Threaded explosion-proof air inlet device of explosion-proof draw-out type ventilator

Abstract

The invention belongs to the technical field of underground coal mine ventilation safety, and particularly relates to a threaded explosion-proof air inlet device of an explosion-proof draw-out type ventilator, which comprises an air inlet pipeline, an air inlet screw, an air outlet pipeline and an air outlet pipeline, an external thread is arranged at the lower part of the outer end of the air inlet screw and is matched with an internal thread of a motor shell to form a thread explosion-proof surface; the upper end of the air inlet screw is an internal thread blind hole to be connected with an air inlet pipeline, and the lower end of the internal thread blind hole is provided with a plurality of air inlet side holes communicated with the thread explosion-proof surface; gas sequentially passes through the gas inlet pipeline, the internal thread blind hole of the gas inlet screw, the gas inlet side hole and the thread fit clearance to enter the motor shell. According to the invention, the threaded explosion-proof surface is combined with the air inlet passage, the threaded explosion-proof surface conforming to the GB3836 standard is formed through the external thread of the air inlet screw and the internal thread of the motor shell, and the contradiction between explosion loss of a large pipe diameter and low efficiency of a small pipe diameter in the traditional design is solved by adopting the gas passage with multiple air inlet side holes for shunting and thread gap diffusion.

Description

Technical Field

[0001] The invention belongs to the technical field of underground coal mine ventilation safety, and particularly relates to a threaded explosion-proof intake device for an explosion-proof exhaust ventilator. Background Art

[0002] During the coal mining process, environments such as coal roadways, semi-coal rock roadways, rock roadways with gas outburst or ejection, and outburst coal seams all face the significant risk of gas accumulation and the possible formation of an explosive gas environment. Once the gas concentration in the roadway reaches the explosion limit, any potential ignition source may trigger a catastrophic explosion accident. Therefore, for equipment operating in such explosive gas environments, its safety performance requirements are extremely strict, and it must be ensured that the equipment can maintain an absolute safe state even under extreme conditions. To meet this requirement, equipment used in explosive environments usually needs to have two independent protection mechanisms to ensure that its equipment protection level (EPL) reaches the highest Ma level. At this level, even if one layer of protection fails, there are additional measures to ensure the reliable safety performance of the equipment. As a typical representative of such equipment, the Ma-level explosion-proof exhaust ventilator with positive pressure protection inside usually adopts a dual protection design of an explosion-proof enclosure and filling positive pressure non-explosive gas inside the enclosure to achieve its explosion-proof level.

[0003] However, in practical applications, there are a series of technical problems with the intake device for inflating the inside of the motor housing. Traditional intake devices often have difficulty finding a balance between the intake speed and the explosion-proof performance. Specifically, when the diameter of the intake pipe is designed to be relatively large, although it can meet the requirement of rapid intake inside the housing, an overly large diameter often exceeds the requirement of the explosion-proof gap (such as the maximum value specified in the GB3836 standard), resulting in the explosion-proof enclosure losing its explosion-proof function; conversely, if the diameter of the intake pipe is designed to be relatively small, although it can meet the requirement of the explosion-proof gap, the intake speed will become too slow to meet the actual demand for the intake speed inside the housing.

[0004] Therefore, developing an intake device that can not only ensure rapid intake but also ensure the explosion-proof performance is not lost is of great significance for improving the safety and reliability of explosion-proof exhaust ventilators. The proposal of this invention is precisely to solve this technical problem, aiming to provide an intake device that not only meets the intake speed requirement inside the housing but also conforms to the explosion-proof gap standard to meet the stringent requirements for the safety performance of equipment in explosive gas environments such as coal mining. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a threaded explosion-proof intake device for an explosion-proof exhaust ventilator to solve the technical problems existing in the intake devices of explosion-proof exhaust ventilators used in explosive gas environments such as existing coal roadways, semi-coal rock roadways, rock roadways with gas outburst, gas ejection areas, and outburst coal seams.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An explosion-proof extraction type ventilator threaded flameproof intake device, comprising:

[0008] An intake pipe, which is threadedly connected to one end of an intake screw;

[0009] The outer lower part of the intake screw is provided with an external thread, which cooperates with the internal thread of the motor housing to form a threaded flameproof surface; the upper end of the intake screw is an internal thread blind hole for connecting the intake pipe, and a plurality of intake side holes communicating with the threaded flameproof surface are provided at the lower end of the internal thread blind hole;

[0010] Gas sequentially enters the interior of the motor housing through the intake pipe, the internal thread blind hole and the intake side holes of the intake screw, and the threaded mating clearance.

[0011] Further, the effective number of engaged threads n in the threaded flameproof surface meets the requirements of the GB3836 standard, and the threaded clearance simultaneously meets the requirements of explosion-proof performance and intake speed.

[0012] Further, the number of intake side holes of the intake screw is 4 - 8, the hole diameter is 2 - 5 mm, and they are evenly distributed along the circumference.

[0013] Further, a first sealing ring is provided between the intake pipe and the intake screw to achieve sealing.

[0014] Further, a second sealing ring is provided between the intake screw and the motor housing to achieve sealing.

[0015] Further, the first sealing ring and the second sealing ring are made of fluororubber, and the temperature resistance range is -30°C to 200°C.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. Greatly reduce the technical difficulty of the internal positive pressure Ma type extraction ventilator

[0018] This intake device physically separates the motor flameproof housing from the external intake pipe with a threaded flameproof surface and clarifies the boundary, avoiding the subsequent safety mark certificate certification from also considering the intake pipe and the gas source part as part of the motor flameproof housing for joint inspection, greatly reducing the design, manufacturing and testing technical difficulties of the internal positive pressure type extraction ventilator, and facilitating the subsequent popularization and application of this type of ventilator.

[0019] 2. Practicality improvement of efficient intake and structural optimization

[0020] Innovative adoption of a gas passage with multi-intake side holes for shunt + threaded clearance diffusion: Multiple intake side holes (with a total flow area up to 120% of the intake pipe) are provided at the lower end of the intake screw blind hole, which can not only meet the rapid inflation demand but also avoid the risk of explosion failure, solving the contradiction between "explosion failure with large pipe diameter" and "low efficiency with small pipe diameter" in traditional designs.

[0021] 3. Industry application value of coal mine safety upgrade

[0022] This device provides core technical support for the internally pressurized Ma-class explosion-proof ventilator: By continuously exhausting dirty air to a dedicated return airway for 24 hours, it is expected to reduce the dust concentration in the airway by more than 70%, significantly improving the working environment of miners. Its modular design (such as replaceable intake screws) is compatible with different models of ventilators, successfully breaking through the restriction in the "Coal Mine Safety Regulations" on the prohibition of exhaust fans in coal roadways and gas outburst areas, providing key equipment guarantee for the construction of intelligent mines.

[0023] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. Brief description of the drawings

[0024] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:

[0025] Figure 1 It is a schematic structural diagram of a threaded explosion-proof intake device for an explosion-proof exhaust ventilator in an embodiment.

[0026] Reference numerals: intake pipe 1, first sealing ring 2, intake screw 3, internal thread blind hole 31, intake side hole 32, second sealing ring 4, motor housing 5. Detailed implementation manners

[0027] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following examples only illustrate the basic concept of the present invention schematically. Without conflict, the following examples and the features in the examples can be combined with each other.

[0028] Among them, the attached drawings are only for illustrative purposes, showing only schematic diagrams rather than physical diagrams, and should not be construed as limiting the present invention; in order to better illustrate the embodiments of the present invention, some components in the attached drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the attached drawings may be omitted.

[0029] In the attached drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the attached drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the attached drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] Please refer to Figure 1 , which is a threaded explosion-proof intake device for an explosion-proof extraction ventilator, including an intake pipe 1, an intake screw 3 and a motor housing 5. The intake pipe 1 is threadedly connected to the steel intake screw 3, and the external thread of the intake screw 3 and the internal thread of the motor housing 5 form a threaded explosion-proof surface.

[0031] The intake screw 3 is a steel component, and its lower part at the outer end is provided with an external thread, which cooperates with the internal thread of the motor housing 5 to form a threaded explosion-proof surface; the upper end of the intake screw 3 is an internal thread blind hole 31, and a plurality of intake side holes 32 are provided at the lower end of the internal thread blind hole 31.

[0032] The intake pipe 1 is threadedly connected into the internal thread blind hole 31 of the intake screw 3.

[0033] Furthermore, it further includes a first sealing ring 2 and a second sealing ring 4, which are respectively used for airtight sealing between the intake pipe 1 and the intake screw 3, and between the intake screw 3 and the motor housing 5; specifically, the first sealing ring 2 and the second sealing ring 4 are made of fluororubber, and the temperature resistance range is -30°C to 200°C.

[0034] The second sealing ring 4 is arranged between the nut of the intake screw 3 and the motor housing 5. An outwardly protruding annular protrusion is provided on the intake pipe 1, and the first sealing ring 2 is arranged between the annular protrusion and the upper surface of the intake screw 3, and the first sealing ring 2 is pressed against the upper surface of the intake screw 3 by the annular protrusion.

[0035] The gas passage of this intake device is as follows: Gas enters the housing through the intake pipe 1 → the internal thread blind hole 31 → the intake side hole 32 → the thread clearance. The thread clearance serves as both an explosion-proof barrier and a gas passage.

[0036] Furthermore, the effective number of mating thread turns of the thread flameproof joint is limited to n. When n meets the requirements of the GB3836 standard and the thread clearance meets the intake speed requirement, this intake device can meet the usage requirements.

[0037] Embodiment 1

[0038] Intake screw 3: The material is 304 stainless steel, the external thread is M24×1.5, the effective number of turns n = 6, and the thread clearance is 0.12 mm;

[0039] Intake side hole 32: 6 round holes with a diameter of 3 mm, evenly distributed along the circumference, and the total area is 42.4 mm 2 (The inner diameter of the intake pipe 1 is 8 mm, and the cross-sectional area is 50.3 mm 2 );

[0040] Working process: The positive-pressure gas enters the inner cavity of the motor housing evenly through the intake pipe → the screw inner cavity (internal thread blind hole) → the intake side hole for diffusion → the thread clearance.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A threaded explosion-proof air intake device for an explosion-proof exhaust fan, characterized in that: include: an air intake duct threadedly connected to one end of the air intake screw; The lower part of the outer end of the air intake screw is provided with an external thread, which cooperates with the internal thread of the motor housing to form a threaded explosion-proof surface; the upper end of the air intake screw is an internal threaded blind hole to connect the air intake pipe, and the lower end of the internal threaded blind hole is provided with a plurality of air intake side holes connected to the threaded explosion-proof surface; The gas enters the motor housing through the air intake pipe, the internal thread blind hole of the air intake screw, the air intake side hole, and the thread matching gap in sequence.

2. The explosion-proof exhaust fan threaded flameproof air intake device according to claim 1 is characterized in that: The effective thread number n of the threaded flameproof surface meets the requirements of GB3836 standard, and the thread gap meets the requirements of flameproof performance and air intake speed at the same time.

3. The threaded explosion-proof air intake device for an explosion-proof exhaust fan according to claim 1 is characterized in that: The number of the air intake side holes of the air intake screw is 4-8, the hole diameter is 2-5mm, and the holes are evenly distributed along the circumference.

4. The threaded explosion-proof air intake device for an explosion-proof exhaust fan according to claim 1 is characterized in that: A first sealing ring is provided between the air intake pipe and the air intake screw to achieve sealing.

5. The threaded explosion-proof air intake device for an explosion-proof exhaust fan according to claim 4 is characterized in that: A second sealing ring is provided between the air inlet screw and the motor housing to achieve sealing.

6. The threaded explosion-proof air intake device for an explosion-proof exhaust fan according to claim 5 is characterized in that: The first sealing ring and the second sealing ring are made of fluororubber with a temperature resistance range of -30°C to 200°C.

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