Fireproof centrifugal fan

Abstract

The utility model belongs to centrifugal fan technical field especially relates to a fireproof centrifugal fan, including the casing, the impeller of rotation setting in the casing is connected with the transmission assembly of impeller transmission, the casing is provided with the air inlet and the air outlet, fireproof intercepting component, the air inlet place detachably installed has fireproof intercepting component, fireproof intercepting component includes the intercepting board of multilayer ladder form staggered arrangement, forms the spark settlement chamber between adjacent intercepting board, all the intercepting board are provided with a plurality of guide flow through -hole, the outside of transmission assembly is equipped with the heat -proof shield, and the closed heat -proof chamber is formed between heat -proof shield and transmission assembly, and the heat -proof chamber is filled with the heat -proof material, and the outer surface of heat -proof shield is integrally formed with the radiating fin. The utility model provides a kind of fireproof centrifugal fan for effectively solving the high-temperature influence and security risk caused by spark spatter to motor around when fire.

Description

Technical Field

[0001] This utility model belongs to the field of centrifugal fan technology, and in particular relates to a fireproof centrifugal fan. Background Technology

[0002] In fields such as building fire protection, industrial plant ventilation and smoke exhaust, and emergency ventilation in flammable and explosive locations, fire-resistant centrifugal fans are key fire protection and ventilation equipment. They play an important role in exhausting toxic smoke and maintaining a stable ventilation environment in the area during a fire. Their operational reliability is directly related to the efficiency of personnel evacuation and the conduct of fire rescue work. Existing fireproof centrifugal fans mainly consist of core components such as a motor, impeller, casing, and fire damper. The motor, as the power source, provides the driving force for the high-speed rotation of the impeller, thereby enabling gas transport and discharge. Under normal operating conditions, the motor maintains its normal operating temperature through its built-in heat dissipation structure (such as a cooling fan and heat sink), ensuring stable fan operation. However, when a fire occurs, the environment around the fan changes drastically. At this time, the fan needs to operate continuously to expel the high-temperature smoke from the fire scene. This high-temperature smoke often contains a large number of incompletely burned combustible particles (such as sawdust and plastic fragments) and sparks. These sparks, after entering the fan with the airflow, are easily propelled to the area surrounding the motor by the airflow.

[0003] On the one hand, the high temperature carried by Mars itself will be directly transferred to the motor housing, causing the internal temperature of the motor to rise sharply. Key components inside the motor, such as the winding insulation layer and bearing grease, are extremely sensitive to temperature. When the temperature exceeds the tolerance threshold (generally, the insulation layer can withstand a temperature of no more than 155°C, and the bearing grease can withstand a temperature of no more than 120°C), the insulation layer will age and carbonize rapidly, leading to a short circuit in the winding. The bearing grease will melt and leak, causing dry friction in the bearing, ultimately causing the motor to stop. This will cause the fireproof centrifugal fan to lose its ventilation and smoke exhaust function, seriously hindering the exhaust of smoke and the evacuation of personnel at the fire scene. On the other hand, sparks flying near the motor also pose a safety hazard of directly igniting flammable materials around the motor. Some fireproof centrifugal fans have gaps between the motor and the casing, or the motor junction box, heat dissipation channels, and other parts lack effective fireproofing measures. Sparks may enter the motor through these gaps or ignite flammable components such as cable insulation and equipment casings around the motor, thus causing a secondary fire and expanding the scope of the fire accident. Currently, protective measures for fire-resistant centrifugal fan motors mostly focus on improving the fire resistance of the motor itself (such as using explosion-proof motors or increased safety motors) or installing simple filter structures at the fan inlet. However, while explosion-proof and increased safety motors can improve their fire resistance, they cannot effectively block the impact of external sparks and the transfer of high temperatures, and the motor still faces the risk of overheating due to external heat sources. Inlet filters can only filter larger flammable particles, and their effectiveness in intercepting small sparks is limited. Furthermore, the filters are prone to deformation and burning under high-temperature environments, thus losing their protective function. Utility Model Content

[0004] The purpose of this invention is to address the aforementioned technical problems by providing a fireproof centrifugal fan that effectively solves the high-temperature effects and safety hazards caused by sparks flying near the motor during a fire.

[0005] In view of this, the present invention provides a fireproof centrifugal fan, including a casing, an impeller rotatably disposed inside the casing, a transmission assembly connected to the impeller, and an air inlet and an air outlet. Fireproof interception component, which can be detachably installed at the air inlet. The fireproof interception component includes multiple layers of interception plates arranged in a stepped and staggered manner. A spark settling chamber is formed between adjacent interception plates. Several guide holes are opened on each interception plate. The transmission assembly is provided with a heat insulation protective cover on the outside. The heat insulation protective cover and the transmission assembly form a closed heat insulation cavity. The heat insulation cavity is filled with heat insulation material, and the outer surface of the heat insulation protective cover is integrally formed with heat dissipation fins.

[0006] In the above technical solution, the interceptor plate is further composed of a flat part and an inclined part that is inclinedly connected to the flat part. The flat part and the inclined part are alternately arranged in the vertical direction, and the flow guide hole is arranged on the inclined part.

[0007] In any of the above technical solutions, the guide hole is further described as a circular hole or an oblong hole, and the guide holes of adjacent inclined sections are staggered.

[0008] In any of the above technical solutions, a fireproof plate is further provided on the rear side of the interceptor plate, and a number of air inlets are provided on the fireproof plate, and the air inlets are connected to the guide holes; fireproof expansion strips are provided at even intervals along the length direction on the rear side of the fireproof plate.

[0009] In any of the above technical solutions, the air inlet is further provided with louvers, and the louvers are located behind the fireproof board.

[0010] In any of the above technical solutions, the transmission component further includes: Explosion-proof motor, installed inside the heat insulation cavity; The drive shaft is rotatably installed inside the housing, with one end of the drive shaft extending through the interior of the heat insulation shield. A small pulley is installed on the output shaft of the explosion-proof motor; A large pulley is mounted on the drive shaft; A flat belt is fitted between the small pulley and the large pulley.

[0011] The beneficial effects of this utility model are: 1. Through the flat and inclined sections of the stepped interception plate, and the multi-level interception system of staggered guide holes, fireproof plates, and louvers, the entire process of spark coarse filtration, fine filtration, secondary blocking, and backflow prevention is controlled. This not only avoids secondary fires caused by sparks contacting the transmission components, but also blocks backflow of fire caused by reverse airflow, significantly improving the spark interception rate.

[0012] 2. Relying on the protective combination of heat insulation cavity, heat insulation material and heat dissipation fins, plus fireproof expansion strips, it prevents the penetration of high temperature fire from the outside and prevents the leakage of internal sparks from the motor. At the same time, it assists in heat dissipation, ensuring that the transmission components do not overheat or fail in high temperature environments, and ensuring continuous and stable power transmission.

[0013] 3. The detachable interception components facilitate daily maintenance and cleaning; the fireproof expansion strip automatically seals and the louvers reverse close to adapt to sudden situations such as pressure fluctuations during a fire; the explosion-proof motor is suitable for high-risk scenarios such as flammable and explosive materials, achieving dual-condition adaptability for normal ventilation and fire emergency, taking into account both safety and practicality. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the fireproof interception component of this utility model; Figure 3 This is a partial three-dimensional structural schematic diagram of the present invention; The attached diagram is labeled as follows: 1. Housing; 2. Impeller; 3. Air inlet; 4. Air outlet; 5. Fireproof interception assembly; 51. Interception plate; 501. Flat section; 502. Inclined section; 52. Spark settling chamber; 53. Guide hole; 6. Heat insulation cover; 7. Heat insulation chamber; 8. Heat dissipation fins; 9. Fireproof plate; 10. Air inlet; 11. Fireproof expansion strip; 12. Louver; 13. Transmission assembly; 131. Explosion-proof motor; 132. Drive shaft; 133. Small pulley; 134. Large pulley; 135. Flat belt. Detailed Implementation

[0015] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0016] In the description of this application, it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. For ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items, and therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0017] Example 1: like Figures 1-3 As shown, this embodiment provides a fireproof centrifugal fan, including a casing 1, an impeller 2 rotatably disposed inside the casing 1, a transmission assembly 13 that is drively connected to the impeller 2, and an air inlet 3 and an air outlet 4 provided in the casing 1. Fireproof interception component 5, fireproof interception component 5 is detachably installed at air inlet 3. Fireproof interception component 5 includes multiple layers of interception plates 51 arranged in a stepped and staggered manner. A spark settling cavity 52 is formed between adjacent interception plates 51. Several guide holes 53 are opened on each interception plate 51. The transmission assembly 13 is provided with a heat insulation protective cover 6 on the outside. A closed heat insulation cavity 7 is formed between the heat insulation protective cover 6 and the transmission assembly 13. The heat insulation cavity 7 is filled with heat insulation material, and heat dissipation fins 8 are integrally formed on the outer surface of the heat insulation protective cover 6.

[0018] In this technical solution, a stepped interception structure is used to efficiently capture sparks in the airflow, preventing them from contacting the transmission component 13 and eliminating fire hazards; through the composite structure of the heat insulation cavity 7 and the heat dissipation fins 8, the transmission of high temperature in the fire to the transmission component 13 is blocked, while heat dissipation is assisted, ensuring that the transmission component 13 continues to operate stably under fire conditions.

[0019] Working principle: When high-temperature flue gas containing sparks enters the air inlet 3, the airflow (gaseous, low mass, and highly fluid) can flow smoothly through the guide holes 53 of the interceptor plate 51; while the sparks (solid particles, high mass, and high inertia) are difficult to follow the airflow and change direction quickly. The multi-layered, stepped, staggered interceptor plates 51 force the airflow to frequently "turn," and the sparks continuously impact the surface of the interceptor plate 51 due to inertia, gradually attenuating their kinetic energy; some sparks will fall into the spark settling chamber 52 formed by adjacent interceptor plates 51 along the airflow direction on the surface of the interceptor plate 51. The fireproof interception component 5 supports quick disassembly and assembly, facilitating regular cleaning of spark residue in the settling chamber and preventing accumulation and blockage. The closed heat insulation chamber 7 surrounding the transmission component 13 is filled with heat insulation material (such as ceramic fiber), which significantly reduces the efficiency of heat transfer from the fire scene to the transmission component 13 through the principle of heat conduction barrier; the integrated heat dissipation fins 8 on the outer surface of the heat insulation protective cover 6 quickly dissipate the heat generated by the operation of the transmission component 13 itself, as well as a small amount of heat passing through the heat insulation layer, to the outside through heat radiation and air convection, preventing heat accumulation. The enclosed environment of the insulation chamber 7 prevents sparks and smoke from directly contacting the transmission components 13, reducing the risk of mechanical wear and electrical failures, and ensuring that transmission efficiency is not affected by the fire environment. Through the collaborative design of physical spark interception and bidirectional heat flow control, the failure problem of the centrifugal fan transmission system under fire conditions is solved from two dimensions: blocking spark intrusion at the source and isolating the impact of heat damage during the process. Ultimately, this achieves long-term reliable operation of the fan in fire scenarios.

[0020] like Figure 2 As shown, in this embodiment, the optimized interceptor plate 51 is composed of a flat portion 501 and an inclined portion 502 that is inclinedly connected to the flat portion 501. The flat portion 501 and the inclined portion 502 are alternately arranged in the vertical direction, and the guide hole 53 is provided on the inclined portion 502.

[0021] In this technical solution, the flat part 501 directly blocks the straight intrusion of sparks, and the tilted part 502 guides the sparks to quickly leave the airflow and fall into the settling chamber. The guide hole 53 of the tilted part 502, combined with the tilted design, reduces the airflow turning resistance, avoids the interception component from affecting the fan exhaust efficiency due to excessive wind resistance, and at the same time reduces the risk of spark accumulation and blockage.

[0022] Working principle: The interceptor plate 51 is integrally formed by a flat part 501 (lateral blocking) and an inclined part 502 (flow guide + opening), and the flat part 501 and the inclined part 502 of the upper and lower interceptor plates 51 are arranged alternately and staggeredly (e.g., the upper flat part 501 corresponds to the lower inclined part 502, forming a stepped space). When the airflow containing sparks impacts the flat part 501, the large-mass sparks cannot follow the airflow due to inertia and directly hit the surface of the flat part 501. After losing horizontal kinetic energy, they begin to fall. The small sparks that are not intercepted by the flat part 501 enter the area of ​​the inclined part 502 with the airflow. The inclination angle of the inclined part 502 forces the airflow to flow along the inclined surface. The sparks hit the inclined part 502 due to inertia. Under the guidance of the inclined surface and the action of gravity, they slide into the spark settling chamber 52 of the adjacent interceptor plate 51 (instead of rebounding back into the airflow). The guide holes 53 on the inclined section 502 are aligned with the inclination angle. When the airflow flows along the inclined surface of the inclined section 502, it can quickly pass through the interceptor plate 51 through the guide holes 53, avoiding vortices and wind resistance caused by the "right-angle turn" and ensuring the air intake efficiency of the fan. At the same time, the inclined surface structure of the inclined section 502 expands the airflow contact area, further reducing the local wind speed and assisting in the settling of sparks. The alternating structure of the upper and lower interceptor plates 51 forms a trapezoidal spark settling cavity 52 with a "wider bottom and narrower top" between adjacent interceptor plates 51. The falling sparks accumulate in the cavity, preventing them from re-entering the airflow circulation, and are eventually cleaned up by a detachable ash collection box. Through the structural synergy of "hard blocking of the flat section 501 and soft guiding of the inclined section 502", the "inertial impact" of sparks is combined with "inclined surface guidance", which not only improves the spark interception efficiency, but also reduces wind resistance by guiding the airflow in a forward direction. This solves the technical contradiction of "mutual exclusion between interception and ventilation", allowing the fireproof centrifugal fan to both "block sparks" and "ventilate smoke" under fire conditions.

[0023] like Figure 2 As shown, in this embodiment, the optimized guide hole 53 is a circular hole or an oblong hole, and the guide holes 53 of the adjacent inclined portions 502 are staggered.

[0024] In this technical solution, the smooth contour of the circular / waist-shaped hole reduces airflow impact and avoids excessive wind resistance affecting the smoke exhaust efficiency of the fan; the guide holes 53 of the adjacent inclined part 502 are misaligned, forcing the sparks to hit the interceptor plate 51 due to inertia, reducing the risk of spark penetration.

[0025] Working principle: The edges of the circular or oblong holes are smooth and without sharp corners. When high-temperature flue gas (including sparks) flows through, the friction area between the airflow and the hole wall is smaller, and eddies are less likely to form, ensuring smooth airflow. The smooth hole shape also reduces the "cutting impact" on sparks, preventing them from getting stuck and causing local blockages. The strong airflow allows it to naturally diffuse and flow around the perimeter of the staggered holes, avoiding direct drafts (reducing the risk of sparks being re-engaged by the airflow) and making the airflow more evenly distributed within the interception component, further reducing local wind resistance.

[0026] like Figure 2 As shown, in this embodiment, the fireproof plate 9 is provided on the rear side of the interceptor plate 51. The fireproof plate 9 has a plurality of air inlet holes 10, and the air inlet holes 10 are connected to the guide holes 53. Fireproof expansion strips 11 are evenly spaced along the length direction on the rear side of the fireproof plate 9.

[0027] In this technical solution, the air inlet 10 of the fireproof board 9 and the guide hole 53 of the interceptor plate 51 are connected to ensure smooth airflow and at the same time intercept small sparks. When a fire occurs, the fireproof expansion strip 11 expands due to heat, sealing the gap between the boards and completely blocking the flow of sparks and high temperature penetration, thus strengthening fireproof isolation.

[0028] Working principle: A fireproof plate 9 is installed parallel to the rear side of the interceptor plate 51, with a small gap between them; fireproof expansion strips 11 are arranged at intervals along the length of the back side of the fireproof plate 9 (facing the casing 1) (the trigger temperature is usually 120-180℃). Large sparks are blocked by the interceptor plate 51; when small sparks enter the air inlet 10 of the fireproof plate 9 with the airflow, they settle due to friction of the hole wall and deceleration of the airflow (or are adsorbed by the surface of the fireproof plate 9), achieving dual purification of coarse filtration (interceptor plate 51) and fine filtration. The fireproof expansion strips 11 expand rapidly when heated (increasing in volume to 3-5 times), filling all gaps between the fireproof plate 9, the interceptor plate 51, and the casing 1, forming a continuous sealing barrier, completely sealing the gaps between the interceptor plate 51, the fireproof plate 9, and the casing 1, preventing sparks from entering the casing 1 by bypassing the flow, thus eliminating the risk of fire leakage; like Figure 2 As shown, in this embodiment, the air inlet 3 is optimized to have louvers 12 inside, and the louvers 12 are located behind the fireproof plate 9.

[0029] In this technical solution, the airflow filtered by the fireproof plate 9 is regulated to reduce eddies inside the casing 1 and lower ventilation resistance; a "secondary blocking" is performed on the trace sparks that are not intercepted by the fireproof plate 9 to improve fire protection reliability; when the pressure fluctuates in the fire scene, the reverse high-temperature airflow or flame backflow is blocked to protect the impeller 2 and transmission components 13 inside the casing 1.

[0030] Working principle: Louvers 12 are installed inside the air inlet 3, behind the fireproof plate 9 (close to the inner side of the casing 1). The blades are made of high-temperature resistant materials (such as aluminum alloy and stainless steel) and have adjustable angle and unidirectional conduction characteristics (maintaining a preset opening angle under normal conditions and automatically closing when the airflow is reversed). The airflow filtered through the air inlet 10 of the fireproof plate 9 (removing most sparks) enters the louver 12 area and is guided by the louver 12 blades at a preset angle (such as 15°-30° with the airflow direction) to enter the casing 1 along a smooth path. This avoids the airflow directly impacting the casing 1 wall or impeller 2 to generate vortices. Compared with a structure without louvers 12, it can reduce wind resistance loss by about 10%-20% and ensure the fan's smoke exhaust efficiency. If a small amount of tiny sparks (such as spark particles with a diameter of <1mm) remain in the airflow, due to the greater inertia of the sparks than the airflow, they will impact the surface of the louver 12 blades (the gap between the blades is only 5-8mm and they are arranged at an angle). After losing kinetic energy, they will sink to the bottom of the casing 1 with the airflow (or be blocked by the blades) and will not be able to contact the transmission component 13, forming a triple spark blocking effect of the fireproof interception component 5, the fireproof plate 9, and the louver 12. When a local high pressure occurs in the fire scene (such as deflagration, pressure difference caused by local fire extinguishing), causing the airflow to flow in reverse (from the casing 1 back to the air inlet 3): the reverse airflow will push the louver 12 blades to rotate around the axis to a closed state, and the edges of the blades will stick together to form a "temporary sealing barrier", blocking the high-temperature airflow, flames, or residual sparks flowing in reverse, preventing them from flowing back to the outside through the air inlet 3 (or impacting the fireproof plate 9 and the interception component, damaging the previous protective structure); at the same time, the closed louver 12 can reduce the heat loss from the casing 1 to the outside, and together with the heat insulation protective cover 6, further maintain a relatively low temperature environment around the transmission component 13.

[0031] Example 2: This embodiment provides a fireproof centrifugal fan, which, in addition to the technical solutions of the above embodiments, also has the following technical features.

[0032] like Figures 1-3 As shown, in this embodiment, the optimized transmission assembly 13 includes: An explosion-proof motor 131 is installed inside the heat insulation chamber 7; The drive shaft 132 is rotatably installed inside the housing 1, and one end of the drive shaft 132 extends through the interior of the heat insulation protective cover 6. Small pulley 133 is mounted on the output shaft of explosion-proof motor 131; A large pulley 134 is mounted on the drive shaft 132; A flat belt 135 is fitted between the small pulley 133 and the large pulley 134.

[0033] In this technical solution, the explosion-proof motor 131 is used to block the leakage of internal electrical sparks, preventing the ignition of external sparks or high-temperature flue gas; combined with the heat insulation material of the heat insulation cavity 7 and the heat dissipation structure of the protective cover, the motor and belt are ensured not to fail in high-temperature environments; through the flexible transmission of the pulley and the flat belt 135, vibration is buffered and the installation space of the motor and the transmission shaft 132 is adapted to ensure that the impeller 2 rotates continuously and stably without interrupting the smoke exhaust function.

[0034] Working principle: The explosion-proof motor 131 is placed in the heat insulation cavity 7 as the power source. Through the transmission chain of "small pulley 133 → flat belt 135 → large pulley 134", the power is transmitted to the transmission shaft 132 in the housing 1, which finally drives the impeller 2 to rotate. The entire transmission system is wrapped by the heat insulation cover 6 and the heat insulation cavity 7, forming an integrated structure of power output and heat protection. After the explosion-proof motor 131 is powered on, its output shaft drives the small pulley 133, which is fixed on the same axis, to rotate. The small pulley 133 transmits the torque to the large pulley 134 on the drive shaft 132 through the flat belt 135 (the belt drive has flexible buffering characteristics, which can absorb the vibration of the motor and the drive shaft 132 and avoid the wear of parts caused by rigid transmission). The large pulley 134 rotates synchronously with the drive shaft 132, which in turn drives the impeller 2 in the housing 1 to rotate, generating negative pressure to draw in the smoke in the fire scene and realize the smoke exhaust function (the "small pulley leading large pulley" design can adjust the transmission ratio according to the speed requirements of the impeller 2 to adapt to different smoke exhaust scenarios). The explosion-proof motor 131 has its own explosion-proof housing. Even if electrical sparks occur inside the motor due to high temperature (such as sparks caused by aging winding insulation), the housing can block the sparks from leaking out, preventing the sparks from contacting external sparks or high-temperature smoke, and preventing the risk of "internal ignition of external parts". The explosion-proof motor 131 is located in a closed heat-insulating cavity 7. The heat-insulating material (such as ceramic fiber cotton) filled in the cavity can block the transmission of high temperature in the fire to the motor. At the same time, the heat dissipation fins 8 on the outer surface of the heat-insulating protective cover 6 can dissipate the heat generated by the motor itself (and a small amount of external heat that penetrates) through air convection, ensuring that the motor temperature does not exceed the tolerance threshold (preventing winding burnout and belt softening). The flat belt 135 is made of high-temperature resistant rubber or fiber material (suitable for medium and high temperatures in fire scenarios). With the smooth surface of the pulley, it can reduce friction loss at high temperatures, prevent the belt from breaking or slipping due to overheating, and ensure uninterrupted power transmission.

[0035] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A fireproof centrifugal fan, comprising a casing (1), an impeller (2) rotatably disposed within the casing (1), a transmission assembly (13) drivingly connected to the impeller (2), and an air inlet (3) and an air outlet (4) provided in the casing (1), characterized in that: Fireproof interception component (5), the air inlet (3) is detachably installed with fireproof interception component (5), the fireproof interception component (5) includes multiple layers of interception plates (51) arranged in a stepped staggered manner, a spark settling cavity (52) is formed between adjacent interception plates (51), and several guide holes (53) are opened on each interception plate (51). The transmission assembly (13) is provided with a heat insulation shield (6) on the outside. A closed heat insulation cavity (7) is formed between the heat insulation shield (6) and the transmission assembly (13). The heat insulation cavity (7) is filled with heat insulation material, and heat dissipation fins (8) are integrally formed on the outer surface of the heat insulation shield (6).

2. The fire-safe centrifugal fan of claim 1, wherein The interceptor plate (51) is composed of a flat part (501) and an inclined part (502) that is inclinedly connected to the flat part (501). The flat part (501) and the inclined part (502) are alternately arranged in the up and down direction, and the guide hole (53) is arranged on the inclined part (502).

3. The fire-safe centrifugal fan of claim 2, wherein, The guide hole (53) is a circular hole or a waist-shaped hole, and the guide holes (53) of the inclined portions (502) of the two adjacent layers are staggered.

4. The fire-safe centrifugal fan of claim 1, wherein The interceptor plate (51) is provided with a fireproof plate (9) on the rear side. The fireproof plate (9) has several air inlets (10) and the air inlets (10) are connected to the guide holes (53). Fireproof expansion strips (11) are provided evenly at intervals along the length direction on the rear side of the fireproof plate (9).

5. The fire-safe centrifugal fan of claim 4, wherein, The air inlet (3) is provided with louvers (12), and the louvers (12) are located behind the fireproof board (9).

6. The fire-safe centrifugal fan of claim 1, wherein The transmission assembly (13) includes: An explosion-proof motor (131) is installed inside the heat insulation cavity (7); The drive shaft (132) is rotatably disposed inside the housing (1), and one end of the drive shaft (132) extends through the interior of the heat insulation shield (6); A small pulley (133) is mounted on the output shaft of the explosion-proof motor (131); A large pulley (134) is mounted on the drive shaft (132); A flat belt (135) is fitted between the small pulley (133) and the large pulley (134).

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