Ma protection level explosion-proof draw-out type ventilator with IP68 protection level of explosion-proof motor

Abstract

The invention belongs to the field of coal mine underground ventilation safety, and relates to an Ma protection level explosion-proof draw-out type ventilator with an IP68 protection level of an explosion-proof motor, which comprises a motor sealing cavity and a junction box sealing cavity, the junction box sealing cavity is an inner cavity of the junction box, an air inlet valve and an exhaust valve which are communicated with the inner cavity of the junction box are arranged on the junction box, and a wiring terminal and a horn mouth are arranged on the junction box; the motor sealing cavity comprises an inner cavity of the explosive-proof motor and an inner cavity of a motor wire outlet pipe connected to the explosive-proof motor, the motor wire outlet pipe abuts against and is in sealed connection with the side, provided with the wiring terminal, of the junction box, and the end, penetrating out of the junction box, of the wiring terminal is inserted into the motor wire outlet pipe and is connected with a cable electrically connected with the explosive-proof motor; and the other end of the wiring terminal is connected with an external cable introduced from the horn mouth. The protection grade of the anti-explosion draw-out type ventilator is improved from Mb to Ma, and technical obstacles are cleared away for the use of the anti-explosion draw-out type ventilator in coal roadways, half-coal rock roadways, rock roadways with gas emission, gas emission areas and outburst coal seams.

Description

Technical Field

[0001] The invention belongs to the field of underground ventilation safety in coal mines, and relates to an explosion-proof extraction ventilator with a Ma protection level and an explosion-proof motor with an IP68 protection level. Background Art

[0002] Article 163 of the Coal Mine Safety Regulations (2022 Edition) stipulates that tunneling must be ventilated with full mine air pressure or local ventilators. When coal tunnels, semi-coal-rock tunnels, and rock tunnels with gas gushing are ventilated with local ventilators, the pressure-in type should be adopted, and the extraction type shall not be adopted (compressed air and hydraulic ejectors are not subject to this restriction); if a mixed type is adopted, safety measures must be formulated. When local ventilators are used for ventilation in gas-gushing areas and protruding coal seams, the pressure-in type must be adopted. According to the requirements of the above clauses, local extraction ventilators using electric motors as power sources are not allowed in coal tunnels, semi-coal-rock tunnels, and rock tunnels with gas gushing; at the same time, any type of local extraction ventilators are not allowed in gas-gushing areas and protruding coal seams. The reason for making the above clauses is that there is a risk of gas gushing / gushing in coal tunnels, semi-coal-rock tunnels, rock tunnels with gas gushing, gas gushing areas, gas gushing areas, and protruding coal seams. When the gas explosion concentration is reached in the tunnel, an explosive gas environment will be formed. At present, all motor-driven exhaust fans used in coal mines have motors with explosion-proof type Ex dbⅠMb and equipment protection level (EPL) Mb. They are only protected by flameproof enclosures. When gas gushes / sprays in the exhaust fan application scenario to form an explosive gas environment, explosive gas will be densely distributed around the motor and enter the motor through the flameproof gap. At this time, if sparks or other ignition sources are generated inside the motor, the gas inside the motor will explode, resulting in a certain probability of the motor shell failing to explode, igniting the explosive environment and eventually causing a large-scale gas explosion accident in the underground tunnel. Therefore, according to the provisions of the Mb protection level, when the motor is in an explosive gas environment, it must be shut down. Therefore, this type of exhaust fan cannot realize the function of 24-hour uninterrupted operation to continuously supply air to the working face. Therefore, the "Coal Mine Safety Regulations" restrict the use of motor-driven exhaust fans in places where explosive gases exist.

[0003] At present, the explosion-proof pressure-type ventilators used in large quantities to supply air to the working face will cause serious dust and air pollution at the air-using locations, and cause large-scale pollution to the tunnels flowing through, seriously affecting the occupational health of the workers. If local exhaust fans can be used in the underground tunnels of coal mines, the dust pollution level at the air-using locations can be significantly reduced, and the dirty air at the locations can be extracted and transported to the dedicated return air tunnel through the wind tube, avoiding the large-scale pollution caused by the dirty air flowing through the rest of the tunnel, which is conducive to maintaining the non-explosiveness of the tunnel air and creating good labor hygiene conditions. However, for equipment used in explosive gas environments, absolute safety is required in principle. Therefore, equipment operating in explosive environments generally needs to have two independent layers of protection, and the equipment protection level (EPL) reaches the Ma level (when one of them fails, there are still additional measures to ensure its reliable safety performance). However, my country's coal mines do not yet have exhaust fans driven by motors with this protection level.

[0004] In view of the advantages of using local exhaust fans and the existing safety issues, it is of great significance to develop an explosion-proof exhaust fan with IP68 protection grade and Ma protection level. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide an explosion-proof exhaust fan with Ma protection level and explosion-proof motor IP68 protection grade, so as to solve the safety problems existing in the existing explosion-proof exhaust fans, and then solve the occupational health problems such as serious dust, air pollution, and tunnel pollution caused by the current explosion-proof push-in fans supplying air to the working surface through the explosion-proof exhaust fan.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] An explosion-proof extraction fan with Ma protection level and explosion-proof motor IP68 protection level, comprising a fan housing, a flameproof motor arranged in the fan housing, an impeller drivingly connected to the flameproof motor, and a junction box for controlling the flameproof motor, and also comprising a motor sealing chamber and a junction box sealing chamber;

[0008] The junction box sealed cavity is the inner cavity of the junction box, and an air inlet valve and an exhaust valve connected to the inner cavity of the junction box are provided on the junction box to introduce and exhaust gas into the junction box sealed cavity, and a trumpet mouth for introducing an external cable and a terminal that penetrates the junction box and is sealed and connected are provided on the junction box to realize electrical connection between the external cable and the junction box, and between the junction box and the flameproof motor on the basis that the junction box sealed cavity is not connected to the motor sealed cavity and the external explosive environment;

[0009] The motor sealed cavity includes the inner cavity of the flameproof motor and the inner cavity of the motor outlet tube connected to the flameproof motor. The motor outlet tube is sealed and abutted against one side of the junction box where the terminal is provided, and one end of the terminal passing through the junction box is inserted into the motor outlet tube.

[0010] Furthermore, the flameproof motor includes a motor winding and a motor housing for accommodating the motor winding, the motor housing includes a motor housing body and a front cover plate and a rear cover plate installed at both ends of the motor housing body, and the motor rotating shaft passes through the front cover plate and is connected to the impeller.

[0011] Furthermore, a front static seal and a rear static seal are respectively provided between the front cover plate and the rear cover plate and the motor housing body, and a motor rotating shaft dynamic seal is provided between the motor rotating shaft and the front cover plate.

[0012] Furthermore, the motor outlet pipe is connected to and passes through the motor housing body to communicate with the inner cavity of the flameproof motor, and an outlet pipe static seal is provided between the motor outlet pipe and the motor housing body.

[0013] Furthermore, the flameproof motor includes a motor winding and a motor housing for accommodating the motor winding, the motor housing includes a motor housing body and a rear end cover plate installed at an open end of the motor housing body, and the motor rotating shaft passes through the motor housing body toward the end away from the rear end cover plate to connect to the impeller.

[0014] Furthermore, the junction box includes a junction box shell and a junction box cover plate buckled on the junction box shell, and the connection terminals are arranged at the bottom of the junction box shell, and the outer side of the bottom of the junction box shell is abutted and connected with the end face of the motor outlet pipe to seal the opening of the motor outlet pipe.

[0015] Furthermore, a junction box static seal is provided at the connection between the junction box housing and the motor outlet pipe to prevent gas from entering the motor sealing cavity from the connection between the junction box housing and the motor outlet pipe.

[0016] Furthermore, a junction box cover plate static seal is provided between the junction box housing and the junction box cover plate.

[0017] Furthermore, a terminal static seal is provided at the terminal to prevent gas from entering the motor sealing cavity from the terminal.

[0018] The beneficial effects of the present invention are:

[0019] The invention provides an explosion-proof motor IP68 protection level Ma protection level explosion-proof exhaust ventilator. On the basis of the common explosion-proof exhaust ventilator, a motor sealing chamber and a junction box sealing chamber are additionally provided. The electrical connection with the explosion-proof motor can be realized on the basis that the junction box is not connected with the motor sealing chamber, thereby ensuring the complete sealing of the explosion-proof motor. An air intake valve and an exhaust valve are arranged on the junction box, so that after the external cable is connected with the junction box, the explosion gas in the junction box sealing chamber is discharged in time, and fresh gas is introduced, and the connection between the external gas and the junction box sealing chamber is isolated, instead of relying solely on the explosion-proof shell for protection, thereby improving the protection level of the explosion-proof exhaust ventilator from Mb to Ma, clearing the technical obstacles for its use in coal lanes, semi-coal-rock lanes, rock lanes with gas gushing, gas gushing areas and protruding coal seams, and it can operate 24 hours uninterruptedly to continuously supply air to the working face;

[0020] Secondly, by using explosion-proof exhaust fans in underground coal mine tunnels, the polluted air in local air-using locations can be extracted and transported to a dedicated return air tunnel through wind ducts, avoiding large-scale pollution caused by polluted air flowing through other locations in the tunnel, which is beneficial to maintaining the non-explosiveness of the tunnel air and creating good working and hygiene conditions.

[0021] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0023] Figure 1 This is a schematic structural diagram of an explosion-proof exhaust ventilator with a Ma protection level and an explosion-proof motor with an IP68 protection level in Example 1;

[0024] Figure 2 It is a partial structural schematic diagram of the junction box in Example 1;

[0025] Figure 3 This is a schematic structural diagram of an explosion-proof exhaust fan with a Ma protection level and an explosion-proof motor with an IP68 protection level in Example 2.

[0026] Figure numerals: front end static seal 1, motor rotating shaft dynamic seal 2, motor housing 3, motor housing body 31, front end cover plate 32, rear end cover plate 33, rear end static seal 4, motor outlet pipe 5, outlet pipe static seal 6, junction box static seal 7, junction box 8, junction box housing 81, junction box cover plate 82, exhaust valve 9, junction box cover plate static seal 10, intake valve 11, terminal static seal 12, terminal 13. DETAILED DESCRIPTION

[0027] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0028] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0029] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which 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 operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] See also Figure 1-2, is a flameproof motor with IP68 protection level and Ma protection level explosion-proof exhaust fan. On the basis of ordinary explosion-proof exhaust fan, safety facilities are added to the flameproof motor and junction box, and the safety facilities include a motor sealing chamber and a junction box sealing chamber. The ordinary explosion-proof exhaust fan includes a fan flow channel formed by a fan housing, a flameproof motor arranged in the fan housing, an impeller connected to the motor rotating shaft of the flameproof motor, and a junction box for controlling the flameproof motor, and the junction box is usually used as a fan power switch controller.

[0031] The motor sealed cavity is composed of the inner cavity of the motor housing 3 (i.e., the inner cavity of the flameproof motor) and the inner cavity of the motor outlet pipe 5. The motor outlet pipe 5 is connected to the inner cavity of the motor housing 3 and is sealed and abutted with the side of the junction box housing 81 having the wiring terminal 13 to form a motor sealed cavity, which is used to isolate the electrical components such as the motor winding of the flameproof motor from the explosive gas in the fan flow channel, and a cable connecting the motor winding and the wiring terminal 13 is arranged through the motor outlet pipe 5;

[0032] Specifically, the motor housing 3 includes a motor housing body 31 for accommodating the motor winding and a front cover plate 32 and a rear cover plate 33 installed at both ends of the motor housing body. The motor rotating shaft of the flameproof motor passes through the front cover plate 32 and is connected to the impeller. The motor outlet pipe 5 is connected to the motor housing body 31.

[0033] Preferably, a front end static seal 1 and a rear end static seal 4 are respectively provided between the front end cover plate 32 and the rear end cover plate 33 and the motor housing body 31, a motor rotating shaft dynamic seal 2 is provided between the motor rotating shaft and the front end cover plate, and a wire outlet pipe static seal 6 is provided between the motor wire outlet pipe 5 and the motor housing body, so that the motor housing 3 forms a sealed cavity.

[0034] The junction box sealed cavity is the inner cavity of the junction box 8, and the junction box 8 includes a junction box shell 81 and a junction box cover 82 buckled on the junction box shell 81. A trumpet mouth (not shown) for connecting an external cable is provided on the side of the junction box shell 81, and a connection terminal 13 for connecting a cable in the motor outlet pipe 5 is provided at the bottom of the junction box shell 81;

[0035] The key is that the junction box 8 is also provided with an air inlet valve 11 and an exhaust valve 9 connected to the inner cavity of the junction box 8, so as to introduce fresh gas into the sealed cavity of the junction box and pressurize it, thereby isolating the terminal 13 and the cable connector from the explosive gas in the environment.

[0036] The wiring terminal 13 penetrates the junction box housing 81 and is inserted into the motor outlet pipe 5, and the bottom of the junction box housing 81 is in contact with the motor outlet pipe 5 to seal the opening of the motor outlet pipe 5;

[0037] Specifically, one end of the terminal extending out of the junction box is inserted into the motor outlet pipe and connected to the cable arranged in the motor outlet pipe and electrically connected to the flameproof motor, and the other end is connected to the cable introduced from the bell mouth (not shown) to achieve electrical connection between the external cable and the junction box, and between the junction box and the flameproof motor without the sealed cavity of the junction box being connected to the sealed cavity of the motor.

[0038] Preferably, a junction box cover plate static seal 10 is provided between the junction box housing 81 and the junction box cover plate 82 to ensure the sealing performance of the junction box sealing cavity.

[0039] A terminal static seal 12 is provided at the terminal 13 , and a terminal box static seal 7 is provided at the contact connection between the bottom of the terminal box housing 81 and the motor outlet pipe 5 to ensure the sealing of the motor sealing cavity.

[0040] Specifically, a trumpet mouth for introducing external cables is provided on the side of the junction box housing 81, and a cable static seal is provided inside the trumpet mouth to prevent external gas from entering the junction box sealing cavity when the cables are connected; and the cables are electrically connected to the wiring terminals 13. The static seal and dynamic seal mentioned in this embodiment are generally provided by sealing rings or other structures that can achieve corresponding functions.

[0041] The installation and starting methods of the above explosion-proof exhaust ventilator are as follows:

[0042] Open the junction box cover and connect the external cable to the cable connector in the junction box. When the external cable wiring is completed and the junction box cover 82 is closed, open the air inlet valve 11 and the exhaust valve 9, and connect the air inlet valve 11 to a fresh air source such as compressed air. After the specified time, close the exhaust valve 9 first, then close the air inlet valve 11, and finally start the fan motor.

[0043] Example 2

[0044] See also Figure 3 The difference between this embodiment and embodiment 1 is that the motor housing 3 includes a motor housing body 31 for accommodating the motor winding and a rear end cover plate 33 installed at the open end of the motor housing body 31, and the motor rotating shaft passes through the motor housing body 31 toward the end away from the rear end cover plate 33 to connect to the impeller.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. An explosion-proof exhaust fan with Ma protection level and flameproof motor IP68 protection level, comprising a fan housing, a flameproof motor arranged in the fan housing, an impeller drivingly connected to the flameproof motor, and a junction box for controlling the flameproof motor, characterized in that: It also includes a motor sealed cavity and a junction box sealed cavity; The junction box sealed cavity is the inner cavity of the junction box, and an air inlet valve and an exhaust valve connected to the inner cavity of the junction box are provided on the junction box to introduce and exhaust gas into the junction box sealed cavity, and a trumpet mouth for introducing an external cable and a terminal that penetrates the junction box and is sealed and connected are provided on the junction box to realize electrical connection between the external cable and the junction box, and between the junction box and the flameproof motor on the basis that the junction box sealed cavity is not connected to the motor sealed cavity and the external explosive environment; The motor sealed cavity includes the inner cavity of the flameproof motor and the inner cavity of the motor outlet tube connected to the flameproof motor. The motor outlet tube is sealed and abutted against one side of the junction box where the terminal is provided, and one end of the terminal passing through the junction box is inserted into the motor outlet tube.

2. The explosion-proof exhaust ventilator with Ma protection level and explosion-proof motor IP68 protection level according to claim 1 is characterized in that: The flameproof motor comprises a motor winding and a motor housing for accommodating the motor winding. The motor housing comprises a motor housing body and a front cover plate and a rear cover plate installed at both ends of the motor housing body. The motor rotating shaft passes through the front cover plate and is connected to the impeller.

3. The explosion-proof exhaust ventilator with Ma protection level and explosion-proof motor IP68 protection level according to claim 2 is characterized in that: A front static seal and a rear static seal are respectively arranged between the front cover plate, the rear cover plate and the motor housing body, and a motor rotating shaft dynamic seal is arranged between the motor rotating shaft and the front cover plate.

4. The explosion-proof exhaust ventilator with Ma protection level and explosion-proof motor IP68 protection level according to claim 2 is characterized in that: The motor outlet pipe is connected to and passes through the motor housing body to communicate with the inner cavity of the flameproof motor, and an outlet pipe static seal is provided between the motor outlet pipe and the motor housing body.

5. The explosion-proof exhaust ventilator with Ma protection level and explosion-proof motor IP68 protection level according to claim 1 is characterized in that: The flameproof motor comprises a motor winding and a motor housing for accommodating the motor winding, the motor housing comprises a motor housing body and a rear end cover plate installed at an open end of the motor housing body, and the motor rotating shaft passes through the motor housing body toward an end away from the rear end cover plate to connect with an impeller.

6. The explosion-proof exhaust ventilator with Ma protection level and explosion-proof motor IP68 protection level according to claim 1 is characterized in that: The junction box comprises a junction box shell and a junction box cover plate buckled on the junction box shell, and the connection terminals are arranged at the bottom of the junction box shell, and the outer side of the bottom of the junction box shell is abutted and connected with the end face of the motor outlet pipe to seal the opening of the motor outlet pipe.

7. The explosion-proof exhaust ventilator with Ma protection level and explosion-proof motor IP68 protection level according to claim 6 is characterized in that: A junction box static seal is provided at the connection between the junction box shell and the motor outlet pipe to prevent gas from entering the motor sealing cavity from the connection between the junction box shell and the motor outlet pipe.

8. The explosion-proof exhaust ventilator with Ma protection level and explosion-proof motor IP68 protection level according to claim 6 is characterized by: A junction box cover plate static seal is provided between the junction box shell and the junction box cover plate.

9. The explosion-proof exhaust ventilator with Ma protection level and explosion-proof motor IP68 protection level according to claim 6, characterized in that: A terminal static seal is provided at the terminal to prevent gas from entering the motor sealing cavity from the terminal.

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