Gas phase infiltration apparatus for turbine blades

Abstract

The embodiments of the present disclosure disclose a vapor infiltration device applied to a turbine blade. A specific embodiment of the device comprises a lower base, a preheating chamber, a transition support base, a multi-stage gas distribution chamber and an upper base arranged coaxially with the center. The lower base is connected to an air inlet pipeline, and mixed gas flows in the pipeline. The preheating chamber is arranged at the top end of the lower base, and the preheating chamber contains aluminum particles. The mixed gas enters the preheating chamber through the lower base and reacts with the aluminum particles to form process gas. The transition support base is arranged at the top end of the preheating chamber, and the multi-stage gas distribution chamber is arranged at the top end of the transition support base and connected to the preheating chamber. The turbine blade is fixed in the multi-stage gas distribution chamber. The upper base is arranged at the top end of the multi-stage gas distribution chamber, and the upper base is provided with an air outlet hole. The process gas penetrates into the surface of the turbine blade through the multi-stage gas distribution chamber and is finally discharged through the air outlet hole. The embodiment can improve the production efficiency.

Description

Technical Field

[0001] The embodiments disclosed herein relate to the field of high-temperature protective coating preparation technology, specifically to a vapor phase infiltration device applied to turbine blades. Background Technology

[0002] Turbine blades need to operate stably for extended periods in extreme high-temperature, high-pressure, and oxidizing / corrosive environments, making surface treatment crucial. Vapor phase infiltration (VPI), as an advanced surface treatment technology, is widely used to improve key properties of turbine blades, such as wear resistance, corrosion resistance, and high-temperature stability. Currently, the commonly used VPI process involves placing the blade to be treated along with solid raw materials (such as aluminum granules) needed to generate the active gas in a monolithic reaction vessel. The reaction takes place within the vessel, and the gas flows across the blade surface to deposit a coating.

[0003] However, in practice, it has been found that when the above method is used for vapor phase infiltration treatment, the active gas is difficult to distribute evenly when flowing through the stacked blades, resulting in poor consistency of the coating thickness on the blade surface. At the same time, the slag generated in the reaction vessel is spread throughout the inner cavity of the vessel. The device must be completely disassembled during subsequent cleaning, which is a complicated and time-consuming process, resulting in long equipment downtime and often leading to technical problems of low production efficiency.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background of the inventive concept, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The summary portion of this disclosure is intended to provide a brief overview of the concepts, which will be described in detail in the detailed description portion. This summary portion is not intended to identify key or essential features of the claimed technical solutions, nor is it intended to limit the scope of the claimed technical solutions.

[0006] Some embodiments of this disclosure propose a vapor phase infiltration device for turbine blades to solve one or more of the technical problems mentioned in the background section above.

[0007] Some embodiments of this disclosure provide a vapor phase infiltration device for turbine blades. The device includes: a lower base, a preheating chamber, a transition support, a multi-stage gas distribution chamber, and an upper base, all coaxially arranged. The lower base is connected to an intake pipe, through which a mixed gas flows. The preheating chamber is located at the top of the lower base and contains aluminum particles. The mixed gas enters the preheating chamber through the lower base and reacts with the aluminum particles to form process gas. The transition support is located at the top of the preheating chamber, and the multi-stage gas distribution chamber is located at the top of the transition support and connected to the preheating chamber. The interior includes at least one gas distribution seat and at least one blade base. The gas distribution seat includes a distribution base and a distribution disk. The distribution disk is provided with an array of air passage holes and is embedded inside the distribution base. The blade base is located at the top of the distribution base and is provided with a blade mounting groove corresponding to the array of air passage holes. The edge of the blade mounting groove is provided with an array of air distribution holes. The turbine blade is fixed through the blade mounting groove. The upper base is located at the top of the multi-stage gas distribution chamber and is provided with an exhaust hole. The process gas permeates into the surface of the turbine blade through the multi-stage gas distribution chamber and is finally discharged through the exhaust hole.

[0008] Optionally, the lower base includes a flange, an air guide base, a first sleeve, and a base plate; the flange is horizontally arranged, one end of the air guide base passes through the flange and is connected to the air inlet pipe, the first sleeve is disposed on the flange and coaxially sleeved on the outside of the air guide base, and the base plate is disposed at the top of the first sleeve; the other end of the air guide base passes through the base plate and is connected to the preheating chamber.

[0009] Optionally, the preheating chamber includes a second sleeve and an aluminum generator, wherein the aluminum generator is nested inside the second sleeve; and the aluminum granules are disposed inside the aluminum generator.

[0010] Optionally, the multi-stage gas distribution chamber further includes at least one third sleeve; the third sleeve is disposed at the top of the blade base, and the turbine blade is disposed inside the third sleeve.

[0011] Optionally, the multi-stage gas distribution chamber further includes a blade fixture, which can be embedded in the blade mounting slot; the bottom of the turbine blade is embedded inside the blade fixture for fixation.

[0012] Optionally, all structural components in the above-mentioned vapor phase infiltration device are made of graphite material.

[0013] Optionally, the vapor phase infiltration device applied to turbine blades further includes a protective ring, a thermocouple, and a heating shroud; the protective ring is disposed at the top of the lower base, and the preheating chamber is nested within the protective ring; one end of the thermocouple is embedded in the protective ring, and the other end extends to the upper base; the heating shroud covers the vapor phase infiltration device, the heating shroud can provide a heat source for the vapor phase infiltration device, and the thermocouple can detect the temperature inside the heating shroud.

[0014] Optionally, the above-mentioned gas phase permeation device for turbine blades further includes a top cover; the top of the upper base is provided with an annular sealing groove, the air outlet is coaxially arranged with the annular sealing groove, and fine sand is placed in the annular sealing groove; the top cover is provided with an annular boss that matches the annular sealing groove, the width of the annular sealing groove is greater than the width of the annular boss, and the annular boss can be embedded in the fine sand in the annular sealing groove; after the top cover is installed, the height of the fine sand is consistent with the height of the annular sealing groove; the process gas passes through the air outlet and is discharged through the fine sand between the annular boss and the annular sealing groove.

[0015] The above-described embodiments of this disclosure have the following beneficial effects: the vapor phase infiltration device applied to turbine blades according to some embodiments of this disclosure can improve production efficiency. Specifically, the reason for the low production efficiency is that the active gas is difficult to distribute evenly when flowing through the stacked blades, resulting in poor consistency of the coating thickness on the blade surface. At the same time, the slag generated in the reaction vessel is distributed throughout the inner cavity of the vessel, and the device must be completely disassembled for subsequent cleaning, which is cumbersome and time-consuming, resulting in long equipment downtime and low production efficiency. Based on this, some embodiments of this disclosure provide a gas phase infiltration device for turbine blades. The device includes: a lower base, a preheating chamber, a transition support, a multi-stage gas distribution chamber, and an upper base, all coaxially arranged. The lower base is connected to an intake pipe, through which a mixed gas flows. The preheating chamber is located at the top of the lower base and contains aluminum particles. The mixed gas enters the preheating chamber through the lower base and reacts with the aluminum particles to form process gas. The transition support is located at the top of the preheating chamber, and the multi-stage gas distribution chamber is located at the top of the transition support and connected to the preheating chamber. The gas distribution chamber includes at least one gas distribution seat and at least one blade base. The gas distribution seat includes a distribution base and a distribution disc. The distribution disc has an array of air passage holes and is embedded inside the distribution base. The blade base is located at the top of the distribution base and has a blade mounting groove corresponding to the air passage hole array. The edge of the blade mounting groove has an array of gas distribution holes. The turbine blade is fixed through the blade mounting groove. The upper base is located at the top of the multi-stage gas distribution chamber and has an outlet hole. The process gas permeates through the multi-stage gas distribution chamber into the surface of the turbine blade and is finally discharged through the outlet hole. By coaxially stacking the components, the gas phase infiltration device can be quickly and orderly disassembled and cleaned. Placing the preheating chamber at the bottom of the multi-stage gas distribution chamber reduces the difficulty of cleaning the preheating chamber and shortens equipment downtime. At the same time, the air passage hole array on the gas distribution seat of the multi-stage gas distribution chamber and the gas distribution hole array at the edge of the blade mounting groove of the blade base can achieve uniform distribution of process gas when flowing through the turbine blade, effectively improving the consistency of the coating thickness on the blade surface. Production efficiency can be further improved by setting up multi-layer gas distribution seats and blade bases, and simultaneously performing aluminizing treatment on multiple blades. Attached Figure Description

[0016] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and elements are not necessarily drawn to scale.

[0017] Figure 1This is a schematic diagram of the structure of a vapor phase infiltration device applied to turbine blades according to some embodiments of this disclosure;

[0018] Figure 2 These are internal test images of a vapor phase infiltration device applied to turbine blades according to some embodiments of this disclosure. Detailed Implementation

[0019] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0020] It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other.

[0021] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0022] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0023] This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic diagram of the structure of a vapor phase infiltration device applied to turbine blades according to some embodiments of this disclosure. Figure 1 Includes flange 1, air guide base 2, first sleeve 3, base plate 4, protective ring 5, second sleeve 6, aluminum generator 7, transition support 8, distribution base 9, distribution plate 10, blade base 11, blade tooling 12, third sleeve 13, upper base 14, top cover 15, thermocouple 16, and air inlet pipe 17.

[0025] Figure 2 These are internal test images of a vapor phase infiltration device applied to turbine blades according to some embodiments of this disclosure.

[0026] In some embodiments, the aforementioned gas phase infiltration device applied to turbine blades may include: a lower base, a preheating chamber, a transition support 8, a multi-stage gas distribution chamber, and an upper base 14 arranged coaxially from bottom to top. Specifically, refer to... Figure 2 , Figure 2 This is a physical diagram of an internal test device for a gas phase permeation apparatus applied to turbine blades according to some embodiments of this disclosure. The lower base serves as the supporting foundation for the entire device and is connected to the intake pipe 17. The intake pipe 17 can be a metal pipe with good high-temperature resistance and corrosion resistance, allowing the flow of mixed gas. The mixed gas can be a mixture of various gases including a halogenating agent, a reducing gas, and a carrier gas. For example, hydrogen can be used as the reducing gas and carrier gas, and hydrogen chloride gas as the halogenating agent. Hydrogen and hydrogen chloride gas are mixed in a certain proportion to form a mixed gas. Simultaneously, an inert gas (such as argon) can be added as a diluent to adjust the concentration of the mixed gas. The preheating chamber is a chamber capable of reacting the mixed gas with aluminum particles. The aluminum particles can be metallic aluminum particles with a small particle size, increasing the contact area with the mixed gas and improving reaction efficiency. The preheating chamber can be located at the top of the lower base, allowing the mixed gas to enter the preheating chamber from bottom to top through the lower base, extending the residence time of the mixed gas in the preheating chamber and ensuring a complete reaction. The aforementioned mixed gas can chemically react with the aforementioned aluminum particles to generate process gas. This process gas can contain gaseous reactive species (such as aluminum trichloride), enabling an aluminizing reaction on the surface of the turbine blades to form a wear-resistant, corrosion-resistant, and high-temperature stable coating.

[0027] In some embodiments, the transition support 8 can be a structural component disposed at the top of the preheating chamber, serving to support and fix the multi-stage gas distribution chamber. The multi-stage gas distribution chamber can be a chamber structure capable of uniformly distributing the process gas to each turbine blade, providing a stable reaction environment for the aluminizing reaction between the turbine blades and the process gas. The multi-stage gas distribution chamber can be disposed at the top of the transition support 8 and connected to the preheating chamber, allowing the process gas to enter the interior of the multi-stage gas distribution chamber. The interior of the multi-stage gas distribution chamber can include at least one gas distribution seat and at least one blade base 11. The gas distribution seat can include a distribution base 9 and a distribution disk 10. The distribution base 9 can be disposed at the top of the transition support 8 and connected to the preheating chamber via a gas conduit. The gas conduit can be a pipe structure capable of introducing the process gas into the interior of the multi-stage gas distribution chamber. The aforementioned distribution disk 10 can be a flat, disc-shaped structure that can be embedded inside the distribution base 9. The distribution disk 10 may have an array of air passage holes, which can be a perforated structure allowing the process gas to pass through, achieving uniform distribution of the process gas through the evenly distributed air passage holes. For example, the air passage holes in the array can be evenly distributed along the circumference of the distribution disk 10, allowing the process gas to be evenly dispersed as it passes through. The aforementioned blade base 11 can be a structural component located at the top of the distribution base 9. The aforementioned blade base 11 may have a blade mounting groove corresponding to the air passage hole array. The blade mounting groove can be a recess on the upper surface of the blade base 11, allowing the bottom of the turbine blade to be embedded therein for turbine blade fixation. An array of air passage holes can be provided at the edge of the blade mounting groove. This array of air passage holes can be a perforated structure surrounding the blade mounting groove, allowing the process gas to pass through and be evenly distributed around the turbine blade. After passing through the aforementioned gas distribution array, the process gas can be further evenly dispersed through the aforementioned gas distribution array, making the coating formed on the turbine blade surface more uniform. To improve production efficiency, two or more layers of gas distribution seats and blade bases 11 can be set, and turbine blades can be installed in each layer of gas distribution seats and blade bases 11, thereby improving production efficiency.

[0028] In some embodiments, the upper base 14 can be a structural component disposed at the top of the multi-stage gas distribution chamber, guiding process gas out of the vapor phase infiltration device. The upper base 14 may be provided with an outlet, which can communicate with the multi-stage gas distribution chamber. After the process gas undergoes an aluminizing reaction with the turbine blades in the multi-stage gas distribution chamber to form a coating, the gas that did not participate in the aluminizing reaction can be discharged through the outlet. The contact areas of each adjacent structural component can be sealed by mutually cooperating grooves, preventing gas leakage, ensuring stable pressure inside the vapor phase infiltration device, and improving production efficiency and product quality. During installation, each structural component can be cleaned with a compressed air gun to remove any residual dust and impurities, improving the cleanliness inside the vapor phase infiltration device and reducing the impact of impurities on the aluminizing reaction.

[0029] Optionally, the lower base may include a flange 1, a gas guide base 2, a first sleeve 3, and a base plate 4. The flange 1 may be a disc-shaped structure, horizontally positioned at the bottom of the vapor phase infiltration device, providing stable support for the entire device. The gas guide base 2 may be a cylindrical structure, with one end passing through the flange 1 and connecting to the inlet pipe 17, allowing the mixed gas to smoothly enter the vapor phase infiltration device; the other end may pass through the base plate 4 and connect to the preheating chamber. A sealing gasket may be provided at the end of the gas guide base 2 connected to the inlet pipe 17 to increase airtightness and prevent leakage of the mixed gas. The first sleeve 3 may be a vertically continuous cylindrical structure, positioned at the top of the flange 1 and coaxially sleeved around the gas guide base 2, providing additional support and protection for the gas guide base 2. This allows the weight of the vapor phase infiltration device to be transferred from the first sleeve 3 to the flange 1, preventing damage to the gas guide base 2 due to stress. The aforementioned base plate 4 can be a disc-shaped structural component, horizontally placed at the top of the aforementioned first sleeve 3. The center of the aforementioned base plate 4 can have a hole structure, allowing the other end of the aforementioned lower base to pass through and connect to the aforementioned preheating chamber. The aforementioned flange 1, the aforementioned air guide base 2, the aforementioned first sleeve 3, and the aforementioned base plate 4 can together constitute the basic support structure of the aforementioned gas phase permeation device.

[0030] Optionally, the preheating chamber may include a second sleeve 6 and an aluminum generator 7. The aluminum generator 7 can be a chamber where the mixed gas and aluminum particles undergo a chemical reaction. The aluminum particles can be disposed inside the aluminum generator 7, which can be placed horizontally to ensure uniform distribution and increase the contact area between the aluminum particles and the mixed gas. The aluminum generator 7 can be nested within the second sleeve 6, which has a vertically continuous cylindrical structure to provide protection and support for the aluminum generator 7, ensuring its stability under high temperature and chemical reaction conditions. The second sleeve 6 can be positioned at the top of the base plate 4 and sealed using interlocking grooves to prevent gas leakage.

[0031] Optionally, the multi-stage gas distribution chamber further includes at least one third sleeve 13. The third sleeve 13 can be a cylindrical structure extending vertically, and can be disposed at the top of the blade base 11. The turbine blade can be disposed inside the third sleeve 13. The third sleeve 13 can prevent leakage of the process gas, allowing the process gas to concentrate on the surface of the turbine blade, thereby improving the efficiency of the aluminizing reaction and the uniformity of the formed coating. The first sleeve 3, the second sleeve 6, and the third sleeve 13 can be cylindrical structures with the same inner diameter but different heights. The specific height can be set according to the installation position and is not specifically limited here.

[0032] Optionally, the multi-stage gas distribution chamber further includes a blade fixture 12. The blade fixture 12 can be a structural component that can be embedded in the blade mounting groove. Its shape can match the bottom contour of the turbine blade, and the bottom of the turbine blade can be embedded inside the blade fixture 12 for fixation. The blade fixture 12 can firmly fix the turbine blade in the blade mounting groove. Simultaneously, the height of the blade fixture 12 can be greater than the depth of the blade mounting groove, which can elevate the turbine blade, allowing the process gas to fully contact the blade surface area requiring aluminizing, resulting in a more uniform and complete coating on the turbine blade surface.

[0033] Optionally, all structural components in the aforementioned vapor phase infiltration (VPI) device can be made of graphite. Graphite possesses excellent high-temperature resistance and thermal conductivity, maintaining stable structure and performance under high-temperature conditions. This ensures that the VPI device will not affect production efficiency and product quality due to material deformation or damage during prolonged high-temperature operation. Simultaneously, graphite exhibits good chemical stability, resisting the erosion of various chemical components in mixed gases and process gases. This reduces wear and tear on structural components caused by corrosion, extends the overall service life of the device, and lowers equipment maintenance costs and replacement frequency. Furthermore, graphite is relatively lightweight, reducing the overall weight of the VPI device, facilitating installation, relocation, and operation, and improving flexibility and convenience in the production process. Moreover, graphite is easy to process and shape, meeting the manufacturing requirements of complex shapes for various structural components in the VPI device, ensuring the precision and quality of the components, thereby further enhancing the overall performance and reliability of the VPI device.

[0034] Optionally, the aforementioned vapor phase infiltration device for turbine blades may further include a protective ring 5, a thermocouple 16, and a heating cover. The protective ring 5 can be disposed at the top of the lower base, with the preheating chamber nested within it. The protective ring 5 can be used to fix the thermocouple 16. One end of the thermocouple 16 can be inserted into the mounting hole of the protective ring 5, and the other end extends to the upper base 14, allowing it to detect the overall temperature of the vapor phase infiltration device. The heating cover can be a structure capable of covering the vapor phase infiltration device. The heating cover may contain heating wires, which can be resistance heating wires, serving as a heat source to provide heat to the vapor phase infiltration device. All structural components in the vapor phase infiltration device are made of graphite material, possessing excellent thermal conductivity, which allows for rapid transfer of heat generated by the heating wires to the interior of the vapor phase infiltration device, meeting the requirements for aluminizing reactions in a high-temperature environment. The thermocouple 16 can detect the temperature inside the heating shroud. By adjusting the power of the heating wire, the temperature inside the vapor infiltration device can be stabilized within a suitable range, thereby ensuring the smooth progress of the aluminizing reaction. A graphite protective sleeve can be fitted over the thermocouple 16. This graphite protective sleeve can be a hollow cylindrical structure that fits snugly against the thermocouple 16, effectively preventing oxidation and corrosion of the thermocouple 16 under high-temperature conditions, extending its service life, and ensuring the accuracy of temperature detection.

[0035] Optionally, the aforementioned vapor phase permeation device for turbine blades may further include a top cover 15. The top cover 15 may be a structural component located at the top of the upper base 14, capable of covering the air outlet. The top of the upper base 14 may be provided with an annular sealing groove, and the air outlet may be coaxially arranged with the annular sealing groove. Fine sand may be placed in the annular sealing groove, providing a certain filtering effect. The top cover 15 may be provided with an annular boss adapted to the annular sealing groove. The width of the annular sealing groove may be greater than the width of the annular boss, allowing the annular boss to embed into the fine sand within the annular sealing groove. After the top cover 15 is installed, the height of the fine sand may be consistent with the height of the annular sealing groove. If there is insufficient fine sand, more fine sand can be added to make it consistent with the height of the annular sealing groove. After the aluminizing reaction, the process gas will contain solid particles (such as incompletely reacted halide salts, trace amounts of slag stripped by the gas flow). These solid particles can flow with the process gas. When they pass through the vent and are discharged from the gas phase infiltration device through the fine sand between the annular boss and the annular sealing groove, the fine sand can effectively intercept most of the solid particles, preventing them from entering the subsequent exhaust system and causing blockage. If there is too little fine sand, the filtration effect will be affected. At the same time, the fine sand can also buffer and stabilize the process gas, making the gas discharge process smoother and reducing pressure fluctuations caused by gas turbulence, thus ensuring the stability of the internal pressure of the gas phase infiltration device. The flange 1 can also be provided with an exhaust port, which can be connected to an exhaust pipe. The gas filtered by the fine sand can be discharged from the exhaust port into the exhaust pipe.

[0036] In addressing the aforementioned technical problems through the adoption of technical solutions, the application scenario of this technical solution—mass vapor phase aluminizing of turbine blades—often presents the following challenges: In this scenario, multiple reaction chambers are typically required to accommodate more turbine blades, necessitating mass vapor phase aluminizing. However, the process gas must completely pass through the lower reaction chamber before entering the upper one, and it is consumed with each chamber, resulting in variations in the concentration of active species in each layer. The aluminizing reaction rate is positively correlated with the concentration of active species in the process gas, leading to differences in the coating thickness and aluminizing reaction time on the turbine blade surfaces of each layer, particularly between the first and last layers. Considering the following requirements for this application scenario: adaptability to mass vapor phase aluminizing, improved coating consistency, and increased production efficiency, we have decided to adopt the following solution:

[0037] Optionally, the blade base 11 may include an upper blade base and a lower blade base. The upper blade base may be a blade base disposed at the top of the third sleeve 13, and the lower blade base may be a blade base disposed at the bottom of the third sleeve 13. The third sleeve 13, together with the upper and lower blade bases, may constitute a vapor-phase aluminizing reaction chamber. The vapor-phase aluminizing reaction chamber may be a chamber in which the turbine blade undergoes an aluminizing reaction with the process gas. The blade mounting slot may be provided with a fixing component, which can fix the turbine blade in the blade mounting slot. For example, the fixing component may be a snap-fit ​​structure, enabling quick fixing and disassembly of the turbine blade. The upper surface of the lower blade base can be provided with the aforementioned blade mounting groove, and both the upper and lower surfaces of the upper blade base can be provided with the aforementioned blade mounting groove. This allows the turbine blades fixed in the blade mounting grooves on the lower surface of the upper blade base and the turbine blades fixed in the blade mounting grooves on the upper surface of the lower blade base to be located in the same vapor-phase aluminizing reaction chamber. Specifically, the turbine blades fixed to the lower surface of the upper blade base are placed upside down within the vapor-phase aluminizing reaction chamber, while the turbine blades fixed to the upper surface of the lower blade base are placed upright within the vapor-phase aluminizing reaction chamber. This combination of upside-down and upright placement allows the process gas, after entering the vapor-phase aluminizing reaction chamber, to perform aluminizing reactions on the turbine blades in both vertical and horizontal directions within a single chamber. The upper surface of the aforementioned upper blade base can serve as the bottom of the second vapor-phase aluminizing reaction chamber. This design reduces the number of layers required to process the same number of turbine blades, thus reducing the thickness variation of the coating formed on each turbine blade surface. For example, with four turbine blade layers, the concentration of active species decreases with each layer the process gas passes through, leading to significant differences in coating thickness and aluminizing reaction time. This is especially true between the first and fourth layers, where the difference can be substantial, potentially causing the fourth layer to fail to meet quality requirements. Because the concentration of active species decreases progressively, the concentration is lower at the fourth layer, resulting in a longer aluminizing reaction time and impacting production efficiency. This combination of inverted and upright placement addresses this issue. This method only requires two layers of vapor-phase aluminizing reaction chambers to meet production needs. After the process gas consumes some aluminum in the first vapor-phase aluminizing reaction chamber, it enters the second vapor-phase aluminizing reaction chamber. Although the concentration of active species in the process gas is reduced, the combination of inverted and upright placement allows the process gas to undergo aluminizing reactions with the turbine blades in both the upper and lower directions within the same space. This results in a relatively uniform coating thickness for the turbine blades in the second vapor-phase aluminizing reaction chamber, effectively reducing the significant coating thickness difference between the first and fourth layers and improving the overall coating quality consistency. Furthermore, the reduced concentration difference of active species and the reduced number of layers also shorten the aluminizing reaction time, increasing production efficiency.

[0038] The above-described technical solution, as an inventive point of this disclosure, solves the technical problem of "significant differences in the thickness of the coating formed on the surface of each turbine blade layer." Factors leading to significant differences in the thickness of the coating formed on the surface of each turbine blade layer are often as follows: the process gas must completely pass through the lower reaction chamber before entering the upper reaction chamber, and the process gas is consumed each time it passes through a reaction chamber, resulting in differences in the concentration of active species in the process gas of each layer. The rate of the aluminizing reaction is positively correlated with the concentration of active species in the process gas, thus leading to differences in the thickness of the coating formed on the surface of each turbine blade layer and the time required for the aluminizing reaction. Solving these factors can reduce the thickness difference of the coating formed on the surface of each turbine blade layer. To achieve this effect, the vapor-phase aluminizing device for turbine blades disclosed herein employs a combination of inverted and upright placement of the turbine blades. This allows the process gas, upon entering the vapor-phase aluminizing reaction chamber, to simultaneously aluminize the turbine blades in both the upper and lower directions. Although the concentration of the process gas decreases slightly upon entering the second layer after some active species are consumed in the first vapor-phase aluminizing reaction chamber, the simultaneous aluminizing reaction in both directions ensures a relatively uniform coating thickness for the second layer of turbine blades. This effectively reduces the concentration differences of active species caused by the gradual consumption of process gas layer by layer, thereby narrowing the gap in coating thickness between blade layers and improving the overall coating quality consistency. Furthermore, by reducing the number of reaction chamber layers, shortening the flow path of the process gas within the device, and reducing the concentration differences of the process gas, the aluminizing reaction time can be shortened, thus improving production efficiency.

[0039] In addressing the aforementioned technical problems through the adoption of technical solutions, and considering the application scenario of this technical solution—the large-scale vapor phase aluminizing of different turbine blade models—the following technical issues often arise: Turbine blades of various models differ in size and shape, typically requiring multiple molds of different specifications to secure each blade. This is particularly problematic during after-sales blade maintenance, where the variety of blade models necessitates the use of specific molds for each model during vapor phase aluminizing, leading to high mold management complexity and manufacturing costs. To address the following requirements for this application scenario: adaptability to different blade models, reduced mold costs, and reduced mold management complexity, we have decided to adopt the following solution:

[0040] Optionally, the aforementioned fixing components can be made of graphite material, capable of withstanding high-temperature environments, ensuring they will not deform or be damaged due to high temperatures during the vapor-phase aluminizing process, thereby guaranteeing the stability of fixing different types of turbine blades. The aforementioned fixing components may include a fixing clamp and a moving clamp. The fixing clamp and the moving clamp can be structural components located at opposite ends of the blade mounting slot, used to accommodate different types of turbine blades and fix the turbine blades within the blade mounting slot. The fixing clamp may include a vertically arranged fixing bracket and a horizontally arranged clamping block, and the moving clamp may include a vertically arranged moving bracket and the horizontally arranged clamping block. The fixing bracket and the moving bracket can be vertically plate-shaped structural components of the same shape, and can be arranged parallel to each other at both ends of the blade mounting slot, conforming to the bottom contour of the turbine blade and providing stable support. Both the fixed bracket and the movable bracket described above can be vertically equipped with guide rails. These guide rails can be grooves inside the fixed bracket and the movable bracket, allowing one end of the clamping block to be embedded within them and moving along the vertically arranged guide rails. This enables the clamping of turbine blades of different models and sizes, thus firmly clamping the turbine blades within the blade mounting slots. The clamping block can be a rod-shaped structure with a first threaded hole at one end. Both the fixed bracket and the movable bracket can have a vertically arranged first threaded rod penetrating the guide rail embedded inside. This first threaded rod can be a rod-shaped structure made of graphite material and can be embedded from the ends of the fixed bracket and the movable bracket, respectively. The top of the first threaded rod can have a groove for easy rotation using tools, such as a flathead screwdriver, a Phillips head screwdriver, or an internal hexagonal slot, allowing rotation using a corresponding tool (such as a flathead screwdriver, a Phillips head screwdriver, or an internal hexagonal wrench). One end of the clamping block with the first threaded hole can be inserted into the guide rail and engage with the first threaded rod. A tool can be used to insert into the groove at the top of the first threaded rod to rotate it, thereby moving the clamping block along the guide rail. The bottom of the movable bracket may have a horizontally arranged second threaded hole, and the interior of the blade base may have a horizontally arranged second threaded rod embedded therein. The second threaded rod can be inserted along the side of the blade base and engage with the second threaded hole at the bottom of the movable bracket. The top of the second threaded rod may have the same groove as the first threaded rod. A tool can be used to rotate the second threaded rod to move the movable caliper horizontally. The distance between the fixed caliper and the movable caliper can be flexibly adjusted according to the size differences of different turbine blade models to achieve clamping.Specifically, when it is necessary to fix the turbine blade, the turbine blade can be first attached to the fixing bracket, and then the moving caliper can be moved horizontally towards the fixing caliper by rotating the second threaded rod to shorten the distance between the two to match the size of the turbine blade. Then, the clamping block can be moved downward along the guide slide rail by rotating the first threaded rod to firmly clamp the turbine blade and achieve fixation.

[0041] The above-described technical solution, as an inventive point of this disclosure, solves the technical problem of "large quantities of turbine blades of different models differing in size and shape, typically requiring multiple molds of different specifications to fix the corresponding turbine blades. This is especially problematic during after-sales blade maintenance, where multiple blade models exist, and each model requires a corresponding mold for fixation during vapor phase aluminizing, leading to high costs." The factors contributing to high costs are often as follows: large quantities of turbine blades of different models differing in size and shape, typically requiring multiple molds of different specifications to fix the corresponding turbine blades. This is especially problematic during after-sales blade maintenance, where multiple blade models exist, and each model requires a corresponding mold for fixation during vapor phase aluminizing, leading to high costs. Solving these factors can reduce costs. To achieve this effect, the gas phase infiltration device for turbine blades disclosed herein employs an adjustable fixing component made of graphite material to adapt to high-temperature environments. By using a fixed clamp and a movable clamp, it achieves flexible fixing of turbine blades of different models and sizes. This not only reduces the cost of equipping multiple molds due to the variety of blade models, but also improves the versatility and efficiency of the molds. Especially in multi-model production scenarios such as blade after-sales maintenance, it significantly reduces production costs and mold management complexity.

[0042] In addressing the aforementioned technical problems through the adoption of technical solutions, and considering the application scenario of this technical solution—aluminizing turbine blades for aerospace engines—the following technical challenges often arise: Aerospace engine turbine blades require extremely high uniformity and quality in the aluminizing process. Furthermore, turbine blades possess complex three-dimensional aerodynamic surfaces. The process gas enters the reaction chamber only through vertical perforations, resulting in low gas flowability and difficulty in ensuring uniform coverage of every part of the blade. This leads to uneven coating thickness, consequently resulting in lower blade performance and service life. To meet the following requirements for this application scenario: adaptability to complex curved blade processing, improved gas flowability, and improved coating uniformity, we have decided to adopt the following solution:

[0043] Optionally, the distribution disk 10 can be divided into a central area, an intermediate area, and an outer area distributed concentrically. These three areas can be equally spaced, and the array of air passages can be uniformly distributed within them to facilitate the diffusion of the process gas. The apertures of the air passages in the central, intermediate, and outer areas can increase sequentially, and the apertures within the same area are identical. This allows the process gas passing through the array of air passages to form a three-dimensional swirling flow field rotating around the central axis of the distribution disk 10, resulting in a more uniform concentration distribution of active species in the process gas. The axes of the air passages in the central area can be perpendicular to the disk surface of the distribution disk 10, and the apertures can be set relatively small. This can act as a throttling mechanism, effectively damping potential airflow fluctuations from the preheating chamber, converting part of the kinetic energy of the process gas into pressure energy, and increasing the flow rate of the process gas passing through the intermediate and outer areas. The axis of each of the above-mentioned air passages located in the intermediate zone can be set at a first angle with the vertical axis of the distribution plate 10. The first angle can be between 30° and 45°, which can make the airflow obliquely ejected and initially form a vortex. If the first angle is less than 30°, the vortex effect is weak and it is difficult to effectively drive the process gas to form a three-dimensional vortex field. If the first angle is greater than 45°, the angle of the airflow obliquely ejected is too large, which affects the stability and coverage of the airflow in the outer zone. The axis of the air passage located in the outer perimeter can form a second angle with the vertical axis of the distribution disk 10. This second angle can be between 60° and 75°, and can be greater than the first angle. This can further enhance the swirling intensity and coverage. If the second angle is less than 60°, the rotational power of the outer airflow is insufficient, making it difficult to coordinate with the airflow in the middle region to form a stable three-dimensional swirling flow. If the second angle is greater than 75°, the airflow is prone to deflection against the wall, reducing its coverage of the blade surface. By using a progressive spiral path to wrap around the blade surface, the process gas can be prevented from concentrating in the central area of ​​the distribution disk 10, thus avoiding uneven distribution. Simultaneously, a larger aperture ensures rapid diffusion of the process gas, covering a wider area. The air distribution array can be distributed around the edge of the blade mounting slot, allowing the process gas to be evenly distributed around the turbine blade, which is beneficial for forming a uniform coating. Each air distribution hole in the array can be vertically arranged, and each air distribution hole can include an inlet section, a middle section, and an outlet section. Both the aforementioned inlet section and the aforementioned outlet section may be provided with axially symmetrical conical guide surfaces. The conical guide surface provided in the aforementioned inlet section can reduce local turbulence and pressure loss, and can reduce sudden contraction, eddies and energy loss caused by right-angle or acute-angle inlets, so that the process gas enters the aforementioned gas distribution holes in a more orderly and stable state.The aforementioned intermediate section can be a cylindrical surface with a uniform cross-section, which can maintain the stable flow of the process gas within the distribution holes and reduce the possibility of sudden velocity changes and turbulence caused by cross-sectional variations. The conical guide surface provided in the aforementioned outlet section can reduce the flow velocity of the process gas, reduce the direct impact of the process gas on the turbine blade surface, prevent local coatings from being too thick or too thin, and at the same time, promote the diffusion of the process gas, forming a uniform airflow. This allows the process gas to more evenly cover the complex three-dimensional aerodynamic surface of the turbine blade, ensuring the uniformity of the coating thickness. The uniform airflow distribution also helps to improve the efficiency of the aluminizing reaction, allowing the active species to more fully contact and react with the turbine blade surface, which can shorten processing time, reduce energy consumption, and improve production efficiency. The inner walls of both the aforementioned through-hole array and the aforementioned distribution hole array can be smoothed to reduce turbulence and resistance when the process gas passes through, further improving the stability and uniformity of the gas flow.

[0044] The above-described technical solution, as an inventive point of this disclosure, solves the technical problem of "low fluidity of process gas, making it difficult to ensure that the process gas can uniformly cover every part of the blade, resulting in uneven coating thickness and consequently lower blade performance and service life." Factors leading to lower blade performance and service life are often as follows: turbine blades of aerospace engines have extremely high requirements for the uniformity and quality of aluminizing treatment, and turbine blades have complex three-dimensional aerodynamic surfaces. Process gas enters the reaction chamber only through vertical perforated structures, resulting in low fluidity and difficulty in ensuring uniform coverage of every part of the blade, leading to uneven coating thickness and consequently lower blade performance and service life. Solving these factors can improve blade performance and extend its service life. To achieve this effect, the vapor phase infiltration device for turbine blades disclosed in this disclosure differentiates the design of the gas distribution holes in different areas of the distribution disk. By successively increasing the diameter of the gas passage holes in the central, intermediate, and peripheral areas and setting specific angles, a three-dimensional swirling flow field rotating around the central axis of the distribution disk is constructed, effectively improving the uniformity of the concentration distribution of active species in the process gas. Meanwhile, the inlet, middle and outlet sections of each gas distribution hole in the gas distribution hole array are carefully designed, which not only reduces local turbulence and pressure loss, but also allows the process gas to enter and uniformly cover the complex three-dimensional aerodynamic surface of the turbine blade in a stable and orderly state, significantly improving the efficiency of the aluminizing reaction. This allows the active species to come into more full contact with the blade surface and react, thereby shortening the processing time, reducing energy consumption, and improving production efficiency. Ultimately, this achieves a significant improvement in the uniformity of the blade coating thickness and the blade performance and service life.

[0045] The above-described embodiments of this disclosure have the following beneficial effects: the vapor phase infiltration device applied to turbine blades according to some embodiments of this disclosure can improve production efficiency. Specifically, the reason for the low production efficiency is that the active gas is difficult to distribute evenly when flowing through the stacked blades, resulting in poor consistency of the coating thickness on the blade surface. At the same time, the slag generated in the reaction vessel is distributed throughout the inner cavity of the vessel, and the device must be completely disassembled for subsequent cleaning, which is cumbersome and time-consuming, resulting in long equipment downtime and low production efficiency. Based on this, some embodiments of this disclosure provide a gas phase infiltration device for turbine blades. The device includes: a lower base, a preheating chamber, a transition support, a multi-stage gas distribution chamber, and an upper base, all coaxially arranged. The lower base is connected to an intake pipe, through which a mixed gas flows. The preheating chamber is located at the top of the lower base and contains aluminum particles. The mixed gas enters the preheating chamber through the lower base and reacts with the aluminum particles to form process gas. The transition support is located at the top of the preheating chamber, and the multi-stage gas distribution chamber is located at the top of the transition support and connected to the preheating chamber. The gas distribution chamber includes at least one gas distribution seat and at least one blade base. The gas distribution seat includes a distribution base and a distribution disc. The distribution disc has an array of air passage holes and is embedded inside the distribution base. The blade base is located at the top of the distribution base and has a blade mounting groove corresponding to the air passage hole array. The edge of the blade mounting groove has an array of gas distribution holes. The turbine blade is fixed through the blade mounting groove. The upper base is located at the top of the multi-stage gas distribution chamber and has an outlet hole. The process gas permeates through the multi-stage gas distribution chamber into the surface of the turbine blade and is finally discharged through the outlet hole. By coaxially stacking the components, the gas phase infiltration device can be quickly and orderly disassembled and cleaned. Placing the preheating chamber at the bottom of the multi-stage gas distribution chamber reduces the difficulty of cleaning the preheating chamber and shortens equipment downtime. At the same time, the air passage hole array on the gas distribution seat of the multi-stage gas distribution chamber and the gas distribution hole array at the edge of the blade mounting groove of the blade base can achieve uniform distribution of process gas when flowing through the turbine blade, effectively improving the consistency of the coating thickness on the blade surface. Production efficiency can be further improved by setting up multi-layer gas distribution seats and blade bases, and simultaneously performing aluminizing treatment on multiple blades.

[0046] The above description is merely a selection of preferred embodiments of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this disclosure.

Claims

1. A vapor-phase percolation device for turbine blades, characterized in that, include: The lower base, preheating chamber, transition support, multi-stage gas distribution chamber, and upper base are coaxially arranged. The lower base is connected to an air intake pipe, and a mixed gas flows inside the air intake pipe; The preheating chamber is located at the top of the lower base. The preheating chamber contains aluminum particles. The mixed gas enters the preheating chamber through the lower base and reacts with the aluminum particles to form process gas. The transition support is located at the top of the preheating chamber, and the multi-stage gas distribution chamber is located at the top of the transition support and connected to the preheating chamber. The interior of the multi-stage gas distribution chamber includes at least one gas distribution seat and at least one blade base. The gas distribution seat includes a distribution base and a distribution disk. The distribution disk is provided with an array of air passage holes. The distribution disk is embedded inside the distribution base. The blade base is located at the top of the distribution base and is provided with a blade mounting groove corresponding to the array of air passage holes. The edge of the blade mounting groove is provided with an array of air distribution holes. The turbine blade is fixed through the blade mounting groove. The upper base is located at the top of the multi-stage gas distribution chamber. The upper base is provided with an exhaust port. The process gas permeates into the surface of the turbine blade through the multi-stage gas distribution chamber and is finally discharged through the exhaust port.

2. The vapor phase infiltration device for turbine blades according to claim 1, characterized in that, The lower base includes a flange, an air guide base, a first sleeve, and a base plate; The flange is horizontally arranged, one end of the air guide base passes through the flange and is connected to the air inlet pipe, the first sleeve is arranged on the flange and coaxially sleeved on the outside of the air guide base, and the base plate is arranged on the top of the first sleeve. The other end of the air guide base passes through the base plate and is connected to the preheating chamber.

3. The vapor phase infiltration device for turbine blades according to claim 1, characterized in that, The preheating chamber includes a second sleeve and an aluminum generator, wherein the aluminum generator is nested inside the second sleeve; The aluminum granules are disposed inside the aluminum generator.

4. The vapor phase infiltration device for turbine blades according to claim 1, characterized in that, The multi-stage gas distribution chamber also includes at least one third sleeve; The third sleeve is disposed at the top of the blade base, and the turbine blade is disposed inside the third sleeve.

5. The vapor phase infiltration device for turbine blades according to claim 4, characterized in that, The multi-stage gas distribution chamber also includes a blade fixture, which can be embedded in the blade mounting slot. The bottom of the turbine blade is embedded inside the blade tooling for fixation.

6. The vapor phase infiltration device for turbine blades according to claim 1, characterized in that, All structural components in the vapor phase infiltration device are made of graphite material.

7. The vapor phase infiltration device for turbine blades according to claim 1, characterized in that, The vapor phase infiltration device applied to turbine blades also includes a protective ring, a thermocouple, and a heating shroud; The protective ring is disposed at the top of the lower base, and the preheating chamber is nested inside the protective ring; One end of the thermocouple is embedded in the protective ring, and the other end extends to the upper base; The heating cover covers the vapor phase infiltration device, and the heating cover can provide a heat source for the vapor phase infiltration device. The thermocouple can detect the temperature inside the heating cover.

8. The vapor phase infiltration device for turbine blades according to claim 1, characterized in that, The vapor phase infiltration device applied to turbine blades also includes a top cover; The top of the upper base is provided with an annular sealing groove, the air outlet is coaxially arranged with the annular sealing groove, and fine sand is placed in the annular sealing groove. The top cover is provided with an annular boss that matches the annular sealing groove. The width of the annular sealing groove is greater than the width of the annular boss, and the annular boss can be embedded in the fine sand in the annular sealing groove. After the top cover is installed, the height of the fine sand is consistent with the height of the annular sealing groove; The process gas passes through the outlet and is discharged through the fine sand between the annular boss and the annular sealing groove.

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