermore, the integrated filter base has a through-hole inside, which connects the inner cavity of the sintered filter element with the sampling gas path of the probe body.

[0009] Furthermore, the through-hole is a straight-through channel with a constant diameter throughout.

[0010] Furthermore, the diameter of the through-hole is equal to the inner cavity diameter of the sintered filter element.

[0011] Furthermore, the sintered filter element is a blind-end cylindrical porous sintered metal structure, and the front end of the sintered filter element is a closed end face.

[0012] Furthermore, both the outer peripheral sidewall and the front closed end face of the sintered filter element are filtration working surfaces.

[0013] Furthermore, the flange has several sets of fixed through holes circumferentially connected to the disc, and the probe body's connecting flange has internal threaded holes that correspond one-to-one with the fixed through holes. The fastening bolts pass through the fixed through holes and are screwed into the internal threaded holes.

[0014] Furthermore, an annular sealing groove is provided between the mating end faces of the flange mating plate and the mating flange, and an elastic sealing ring is installed in the annular sealing groove.

[0015] Furthermore, an O-ring is provided between the filter body fixing section and the coaxial guide positioning section, and the O-ring is interference-fitted with the inner wall of the coaxial guide positioning section to form a radial seal.

[0016] The beneficial effects of this utility model are as follows:

[0017] This invention employs a coaxially machined stepped shaft integrated filter element base, integrating the core functions of filter body fixing, flange connection, and gas path connection onto a single base. This effectively eliminates the cumulative coaxiality tolerance caused by splicing multiple components, ensuring the full coaxiality of the filter element assembly and the probe body's sampling gas path. It avoids airflow disturbance and sampling data distortion caused by gas path misalignment, significantly reducing the risk of sealing failure and gas leakage under high temperature alternation and strong vibration conditions. At the same time, the nested sealing rigid fixing structure enhances the connection strength between the sintered filter element and the integrated filter element base, preventing connection loosening caused by operating vibration and improving the airtight reliability and structural rigidity of the device. The filter assembly is located at the rear end of the probe body and at the front end of the gas path leading to the detection sensor. After the gas to be measured is sampled by the probe body, it is filtered by the filter before entering the detection sensor, which protects the sensor from dust and corrosive components to the greatest extent and extends the service life of the detection components. At the same time, the filter assembly is located on the external non-insertion end of the probe body, so the filter can be replaced without removing the probe from the sampling pipeline, which reduces the difficulty of maintenance and equipment downtime. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 ;

[0019] Figure 2 This is a schematic diagram of the structure of the present invention. Figure 2 ;

[0020] Figure 3 This is a schematic diagram of the structure of the present invention without the probe body;

[0021] In the picture:

[0022] 1. Probe body; 2. Sintered filter element; 3. Filter body fixing section; 4. Coaxial guide positioning section; 5. Flange mating plate; 6. Gas path connection section; 7. Fixing through hole. Detailed Implementation

[0023] The present invention will now be described and illustrated in detail with reference to the embodiments.

[0024] Example 1

[0025] like Figure 1-3 As shown, the replaceable filter element detection probe includes a probe body 1 and a filter element assembly detachably installed at the rear end of the probe body 1. The filter element assembly includes an integrated filter element base and a sintered filter element 2. The integrated filter element base is a coaxially machined stepped shaft structure. The integrated filter element base is provided with a filter body fixing section 3, a coaxial guide positioning section 4, a flange docking plate 5, and a gas path connection section 6 sequentially from front to back along the flow direction of the gas being measured. The rear end face of the sintered filter element 2 is fixedly connected to the filter body fixing section 3. The rear end opening of the filter body fixing section 3 is fitted into the coaxial guide positioning section 4 and forms a sealed rigid fixation. The coaxial guide positioning section 4 is fixedly connected to the flange docking plate 5. The flange docking plate 5 is fixedly connected to the gas path connection section 6. The rear end face of the probe body 1 is provided with a docking flange that is completely matched with the flange docking plate 5. The flange docking plate 5 and the docking flange are detachably rigidly connected by fastening bolts.

[0026] The gas path connection section 6 is coaxially and sealed with the sampling gas path leading to the detection sensor at the rear end of the probe body 1.

[0027] The integrated filter base has a through hole inside, which connects the inner cavity of the sintered filter element 2 with the sampling gas path of the probe body 1.

[0028] The through-hole is a straight-through channel with a constant diameter throughout.

[0029] The diameter of the through-hole is equal to the inner cavity diameter of the sintered filter element 2.

[0030] The sintered filter element 2 is a blind-end cylindrical porous sintered metal structure, and the front end of the sintered filter element 2 is a closed end face.

[0031] The outer peripheral sidewall and the front closed end face of the sintered filter element 2 are both working surfaces for filtration.

[0032] The flange connecting plate 5 has several sets of fixed through holes 7 circumferentially. The connecting flange of the probe body 1 has internal thread holes that correspond one-to-one with the fixed through holes 7. The fastening bolts pass through the fixed through holes 7 and are screwed into the internal thread holes.

[0033] An annular sealing groove is provided between the flange mating plate 5 and the mating end face of the mating flange, and an elastic sealing ring is installed in the annular sealing groove.

[0034] An O-ring is provided between the filter body fixing section 3 and the coaxial guide positioning section 4. The O-ring is interference-fitted with the inner wall of the coaxial guide positioning section 4 to form a radial seal.

[0035] Working process and principle:

[0036] I. Normal Sampling and Testing Process

[0037] The industrial flue gas being tested first enters the internal sampling channel of the probe body 1, flows along the airflow direction to the detection sensor unit behind, and first comes into contact with the sintered filter element 2 of the filter element assembly; the sintered filter element 2 adopts a blind-end cylindrical porous sintered metal structure, and the outer peripheral sidewall and the front closed end face of the sintered filter element 2 are both filtering working surfaces, so the gas being tested can achieve uniform filtration of the entire circumference, reduce the accumulation rate of dust particles, avoid rapid clogging of the filter element, and extend the service life of the filter element.

[0038] After the gas being tested is filtered through the entire circumference of the sintered filter element 2, solid impurities such as dust, particulate matter, and tar are completely removed. The clean gas being tested then enters the inner cavity of the sintered filter element 2, preventing blockage of the subsequent sampling gas path and extending the service life of the core detection components.

[0039] The clean gas filtered by the sintered filter element 2 enters the through-hole inside the integrated filter element base. The through-hole is a straight channel with a uniform diameter throughout, and its diameter is completely consistent with the inner cavity diameter of the sintered filter element 2. The entire airflow channel has no diameter changes, no bends, no dead angles, and the measured airflow is stable without turbulence or pulsation, which can fully guarantee the representativeness of the sampled gas. The clean gas flows along the through-hole, passing sequentially through the filter body fixing section 3, the coaxial guide positioning section 4, the flange docking plate 5, and the gas path connection section 6 of the integrated filter element base. Finally, it enters the sampling gas path leading to the detection sensor at the rear end of the probe body 1 through the gas path connection section 6, and is sent to the detection and analysis unit to complete the accurate detection of gas parameters. The integrated filter element base is a stepped shaft structure that is coaxially machined in one piece, which can eliminate the cumulative coaxiality tolerance caused by the splicing of multiple parts, avoid airflow disturbance and sampling data distortion caused by gas path misalignment, and at the same time reduce the sealing points caused by the splicing of multiple parts, reducing the risk of gas leakage.

[0040] During normal sampling, the elastic sealing ring between the flange connecting plate 5 and the probe body 1 flange, and the O-ring between the filter body fixing section 3 and the coaxial guide positioning section 4 form a sealing structure to avoid the problem of data distortion caused by leakage of the measured gas and infiltration of outside air. It can still maintain stable airtight performance under harsh industrial conditions of high temperature alternation and strong vibration.

[0041] II. Filter element replacement and maintenance process

[0042] When the sintered filter element 2 becomes clogged or worn after long-term use and needs to be replaced or maintained, it is not necessary to remove the probe body 1 from the sampling pipeline. Simply unscrew the fastening bolts passing through the fixing hole 7 and release the rigid connection between the flange docking plate 5 and the rear flange docking plate of the probe body 1. The entire filter element assembly can then be removed from the rear of the probe body 1. The entire disassembly process does not require disassembling the shell of the probe body 1 or disconnecting the internal sampling gas path and electrical wiring. A single person can quickly complete the operation, improving maintenance efficiency and reducing the operational difficulty and safety risks of high-altitude pipeline operations.

[0043] When replacing the new filter assembly, first insert the sintered filter element 2 of the new filter assembly into the docking inner hole at the rear end of the probe body 1. This will achieve the pre-positioning of the radial and coaxiality of the filter assembly, eliminating the need for repeated manual alignment of the bolt holes and reducing installation difficulty. At the same time, it can ensure the precise coaxiality of the filter assembly and the sampling gas path of the probe body 1, avoiding airflow disturbance problems caused by misalignment during installation.

[0044] After the sintered filter element 2 is inserted into place, the flange mating plate 5 and the mating flange of the probe body 1 are completely fitted together. The fastening bolts are passed through the fixing through hole 7 on the flange mating plate 5, screwed into the corresponding internal thread hole of the mating flange and locked, thus completing the installation and fixing of the filter element assembly. The entire disassembly and assembly process does not require the sintered filter element 2 to be rotated circumferentially, avoiding the cracking and damage problems of brittle filter elements such as sintered metals due to uneven stress when disassembling and assembling existing threaded screwing structures.

[0045] After the filter assembly is installed, the device can resume normal sampling and testing. The entire filter replacement process is simple and quick, reducing the difficulty of maintenance and equipment downtime.

Claims

1. A detection probe with a replaceable filter element, comprising a probe body (1) and a filter element assembly detachably mounted at the rear end of the probe body (1), characterized in that, The filter assembly includes an integrated filter base and a sintered filter element (2); the integrated filter base is a stepped shaft structure machined coaxially. The integrated filter base is provided with a filter body fixing section (3), a coaxial guide positioning section (4), a flange docking plate (5) and a gas path connection section (6) in sequence from front to back along the flow direction of the gas being measured; the rear end face of the sintered filter element (2) is fixedly connected to the filter body fixing section (3), the rear end opening of the filter body fixing section (3) is fitted into the coaxial guide positioning section (4) and forms a sealed rigid fixation, the coaxial guide positioning section (4) is fixedly connected to the flange docking plate (5), and the flange docking plate (5) is fixedly connected to the gas path connection section (6); the rear end face of the probe body (1) is provided with a docking flange that is completely matched with the flange docking plate (5), and the flange docking plate (5) and the docking flange are detachably rigidly connected by fastening bolts.

2. The detection probe for the replaceable filter element according to claim 1, characterized in that, The gas path connection section (6) is coaxially and sealed with the sampling gas path leading to the detection sensor at the rear end of the probe body (1).

3. The detection probe for the replaceable filter element according to claim 2, characterized in that, The integrated filter base has a through hole inside, which connects the inner cavity of the sintered filter element (2) with the sampling gas path of the probe body (1).

4. The detection probe for the replaceable filter element according to claim 3, characterized in that, The through-hole is a straight-through channel with a constant diameter throughout.

5. The detection probe for the replaceable filter element according to claim 3, characterized in that, The diameter of the through-hole is equal to the inner cavity diameter of the sintered filter element (2).

6. The detection probe for the replaceable filter element according to claim 1, characterized in that, The sintered filter element (2) is a blind-end cylindrical porous sintered metal structure, and the front end of the sintered filter element (2) is a closed end face.

7. The detection probe for a replaceable filter element according to claim 6, characterized in that, The outer peripheral sidewall and the front closed end face of the sintered filter element (2) are both working surfaces for filtration.

8. The detection probe for the replaceable filter element according to claim 1, characterized in that, The flange connecting plate (5) has several sets of fixed through holes (7) in the circumference. The connecting flange of the probe body (1) has internal thread holes that correspond one-to-one with the fixed through holes (7). The fastening bolts pass through the fixed through holes (7) and are screwed into the internal thread holes.

9. The detection probe for a replaceable filter element according to claim 8, characterized in that, An annular sealing groove is provided between the flange mating plate (5) and the mating end face of the mating flange, and an elastic sealing ring is installed in the annular sealing groove.

10. The detection probe for the replaceable filter element according to claim 1, characterized in that, An O-ring is provided between the filter body fixing section (3) and the coaxial guide positioning section (4). The O-ring is interference-fitted with the inner wall of the coaxial guide positioning section (4) to form a radial seal.

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