Mining flame-proof and intrinsically safe frequency conversion speed regulation control box

Abstract

The utility model relates to the technical field of mining electrical equipment, and particularly discloses a mining flame-proof and intrinsically safe frequency conversion speed regulation control box, which comprises a control box provided with a box door, the interior of the control box is divided into a flame-proof cavity and an intrinsically safe cavity which are distributed up and down through a metal partition plate, and the top end of the control box is provided with a heat dissipation cavity. The heat dissipation cavity and the explosion-proof cavity are physically isolated through a heat conduction metal wall, strong and weak electricity physical isolation can be achieved through the explosion-proof cavity and the intrinsic safety cavity which are distributed up and down, energy crosstalk is avoided, the cavity distribution is optimized, and meanwhile regional operation of maintenance personnel is facilitated. The stepped concave-convex structure is matched with the double-layer sealing structure, explosion flames and pressure can be limited in the cavity, the explosion flames and high-temperature gas in the explosion-proof cavity are prevented from leaking out, the external environment is prevented from being ignited, the explosion-proof reliability is achieved, compared with traditional plane sealing, the stepped concave-convex structure can increase the complexity of a flame propagation path, and the explosion-proof performance is improved. The vibration deformation resistance is improved, and the sealing performance can still be kept after long-term use.

Description

Technical Field

[0001] This utility model relates to the field of mining electrical equipment technology, and specifically discloses a mining explosion-proof and intrinsically safe variable frequency speed control box. Background Technology

[0002] The explosion-proof and intrinsically safe variable frequency speed control box for mining (hereinafter referred to as the control box) is suitable for environments in coal mines and surrounding media containing explosive mixtures of gases such as methane and coal dust. In AC 50Hz circuits with rated voltage up to 660V and rated total current up to 90A, the control box can be used as a speed control device and starting switch for various equipment in mining areas and other working faces. When equipment experiences overload, short circuit, overvoltage, undervoltage, or other faults, it can automatically cut off the power supply and display fault signals. The control box has a leakage current interlock function before closing the circuit and can display the current and voltage values ​​of each branch during operation. It has protection against undervoltage, overload, phase loss, short circuit, and leakage current interlock.

[0003] Traditional explosion-proof and intrinsically safe variable frequency speed control boxes for mining use have explosion-proof circuits and intrinsically safe circuits housed in the same cavity, separated only by a simple isolation plate. This can easily lead to energy crosstalk, causing malfunctions of intrinsically safe signals. The door and cavity mating surface uses a planar seal, which is prone to failure due to long-term vibration. The inlet and outlet ports often use a single-layer rubber seal, which can easily leak flames during explosion tests. Therefore, a new explosion-proof and intrinsically safe variable frequency speed control box for mining is needed to solve this problem. Utility Model Content

[0004] This utility model proposes a mine-use explosion-proof and intrinsically safe variable frequency speed control box. Through the vertically distributed explosion-proof cavity and intrinsically safe cavity, strong and weak electrical physical isolation can be achieved to avoid energy crosstalk. The cavity layout is optimized. The stepped concave-convex structure combined with the double-layer sealing structure can limit the explosion flame and pressure inside the cavity, prevent the explosion flame and high-temperature gas inside the explosion-proof cavity from leaking out, and achieve explosion-proof reliability.

[0005] This utility model is implemented as follows: a mine-use explosion-proof and intrinsically safe variable frequency speed control box includes a control box with a door. The interior of the control box is divided by a metal partition to form an explosion-proof cavity and an intrinsically safe cavity distributed vertically. The explosion-proof cavity is located in the upper part and houses the frequency converter and power module. The intrinsically safe cavity is located in the lower part and independently houses the intrinsically safe control circuit, which is electrically isolated from the explosion-proof cavity through a through-wall terminal. A heat dissipation cavity is provided at the top of the control box, and the heat dissipation cavity is physically isolated from the explosion-proof cavity by a thermally conductive metal wall.

[0006] The upper surface of the explosion-proof cavity is provided with heat dissipation fins, which penetrate the heat-conducting metal wall and extend into the interior of the heat dissipation cavity. An air duct is installed at the top of the interior of the heat dissipation cavity, and an air hole is opened through the bottom of the air duct. The air hole is directly opposite the surface of the heat dissipation fins. A fan is installed on the outer wall of the heat dissipation cavity. The air inlet of the fan is connected to the outside, and the air outlet is connected to the air duct.

[0007] A door panel is provided on the front side of the explosion-proof cavity, and the contact surface between the door panel and the opening of the explosion-proof cavity has a stepped concave-convex structure.

[0008] Both the explosion-proof cavity and the intrinsically safe cavity have inlet and outlet ports on their side walls. The inlet and outlet ports are close to the terminal blocks inside the corresponding cavities and adopt a double-layer sealing structure, including: an outer layer seal, in which an oil-resistant rubber sealing ring is embedded inside the metal threaded clamping nut; and an inner layer seal, in which an annular cavity is located inside the rubber sealing ring and is filled with mining explosion-proof mortar.

[0009] As a preferred embodiment of the explosion-proof and intrinsically safe variable frequency speed control box for mining according to this utility model, thermally conductive silicone is coated between the inner wall of the top of the explosion-proof cavity and the heat dissipation fins.

[0010] As a preferred embodiment of the explosion-proof and intrinsically safe variable frequency speed control box for mining applications according to this utility model, the control box is made of thickened steel plate welded together.

[0011] As a preferred embodiment of the explosion-proof and intrinsically safe variable frequency speed control box for mining according to this utility model, an air outlet with an inclined downward orientation is provided on the right side of the outer wall of the heat dissipation cavity, and a dust filter is embedded in the air outlet.

[0012] As a preferred embodiment of the explosion-proof and intrinsically safe variable frequency speed control box for mining applications according to this utility model, the heat dissipation fins are corrugated aluminum fins.

[0013] As a preferred embodiment of the explosion-proof and intrinsically safe variable frequency speed control box for mining according to this utility model, the through-wall terminal is made of ceramic insulating material, and both ends are fixed to the metal partition by epoxy resin potting.

[0014] The beneficial effects of this utility model are:

[0015] 1. The explosion-proof and intrinsically safe chambers distributed vertically can achieve physical isolation between strong and weak currents, avoid energy crosstalk, optimize the chamber layout, and facilitate maintenance personnel to operate in different areas.

[0016] 2. By operating the fan, outside air is drawn into the air duct and directly washes the heat dissipation fins through the air holes, thereby improving heat dissipation efficiency;

[0017] 3. The stepped concave-convex structure combined with the double-layer sealing structure can confine the explosion flame and pressure within the cavity, preventing the explosion flame and high-temperature gas inside the explosion-proof cavity from leaking out, preventing the ignition of the external environment, and achieving explosion-proof reliability. Compared with traditional flat seals, the stepped concave-convex structure can increase the complexity of the flame propagation path, improve the resistance to vibration and deformation, and maintain the sealing performance even after long-term use. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0019] Figure 1 This is an overall structural diagram of a mine explosion-proof and intrinsically safe variable frequency speed control box according to the present invention.

[0020] Figure 2 This is a front sectional view of a mine explosion-proof and intrinsically safe variable frequency speed control box according to the present invention.

[0021] Figure 3 This is a front view structural diagram of a mine explosion-proof and intrinsically safe variable frequency speed control box according to the present invention.

[0022] Figure 4 This is a side view of the door panel structure of this utility model.

[0023] Figure 5 This utility model Figure 2 Enlarged structural diagram at point A.

[0024] The markings in the diagram are: 1. Control box; 101. Metal partition; 2. Explosion-proof cavity; 201. Thermally conductive silicone; 202. Heat dissipation fins; 203. Door panel; 3. Intrinsically safe cavity; 4. Heat dissipation cavity; 401. Air duct; 402. Fan; 403. Air vent; 404. Air outlet; 5. Cable inlet / outlet; 501. Rubber sealing ring; 502. Annular cavity. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments to aid in understanding its content. Unless otherwise specified, the methods used in this invention are conventional methods; the raw materials and apparatus used, unless otherwise specified, are conventional commercially available products.

[0026] Please see Figure 1-5A mine-use explosion-proof and intrinsically safe variable frequency speed control box includes a control box 1 with a door. The interior of the control box 1 is divided by a metal partition 101 to form an explosion-proof cavity 2 and an intrinsically safe cavity 3 distributed vertically. The explosion-proof cavity 2 is located in the upper part and houses a frequency converter and a power module. The intrinsically safe cavity 3 is located in the lower part and independently houses an intrinsically safe control circuit. It is electrically isolated from the explosion-proof cavity 2 through a wall terminal. A heat dissipation cavity 4 is provided at the top of the control box 1. The heat dissipation cavity 4 is physically isolated from the explosion-proof cavity 2 by a thermally conductive metal wall.

[0027] The upper end face of the explosion-proof cavity 2 is provided with heat dissipation fins 202, which penetrate the heat-conducting metal wall and extend into the interior of the heat dissipation cavity 4. The top of the interior of the heat dissipation cavity 4 is equipped with an air duct 401, and the bottom end of the air duct 401 is provided with an air hole 403, which is directly opposite the surface of the heat dissipation fins 202. The outer wall of the heat dissipation cavity 4 is equipped with a fan 402, the air inlet of the fan 402 is connected to the outside, and the outlet is connected to the air duct 401.

[0028] A door panel 203 is provided on the front side inside the explosion-proof cavity 2. The contact surface between the door panel 203 and the opening of the explosion-proof cavity 2 is a stepped concave-convex structure.

[0029] Both the explosion-proof cavity 2 and the intrinsically safe cavity 3 have inlet / outlet ports 5 on their side walls. The inlet / outlet ports 5 are close to the terminal blocks inside the corresponding cavities and adopt a double-layer sealing structure, including: an outer layer seal, in which an oil-resistant rubber sealing ring 501 is embedded inside the metal threaded clamping nut; and an inner layer seal, in which an annular cavity 502 is formed inside the rubber sealing ring 501 and the interior of the annular cavity 502 is filled with mine explosion-proof mortar.

[0030] In this embodiment: the explosion-proof cavity 2 and intrinsically safe cavity 3 distributed vertically can achieve physical isolation between strong and weak currents, avoid energy crosstalk, optimize the cavity layout, and facilitate maintenance personnel to operate in different areas.

[0031] By operating the fan 402, external air enters the air duct 401 and directly washes the heat dissipation fins 202 through the air holes 403, thereby improving the heat dissipation efficiency.

[0032] The precision-machined stepped concave-convex structure can confine the explosion flame and pressure within the cavity, preventing ignition of the external environment. Compared with traditional flat seals, the stepped concave-convex structure can increase the complexity of the flame propagation path, improve the resistance to vibration and deformation, and maintain the sealing performance even after long-term use.

[0033] By employing a double-layer sealing structure within the inlet / outlet port 5, the leakage of explosion flames and high-temperature gases from the explosion-proof chamber 2 can be prevented, and dust and moisture from the intrinsically safe chamber 3 can be prevented from entering the enclosure through cable gaps, thus achieving reliable explosion-proof protection.

[0034] As a technical optimization of this utility model, thermally conductive silicone 201 is coated between the top inner wall of the explosion-proof cavity 2 and the heat dissipation fins 202.

[0035] In this embodiment: thermally conductive silicone 201 can fill the microscopic gaps between the metal wall and the heat dissipation fins 202, and after curing, it forms a continuous thermally conductive interface, improving heat conduction efficiency and avoiding local overheating.

[0036] As a technical optimization of this utility model, the control box 1 is made of thickened steel plate welded together.

[0037] In this embodiment, by using thickened steel plates for welding the control box 1, the structural strength of the box 1 can be increased and the explosion resistance can be improved.

[0038] As a technical optimization of this utility model, an air outlet 404 with an inclined downward orientation is provided on the right side of the outer wall of the heat dissipation cavity 4, and a dust filter is embedded in the air outlet 404.

[0039] In this embodiment, the problems of dust accumulation and water backflow can be solved by using the downward-facing air outlet 404 and the dust filter.

[0040] As a technical optimization of this utility model, the heat dissipation fin 202 is a wavy aluminum fin.

[0041] In this embodiment, the heat dissipation efficiency can be improved by using wavy aluminum fins for the heat dissipation fins 202.

[0042] As a technical optimization of this utility model, the through-wall terminal is made of ceramic insulating material, and both ends are fixed to the metal partition 101 by epoxy resin potting.

[0043] In this embodiment, by using ceramic insulating material for the through-wall terminals and fixing both ends to the metal partition 101 with epoxy resin potting, the energy isolation between the intrinsically safe circuit and the explosion-proof cavity 2 can be ensured.

[0044] The working principle and usage process of this utility model: the explosion-proof cavity 2 is used to install high-power, heat-generating components (such as frequency converters and power modules), and the intrinsically safe cavity 3 is used to independently install intrinsically safe control circuits (such as PLCs and signal interfaces). Through the vertically distributed explosion-proof cavity 2 and intrinsically safe cavity 3, strong and weak electrical physical isolation can be achieved, energy crosstalk can be avoided, the cavity layout can be optimized, and maintenance personnel can operate in different areas.

[0045] By operating the fan 402, external air enters the air duct 401 and directly washes the heat dissipation fins 202 through the air holes 403, thereby improving the heat dissipation efficiency.

[0046] When an explosion occurs in the explosion-proof chamber 2, the explosion flame and pressure are confined within the chamber by the precision-machined stepped concave-convex structure, and the leaking gas is cooled to prevent ignition of the external environment. Compared with traditional flat seals, the stepped concave-convex structure can increase the complexity of the flame propagation path, improve the resistance to vibration and deformation, and maintain the sealing performance after long-term use.

[0047] An oil-resistant rubber sealing ring 501 is embedded inside the metal threaded clamping nut at the inlet / outlet port 5. By tightening the clamping nut, the rubber sealing ring 501 deforms and fills the gap between the cable and the inlet / outlet port 5, achieving initial waterproofing and dustproofing. After the explosion-proof putty cures, it forms a dense barrier, further preventing the leakage of explosion flames and high-temperature gases in the explosion-proof chamber 2, and preventing dust and moisture in the intrinsically safe chamber 3 from entering the interior of the enclosure through the cable gaps, thus achieving reliable explosion-proof protection.

[0048] In the description of this utility model, it should be understood that the terms "left", "right", "up", "down", "top", "bottom", "front", "back", "inner", "outer", "back", "middle", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0049] However, the above description is only a specific embodiment of this utility model and should not be construed as limiting the scope of implementation of this utility model. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of this utility model should still fall within the scope of the claims of this utility model.

Claims

1. A mine-use explosion-proof and intrinsically safe variable frequency speed control box, comprising a control box (1) with a door, characterized in that: The control box (1) is divided into an explosion-proof cavity (2) and an intrinsically safe cavity (3) by a metal partition (101). The explosion-proof cavity (2) is located at the top and contains a frequency converter and a power module. The intrinsically safe cavity (3) is located at the bottom and has an independently installed intrinsically safe control circuit. It is electrically isolated from the explosion-proof cavity (2) by a through-wall terminal. The top of the control box (1) is provided with a heat dissipation cavity (4). The heat dissipation cavity (4) and the explosion-proof cavity (2) are physically isolated by a thermally conductive metal wall. The upper end face of the explosion-proof cavity (2) is provided with heat dissipation fins (202). The heat dissipation fins (202) penetrate through the heat-conducting metal wall and extend into the interior of the heat dissipation cavity (4). The top of the interior of the heat dissipation cavity (4) is equipped with an air duct (401). The bottom end of the air duct (401) is provided with an air hole (403). The air hole (403) is directly opposite the surface of the heat dissipation fins (202). The outer wall of the heat dissipation cavity (4) is equipped with a fan (402). The air inlet of the fan (402) is connected to the outside, and the outlet is connected to the air duct (401). A door panel (203) is provided on the front side inside the explosion-proof cavity (2), and the contact surface between the door panel (203) and the opening of the explosion-proof cavity (2) is a stepped concave-convex structure. Both the explosion-proof cavity (2) and the intrinsically safe cavity (3) have inlet and outlet ports (5) on their side walls. The inlet and outlet ports (5) are close to the terminal blocks in the corresponding cavities and adopt a double-layer sealing structure, including: an outer layer seal, in which an oil-resistant rubber sealing ring (501) is embedded in the inner side of a metal threaded clamping nut; and an inner layer seal, in which an annular cavity (502) is formed inside the rubber sealing ring (501), and the interior of the annular cavity (502) is filled with mine explosion-proof mortar.

2. The explosion-proof and intrinsically safe variable frequency speed control box for mining as described in claim 1, characterized in that: Thermally conductive silicone (201) is coated between the top inner wall of the explosion-proof cavity (2) and the heat dissipation fins (202).

3. The explosion-proof and intrinsically safe variable frequency speed control box for mining as described in claim 1, characterized in that: The control box (1) is made of thickened steel plate welded together.

4. A mine-use explosion-proof and intrinsically safe variable frequency speed control box according to claim 1, characterized in that: An air outlet (404) is provided on the right side of the outer wall of the heat dissipation cavity (4) and is inclined downward. A dust filter is embedded in the air outlet (404).

5. A mine-use explosion-proof and intrinsically safe variable frequency speed control box according to claim 1, characterized in that: The heat dissipation fins (202) are wavy aluminum fins.

6. A mine-use explosion-proof and intrinsically safe variable frequency speed control box according to claim 1, characterized in that: The through-wall terminal is made of ceramic insulation material, and both ends are fixed to the metal partition (101) by epoxy resin potting.

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