A volute assembly of an induced draft fan and an induced draft fan using the same

Abstract

The invention discloses a volute assembly of an induced draft fan and an induced draft fan using the same. The volute assembly comprises a volute body and a cover plate, which are buckled together, simplifying the installation process of the volute body and the cover plate, improving the installation efficiency of the induced draft fan, facilitating the disassembly and assembly of the volute body and the cover plate, and facilitating the later maintenance of the induced draft fan. In addition, a sealing ring is arranged between the volute body and the cover plate, which can effectively improve the sealing performance of the volute assembly; the flow channel surrounded by the volute body and the cover plate is designed as an air flow channel with a smooth outer side, which effectively reduces the impact of the airflow on the volute wall surface, makes the airflow flow smoother, and makes the airflow pressure distribution in the flow channel more uniform; in addition, starting from the volute tongue portion and turning along the wind wheel to the volute exhaust port, the cross-sectional area of ​​the flow channel gradually increases, preventing the generation of peeling loss caused by the sudden increase in the cross-sectional area of ​​the airflow, and can reduce surging, improve the operating efficiency of the whole machine, and reduce the noise and vibration of the whole machine.

Description

Technical Field

[0001] The invention relates to an induced draft fan volute assembly and an induced draft fan using the induced draft fan volute assembly. Background Art

[0002] The structure of the existing volute assembly is as follows Figure 1 As shown, it includes a volute body 20A and a cover plate 10A. The cover plate 10A is designed as a circular ring plate. A groove for installing the cover plate 10A is provided at one end of the volute body 20A. The cover plate 10A is locked on the volute body 20A by a plurality of screws. The structure is simple, but since the installation of the cover plate needs to be locked by a plurality of screws, the installation process is cumbersome, which reduces the installation efficiency of the induced draft fan. Moreover, in the later maintenance of the induced draft fan, the disassembly and assembly are troublesome and inconvenient. In addition, as Figure 2 As shown, the volute inner wall surface 1A, the volute inner wall surface 2A and the volute inner wall surface 3A of the volute assembly form a flow channel, and the volute inner wall surface 1A, the volute inner wall surface 2A and the volute inner wall surface 3A are all planes, wherein the volute inner wall surface 1A and the volute inner wall surface 3A and the volute inner wall surface 2A and the volute inner wall surface 3A are basically designed to be perpendicular to each other, and the intersection of the volute inner wall surface 2A and the volute inner wall surface 3A is a small fillet, and the intersection of the volute inner wall surface 1A and the volute inner wall surface 3A is a right angle, so that the volume The airflow generated by the wind wheel can easily collide with the wall of the volute, resulting in poor airflow and uneven airflow pressure distribution in the flow channel. In addition, since the distance between the three surfaces and the wind wheel remains unchanged, the wind outlet area of ​​the wind wheel remains unchanged, resulting in low efficiency during the operation of the fan. The air outlet area suddenly increases when the air flows out of the wind wheel outlet, which will cause a large stripping loss of the airflow, resulting in sudden changes in airflow velocity and pressure, which can easily cause surging and large rotation noise, resulting in low overall efficiency and causing noise and vibration of the entire machine. Summary of the invention

[0003] The purpose of the present invention is to provide an induced draft fan volute assembly and an induced draft fan using the same, which can solve the technical problem in the prior art that the volute body and the cover plate need to be locked together by a number of screws, making the installation and disassembly processes cumbersome and reducing the installation efficiency of the induced draft fan.

[0004] Another object of the present invention is to provide an induced draft fan volute assembly and an induced draft fan using the same, which can solve the technical problem in the prior art that the airflow generated by the impeller easily collides with the volute wall, causing unsmooth airflow and uneven airflow pressure distribution in the flow channel.

[0005] The purpose of the present invention is achieved through the following technical solutions.

[0006] An object of the present invention is to provide a volute assembly of an induced draft fan, comprising a volute body, a cover plate and a sealing ring, wherein:

[0007] The volute body comprises a top plate and a side panel protruding axially from the edge of the top plate, the top plate and the side panel enclose a cavity, an exhaust duct is arranged on the side panel, the exhaust duct is connected to the cavity, and a plurality of blocks are arranged at intervals on the bottom periphery of the side panel;

[0008] The cover plate comprises a bottom plate and an annular sleeve surrounding the outside of the bottom plate, the bottom of the annular sleeve protrudes with a flange, the outer periphery of the flange is provided with a plurality of buckles at intervals, a sealing ring is sleeved on the outside of the annular sleeve, and the sealing ring is supported on the flange;

[0009] The shape of the side panel matches that of the annular sleeve. When the cover is installed on the volute body, the annular sleeve is nested in the side panel. The block and the buckle are engaged to lock the cover on the volute body. The bottom end of the side panel and the flange squeeze the sealing ring to achieve a sealing effect.

[0010] Preferably, the flange includes a radially protruding first flange and a second flange protruding from the edge of the first flange. The first flange, the second flange and the outer wall of the annular sleeve form a groove, and the sealing ring is nested in the groove. A boss is provided at the bottom end of the side panel, and the boss is embedded in the groove to squeeze the sealing ring.

[0011] Preferably, the bottom plate is located in the middle of the annular sleeve, and a first arc surface transition is adopted at the junction between the inner surface of the bottom plate and the inner wall of the annular sleeve.

[0012] Preferably, a second arc surface is used for transition at the joint between the top plate and the side panel, and a combination of the first arc surface, the inner wall of the side panel and the second arc surface forms a waist-shaped surface so that the volute body and the cover plate form a smooth airflow channel on the outside, and the airflow channel gradually increases from the volute tongue to the air outlet.

[0013] Preferably, a notch is dug out at a position of the annular sleeve close to the exhaust duct, and the notch forms an arc shape when viewed from the outlet of the exhaust duct toward the cavity.

[0014] Preferably, a guide slope is arranged on the bottom plate behind the notch.

[0015] Preferably, the annular sleeve behind the exhaust duct includes a long plane plate and a short plane plate, the long plane plate and the short plane plate are transitioned through a third arc surface, and the notches are arranged on the long plane plate, the short plane plate and the third arc surface.

[0016] Another object of the present invention is to provide an induced draft fan, comprising a volute assembly, a motor and a wind wheel, wherein the volute assembly is the volute assembly described above, the motor is mounted on the top of the volute assembly, and the front end of the motor's rotating shaft extends into the volute assembly and is installed together with the wind wheel.

[0017] Preferably, the wind wheel includes a wheel disc and a plurality of blades protruding from one end face of the wheel disc, and the outer edge of the wheel disc and the outer edges of the plurality of blades are both provided with arc segments, and the arc segments are designed to bend from the cover plate of the volute assembly toward the volute body of the volute assembly.

[0018] Preferably, the plurality of blades are unevenly distributed on the end surface of the wheel disc.

[0019] Compared with the prior art, the present invention has the following effects:

[0020] 1) The cover plate of the present invention comprises a base plate and an annular sleeve surrounding the outer side of the base plate, the bottom of the annular sleeve protrudes with a flange, and a plurality of buckles are arranged at intervals on the outer periphery of the flange, a sealing ring is sleeved on the outer side of the annular sleeve, and the sealing ring is supported on the flange; the side panel matches the shape of the annular sleeve, and when the cover plate is installed on the volute body, the annular sleeve is nested in the side panel, and the block and the buckle are engaged to lock the cover plate on the volute body, and the bottom end of the side panel and the flange squeeze the sealing ring to achieve a sealing effect, and the volute body and the cover plate are installed together by buckling, which simplifies the installation process of the volute body and the cover plate, improves the installation efficiency of the induced draft fan, facilitates the disassembly and assembly of the volute body and the cover plate, and facilitates the later maintenance of the induced draft fan. In addition, a sealing ring is arranged between the volute body and the cover plate, which can effectively improve the sealing of the volute assembly.

[0021] 2) By designing the flow channel surrounded by the volute body and the cover plate into an air flow channel with a smooth outer side, the impact of the airflow on the volute wall is effectively reduced, the airflow flows more smoothly, and the pressure distribution of the airflow in the flow channel is more uniform; in addition, starting from the volute tongue and turning along the wind wheel to the volute exhaust port, the cross-sectional area of ​​the flow channel gradually increases, so that the air outlet area gradually increases after the airflow comes out from the wind wheel, which can effectively prevent the sudden increase in the cross-sectional area of ​​the airflow and cause the peeling loss, and effectively reduce the surging flow. At the same time, it can achieve the effect of improving the operating efficiency of the whole machine and reducing the noise and vibration of the whole machine.

[0022] 3) Other advantages of the present invention are described in detail in the embodiment section. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a stereoscopic diagram of a volute assembly provided for the prior art;

[0024] Figure 2 It is a schematic diagram of the internal structure of the volute assembly provided by the prior art;

[0025] Figure 3 is an exploded view of a volute assembly provided for implementation of the present invention;

[0026] Figure 4 is an exploded view of the volute assembly from another angle provided for the first embodiment of the present invention;

[0027] Figure 5 is a top view of a volute assembly provided for implementation of the present invention;

[0028] Figure 6 Is for Figure 5 A cross-sectional view of the AA provided;

[0029] Figure 7 Is for Figure 6 An enlarged view of part B is provided;

[0030] Figure 8 is a front view of a volute assembly provided for implementation of the present invention;

[0031] Fig. 9 is a stereoscopic diagram of a volute body provided for implementation of the present invention;

[0032] Fig.10 is a top view of a volute body provided for implementation of the present invention;

[0033] Fig.11 is a front view of a cover plate provided for implementation of the present invention;

[0034] Fig.12 Is for Fig.11 A cross-sectional view of the CC provided;

[0035] Fig.13 is a three-dimensional diagram of a cover plate provided for implementation of the present invention;

[0036] Fig.14 is a rear view of a cover plate provided for implementation of the present invention;

[0037] Fig.15 Is for Fig.14 A cross-sectional view of the DD provided;

[0038] Fig.16 is a three-dimensional diagram of an induced draft fan provided for implementation 2 of the present invention;

[0039] Fig.17 is an exploded view of an induced draft fan provided for implementation 2 of the present invention;

[0040] Fig.18 This is a front view of the induced draft fan provided for the second embodiment of the present invention;

[0041] Fig.19 Is for Fig.18 A cross-sectional view of the EE provided;

[0042] Fig. 20 is a three-dimensional diagram of a wind wheel provided for implementation 2 of the present invention;

[0043] Fig.21It is a schematic diagram of the structure of the wind wheel provided for the second embodiment of the present invention. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0045] like Figures 3 to 7 , Figures 9 to 12 As shown, the present embodiment provides a volute assembly of an induced draft fan, comprising a volute body 1, a cover plate 2 and a sealing ring 3, wherein: the volute body 1 comprises a top plate 11 and a side panel 12 axially protruding from the edge of the top plate 11, the top plate 11 and the side panel 12 enclose a cavity 100, an exhaust duct 13 is arranged on the side panel 12, the exhaust duct 13 is connected to the cavity 100, and a plurality of clamping blocks 14 are arranged at intervals on the outer periphery of the bottom of the side panel 12; the cover plate 2 comprises a bottom plate 21 and an annular sleeve 22 surrounding the outer side of the bottom plate 21, a flange 23 protrudes from the bottom of the annular sleeve 22, and a plurality of buckles 24 are arranged at intervals on the outer periphery of the flange 23, and a plurality of buckles 24 are arranged on the annular sleeve 2 2 is covered with a sealing ring 3, and the sealing ring 3 is supported on the flange 23; the side panel 12 matches the shape of the annular sleeve 22. When the cover plate 2 is installed in the volute body 1, the annular sleeve 22 is nested in the side panel 12, and the block 14 and the buckle 24 are buckled to lock the cover plate 2 on the volute body 1. The bottom end of the side panel 12 and the flange 23 squeeze the sealing ring to achieve a sealing effect. The volute body 1 and the cover plate 2 are installed together in a buckled manner. The design structure is simple, and it is convenient to disassemble and assemble the volute body 1 and the cover plate 2, which is convenient for the later maintenance of the induced draft fan. In addition, a sealing ring 3 is arranged between the volute body 1 and the cover plate 2, which can effectively improve the sealing performance of the volute assembly.

[0046] The above-mentioned flange 23 includes a radially protruding first flange 231 and a second flange 232 protruding from the edge of the first flange 231. The first flange 231, the second flange 232 and the outer wall of the annular sleeve 22 form a groove 4. The sealing ring 3 is nested in the groove 4. The bottom end of the side panel 12 is provided with a boss 121. The boss 121 is embedded in the groove 4 to squeeze the sealing ring 3 and position the sealing ring 3 to prevent the sealing ring 3 from being misplaced when installing the sealing ring 3, resulting in poor sealing effect of the induced draft fan. The cooperation of the boss and the groove can effectively improve the sealing performance of the volute assembly and facilitate the installation and fixation of the sealing ring.

[0047] The above-mentioned annular sleeve 22 is nested in the side panel 12, wherein the depth of the annular sleeve 22 extending into the side panel 12 is L, and the value range of the depth L is between 16.6mm-26.6mm. Combined with the use of a sealing ring, the sealing performance of the volute assembly can be further improved, and the installation and positioning of the volute body 1 and the cover plate 2 can be facilitated.

[0048] The bottom plate 21 is located in the middle of the annular sleeve 22. The junction between the inner surface 210 of the bottom plate 21 and the inner wall of the annular sleeve 22 adopts a first arc surface 220 for transition; the junction between the top plate 11 and the side panel 12 adopts a second arc surface 15 for transition. The combination of the first arc surface 220, the inner wall of the side panel 12, and the second arc surface 15 forms a waist-shaped surface so that the volute body 1 and the cover plate 2 form a smooth airflow channel on the outside. By designing the side of the airflow channel into a smooth surface , effectively reducing the impact of the airflow on the wall of the volute, making the airflow flow smoother, and making the pressure distribution of the airflow in the flow channel more uniform; a folded cylinder portion 25 is provided on the outer surface of the bottom plate 21 protruding toward the top of the annular sleeve 22, and a through hole surrounded by the center of the folded cylinder portion 25 passes through the bottom plate 21 to form an air inlet 26 of the volute assembly, and the outer wall surface of the folded cylinder portion 25 is connected to the annular sleeve 22 through a plurality of reinforcing ribs 27, so that the strength of the cover plate 2 is enhanced.

[0049] like Fig.10 As shown, a volute tongue portion 5 is provided in the cavity 100 near the exhaust duct 13, and an air outlet 6 is formed at the tail of the exhaust duct 13. The flow path gradually increases from the volute tongue portion 5 to the air outlet 6, so that the air outlet area gradually increases after the air flow comes out from the wind wheel 2020, which can effectively prevent the stripping loss caused by the sudden increase in the cross-sectional area of ​​the air flow, and effectively reduce the surging flow. At the same time, it can achieve the effect of improving the operating efficiency of the whole machine and reducing the noise and vibration of the whole machine.

[0050] like Figure 4 and Figure 8 As shown, the annular sleeve 22 is dug out with a notch 7 near the exhaust duct 13, and the notch 7 is formed into an arc shape when viewed from the outlet of the exhaust duct 13 toward the cavity 100, so as to maintain a smooth transition between the flow channel and the exhaust duct 13; Figures 13 to 15 As shown, a guide slope 8 is provided on the bottom plate 21 behind the notch 7, extending from the inside of the annular sleeve 22 to the exhaust duct 13. The height H of the guide slope 8 gradually increases, so that the cross-sectional area of ​​the air outlet gradually increases, and the air outlet area gradually increases after the airflow comes out from the wind wheel 20, which can effectively prevent the stripping loss caused by the sudden increase in the cross-sectional area of ​​the airflow, and effectively reduce the surging flow. At the same time, it can achieve the effect of improving the operating efficiency of the whole machine and reducing the noise and vibration of the whole machine.

[0051] The annular sleeve 22 behind the exhaust duct 13 includes a long flat plate 221 and a short flat plate 222, and the long flat plate 221 and the short flat plate 222 are transitioned by a third arc surface 223. The notch 7 is arranged on the long flat plate 221, the short flat plate 222 and the third arc surface 223 to facilitate the positioning and matching installation of the annular sleeve 22 and the side panel 12.

[0052] A plurality of mounting feet 16a, 16b are also provided on the side of the volute body 1. The induced draft fan can be fixedly mounted on the load mounting plate by passing bolts through the mounting feet 16a, 16b. When the induced draft fan is mounted on the load mounting plate, additional force can be applied to the volute body 1 and the cover plate 2, so that the volute body 1 and the cover plate 2 can be better squeezed together, thereby improving the sealing of the induced draft fan. The mounting feet 16a, 16b have two different shape structures, one is a circular arc plate structure with a circular hole, and the other is a square columnar structure with a waist-shaped hole. Users can choose mounting feet 16a, 16b structures of different shapes to install the induced draft fan according to actual needs. The humanized design and diversified choices make the installation of the induced draft fan more convenient.

[0053] The volute body 1 and the cover plate 2 are both manufactured by an integral injection molding process, and have a simple structure, convenient processing, and high installation precision.

[0054] Embodiment 2:

[0055] like Fig.16 and Fig.17 As shown, this embodiment provides an induced draft fan, including a volute assembly 10, a wind wheel 20 and a motor 30. The volute assembly 10 is the volute assembly 10 described in Example 1, and the motor 30 is installed on the top of the volute assembly 10. The front end of the rotating shaft of the motor 30 extends into the volute assembly 10 and is installed together with the wind wheel 20.

[0056] like Fig.18 and Fig. 20 As shown, the wind wheel 20 includes a wheel disc 201 and a plurality of blades 202 protruding from one end face of the wheel disc 201, and the outer edges of the wheel disc 201 and the outer edges of the plurality of blades 202 are both provided with arc segments 203, and the arc segments 203 are bent from the cover plate 2 toward the volute body 1, so that the center of the air outlet of the wind wheel 20 is closer to the center of the volute air outlet 6, and the bending direction of the arc segment 203 is the same as that of the arc surface of the cover plate 2, which can effectively reduce the impact of the airflow on the volute wall, make the airflow flow smoother, and make the pressure distribution of the airflow in the flow channel more uniform.

[0057] The blades 202 are unevenly distributed on the end surface of the wheel disc 201. Preferably, the spacing between two adjacent blades 202 that are symmetrically distributed is equal; further, the maximum spacing between two adjacent blades 202 is a, and the minimum spacing between two adjacent blades 202 is b; Fig.21In a clockwise direction, first, the spacing between two adjacent blades 202 gradually decreases from a to b, and secondly, the spacing between two adjacent blades 202 gradually increases from b to a, and then, the spacing between two adjacent blades 202 gradually decreases from a to b, and finally, the spacing between two adjacent blades 202 gradually increases from b to a. The distribution of the blades 202 of the wind wheel 20 is specifically as described above. By adopting the form of unequally spaced distribution of the blades 202, the rotation noise of the induced draft fan can be effectively reduced when the wind wheel 20 provides the same air volume and pressure.

[0058] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited thereto. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention are all equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A volute assembly of an induced draft fan, comprising a volute body (1), a cover plate (2) and a sealing ring (3), wherein: The volute body (1) comprises a top plate (11) and a side panel (12) axially protruding from the edge of the top plate (11), the top plate (11) and the side panel (12) enclose a cavity (100), an exhaust duct (13) is arranged on the side panel (12), the exhaust duct (13) is communicated with the cavity (100), and a plurality of blocks (14) are arranged at intervals on the outer periphery of the bottom of the side panel (12); The cover plate (2) comprises a bottom plate (21) and an annular sleeve (22) surrounding the outside of the bottom plate (21); a flange (23) protrudes from the bottom of the annular sleeve (22); a plurality of buckles (24) are arranged at intervals on the periphery of the flange (23); a sealing ring (3) is sleeved on the outside of the annular sleeve (22); and the sealing ring (3) is supported on the flange (23); The side panel (12) and the annular sleeve (22) match in shape. When the cover plate (2) is mounted on the volute body (1), the annular sleeve (22) is nested in the side panel (12). The clamping block (14) and the buckle (24) are engaged to lock the cover plate (2) on the volute body (1). The bottom end of the side panel (12) and the flange (23) squeeze the sealing ring (3) to achieve a sealing effect. The invention is characterized in that: A notch (7) is dug out of the annular sleeve (22) near the exhaust duct (13), and the notch (7) forms an arc shape when viewed from the outlet of the exhaust duct (13) toward the cavity (100); A guide slope (8) is arranged on the bottom plate (21) behind the notch (7).

2. The induced draft fan volute assembly according to claim 1, characterized in that: The flange (23) comprises a first flange (231) protruding radially and a second flange (232) protruding from the edge of the first flange (231); the first flange (231), the second flange (232) and the outer wall of the annular sleeve (22) form a groove (4); the sealing ring (3) is nested in the groove (4); a boss (121) is provided at the bottom end of the side panel (12); the boss (121) is embedded in the groove (4) to squeeze the sealing ring (3).

3. The induced draft fan volute assembly according to claim 2, characterized in that: The bottom plate (21) is located in the middle of the annular sleeve (22), and the junction between the inner surface (210) of the bottom plate (21) and the inner wall of the annular sleeve (22) adopts a first arc surface (220) for transition.

4. The induced draft fan volute assembly according to claim 3, characterized in that: The joint between the top plate (11) and the side panel (12) is transitioned by a second arc surface (15), and the combination of the first arc surface (220), the inner wall of the side panel (12), and the second arc surface (15) forms a waist-shaped surface so that the volute body (1) and the cover plate (2) form a smooth airflow channel on the outside.

5. The induced draft fan volute assembly according to claim 1, 2, 3 or 4, characterized in that: The annular sleeve (22) behind the exhaust duct (13) comprises a long plane plate (221) and a short plane plate (222), the long plane plate (221) and the short plane plate (222) are transitioned through a third arc surface (223), and the notch (7) is arranged on the long plane plate (221), the short plane plate (222) and the third arc surface (223).

6. An induced draft fan, comprising a volute assembly (10), a fan wheel (20) and a motor (30), characterized in that: The volute assembly (10) is a volute assembly as described in any one of claims 1 to 5, the motor (30) is installed on the top of the volute assembly (10), and the front end of the rotating shaft of the motor (30) extends into the volute assembly (10) and is installed together with the wind wheel (20).

7. The induced draft fan according to claim 6, characterized in that: The wind wheel (20) comprises a wheel disc (201) and a plurality of blades (202) protruding from one end surface of the wheel disc (201); the outer edges of the wheel disc (201) and the outer edges of the plurality of blades (202) are both provided with arc segments (203); the arc segments (203) are designed to bend from the cover plate (2) of the volute assembly (10) toward the volute body (1) of the volute assembly (10).

8. The induced draft fan according to claim 7, characterized in that: A plurality of blades (202) are unevenly distributed on the end surface of the wheel disc (201).

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