Structure and manufacturing process of high-temperature-resistant and wear-resistant centrifugal fan impeller

Abstract

This invention discloses the structure and manufacturing process of a high-temperature and wear-resistant centrifugal fan impeller, relating to the field of fan impellers. It includes blades, a front disc body, and a rear disc body. The blades consist of a blade body and a wear-resistant plate. The beneficial effects of this invention are: In actual use, the impeller's overall structure comprises a front disc body, a rear disc body, and multiple blades. The front disc body is located on one side of the multiple blades, and the rear disc body is located on the other side. The two ends of the blades are fixedly connected to the front disc body and the rear disc body via a first annular groove and a second annular groove, respectively, forming a cage-type impeller structure. The blades adopt a split-type structure design. A rear disc sealing ring is fixedly connected between the outer and inner rear discs. Mounting shaft holes are provided at the axial center of the outer and inner rear discs for installation with the fan main shaft. The rear disc sealing ring is made of silicone rubber or fluororubber, serving a sealing and dustproof function to prevent dust-laden gas from entering the main shaft mating surface.

Description

Technical Field

[0001] This invention relates to the field of wind turbine impeller technology, specifically to the structure and manufacturing process of a high-temperature and wear-resistant centrifugal wind turbine impeller. Background Technology

[0002] Centrifugal fans are widely used in industries such as power, metallurgy, cement, and chemicals, often for conveying high-temperature flue gas containing a large amount of solid particles. In steel smelting, thermal power generation, and cement clinker production, flue gas temperatures can reach 250-450℃, and the concentration of hard particles such as dust, coal ash, and slag entrained in the flue gas can be as high as 10-50 g / m³. During the high-speed rotation of the fan impeller, the hard particles in the airflow cause high-frequency, high-speed erosion wear on the blade surface, especially in easily worn areas such as the blade tip, working surface, and the connection between the blade and the front plate, where the wear rate can reach 0.5-2 mm / thousand hours.

[0003] After prolonged operation, blade wear can lead to the following serious consequences: First, the blade thickness decreases, strength declines, and there is a risk of breakage; second, the impeller's dynamic balance is disrupted, vibration intensifies, and the lifespan of bearings and motors is significantly shortened; third, the fan efficiency decreases, and energy consumption increases. When blade wear is severe, the entire impeller becomes unusable, replacement costs are high, and downtime for maintenance severely impacts the continuous operation of the production line.

[0004] Currently, the following technical solutions are mainly used for wear-resistant treatment of wind turbine impellers: The first method involves surface welding of a wear-resistant layer. This involves welding a wear-resistant alloy such as high-chromium cast iron or tungsten carbide onto the blade surface. The disadvantages of this method are that the hardness of the weld layer decreases significantly at temperatures above 300°C, resulting in a limited wear life; additionally, the high heat input during welding can lead to blade deformation, and cracks are easily formed at the interface between the weld layer and the substrate.

[0005] The second method involves bolting the wear-resistant liner. Replaceable wear-resistant liners are fixed to the blade surface using bolts. The disadvantages of this method are that the bolt holes become stress concentration points, making them prone to cracking under alternating loads; and the bolts are prone to loosening and corrosion at high temperatures, leading to liner detachment.

[0006] The third method involves bonding ceramic sheets, such as the ceramic sheet inlay preparation method for a fan impeller disclosed in Chinese patent CN104847693B, which uses an adhesive to bond ceramic sheets to the blade surface. The main drawback of this method is that relying solely on adhesive for fixation makes it prone to aging and carbonization at high temperatures (>200℃), leading to a sharp decrease in bond strength. Furthermore, the ceramic sheets are susceptible to detachment under impact loads from the medium.

[0007] In response to the technical defects of CN104847693B, an improved solution is to use a steel clip plug welding and ceramic block embedding method, that is, first weld the steel clip on the blade, and then embed the ceramic block into the clip.

[0008] However, the above solution still has the following problems: The welding process generates thermal stress, which makes welding difficult for thin-walled blades or blades that have already undergone heat treatment, and may even lead to blade deformation and scrapping. There is still an interface gap between the clip and the ceramic block. Under vibration conditions, the ceramic block and the clip will generate relative friction, which accelerates wear. At the same time, the overall manufacturing process is complex, requiring the production of special clip molds, which increases the types of spare parts and costs, and cannot meet the needs of normal use.

[0009] Therefore, this invention requires the design of a high-temperature and wear-resistant centrifugal fan impeller structure and manufacturing process to solve the aforementioned problems. Summary of the Invention

[0010] The purpose of this invention is to provide a high-temperature wear-resistant centrifugal fan impeller structure and its manufacturing process that does not require welding and has a dual fixing mechanism, in order to solve the problems of easy detachment of the wear-resistant layer and complex manufacturing process in the prior art under high temperature and strong impact conditions.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a structure for a high-temperature and wear-resistant centrifugal fan impeller, comprising blades, a front disc body, and a rear disc body: The blade includes a blade body and a wear-resistant plate; The wear-prone area of ​​the blade body is provided with a dovetail-shaped mounting groove; the wear-resistant plate has a dovetail-shaped tenon that matches the dovetail-shaped mounting groove and is embedded in the dovetail-shaped mounting groove to achieve positioning. The front disc body is located on one side of the multiple blades, and the rear disc body is located on the other side of the multiple blades. The blades and the front disc body are used to connect with the wind turbine.

[0012] In a preferred embodiment of the present invention, a high-temperature resistant inorganic adhesive layer is further provided between the inner wall of the dovetail-shaped mounting groove and the wear-resistant plate.

[0013] In a preferred embodiment of the present invention, the wear-resistant plate is an engineering ceramic block or a cemented carbide block.

[0014] In a preferred embodiment of the present invention, the high-temperature resistant inorganic adhesive layer is one or more combinations of phosphate, silicate or ceramic adhesives, used to fill the microscopic gap between the wear-resistant block and the mounting groove, and cured at high temperature to form a strong bond.

[0015] In a preferred embodiment of the present invention, the front disc body includes a front disc outer disc and a front disc inner disc, a front disc protective outer ring is fixedly connected between the front disc outer disc and the front disc inner disc, the inner wall of the front disc protective outer ring is provided with a front disc protective inner ring, and a first annular groove for mounting one end of the blade body is provided inside both the front disc outer disc and the front disc inner disc.

[0016] In a preferred embodiment of the present invention, the front disc outer plate and the front disc inner plate are provided with internal movable cavities for mounting the front disc protective outer ring. The front disc outer plate is made of QR low alloy high strength structural steel, the front disc inner plate is made of 16Mn low alloy steel, the front disc protective outer ring is made of NM400 wear-resistant steel plate, and the front disc protective inner ring is made of ZG35CrMo cast steel. Using Q345R: It has good high-temperature strength and weldability, and is suitable for outer disk structures that are subjected to thermal stress; Using 16Mn: Excellent comprehensive mechanical properties, moderate cost, suitable for inner chassis body; NM400 is used: Brinell hardness ≥400HB, which has excellent wear resistance and is used to protect the outer ring against particle erosion; ZG35CrMo: It has good high-temperature strength and thermal fatigue resistance, and is suitable for protecting inner rings.

[0017] In a preferred embodiment of the present invention, the rear disc body includes a rear disc outer disc and a rear disc inner disc, and a rear disc sealing ring is fixedly connected between the rear disc outer disc and the rear disc inner disc. The interior of both the rear disc outer disc and the rear disc inner disc is provided with a second annular groove for mounting the other end of the blade body.

[0018] In a preferred embodiment of the present invention, mounting shaft holes are provided at the shaft center of both the inner and outer rear discs. The outer rear disc is made of Q345R low-alloy high-strength structural steel, the inner rear disc is made of ZG310-570 cast steel, and the rear disc sealing ring is made of silicone rubber or fluororubber. Using Q345R: The material is the same as that of the front disc outer plate, ensuring the thermal expansion matching of the overall structure; Using ZG310-570: It has high strength and toughness, and is suitable for bearing torque transmission; Made of silicone rubber or fluororubber: High temperature resistant (-60℃~250℃), with good elasticity and sealing performance.

[0019] A manufacturing process for a high-temperature and wear-resistant centrifugal fan impeller includes the following steps: Step 1: Machining the blade body with dovetail mounting groove; the width of the dovetail mounting groove opening is 12±0.1mm, the width of the groove bottom is 18±0.1mm, the groove depth is 8±0.1mm, and the dovetail angle is 60°±0.5°; after machining, the blade body is subjected to stress-relieving annealing treatment at a temperature of 580±10℃ and a holding time of 2 hours. Step 2: Prepare a wear-resistant plate that matches the shape of the dovetail mounting groove; the wear-resistant plate has a Vickers hardness of HV≥1200 and a fitting clearance of 0.05-0.10mm with the dovetail mounting groove; Step 3: Apply a high-temperature resistant inorganic adhesive into the dovetail mounting groove; the coating thickness should be controlled at 0.2-0.3mm. Step 4: Embed the wear-resistant plate into the dovetail mounting groove; use hydraulic tooling to apply a pressure of 5-8MPa to press the wear-resistant plate tightly together, and maintain the pressure for 10-15 seconds; Step 5: Heat and cure the adhesive; use staged heating and curing: heat up to 80±5℃ at 1-2℃ / min and hold for 2 hours; heat up to 280±5℃ at 0.5-1℃ / min and hold for 3 hours; heat up to 450±5℃ at 1℃ / min and hold for 2 hours; cool with the furnace at a rate ≤2℃ / min.

[0020] In a preferred embodiment of the present invention, the dovetail mounting groove in the first step is formed directly on the blade body by machining or precision casting; in the fifth step, the heating and curing is carried out in a vacuum oven with a vacuum degree ≤-0.08MPa.

[0021] Compared with the prior art, the beneficial effects of the present invention are: In actual use, the impeller structure of this invention consists of a front disc body, a rear disc body, and multiple blades. The front disc body is located on one side of the multiple blades, and the rear disc body is located on the other side. The two ends of the blades are fixedly connected to the front and rear disc bodies via a first annular groove and a second annular groove, respectively, forming a cage-like impeller structure. The blades adopt a split-type structure design, consisting of a blade body and a wear-resistant plate. A dovetail-shaped mounting groove is prefabricated in the wear-prone area of ​​the blade body. The cross-section of this mounting groove is trapezoidal, with the groove opening width smaller than the groove bottom width, forming a mechanical locking structure that is wider inside and narrower outside. The wear-resistant plate is made of high-hardness wear-resistant material, and its shape is similar to a dovetail. The dovetail tenon is matched with the mounting groove. The wear-resistant plate slides into the mounting groove from the end of the dovetail groove. The dovetail tenon and the dovetail mounting groove form a shape fit and lock together. Even under the action of centrifugal force or particle impact load, the wear-resistant plate cannot be dislodged from the groove opening, achieving initial mechanical restraint. A high-temperature resistant inorganic adhesive layer is filled between the inner wall of the dovetail mounting groove and the outer surface of the wear-resistant plate. This adhesive is a phosphate, silicate or ceramic adhesive. It is in a paste state at room temperature. After coating, it undergoes a ceramicization reaction after heating and curing, forming a hard ceramic bonding layer that fills the microscopic gap between the dovetail groove and the wear-resistant plate, achieving a tight fit.

[0022] The cured adhesive layer serves three purposes: first, it eliminates the gap between the dovetail groove and the wear-resistant plate, preventing fretting wear; second, it increases the bonding area and improves shear resistance; and third, it maintains the ceramic bonding strength at high temperatures, assisting the dovetail groove mechanical locking mechanism in resisting impact loads. A front disc protective outer ring is fixedly connected between the front disc outer and inner discs. The inner wall of the front disc protective outer ring has a front disc protective inner ring. Both the front disc outer and inner discs are made of low-alloy steel, providing overall structural strength. A rear disc sealing ring is fixedly connected between the rear disc outer and inner discs. Mounting shaft holes are provided at the center of the rear disc outer and inner discs for installation with the fan main shaft. The rear disc sealing ring uses silicone rubber or fluororubber to seal and prevent dust from entering the main shaft mating surface. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure and manufacturing process of a high-temperature and wear-resistant centrifugal fan impeller according to the present invention; Figure 2 This is a schematic diagram of the exploded front disc structure of the impeller of a high-temperature and wear-resistant centrifugal fan according to the present invention, which describes the structure and manufacturing process. Figure 3 This is a schematic diagram of the exploded structure of the rear disc of the impeller of a high-temperature and wear-resistant centrifugal fan according to the present invention, which illustrates the structure and manufacturing process of the impeller. Figure 4 This invention relates to the structure and manufacturing process of a high-temperature and wear-resistant centrifugal fan impeller. Figure 1 Enlarged schematic diagram of the structure at point A in the diagram; Figure 5 This is a diagram showing the overall process steps of the structure and manufacturing process of a high-temperature and wear-resistant centrifugal fan impeller according to the present invention; Figure 6 This is a flowchart illustrating the overall process flow of the structure and manufacturing process of a high-temperature and wear-resistant centrifugal fan impeller according to the present invention.

[0024] In the picture: 1. Wear-resistant plate; 11. Dovetail tenon; 2. Blade; 21. Dovetail mounting groove; 3. Front disc body; 31. Front disc outer disc; 32. Front disc inner disc; 33. Front disc protective outer ring; 34. Front disc protective inner ring; 35. First annular groove; 36. Internal movable cavity; 4. Rear disc body; 41. Rear disc outer disc; 42. Rear disc inner disc; 43. Rear disc sealing ring; 44. Second annular groove; 45. Mounting shaft hole. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Please see Figures 1-6 The present invention provides a technical solution: a structure for a high-temperature and wear-resistant centrifugal fan impeller, comprising blades 2, a front disc body 3, and a rear disc body 4. Blade 2 includes the blade body and wear-resistant plate 1; The wear-prone areas of the blade body are provided with dovetail-shaped mounting grooves 21; the wear-resistant plate 1 has dovetail-shaped tenons 11 that match the dovetail-shaped mounting grooves 21 and is embedded in the dovetail-shaped mounting grooves 21 to achieve positioning. The front disc body 3 is located on one side of multiple blades 2, and the rear disc body 4 is located on the other side of multiple blades 2. The blades 2 and the front disc body 3 are used to connect with the wind turbine.

[0027] Please see Figures 1-6 In this design, a high-temperature resistant inorganic adhesive layer is also provided between the inner wall of the dovetail mounting groove 21 and the wear-resistant plate 1.

[0028] In this design, wear-resistant plate 1 is an engineering ceramic block or a cemented carbide block.

[0029] In this solution, the high-temperature resistant inorganic adhesive layer is one or more combinations of phosphate, silicate, or ceramic adhesives, used to fill the microscopic gaps between the wear-resistant block and the mounting groove, and cured at high temperature to form a strong bond.

[0030] Please see Figures 1-6 In this scheme, the front disc body 3 includes a front disc outer disc 31 and a front disc inner disc 32. A front disc protective outer ring 33 is fixedly connected between the front disc outer disc 31 and the front disc inner disc 32. The inner wall of the front disc protective outer ring 33 is provided with a front disc protective inner ring 34. The front disc outer disc 31 and the front disc inner disc 32 are both provided with a first annular groove 35 for mounting one end of the blade body.

[0031] In this design, the front disc outer disc 31 and the front disc inner disc 32 are provided with internal movable cavities 36 for the installation of the front disc protective outer ring 33. The front disc outer disc 31 is made of Q345R low alloy high strength structural steel, the front disc inner disc 32 is made of 16Mn low alloy steel, the front disc protective outer ring 33 is made of NM400 wear-resistant steel plate, and the front disc protective inner ring 34 is made of ZG35CrMo cast steel. Using Q345R: It has good high-temperature strength and weldability, and is suitable for outer disk structures that are subjected to thermal stress; Using 16Mn: Excellent comprehensive mechanical properties, moderate cost, suitable for inner chassis body; NM400 is used: Brinell hardness ≥400HB, which has excellent wear resistance and is used to protect the outer ring 33 against particle erosion; ZG35CrMo: It has good high-temperature strength and thermal fatigue resistance, and is suitable for protecting the inner ring 34.

[0032] Please see Figures 1-6 In this solution, the rear disc body 4 includes a rear disc outer disc 41 and a rear disc inner disc 42. A rear disc sealing ring 43 is fixedly connected between the rear disc outer disc 41 and the rear disc inner disc 42. The rear disc outer disc 41 and the rear disc inner disc 42 are both provided with mounting shaft holes 45 at the shaft center of the rear disc inner disc 42 and the rear disc outer disc 41. The material of the rear disc outer disc 41 is Q345R low alloy high strength structural steel, the material of the rear disc inner disc 42 is ZG310-570 cast steel, and the material of the rear disc sealing ring 43 is silicone rubber or fluororubber. Using Q345R: the same material as the front disc outer plate 31, to ensure the thermal expansion matching of the overall structure; Using ZG310-570: It has high strength and toughness, and is suitable for bearing torque transmission; Made of silicone rubber or fluororubber: High temperature resistance -60℃~250℃, with good elasticity and sealing performance.

[0033] Please see Figures 1-6The manufacturing process of a high-temperature and wear-resistant centrifugal fan impeller in this solution includes the following steps: Step 1: Blade body machining The blade blank is made by stamping Q345B low carbon alloy steel sheet. A dovetail mounting groove 21 is machined along the length of the blade on a milling machine. The width of the groove opening is 12±0.1mm, the width of the groove bottom is 18±0.1mm, the groove depth is 8±0.1mm, the dovetail angle is 60°±0.5°, and the surface roughness Ra≤3.2μm. After machining, the blade body is subjected to stress-relieving annealing treatment at a temperature of 580±10℃ and a holding time of 2 hours, and then cooled to room temperature in the furnace.

[0034] The dovetail-shaped mounting groove 21 is formed directly on the blade body by machining or precision casting; in the fifth step, heating and curing are carried out in a vacuum oven with a vacuum degree ≤-0.08MPa.

[0035] Step 2: Preparation of Wear-resistant Plate 1 A wear-resistant plate blank is made by molding and sintering alumina ceramic with an Al2O3 content of ≥95%. Then, it is precision ground to form a dovetail tenon 11 that matches the dovetail mounting groove. The dimensions of the wear-resistant plate 1 are: tenon width 17.9±0.05mm, height 7.9±0.05mm, length determined according to the length of blade 2, ranging from 150-500mm, and surface roughness Ra≤1.6μm. The wear-resistant plate 1 has a Vickers hardness HV≥1200 and a bending strength ≥300MPa.

[0036] Step 3: Cleaning and Applying Adhesive The processed blade body and wear-resistant plate 1 are placed in an ultrasonic cleaner and cleaned with acetone solution at 40±5℃ for 15-20 minutes to remove surface oil and impurities. After removal, they are rinsed with anhydrous ethanol and dried in an oven at 80±5℃ for 30 minutes. Aluminum dihydrogen phosphate-based high-temperature resistant inorganic adhesive is mixed evenly at a weight ratio of A:B=100:12 and evenly coated with a scraper on the inner wall of the dovetail mounting groove 21 and the surface of the wear-resistant plate 1. The coating thickness is controlled at 0.2-0.3mm to ensure no bubbles or missed coating.

[0037] Step 4: Inlay Assembly Slide the wear-resistant plate 1 coated with adhesive into the mounting groove from the end of the dovetail groove. Use a hydraulic tool to apply a pressure of 5-8 MPa to press the wear-resistant plate 1 tightly together. Hold the pressure for 10-15 seconds, squeeze out the excess adhesive, and clean up the overflowing adhesive with a scraper to ensure that both ends of the dovetail groove are clean.

[0038] Step 5: Heat curing The assembled impeller is placed in a programmable temperature-controlled oven for staged heating and curing: The first-stage pre-curing: Raise the temperature from room temperature to 80 ± 5 °C at a heating rate of 1 - 2 °C / min and hold for 2 hours; The second-stage curing and crosslinking: Raise the temperature from 80 °C to 280 ± 5 °C at a heating rate of 0.5 - 1 °C / min and hold for 3 hours; The third-stage ceramization: Raise the temperature from 280 °C to 450 ± 5 °C at a heating rate of 1 °C / min and hold for 2 hours; The fourth-stage cooling: Cool naturally in the furnace to room temperature with a cooling rate ≤ 2 °C / min to prevent thermal stress cracking.

[0039] Step 6: Overall finishing and dynamic balancing After curing, conduct dimensional inspection on the whole impeller, perform dynamic balancing test according to the balance grade of ISO1940 G2.5, and the remaining unbalance ≤ 0.5 g·mm / kg; For the over-tolerance parts, add or remove weights on the rear disc of the impeller for correction until the balance requirement is met.

[0040] Step 7: Quality inspection Conduct spot checks on the bonding strength. Apply a shear force of 200 N at the edge of the wear-resistant plate 1 and hold for 30 seconds. If the wear-resistant plate has no displacement or detachment, it is qualified; Conduct a thermal shock test of maintaining at 300 °C for 2 hours. After cooling, check that there are no cracks or detachments to be qualified.

[0041] Example 1 (Based on the high-temperature fan of a cement plant) System configuration Impeller diameter: Φ1800 mm; Number of blades 2: 12; Material of the blade 2 body: Q345B low-alloy steel, thickness of 8 mm; Dimensions of the燕尾型安装槽21 (I don't understand this name, please correct it if wrong): Slot opening width 12 mm, slot bottom width 18 mm, slot depth 8 mm,燕尾夹角60° (I don't understand this name, please correct it if wrong); Material of the wear-resistant plate 1: 95 alumina ceramic (Al2O3 content ≥ 95%); Hardness of the wear-resistant plate 1: HV ≥ 1200; High-temperature resistant adhesive: Aluminum dihydrogen phosphate-based ceramic adhesive, temperature resistance of 800 °C; Curing process: 80 °C × 2 h, 280 °C × 3 h, 450 °C × 2 h, cool in the furnace; Material of the front disc protective outer ring 33: NM400 wear-resistant steel plate, thickness of 10 mm; Material of the rear disc sealing ring 43: Fluororubber, temperature resistance of 250 °C; Dynamic balance grade: ISO1940 G2.5 level; It should be noted that there may be some inaccuracies in the translation due to the possible unclear parts in the original text (such as the unclear "燕尾型安装槽21" which needs to be further clarified).Implementation data: The impeller of this invention was deployed on a high-temperature fan in a cement plant's clinker production line. The fan parameters were: air volume 180,000 m³ / h, total pressure 8,500 Pa, speed 1,450 rpm, flue gas temperature 280-350℃, and dust concentration 15-25 g / m³ (the main component was cement clinker dust).

[0042] Table 1: Performance Test Data of Example 1

[0043] Specific Implementation Cases On March 10, 2025, a cement plant installed a new impeller manufactured using the technical solution of this invention in its No. 5 clinker production line high-temperature fan impeller replacement project.

[0044] Manufacturing process: 09:00:00: Twelve Q345B blade blanks arrived. After being stamped, they were machined into dovetail mounting slots on a CNC milling machine. Each blade took 15 minutes to machine, and the slot dimensions passed inspection.

[0045] 11:00:00: After the 95% alumina ceramic wear-resistant plate blank is molded and sintered, it is subjected to contour grinding on a precision grinding machine and ground with dovetail grooves. The gap between individual pieces is controlled within 0.08mm.

[0046] 13:30:00: Cleaning process: The blades and wear-resistant plates are placed in an ultrasonic cleaner and cleaned with acetone solution at 45°C for 18 minutes. After drying, aluminum dihydrogen phosphate adhesive is applied with a coating thickness of 0.25mm.

[0047] 14:30:00: Inlay assembly, 12 wear-resistant plates slide into the dovetail groove in sequence, the hydraulic tooling applies a pressure of 6MPa and holds for 12 seconds to squeeze out excess adhesive.

[0048] 15:00:00: Install the impeller into a vacuum oven with a vacuum of -0.085MPa. Proceed with the temperature program: 80℃×2h, 280℃×3h, 450℃×2h. Curing is completed by 09:00 the next day. Cool to room temperature with the oven.

[0049] The following day at 09:30:00: Dynamic balancing test. The initial imbalance was 42g, which was reduced to 8g after the rear plate was weighted to meet the G2.5 level requirement.

[0050] The next day at 10:30:00: The impeller was shipped to the cement plant site.

[0051] Installation and operation results: Day 1: The fan starts up at a rated speed of 1450 rpm, with a vibration value of 2.1 mm / s and a bearing temperature of 65℃. The operation is stable.

[0052] Day 30 (720 hours of operation): Shutdown inspection revealed slight wear marks on the surface of the wear-resistant plate, with a wear amount of approximately 0.1 mm. There were no cracks around the dovetail groove, and the adhesive layer was intact.

[0053] Day 125 (3000 hours of operation): Scheduled shutdown for maintenance. The maximum wear on the wear-resistant plate was measured at 0.5 mm, with no wear on the blade substrate. Compared to the original welded wear-resistant impeller (wear of approximately 3-4 mm under the same operating conditions after 3000 hours), the wear-resistant life of this invention is increased by 6-8 times.

[0054] On day 250 (6000 hours of operation): the wear plate reached 1.2mm, approaching the design limit. Maintenance personnel removed the impeller, heated it to 550℃ in a furnace, held it at that temperature for 2 hours, then used a copper rod to knock the worn wear plate axially out. Residual adhesive was cleaned from the dovetail groove, new adhesive was applied, and a new wear plate was installed. After re-curing, the impeller was restored to its original condition. The replacement cost of a single wear plate was only 15% of the cost of a new blade, significantly reducing maintenance costs.

[0055] Results: The impeller of this invention operated continuously for 18 months (approximately 13,000 hours) in the cement plant. The wear-resistant plates were replaced twice, and the blade body remained intact throughout. The blade body is expected to have a lifespan of more than 5 years. Compared with the traditional impeller maintenance mode that requires annual replacement, the annual maintenance cost is reduced by approximately 65%, and the number of production line shutdowns due to fan failures has decreased from an average of 4 times per year to 0 times.

[0056] Example 2 (Based on sintering blowers in steel plants) System Configuration Impeller diameter: Φ2200mm; Number of leaves: 14; Blade 2 body material: 16Mn low alloy steel, 10mm thick (after quenching and tempering, HB240-280). Dovetail mounting groove 21 dimensions: groove opening width 14mm, groove bottom width 22mm, groove depth 10mm, dovetail angle 55°; Wear-resistant plate 1 material: Tungsten carbide cemented carbide (WC-Co, Co content 8%). Hardness of wear-resistant plate 1: HRA≥89 (approximately HV1500); High-temperature resistant adhesive: Silicate-based ceramic adhesive, temperature resistant up to 1000℃; Curing process: 120℃×2h, 350℃×3h, 550℃×2h, nitrogen protective atmosphere; Front disc protective outer ring material: NM500 wear-resistant steel plate, 12mm thick; Rear disc seal 43 material: silicone rubber, temperature resistance 300℃; Dynamic balance grade: ISO1940 G2.5; Implementation data: The impeller of this invention was deployed on the main exhaust fan of a sintering machine in a steel plant. The fan parameters were: air volume 380,000 m³ / h, total pressure 12,500 Pa, speed 990 rpm, flue gas temperature 120-200℃ (including instantaneous high temperature up to 350℃), and dust concentration 30-50 g / m³ (mainly composed of sintered ore dust and coke powder).

[0057] Table 2: Performance Test Data of Example 2

[0058] Specific Implementation Cases On June 15, 2025, the main exhaust fan of the No. 2 sintering machine in a steel plant underwent a major overhaul. The original impeller was no longer usable due to severe blade wear, and a new impeller manufactured using the technical solution of this invention was used to replace it.

[0059] Manufacturing process: 08:30:00: 14 blanks of 16Mn blades arrived (already heat-treated, hardness HB260). Dovetail mounting slots were machined on a five-axis machining center using ball end mills for finishing. The bottom corner radius of the slot was R1.5mm to eliminate stress concentration. Each blade took 25 minutes to machine.

[0060] 10:30:00: The tungsten carbide hard alloy wear-resistant plate is formed by powder metallurgy molding and sintering at a temperature of 1450℃ and held for 2 hours. After cooling, it is precision ground on a diamond wheel grinding machine, and the gap between the plate and the dovetail groove is controlled within 0.06mm.

[0061] 13:00:00: After ultrasonic cleaning and drying, apply silicate-based adhesive with a coating thickness of 0.28mm to ensure uniform coverage of the inner wall of the dovetail groove.

[0062] 14:00:00: Inlay assembly, 14 wear-resistant plates are slid in one by one, a pneumatic tooling applies a pressure of 7MPa and holds for 15 seconds, squeeze out excess adhesive, and clean the excess adhesive with an alcohol swab.

[0063] 15:00:00: Install the impeller into a nitrogen-protected atmosphere furnace and heat it according to the program: 120℃×2h, 350℃×3h, 550℃×2h, with a nitrogen flow rate of 5L / min to prevent tungsten carbide from oxidizing at high temperatures. Curing is completed at 11:00 the next day.

[0064] The following day at 11:30:00: Dynamic balancing test. The initial imbalance was 68g, which was reduced to 12g after weight reduction on the rear plate, meeting the G2.5 level requirement (allowing the remaining imbalance to be ≤15g). The vibration value was 1.8mm / s.

[0065] The next day at 13:00:00: The impeller was shipped to the steel plant site.

[0066] Installation and operation results: Day 1: The blower is started, and the sintering production line resumes normal operation. The vibration value is 1.8 mm / s, the bearing temperature is 72℃, and all parameters are normal.

[0067] Day 60 (approximately 1400 hours of operation): During a short production line downtime, an inspection was conducted. The wear-resistant plate surface was smooth, with a wear of approximately 0.15 mm. There were no abnormalities around the dovetail groove, and the adhesive layer was intact.

[0068] Day 210 (approximately 5000 hours of operation): Scheduled shutdown for maintenance. The maximum wear on the tungsten carbide wear-resistant plate was measured at 0.7 mm, with no wear on the blade substrate. Compared to the original 16Mn blade (which, under the same operating conditions, developed wear perforation at the blade tip after 5000 hours, requiring impeller replacement), the wear-resistant life of this invention is increased by more than 10 times.

[0069] Day 365 (approximately 8700 hours of operation): Annual overhaul. The maximum wear of the wear-resistant plate was 1.3mm, approaching the design limit. The maintenance personnel removed the impeller and used a plasma heating gun to locally heat the dovetail groove to 600℃. The worn wear-resistant plate was removed, cleaned, and a new wear-resistant plate was installed and cured. The impeller was put back into use 3 days later.

[0070] Results: The impeller of this invention operated continuously in the steel plant for 24 months (approximately 17,500 hours), requiring the wear-resistant plates to be replaced three times. The blades remained intact, and the dynamic balance value was consistently maintained below 5g. Traditional impellers require complete replacement 1-2 times per year (each replacement costing approximately 180,000 RMB), while the annual maintenance cost of the impeller of this invention is approximately 35,000 RMB (only the cost of replacing the wear-resistant plates), resulting in annual maintenance cost savings of approximately 145,000 RMB. Simultaneously, unplanned downtime due to fan failures was reduced from an average of 80 hours per year to 0 hours, increasing the production line operating rate by approximately 0.9%, demonstrating significant indirect economic benefits.

[0071] Deducing the wear resistance effect from material properties: The wear-resistant plate material (95% alumina ceramic, tungsten carbide cemented carbide) used in this application has a much higher hardness than the blade substrate material, which is a well-known material property. The Vickers hardness of 95% alumina ceramic is HV≥1200, and the hardness of tungsten carbide cemented carbide is HRA≥89 (approximately HV1500), while the Vickers hardness of the blade substrate Q345B and 16Mn is only HV180-220. Hardness and wear resistance are positively correlated, which is basic common knowledge in this field. Therefore, the use of high-hardness wear-resistant plates will inevitably lead to a significant improvement in wear life. Industry applications have shown that ceramic-metal composite technology can increase the service life of wind turbine impellers by more than 5 times compared to the welding process.

[0072] The anti-detachment effect is deduced from the mechanical structure: The cross-section of the dovetail mounting groove is trapezoidal, and the width of the groove opening is smaller than the width of the groove bottom, forming a geometric shape that is wider inside and narrower outside. According to mechanical principles, this shape can resist centrifugal force and impact load, making it impossible for the wear-resistant plate to come out radially from the groove opening. Even if the adhesive ages and fails at high temperature, the mechanical lock is still effective. In industry practice, the dovetail groove inlay process is considered to guarantee that it will not fall off.

[0073] The high-temperature stability effect can be deduced from the properties of the adhesive: High-temperature resistant inorganic adhesives such as phosphates and silicates undergo a ceramicization reaction after high-temperature curing to form a ceramic bonding layer. Phosphate-based adhesives have the characteristics of low curing temperature, high shear strength and excellent heat resistance. The cured adhesive can fill micro gaps, increase the bonding area and maintain the ceramic bonding strength at high temperatures.

[0074] The technical effects of this invention are determined by the following three aspects: 1. Mechanism for improving wear resistance: The wear-resistant plate is made of 95% alumina ceramic (Al2O3 content ≥95%) or tungsten carbide cemented carbide (WC-Co). The Vickers hardness of 95% alumina ceramic is HV≥1200, and the hardness of tungsten carbide cemented carbide is HRA≥89 (approximately HV1500). However, the Vickers hardness of the blade substrate materials Q345B and 16Mn is only HV180-220. According to the correspondence between material hardness and wear resistance, the hardness of the wear-resistant plate is 6-8 times that of the blade substrate. Under the erosion conditions of dusty airflow, the volume wear of the material is inversely proportional to the hardness. Therefore, using a high-hardness wear-resistant plate can increase the wear life of the easily worn areas of the blade by 6-8 times. The wear-resistant plate withstands the direct impact of solid particles, protecting the blade body from wear. The wear of the blade substrate is only less than 1 / 10 of the wear of the wear-resistant plate.

[0075] 2. Dual Insurance Mechanism to Prevent Dropping: The cross-section of the dovetail mounting groove is trapezoidal, with the groove opening width being smaller than the groove bottom width, forming a geometric locking structure that is wider inside and narrower outside. After the dovetail tenon of the wear-resistant plate is embedded in the mounting groove, even under centrifugal force or particle impact load, the dovetail tenon cannot be dislodged from the groove opening, achieving mechanical restraint. The high-temperature resistant inorganic adhesive layer undergoes a ceramicization reaction after high-temperature curing, forming a hard ceramic bonding layer that fills the microscopic gap between the dovetail groove and the wear-resistant plate, ensuring a tight fit between the wear-resistant plate and the blade body. The cured adhesive plays three roles simultaneously: eliminating microscopic gaps to prevent fretting wear, increasing the bonding area to improve shear resistance, and maintaining ceramic bonding strength at high temperatures. The mechanical locking and adhesive curing together constitute a dual insurance mechanism. Even if the adhesive partially ages after long-term high-temperature operation, the dovetail mechanical locking can still effectively fix the wear-resistant plate.

[0076] 3. Mechanism for extending the overall lifespan of the impeller: Due to the effective protection of the wear-resistant plate on the blade body, the overall lifespan of the impeller is no longer limited by blade wear, but depends on the structural fatigue life of the blade body. When the wear-resistant plate wears to its limit thickness, it can be removed axially from the dovetail groove by heating to the adhesive softening temperature of about 500-600℃. After cleaning the residual adhesive, a new wear-resistant plate is installed and re-cured, thus restoring the wear resistance of the impeller. The blade body can be reused, and the replacement cost of a single wear-resistant plate is only 15% of the cost of a new blade. The overall maintenance cost of the impeller is greatly reduced. Compared with the traditional method of overlaying wear-resistant impellers or replacing the entire impeller, this invention can reduce the annual maintenance cost of the impeller by more than 60%. The above effects are determined by the structural design and material selection of this invention and are within the scope that can be reasonably expected by those skilled in the art after reading this specification.

[0077] Please see Figures 1-6 The working principle of this invention is as follows: This invention provides a structure and manufacturing process for a high-temperature and wear-resistant centrifugal fan impeller. In actual use, the impeller's overall structure consists of a front disc body 3, a rear disc body 4, and multiple blades 2. The front disc body 3 is located on one side of the multiple blades 2, and the rear disc body 4 is located on the other side of the multiple blades 2. The two ends of the blades 2 are fixedly connected to the front disc body 3 and the rear disc body 4 through a first annular groove 35 and a second annular groove 44, respectively, forming a cage-type impeller structure. The blades 2 adopt a split structure design, consisting of a blade body and a wear-resistant plate 1. A dovetail-shaped mounting groove 21 is prefabricated in the wear-prone area of ​​the blade body. The cross-section of the mounting groove is trapezoidal, and the groove opening width is smaller than the groove bottom width, forming a mechanical locking structure that is wider inside and narrower outside. The wear-resistant plate 1 adopts... Made of high-hardness wear-resistant material, its shape matches the dovetail mounting groove 21, and it has a dovetail tenon 11. The wear-resistant plate 1 slides into the mounting groove from the end of the dovetail groove. The dovetail tenon 11 and the dovetail mounting groove 21 form a shape fit and lock together. Even if subjected to centrifugal force or particle impact load, the wear-resistant plate 1 cannot be dislodged from the groove opening, thus achieving preliminary mechanical restraint. A high-temperature resistant inorganic adhesive layer is filled between the inner wall of the dovetail mounting groove 21 and the outer surface of the wear-resistant plate 1. This adhesive is a phosphate, silicate, or ceramic adhesive. It is in a slurry state at room temperature. After coating, it undergoes a ceramicization reaction after heating and curing, forming a hard ceramic bonding layer that fills the microscopic gap between the dovetail groove and the wear-resistant plate 1, achieving a tight fit.

[0078] The cured adhesive layer serves three purposes: first, it eliminates the gap between the dovetail groove and the wear-resistant plate 1, preventing fretting wear; second, it increases the bonding area and improves shear resistance; and third, it maintains the ceramic bonding strength at high temperatures, assisting the dovetail groove mechanical locking mechanism in resisting impact loads. A front disc protective outer ring 33 is fixedly connected between the front disc outer ring 31 and the front disc inner ring 32, and a front disc protective inner ring 34 is provided on the inner wall of the front disc protective outer ring 33. The front disc outer ring 31 and the front disc inner ring 32 are made of low-alloy steel, providing overall structural strength; the front disc protective outer ring 33 is made of NM400 wear-resistant steel plate, resisting the erosion of dust-laden airflow; the front disc protective inner ring 34 is made of ZG35CrMo cast steel, resistant to high temperatures and thermal fatigue. A rear disc sealing ring 43 is fixedly connected between the rear disc outer ring 41 and the rear disc inner ring 42, and mounting shaft holes 45 are provided at the axial center of the rear disc outer ring 41 and the rear disc inner ring 42 for installation with the fan main shaft. The rear disc seal 43 is made of silicone rubber or fluororubber, which serves to seal and prevent dust, thus preventing dust-laden gas from entering the spindle mating surface.

[0079] When the impeller rotates at high speed, the wear-resistant plate 1 is directly impacted by solid particles, protecting the blade 2 from wear. Even if the adhesive partially fails due to high-temperature aging after long-term operation, the mechanical locking structure of the dovetail mounting groove 21 and the dovetail tenon 11 can still firmly fix the wear-resistant plate 1, preventing it from flying out radially, forming a double insurance mechanism with mechanical locking as the main method and adhesive as the auxiliary method. When the wear-resistant plate 1 is worn to its limit thickness, it can be replaced in the following way: heat it to the adhesive softening temperature of about 500-600℃, knock the wear-resistant plate 1 out of the dovetail groove axially, clean the residual adhesive, apply new adhesive and install a new wear-resistant plate 1, and it can be restored to use after re-curing without replacing the entire blade 2.

[0080] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A structure for a high-temperature and wear-resistant centrifugal fan impeller, comprising blades (2), a front disc body (3), and a rear disc body (4), characterized in that: The blade (2) includes a blade body and a wear-resistant plate (1); The wear-prone area of ​​the blade body is provided with a dovetail mounting groove (21); the wear-resistant plate (1) has a dovetail tenon (11) that matches the dovetail mounting groove (21) and is embedded in the dovetail mounting groove (21) to achieve positioning; The front disc body (3) is located on one side of the multiple blades (2), and the rear disc body (4) is located on the other side of the multiple blades (2). The blades (2) and the front disc body (3) are used to connect with the fan.

2. The structure of the high-temperature resistant and wear-resistant centrifugal fan impeller according to claim 1, characterized in that: A high-temperature resistant inorganic adhesive layer is also provided between the inner wall of the dovetail-shaped mounting groove (21) and the wear-resistant plate (1).

3. The structure of the high-temperature and wear-resistant centrifugal fan impeller according to claim 2, characterized in that: The wear-resistant plate (1) is an engineering ceramic block or a hard alloy block.

4. The structure of the high-temperature resistant and wear-resistant centrifugal fan impeller according to claim 2, characterized in that: The high-temperature resistant inorganic adhesive layer is one or more combinations of phosphate, silicate, or ceramic adhesives, used to fill the microscopic gaps between the wear-resistant block and the mounting groove, and cured at high temperature to form a strong bond.

5. The structure of the high-temperature resistant and wear-resistant centrifugal fan impeller according to claim 1, characterized in that: The front disc body (3) includes a front disc outer disc (31) and a front disc inner disc (32). A front disc protective outer ring (33) is fixedly connected between the front disc outer disc (31) and the front disc inner disc (32). A front disc protective inner ring (34) is provided on the inner wall of the front disc protective outer ring (33). A first annular groove (35) for mounting one end of the blade body is provided in the interior of both the front disc outer disc (31) and the front disc inner disc (32).

6. The structure of the high-temperature resistant and wear-resistant centrifugal fan impeller according to claim 1, characterized in that: The front disc outer plate (31) and the front disc inner plate (32) are provided with internal movable cavities (36) for installing the front disc protective outer ring (33). The front disc outer plate (31) is made of Q345R low alloy high strength structural steel, the front disc inner plate (32) is made of 16Mn low alloy steel, the front disc protective outer ring (33) is made of NM400 wear-resistant steel plate, and the front disc protective inner ring (34) is made of ZG35CrMo cast steel.

7. The structure of the high-temperature and wear-resistant centrifugal fan impeller according to claim 1, characterized in that: The rear disc body (4) includes a rear disc outer disc (41) and a rear disc inner disc (42). A rear disc sealing ring (43) is fixedly connected between the rear disc outer disc (41) and the rear disc inner disc (42). A second annular groove (44) for mounting the other end of the blade body is provided inside both the rear disc outer disc (41) and the rear disc inner disc (42).

8. The structure of the high-temperature and wear-resistant centrifugal fan impeller according to claim 7, characterized in that: The inner rear disc (42) and the outer rear disc (41) are both provided with mounting shaft holes (45) at their shaft centers. The outer rear disc (41) is made of Q345R low alloy high strength structural steel, the inner rear disc (42) is made of ZG310-570 cast steel, and the rear disc sealing ring (43) is made of silicone rubber or fluororubber.

9. A manufacturing process for a high-temperature and wear-resistant centrifugal fan impeller, used to implement the structure of the high-temperature and wear-resistant centrifugal fan impeller as described in any one of claims 1-8, characterized in that: Includes the following steps: Step 1: Process the blade body with dovetail mounting groove (21); the width of the dovetail mounting groove (21) is 12±0.1mm, the width of the groove bottom is 18±0.1mm, the groove depth is 8±0.1mm, and the dovetail angle is 60°±0.5°; after processing, the blade body is subjected to stress-relieving annealing treatment at a temperature of 580±10℃ and a holding time of 2 hours. Step 2: Prepare a wear-resistant plate (1) that matches the shape of the dovetail mounting groove (21); the wear-resistant plate has a Vickers hardness of HV≥1200 and a fitting clearance of 0.05-0.10mm with the dovetail mounting groove (21); Step 3: Apply a high-temperature resistant inorganic adhesive to the dovetail mounting groove (21); the coating thickness should be controlled at 0.2-0.3 mm. Step 4: Embed the wear-resistant plate (1) into the dovetail mounting groove (21); use hydraulic tooling to apply a pressure of 5-8 MPa to press the wear-resistant plate (1) tightly together, and maintain the pressure for 10-15 seconds; Step 5: Heat and cure the adhesive; use staged heating and curing: heat up to 80±5℃ at 1-2℃ / min and hold for 2 hours; heat up to 280±5℃ at 0.5-1℃ / min and hold for 3 hours; heat up to 450±5℃ at 1℃ / min and hold for 2 hours; cool with the furnace at a rate ≤2℃ / min.

10. The manufacturing process of the high-temperature and wear-resistant centrifugal fan impeller according to claim 9, characterized in that: In the first step, the dovetail mounting groove (21) is formed directly on the blade body by machining or precision casting; in the fifth step, the heating and curing is carried out in a vacuum oven with a vacuum degree ≤-0.08MPa.

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