Method for increasing the service life of a centrifugal compressor impeller

Abstract

The application discloses a method for prolonging the service life of a centrifugal air compressor impeller, which comprises the following steps: disassembling and cleaning a stainless steel base impeller, placing the stainless steel base impeller and copper alloy powder material in a steel plate mold, placing the steel plate mold in a high-temperature furnace and carrying out high-temperature heating and heat preservation, so that the copper alloy powder material is fully cladded on the surface of the stainless steel base impeller and the cladding strength is ensured, taking out the steel plate mold from the high-temperature furnace and carrying out water cooling, taking out the stainless steel base impeller cladded with the copper alloy powder material from the steel plate mold, and carrying out finish machining according to an impeller drawing, so as to obtain the stainless steel base impeller with the copper alloy coating on the blade tooth top surface. The method clads the copper alloy on the blade tooth top surface of the steel structure base of the impeller, retains the performance of the stainless steel base impeller, increases the wear resistance and corrosion resistance of the surface copper alloy, significantly prolongs the service life of the impeller, and reduces the cost of spare parts and maintenance.

Description

Technical Field

[0001] This invention relates to the field of equipment maintenance technology, and in particular to a method for improving the service life of centrifugal air compressor impellers. Background Technology

[0002] Compressed air is widely used in steel enterprises as a power source for equipment and a driving air source for pneumatic actuators. Insufficient compressed air supply can lead to main line shutdowns and significant economic losses. Centrifugal air compressors, as crucial equipment for compressed air production, require stable and safe operation, and the impeller is a key component. During operation, centrifugal air compressors cannot completely filter dust from the air, inevitably allowing water vapor and some dust to enter the equipment. Water released from the air corrodes the impeller, while dust further causes wear. When impeller wear reaches a certain level, it can lead to equipment vibration and even blade breakage, causing equipment shutdown or more serious consequences. The quality of the impeller determines the reliability of the equipment; a more reliable impeller significantly improves operational stability and safety. Currently, large air compressor stations in domestic steel enterprises generally use foreign brands such as Ingersoll Rand, Samsung, and Sullair, relying heavily on imported parts for replacement, which significantly increases maintenance costs.

[0003] In the steel industry, centrifugal air compressors are typically distributed across various centralized air compressor stations, such as blast furnaces, sintering plants, and coking plants. Each station usually has only one or two backup units. Under extreme weather conditions such as high temperatures, the failure rate of the equipment itself increases, making the backup units particularly vulnerable. If air consumption increases and an air compressor malfunctions, insufficient backup units or startup failures may cause the main production line to shut down, resulting in significant economic losses. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for improving the service life of centrifugal air compressor impellers. This method involves cladding a copper alloy onto the top surface of the impeller blade teeth in the steel structure matrix of the impeller, which not only retains the performance of the stainless steel matrix impeller, but also increases the wear resistance and corrosion resistance of the surface copper alloy, significantly improving the service life of the impeller and reducing spare parts and maintenance costs.

[0005] To solve the above-mentioned technical problems, the method of the present invention for improving the service life of centrifugal air compressor impeller includes the following steps: Step 1: Prepare a stainless steel base impeller blank, or disassemble and clean an existing stainless steel base impeller. Step 2: Roughly machine the stainless steel base impeller workpiece, machine the blade tooth tip surface to -3mm, retain finishing allowance for other parts, and apply an anti-oxidation layer to the blade tooth tip surface; Step 3: Prepare copper alloy powder material; Step 4: Make a steel mold according to the shape of the stainless steel base impeller. The small end of the steel mold is made of welded steel plate, and the steel plate is provided with vent holes. Step 5: Invert the steel plate mold and place the stainless steel base impeller workpiece and copper alloy powder material inside the steel plate mold. The large end of the steel plate mold is sealed by welding steel plates. Step Six: Place the steel plate mold with the large end facing down in the high-temperature furnace, and gradually heat it to 1200°C over 2 hours. o C. The steel plate mold is kept at a high temperature in the furnace for 30 minutes, so that the copper alloy material gradually dissolves into liquid at a high temperature and is fully melted and coated on the surface of the stainless steel base impeller workpiece in the form of liquid metal. Step 7: Remove the steel plate mold from the high-temperature furnace and place it on a circulating cooling water container to gradually and slowly cool the stainless steel base impeller workpiece inside the steel plate mold to room temperature from the inside out; Step 8: Machining removes the steel plate mold, takes out the stainless steel base impeller workpiece with copper alloy fused to the blade tooth tip surface, and performs precision machining on the stainless steel base impeller workpiece according to the drawing to obtain a stainless steel base impeller with copper alloy coating on the blade tooth tip surface.

[0006] Furthermore, the diameter of the vent hole in the small end of the steel mold is 3mm.

[0007] Furthermore, after the stainless steel base impeller workpiece is removed from the steel plate mold, it undergoes ultrasonic and liquid penetration non-destructive testing to avoid defects or inhomogeneities in the workpiece.

[0008] The present invention improves the service life of centrifugal air compressor impellers by employing the aforementioned technical solution. Specifically, the method involves disassembling and cleaning the stainless steel impeller, placing the stainless steel impeller and copper alloy powder material inside a steel plate mold, placing the mold in a high-temperature furnace for high-temperature heating and heat preservation, ensuring the copper alloy powder material is fully fused onto the surface of the stainless steel impeller, guaranteeing fusion strength, removing the mold from the furnace, and then water-cooling it. The copper alloy powder-coated stainless steel impeller is then removed from the mold and precision-machined according to the impeller drawings to obtain a stainless steel impeller with a copper alloy coating on the blade tooth tip surface. This method, by fusing copper alloy onto the steel structure of the impeller and then onto the blade tooth tip surface, retains the performance of the stainless steel impeller while increasing the wear resistance and corrosion resistance of the surface copper alloy, significantly improving the impeller's service life and reducing spare parts and maintenance costs. Attached Figure Description

[0009] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of a stainless steel-based impeller obtained using this method. Detailed Implementation

[0010] Implementation, for example Figure 1 As shown, the method of the present invention for improving the service life of a centrifugal air compressor impeller includes the following steps: Step 1: Prepare a stainless steel base impeller blank, or disassemble and clean an existing stainless steel base impeller. Step 2: Roughly machine the stainless steel base impeller 1 workpiece, machine the surface of the blade tooth tip 2 to -3mm, retain the finishing allowance for other parts, and apply an anti-oxidation layer to the surface of the blade tooth tip 2. Step 3: Prepare copper alloy (CuZn) 12 Ni2) powder materials; Step 4: Make a steel mold according to the shape of the stainless steel base impeller. The small end of the steel mold is made of welded steel plate, and the steel plate is provided with vent holes. Step 5: Invert the steel plate mold and place the stainless steel base impeller workpiece and copper alloy powder material inside the steel plate mold. The large end of the steel plate mold is sealed by welding steel plates. Step Six: Place the steel plate mold with the large end facing down in the high-temperature furnace, and gradually heat it to 1200°C over 2 hours. o C. The steel plate mold is kept at a high temperature in the furnace for 30 minutes, so that the copper alloy material gradually dissolves into liquid at a high temperature and is fully melted and coated on the surface of the stainless steel base impeller workpiece in the form of liquid metal. Step 7: Remove the steel plate mold from the high-temperature furnace and place it on a circulating cooling water container to gradually and slowly cool the stainless steel base impeller workpiece inside the steel plate mold to room temperature from the inside out; Step 8: Machining removes the steel plate mold, takes out the stainless steel base impeller workpiece with copper alloy fused to the blade tooth tip surface, and performs precision machining on the stainless steel base impeller workpiece according to the drawing to obtain a stainless steel base impeller with copper alloy coating on the blade tooth tip surface.

[0011] Preferably, the diameter of the vent hole in the small end of the steel mold is 3mm.

[0012] Preferably, after the stainless steel base impeller workpiece is removed from the steel plate mold, it is subjected to ultrasonic and liquid penetrant non-destructive testing to avoid defects or inhomogeneities in the workpiece.

[0013] Stainless steel, with its excellent corrosion resistance and high-temperature resistance, is a commonly used material for manufacturing centrifugal air compressor impellers, and stainless steel-based impellers also have a relatively long service life. This method, based on the impeller's metal substrate, employs a new technology to clad a copper alloy onto the outer surface of the impeller to create a bimetallic impeller. Compared to traditional stainless steel-based impellers, the bimetallic impeller mainly involves an additional metal cladding process. This special cladding process ensures high bonding strength and consistency between the two different bimetallic surfaces, making it easier to manufacture. Therefore, this bimetallic impeller not only retains the structural characteristics of the original substrate material, but the low-friction characteristics of the outer copper alloy and steel metal provide excellent surface wear resistance, effectively preventing serious mechanical damage caused by friction with contaminant particles and the air compressor casing. Furthermore, the friction between steel and copper is superior to that between steel and steel, reducing risks while better protecting the main core components around the impeller, extending their service life, and improving the safety and reliability of the equipment.

[0014] The bimetallic impeller obtained using this method, when the unit is running, benefits from the copper alloy on the blade tooth tip surface, which improves the stability of the equipment operation and reduces corrosion and wear caused by moisture in the air, further extending the impeller's service life. When problems occur during unit operation, the copper alloy on the blade tooth tip surface rubs against the air compressor volute, thus avoiding hard friction between the stainless steel-based impeller and the volute, preventing damage to the volute and also avoiding other accidents caused by sparks generated by hard friction.

Claims

1. A method for improving the service life of a centrifugal air compressor impeller, characterized in that... This method includes the following steps: Step 1: Prepare a stainless steel base impeller blank, or disassemble and clean an existing stainless steel base impeller. Step 2: Roughly machine the stainless steel base impeller workpiece, machine the blade tooth tip surface to -3mm, retain finishing allowance for other parts, and apply an anti-oxidation layer to the blade tooth tip surface; Step 3: Prepare copper alloy powder material; Step 4: Make a steel mold according to the shape of the stainless steel base impeller. The small end of the steel mold is made of welded steel plate, and the steel plate is provided with vent holes. Step 5: Invert the steel mold and place the stainless steel base impeller workpiece and copper alloy powder material inside the steel mold. The large end of the steel mold is sealed by welding steel plates. Step Six: Place the steel mold, large end down, in the high-temperature furnace. Gradually heat the furnace to 1200°C over 2 hours. o C. The steel mold is kept at a high temperature in the furnace for 30 minutes, so that the copper alloy material gradually dissolves into liquid at a high temperature and is fully melted and coated on the surface of the stainless steel base impeller workpiece in the form of liquid metal. Step 7: Remove the steel mold from the high-temperature furnace and place it on a circulating cooling water container to gradually and slowly cool the stainless steel base impeller workpiece inside the steel mold to room temperature from the inside out. Step 8: Remove the steel mold by machining, take out the stainless steel base impeller workpiece with copper alloy coating on the blade tooth tip surface, and perform precision machining on the stainless steel base impeller workpiece according to the drawing to obtain a stainless steel base impeller with copper alloy coating on the blade tooth tip surface.

2. The method for improving the service life of a centrifugal air compressor impeller according to claim 1, characterized in that: The diameter of the vent hole in the small end of the steel mold is 3mm.

3. The method for improving the service life of a centrifugal air compressor impeller according to claim 1, characterized in that: After the stainless steel impeller workpiece is removed from the steel mold, it undergoes ultrasonic and liquid penetrant non-destructive testing to avoid defects or inconsistencies in the workpiece.

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