Multi-dimensional composite fan and roller type granulator using same for dust removal

Abstract

The invention discloses a multi-dimensional composite fan and a roller type granulator using the same for dust removal. A centrifugal impeller comprises a flow guide part, a composite blade part, a flexible telescopic guide blade and an outflow blade, wherein the flow guide part is mounted on a motor shaft, the composite blade part and the flexible telescopic guide blade are arranged on a hub, and the outflow blade is arranged between an upper wheel cover and a lower wheel cover. The flow guide part, the composite blade part and the flexible telescopic guide blade are sequentially arranged in the flow path direction. The upper wheel cover comprises a buffer cavity section and an upper wheel cover outlet section which are connected in sequence; the buffer cavity section comprises an axial buffer inlet, a buffer cavity and a composite blade side buffer outlet; the composite blade part comprises a first blade mounted on the hub, a blade ring fixedly connected with the outer side of the first blade and a second blade mounted on the outer side of the blade ring, and the blade top of the second blade is located in the buffer cavity, so that the air volume and the air pressure are stable, the unbalance loss of the impeller is reduced, and turbulence suppression and resonance control are facilitated through the arrangement of the flow guide part.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid machinery, in particular to a fan, and more particularly to a multi-dimensional composite fan and a double-roller granulator using the same for dust removal. Background Art

[0002] In existing fluid machinery, when fans are used in special circumstances, such as in dust removal equipment, there may be long-term wear and tear that may lead to impeller imbalance; dust accumulation may lead to blockage, which in turn affects the air volume and air pressure of the fan, increasing energy consumption; and severe corrosion of the blades may produce noise, among other problems. Traditional fans do not perform well in complex working conditions, which limits their scope of application, especially when used in the industrial process of dust removal of roller granulators. As the core component of transportation, its performance directly affects the quality and efficiency of granulation, such as insufficient flow control accuracy, transportation difficulties, leakage and pollution, maintenance and lifespan. Therefore, it is particularly important to develop a multi-dimensional composite fan and use it in roller granulators to solve the above problems.

[0003] Prior art CN102720698A discloses a fan having a plurality of blades 7 arranged in an annular array between the front cover plate 5 and the rear cover plate 6. The blades 7 are vertically arranged between the front cover plate 5 and the rear cover plate 6; the blades 7 are welded to the front cover plate 5 and the rear cover plate 6; the blades 7 are arc-shaped; and the extension line connecting the outer center and the inner center of the blade 7 passes through the center of the front cover plate 5 and the rear cover plate 6. During the process of exhausting gas from the fan, no airflow with a deviated direction is generated, thus avoiding exhaust losses of the fan. At the same time, the probability of gas turbulence or vortex caused by external interference is also reduced, and fatigue cracks or resonance of the impeller blades are avoided. Furthermore, the phenomenon of impeller blade breakage is avoided, and the time of fan downtime for maintenance is reduced, thereby increasing the exhaust efficiency of the fan.

[0004] The prior art CN119528624A discloses a clean production process for blended fertilizers. The bottom end of the wind ball 11 has a mounting portion 41 for extending into the silo 1. A fan 42 is provided in the mounting portion 41. The air outlet direction of the fan 42 is toward the wind ball 11. With the further design of the fan 42, the air flow efficiency can be improved, and the ventilation effect of the wind ball 11 can be improved. The bottom end of the mounting portion 41 is an air exchange port, and a cloth bag 12 is provided at the air exchange port. The cloth bag 12 is used to block and suppress the discharge of dust in the silo body 2, effectively preventing dust from rising. In addition, a vertical rod 43 is provided on the fan 42, and the bottom end of the rod 43 abuts the cloth bag 12. The vibration generated when the fan 42 is working can be transmitted to the cloth bag 12 through the rod 43, causing the cloth bag 12 to shake, so that the dust adhering to the cloth bag 12 can be shaken off, avoiding the clogging of the cloth bag 12 and affecting the ventilation effect, thereby realizing automatic clearing of the cloth bag 12.

[0005] The above-mentioned prior arts all involve the application of relevant fans. However, the above-mentioned structures have design limitations, and in the actual application of the fans, there are still problems of instability, vibration and noise. Therefore, in response to these problems, the applicant proposes a multi-dimensional composite fan and a double-roller granulator using the same for dust removal. Summary of the Invention

[0006] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a multi-dimensional composite fan and a double-roller granulator using the same for dust removal.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A multi-dimensional composite fan comprises a volute, a variable frequency motor and a multi-dimensional composite centrifugal impeller, the centrifugal impeller comprising an upper wheel cover, a lower wheel cover and a hub; a variable frequency motor is provided at the rear end of the volute, the centrifugal impeller is arranged in the volute, and the variable frequency motor is connected to the centrifugal impeller hub through a motor shaft; the centrifugal impeller further comprises a guide portion mounted on the motor shaft, a composite blade portion and a flexible retractable guide vane on the hub, and an outflow blade between the upper wheel cover and the lower wheel cover, which are arranged in sequence along the flow path direction; the upper wheel cover comprises a buffer cavity section and an upper wheel cover outlet section connected in sequence, the buffer cavity section comprises an axial buffer inlet, a buffer cavity and a composite blade side buffer outlet; the composite blade section comprises a first blade mounted on the hub, a blade ring fixedly connected to the outer side of the first blade and a second blade mounted on the outer side of the blade ring, wherein the blade tip of the second blade is located in the buffer cavity, the blade root is located in the main flow channel, and there is a flow gap between the blade ring and the upper wheel cover; the flexible retractable guide vane can be retracted and bent in the flow channel between the composite blade portion and the outflow blade to change the position and structural size of the flexible retractable guide vane.

[0009] Furthermore, it also includes a control unit and a position sensor, wherein the position sensor monitors the position information of the flexible retractable guide vane relative to a predetermined reference position and the blade structural dimension information in real time; the control unit adjusts the position and structural dimension of the flexible retractable guide vane in real time according to the real-time working condition of the variable frequency motor and the feedback signal of the position sensor to optimize the flow diversion performance.

[0010] Furthermore, the flexible and retractable guide vanes are made of carbon fiber reinforced composite materials or memory alloy materials.

[0011] Furthermore, the impeller inlet radius is R, wherein the flow gap size is (0.05-0.2)R.

[0012] Furthermore, in a cross-sectional view of the center axis of the second blade, a cross-sectional length of the second blade in the buffer cavity is 6 to 10 times a cross-sectional length of the second blade in the main flow channel.

[0013] Furthermore, the buffer cavity is a fan-shaped or rectangular structure.

[0014] Furthermore, the guide part adopts a double guide ring structure, which includes a first guide ring fixedly connected to the motor shaft, a second guide ring, and a connecting blade connecting the first guide ring and fixing the second guide ring, wherein the connecting blade is a backward inclined blade.

[0015] Furthermore, the first guide ring includes a horizontal inlet ring segment and a first inclined ring segment, and the axis center line of the horizontal inlet ring segment is collinear with the axis center line of the motor shaft.

[0016] Furthermore, the second guide ring includes a vertical inlet ring segment and a second inclined ring segment, and the plane where the vertical inlet ring segment is located is perpendicular to the axis of the motor shaft.

[0017] Furthermore, the first inclined ring segment and the second inclined ring segment are parallel to each other in space, and the distance between them is H=(0.2-0.5)R, where R is the impeller inlet radius.

[0018] Furthermore, the included angle A between the first inclined ring segment, the second inclined ring segment and the motor shaft centerline is 30° to 60°.

[0019] A double-roller granulator comprises a frame, a hopper arranged on the frame, and a pair of granulating rollers located below the hopper. The granulating rollers are rotatably connected to the frame and driven by a driving device. The machine is characterized in that a fan dust removal system is also provided, and the fan dust removal system comprises a fan, a dust hood, a dust collecting box and a filtering device; the dust hood is arranged above and on both sides of the granulating roller, the dust hood is connected to the air inlet of the fan through a pipe, and the air outlet of the fan is connected to the dust collecting box, and a filtering structure is provided in the dust collecting box; the fan is a multi-dimensional composite fan.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. In the prior art, when conventional fans are used under special working conditions, such as in dust removal equipment, dust accumulation causes blockage, which in turn affects the air volume and air pressure of the fan and increases energy consumption. To address the above problems, the present invention adopts a centrifugal impeller comprising a guide portion mounted on the motor shaft, a composite blade portion and a flexible and retractable guide vane on the hub, and an outflow blade between the upper wheel cover and the lower wheel cover, which are arranged in sequence along the flow path; the upper wheel cover comprises a buffer cavity section and an upper wheel cover outlet section connected in sequence, the buffer cavity section comprises an axial buffer inlet, a buffer cavity and a composite blade side buffer outlet; the composite blade section comprises a first blade mounted on the hub, a blade ring fixedly connected to the outer side of the first blade, and a first blade mounted on the outer side of the blade ring Two blades, wherein the tip of the second blade is located in the buffer cavity, the root of the blade is located in the main channel, and there is a flow gap between the blade ring and the upper wheel cover; in the cross-sectional view of the center axis of the second blade, the cross-sectional length of the second blade in the buffer cavity is 6 to 10 times the cross-sectional length in the main channel, the impeller inlet radius is R, and the flow gap size is (0.05 to 0.2) R. The setting of the above-mentioned buffer cavity effectively maintains the stability of the fan inlet flow, eliminates the inlet vortex phenomenon, steadily improves the uniformity of the inlet airflow speed distribution, reduces the loss of pressure fluctuation, and avoids the fan from surging due to sudden airflow changes. The position of the second blade and the setting of the gap more effectively improve the inlet efficiency and the stability of the inlet flow.

[0022] 2. In order to solve the problem of impeller imbalance caused by long-term wear of the fan, the present invention adopts a flexible retractable guide vane that can expand and contract and bend in the flow channel between the composite blade part and the outflow blade to change the position and structural size of the flexible retractable guide vane to balance the impeller. At the same time, a control unit and a position sensor are specifically adopted, wherein the position sensor monitors the position information of the flexible retractable guide vane relative to the predetermined reference position and the blade structural size information in real time; the control unit adjusts the position and structural size of the flexible retractable guide vane in real time according to the real-time working condition of the variable frequency motor and the feedback signal of the position sensor to optimize the flow diversion performance, and the flexible retractable guide vane is made of carbon fiber reinforced composite material or memory alloy material; the above structure sets the state of the impeller to an active dynamic balancing system through the dual functions of airflow regulation and mechanical protection, effectively maintains the symmetry of the airflow, reduces the fluctuation amplitude of the radial force and axial force of the impeller, and reduces aerodynamic imbalance.

[0023] 3. In order to reduce the impact of dust corrosion and other factors on the noise directly generated by the impeller, the present invention optimizes the inlet flow path and provides a guide part, including a first guide ring fixedly connected to the motor shaft, a second guide ring, and a connecting blade connecting the first guide ring and fixing the second guide ring, wherein the connecting blade is a backward inclined blade; the first guide ring includes a horizontal inlet ring section and a first inclined ring section, and the axis of the horizontal inlet ring section is collinear with the axis of the motor shaft; the second guide ring includes a vertical inlet ring section and a second inclined ring section, and the plane where the vertical inlet ring section is located is perpendicular to the axis of the motor shaft; the first inclined ring section and the second inclined ring section are parallel to each other in space, and the distance between the two is H = (0.2 ~ 0.5) R, where R is the impeller inlet radius; the angle A between the first inclined ring section, the second inclined ring section and the axis of the motor shaft is 30° ~ 60°. The setting of the first guide ring and the second guide ring organizes and re-optimizes the inlet airflow in the preset flow channel, effectively maintaining the flow state at the inlet; the setting of the backward inclined blades also reduces impact loss, improves energy conversion efficiency, and effectively controls vibration and noise; the mutual structure between the first inclined ring segment and the second inclined ring segment directly affects the efficiency and stability performance of the fan inlet. The present invention focuses on optimizing the associated fusion size and structure between the first inclined ring segment and the second inclined ring segment, which is beneficial to the suppression of turbulence and the control of resonance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the fan structure of the prior art;

[0025] Figure 2 It is a schematic diagram of a double-roll granulator in the prior art;

[0026] Figure 3 is a schematic diagram of a radial cross-section of a fan impeller of the present invention;

[0027] Figure 4 is a schematic diagram of the flexible retractable guide vane of the present invention in one operating state;

[0028] Figure 5 It is a schematic diagram of the flexible and retractable guide vane of the present invention in another operating state.

[0029] In the figure: upper wheel cover 1, lower wheel cover 2, motor shaft 3, hub 4, guide part 5, composite blade part 6, flexible retractable guide vane 7, outflow blade 8, frequency conversion motor 9, control unit 10, position sensor 13, buffer chamber section 11, upper wheel cover outlet section 12, axial buffer inlet 111, buffer chamber 112, composite blade side buffer outlet 113, first guide ring 51, connecting blade 52, second guide ring 53, first blade 61, blade ring 62, second blade 63, impeller inlet radius R, distance H between the first inclined ring segment and the second inclined ring segment, angle A between the first inclined ring segment, the second inclined ring segment and the motor shaft centerline. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] The present invention will be described in further detail below with reference to the accompanying drawings.

[0032] like Figure 1-5 As shown, a multi-dimensional composite fan includes a volute, a variable frequency motor 9 and a multi-dimensional composite centrifugal impeller, the centrifugal impeller includes an upper wheel cover 1, a lower wheel cover 2, and a hub 4; a variable frequency motor 9 is provided at the rear end of the volute, the centrifugal impeller is arranged in the volute, and the variable frequency motor 9 is connected to the centrifugal impeller hub 4 through a motor shaft 3; it is characterized in that: the centrifugal impeller also includes a guide portion 5 installed on the motor shaft 3, a composite blade portion 6 and a flexible and retractable guide vane 7 on the hub 4, and an outflow blade 8 between the upper wheel cover 1 and the lower wheel cover 2, which are arranged in sequence along the flow path direction; the upper wheel cover 1 includes a buffer cavity section 11 and an upper wheel cover outlet section connected in sequence 12. The buffer cavity section 11 includes an axial buffer inlet 111, a buffer cavity 112 and a composite blade side buffer outlet 113; the composite blade portion 6 includes a first blade 61 mounted on the hub 4, a blade ring 62 fixedly connected to the outer side of the first blade 61, and a second blade 63 mounted on the outer side of the blade ring 62, wherein the tip of the second blade 63 is located in the buffer cavity 112, the root of the blade is located in the main flow channel, and there is a flow gap between the blade ring 62 and the upper wheel cover 1; the flexible and retractable guide vane 7 can be extended and bent in the flow channel between the composite blade portion 6 and the outflow blade 8 to change the position and structural size of the flexible and retractable guide vane 7.

[0033] Furthermore, it also includes a control unit 10 and a position sensor 13, wherein the position sensor 13 monitors the position information and blade structural dimension information of the flexible retractable guide vane 7 relative to a predetermined reference position in real time; the control unit 10 adjusts the position and structural dimension of the flexible retractable guide vane 7 in real time according to the real-time working condition of the variable frequency motor 9 and the feedback signal of the position sensor 13 to optimize the flow diversion performance.

[0034] Furthermore, the flexible and retractable guide vanes 7 are made of carbon fiber reinforced composite material or memory alloy material.

[0035] Furthermore, the impeller inlet radius is R, wherein the flow gap size is (0.05-0.2)R.

[0036] Furthermore, in a cross-sectional view along the central axis of the second blade 63 , the cross-sectional length of the second blade 63 in the buffer cavity 112 is 6 to 10 times the cross-sectional length of the second blade 63 in the main flow channel.

[0037] Furthermore, the buffer cavity 112 is a fan-shaped or rectangular structure.

[0038] Furthermore, the guide part 5 adopts a double guide ring structure, which includes a first guide ring 51 fixedly connected to the motor shaft 3, a second guide ring 53, and a connecting blade 52 connecting the first guide ring 51 and fixing the second guide ring 53, wherein the connecting blade 52 is a backward inclined blade.

[0039] Furthermore, the first guide ring 51 includes a horizontal inlet ring segment and a first inclined ring segment, and the axis of the horizontal inlet ring segment is collinear with the axis of the motor shaft 3 .

[0040] Furthermore, the second guide ring 53 includes a vertical inlet ring segment and a second inclined ring segment, and the plane where the vertical inlet ring segment is located is perpendicular to the axis of the motor shaft 3.

[0041] Furthermore, the first inclined ring segment and the second inclined ring segment are parallel to each other in space, and the distance between them is H=(0.2-0.5)R, where R is the impeller inlet radius.

[0042] Furthermore, the included angle A between the first inclined ring segment, the second inclined ring segment and the axis of the motor shaft 3 is 30° to 60°.

[0043] A double-roller granulator comprises a frame, a hopper arranged on the frame, and a pair of granulating rollers located below the hopper. The granulating rollers are rotatably connected to the frame and driven by a driving device. The machine is characterized in that a fan dust removal system is also provided, and the fan dust removal system comprises a fan, a dust hood, a dust collecting box and a filtering device; the dust hood is arranged above and on both sides of the granulating roller, the dust hood is connected to the air inlet of the fan through a pipe, and the air outlet of the fan is connected to the dust collecting box, and a filtering structure is provided in the dust collecting box; the fan is a multi-dimensional composite fan.

[0044] In the prior art, conventional fans are used under special working conditions, such as in dust removal equipment, and dust accumulation causes blockage, which in turn affects the air volume and air pressure of the fan and increases energy consumption. To address the above problems, the present invention adopts a centrifugal impeller comprising a guide portion mounted on the motor shaft, a composite blade portion and a flexible and retractable guide vane on the hub, and an outflow blade between the upper wheel cover and the lower wheel cover, which are arranged in sequence along the flow path; the upper wheel cover comprises a buffer cavity section and an upper wheel cover outlet section connected in sequence, the buffer cavity section comprises an axial buffer inlet, a buffer cavity and a composite blade side buffer outlet; the composite blade section comprises a first blade mounted on the hub, a blade ring fixedly connected to the outer side of the first blade, and a second blade mounted on the outer side of the blade ring blades, wherein the tip of the second blade is located in the buffer cavity, the root of the blade is located in the main channel, and there is a flow gap between the blade ring and the upper wheel cover; in the cross-sectional view of the center axis of the second blade, the cross-sectional length of the second blade in the buffer cavity is 6 to 10 times the cross-sectional length in the main channel, the impeller inlet radius is R, and the flow gap size is (0.05 to 0.2) R. The setting of the above-mentioned buffer cavity effectively maintains the stability of the fan inlet flow, eliminates the inlet vortex phenomenon, steadily improves the uniformity of the inlet airflow speed distribution, reduces the loss of pressure fluctuation, and avoids the fan from surging due to sudden airflow changes. The position of the second blade and the setting of the gap more effectively improve the inlet efficiency and the stability of the inlet flow.

[0045] In order to solve the problem of impeller imbalance caused by long-term wear of the fan, the present invention adopts a flexible retractable guide vane that can expand and contract and bend in the flow channel between the composite blade part and the outflow blade to change the position and structural size of the flexible retractable guide vane to balance the impeller. At the same time, a control unit and a position sensor are specifically adopted, wherein the position sensor monitors the position information and blade structural size information of the flexible retractable guide vane relative to the predetermined reference position in real time; the control unit adjusts the position and structural size of the flexible retractable guide vane in real time according to the real-time working condition of the variable frequency motor and the feedback signal of the position sensor to optimize the flow diversion performance, and the flexible retractable guide vane is made of carbon fiber reinforced composite material or memory alloy material; the above structure sets the state of the impeller to an active dynamic balancing system through the dual functions of airflow regulation and mechanical protection, effectively maintains the symmetry of the airflow, reduces the fluctuation amplitude of the radial force and axial force of the impeller, and reduces aerodynamic imbalance.

[0046] In order to reduce the impact of dust corrosion and other factors on the noise directly generated by the impeller, the present invention optimizes the inlet flow path and provides a guide part, including a first guide ring fixedly connected to the motor shaft, a second guide ring, and a connecting blade connecting the first guide ring and fixing the second guide ring, wherein the connecting blade is a backward inclined blade; the first guide ring includes a horizontal inlet ring section and a first inclined ring section, and the axis of the horizontal inlet ring section is collinear with the axis of the motor shaft; the second guide ring includes a vertical inlet ring section and a second inclined ring section, and the plane where the vertical inlet ring section is located is perpendicular to the axis of the motor shaft; the first inclined ring section and the second inclined ring section are parallel to each other in space, and the distance between the two is H = (0.2 ~ 0.5) R, where R is the impeller inlet radius; the angle A between the first inclined ring section, the second inclined ring section and the axis of the motor shaft is 30° ~ 60°. The setting of the first guide ring and the second guide ring organizes and re-optimizes the inlet airflow in the preset flow channel, effectively maintaining the flow state at the inlet; the setting of the backward inclined blades also reduces impact loss, improves energy conversion efficiency, and effectively controls vibration and noise; the mutual structure between the first inclined ring segment and the second inclined ring segment directly affects the efficiency and stability performance of the fan inlet. The present invention focuses on optimizing the associated fusion size and structure between the first inclined ring segment and the second inclined ring segment, which is beneficial to the suppression of turbulence and the control of resonance.

[0047] The above-mentioned embodiments are illustrative of the present invention, not limiting thereof. It is understood that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-dimensional composite fan, comprising a volute, a variable frequency motor (9) and a multi-dimensional composite centrifugal impeller, wherein the centrifugal impeller comprises an upper wheel cover (1), a lower wheel cover (2) and a hub (4); a variable frequency motor (9) is provided at the rear end of the volute, the centrifugal impeller is arranged in the volute, and the variable frequency motor (9) is connected to the centrifugal impeller hub (4) via a motor shaft (3); and characterized in that: The centrifugal impeller further comprises a flow guide portion (5) mounted on a motor shaft (3), a composite blade portion (6) and a flexible and retractable guide vane (7) on a hub (4), and an outflow blade (8) between an upper wheel cover (1) and a lower wheel cover (2), which are sequentially arranged along the flow path direction; the upper wheel cover (1) comprises a buffer cavity section (11) and an upper wheel cover outlet section (12) connected in sequence; the buffer cavity section (11) comprises an axial buffer inlet (111), a buffer cavity (112), and a composite blade side buffer outlet (113); the composite blade portion (6) comprises a buffer cavity section (111) and a buffer cavity section (112) arranged in sequence; A first blade (61) is mounted on a hub (4), a blade ring (62) fixedly connected to the outside of the first blade (61), and a second blade (63) is mounted on the outside of the blade ring (62), wherein the tip of the second blade (63) is located in a buffer cavity (112), the root of the blade is located in a main flow channel, and a flow gap exists between the blade ring (62) and the upper wheel cover (1); and the flexible and retractable guide vane (7) can be retracted and bent in the flow channel between the composite blade portion (6) and the outflow blade (8) to change the position and structural size of the flexible and retractable guide vane (7).

2. A multi-dimensional composite fan according to claim 1, characterized in that: The invention also includes a control unit (10) and a position sensor (13), wherein the position sensor (13) monitors the position information of the flexible and retractable guide vanes (7) relative to a predetermined reference position and the blade structure and size information in real time; the control unit (10) adjusts the position and structure and size of the flexible and retractable guide vanes (7) in real time according to the real-time working condition of the variable frequency motor (9) and the feedback signal of the position sensor (13) to optimize the flow guiding performance.

3. A multi-dimensional composite fan according to claim 2, characterized in that: The flexible and retractable guide vane (7) is made of carbon fiber reinforced composite material or memory alloy material.

4. The multi-dimensional composite fan according to claim 1, characterized in that: The impeller inlet radius is R, and the flow gap size is (0.05~0.2)R.

5. The multi-dimensional composite fan according to claim 1, characterized in that: In a cross-sectional view of the center axis of the second blade (63), the cross-sectional length of the second blade (63) in the buffer cavity (112) is 6 to 10 times the cross-sectional length in the main flow channel.

6. The multi-dimensional composite fan according to claim 1, characterized in that: The buffer cavity (112) is a fan-shaped or rectangular structure.

7. The multi-dimensional composite fan according to claim 1, characterized in that: The guide portion (5) adopts a double guide ring structure, comprising a first guide ring (51) fixedly connected to the motor shaft (3), a second guide ring (53), and a connecting blade (52) connecting the first guide ring (51) and fixing the second guide ring (53), wherein the connecting blade (52) is a backward-inclined blade.

8. The multi-dimensional composite fan according to claim 7, characterized in that: The first guide ring (51) comprises a horizontal inlet ring section and a first inclined ring section, and the axis center line of the horizontal inlet ring section is collinear with the axis center line of the motor shaft (3).

9. The multi-dimensional composite fan according to claim 8, characterized in that: The second guide ring (53) comprises a vertical inlet ring section and a second inclined ring section, and the plane where the vertical inlet ring section is located is perpendicular to the axis of the motor shaft (3).

10. The multi-dimensional composite fan according to claim 9, characterized in that: The first inclined ring segment and the second inclined ring segment are parallel to each other in space, and the distance between them is H=(0.2-0.5)R, where R is the impeller inlet radius.

11. The multi-dimensional composite fan according to claim 10, characterized in that: The included angle A between the first inclined ring segment, the second inclined ring segment and the axis center line of the motor shaft (3) is 30° to 60°.

12. A roller granulator comprising a frame, a hopper mounted on the frame, and a pair of granulating rollers located below the hopper, wherein the granulating rollers are rotatably connected to the frame and driven by a driving device, wherein: A fan dust removal system is also provided, which includes a fan, a dust hood, a dust collecting box and a filtering device; the dust hood is arranged above and on both sides of the granulation roller, and the dust hood is connected to the air inlet of the fan through a pipe, and the air outlet of the fan is connected to the dust collecting box, and a filtering structure is provided in the dust collecting box; the fan is a multi-dimensional composite fan according to any one of claims 1 to 11 above.

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