Anti-explosion draw-out type ventilator gap type air inlet device

Abstract

The invention belongs to the technical field of coal mine underground ventilation safety, and particularly relates to an anti-explosion draw-out type ventilator gap type air inlet device which comprises a motor shell, an air inlet pipe, an air outlet pipe and a motor, the lower part of the outer end of the air inlet screw is provided with an external thread matched with the internal thread of the motor shell, so that a thread explosion-proof joint surface is formed; an internal thread blind hole is formed in the upper end of the air inlet screw, and at least two air inlet gaps with the length of b, the width of ic and the depth of H are machined in the bottom of the internal thread blind hole; and the air inlet pipeline is connected to the internal thread blind hole of the air inlet screw through threads. A multi-gap air inlet structure is adopted, a traditional single-diameter pipeline is replaced by a plurality of micro gaps in the bottom of the air inlet screw, the strict requirement of the GB3836 standard for an explosion-proof gap is met (explosion loss is avoided), the air supply efficiency is remarkably improved through the equivalent air inlet area, and the contradiction between the air supply efficiency and safety in explosion-proof equipment is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of underground coal mine ventilation safety, and particularly relates to a slit-type air 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 emission or outburst, 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 internal positive pressure protection usually adopts a dual protection design of an explosion-proof enclosure and filling non-explosive gas with positive pressure inside the enclosure to achieve its explosion-proof level.

[0003] However, in practical applications, there are a series of technical problems with the air intake device for inflating the inside of the motor housing. Traditional air intake devices often have difficulty finding a balance between the air intake speed and the explosion-proof performance. Specifically, when the diameter of the intake pipe is designed to be large, although it can meet the requirement of rapid air 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 small, although it can meet the requirement of the explosion-proof gap, the air intake speed will become too slow to meet the actual demand for the air intake speed inside the housing.

[0004] Therefore, developing an air intake device that can not only ensure rapid air intake but also ensure the explosion-proof performance is of great significance for improving the safety and reliability of explosion-proof exhaust ventilators. The proposal of the present invention is precisely to solve this technical problem, aiming to provide an air intake device that not only meets the air intake speed requirement inside the housing but also complies with 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 slit-type air intake device for an explosion-proof exhaust ventilator to solve the technical problems existing in the air 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 outburst areas, and outburst coal seams.

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

[0007] An air intake device with a gap type for an explosion-proof extraction ventilator, comprising:

[0008] A motor housing, the inner wall of which is provided with internal threads;

[0009] An air intake screw, the lower part of the outer end of which is provided with external threads adapted to the internal threads of the motor housing to form a threaded explosion-proof joint surface; the upper end of the air intake screw is provided with an internal threaded blind hole, and at least two air intake gaps with a length of b, a width of ic, and a depth of H are machined at the bottom of the internal threaded blind hole;

[0010] An air intake pipe, which is threadedly connected to the internal threaded blind hole of the air intake screw;

[0011] Wherein, the width ic of the air intake gap is less than the maximum value of the explosion-proof gap specified in the GB3836 standard, the depth H is greater than the minimum value of the explosion-proof distance specified in the GB3836 standard, the total air intake area is S = n × b × i, and the equivalent air intake hole radius R satisfies R = (n × b × ic / π) 0.5 , and the R value is greater than the lower limit value of the aperture corresponding to the target air intake speed.

[0012] Further, the air intake screw is made of steel material.

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

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

[0015] Further, 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.

[0016] Further, the number n of the air intake gaps is 4 to 12, the length b of a single air intake gap is 5 to 20 mm, the width ic is 0.3 to 0.5 mm, and the depth H is 15 to 30 mm.

[0017] Further, the air intake pipe is externally connected to a positive pressure gas source, and the gas enters the interior of the motor housing through the air intake gaps of the air intake screw to maintain a positive pressure non-explosive gas environment inside the motor housing.

[0018] Further, the width ic of the air intake gap is less than the maximum value of the explosion-proof gap specified in the GB3836 standard, the depth H is greater than the minimum value of the explosion-proof distance specified in the GB3836 standard, the total air intake area is S = n × b × i, and the equivalent air intake hole radius R satisfies R = (n × b × ic / π) 0.5, and control the R value to be greater than the lower limit value of the aperture corresponding to the target intake air speed.

[0019] The beneficial effects of the present invention are as follows:

[0020] The core innovation of the present invention is to adopt a multi-gap intake structure, replacing the traditional single-diameter pipeline with multiple micro-gaps (width ic ≤ 0.5 mm, depth H ≥ 15 mm) at the bottom of the intake screw. This not only meets the stringent requirements of the GB3836 standard for explosion-proof gaps (to avoid explosion failure), but also significantly improves the air supplement efficiency through the equivalent intake area (S = n × b × ic). Compared with the traditional scheme, this design breakthroughly solves the contradiction between explosion-proof and intake air speed: when the equivalent intake hole radius R ≥ 1.5 mm, its air supplement speed can reach more than 36 times that of a common small-aperture pipeline (diameter ≤ 0.5 mm), and the independent explosion-proof characteristics of each gap ensure the dual safety protection (EPL Ma level) of the equipment in an explosive environment.

[0021] By precisely controlling the number of gaps (n = 4 - 12), length (b = 5 - 20 mm), and width (ic = 0.2 - 0.5 mm), the present invention achieves a balance between performance and cost. For example, when ic = 0.4 mm and H = 20 mm, the total intake area S = 16 - 32 mm2 (corresponding to R = 2.26 - 3.19 mm), which can meet the requirements of explosion-proof ventilators with different powers. In addition, the threaded explosion-proof joint surface between the intake screw and the motor housing combined with double sealing rings further simplifies the assembly process, reduces the maintenance cost, and has a compact overall structure, suitable for narrow spaces in coal mines.

[0022] This technical solution provides key support for the research and development of an intrinsically pressurized Ma-level explosion-proof ventilator, and both its safety (compliant with the GB3836.2 standard) and efficiency (intake air speed ≥ 5 m 3 / min) can be satisfied simultaneously. In practical applications, the modular design of this device can also be extended to Class II explosive environments such as chemical industry and gas, promoting the technological upgrade and standardization process of explosion-proof equipment, and having broad economic and social benefits.

[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 1Top view of the intake screw in the embodiment;

[0026] Figure 2 Cross-sectional view of a slit-type intake device of an explosion-proof extractable ventilator in the embodiment (the cross-sectional direction is Figure 1 the A-A direction in

[0027] Reference numerals: intake pipe 1, first sealing ring 2, intake screw 3, internal thread blind hole 31, intake slit 32, second sealing ring 4, motor housing 5. Detailed implementation manners

[0028] The following uses specific specific examples to 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 embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0029] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and cannot be understood as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0030] In the 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 position relationship, it is based on the orientation or position relationship shown in the drawings. It is 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 position relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation to 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.

[0031] Please refer to Figures 1 to 2 , which is a slit-type intake device of an explosion-proof extractable ventilator, including the following components:

[0032] Intake pipe 1: externally connected to a positive pressure air source and connected to the intake screw 3 through threads;

[0033] Intake screw 3: A steel component with external threads at the lower part of the outer end (forming a threaded explosion-proof surface when connected to the internal threads of the motor housing 5), and an internal threaded blind hole 31 at the upper end. Multiple intake slots 32 are machined at the bottom of the internal threaded blind hole 31 to communicate with the inner cavity of the motor housing;

[0034] Motor housing 5: The intake screw 3 is embedded therein through threaded connection to form an explosion-proof cavity;

[0035] Sealing structure: 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, with a temperature resistance range of -30°C to 200°C;

[0036] 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.

[0037] Key design parameters:

[0038] Size of the intake slot 32: The width (ic) is less than the maximum value of the explosion-proof gap specified in GB3836 (its specific value can be adjusted adaptively according to the size specifications of the motor housing, such as ≤0.5 mm), and the depth (H) is greater than the minimum value of the explosion-proof distance specified in the GB3836 standard (its specific value can be adjusted adaptively according to the size specifications of the motor housing, such as ≥15 mm);

[0039] Total intake area: Calculated by superimposing multiple slots, the formula is:

[0040] S = n × b × ic

[0041] In the formula, S is the total intake area, n is the number of slots, b is the length of the slot, ic is the width of the slot, and its equivalent intake hole radius is:

[0042] R = (n * b * ic / π) 0.5

[0043] In the formula, R is the equivalent intake hole radius, n is the number of slots, b is the length of the slot, ic is the width of the slot, and π is the pi. When R is greater than or equal to the required value of the target intake speed, the intake speed requirement can be met.

[0044] The working principle is as follows:

[0045] Positive-pressure gas enters the internal threaded blind hole 31 of the intake screw 3 through the intake pipeline 1, and then enters the interior of the motor housing 5 through multiple intake gaps 32 at the bottom. Since the width ic of each gap strictly complies with the explosion-proof standard, and the total area of the superimposed multiple intake gaps 32 is equivalent to that of a large-aperture pipeline, the intake efficiency is improved while ensuring the explosion-proof performance.

[0046] Embodiment 1

[0047] Taking a certain type of Ma-class explosion-proof ventilator as an example:

[0048] Parameters of the intake screw 3: Four intake gaps 32 are machined (n = 4), the length b of a single intake gap is 10 mm, the width ic is 0.4 mm, and the depth H is 20 mm (meeting the GB3836 standard);

[0049] Total intake area:

[0050] S = 4 × 10 mm × 0.4 mm = 16 mm 2

[0051] Equivalent intake hole radius:

[0052] R = (16 / π) 0.5 ≈2.26 mm

[0053] It is equivalent to a round hole with a diameter of 4.52 mm, and the intake capacity is significantly higher than that of traditional small-aperture holes (such as 0.3 mm).

[0054] Embodiment 2

[0055] For high-flow demand scenarios:

[0056] Increase the number of gaps to 8 (n = 8), the length b of a single gap is 15 mm, the width ic is 0.3 mm, and the depth H is 25 mm;

[0057] The total intake area is increased to 36 mm 2 , and the equivalent radius R ≈ 3.39 mm, meeting the demand for a higher air supplement rate.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. 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. An explosion-proof exhaust fan slit-type air intake device, characterized in that: include: The motor housing has an inner wall provided with an internal thread; The air intake screw has an outer thread at the lower part of the outer end adapted to the inner thread of the motor housing to form a threaded flameproof joint surface; the upper end of the air intake screw is provided with an inner thread blind hole, and the bottom of the inner thread blind hole is processed with at least two air intake gaps with a length of b, a width of ic, and a depth of H; an air intake duct threadedly connected to the internally threaded blind hole of the air intake screw; The width ic of the air inlet gap is smaller than the maximum value of the flameproof gap specified in GB3836 standard, and the depth H is larger than the minimum value of the flameproof distance specified in GB3836 standard.

2. The explosion-proof exhaust fan slit-type air intake device according to claim 1 is characterized in that: The air inlet screw is made of steel material.

3. The explosion-proof exhaust fan slit-type air intake device 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.

4. The explosion-proof exhaust fan slit-type air intake device according to claim 3 is characterized in that: A second sealing ring is provided between the air inlet screw and the motor housing to achieve sealing.

5. The explosion-proof exhaust fan slit-type air intake device according to claim 4 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.

6. The explosion-proof exhaust fan slit-type air intake device according to claim 1, characterized in that: The number n of the air intake slits is 4 to 12, the length b of a single air intake slit is 5 to 20 mm, the width ic is 0.3 to 0.5 mm, and the depth H is 15 to 30 mm.

7. The gap-type air intake device of the explosion-proof exhaust ventilator according to any one of claims 1 to 6, characterized in that: The air intake pipe is externally connected to a positive pressure air source, and the gas enters the motor housing through the air intake gap of the air intake screw to maintain a positive pressure non-explosive gas environment in the motor housing.

8. The explosion-proof exhaust fan slit-type air intake device according to claim 1 is characterized in that: The width ic of the air intake gap is less than the maximum value of the flameproof gap specified in GB3836 standard, the depth H is greater than the minimum value of the flameproof distance specified in GB3836 standard, the total air intake area is S = n × b × i, and the equivalent air intake hole radius R satisfies R = (n × b × ic / π) 0.5 , and control the R value to be greater than the lower limit of the aperture corresponding to the target intake speed.

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