A high-efficiency centrifugal fan for material conveying with a non-axial air inlet

Abstract

This invention relates to the centrifugal fan industry, and particularly to a high-efficiency material conveying centrifugal fan with a non-axial air inlet. The fan includes a volute, an impeller fixedly disposed within the volute, and an air inlet fixedly connected to the volute. The air inlet extends into the volute and is non-coaxial with the impeller, with a gap between them. The air inlet includes a connecting portion, a guide section, an inlet section, and a guide section. The guide section is fixedly connected to the volute via the connecting portion. The inlet of the guide section forms the inlet section, and the outlet of the guide section forms the guide section. The guide section is configured as a slanted cylindrical structure. This invention provides a high-efficiency material conveying centrifugal fan with a non-axial air inlet. By employing a non-axial air inlet, a front-disc-less impeller, and a matching volute profile design, it improves the problem of low material conveying efficiency caused by material blockage such as jamming during feeding in existing material conveying centrifugal fans.

Description

Technical Field

[0001] This invention relates to the centrifugal fan industry, and in particular to a high-efficiency material conveying centrifugal fan with a non-axial air inlet. Background Technology

[0002] Centrifugal fans, as supporting conveying equipment for materials such as air, grain, feed, mineral powder, raw materials, and production waste, are widely used in various sectors of the national economy. For example, the production and processing of cardboard boxes generates a large amount of scrap material. Since cardboard box production lines operate at high speeds, the traditional method involves setting up dedicated stations to remove and recycle the excess scrap material. However, manually collecting and recycling scrap material is inefficient. Therefore, centrifugal fans are needed to collect and recycle the large amounts of scrap material generated during cardboard box production to improve efficiency.

[0003] When using centrifugal fans for material conveying, it is essential to ensure the accuracy of material delivery. Materials are guided and conveyed through ducts by the fan. During this process, the material passes inside the fan body. However, due to the structural characteristics of traditional fans, ordinary fans are prone to blockages such as material accumulation at the feeding port, which prevents the material from passing smoothly through the fan body, reducing conveying efficiency and consequently affecting normal production.

[0004] The existing centrifugal fans for material conveying need to be improved. Summary of the Invention

[0005] The purpose of this invention is to provide a high-efficiency centrifugal fan for material conveying with a non-axial air inlet, which aims to solve the problem of low material conveying efficiency caused by material blockage such as jamming and accumulation at the inlet during material conveying in existing centrifugal fans.

[0006] To achieve the above objectives, a high-efficiency material conveying centrifugal fan with a non-axial air inlet includes a volute, an impeller fixedly disposed within the volute, and an air inlet fixedly connected to the volute.

[0007] The air inlet extends into the volute, and the air inlet and the impeller are not coaxially arranged, with a gap between the air inlet and the impeller.

[0008] The air inlet includes a connecting part, a guide section, an air inlet, and a guide section. The guide section is fixedly connected to the volute through the connecting part. The inlet of the guide section forms the air inlet, and the outlet of the guide section forms the guide section.

[0009] The air guide section is designed as an inclined cylindrical structure. In the top view of the air guide section, the angle ∠1 between the air guide section and the air guide part is 75°-76°. The radius of the air inlet part is R1, and the radius of the air guide part is R2. R1 and R2 are equal and both are 94mm-95mm.

[0010] The vertical distance L2 between the air inlet and the connecting part is 99mm-101mm, and the vertical distance L1 between the air guide and the connecting part is 14.6mm-15.4mm.

[0011] Furthermore, ∠1 is 75.58°, R1 is 94.5mm, L2 is 100mm, and L1 is 15mm.

[0012] Furthermore, the impeller includes a hub and a rear disc, with the rear disc fixedly mounted on the hub and multiple blades arranged in an array around the rear disc;

[0013] The blade includes a straight blade portion near the hub and an arc blade portion away from the hub. The straight blade portion includes a straight section away from the hub and an inclined section near the hub. The inclined section is inclined from the straight section toward the hub.

[0014] Furthermore, the vertical distance L3 between the trailing edge of the blade and the rear disk is 119mm-121.2mm;

[0015] The impeller is cut along a plane passing through its central axis. The length of the inclined section L1 is 84mm-86mm, the length of the straight section L2 is 30.2mm-40.2mm, the angle ∠4 between the inclined section and the straight section is 134°-136°, and the vertical distance L8 between the straight section and the air guide is 12.8mm-13.2mm.

[0016] Furthermore, the inlet angle ∠2 during blade installation is 11°-11.6°, the outlet angle ∠3 during blade installation is 34.5°-35.5°, and on the projection surface of the rear disc, the radius R3 of the arc blade part is 69mm-70mm and the arc length is 80mm-81.5mm;

[0017] The diameter φ1 of the outer circumference formed by the outer ends of all the blades of the impeller is 400mm, and the diameter φ2 of the outer circumference formed by the outer ends of the straight blades is 263mm-266.5mm.

[0018] The blade thickness t1 is 4.8mm-5.2mm, and there are 8 blades.

[0019] Furthermore, wear-resistant welds are provided on the arc blade section, and the thickness t2 of the wear-resistant welds is 2.4mm-2.6mm;

[0020] L3 is 120mm, L1 is 84.9mm, L2 is 30.7mm, ∠4 is 135°, L8 is 13mm, ∠2 is 11.3°, ∠3 is 35°, R3 is 69.6mm and its arc length is 80.7mm, φ2 is 264.8mm, and t1 is 5mm.

[0021] Furthermore, the profile of the volute includes a first diffuser straight segment, a volute tongue segment, a first arc segment, a second arc segment, a third arc segment, a fourth arc segment, and a second diffuser straight segment connected tangentially in sequence; the first diffuser straight segment and the second diffuser straight segment enclose and form an air outlet, and the first arc segment, the second arc segment, the third arc segment, and the fourth arc segment are not concentric;

[0022] Establish a rectangular coordinate system with the center of the impeller as the origin. When the first diffuser straight segment is located in the third quadrant, the coordinates of the center O2 of the first arc segment are (-21.8, 21.8), the radius R5 is 223mm-225mm, and the arc length is 123mm-126mm. The coordinates of the center O1 of the second arc segment are (21.8, 21.8), the radius R6 is 244.7mm-247.3mm, and the arc length is 384.5mm-3. The center O4 of the third arc segment is (21.8, -21.8), the radius R7 is 266.4mm-269.6mm, and the arc length is 418mm-423.5mm. The center O3 of the fourth arc segment is (-21.8, -21.8), the radius R8 is 288mm-292mm, and the arc length is 452mm-458mm. The first and second diffuser straight segments are both set perpendicular to the air outlet.

[0023] Furthermore, the width L5 of the air outlet is 159mm-161mm, and the height L4 is 170mm-174mm;

[0024] The radius R4 of the volute tongue segment is 13.5mm-14.5mm and the arc length is 29mm-30.5mm. The length L6 of the first diffuser straight segment is 27mm-28mm, and the length L7 of the second diffuser straight segment is 228mm-232mm. A tangent line is drawn to the volute tongue segment with the tangent point between the volute tongue segment and the first arc segment as the tangent point. The angle ∠5 between this tangent line and the first diffuser straight segment is 57.9°-58.5°.

[0025] Furthermore, a rectangular coordinate system is established with the center of the impeller as the origin. When the first diffuser straight segment is located in the third quadrant, the coordinates of the center O2 of the first arc segment are (-21.8, 21.8), the radius R5 is 224 mm and the arc length is 124.4 mm; the coordinates of the center O1 of the second arc segment are (21.8, 21.8), the radius R6 is 246 mm and the arc length is 386.4 mm; the coordinates of the center O4 of the third arc segment are (21.8, -21.8), the radius R7 is 268 mm and the arc length is 420.7 mm; and the coordinates of the center O3 of the fourth arc segment are (-21.8, -21.8), the radius R8 is 290 mm and the arc length is 454.9 mm.

[0026] L5 is 160mm, L4 is 172mm, R4 is 14mm with an arc length of 29.8mm, L6 is 27.5mm, L7 is 229.9mm, and ∠5 is 58.22°.

[0027] Furthermore, it also includes a motor and a base. The motor is connected to the impeller via a motor shaft, and both the volute and the motor are fixedly mounted on the base.

[0028] The present invention provides a high-efficiency material conveying centrifugal fan with a non-axial air inlet:

[0029] (1) The air inlet is non-axial and the air inlet is designed to be non-coaxial with the impeller, which realizes the non-coaxial air intake and material intake method, replacing the traditional concentric axial air intake and material intake method, effectively avoiding blockage caused by shaft disc problems and improving material conveying efficiency.

[0030] (2) By designing an impeller without a front disc, the material feed flow is increased, which further improves the material conveying efficiency. At the same time, it can effectively reduce the impact loss and noise of the airflow to the impeller inlet. Meanwhile, wear-resistant welding is added to the working surface of the blades to achieve wear resistance and improve the working life of the fan.

[0031] (3) The circular arc transition structure of the logarithmic spiral volute profile ensures smooth and efficient airflow within the volute, reduces airflow impact and energy loss, thereby improving fan efficiency; by optimizing the volute outlet and volute tongue section to match the impeller, the impact loss and separation of airflow are reduced, the high-efficiency operating range of the fan is broadened, the total pressure and fan efficiency are improved, the material conveying efficiency is further improved, and the fan noise is reduced. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the centrifugal fan of the present invention;

[0033] Figure 2 This is a schematic diagram of the profile of the volute.

[0034] Figure 3 This is a schematic diagram of the side cross-sectional structure of the volute.

[0035] Figure 4 This is a schematic diagram of the impeller structure;

[0036] Figure 5 This is a side sectional view of the impeller.

[0037] Figure 6 This is a top sectional view of the air inlet;

[0038] Figure 7 This is a performance curve of the high-efficiency material conveying centrifugal fan with a non-axial air inlet of the present invention;

[0039] Figure 8 This is a performance curve graph with a proportional ratio.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1. Volute; 11. First diffuser straight section; 12. Volute tongue section; 13. First arc section; 14. Second arc section; 15. Third arc section; 16. Fourth arc section; 17. Second diffuser straight section; 18. Air outlet;

[0042] Impeller 2; Blade 21; Straight blade section 211; Inclined section 2111; Straight section 2112; Arc blade section 212; Wear-resistant weld 2121; Back plate 22;

[0043] Air inlet 3; Connecting part 31; Air guide section 32; Air inlet 33; Air guide section 34;

[0044] 4 motors; 5 machine bases. Detailed Implementation

[0045] The present invention will be described in detail below with reference to specific embodiments.

[0046] In this invention, unless otherwise explicitly specified and limited, terms such as "set in," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or a connection through one or more intermediate media. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The directional terms appearing in this invention are for the purpose of better describing the characteristics of the features and the relationships between them. It should be understood that when the orientation of this invention changes, the orientation of the characteristics of the features and the relationships between them also changes accordingly. Therefore, directional terms do not constitute an absolute spatial limitation on the characteristics of the features and the relationships between them, but only a relative limitation.

[0047] The structural parameters used in this invention are only for illustrating the technical solution of this invention. That is, based on the basic structural parameters of this invention, reasonable proportional scaling can be performed in actual production (for example, when the diameter of the impeller is 400mm, it can be scaled by 0.1-30 times, etc.). Such reasonable proportional scaling also falls within the protection scope of this invention.

[0048] Please see Figure 1-8 A high-efficiency material conveying centrifugal fan with a non-axial air inlet includes a volute 1, an impeller 2 fixedly disposed inside the volute 1, and an air inlet 3 fixedly connected to the volute 1.

[0049] The air inlet 3 extends into the volute 1. The air inlet 3 and the impeller 2 are not coaxially arranged, and there is a gap between the air inlet 3 and the impeller 2.

[0050] The air inlet 3 includes a connecting part 31, a guide section 32, an air inlet 33 and a guide section 34. The guide section 32 is fixedly connected to the volute 1 through the connecting part 31. The inlet of the guide section 32 forms the air inlet 33 and the outlet of the guide section 32 forms the guide section 34.

[0051] The air guide section 32 is set as an oblique cylindrical structure. In the top view of the air guide section 32, the angle ∠1 between the air guide section 32 and the air guide part 34 is 75°-76°. The radius of the air inlet part 33 is R1, and the radius of the air guide part 34 is R2. R1 and R2 are equal and both are 94mm-95mm.

[0052] The vertical distance L2 between the air inlet 33 and the connecting part 31 is 99mm-101mm, and the vertical distance L1 between the air guide 34 and the connecting part 31 is 14.6mm-15.4mm.

[0053] Preferably, ∠1 is 75.58°, R1 is 94.5mm, L2 is 100mm, and L1 is 15mm.

[0054] By adopting the above technical solution, a non-axial air inlet 3 is used, and the air inlet 3 and impeller 2 are designed to be non-coaxial, so as to realize the non-coaxial air intake and material intake method, which replaces the traditional concentric axial (i.e. central axial) air intake and material intake method, effectively avoiding blockage caused by shaft disc problems and improving material conveying efficiency.

[0055] In this embodiment, the impeller 2 includes a hub and a rear disc 22. The rear disc 22 is fixedly mounted on the hub, and a plurality of blades 21 are arranged in an array around the rear disc 22.

[0056] The blade 21 includes a straight blade portion 211 near the hub and an arc blade portion 212 away from the hub. The straight blade portion 211 includes a straight section 2112 away from the hub and an inclined section 2111 near the hub. The inclined section 2111 is inclined from the straight section 2112 toward the hub.

[0057] In this embodiment, the vertical distance L3 between the trailing edge of the blade 21 and the rear disk 22 is 119mm-121.2mm; preferably, L3 is 120mm.

[0058] The impeller 2 is cut along a plane passing through its central axis. In this cross-section, the length L1 of the inclined section 2111 is 84mm-86mm, the length L2 of the straight section 2112 is 30.2mm-40.2mm, the angle ∠4 between the inclined section 2111 and the straight section 2112 is 134°-136°, and the vertical distance L8 between the straight section 2112 and the air guide 34 is 12.8mm-13.2mm. Preferably, L1 is 84.9mm, L2 is 30.7mm, ∠4 is 135°, and L8 is 13mm.

[0059] In this embodiment, the inlet angle ∠2 of the blade 21 during installation is 11°-11.6°, and the outlet angle ∠3 of the blade 21 during installation is 34.5°-35.5°. On the projection surface of the rear disc 22, the radius R3 of the arc blade portion 212 is 69mm-70mm and the arc length is 80mm-81.5mm; preferably, ∠2 is 11.3°, ∠3 is 35°, R3 is 69.6mm and the arc length is 80.7mm.

[0060] The diameter φ1 of the outer circumference formed by the outer ends of all the blades 21 of the impeller 2 is 400 mm, and the diameter φ2 of the circumference formed by the outer ends of the straight blades 211 is 263 mm-266.5 mm; preferably, φ2 is 264.8 mm.

[0061] The thickness t1 of the blade 21 is 4.8mm-5.2mm, and there are 8 blades 21. Preferably, t1 is 5mm.

[0062] Furthermore, the arc blade is provided with wear-resistant weld 2121, and the thickness t2 of the wear-resistant weld 2121 is 2.4mm-2.6mm; preferably, t2 is 2.5mm.

[0063] Through the above technical solution, the design of the impeller 2 without a front disc increases the material feeding flow and further improves the material conveying efficiency. At the same time, it can effectively reduce the impact loss and noise of the airflow to the inlet of the impeller 2. Meanwhile, the addition of wear-resistant weld 2121 on the working surface of the blade 21 has an anti-wear effect. Eliminating the front disc can reduce the weight of the impeller 2 and improve the service life of the fan.

[0064] In this embodiment, the profile of the volute 1 includes a first diffuser straight segment 11, a volute tongue segment 12, a first arc segment 13, a second arc segment 14, a third arc segment 15, a fourth arc segment 16, and a second diffuser straight segment 17 connected tangentially in sequence; the first diffuser straight segment 11 and the second diffuser straight segment 17 enclose and form an air outlet 18, and the first arc segment 13, the second arc segment 14, the third arc segment 15, and the fourth arc segment 16 are not concentric;

[0065] A rectangular coordinate system is established with the center of impeller 2 as the origin. When the first diffuser straight segment 11 is located in the third quadrant, the coordinates of the center O2 of the first arc segment 13 are (-21.8, 21.8), the radius R5 is 223mm-225mm, and the arc length is 123mm-126mm. The coordinates of the center O1 of the second arc segment 14 are (21.8, 21.8), the radius R6 is 244.7mm-247.3mm, and the arc length is 384.5mm-388mm. mm, the center O4 of the third arc segment 15 is (21.8, -21.8), the radius R7 is 266.4mm-269.6mm and the arc length is 418mm-423.5mm, the center O3 of the fourth arc segment 16 is (-21.8, -21.8), the radius R8 is 288mm-292mm and the arc length is 452mm-458mm, the first diffuser straight segment 11 and the second diffuser straight segment 17 are both set perpendicular to the air outlet 18.

[0066] Preferably, a rectangular coordinate system is established with the center of the impeller 2 as the origin. When the first diffuser straight line segment 11 is located in the third quadrant, the center O2 of the first arc segment 13 has coordinates of (-21.8, 21.8), radius R5 is 224mm and arc length is 124.4mm, the center O1 of the second arc segment 14 has coordinates of (21.8, 21.8), radius R6 is 246mm and arc length is 386.4mm, the center O4 of the third arc segment 15 has coordinates of (21.8, -21.8), radius R7 is 268mm and arc length is 420.7mm, and the center O3 of the fourth arc segment 16 has coordinates of (-21.8, -21.8), radius R8 is 290mm and arc length is 454.9mm.

[0067] In this embodiment, the width L5 of the air outlet 18 is 159mm-161mm and the height L4 is 170mm-174mm;

[0068] The radius R4 of the volute tongue segment 12 is 13.5mm-14.5mm and the arc length is 29mm-30.5mm. The length L6 of the first diffuser straight segment 11 is 27mm-28mm, and the length L7 of the second diffuser straight segment 17 is 228mm-232mm. A tangent line is drawn to the volute tongue segment 12 at the point of tangency between the volute tongue segment 12 and the first arc segment 13. The angle ∠5 between this tangent line and the first diffuser straight segment 11 is 57.9°-58.5°. Preferably, L5 is 160mm, L4 is 172mm, R4 is 14mm and the arc length is 29.8mm, L6 is 27.5mm, L7 is 229.9mm, and ∠5 is 58.22°.

[0069] In this embodiment, a motor 4 and a base 5 are also included. The motor 4 is connected to the impeller 2 via a motor shaft. Both the volute 1 and the motor 4 are fixedly mounted on the base 5.

[0070] Through the above technical solution, the circular arc transition structure of the logarithmic spiral volute 1 ensures smooth and efficient airflow within the volute 1, reduces airflow impact and energy loss, thereby improving fan efficiency. By optimizing the air outlet and volute tongue section 12 of the volute 1 to match the impeller 2, the impact loss and separation of airflow are reduced, the high-efficiency operating range of the fan is broadened, the total pressure and fan efficiency are improved, the material conveying efficiency is further improved, and the fan noise is reduced.

[0071] To verify this embodiment, based on the preferred structural parameters provided in this embodiment, a high-efficiency material conveying centrifugal fan with a non-axial air inlet was fabricated with an impeller 2 diameter (i.e., the diameter of the outer circumference formed by the outer ends of all blades 21 of the impeller 2) of 400 mm as a test example was tested. Simultaneously, a conventional material conveying centrifugal fan with a conventional impeller 2 of 400 mm diameter and a coaxial arrangement of the impeller and air inlet was fabricated as a comparative example for testing. The test results were converted to atmospheric pressure of 101325 Pa, atmospheric temperature of 20 ℃, fan speed of 2900 r / min, and medium density of 1.2 kg / m³. 3 Test data under test conditions, and test examples yielded the test data shown in Table 1. Figure 7 The performance curves shown are used to derive test data as shown in Table 2. Figure 8 The performance curves shown have volumetric flow rate as the horizontal axis. In the performance curves, qvsglGu is the volumetric flow rate, LAGu is the A-weighted sound level, ηr is the fan efficiency, PrGu is the impeller power, pFGu is the total pressure, and psFGu is the static pressure.

[0072] Table 1

[0073]

[0074] Table 2

[0075]

[0076] The test data and performance curves show that, compared to the test case, the comparative example is inferior to the test case in terms of volumetric flow range, total pressure, fan efficiency, and A-weighted sound level. In contrast, the test case has a volumetric flow range of 1325.5 m³ / s. 3 / h-4417.2m 3 The optimal fan efficiency is 68.978% per hour, with a total pressure of 3232.2 Pa and an A-weighted sound level of 89.495 dB. The volumetric flow rate range for the test case is 1612.5 m³ / h. 3 / h-4062.4m 3The optimal fan efficiency is 65.987% at / h, with a total pressure of 2292.9 Pa and an A-weighted sound level of 95.264 dB. The test cases generally have a larger volumetric flow rate range, higher total pressure, and higher fan efficiency compared to the comparative examples, and the A-weighted sound level of the test cases is generally lower than that of the comparative examples.

[0077] Compared with the prior art, the present invention provides a high-efficiency material conveying centrifugal fan with a non-axial air inlet. By adopting a non-axial air inlet, a front-disc-less impeller, and a matching volute profile design, it improves the problem of low material conveying efficiency caused by material blockage such as jamming during feeding and conveying in existing material conveying centrifugal fans.

[0078] Where there is no conflict, the above embodiments and features can be combined with each other.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A high-efficiency centrifugal fan for material conveying with a non-axial air inlet, comprising a volute, an impeller fixedly disposed within the volute, and an air inlet fixedly connected to the volute, characterized in that: The air inlet extends into the volute, and the air inlet and the impeller are not coaxially arranged, with a gap between the air inlet and the impeller. The air inlet includes a connecting part, a guide section, an air inlet, and a guide section. The guide section is fixedly connected to the volute through the connecting part. The inlet of the guide section forms the air inlet, and the outlet of the guide section forms the guide section. The air guide section is designed as an inclined cylindrical structure. In the top view of the air guide section, the angle ∠1 between the air guide section and the air guide part is 75°-76°. The radius of the air inlet part is R1, and the radius of the air guide part is R2. R1 and R2 are equal and both are 94mm-95mm. The vertical distance L2 between the air inlet and the connecting part is 99mm-101mm, and the vertical distance L1 between the air guide and the connecting part is 14.6mm-15.4mm; The impeller includes a hub and a rear plate, with the rear plate fixedly mounted on the hub and multiple blades arranged in an array around the rear plate; The blade includes a straight blade portion near the hub and an arc blade portion away from the hub. The straight blade portion includes a straight section away from the hub and an inclined section near the hub. The inclined section is inclined from the straight section toward the hub. The profile of the volute includes a first diffuser straight segment, a volute tongue segment, a first arc segment, a second arc segment, a third arc segment, a fourth arc segment, and a second diffuser straight segment that are connected tangentially in sequence; the first diffuser straight segment and the second diffuser straight segment enclose and form an air outlet, and the first arc segment, the second arc segment, the third arc segment, and the fourth arc segment are not concentric; Establish a rectangular coordinate system with the center of the impeller as the origin. When the first diffuser straight segment is located in the third quadrant, the coordinates of the center O2 of the first arc segment are (-21.8, 21.8), the radius R5 is 223mm-225mm, and the arc length is 123mm-126mm. The coordinates of the center O1 of the second arc segment are (21.8, 21.8), the radius R6 is 244.7mm-247.3mm, and the arc length is 384.5mm-3. The center O4 of the third arc segment is (21.8, -21.8), the radius R7 is 266.4mm-269.6mm, and the arc length is 418mm-423.5mm. The center O3 of the fourth arc segment is (-21.8, -21.8), the radius R8 is 288mm-292mm, and the arc length is 452mm-458mm. The first and second diffuser straight segments are both set perpendicular to the air outlet.

2. The high-efficiency material conveying centrifugal fan with a non-axial air inlet according to claim 1, characterized in that: ∠1 is 75.58°, R1 is 94.5mm, L2 is 100mm, and L1 is 15mm.

3. A high-efficiency material conveying centrifugal fan with a non-axial air inlet according to claim 2, characterized in that: The vertical distance L3 between the trailing edge of the blade and the rear disk is 119mm-121.2mm; The impeller is cut along a plane passing through its central axis. The length of the inclined section L1 is 84mm-86mm, the length of the straight section L2 is 30.2mm-40.2mm, the angle ∠4 between the inclined section and the straight section is 134°-136°, and the vertical distance L8 between the straight section and the air guide is 12.8mm-13.2mm.

4. A high-efficiency material conveying centrifugal fan with a non-axial air inlet according to claim 3, characterized in that: The inlet angle ∠2 during blade installation is 11°-11.6°, and the outlet angle ∠3 during blade installation is 34.5°-35.5°. On the projection surface of the rear disc, the radius R3 of the arc blade part is 69mm-70mm and the arc length is 80mm-81.5mm. The diameter φ1 of the outer circumference formed by the outer ends of all the blades of the impeller is 400mm, and the diameter φ2 of the outer circumference formed by the outer ends of the straight blades is 263mm-266.5mm. The blade thickness t1 is 4.8mm-5.2mm, and there are 8 blades.

5. A high-efficiency material conveying centrifugal fan with a non-axial air inlet according to claim 4, characterized in that: Wear-resistant welds are provided on the arc blade section, and the thickness t2 of the wear-resistant welds is 2.4mm-2.6mm; L3 is 120mm, L1 is 84.9mm, L2 is 30.7mm, ∠4 is 135°, L8 is 13mm, ∠2 is 11.3°, ∠3 is 35°, R3 is 69.6mm and its arc length is 80.7mm, φ2 is 264.8mm, and t1 is 5mm.

6. A high-efficiency material conveying centrifugal fan with a non-axial air inlet according to claim 5, characterized in that: The width L5 of the air outlet is 159mm-161mm, and the height L4 is 170mm-174mm; The radius R4 of the volute tongue segment is 13.5mm-14.5mm and the arc length is 29mm-30.5mm. The length L6 of the first diffuser straight segment is 27mm-28mm, and the length L7 of the second diffuser straight segment is 228mm-232mm. A tangent line is drawn to the volute tongue segment with the tangent point between the volute tongue segment and the first arc segment as the tangent point. The angle ∠5 between this tangent line and the first diffuser straight segment is 57.9°-58.5°.

7. A high-efficiency material conveying centrifugal fan with a non-axial air inlet according to claim 6, characterized in that: A rectangular coordinate system is established with the center of the impeller as the origin. When the first diffuser straight segment is located in the third quadrant, the coordinates of the center O2 of the first arc segment are (-21.8, 21.8), the radius R5 is 224 mm and the arc length is 124.4 mm; the coordinates of the center O1 of the second arc segment are (21.8, 21.8), the radius R6 is 246 mm and the arc length is 386.4 mm; the coordinates of the center O4 of the third arc segment are (21.8, -21.8), the radius R7 is 268 mm and the arc length is 420.7 mm; and the coordinates of the center O3 of the fourth arc segment are (-21.8, -21.8), the radius R8 is 290 mm and the arc length is 454.9 mm. L5 is 160mm, L4 is 172mm, R4 is 14mm with an arc length of 29.8mm, L6 is 27.5mm, L7 is 229.9mm, and ∠5 is 58.22°.

8. A high-efficiency material conveying centrifugal fan with a non-axial air inlet according to claim 7, characterized in that: It also includes a motor and a base. The motor is connected to the impeller via a motor shaft, and both the volute and the motor are fixedly mounted on the base.

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