Pressure relief valve for explosion-proof fan

Abstract

The utility model provides a pressure relief valve for an explosion-proof fan, and belongs to the technical field of fan pressure relief valves. The pressure relief valve for the explosion-proof fan comprises a pressure relief valve body and a filter cover, the pressure relief valve body comprises a first valve pipe and a second valve pipe which are fixedly connected with each other, a valve pipe air inlet and a valve pipe air outlet are formed in the two opposite ends of the first valve pipe and the second valve pipe respectively, a center valve rod of the pressure relief valve body is sleeved with a spring seat, a reset spring and a piston switch, and a plurality of ventilation openings are formed in the conical side wall of the spring seat. The bottom of the piston switch is blocked by a valve pipe check ring formed at the valve pipe connecting position, and the piston switch and the valve pipe are relatively elastically connected through a reset spring. The filter cover comprises a thin-shell hemispherical structural frame at the upper end and a connecting part at the lower end, a filter screen is arranged between the structural frames, and the filter cover can be mounted on the valve pipe air inlet or the valve pipe air outlet through threaded connection. The explosion-proof fan has the advantages of automatically releasing pressure, avoiding pipeline blockage, improving the operation safety of the explosion-proof fan, being simple in structure and easy to disassemble and assemble, and improving the airflow flowing efficiency.

Description

Technical Field

[0001] The utility model belongs to the technical field of fan pressure relief valves, and in particular relates to a pressure relief valve for explosion-proof fans. Background Art

[0002] A vortex blower is a high-pressure blower that outputs air pressure through pipes connected to its inlet and outlet ports. Therefore, if the inlet or pipe is blocked, the internal air pressure of the blower will rise rapidly, causing the blower to generate excessive heat and the motor to overcurrent and cause damage. Patent application number CN202122462301.4 discloses a new blower pressure relief valve structure. By installing a pressure relief valve and a pressure gauge at 1 / 3 of the distance from the air inlet, the blower can be monitored for pipe blockage and protect the blower.

[0003] However, for explosion-proof vortex fans, since they are used in flammable and explosive environments for a long time, a large amount of combustible gases, high-density dust, etc. in the outside world will invade the inside of the fan through the pressure relief valve, causing further pipeline blockage problems. Utility Model Content

[0004] The purpose of the utility model is to provide a pressure relief valve for explosion-proof blowers in order to solve the above problems in the prior art.

[0005] The purpose of the utility model can be achieved through the following technical solutions: A pressure relief valve for an explosion-proof fan, comprising a pressure relief valve body and a filter cover, wherein the pressure relief valve body is installed on the air inlet and outlet ducts of the explosion-proof fan, and comprises a first valve pipe and a second valve pipe;

[0006] The outer diameter of the first valve pipe gradually increases to present a tapered structure, and the inner diameter of the pipe is uniformly set. The first valve pipe is formed with a valve pipe air inlet at the end with a smaller outer diameter. One end of the second valve pipe extends into the interior of the end with a larger outer diameter of the first valve pipe and is fixedly connected thereto, and the other end is formed with a valve pipe air outlet.

[0007] The pressure relief valve body is provided with a central valve stem at the inner central axis thereof, which passes through the first valve tube and the second valve tube. The central valve stem is sequentially sleeved with a spring seat, a return spring and a piston switch. The spring seat protrudes toward the piston switch to form a thin shell cone structure, and a plurality of vents are opened circumferentially on the conical sidewall thereof. A valve tube retaining ring is formed circumferentially on the inner sidewall of the first valve tube at the top of the connection between the first and second valve tubes. The bottom of the piston switch is blocked by the valve tube retaining ring. The two ends of the return spring are respectively sleeved on the spring seat and the piston switch to elastically connect the two relative to each other.

[0008] The filter cover includes a thin hemispherical structural frame at the upper end and a connecting part at the lower end, wherein filter screens are arranged between the structural frames. The outer walls of the valve pipe air inlet and the valve pipe air outlet are both provided with threads, and the inner wall of the connecting part is also provided with threads. Therefore, the filter cover can be installed on the valve pipe air inlet or valve pipe air outlet through threaded connection according to actual needs.

[0009] In the above-mentioned pressure relief valve for explosion-proof fans, the first valve pipe and the second valve pipe are fixedly connected via a threaded connection.

[0010] In the above-mentioned pressure relief valve for explosion-proof fans, spiral air ports are formed at both ends of the central valve stem at the valve pipe air inlet and the valve pipe air outlet. The spiral air ports are composed of several spiral blades uniformly arranged circumferentially around the ports at both ends of the central valve stem.

[0011] In the above-mentioned pressure relief valve for explosion-proof blowers, a gasket is provided between the spring seat and the bottom of the valve pipe air inlet.

[0012] In the above-mentioned pressure relief valve for explosion-proof blowers, the filter cover is formed with an anti-slip structure on the outer side wall of the connecting portion.

[0013] Compared with the existing technology, the explosion-proof blower pressure relief valve provided by the utility model has the following advantages:

[0014] 1. When the inlet and outlet ducts of the explosion-proof fan are blocked, the pressure can be automatically adjusted and released under the action of the internal and external pressure difference, protecting the explosion-proof fan from operating risks caused by overload and overheating, thereby improving safety;

[0015] Second, by installing a filter cover at the air outlet of the pressure relief valve, it can effectively prevent external dust from invading the fan pipe and causing pipe blockage when it is in a flammable and explosive environment, thereby extending the service life of the explosion-proof fan;

[0016] 3. The structure is simple and effective, easy to install, disassemble and maintain;

[0017] 4. By setting the spiral air outlet, the air flow interference can be effectively reduced when the pressure relief valve is in and out, and the pressure loss can be reduced, so that the air flow has a higher flow efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the installation diagram of the pressure relief valve for this explosion-proof fan;

[0019] Figure 2 This is a cross-sectional view of the structure of the pressure relief valve for explosion-proof fans;

[0020] Figure 3 This is a structural diagram of the filter cover in the pressure relief valve for explosion-proof fans;

[0021] In the above figure, 100, pressure relief valve body; 110, first valve tube; 111, valve tube air inlet; 112, valve tube retaining ring; 120, second valve tube; 121, valve tube air outlet; 130, center valve stem; 131, spiral air outlet; 140, spring seat; 141, vent; 142, gasket; 150, return spring; 160, piston switch; 200, filter cover; 210, structural frame; 220, filter screen; 230, connecting part; 231, anti-slip structure. DETAILED DESCRIPTION

[0022] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0023] like Figures 1 to 3 As shown, the pressure relief valve for explosion-proof fans includes a pressure relief valve body 100 and a filter cover 200. The pressure relief valve body 100 is installed on the inlet and outlet air ducts of the explosion-proof fan. If necessary, a pressure gauge for detecting the internal pressure of the ducts can be installed next to the pressure relief valve body 100 to facilitate real-time observation of changes in the internal air pressure of the explosion-proof fan. The pressure relief valve body 100 includes a first valve pipe 110 and a second valve pipe 120, which are fixedly connected to each other. The filter cover 200 is installed at the air outlet of the first valve pipe 110 or the air outlet of the second valve pipe 120.

[0024] like Figure 2 As shown, the inner diameter of the first valve tube 110 is uniform, and the outer diameter gradually increases toward the direction of the second valve tube 120, presenting a tapered structure. This facilitates indicating the direction of air inlet and outlet when the pressure relief valve is in use. The first valve tube 110 has a valve tube air inlet 111 formed at the end with a smaller outer diameter. One end of the second valve tube 120 extends into the interior of the end with a larger outer diameter of the first valve tube 110. This end has threads on its outer wall. The inner wall of the end of the first valve tube 110 connected to this end also has mating threads, ensuring that the first valve tube 110 and the second valve tube 120 are fixedly connected via a threaded connection. The other end of the second valve tube 120 has a valve tube air outlet 121 formed.

[0025] To further illustrate, the inner diameter of the valve tube air inlet 111 is slightly smaller than the inner diameter of the first valve tube 110 as a whole, and an offset step is formed at the bottom of the valve tube air inlet 111; the inner diameter of the valve tube air outlet 121 is slightly smaller than the inner diameter of the other end of the second valve tube 120; a circle of valve tube retaining ring 112 is formed circumferentially on the inner wall of the first valve tube 110 at the top of the connection between the first valve tube 110 and the second valve tube 120, and the inner diameter of the valve tube retaining ring 112 is smaller than the inner diameter of the second valve tube 120, forming a blocking surface.

[0026] The pressure relief valve body 100 has a central valve stem 130 positioned at its inner center axis, traversing the first and second valve tubes 110 and 120. Spiral air ports 131 are formed at each end of the central valve stem 130, at the valve tube air inlet 111 and valve tube air outlet 121. These spiral air ports 131 consist of several spiral blades evenly spaced around the ends of the central valve stem 130 and are integrated with the valve tubes. The spiral air ports 131 effectively reduce airflow interference and pressure loss during air inlet and outlet, thereby enhancing airflow efficiency. A spring seat 140, a return spring 150, and a piston switch 160 are sequentially mounted on the central valve stem 130.

[0027] Spring seat 140 is mounted on a step at the bottom of valve tube air inlet 111. A gasket 142 is placed between the outer edge of its base and the bottom of valve tube air inlet 111 for cushioning and securing the connection. The center of spring seat 140 protrudes toward piston switch 160, forming a thin, conical shell. Its bottom fits snugly over central valve stem 130, creating a funnel-shaped airflow-guiding space. Several vents 141 are circumferentially defined along the tapered sidewalls of spring seat 140. While ensuring the overall structural strength of spring seat 140, the size and number of vents 141 should maximize airflow.

[0028] The upper middle portion of piston switch 160 has a stepped frustoconical structure. The base at the bottom extends outward until its outer diameter is larger than the inner diameter of valve tube retaining ring 112, allowing the base to be positioned within second valve tube 120 and blocked by valve tube retaining ring 112. The two ends of return spring 150 are tightly fitted around the outer sides of the thin cone structure of spring seat 140 and the stepped frustoconical structure of piston switch 160, respectively, elastically connecting the spring seat 140 and piston switch 160.

[0029] When the explosion-proof fan is not in use or is operating normally, the bottom of the piston switch 160 is tightly attached to the valve tube retaining ring 112 under the elastic force of the return spring 150, separating the interior of the first valve tube 110 from the interior space of the second valve tube 120 to prevent air pressure leakage inside the explosion-proof fan; when the explosion-proof fan is blocked or the air pressure inside the machine is too high, an air pressure difference is formed inside the first valve tube 110 and the second valve tube 120 of the pressure relief valve body 100, and the air flow enters from the valve tube air inlet 111, passes through the vent 141 of the spring seat 140, and impacts the piston switch 160, causing the piston switch 160 to displace along the center valve stem 130, and its base is separated from the valve tube retaining ring 112. The air flow flows out from the valve tube air outlet 121 through the valve tube retaining ring 112, releasing the pressure inside the explosion-proof fan, protecting the explosion-proof fan from operating risks due to overload and overheating, and improving the safety of the explosion-proof fan.

[0030] like Figure 3As shown, the filter cover 200 includes a structural frame 210 at the upper end and a connecting portion 230 at the lower end. The structural frame 210 is generally a thin shell hemispherical structure, with a plurality of structural ribs formed circumferentially from the top. Filter screens 220 are disposed between adjacent structural ribs. Filter screens 220 filter dust, providing pressure relief protection when the explosion-proof blower is in a flammable and explosive environment, while also effectively preventing external dust from invading the blower duct and causing duct blockage, thereby extending its service life.

[0031] External threads are formed on the outer walls of the valve pipe air inlet 111 and valve pipe air outlet 121 on the pressure relief valve body 100. Corresponding internal threads are also formed on the inner wall of the connection portion 230 of the filter cover 200. This allows the filter cover 200 to be threadedly installed on the valve pipe air inlet 111 or valve pipe air outlet 121 as needed. Anti-slip structures 231 are uniformly formed circumferentially on the outer wall of the connection portion 230 of the filter cover 200 to facilitate twisting when installing and removing the filter cover 200.

[0032] To further illustrate, when the pressure relief valve body 100 is installed on the air inlet duct of the explosion-proof fan, the valve tube air outlet 121 of the second valve tube 120 is connected to the air inlet duct, and the filter cover 200 is installed on the valve tube air inlet 111 of the first valve tube 110; when the pressure relief valve body 100 is installed on the air outlet duct of the explosion-proof fan, the valve tube air inlet 111 of the first valve tube 110 is connected to the air outlet duct, and the filter cover 200 is installed on the valve tube air outlet 121 of the second valve tube 120.

[0033] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

[0034] Although various terms are used in this document, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. A pressure relief valve for an explosion-proof blower, comprising a pressure relief valve body (100) and a filter cover (200); the pressure relief valve body (100) is installed on an air inlet and outlet duct of the explosion-proof blower, and comprises a first valve pipe (110) and a second valve pipe (120); It is characterized by: The outer diameter of the first valve tube (110) gradually increases, presenting a tapered structure, and the inner diameter of the tube is uniformly set. The first valve tube (110) is formed with a valve tube air inlet (111) at the end with a smaller outer diameter. One end of the second valve tube (120) extends into the interior of the end with a larger outer diameter of the first valve tube (110) and is fixedly connected thereto, and the other end is formed with a valve tube air outlet (121); The pressure relief valve body (100) is provided with a central valve stem (130) which crosses the first valve tube (110) and the second valve tube (120) at the inner central axis. The central valve stem (130) is sequentially sleeved with a spring seat (140), a return spring (150) and a piston switch (160). The spring seat (140) protrudes toward the piston switch (160) to form a thin shell cone structure. A plurality of vents (141) are opened on the conical side wall. A circle of valve tube retaining ring (112) is formed on the inner side wall of the first valve tube (110) at the top of the connection between the first valve tube (110) and the second valve tube (120). The bottom of the piston switch (160) is blocked by the valve tube retaining ring (112). The two ends of the return spring (150) are respectively sleeved on the spring seat (140) and the piston switch (160) to elastically connect the two relative to each other. The filter cover (200) comprises a thin hemispherical structural frame (210) at the upper end and a connecting portion (230) at the lower end, wherein a filter screen (220) is provided between the structural frames (210), and threads are provided on the outer side walls of the valve pipe air inlet (111) and the valve pipe air outlet (121), and threads are also provided on the inner side wall of the connecting portion (230), thereby the filter cover (200) can be installed on the valve pipe air inlet (111) or the valve pipe air outlet (121) through threaded connection according to actual needs.

2. A pressure relief valve for explosion-proof blowers according to claim 1, characterized in that: The first valve tube (110) and the second valve tube (120) are fixedly connected via a threaded connection.

3. The pressure relief valve for explosion-proof blower according to claim 1, characterized in that: Spiral air ports (131) are formed at both ends of the central valve stem (130) at the valve pipe air inlet (111) and the valve pipe air outlet (121). The spiral air ports (131) are formed by a plurality of spiral blades uniformly arranged around the ports at both ends of the central valve stem (130).

4. A pressure relief valve for explosion-proof blowers according to claim 1, characterized in that: A gasket (142) is provided between the spring seat (140) and the bottom of the valve tube air inlet (111).

5. The pressure relief valve for explosion-proof blower according to claim 1, characterized in that: The filter cover (200) is formed with an anti-slip structure (231) on the outer side wall of the connecting portion (230).

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