A backdraft prevention mechanism of a centrifugal fan

Abstract

The utility model discloses a kind of anti-back air mechanism of centrifugal fan, it is related to textile workshop cleaning equipment technical field, the mechanism includes fan shell, rotating motor, air inlet and impeller, at least two air outlets are equipped on fan shell, each air outlet is equipped with self-adapting check door component. The check door component is realized automatic opening and closing by the dynamic balance of airflow dynamic pressure and the moment effect of gravity or counterweight device: when fan operates, the airflow pressure generated by impeller pushes check door to open air outlet;When stopping, check door is automatically closed under the action of gravity or counterweight, and air flow is blocked in reverse flow. Up and down air outlet layout optimizes airflow distribution, synchronous opening and closing design enhances sealing reliability, without additional driving device, structure is simple and cost is low. The utility model significantly improves the suction efficiency of fiber inside cleaning box, with high reliability and practicality.

Description

Technical Field

[0001] This utility model relates to the field of cleaning equipment technology for textile workshops, and in particular to a backflow prevention mechanism for centrifugal fans. Background Technology

[0002] Centrifugal fans, as the core power source for cleaning equipment in textile workshops, are widely used due to their efficient and stable air delivery performance. In fiber extraction operations, the centrifugal fan connects to the cleaning chamber through its inlet, utilizing negative pressure to adsorb fibers or dust accumulated inside the chamber. However, traditional centrifugal fans have significant drawbacks in practical applications:

[0003] 1. Reduced suction power due to backflow during shutdown: When the cleaning chamber is full of fibers that need to be sucked out, the centrifugal fan needs to be stopped. At this time, since the air outlet is open, the external airflow can easily flow back into the fan casing through the air outlet, weakening the negative pressure suction inside the cleaning chamber, resulting in a significant reduction in fiber suction efficiency and a longer operation time.

[0004] 2. Reliance on complex drive devices: Some improvement solutions attempt to control the opening and closing of the air outlet through external drive devices such as solenoid valves and electric actuators. However, such designs require additional control circuits, sensors and power components, which not only increases manufacturing costs but also increases the failure rate due to the complexity of the mechanical structure. They are difficult to adapt to the harsh environment of high dust and high humidity in textile workshops.

[0005] 3. Delayed opening and closing response: Existing manual or semi-automatic valves require manual intervention or signal triggering, which cannot adapt to the fan's operating status in real time. This results in a delay between the opening and closing action and the fan's start and stop, further exacerbating the suction fluctuation problem.

[0006] The aforementioned problems severely restrict the operational efficiency and reliability of cleaning equipment. Therefore, there is an urgent need for a simple, externally driven anti-backflow mechanism that can adapt to the fan's start and stop states to solve the problem of insufficient suction caused by untimely closure of the air outlet, while simultaneously reducing maintenance costs and energy consumption. Utility Model Content

[0007] In order to overcome the above-mentioned defects of the prior art, the present invention provides a backflow prevention mechanism for a centrifugal fan.

[0008] To achieve the above objectives, this utility model provides a backflow prevention mechanism for a centrifugal fan, including a fan housing, a rotary motor located on the back of the fan housing, an air inlet located on the front of the fan housing, and an impeller located inside the air inlet. The output end of the rotary motor is connected to the impeller. Its innovation lies in that: the fan housing is provided with at least two air outlets, and each air outlet is provided with an adaptive check valve assembly.

[0009] The adaptive check door assembly includes a hinged check door configured as follows:

[0010] When the rotating motor drives the impeller to rotate, the air pressure generated by the impeller pushes the check valve to open the corresponding air outlet;

[0011] When the rotating motor stops running, the check valve automatically closes the corresponding air outlet under the action of gravity or the torque of the counterweight device to prevent the airflow from flowing back.

[0012] Furthermore, at least two air outlets include an upper air outlet located on the upper part of the fan housing and a lower air outlet located on the lower part of the fan housing, and the adaptive check valve assembly includes an upper check valve located on the upper air outlet and a lower check valve located on the lower air outlet.

[0013] Furthermore, symmetrical upper clamping plates are provided on both sides of the aforementioned upper air outlet, and two upper check doors that can move synchronously are connected between the two upper clamping plates by hinges.

[0014] The upper check valve hinges upward under the action of airflow pressure to open the upper air outlet, and hinges downward under the action of gravity to close the upper air outlet.

[0015] Furthermore, symmetrical lower clamping plates are provided on both sides of the aforementioned lower air outlet, and two lower check doors that can move synchronously are connected between the two lower clamping plates by hinges.

[0016] The lower check valve moves downward under the action of air pressure to open the lower air outlet, and automatically moves upward under the gravity torque of the counterweight device to close the lower air outlet.

[0017] Furthermore, a rotating rod is provided at the connection between the lower check valve and the lower clamping plate, and the counterweight device is a hammer. The rotating rod extends to the outside of the lower clamping plate, and the hammer is located at the end of the rotating rod.

[0018] The weight of the counterweight is matched with the length of the rotating rod, ensuring that the torque generated when the machine stops is greater than the sum of the weight of the lower check valve and the residual pressure of the airflow, thus guaranteeing reliable closure.

[0019] When the lower air outlet is closed by the check valve, the counterweight is perpendicular to the horizontal plane.

[0020] When the lower air outlet is opened by the check valve, the counterweight is parallel to the horizontal plane.

[0021] Furthermore, the opening and closing action of the aforementioned adaptive check valve assembly relies on the balance between airflow pressure and gravity or counterweight torque, requiring no additional drive device.

[0022] The beneficial effects of this utility model are:

[0023] 1. Improved backflow prevention performance: The air outlet automatically closes when the machine stops to prevent airflow from flowing back, ensuring concentrated suction inside the cleaning chamber and significantly improving fiber extraction efficiency.

[0024] 2. Simple and reliable structure: No additional driving devices such as solenoid valves and sensors are required. It relies on the balance between air flow pressure and the torque of gravity / counterweight device, which reduces manufacturing costs and failure rate. Attached Figure Description

[0025] Figure 1 This is an isometric view of the front of this utility model.

[0026] Figure 2 This is a structural diagram of the bottom of this utility model.

[0027] The reference numerals in the attached figures are as follows:

[0028] Fan casing (1), rotary motor (11), air inlet (12), impeller (13), upper air outlet (14), upper check valve (15), lower air outlet (16), lower check valve (17), upper clamping plate (2), lower clamping plate (3), rotating rod (31), and counterweight (32). Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] like Figures 1 to 2 In one specific embodiment of this utility model, the structure includes a fan housing 1, a rotary motor 11, an air inlet 12, and an impeller 13. The fan housing 1 is provided with at least two air outlets, and each air outlet is provided with an adaptive check valve assembly. The adaptive check valve assembly includes a hinged check valve, the opening and closing of which is controlled by the airflow pressure and the torque of the gravity / counterweight device.

[0031] Opening: When impeller 13 is running, the airflow pressure pushes the check valve to open the air outlet;

[0032] Closed: When impeller 13 stops, the check valve automatically closes under the action of gravity or the torque of the counterweight device to prevent backflow.

[0033] Core technology: The air outlet achieves adaptive opening and closing through the dynamic balance of air pressure and the torque of gravity / counterweight device, without the need for an external drive device.

[0034] Key components:

[0035] Air outlets: The design of at least two air outlets ensures balanced airflow distribution and avoids excessive local pressure caused by a single outlet.

[0036] Adaptive check valve: The hinged structure allows the check valve to respond flexibly to changes in airflow, and the torque of gravity or counterweight ensures rapid closure when the machine stops.

[0037] Technical effect: It solves the problem of insufficient suction in the cleaning chamber caused by the open air outlet of traditional centrifugal fans, and improves the cleaning efficiency of the fibers inside the cleaning chamber.

[0038] In this utility model, as a preferred embodiment, at least two air outlets include an upper air outlet 14 and a lower air outlet 16, which correspond to an upper check valve 15 and a lower check valve 17, respectively.

[0039] Layout optimization: The upper and lower dual air outlet design disperses the airflow pressure inside the fan casing, avoiding local airflow congestion or excessive pressure caused by a single air outlet, thereby improving the fan's operating efficiency.

[0040] Adaptability: The top and bottom layout can be adapted to different installation scenarios (such as the top or bottom of cleaning equipment), improving the versatility of the mechanism.

[0041] Anti-return air coordination: The simultaneous opening and closing of the two outlets reduces the risk of leakage caused by the incomplete closure of a single outlet.

[0042] In this utility model, as a preferred embodiment, upper clamping plates 2 are symmetrically arranged on both sides of the upper air outlet 14, and two upper check valves 15 that can move synchronously are hinged between the two upper clamping plates 2; the airflow pushes the upper check valves 15 to open upwards, and closes downwards under the action of gravity.

[0043] Structural details:

[0044] Upper clamping plate 2: The symmetrical design ensures the stability of the check valve's movement trajectory and avoids jamming caused by uneven load.

[0045] Synchronous movement: The two check valves are linked by hinges to ensure that the air outlets open evenly and avoid uneven force on one side.

[0046] Action Mechanism:

[0047] Opening: The airflow pressure overcomes the gravity of the check valve, pushing it to flip upwards;

[0048] Closure: After the airflow disappears, the check valve will naturally droop and close under its own gravity, without the need for external intervention.

[0049] In this utility model, as a preferred embodiment, lower clamping plates 3 are symmetrically arranged on both sides of the lower air outlet 16, and two lower check valves 17 that can move synchronously are hinged between the two lower clamping plates 3; the airflow pushes the lower check valves 17 to open downwards, and gravity or counterweight device causes them to close upwards.

[0050] Structural features:

[0051] Lower clamp 3: Similar to the upper clamp, but adapted to the reverse movement requirements of the lower air outlet.

[0052] Counterweight device: For downward-opening check valves, an additional counterweight (the hammer as described in claim 5) is required to assist in closing.

[0053] Mechanical design of counterweight device:

[0054] The weight of the hammer ( ) and the length of the rotating rod ( )satisfy ,in, Let d be the weight of the door itself, and d be the distance from the door's center of gravity to the hinge. The hinge friction torque ensures reliable closure when the machine stops.

[0055] Action Mechanism:

[0056] Opening: Airflow pressure pushes the check valve downwards, in the opposite direction of gravity;

[0057] When shut down, the counterweight (weight 32) or the torque of the counterweight of the check valve itself causes it to return to its original position.

[0058] In this utility model, as a preferred embodiment, a rotating rod 31 is provided at the connection between the lower check valve 17 and the lower clamping plate 3, and a counterweight 32 is provided at the end of the rotating rod 31; when closed, the counterweight is vertical, and when opened, it is parallel to the horizontal plane.

[0059] Counterweight design:

[0060] Rotating rod 31: Extends the torque arm, amplifies the gravitational effect of the weight 32, and ensures sufficient closing force.

[0061] Heavy Hammer 32:

[0062] Closed state: The vertical weight provides maximum torque, enhancing the tightness of the closure;

[0063] When open: Reduces movement resistance in the parallel direction to avoid affecting airflow efficiency.

[0064] Dynamic balancing: The position of the counterweight is automatically adjusted according to the movement of the check valve, achieving a balance between efficient opening and closing and stable closing.

[0065] In this invention, as a preferred embodiment, the opening and closing of the adaptive check valve assembly relies on the balance between the air pressure and the torque of the gravity / counterweight device, without the need for an additional drive device.

[0066] Technical advantages:

[0067] Simplified structure: Eliminates drive components such as solenoid valves and motors, reducing manufacturing costs and failure rates.

[0068] Energy efficiency: It requires no external power or control signals, operates based on physical principles, and is energy-saving and environmentally friendly.

[0069] Reliability: No complex electronic components, suitable for industrial environments with high dust and high humidity.

[0070] Core principle: Utilizing the airflow characteristics of the centrifugal fan itself and the gravity response of the mechanical structure to form a closed-loop control.

[0071] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0072] Secondly: The accompanying drawings of the embodiments disclosed in this utility model only involve the structures involved in the embodiments disclosed in this utility model. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this utility model can be combined with each other.

[0073] Finally: The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A backflow prevention mechanism for a centrifugal fan, comprising a fan housing, a rotary motor disposed on the back of the fan housing, an air inlet disposed on the front of the fan housing, and an impeller disposed inside the air inlet, wherein the output end of the rotary motor is connected to the impeller, characterized in that: The fan casing is provided with at least two air outlets, and each air outlet is provided with an adaptive check valve assembly; The adaptive check door assembly includes a hinged check door, configured as follows: When the rotary motor drives the impeller to rotate, the air pressure generated by the impeller pushes the check valve to open the corresponding air outlet; When the rotary motor stops operating, the check valve automatically closes the corresponding air outlet under the action of gravity or the torque of the counterweight device to prevent the airflow from flowing back.

2. The anti-backflow mechanism for a centrifugal fan according to claim 1, characterized in that, At least two air outlets include an upper air outlet located on the upper part of the fan housing and a lower air outlet located on the lower part of the fan housing. The adaptive check valve assembly includes an upper check valve located on the upper air outlet and a lower check valve located on the lower air outlet.

3. The anti-backflow mechanism for a centrifugal fan according to claim 2, characterized in that, The upper air outlet is symmetrically provided with upper clamping plates on both sides, and the two upper clamping plates are connected by hinges to two upper check doors that can move synchronously. The upper check valve hinges upward under the action of air pressure to open the upper air outlet, and hinges downward under the action of gravity to close the upper air outlet.

4. The anti-backflow mechanism for a centrifugal fan according to claim 2, characterized in that, The lower air outlet is symmetrically provided with lower clamping plates on both sides, and the two lower clamping plates are connected by a hinge to two lower check doors that can move synchronously. The lower check valve hinges downward under the action of air pressure to open the lower air outlet, and automatically hinges upward under the gravity torque of the counterweight device to close the lower air outlet.

5. The anti-backflow mechanism for a centrifugal fan according to claim 4, characterized in that, A rotating rod is provided at the connection between the lower check valve and the lower clamping plate. The counterweight device is a hammer. The rotating rod extends to the outside of the lower clamping plate, and the hammer is located at the end of the rotating rod. The weight of the counterweight is matched to the length of the rotating rod, ensuring that the torque generated when the machine stops is greater than the sum of the weight of the lower check valve and the residual pressure of the airflow, thus guaranteeing reliable closure. When the lower check valve closes the lower air outlet, the counterweight is perpendicular to the horizontal plane; When the lower check valve opens the lower air outlet, the counterweight is parallel to the horizontal plane.

6. The anti-backflow mechanism for a centrifugal fan according to any one of claims 1-5, characterized in that, The opening and closing action of the adaptive check valve assembly depends on the balance between air pressure and gravity or counterweight torque, and no additional drive device is required.

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