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

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 clearance type air inlet device which comprises a motor shell, a motor cover, an air inlet pipe, an air outlet pipe and a power source. The air inlet column is fixedly connected to the motor shell, the lower portion of the air inlet column is a polished rod with the outer diameter being d, the top end of the air inlet column is provided with a pressing plate, the lower portion of the air inlet column is inserted into the installation hole and is in clearance fit with the installation hole to form a spigot explosion-proof gap, and the upper end of the air inlet column is provided with an internal thread blind hole. At least two radially arranged air inlet side holes are formed in the bottom of the internal thread blind hole so as to be communicated with the seam allowance explosion-proof gap; and the air inlet pipeline is connected to the internal thread blind hole of the air inlet column through threads.

Description

Technical Field

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

[0002] During the coal mining process, environments such as coal headings, semi-coal rock headings, rock headings with gas outbursts or emissions, 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, the requirements for its safety performance 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 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 larger, 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 clearance (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 smaller, although it can meet the requirement of the explosion-proof clearance, the air intake speed will become too slow to meet the actual demand for the air intake speed inside the housing.

[0004] Therefore, the research and development of 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 clearance 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 clearance type air intake device for an explosion-proof exhaust ventilator to solve the problems raised in the background art.

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

[0007] An explosion-proof extraction type ventilator clearance type air intake device, comprising:

[0008] The motor housing, which is provided with a mounting hole having an inner diameter of D;

[0009] The air intake column, fixedly connected to the motor housing, the lower part of the air intake column is a smooth rod with an outer diameter of d, and a pressing plate is provided at the top. The lower part of the air intake column is inserted into the mounting hole and is in clearance fit to form a stop surface explosion-proof gap. An internal thread blind hole is provided at the upper end of the air intake column, and at least two radially arranged air intake side holes are machined at the bottom of the internal thread blind hole to communicate with the stop surface explosion-proof gap;

[0010] The air intake pipe, which is threadedly connected to the internal thread blind hole of the air intake column;

[0011] Wherein, the explosion-proof gap of the stop surface explosion-proof gap is ic, and the explosion-proof distance is H. The explosion-proof gap ic is controlled to be less than the maximum value of the explosion-proof gap specified in the GB3836 standard, and the explosion-proof distance H is greater than the minimum value of the explosion-proof distance specified in the GB3836 standard;

[0012] The total air intake area satisfies the formula:

[0013] S = π(D 2 -d 2 ) / 4

[0014] The equivalent air intake hole radius R is R = (D 2 -d 2 ) 0.5 / 2, and the R value is controlled to be greater than the lower limit value of the hole diameter corresponding to the target air intake speed.

[0015] Furthermore, the air intake column is made of steel material.

[0016] Furthermore, a first sealing ring is provided between the air intake pipe and the air intake column to achieve sealing.

[0017] Furthermore, a second sealing ring is provided between the air intake column and the motor housing to achieve sealing.

[0018] Furthermore, the first sealing ring and the second sealing ring are made of fluororubber material, and the temperature resistance range is -30°C to 200°C.

[0019] Furthermore, the air intake column is fixedly connected to the motor housing through connecting bolts.

[0020] Furthermore, the explosion-proof gap of the stop surface explosion-proof gap is ic, and the explosion-proof distance is H. The explosion-proof gap ic is controlled to be less than the maximum value of the explosion-proof gap specified in the GB3836 standard, and the explosion-proof distance H is greater than the minimum value of the explosion-proof distance specified in the GB3836 standard; the total air intake area satisfies the formula: S = π(D 2 -d2 ) / 4, the equivalent intake hole radius R is R = (D 2 -d 2 ) 0.5 / 2, and control the value of R to be greater than the lower limit of the aperture corresponding to the target intake speed.

[0021] Furthermore, the outer diameter of the lower part of the intake column is smaller than the inner diameter of the mounting hole of the motor housing to form a clearance fit, and by controlling the outer diameter of the lower part of the intake column and the inner diameter of the mounting hole of the motor housing, the size of the explosion-proof clearance ic is controlled.

[0022] The beneficial effects of the present invention are as follows:

[0023] First of all, the present invention successfully solves the technical problem between the intake speed and the explosion-proof performance of the intake device. Traditional intake devices often have difficulty finding a balance between the two, while the present invention through a unique design, that is, using the clearance fit between the intake column and the motor housing to form a stop explosion-proof clearance, and precisely controlling the explosion-proof clearance ic and the explosion-proof distance H, not only meets the need for rapid intake, but also ensures the explosion-proof performance. This design cleverly avoids the problem of the explosion-proof housing losing explosion due to too large an intake pipe diameter, and at the same time solves the problem of slow intake speed due to too small an intake pipe diameter.

[0024] Secondly, the present invention provides strong support for the research, development, promotion and application of the Ma-level explosion-proof extraction ventilator with internal positive pressure protection in terms of technology. Through the design of replacing the straight through hole with an annular gap, the present invention can achieve an equivalent flux of Φ6.36mm on the Φ40mm intake column, effectively solving the contradiction between the intake speed and the explosion-proof requirements. At the same time, the multi-hole shunt design reduces the air flow speed, reduces the risk of friction static electricity, and further improves the safety of the equipment. These technological innovations not only optimize the performance of the intake device, but also provide more reliable guarantee for the ventilation safety in coal mines.

[0025] Finally, the air inlet device of the present invention enables the overall explosion-proof level of the ventilator to reach Ma level, providing strong support for the promotion and application of Ma-level equipment. This not only helps to reduce roadway dust and keep the air fresh, creating good labor and health conditions for coal miners, but also further proves the reliability and practicality of the present invention in actual engineering.

[0026] 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. Description of the Drawings

[0027] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail and preferably below in conjunction with the accompanying drawings, where:

[0028] Figure 1 It is a schematic structural diagram of a clearance-type air intake device of an explosion-proof exhaust ventilator in the embodiment.

[0029] Reference numerals: air intake pipe 1, sealing ring 2, air intake column 3, internal thread blind hole 31, air intake side hole 32, sealing ring 4, motor housing 5, connecting bolt 6. Specific embodiments

[0030] The following illustrates the embodiments of the present invention through specific examples. 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 different specific embodiments. 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 schematically. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0031] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation on 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 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 drawings may be omitted.

[0032] 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 positional relationship, they are based on the orientation or positional 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 positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation on 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.

[0033] Please refer to Figure 1 , which is a clearance-type air intake device of an explosion-proof exhaust ventilator, and includes the following components:

[0034] Air intake pipe 1: Made of 304 stainless steel, the inner wall is polished by mirror to reduce the air flow resistance;

[0035] Intake column 3: Made of 45# steel after quenching and tempering treatment, with an internal threaded blind hole 31 machined at the upper end. Eight intake side holes 32 arranged in a spiral array are provided at the lower end of the internal threaded blind hole 31 to achieve multi-directional diffusion of air flow; in another embodiment, the intake side holes 32 can also be arranged in a circumferential array;

[0036] Stopper explosion-proof gap: The lower end of the intake column 3 is a smooth rod structure, forming a stopper explosion-proof gap with the mounting hole of the motor housing 5. The explosion-proof gap of the stopper explosion-proof gap is ic, and the explosion-proof distance is H (controlling the explosion-proof gap to be lower than the maximum value specified in GB3836, and the explosion-proof distance is greater than the minimum value specified in GB3836);

[0037] Sealing assembly: Adopts a fluororubber O-ring seal, with a temperature resistance range of -30°C to 200°C, and the compression rate is controlled at 18±2% to ensure airtightness under high-pressure conditions;

[0038] The sealing assembly 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 column 3, and between the intake column 3 and the motor housing 5;

[0039] The second sealing ring 4 is arranged between the pressing plate at the top of the intake column 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 column 3, and the first sealing ring 2 is pressed against the upper surface of the intake column 3 by the annular protrusion.

[0040] Connecting bolt 6: Adopts an M10×1.5 high-strength bolt, with an installation torque of 45±3 N·m to provide a stable mechanical connection.

[0041] The assembly steps of the explosion-proof extraction type ventilator clearance type intake device are as follows: Insert the intake column 3 into the installation hole of the motor housing 5, and arrange the second sealing ring 4 between the pressing plate at the top of the intake column 3 and the motor housing 5, and then fix the intake column 3 to the motor housing 5 through the bolt 6, so that the intake column 3 and the motor housing 5 are sealed and fixedly connected;

[0042] Thread-connect the intake pipe 1 with the intake column 3, and arrange the first sealing ring 2 between the annular protrusion and the upper surface of the intake column 3.

[0043] The gas flow path of the explosion-proof extraction type ventilator clearance type intake device is: intake pipe 1 → intake column inner cavity → intake side hole → explosion-proof gap → inside the motor housing. Calculate the total intake area through the following formula:

[0044] S = π(D 2 -d 2 ) / 4

[0045] Where S is the total intake area, D is the inner diameter of the flameproof hole (mounting hole) in the motor housing, d is the outer diameter of the lower part of the intake column, and π is the ratio of the circumference of a circle to its diameter. The equivalent intake hole radius is:

[0046] R = (D 2 - d 2 ) 0.5 / 2

[0047] Where R is the equivalent intake hole radius. When R is greater than the required value, the intake speed requirement can be met.

[0048] Specifically, in this embodiment, the inner diameter D of the mounting hole in the motor housing is set to 40.5 mm, the outer diameter d of the lower end of the intake column is set to 40 mm, the flameproof gap ic is 0.5 mm, and the flameproof distance H can be adaptively designed as needed (such as H = 25 mm). It is calculated that S = 31.67 mm 2 , R = 3.18 mm, which is equivalent to the flow capacity of a Φ6.36 mm straight pipe and can meet the design requirements of a Φ6 mm intake hole.

[0049] In another embodiment, the inner diameter D of the mounting hole in the motor housing and the outer diameter d of the lower end of the intake column can be correspondingly adjusted according to the need for intake speed to meet the requirements.

[0050] 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 spirit and scope of the present technical solution, and they should all be covered by the scope of the claims of the present invention.

Claims

1. An explosion-proof exhaust fan gap type air intake device, characterized in that: include: A motor housing having a mounting hole with an inner diameter of D; An air intake column is fixedly connected to the motor housing, the lower part of the air intake column is a light rod with an outer diameter of d, and a pressure plate is provided at the top. The lower part of the air intake column is inserted into the mounting hole and is clearance-matched to form a stopper explosion-proof gap. The upper end of the air intake column is provided with an internal threaded blind hole, and the bottom of the internal threaded blind hole is processed with at least two radially arranged air intake side holes to connect the stopper explosion-proof gap; The air intake pipe is connected to the internal threaded blind hole of the air intake column through threads.

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

3. The explosion-proof exhaust fan gap type air intake device according to claim 1, characterized in that: A first sealing ring is provided between the air intake pipe and the air intake column to achieve sealing.

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

5. The explosion-proof exhaust fan gap type air intake device according to claim 4, 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 gap type air intake device according to claim 1, characterized in that: The air intake column is fixedly connected to the motor housing via connecting bolts.

7. The explosion-proof exhaust fan gap type air intake device according to claim 1, characterized in that: The flameproof gap of the stopper flameproof gap is ic, the flameproof distance is H, the flameproof gap ic is controlled to be smaller than the maximum value of the flameproof gap specified in GB3836 standard, and the flameproof distance H is greater than the minimum value of the flameproof distance specified in GB3836 standard; The total intake area satisfies the formula: S=π(D 2 -d 2 ) / 4 The equivalent air inlet radius R is R = (D 2 -d 2 ) 0.5 / 2, and control the R value to be greater than the lower limit of the aperture corresponding to the target intake speed.

8. The explosion-proof exhaust fan gap type air intake device according to claim 7, characterized in that: The outer diameter of the lower part of the air intake column is smaller than the inner diameter of the motor housing mounting hole to form a clearance fit, and the size of the explosion-proof gap ic is controlled by controlling the outer diameter of the lower part of the air intake column and the inner diameter of the motor housing mounting hole.

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