Abrasion-proof treatment method for CEMS (Continuous Emission Monitoring System) sampling probe

Abstract

The invention relates to the technical field of anti-abrasion treatment, and particularly discloses an anti-abrasion treatment method for a CEMS sampling probe. The method comprises the following steps: accurately measuring geometric parameters and an erosive wear area of the probe rod; cleaning the to-be-protected surface of the probe rod; customizing an aluminum oxide outer sleeve; the sleeve is arranged outside the probe rod in a sleeving mode; the annular gap is filled with pre-compressed graphite rope filler, and tight filling is formed through mechanical dense adjustment; carrying out fixed inspection; high-temperature-resistant sealant is smeared at the two ends of the sleeve; and finally curing and mounting. The composition comprises an aluminum oxide outer sleeve, a graphite rope filler and a high-temperature-resistant sealant. According to the method, through the composite protection structure, the scouring resistance of the CEMS sampling probe in the high-temperature and high-dust flue gas environment is remarkably improved, and the method has the advantages that the operation process is clear, and construction is convenient and fast; the prepared wear-resistant structure can effectively prolong the service life of the probe rod by 4-5 times, greatly improve the operation stability of equipment and reduce the maintenance cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of anti-abrasion treatment, more particularly, it relates to a CEMS sampling probe anti-abrasion treatment method. BACKGROUND

[0002] The CEMS sampling probe probe rod is the core component for realizing continuous monitoring of pollutant concentration in the flue of the power plant denitration system. It needs to be installed in the boiler tail flue for a long time to continuously collect flue gas samples to ensure the accuracy and continuity of the monitoring data, and provide key data support for the environmental protection emission control of the power plant and the operation parameter adjustment of the denitration system, which is directly related to the environmental protection compliance and stable operation of the equipment of the power plant.

[0003] The current CEMS sampling probe probe rod of the power plant denitration is generally made of carbon steel, 304 stainless steel or 316 stainless steel. However, the inside of the boiler tail flue is in a high-temperature environment of about 350 DEG C for a long time, and the flue gas contains a lot of dust and has a high flow speed. The high-speed flowing dust will continuously and strongly erode the surface of the probe rod. The existing stainless steel or carbon steel probe rod cannot adapt to this harsh working condition. It will be worn out and fail after about one year of use, which not only causes the interruption of CEMS monitoring, affecting the continuity and accuracy of the pollutant emission data, but also needs to be frequently stopped and disassembled for replacement, greatly increasing the equipment maintenance cost and operation and maintenance workload. In addition, the worn-out probe rod may cause flue gas leakage, which poses a hidden danger to the safe and stable operation of the denitration system. SUMMARY

[0004] In order to solve the problem that the existing CEMS sampling probe probe rod has a short service life due to poor erosion resistance in a high-temperature and high-dust flue gas environment, the present application provides a CEMS sampling probe anti-abrasion treatment method.

[0005] A CEMS sampling probe anti-abrasion treatment method, comprising the following steps: S1, parameter measurement: measuring the geometric parameters of the existing CEMS sampling probe probe rod, including the outer diameter, the total length, and the specific position and range of the erosion and abrasion area, the erosion and abrasion area being the section of the probe rod that actually erodes in the flue; S2, surface cleaning: cleaning the surface of the probe rod to be protected to remove dirt and oxides on the surface; S3, sleeve customization: customizing an alumina outer sleeve according to the geometric parameters, the inner diameter of the alumina outer sleeve being 5-10 mm larger than the outer diameter of the probe rod, the wall thickness being 2-5 mm, and the length being 25-35 cm longer than the erosion and abrasion area; S4, sleeve assembly: sleeving the customized alumina outer sleeve on the outside of the probe rod, and making the alumina outer sleeve completely cover the erosion and abrasion area; S5, gap filling: filling graphite rope filler in the annular gap between the probe rod and the alumina sleeve, and adjusting the graphite rope filler in the annular gap to form a tight filling through mechanical compaction; S6, fixed inspection: applying an axial tension of 5-20N to the assembled alumina sleeve, and confirming the reliable fixation when no relative displacement occurs between the alumina sleeve and the probe rod; S7, end sealing: uniformly applying high-temperature resistant sealant on both ends of the alumina sleeve, and the temperature resistance of the high-temperature resistant sealant is not less than 500℃; S8, curing and installation: allowing the high-temperature resistant sealant to cure for 20-28h under natural conditions, and reinstalling the treated probe rod to the CEMS sampling probe after the curing is completed.

[0006] By adopting the above technical scheme, the geometric parameters of the probe rod and the position and range of the erosion and wear area are measured, which provides a precise size reference for customization of the alumina sleeve; the surface of the probe rod to be protected is cleaned, which removes surface dirt and oxides and avoids the influence of impurities on the subsequent assembly fit; the alumina sleeve of a specific size is customized according to the size, which utilizes the high hardness of the alumina material itself to form a physical protective barrier; the alumina sleeve is sleeved and completely covers the erosion and wear area, which precisely aligns the wear part and achieves targeted protection; the graphite rope filler is filled in the annular gap and mechanically compacted to fill the gap, fix the position of the sleeve, and buffer the vibration impact in the flue; the axial tension is applied to the alumina sleeve for inspection, which verifies the firmness of the connection between the sleeve and the probe rod; the high-temperature resistant sealant with a temperature resistance of not less than 500℃ is applied on both ends of the sleeve, which blocks the end gap and prevents dust from entering from the gap; the high-temperature resistant sealant is cured for a sufficient time under natural conditions, which ensures the stability of the sealant formation and maintains long-term sealing effect, thereby achieving the corresponding wear-resistant treatment effect.

[0007] Preferably, in step S1, the precise measurement of the geometric parameters is performed by using a caliper or a laser measuring instrument, and the erosion and wear area is determined by measuring the starting position and the ending position of the wear trace.

[0008] By using the above technical scheme, the geometric parameters are accurately measured by using a caliper or a laser measuring instrument, which plays a role in ensuring the accuracy of the outer diameter and total length data of the probe rod, avoids the problem of mismatching of the inner diameter and length of the subsequently customized alumina outer sleeve due to size measurement deviation, and ensures the assembly adaptability of the sleeve and the probe rod; the scouring wear area is determined by measuring the starting position and the ending position of the wear trace, which plays a role in accurately defining the specific section range of the probe rod that needs to be protected, avoids the formation of a protection blind area due to insufficient coverage of the subsequent alumina outer sleeve due to ambiguous positioning of the scouring wear area, or causes waste of materials and protection resources due to excessive coverage, and further ensures the protection pertinence and assembly rationality.

[0009] Preferably, in step S3, the material of the alumina outer sleeve is high-purity alumina with an alumina mass content of 95% or more.

[0010] By using the above technical scheme, by selecting high-purity alumina with an alumina mass content of 95% or more as the material of the alumina outer sleeve, the high-purity alumina has better hardness and high-temperature wear resistance than low-purity alumina, which plays a role in strengthening the physical structure strength and scouring resistance of the sleeve. The impurity content in high-purity alumina is lower, which can reduce the weakening of the overall wear resistance of the material by impurities, ensure that the sleeve is not prone to surface wear, cracking and other problems when long-term subjected to high-speed dust scouring in a high-temperature and high-dust flue environment, avoid premature failure of the sleeve due to insufficient material purity, further ensure the long-term stability of the outer protective barrier, and also provide a reliable structural basis for subsequent assembly with the probe rod, ensuring the effective realization of the protection function.

[0011] Preferably, in step S5, the diameter of the graphite rope filler is 3-8mm, and the graphite rope filler is pre-compressed before being filled, and the pre-compression treatment compresses it to 50-70% of the original diameter.

[0012] By adopting the above technical scheme, by selecting the graphite rope filler with a diameter of 3-8 mm, and combining the annular gap size of 5-10 mm between the alumina outer sleeve and the probe rod in step S3, the size of the gap space is adapted, the problems of residual gap after filling due to too small diameter of the graphite rope or difficult to fill into the gap due to too large diameter of the graphite rope are avoided, and it is ensured that the graphite rope can initially cover the gap range; by pre-compressing the graphite rope filler to 50-70% of the original diameter before filling, the density of the graphite rope is increased and the volume is contracted, after filling into the annular gap, the compressed graphite rope can tightly fit the outer wall of the probe rod and the inner wall of the alumina outer sleeve by the elastic rebound of itself, which not only avoids the displacement of the sleeve in the flue vibration due to the loose space in the gap, but also enhances the buffering capacity of vibration impact through the compact structure after compression, reduces the channel for dust infiltration from the gap, and further ensures the sealing performance of the gap filling and the stability of the sleeve fixing.

[0013] Preferably, the pre-compression treatment is realized by making the graphite rope filler pass through a pair of spacing-adjustable rollers or by radial extrusion using a clamp.

[0014] By adopting the above technical scheme, the graphite rope filler is pre-compressed by passing through a pair of spacing-adjustable rollers, and the spacing between the rollers can be flexibly adjusted according to the target compression ratio of the graphite rope, which realizes continuous and uniform extrusion of the graphite rope, avoids the problems of local compression force imbalance and inconsistent compression degree caused by manual compression, ensures uniform density of the graphite rope as a whole, and enables the graphite rope to stably maintain the preset size after compression; the pre-compression is realized by radial extrusion of the graphite rope using a clamp, which takes advantage of the feature that the clamp can apply directional and controllable radial pressure, realizes accurate control of the compression degree of the graphite rope of different lengths or sections, is especially suitable for scenarios where local compaction is required, and can also ensure that the graphite rope reaches the preset compression ratio, and both pre-compression methods can provide a reliable premise for the graphite rope to tightly fit the outer wall of the probe rod and the inner wall of the alumina outer sleeve after filling into the annular gap, avoid the problem of inconsistent rebound of the graphite rope due to uneven compression, further consolidate the tightness of the gap filling and the stability of the sleeve fixing.

[0015] Preferably, in step S7, the high-temperature-resistant sealant is a silicone sealant.

[0016] By adopting the above technical scheme, the organic silicon sealant can rely on the high-temperature-resistant nature of the organic silicon material to maintain the sealing structure without failure and cracking at a flue high temperature of not less than 500 DEG C, play a role in continuously plugging the gap between the two ends of the alumina outer sleeve, completely prevent dust from invading the annular space between the probe rod and the sleeve through the end gap, further improve the sealing performance of the overall protection structure, and provide end sealing protection for long-term stability of the anti-abrasion effect. The organic silicon sealant in the present application is purchased from Fosman Technology (Beijing) Co., Ltd., and the article number is 9502053.

[0017] Preferably, in step S3, the outer surface of the alumina outer sleeve is subjected to surface roughening treatment during customization.

[0018] By adopting the above technical scheme, the surface of the alumina outer sleeve is subjected to surface roughening treatment to form a rough surface morphology, which plays a role in dispersing the impact force of high-speed dust in the flue. Compared with a smooth surface, the roughened surface can change the impact trajectory of dust particles, avoid the concentration of dust on a fixed area of the sleeve surface, and reduce the rapid wear caused by continuous local erosion. At the same time, the rough surface can also slightly change the flow state of high-speed airflow on the outer surface of the sleeve, reduce the direct friction intensity between the airflow and the sleeve surface, and further reduce the damage caused by airflow friction to the sleeve surface. This treatment method can enhance the adaptability of the alumina outer sleeve to the erosion environment by optimizing the surface morphology while maintaining the high hardness of the alumina outer sleeve, avoid the rapid decline of the protection ability caused by the single surface structure, and thus more durably maintain the integrity of the outer physical protection barrier to provide stable anti-abrasion protection for the probe rod.

[0019] Preferably, the surface roughening treatment adopts sandblasting treatment with 20-60 mesh sand particles, and the sandblasting treatment forms a roughened surface with a roughness of Ra3.2 μm to Ra12.5 μm on the outer surface of the alumina outer sleeve.

[0020] By adopting the above technical scheme, the sand blasting treatment is performed by using 20-60 mesh sand particles, and the adaptability of the particle size of the sand particles in the range is utilized. The 20 mesh sand particles can form a relatively deep and wide surface indentation, and the 60 mesh sand particles can create fine and uniform rough texture, thereby playing a role in flexibly regulating the roughening degree according to the actual protection requirements of the alumina outer sleeve, avoiding excessive damage to the surface caused by too coarse sand particles, affecting the structural strength of the sleeve, or being unable to form effective roughening texture due to too fine sand particles. By controlling the sand blasting treatment to form a roughened surface with a roughness of Ra3.2 μm to Ra12.5 μm on the outer surface of the alumina outer sleeve, the roughness range can ensure that the surface has sufficient concave-convex morphology to disperse the impact force of high-speed dust and change the friction trajectory of the airflow, and can avoid problems caused by roughness exceeding the range, such as easy dust adhesion and accumulation due to too large roughness, and aggravation of local wear, or roughening treatment losing the actual significance of dispersing impact due to too small roughness. The combination of the two parameters can ensure that the surface roughening effect matches the material properties of the alumina outer sleeve and the flue gas scouring environment, so that the roughening treatment can effectively assist the outer sleeve in enhancing the anti-scouring ability and more durably maintaining the outer protection function.

[0021] Preferably, in step S8, the curing is performed at room temperature or accelerated curing is performed by heating, wherein the heating temperature is not more than 100°C and the heating time is not more than 5h.

[0022] By adopting the above technical scheme, by performing curing at room temperature, it is not necessary to additionally configure a heating device, thereby playing a role in simplifying the on-site construction process and reducing the operation complexity, and at the same time, avoiding the heat deformation of the probe rod base material or the alumina outer sleeve caused by external heating, thereby ensuring that the high-temperature resistant sealant slowly and stably completes the curing and forming under natural conditions, maintaining the structural integrity and long-term high-temperature resistant sealing performance of the sealant itself. By adopting accelerated curing by heating and strictly controlling the heating temperature to be not more than 100°C and the heating time to be not more than 5h, the internal chemical reaction rate of the sealant can be accelerated by moderate heating, thereby playing a role in shortening the curing period and adapting to the rapid completion requirement in an emergency installation scene, and at the same time, avoiding the cracking, aging or sealing performance attenuation of the sealant caused by too high heating temperature, and preventing the adverse effects of too long heating time on the connection stability of the probe rod and the sleeve, thereby ensuring that the sealant still has good adhesion strength and high-temperature resistant sealing performance after accelerated curing.

[0023] Preferably, in step S5, the graphite rope filler is filled in the axial direction of the annular gap in sections, and mechanical compaction is realized by section-by-section knocking.

[0024] By adopting the technical scheme, the graphite rope filler is filled in segments along the axial direction of the annular gap, combined with the structural characteristics that the annular gap extends along the axial direction, the effects of avoiding the accumulation deviation, local vacancy or uneven distribution of the graphite rope in the gap when filled in one body at a time are achieved, the graphite rope can uniformly cover the entire axial length of the annular gap, a regular filling basis is provided for the subsequent dense processing of each segment, and the loose space formed due to the uneven axial filling and the gap not being covered in some areas is prevented; the graphite rope filled in segments is knocked segment by segment to realize mechanical densification, by means of the directional external force generated by knocking, the effects of extruding and eliminating the small gaps inside each segment of the graphite rope and improving the filling density of the graphite rope are achieved, the displacement or the decrease of the compaction degree of the graphite rope due to the loose gaps inside a single segment and the influence of subsequent vibration are avoided, and the compaction degree of each segment in the axial direction of the annular gap is consistent, the local compaction deficiency caused by uneven transmission of the overall knocking force is avoided, and the graphite rope can be more closely attached to the outer wall of the probe rod and the inner wall of the alumina outer sleeve tube, the effects of fixing the sleeve tube, buffering vibration and blocking the penetration of dust are achieved, and the reliability of the gap filling is further ensured.

[0025] In summary, the present application has the following beneficial effects: 1. Since the present application adopts the composite protection structure of adding an alumina outer sleeve tube to the probe rod and filling graphite rope filler in the annular gap, the alumina material itself has extremely high hardness and wear resistance and can directly resist the erosion of high-speed dust in the flue, the graphite rope filling layer not only plays a role in fixing the sleeve tube but also effectively buffers vibration, and the end part is effectively sealed by the high-temperature resistant sealant, the service life of the CEMS sampling probe in the high-temperature and high-dust flue gas environment is significantly prolonged, and the maintenance frequency caused by wear failure is greatly reduced.

[0026] 2. In the present application, the graphite rope filler is preferably pre-compressed to a specific range, since the pre-compression treatment enables the graphite rope to generate sufficient rebound stress after being filled in the annular gap, thereby forming a tight filling state, and combined with the operation mode of filling in segments along the axial direction and knocking in segments, the effects of ensuring uniform filling without gaps and effectively preventing the alumina outer sleeve tube from loosening in the long-term vibration environment are achieved.

[0027] 3. The method of the present application performs sand blasting roughening treatment on the outer surface of the alumina outer sleeve tube with specific parameters and selects an organic silicone sealant with qualified temperature resistance, since the roughened surface significantly increases the contact area and mechanical biting effect of the sealant, and the selected sealant can maintain an elastic sealing state at high temperature, the effects of maintaining durable and effective sealing even under thermal cycling conditions and preventing abrasives from invading and wearing the probe rod from the end part are achieved. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a flow chart of a CEMS sampling probe anti-abrasion treatment method provided by the present application. DETAILED DESCRIPTION

[0029] The present application is further described in detail below in combination with examples and comparative examples.

[0030] Technical ideas: In the related art, the CEMS sampling probe rod is made of carbon steel, 304 stainless steel or 316 stainless steel, etc. conventional metal materials. Under the typical working conditions of high temperature, high dust content and high speed airflow of about 350℃ in the tail flue of the power plant, there are problems of insufficient erosion resistance and long-term structural stability. The core reason is that the hardness of the conventional metal material is limited, which is difficult to resist the continuous impact of high-speed dust, and long-term use is easy to appear surface wear, pipe wall thinning and even wear and tear. At the same time, the existing technology does not design a targeted protection structure for the wear area of the probe rod, lacks an effective outer physical barrier, and does not consider the key details such as gap filling and end sealing between the protection component and the probe rod, which makes the dust easy to invade from the gap, and the vibration easy to cause the displacement of the protection component, further aggravating the wear of the probe rod, ultimately shortening the service life of the probe rod and frequent maintenance and replacement, affecting the continuity of CEMS monitoring and equipment operation stability.

[0031] The present technical solution aims at the above problems, and a complete protection system is constructed through specific technical means of multi-link cooperation to solve the problems: first, the geometric parameters such as the outer diameter and the total length of the probe rod are accurately measured by a caliper or a laser measuring instrument, and the erosion wear area is determined by the start and end positions of the wear traces, which provides accurate size basis for subsequent protection component customization; then, a high-purity alumina sleeve with an alumina mass content of more than 95% is customized according to the size, and an outer physical protection barrier is formed by using the high hardness characteristics of alumina to accurately cover the wear area; then, a graphite rope with a diameter of 3-8mm is filled in the annular gap between the probe rod and the sleeve, which not only fills the gap and fixes the position of the sleeve, but also can buffer the vibration impact of the flue; finally, silicone sealant with a temperature resistance of not less than 500℃ is applied at both ends of the sleeve, which is cured by room temperature or heating of not more than 100℃, and the fixation reliability of the sleeve and the probe rod is verified by applying an axial tension of 5-20N, from material selection, structure adaptation, gap filling, sealing and curing to fixation verification, which comprehensively solves the problems of probe rod wear caused by insufficient erosion resistance of material, incomplete protection and missing details in the prior art.

[0032] Preparation Example 1 The preparation method of the high-purity alumina sleeve is as follows: Take 1200g of high-purity alumina powder, add 48g of polyvinyl alcohol and 210mL of deionized water, and put the three together with 3600g of alumina grinding balls with a diameter of 8mm into a 5L planetary ball mill ceramic grinding tank. Grind continuously at a speed of 250r / min for 1.5h, with stirring every 30min during the process. A uniform and fine alumina slurry is obtained. Select a stainless steel mold with a smooth inner wall, evenly apply medical Vaseline to the inner wall of the mold, slowly pour the ground alumina slurry into the mold, and use a glass rod to vibrate the outer wall of the mold to remove air bubbles. Cover the end cap of the mold and place it in a hydraulic extrusion machine. Apply an axial pressure of 0.8MPa and maintain for 12min to shape the slurry into a tubular blank.

[0033] Take the shaped tubular blank out of the mold and put it into an electric heating air drying oven. First, dry at 85℃ with a wind speed of 1.5m / s for 8h, then reduce to 70℃ and continue drying for 16h. During the process, weigh the blank every 4h until the weight difference of two consecutive weighings is not more than 0.5g. Place the dried tubular blank into a high-temperature box-type sintering furnace, with a spacing of 5cm between the blanks. Close the door and increase the temperature to 600℃ at a rate of 5℃ / min and maintain for 1h. Then increase the temperature to 1620℃ at the same rate and maintain for 5h. Then decrease the temperature to 800℃ at a rate of 3℃ / min, and then cool naturally with the furnace to room temperature. After removal, polish the two end cuts with 120 mesh sandpaper to remove burrs, and then blow off the dust on the inner and outer surfaces of the tube with compressed air at 0.4MPa. This is the substrate for subsequent processing.

[0034] Example 1 The embodiment of the present application provides a CEMS sampling probe wear-resistant treatment method, comprising the following steps: S1, parameter measurement: measure the geometric parameters of the existing CEMS sampling probe rod, including the outer diameter, the total length and the specific position and range of the erosion wear area, the erosion wear area being the section of the probe rod that actually wears in the flue; Wherein, the accurate measurement of geometric parameters is carried out by using a caliper or a laser measuring instrument, and the erosion wear area is determined by measuring the starting position and the ending position of the wear trace.

[0035] S2, surface cleaning: clean the surface of the probe rod to be protected to remove dirt and oxides on the surface; S3, sleeve customization: customize an alumina outer sleeve according to the geometric parameters, the inner diameter of the alumina outer sleeve being 7.5mm larger than the outer diameter of the probe rod, the wall thickness being 3.5mm, and the length being 30cm longer than the erosion wear area; Wherein, the material of the alumina outer sleeve is high-purity alumina, and the mass content of alumina is more than 95%; Wherein, the outer surface of the alumina outer sleeve is subjected to surface roughening treatment during customization; The surface roughening treatment adopts sand blasting treatment with 40-mesh sand particles, and the sand blasting treatment forms a roughened surface with a roughness of Ra 7.85 μm on the outer surface of the alumina outer sleeve.

[0036] S4, sleeve assembly: the customized alumina outer sleeve is sleeved on the outside of the probe rod, and the alumina outer sleeve completely covers the erosion wear area; S5, gap filling: filling the graphite rope filler in the annular gap between the probe rod and the alumina outer sleeve, and adjusting the mechanical compaction to form a tight filling of the graphite rope filler in the annular gap; The diameter of the graphite rope filler is 5.5 mm, and the graphite rope filler is pre-compressed before filling to 60% of the original diameter. The pre-compression is achieved by passing the graphite rope filler through a pair of spacing-adjustable rollers or by radial extrusion using a clamp. The graphite rope filler is filled in segments along the axial direction of the annular gap, and the mechanical compaction is achieved by segmental knocking.

[0037] S6, fixed inspection: applying an axial tension of 12.5 N to the assembled alumina outer sleeve, and confirming the reliable fixation when there is no relative displacement between the alumina outer sleeve and the probe rod. S7, end sealing: uniformly applying high-temperature resistant sealant on both ends of the alumina outer sleeve, and the temperature resistance of the high-temperature resistant sealant is not less than 500℃. The high-temperature resistant sealant is silicone sealant.

[0038] S8, curing installation: allowing the high-temperature resistant sealant to cure for 24 h under natural conditions, and reinstalling the treated probe rod to the CEMS sampling probe after curing. The curing is carried out at room temperature.

[0039] Example 2 The application provides a CEMS sampling probe wear-resistant treatment method, which comprises the following steps: S1, parameter measurement: measuring the geometric parameters of the existing CEMS sampling probe rod, including the outer diameter, the total length, and the specific position and range of the erosion wear area, the erosion wear area being the section of the probe rod actually worn in the flue; The accurate measurement of the geometric parameters is carried out by using a caliper or a laser measuring instrument, and the erosion wear area is determined by measuring the starting position and the ending position of the wear trace.

[0040] S2, surface cleaning: cleaning the surface to be protected of the probe rod to remove dirt and oxides on the surface; S3, sleeve customization: customizing an alumina outer sleeve according to geometric parameters, the inner diameter of the alumina outer sleeve is 5mm larger than the outer diameter of the probe rod, the wall thickness is 2mm, and the length is 25cm longer than the erosion wear area; wherein the material of the alumina outer sleeve is high-purity alumina, and the mass content of alumina is more than 95%; wherein the outer surface of the alumina outer sleeve is subjected to surface roughening treatment during customization; wherein the surface roughening treatment adopts sand blasting treatment with 20-mesh sand particles, and the sand blasting treatment forms a roughened surface with a roughness of Ra3.2μm on the outer surface of the alumina outer sleeve.

[0041] S4, sleeve assembly: the customized alumina outer sleeve is sleeved on the outside of the probe rod, and the alumina outer sleeve completely covers the erosion wear area; S5, gap filling: filling graphite rope fillers in the annular gap between the probe rod and the alumina outer sleeve, and adjusting the graphite rope fillers to form tight filling in the annular gap by mechanical compaction; wherein the diameter of the graphite rope filler is 3mm, and the graphite rope filler is subjected to pre-compression treatment before being filled, and the pre-compression treatment compresses it to 50% of the original diameter; wherein the pre-compression treatment is realized by making the graphite rope filler pass through a pair of spacing-adjustable rollers or by radial extrusion using a clamp; wherein the graphite rope fillers are filled in segments along the axial direction of the annular gap, and the mechanical compaction is realized by segment-by-segment knocking.

[0042] S6, fixed inspection: applying an axial tension of 5N to the assembled alumina outer sleeve, and confirming that the fixation is reliable when there is no relative displacement between the alumina outer sleeve and the probe rod; S7, end sealing: uniformly applying high-temperature resistant sealant to both ends of the alumina outer sleeve, and the temperature resistance of the high-temperature resistant sealant is not less than 500℃; wherein the high-temperature resistant sealant is a silicone sealant.

[0043] S8, curing installation: allowing the high-temperature resistant sealant to cure for 20h under natural conditions, and reinstalling the treated probe rod to the CEMS sampling probe after curing is completed; wherein the curing is accelerated by heating, and the heating temperature is not more than 100℃ and the heating time is not more than 5h.

[0044] Example 3 The application embodiment provides a CEMS sampling probe wear-resistant treatment method, which comprises the following steps: S1, parameter measurement: measure the geometric parameters of the existing CEMS sampling probe rod, including the outer diameter, the total length, and the specific location and range of the erosion wear area, which is the section of the probe rod that actually wears in the flue; Wherein, the accurate measurement of geometric parameters is carried out by using a caliper or a laser measuring instrument, and the erosion wear area is determined by measuring the starting position and the ending position of the wear trace.

[0045] S2, surface cleaning: clean the surface to be protected of the probe rod to remove dirt and oxides on the surface thereof; S3, sleeve customization: customize an alumina outer sleeve according to the geometric parameters, the inner diameter of the alumina outer sleeve being 10 mm larger than the outer diameter of the probe rod, the wall thickness being 5 mm, and the length being 35 cm longer than the erosion wear area; Wherein, the material of the alumina outer sleeve is high-purity alumina, and the alumina content is more than 95%; Wherein, the outer surface of the alumina outer sleeve is subjected to surface roughening treatment during customization; Wherein, the surface roughening treatment adopts sandblasting treatment with 60-mesh sand particles, and the sandblasting treatment forms a roughened surface with a roughness of Ra12.5 μm on the outer surface of the alumina outer sleeve.

[0046] S4, sleeve assembly: the customized alumina outer sleeve is sleeved on the outside of the probe rod, and the alumina outer sleeve completely covers the erosion wear area; S5, gap filling: fill the annular gap between the probe rod and the alumina outer sleeve with graphite rope fillers, and adjust the mechanical compaction to form a tight filling of the graphite rope fillers in the annular gap; Wherein, the diameter of the graphite rope filler is 8 mm, and the graphite rope filler is subjected to pre-compression treatment before being filled, which compresses it to 70% of the original diameter; Wherein, the pre-compression treatment is realized by making the graphite rope filler pass through a pair of spacing-adjustable rollers or by radial extrusion using a clamp; Wherein, the graphite rope fillers are filled in segments along the axial direction of the annular gap, and the mechanical compaction is realized by segment-by-segment knocking.

[0047] S6, fixation verification: an axial tension of 20 N is applied to the assembled alumina outer sleeve, and when no relative displacement occurs between the alumina outer sleeve and the probe rod, it is confirmed that the fixation is reliable; S7, end sealing: uniformly apply high-temperature resistant sealant to both ends of the alumina outer sleeve, and the temperature resistance of the high-temperature resistant sealant is not less than 500℃; Wherein, the high-temperature resistant sealant is a silicone sealant.

[0048] S8, curing installation: make the high-temperature resistant sealant cure for 28 hours under natural conditions, and after curing is completed, the treated probe rod is reinstalled to the CEMS sampling probe; wherein the curing is carried out at room temperature.

[0049] Comparative Example 1 The difference from Example 1 is only that the alumina outer sleeve is omitted, and the high-temperature resistant sealant is directly applied on the surface of the probe rod for protection.

[0050] Comparative Example 2 The difference from Example 1 is only that the alumina outer sleeve is replaced by a 304 stainless steel outer sleeve, and the size parameters are exactly the same as those of Example 1.

[0051] Comparative Example 3 The difference from Example 1 is only that the graphite rope filler is replaced by a common asbestos rope filler, and no pre-compression treatment is performed.

[0052] Comparative Example 4 The difference from Example 1 is only that the silicone sealant is replaced by a common epoxy resin sealant.

[0053] Comparative Example 5 The difference from Example 1 is only that the pre-compression treatment step of the graphite rope filler is cancelled, and the graphite rope filler is directly filled into the annular gap in the original diameter state.

[0054] I. Erosion resistance test The experiment uses a circulating high-temperature gas flow erosion test bench, which can accurately control the gas flow temperature, wind speed and abrasive concentration. The abrasive used is quartz sand with a particle size of 0.3 mm, and the test parameters are set as follows: gas flow temperature 350℃, wind speed 18m / s, and quartz sand concentration 200g / m³.

[0055] Three treated probe rods of Examples 1-3 and Comparative Examples 1-5 are selected as samples. The initial weight of each sample is measured using an electronic balance, and the initial wall thickness is recorded by uniformly selecting three measurement points in the erosion wear area using an ultrasonic thickness gauge. All samples are fixed on the sample holder of the test bench according to the actual flue installation angle, ensuring that the gas flow acts vertically on the preset erosion area. The test bench is started for continuous erosion for 1000 hours. During the test, the appearance of the samples is observed every 200 hours, and whether the alumina sleeve is damaged and whether the abrasive penetrates the sealing part is recorded. After the test is completed, the residual abrasive on the surface of the samples is cleaned, and the weight and wall thickness are measured again. The weight loss rate and the average wall thickness reduction of each sample are calculated, and the evaluation standard for better erosion resistance is that the weight loss rate is lower and the average wall thickness reduction is smaller.

[0056] wherein, ; .

[0057] II. High-temperature working condition structural stability test The experiment uses a programmable high-temperature constant-temperature oven, a micrometer, and a gas tightness testing device. Three treated probe rods of each of Examples 1-3 and Comparative Examples 1-5 are selected as samples. First, at room temperature, the micrometer is used to take four evenly distributed measurement points at each end of the alumina sleeve of each sample, and the initial relative position of the sleeve and the probe rod is recorded. Then, 0.05 MPa compressed air is introduced into the probe rod, the ends are sealed, the initial pressure is recorded, the pressure change is measured after standing for 1 hour, and the initial gas tightness pressure loss rate is calculated.

[0058] Subsequently, all samples are placed in a high-temperature constant-temperature oven, set to a temperature of 350°C, and kept at a constant temperature for 500 hours. Every 100 hours, the samples are taken out, cooled to room temperature, and the relative displacement of the sleeve and the gas tightness pressure loss rate are measured again. At the same time, it is observed whether the graphite rope appears loose, powders, or falls off. The evaluation criteria for structural stability are that the relative displacement of the sleeve is ≤0.1 mm, the gas tightness pressure loss rate is ≤5%, and the graphite rope has no obvious aging damage. Through data comparison, the deformation retention capability of the pre-compressed graphite rope at high temperature and the sealing durability of the high-temperature resistant sealant compared to ordinary epoxy resin sealant can be verified. If the structure is unstable, it will cause the abrasive to directly scour the probe rod, thereby weakening the resistance to scouring performance. Therefore, the experimental results are related to the resistance to scouring performance test, and together support the overall effectiveness of the scheme;

[0059] wherein, .

[0060] III. Long-term service life simulation test The experiment uses a comprehensive working condition simulation test bench. This equipment can realize temperature cycling, dust-containing airflow scouring, and real-time wall thickness monitoring. The temperature cycling is as follows: 350°C constant temperature for 8 hours and room temperature for 2 hours for one cycle, simulating the start and stop of the boiler and load changes. The parameters of the dust-containing airflow scouring are the same as those of the resistance to scouring test: wind speed 18 m / s, quartz sand concentration 200 g / m³.

[0061] Two treated probe rods of each of Examples 1-3 and Comparative Examples 1-5 are selected as samples. Three fixed monitoring points are marked on each sample in the scouring area. After recording the initial wall thickness with an ultrasonic thickness gauge, the sample is fixed in the test bench according to the actual installation method. Start the test bench to begin the cycle test. After completing 100 cycles, stop the machine and cool it to room temperature. Measure the wall thickness of each monitoring point and observe the sample state. When the wall thickness reduction of any monitoring point of any sample reaches 10% of the initial wall thickness or a penetrating wear occurs, stop the test of the sample and record the cumulative test time. If the cumulative test time of the sample exceeds 5000 hours and still does not reach the critical state, it is recorded as ≥5000 hours.

[0062] The results of the key performance test of examples 1-3 and comparative examples 1-5 are shown in Table 1.

[0063] Table 1:

[0064] As can be seen from examples 1-3 and comparative example 1 in combination with Table 1, examples 1-3 all rely on the alumina outer sleeve to form the first protective barrier against the direct scouring of the high-temperature dust-containing gas flow on the probe rod, while comparative example 1 omits the sleeve, and only the high-temperature resistant sealant cannot achieve long-term effective protection against wear and tear, the sealant is directly exposed to the high-speed airflow and the abrasive, and is easy to be scoured and damaged, resulting in the probe rod losing the outer shielding and directly bearing the impact of the abrasive, and at the same time, the sealing of the overall structure is damaged, making the airflow and the abrasive more easily invade, thereby affecting the scouring resistance and long-term use stability of the probe rod, highlighting the core role of the alumina outer sleeve in physically blocking the abrasive and maintaining the structural integrity.

[0065] As can be seen from examples 1-3 and comparative example 2 in combination with Table 1, the high-purity alumina material selected in examples 1-3 has better high-temperature wear resistance and structural stability, and can maintain its form and protection ability in a long-term high-temperature scouring environment; while comparative example 2 replaces it with a 304 stainless steel outer sleeve, since the wear resistance and high-temperature deformation resistance of stainless steel are weaker than those of alumina, under the continuous scouring of high-temperature dust-containing gas flow, the sleeve is more prone to wear and tear and relative displacement, and at the same time, the stability of the sealing part will also be affected by the deformation of the sleeve and decrease, resulting in the abrasive more easily invading the gap and indirectly weakening the protection effect on the probe rod, which shows that the scouring resistance and high-temperature stability of the outer sleeve material are important factors to ensure the effectiveness of the overall scheme.

[0066] As can be seen from examples 1-3 and comparative example 3 in combination with Table 1, the pre-compressed graphite rope used in examples 1-3 can not only maintain structural stability due to its excellent high-temperature resistance, but also tightly fill the gap between the probe rod and the sleeve through the pre-compression process to form reliable support and sealing; while comparative example 3 replaces it with an ordinary asbestos rope without pre-compression treatment, the high-temperature structure maintaining ability of the asbestos rope is weak, and the gap is not tightly filled due to the lack of pre-compression, which is easy to powder and fall off in a long-term high-temperature environment, causing the gap between the sleeve and the probe rod to increase, leading to problems such as relative displacement of the sleeve, decrease in air tightness, and the abrasive more easily scouring the probe rod through the gap, which further verifies the synergistic effect of the pre-compressed graphite rope in filling the gap, maintaining structural stability, and preventing the invasion of the abrasive.

[0067] It can be seen from Examples 1-3 and Comparative Example 4 in combination with Table 1 that the condensation type silicone sealant with a temperature resistance of not less than 500 DEG C selected in Examples 1-3 can maintain good sealing performance and structural integrity in a long-term high-temperature environment of 350 DEG C, effectively preventing the abrasives from invading the gap from the end of the sleeve; and after the ordinary epoxy resin sealant is replaced by Comparative Example 4, the epoxy resin is prone to cracking and aging due to insufficient temperature resistance under long-term high-temperature action, resulting in end sealing failure, significant decrease in air tightness, and abrasives entering the gap from the end, which damages the stable connection between the sleeve and the probe rod, and further affects the erosion resistance of the probe rod, indicating that the high-temperature resistant sealant is a key link to ensure end sealing and prevent abrasives from invading.

[0068] It can be seen from Examples 1-3 and Comparative Example 5 in combination with Table 1 that the graphite rope in Examples 1-3 is tightly attached to the gap between the probe rod and the sleeve through pre-compression treatment, forming a stable filling structure that is not prone to looseness under high-temperature environment; and after the pre-compression treatment is cancelled in Comparative Example 5, the graphite rope is not tightly filled in the gap, and is prone to looseness under high-temperature, which increases the relative displacement between the sleeve and the probe rod, decreases the air tightness, and makes the abrasives more easily contact the surface of the probe rod through the gap that is not tightly filled, which weakens the erosion resistance of the probe rod, indicating that the pre-compression process can improve the tightness of the graphite rope filling, strengthen the support of the graphite rope to the sleeve and the sealing of the graphite rope to the gap, and further synergistically ensure the overall protection effect.

[0069] The specific embodiments are merely illustrative of the present application, and are not intended to limit the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, and the modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method of wear prevention for a CEMS sampling probe, characterized by: The method comprises the following steps: S1, parameter measurement: measuring the geometric parameters of the existing CEMS sampling probe rod, including the outer diameter, the total length, and the specific location and range of the erosion wear area, which is the section of the probe rod that actually wears in the flue; S2, surface cleaning: cleaning the surface of the probe rod to be protected to remove dirt and oxides on the surface; S3, sleeve customization: customizing an alumina outer sleeve according to the geometric parameters, the inner diameter of the alumina outer sleeve being 5-10 mm larger than the outer diameter of the probe rod, the wall thickness being 2-5 mm, and the length being 25-35 cm longer than the erosion wear area; S4, sleeve assembly: fitting the customized alumina outer sleeve on the outside of the probe rod, and making the alumina outer sleeve completely cover the erosion wear area; S5, gap filling: filling graphite rope fillers in the annular gap between the probe rod and the alumina outer sleeve, and adjusting the mechanical compaction to make the graphite rope fillers form a tight filling in the annular gap; S6, fixation inspection: applying an axial tension of 5-20 N to the assembled alumina outer sleeve, and confirming the reliable fixation when there is no relative displacement between the alumina outer sleeve and the probe rod; S7, end sealing: uniformly applying high-temperature resistant sealant on both ends of the alumina outer sleeve, the temperature resistance of the high-temperature resistant sealant being not less than 500℃; S8, curing and installation: allowing the high-temperature resistant sealant to cure for 20-28 h under natural conditions, and reinstalling the treated probe rod to the CEMS sampling probe after the curing is completed.

2. The method of claim 1, wherein: In step S1, the precise measurement of the geometric parameters is performed by using a caliper or a laser measuring instrument, and the erosion wear area is determined by measuring the starting position and the ending position of the wear trace.

3. The method of claim 1, wherein: In step S3, the material of the alumina outer sleeve is high-purity alumina, and the mass content of alumina is more than 95%. In step S5, the diameter of the graphite rope filler is 3-8 mm, and the graphite rope filler is pre-compressed before being filled, which compresses it to 50-70% of the original diameter.

4. The method of claim 1, wherein: The pre-compression is realized by making the graphite rope filler pass through a pair of spacing-adjustable rollers or by radial extrusion using a clamp.

5. The method of claim 4, wherein: In step S7, the high-temperature resistant sealant is a silicone sealant.

6. The method of claim 1, wherein: In step S3, the outer surface of the alumina outer sleeve is subjected to surface roughening treatment during customization.

7. The method of claim 1, wherein: The surface roughening treatment adopts sandblasting treatment with 20-60 mesh sand particles to form a roughened surface with a roughness of Ra3.2 μm to Ra12.5 μm on the outer surface of the alumina outer sleeve.

8. The method of claim 7, wherein: In step S8, the curing is performed at room temperature or accelerated curing by heating, wherein the heating temperature is not more than 100℃ and the heating time is not more than 5 h.

9. The method of claim 1, wherein: In step S5, the graphite rope fillers are filled in segments along the axial direction of the annular gap, and the mechanical compaction is realized by segmental knocking.

10. The method of claim 1, wherein: ​

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