Small-size induced draft fan
By optimizing the compact design, brushless DC motor, and static pressure ring structure, the problems of large induced draft fan size and low static pressure at the pressure tapping port were solved, achieving efficient and accurate signal extraction and improved static pressure efficiency.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ZHONGSHAN BROAD OCEAN
- Filing Date
- 2025-05-27
- Publication Date
- 2026-07-02
AI Technical Summary
Existing induced draft fans are large in size and have a large load volume. They are inefficient, cannot be infinitely speed-regulated, and have low static pressure at the pressure tapping port, making signal extraction difficult.
It adopts a compact design, uses a DC brushless motor, and sets up an inner and outer static pressure ring to form a static pressure detection groove. The impeller is designed with a difference in the inner tangent diameter of the negative pressure blades. The air inlet of the volute cover is off-center and equipped with an annular air guide ring to improve static pressure efficiency and signal extraction accuracy.
It achieves a compact and efficient induced draft fan design, improves the static pressure at the pressure tap, makes signal extraction easier and more accurate, and allows for stepless speed regulation of the motor, reducing wind resistance and improving static pressure efficiency.
Smart Images
Figure CN2025097397_02072026_PF_FP_ABST
Abstract
Description
A small-volume induced draft fan Technical Field
[0001] This application relates to a small-volume induced draft fan. Background Technology
[0002] Our company currently has a Model 90 induced draft fan, the specific structure of which can be found in the patent patent number: 201910371234.X, patent name: Induced Draft Fan Scroll Assembly and Invention Patent of Induced Draft Fan. It has the following shortcomings: 1. The existing Model 90 induced draft fan scroll is very large, resulting in a large load volume; 2. It uses an AC motor, which has low efficiency, low speed, and cannot be infinitely speed-adjusted; 3. Low static pressure efficiency; 4. Low static pressure at the pressure tapping port, making it difficult to extract signals. Summary of the Invention
[0003] The purpose of this application is to provide a small-volume induced draft fan to solve the technical problem in the prior art where the static pressure at the pressure tapping port of the induced draft fan is low, leading to difficulties in signal extraction.
[0004] A further objective of this application is to provide a small-volume induced draft fan, which solves the technical problem that existing induced draft fans are large in size, resulting in a large load volume and low efficiency.
[0005] The technical solution of this application is implemented as follows:
[0006] A small-volume induced draft fan includes a volute, a impeller, a motor, a pressure measuring interface device, and a volute cover plate. The volute cover plate is installed at the bottom of the volute, forming a cavity in the middle. The volute has an air outlet communicating with the cavity, and the volute cover plate has an air inlet communicating with the cavity. The motor is installed on the outside of the top of the volute. A shaft hole is opened on the top plate of the volute, through which the motor shaft passes and extends into the cavity to connect with the impeller. The pressure measuring interface device is installed on the top of the volute. The key feature is that an inner static pressure ring and an outer static pressure ring are protruding from the outer periphery of the shaft hole and on the top plate. The inner and outer static pressure rings are located inside the cavity. The outer static pressure ring is fitted around the inner static pressure ring, forming a static pressure detection groove in the middle. A pressure measuring through hole is provided on the top plate, located at the top of the detection groove. The pressure measuring interface device is installed at the position of the pressure measuring through hole to detect the internal static pressure of the volute.
[0007] The aforementioned inner static pressure ring is higher than the outer static pressure ring.
[0008] The aforementioned wind turbine includes an upper rotor, a lower rotor, and rotor blades located between the upper and lower rotors. Several negative pressure blades protrude from the top of the upper rotor. The inner tangent diameter of the negative pressure blades is larger than the outer diameter of the inner static pressure ring, and the inner tangent diameter of the negative pressure blades is smaller than the diameter of the outer static pressure ring. The top of the negative pressure blades is higher than the bottom of the inner static pressure ring, and the top of the negative pressure blades is lower than the bottom of the outer static pressure ring, forming a high static pressure zone in the static pressure detection groove.
[0009] The air inlet of the aforementioned volute cover is off-center.
[0010] The edge of the air inlet of the aforementioned volute cover plate protrudes upwards with an annular air guide ring, which is located inside the cavity and extends into the air inlet of the impeller.
[0011] The cross-section of the aforementioned annular air guide ring is arc-shaped.
[0012] The motors mentioned above are brushless DC motors.
[0013] The aforementioned motor includes a motor body and a motor controller, with the motor controller mounted on top of the motor body.
[0014] The aforementioned motor body includes a front cover, a rear cover, a stator assembly, and a rotor assembly. Several mounting feet extend from the edge of the front cover, through which the motor is mounted on the top of the volute.
[0015] Compared with the prior art, this application has the following advantages:
[0016] 1. The volute of this application has an inner static pressure ring and an outer static pressure ring protruding from the outer periphery of the shaft hole and the top plate. The inner and outer static pressure rings are located inside the cavity. The outer static pressure ring is sleeved around the inner static pressure ring and forms a static pressure detection groove in the middle. The top plate is provided with a pressure measuring through hole, which is located at the top of the detection groove. The pressure measuring interface device is installed at the position of the pressure measuring through hole to detect the internal static pressure of the volute. The arrangement of the outer static pressure ring, the inner static pressure ring, and the static pressure detection groove is conducive to forming a high static pressure area in the static pressure detection groove, increasing the static pressure at the pressure tap of the pressure measuring through hole, and making signal extraction easier and more accurate.
[0017] 2. The wind turbine includes an upper disk, a lower disk, and wind turbine blades located between the upper and lower disks. Several negative pressure blades protrude from the top of the upper disk. The inner tangent diameter of the negative pressure blades is larger than the outer diameter of the inner static pressure ring, and the inner tangent diameter of the negative pressure blades is smaller than the diameter of the outer static pressure ring. The top of the negative pressure blades is higher than the bottom of the inner static pressure ring, and the top of the negative pressure blades is lower than the bottom of the outer static pressure ring. This is more conducive to forming a high static pressure zone in the static pressure detection groove, further improving the static pressure at the pressure tap of the pressure measuring through hole.
[0018] 3. Other advantages of this application are described in detail in the Embodiments section. Attached Figure Description
[0019] Figure 1 is a perspective view of this application from one angle;
[0020] Figure 2 is a perspective view of this application after omitting the impeller and volute cover plate;
[0021] Figure 3 is an exploded view of this application;
[0022] Figure 4 is a top view of this application;
[0023] Figure 5 is a BB cross-sectional view of Figure 4. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0025] As shown in Figures 1 to 5, this embodiment provides a small-volume induced draft fan, including a volute 1, an impeller 2, a motor 3, a pressure measuring interface device 4, and a volute cover plate 5. The volute cover plate 5 is installed at the bottom of the volute 1, forming a cavity 10 in the middle. The volute 1 has an air outlet 11 communicating with the cavity 10, and the volute cover plate 5 has an air inlet 51 communicating with the cavity 10. The motor 3 is installed on the outside of the top of the volute 1. A shaft hole 13 is opened on the top plate 12 of the volute 1, and the rotating shaft 30 of the motor 3 passes through the shaft hole 13 and extends into the cavity 10 to interact with the airflow. Wheels 2 are connected together, and pressure measuring interface device 4 is installed on the top of volute 1. The feature is that an inner static pressure ring 14 and an outer static pressure ring 15 are protruding on the outer periphery of shaft hole 13 and top plate 12. The inner static pressure ring 14 and the outer static pressure ring 15 are located inside cavity 10. The outer static pressure ring 15 is sleeved on the outer periphery of inner static pressure ring 14 and forms a static pressure detection groove 16 in the middle. The top plate 12 is provided with a pressure measuring through hole 17, which is located on the top of detection groove 16. The pressure measuring interface device 4 is installed at the position of pressure measuring through hole 17 to detect the internal static pressure of volute 1.
[0026] The volute of this application has an inner static pressure ring and an outer static pressure ring protruding from the outer periphery of the shaft hole and the top plate. The inner and outer static pressure rings are located inside the cavity. The outer static pressure ring is sleeved around the inner static pressure ring and forms a static pressure detection groove in the middle. The top plate is provided with a pressure measuring through hole, which is located at the top of the detection groove. A pressure measuring interface device is installed at the position of the pressure measuring through hole to detect the internal static pressure of the volute. The arrangement of the outer static pressure ring, the inner static pressure ring, and the static pressure detection groove is conducive to forming a high static pressure area in the static pressure detection groove, increasing the static pressure at the pressure tap of the pressure measuring through hole, making signal extraction easier and more accurate.
[0027] The inner static pressure ring 14 is higher than the outer static pressure ring 15.
[0028] The aforementioned wind turbine 2 includes an upper rotor 21, a lower rotor 22, and rotor blades 23 located between the upper rotor 21 and the lower rotor 22. Several negative pressure blades 24 protrude from the top of the upper rotor 21. The inner tangent diameter of the negative pressure blades 24 is larger than the outer diameter of the inner static pressure ring 14, and smaller than the diameter of the outer static pressure ring 15. The top tip 241 of the negative pressure blades 24 is higher than the bottom tip of the inner static pressure ring 14, and lower than the bottom tip of the outer static pressure ring 15, forming a high static pressure zone in the static pressure detection groove 16. This makes signal extraction easier.
[0029] The air inlet 51 of the aforementioned volute cover 5 is off-center. This reduces air resistance and improves static pressure efficiency.
[0030] The edge of the air inlet 51 of the aforementioned volute cover plate 5 protrudes upward to form an annular air guide ring 52. The annular air guide ring 52 is located inside the cavity 10 and extends into the air inlet 21 of the impeller 2, reducing air inlet leakage and mixing, thereby reducing wind resistance and improving static pressure efficiency.
[0031] The cross-section of the aforementioned annular air guide ring 52 is arc-shaped, with a simple structure and good air guiding effect.
[0032] The aforementioned motor 3 is a DC brushless motor, which is highly efficient, has a high speed, and can be infinitely speed-adjusted.
[0033] The aforementioned motor 3 includes a motor body 3a and a motor controller 3b, with the motor controller 3b mounted on top of the motor body 3a.
[0034] The aforementioned motor body 3a includes a front cover 31, a rear cover 32, a stator assembly 33, and a rotor assembly 34. Several mounting feet 311 extend from the edge of the front cover 31, allowing the motor 3 to be mounted on the top of the volute 1 via these mounting feet 311. The structure is simple and easy to install.
[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application 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. Such 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 this application.
Claims
1. A small-volume induced draft fan, comprising a volute (1), a fan wheel (2), a motor (3), a pressure measuring interface device (4), and a volute cover plate (5), wherein the volute cover plate (5) is installed at the bottom of the volute (1) and forms a cavity (10) in the middle, the volute (1) is provided with an air outlet (11) communicating with the cavity (10), the volute cover plate (5) is provided with an air inlet (51) communicating with the cavity (10), the motor (3) is installed on the outside of the top of the volute (1), a shaft hole (13) is opened on the top plate (12) of the volute (1), the rotating shaft (30) of the motor (3) passes through the shaft hole (13) and extends into the cavity (10) to be connected with the fan wheel (2), and the pressure measuring interface device (4) is installed on the top of the volute (1), characterized in that: An inner static pressure ring (14) and an outer static pressure ring (15) are protruding on the outer periphery of the shaft hole (13) and the top plate (12). The inner static pressure ring (14) and the outer static pressure ring (15) are located inside the cavity (10). The outer static pressure ring (15) is sleeved on the outer periphery of the inner static pressure ring (14) and forms a static pressure detection groove (16) in the middle. The top plate (12) is provided with a pressure measuring through hole (17). The pressure measuring through hole (17) is located at the top of the detection groove (16). The pressure measuring interface device (4) is installed at the position of the pressure measuring through hole (17) to detect the internal static pressure of the volute (1).
2. The small-volume induced draft fan according to claim 1, characterized in that: The inner static pressure ring (14) is higher than the outer static pressure ring (15).
3. A small-volume induced draft fan according to claim 2, characterized in that: The wind turbine (2) includes an upper disk (21), a lower disk (22), and wind turbine blades (23) located between the upper disk (21) and the lower disk (22). Several negative pressure blades (24) protrude from the top of the upper disk (21). The inner tangent diameter of the negative pressure blades (24) is larger than the outer diameter of the inner static pressure ring (14), and the inner tangent diameter of the negative pressure blades (24) is smaller than the diameter of the outer static pressure ring (15). The top end (241) of the negative pressure blades (24) is higher than the bottom end of the inner static pressure ring (14), and the top end (241) of the negative pressure blades (24) is lower than the bottom end of the outer static pressure ring (15), forming a high static pressure zone in the static pressure detection groove (16).
4. A small-volume induced draft fan according to claim 1, 2, or 3, characterized in that: The air inlet (51) of the volute cover (5) is off-center.
5. A small-volume induced draft fan according to claim 4, characterized in that: The edge of the air inlet (51) of the volute cover (5) protrudes upward to form an annular air guide ring (52), which is located inside the cavity (10) and extends into the air inlet (21) of the impeller (2).
6. A small-volume induced draft fan according to claim 5, characterized in that: The cross-section of the annular air guide ring (52) is arc-shaped.
7. A small-volume induced draft fan according to claim 6, characterized in that: The motor (3) is a DC brushless motor.
8. A small-volume induced draft fan according to claim 7, characterized in that: The motor (3) includes a motor body (3a) and a motor controller (3b), with the motor controller (3b) mounted on top of the motor body (3a).
9. A small-volume induced draft fan according to claim 8, characterized in that: The motor body (3a) includes a front cover (31), a rear cover (32), a stator assembly (33) and a rotor assembly (34), wherein the edge of the front cover (31) extends out a number of mounting feet (311), and the motor (3) is mounted on the top of the volute (1) by means of the mounting feet (311).