A welded volute

Abstract

The application discloses a welded volute, which comprises a first side plate, a second side plate, an inner circular surface, an outer circular surface and a guide vane; one end of the outer circular surface is connected with the first side plate, and the other end is connected with the second side plate; the first side plate and the second side plate are both provided with a circular opening; the inner circular surface is in the shape of a circular truncated cone, and one end is connected with the circular opening of the second side plate; a plurality of guide vanes are uniformly arranged on the periphery of the inner circular surface in a circumferential direction; the guide vanes are in the shape of a circular arc, one end of the outer wall of the guide vanes is fixedly connected with the second side plate, and the other end of the outer wall is fixedly connected with the inner circular surface; the outer circular surface, the inner circular surface, the first side plate and the second side plate form an annular inner cavity and an air inlet, and the air inlet is communicated with the annular inner cavity. The volute can be quickly and efficiently processed by using simple plate materials and tubular materials, and in the processing process, a plurality of steel plates are not needed to be welded to form an arc surface, the welds in the flow channel are few, the inner surface of the flow channel is smoother, the processing efficiency is high, and the cost is low.

Description

Technical Field

[0001] This invention belongs to the field of volute technology, and specifically relates to a welded volute. Background Technology

[0002] When performing performance tests on existing bladed compressors (compressors, turbines), the power of the rotating shaft needs to be measured. Often, the inlet and outlet directions of the bladed compressor are perpendicular, while the outlet direction is coaxial with the rotating shaft. This prevents axial air intake, forcing circumferential intake. However, bladed compressors have specific requirements for inlet flow rate, pressure, and temperature. In engineering practice, air is typically supplied through pipelines. Therefore, a device is needed to convert the unidirectional pipeline supply to circumferential intake, thus meeting the inlet requirements of the bladed compressor. Simultaneously, to ensure the uniformity of the inlet airflow field, the outflow velocity in each circumferential direction should be approximately uniform.

[0003] In existing technologies, cast volutes are typically used to address the aforementioned problems. Cast volutes are mostly produced through sand casting, integrally formed, and then the mating surfaces for mechanical connection with the impeller are precision machined. To ensure that the outflow velocity in all circumferential directions is approximately uniform, the cross-sectional area of ​​the volute is often larger where it connects to the pipe and smaller where it is farther away, resulting in high casting costs, high scrap rates, and long production cycles. To ensure strength, existing cast volutes often have thicker walls, and non-destructive testing is required before shipment, further increasing production costs.

[0004] In the existing technology, the inner cavity of the cast volute is difficult to process in the later stage. Therefore, the inner cavity of the finished product is generally the cast surface, which makes it difficult to guarantee the roughness of the inner cavity. This results in high flow resistance when the volute is working, large pressure loss in the whole system, and energy waste.

[0005] In the existing technology, the inner cavity of the cast volute is difficult to process in the later stage, so the inner cavity size of the finished product can only be guaranteed by the sand mold. This makes it difficult to guarantee the dimensional tolerance and form and position tolerance of the inner cavity, resulting in a large difference between the outlet flow field and the design theoretical value when the volute is working, and thus a high degree of non-uniformity of the outlet flow field.

[0006] In existing technologies, the two flanges connecting the volute and the impeller are often not on the same plane. This necessitates that the distance between the two flanges of the volute and the impeller be kept extremely consistent with that of the two flanges of the impeller. Otherwise, one flange's mating surface may be tightly pressed while the other flange's mating surface still has a gap, leading to air leakage during operation. Therefore, this structure places extremely high demands on the machining precision of both the volute and the impeller, making machining extremely difficult. Furthermore, when the sealing surface of the volute wears down after prolonged use, repair becomes extremely difficult. Summary of the Invention

[0007] To address the above problems, the present invention discloses a welded volute, comprising: a first side plate, a second side plate, an inner circular surface, an outer circular surface, and a guide vane;

[0008] One end of the outer circular surface is connected to the first side plate, and the other end is connected to the second side plate;

[0009] Both the first and second side plates are provided with circular openings;

[0010] The inner circular surface is shaped like a frustum, and one end is connected to the circular opening of the second side plate;

[0011] Multiple guide vanes are evenly arranged around the outer periphery of the inner circular surface;

[0012] The guide vane is arc-shaped, with one end of the outer wall of the guide vane fixedly connected to the second side plate, and the other end of the outer wall fixedly connected to the inner circular surface;

[0013] An annular cavity and an airflow inlet are formed between the outer circular surface, the inner circular surface, the first side plate, and the second side plate, and the airflow inlet is connected to the annular cavity.

[0014] Furthermore, a first flange is provided at the circular opening of the first side plate;

[0015] A second flange is provided at the other end of the inner circular surface;

[0016] The inner diameter of the first flange is larger than the outer diameter of the second flange, forming an annular airflow outlet between them;

[0017] The first flange and the second flange are located on the same plane.

[0018] Furthermore, the wall thickness of the guide plate does not exceed the wall thickness of the inner circular surface and the wall thickness of the second side plate.

[0019] Furthermore, the radius of the arc of the guide plate is 1 / 4 to 1 / 2 times the distance between the first side plate and the second side plate.

[0020] Furthermore, the included angle between the inner circular surface and the second side plate is in the range of 120° to 135°.

[0021] Furthermore, it also includes: internal reinforcing plates;

[0022] The inner reinforcing plate is boat-shaped and is located at the airflow inlet, parallel to the airflow direction.

[0023] The front and rear edges of the inner reinforcing plate form acute angles, with the angle not exceeding 20°.

[0024] Both ends of the inner reinforcing plate are rounded, with a rounding radius of not less than 2.5mm.

[0025] Furthermore, the center of the outer circular surface, the center of the top circle of the inner circular surface, and the central axis of the inner reinforcing plate are located on the same straight line;

[0026] When 0.25 < r / R < 0.65, the eccentricity between the center of the outer circle and the center of the top circle of the inner circle is in the range of 0.65 * (R). 2 -r 2 ) 0.5 -0.5r~0.8*(R 2 -r 2 ) 0.5 -0.45r;

[0027] Where r is the radius of the top circle of the inner circle; R is the radius of the outer circle.

[0028] Furthermore, it also includes: external reinforcing plates;

[0029] Several external reinforcing plates are fixedly installed on the outer circular sidewall;

[0030] The outer reinforcing plate is provided with several lifting holes.

[0031] Furthermore, it also includes: mounting plates;

[0032] Several mounting plates are fixedly installed on the outer circular sidewall;

[0033] The mounting plate is provided with several mounting holes.

[0034] Furthermore, it also includes: drain holes;

[0035] The drain hole is located on the outer circular surface.

[0036] Compared with the prior art, the embodiments of the present invention have at least the following advantages:

[0037] 1. This invention can quickly and efficiently process volutes using simple sheet metal and pipe profiles. During the processing, there is no need to weld multiple steel plates together to form an arc surface. There are fewer welds in the flow channel, the inner surface of the flow channel is smoother, the processing efficiency is high, and the cost is low.

[0038] 2. The present invention designs the two flange edges of the volute to be on the same plane, which can reduce the number of processing steps during the manufacturing process and better ensure the tightness of the fit between the two flange edges of the volute and the object, and will not result in a situation where one flange edge is tightened with bolts while the other flange edge still leaks air.

[0039] 3. The present invention adopts an eccentric design of the inner and outer circles of the volute, so that as the airflow decreases in the volute, the corresponding flow cross section gradually shrinks, ensuring that the airflow velocity does not change significantly and reducing the pressure loss caused by sudden changes in flow velocity.

[0040] 4. The inner circular surface of the volute of this invention is frustum-shaped, which can better guide airflow, reduce pressure loss, and at the same time leave more operating space for mechanical assembly and disassembly of the impeller;

[0041] 5. The present invention has a built-in guide plate and an inner reinforcing plate, which can rectify the flow field inside the volute, reduce the pressure loss of the volute, and improve the overall rigidity of the volute.

[0042] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A schematic diagram of the structure of a welded volute according to an embodiment of the present invention is shown;

[0045] Figure 2 A schematic diagram of the internal structure of the welded volute according to an embodiment of the present invention is shown;

[0046] Figure 3 A cross-sectional view of the mechanical assembly of the welded volute and impeller according to an embodiment of the present invention is shown;

[0047] Figure 4 A schematic diagram of the structure of the inner reinforcing plate according to an embodiment of the present invention is shown;

[0048] Figure 5 A schematic diagram of the eccentricity of the welded volute according to an embodiment of the present invention is shown.

[0049] Reference numerals: 1. Airflow inlet; 2. Airflow outlet; 3. First side plate; 4. Second side plate; 5. Inner reinforcing plate; 6. Outer reinforcing plate; 7. Inner circular surface; 8. Outer circular surface; 9. Mounting plate; 10. First flange; 11. Second flange; 12. Guide vane; 13. Drain hole; 14. Impeller mechanism; 15. Welded volute support. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0051] Figure 1 A schematic diagram of the structure of a welded volute according to an embodiment of the present invention is shown. Figure 1 As shown, the present invention proposes a welded volute, comprising: a first side plate 3, a second side plate 4, an inner circular surface 7, an outer circular surface 8, and a guide plate 12;

[0052] One end of the outer circular surface 8 is fixedly connected to the first side plate 3, and the other end is fixedly connected to the second side plate 4;

[0053] Both the first side plate 3 and the second side plate 4 are provided with corresponding circular openings;

[0054] The inner circular surface 7 is in the shape of a frustum, and one end (the bottom circle of the inner circular surface 7) is fixedly connected to the circular opening of the second side plate 4;

[0055] Multiple guide vanes 12 are evenly arranged around the outer periphery of the inner circular surface 7;

[0056] The guide vane 12 is arc-shaped. One end of the guide vane 12 is fixedly connected to the second side plate 4 and is tangent to the second side plate 4. The other end of the guide vane 12 is fixedly connected to the inner circular surface 7 and is tangent to the inner circular surface 7.

[0057] The outer circular surface 8, the inner circular surface 7, the first side plate 3, and the second side plate 4 form an annular inner cavity and a rectangular airflow inlet 1, and the airflow inlet 1 is connected to the annular inner cavity.

[0058] The outer circular surface 8 can be cut from a ring-shaped tube or bent from a sheet metal; the inner circular surface 7 is formed by rolling and welding a tube or cutting a tube with different diameters.

[0059] The inner circular surface 7 is used to connect with the inner flow channel of the impeller 14 and guide the airflow in the inner flow channel to be smoothly discharged into the volute.

[0060] The guide vane 12 is used to connect the second side plate 4 and the inner circular surface 7, enhance the overall rigidity, and guide the airflow to reduce the impact of the airflow on the side plate.

[0061] This invention provides a design and manufacturing scheme for an intake / exhaust welded volute suitable for circumferential intake and axial exhaust or axial intake and circumferential exhaust blade machines, solving the problems of high manufacturing cost, long production cycle, and inability to effectively guarantee the error of flow channel dimensions in the past.

[0062] The inner circular surface 8 is frustum-shaped, so the airflow does not need to make a 90° turn inside, reducing flow loss. Simultaneously, as... Figure 3As shown, the use of a frustum shape, compared to a typical cylindrical shape, allows for more space for assembly and disassembly of the bolts connecting the second flange 11 of the welded volute and the impeller mechanism 14. Simultaneously, the frustum shape provides greater rigidity than a cylinder, better preventing deformation of the second flange 11 and thus ensuring the assembly accuracy between the volute and the impeller mechanism 14. The welded volute and its support 15 are connected to the base or ground.

[0063] This invention can quickly and efficiently process volutes using simple sheet metal and tubing profiles. During the processing, there is no need to weld multiple steel plates together to form an arc surface. There are fewer welds in the flow channel, the inner surface of the flow channel is smoother, the processing efficiency is high, and the cost is low.

[0064] Figure 3 A cross-sectional view of the welded volute and impeller mechanical assembly according to an embodiment of the present invention is shown. Figure 3 As shown, a first flange 10 is further fixedly provided at the circular opening of the first side plate 3;

[0065] A second flange 11 is fixedly provided at the other end of the inner circular surface 7 (the top circle of the inner circular surface 7);

[0066] The inner diameter of the first flange 10 is larger than the outer diameter of the second flange 11, and an annular airflow outlet 2 is formed between the two.

[0067] The first flange 10 and the second flange 11 are located on the same plane.

[0068] The first flange 10 is used to connect and fasten to the outer flow channel flange of the impeller 14, and also has a certain positioning function to prevent displacement of the impeller 14 and the volute during operation.

[0069] The second flange 11 is used to connect and fasten to the inner flow channel flange of the impeller 14, and also has a certain positioning function to prevent displacement of the impeller 14 and the volute during operation.

[0070] The first flange 10 and the second flange 11 of the welded volute are on the same plane. They can be machined in one step on a vertical lathe during machining to ensure the positional accuracy of the two planes and better guarantee the tightness of the fit between the two flanges of the volute and the workpiece. This will prevent a situation where one flange is tightened with bolts while the other flange is still leaking air.

[0071] Furthermore, the wall thickness of the guide vane 12 does not exceed the smaller of the wall thickness of the inner circular surface 7 and the wall thickness of the second side plate 4. When welding the guide vane 12, excessive welding stress will not cause large deformation of the volute.

[0072] Figure 2 A schematic diagram of the internal structure of a welded volute according to an embodiment of the present invention is shown. Figure 2As shown, further, the radius of the arc of the guide plate 12 is 1 / 4 to 1 / 2 times the distance between the first side plate 3 and the second side plate 4.

[0073] The larger the radius of the arc of the guide vane 12, the smoother the flow guidance effect. However, an excessively large arc radius also means a larger volume, which may cause blockage of the fluid channel. Therefore, the arc radius of the guide vane 12 is 1 / 4 to 1 / 2 of the distance between the front and rear side plates, which can ensure the flow guidance effect without blocking the fluid channel.

[0074] like Figure 3 As shown, the included angle between the inner circular surface 7 and the second side plate 4 is in the range of 120° to 135°.

[0075] When designing the taper of the inner circular surface 7, the exhaust angle of the internal flow channel of the impeller 14, the included angle between the inner circular surface 7 and the second side plate 4, and the machinability should be comprehensively considered. The included angle between the inner circular surface 7 and the second side plate 4 should be controlled between 120° and 135° to facilitate the machining of the inner circular surface 7 of the frustum and the welding construction of the inner circular surface 7 and the second side plate 4. Of course, when the exhaust angle of the internal flow channel of the impeller 14 is appropriate, the inner circular surface 7 can be designed to be consistent with the exhaust angle of the internal flow channel of the impeller 14, which will further reduce the exhaust loss of the impeller 14.

[0076] like Figure 4 As shown, the welded volute further includes: an inner reinforcing plate 5;

[0077] The inner reinforcing plate 5 has a boat-shaped overall cross section, which is composed of triangles, rectangles and triangles connected in sequence. It is set at the airflow inlet 1 and is parallel to the airflow direction and perpendicular to the first side plate 3 or the second side plate 4.

[0078] The front edge (triangle) and rear edge (triangle) of the inner reinforcing plate 5 form an acute angle, with the angle θ not exceeding 20°;

[0079] Both ends of the inner reinforcing plate 5 are rounded, with a rounding radius of not less than 2.5mm.

[0080] Among them, the inner reinforcing plate 5 can optimize its shape and position according to aerodynamic simulation to rectify the incoming flow and improve the flow field quality.

[0081] The inner reinforcing plate 5 is designed to be streamlined. When the airflow velocity is low, it can be simplified to a symmetrical structure with pointed ends and a thicker middle, with the pointed ends rounded. Generally, the angle of the pointed ends should not exceed 20° to consider airflow separation, and the rounding of the pointed ends should not be less than R2.5 to ensure sufficient strength. To ensure sufficient rigidity, the inner reinforcing plate 5 is generally thicker than the side plates.

[0082] The leading edge of the inner reinforcing plate should face the incoming flow direction, and the trailing edge should face the exhaust direction. At the same time, its leading edge should be located at the position where the fluid flow area changes abruptly.

[0083] When necessary, additional internal reinforcing plates 5 and guide vanes 12 can be arranged inside the volute to improve the uniformity of the flow field inside the volute and at the same time improve the overall rigidity of the volute so that it can withstand higher pressures.

[0084] like Figure 5 As shown, further, the center of the outer circular surface 8, the center of the top circle of the inner circular surface 7, and the central axis of the inner reinforcing plate 5 are located on the same straight line;

[0085] When 0.25 < r / R < 0.65, the eccentricity between the center of the outer circle 8 and the center of the top circle of the inner circle 7 is within the range of (0.65 * (R) / R. 2 -r 2 ) 0.5 -0.5r)~(0.8*(R 2 -r 2 ) 0.5 -0.45r);

[0086] Where r is the radius of the top circle of the inner circle 7; and R is the radius of the outer circle 8.

[0087] The aforementioned eccentricity range allows for a relatively gradual change in flow velocity within the volute, and the maximum flow velocity should be as low as possible. The value of the eccentricity is related to the difference between the radius of the outer circular surface 8 and the radius of the top circle of the inner circular surface 7. When the dimensions of the top circle of the inner circular surface 7 or the outer circular surface 8 are constant, the greater the difference between the two, the greater the eccentricity.

[0088] To ensure that the outflow velocity in each angular direction of the volute is approximately uniform, the inner and outer circular surfaces are eccentrically designed. The center of the top circle of the inner circular surface 7 does not coincide with the center of the outer circular surface 8. The center of the top circle of the inner circular surface 7 is further away from the connection surface with the pipe. This causes the flow cross-sectional area to decrease as the airflow flows circumferentially within the volute. This is because when the flow from the pipe flows within the volute, the airflow is redirected to flow into the impeller mechanism 14, resulting in less and less airflow within the volute. The corresponding gradual reduction in the flow cross-section ensures that the airflow velocity does not change significantly, reduces pressure loss caused by sudden changes in flow velocity, and improves the uniformity of the entire flow field.

[0089] Furthermore, weld the volute casing and add an outer reinforcing plate 6;

[0090] A plurality of outer reinforcing plates 6 are fixedly installed on the side wall of the outer circular surface 8; for example, the outer reinforcing plates 6 are disposed at the connection between the airflow inlet 1 and the arc-shaped surface of the outer circular surface 8.

[0091] The outer reinforcing plate 6 is provided with several lifting holes.

[0092] The outer reinforcing plate 6 can improve the overall strength and rigidity of the volute and can be machined with lifting holes for easy hoisting and installation.

[0093] Furthermore, the welding of the volute also includes: mounting plate 9;

[0094] Several mounting plates 9 are fixedly installed on the side wall of the outer circular surface 8;

[0095] The mounting plate 9 is provided with several mounting holes to facilitate the installation of the volute on the corresponding base.

[0096] The outer circular surface 8, side plates, and other thin-walled components are limited and also serve as reinforcing ribs by the volute mounting plate 9, outer reinforcing plate 6, inner reinforcing plate 5, and guide vanes 12, maintaining overall strength and ensuring the overall strength and rigidity of the volute under greater pressure and higher flow velocity.

[0097] like Figure 2 As shown, the welded volute also includes: a drain hole 13;

[0098] The drain hole 13 is located on the bottom of the outer circular surface 8.

[0099] The bottom of the welding volute is provided with a drain hole 13, which can be connected to an external plug or a drain valve. When the welding volute has been used for a long time and the internal liquid and dust accumulation is serious, the sewage can be drained through the drain hole 13.

[0100] The welding volute is fixedly installed on the welding volute bracket 15. The air supply / exhaust pipe is connected to the airflow inlet 1 of the welding volute. The first flange 10 and the second flange 11 are respectively connected to the impeller 14. When the welding volute is used for air intake of the impeller 14, air is supplied to the welding volute through the air supply pipe. The gas flows through the airflow inlet 1, is rectified by the inner reinforcing plate 5, and then guided by the guide vane 12 before flowing out from the airflow outlet 2 and into the interior of the impeller 14. When the welding volute is used for exhaust of the impeller 14, the installation method remains the same, but the airflow direction is reversed compared to the intake.

[0101] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A welded volute, characterized in that, include: First side plate (3), second side plate (4), inner circular surface (7), outer circular surface (8) and guide vane (12); One end of the outer circular surface (8) is connected to the first side plate (3), and the other end is connected to the second side plate (4); Both the first side plate (3) and the second side plate (4) are provided with circular openings; The inner circular surface (7) is frustum-shaped, and one end is connected to the circular opening of the second side plate (4); The inner circular surface (7) is uniformly provided with multiple guide vanes (12) around its periphery. The guide vane (12) is arc-shaped. One end of the guide vane (12) is fixedly connected to the second side plate (4), and the other end is fixedly connected to the inner circular surface (7). An annular cavity and an airflow inlet (1) are formed between the outer circular surface (8), the inner circular surface (7), the first side plate (3), and the second side plate (4), and the airflow inlet (1) is connected to the annular cavity; The radius of the arc of the guide plate (12) is 1 / 4 to 1 / 2 times the distance between the first side plate (3) and the second side plate (4); The included angle between the inner circular surface (7) and the second side plate (4) is in the range of 120°~135°; When 0.25 < r / R < 0.65, the eccentricity between the center of the outer circle (8) and the center of the top circle of the inner circle (7) is within the range of 0.65 * (R). 2 -r 2 ) 0.5 -0.5r ~ 0.8*(R) 2 -r 2 ) 0.5 -0.45r; Where r is the radius of the top circle of the inner circle (7); R is the radius of the outer circle (8).

2. The welded volute according to claim 1, characterized in that, A first flange (10) is provided at the circular opening of the first side plate (3); A second flange (11) is provided at the other end of the inner circular surface (7); The inner diameter of the first flange (10) is larger than the outer diameter of the second flange (11), and an annular airflow outlet (2) is formed between the two. The first flange (10) and the second flange (11) are located on the same plane.

3. The welded volute according to claim 1, characterized in that, The wall thickness of the guide plate (12) does not exceed the wall thickness of the inner circular surface (7) and the wall thickness of the second side plate (4).

4. The welded volute according to claim 1, characterized in that, Also includes: Inner reinforcing plate (5); The inner reinforcing plate (5) is boat-shaped and is located at the airflow inlet (1) and parallel to the airflow direction. The front and rear edges of the inner reinforcing plate (5) are at acute angles, not exceeding 20°. The inner reinforcing plate (5) has two rounded tips with a radius of not less than 2.5 mm.

5. The welded volute according to claim 4, characterized in that, The center of the outer circular surface (8), the center of the top circle of the inner circular surface (7), and the central axis of the inner reinforcing plate (5) are located on the same straight line.

6. The welded volute according to claim 1, characterized in that, It also includes: outer reinforcing plate (6); Several outer reinforcing plates (6) are fixedly installed on the side wall of the outer circular surface (8); The outer reinforcing plate (6) is provided with several lifting holes.

7. The welded volute according to claim 1, characterized in that, Also includes: Mounting plate (9); Several mounting plates (9) are fixedly installed on the side wall of the outer circular surface (8); The mounting plate (9) is provided with several mounting holes.

8. The welded volute according to claim 1, characterized in that, Also includes: Drain hole (13); The drain hole (13) is located on the outer circular surface (8).

Images