Arc extinguishing system of molded case circuit breaker

Abstract

The invention discloses a molded case circuit breaker arc extinguishing system, and belongs to the technical field of arc extinguishing systems, the molded case circuit breaker arc extinguishing system comprises an arc extinguishing housing, an arc extinguishing member, a gas recovery member and a drying member, the outer surface of the arc extinguishing housing is symmetrically provided with a plurality of first arc extinguishing grid sheets, and a plurality of second arc extinguishing grid sheets are fixedly connected between the first arc extinguishing grid sheets. And the arc extinguishing shell is located on the upper surface of the arc extinguishing grid piece I and is fixedly connected with a moving contact arc striking piece and a static contact arc striking piece respectively. According to the invention, the nitrogen and argon contained in the mixed gas have good insulation performance, the arc can be cooled and extinguished quickly, the arc extinguishing grid piece I and the arc extinguishing grid piece II can divide the arc into a plurality of small sections, and the arc extinguishing efficiency is improved. The length and the surface area of the electric arc are increased, cooling and extinguishing of the electric arc are accelerated, meanwhile, drying components contained in nitrogen and argon can reduce moisture on the surface of the arc extinguishing grid piece, rusting is prevented, and the drying agent in the drying ball makes contact with the mixed gas through the breathable film, so that the mixed gas is further dried.

Description

Technical Field

[0001] The present invention relates to the technical field of arc extinguishing systems, and more specifically, to an arc extinguishing system for a molded case circuit breaker. Background Art

[0002] Molded case circuit breaker (MCCB) is a common low-voltage electrical equipment. It consists of multiple key components, each of which has its specific function. They include operating handles, buttons, main contacts, tripping mechanisms, arc extinguishing systems and other components. Among them, the arc extinguishing system is particularly important because it is directly related to the safety and reliability of the circuit breaker when cutting off the current.

[0003] The existing arc extinguishing system is assembled from moving contacts, static contacts, arc extinguishing systems and other components. When the circuit breaker needs to be disconnected, the moving contacts and static contacts are electrically separated, and the arc will be guided into one or more arc extinguishing grids to divide the arc into many small segments, increasing the length and surface area of ​​the arc, thereby accelerating the cooling and energy dissipation of the arc. At the same time, the airflow in the arc extinguishing grids will also help take away heat, further accelerating the extinction of the arc.

[0004] In actual use, the existing arc extinguishing system has certain limitations. The arc is divided into multiple small segments by arc extinguishing grids, and the arc is accelerated to cool and extinguish by increasing the length and surface area of ​​the arc, resulting in lower arc extinguishing efficiency. In addition, the arc extinguishing grids are easily corroded by the arc and moisture during long-term use, causing rust on the surface, thereby affecting the arc extinguishing effect and service life.

[0005] Therefore, in view of the above technical problems, it is necessary to provide an arc extinguishing system for a molded case circuit breaker. Summary of the invention

[0006] The object of the present invention is to provide an arc extinguishing system for a molded case circuit breaker to solve the above-mentioned problems.

[0007] In order to achieve the above purpose, the technical solution provided by an embodiment of the present invention is as follows:

[0008] A molded case circuit breaker arc extinguishing system, comprising an arc extinguishing shell, an arc extinguishing component, a gas recovery component and a drying component, wherein a plurality of arc extinguishing grids 1 are symmetrically mounted on the outer surface of the arc extinguishing shell, a plurality of arc extinguishing grids 2 are fixedly connected between the arc extinguishing grids 1, and a moving contact arc ignition piece and a static contact arc ignition piece are respectively fixedly connected to the upper surface of the arc extinguishing grid 1 of the arc extinguishing shell; the arc extinguishing component is arranged on the outer surface of the arc extinguishing shell, and the arc extinguishing component divides the interior of the arc extinguishing shell into an arc extinguishing chamber and a storage chamber through a partition, a mixed gas tank is fixedly connected to the arc extinguishing chamber near the partition, and a gas outlet pipe is provided at one end of the mixed gas tank; the gas recovery component is arranged in the inner cavity of the arc extinguishing shell, and the gas recovery component comprises a connecting pipe arranged below the arc extinguishing shell, one end of the connecting pipe is connected to the interior of the mixed gas tank, and an electric valve is arranged on the outer surface of the connecting pipe;

[0009] The drying element is arranged in the inner cavity of the mixed gas tank, and the drying element comprises a plurality of drying balls arranged in the inner cavity of the mixed gas tank. The inner cavity of the drying balls is provided with a desiccant, and the outer surface of the desiccant is fixedly connected with a breathable film.

[0010] As a further improvement of the present invention, the inner wall of the outlet pipe is fixedly connected to a ring magnet, the side of the partition is hinged with a circular plate through a connecting plate, the outer surface of the circular plate is fixedly connected to a moving contact, and the side of the moving contact is fixedly connected to a circular magnet. When the moving contact is separated from the static contact, the magnetic connection between the circular magnet and the ring magnet will be broken due to the increase in gas pressure in the mixed gas tank, thereby accelerating the separation speed of the moving contact and the static contact. When the moving contact and the static contact are closed, the magnetic connection between the circular magnet and the ring magnet can ensure close contact between the moving contact and the static contact.

[0011] As a further improvement of the present invention, a sealing ring is fixedly connected to the outer surface of the circular magnet, and the outer surface of the sealing ring abuts against the inner wall of the annular magnet. The circular magnet is magnetically connected to the annular magnet. The sealing ring can ensure the sealing between the circular magnets to prevent gas leakage. At the same time, the magnetic connection between the circular magnets can ensure that the moving contact and the static contact are tightly connected under normal working conditions, reducing poor contact caused by vibration and other reasons.

[0012] As a further improvement of the present invention, a silicone pad is fixedly connected to the outer surface of the breathable film, and a plurality of breathable holes are provided on the outer surface of the silicone pad. Elastic ropes are fixedly connected between the desiccant balls. The breathable film is fixedly connected to the inner cavity of the desiccant balls, allowing gas to pass through but preventing desiccant particles from falling. At the same time, the plurality of breathable holes on the surface of the silicone pad can absorb moisture. The plurality of desiccant balls are connected by elastic ropes, which makes it convenient for staff to replace the desiccant balls.

[0013] As a further improvement of the present invention, a gas injection pipe is provided on the side of the mixed gas tank, and a sealing cover is movably connected to the outer surface of the gas injection pipe. The elastic rope is inserted into the outer surface of the sealing cover and is fixedly connected to a connecting block. The drying ball can be easily replaced through the connecting block, and mixed gases such as argon and nitrogen can be supplemented through the gas injection pipe.

[0014] As a further improvement of the present invention, a pressure sensor is provided inside the mixed gas tank for real-time monitoring of the pressure of the gas in the mixed gas tank to ensure that the gas pressure is sufficient and to guarantee the normal operation of the system.

[0015] As a further improvement of the present invention, a support plate is fixedly connected to the outer surface of the arc-extinguishing shell near the upper surface of the arc-extinguishing grid piece 2, and an arc plate is fixedly connected to the upper surface of the support plate. The arc plate can be supported by the support plate so as to lead the arc to the arc-extinguishing grid piece 2 and the arc-extinguishing grid piece 1.

[0016] As a further improvement of the present invention, a static contact is connected to the interior of the arc extinguishing housing near the static contact arc-starting piece, the outer surface of the static contact is abutted against a fixed block, a positioning groove is provided inside the fixed block, a clamping block is clamped inside the positioning groove, and the side of the clamping block is fixedly connected to the moving contact, ensuring that the connection between the moving contact and the static contact is more reliable and reduces wear.

[0017] As a further improvement of the present invention, a limiting groove is provided inside the fixed block near the positioning groove, a spring is fixedly connected to the inner wall of the limiting groove, a rubber clamp is fixedly connected to the other end of the spring, a movable groove is provided inside the clamp, and the rubber clamp is clamped with the movable groove, thereby ensuring that the moving contact and the static contact are firmly connected when closed and can be smoothly disengaged when separated, and the mutual cooperation between the spring and the rubber clamp ensures the reliability of the connection and the consistency of repeated actions.

[0018] As a further improvement of the present invention, the interior of the mixed gas tank is filled with a mixed gas of argon and nitrogen. Since the mixture of argon and nitrogen contains insulating properties and dryness, the insulating properties can quickly cool and extinguish the arc, and the dry components can reduce the moisture on the surface of the arc extinguishing grid piece one and the arc extinguishing grid piece two to prevent rust.

[0019] Compared with the prior art, the advantages of the present invention are:

[0020] (1) This solution uses the nitrogen and argon contained in the mixed gas to have good insulation properties and can quickly cool and extinguish the arc. The arc extinguishing grids 1 and 2 can divide the arc into multiple small segments, increasing the length and surface area of ​​the arc and accelerating its cooling and extinguishing. At the same time, the dry components contained in the nitrogen and argon can reduce the moisture on the surface of the arc extinguishing grid to prevent rust, thereby reducing arc erosion and rust and extending the service life of the arc extinguishing system.

[0021] (2) The desiccant inside the drying ball contacts the mixed gas through a breathable film, further drying the mixed gas and processing the small amount of moisture contained in the mixed gas, thereby improving the arc extinguishing effect. At the same time, the drying ball and silica gel pad keep the gas dry, reducing the erosion of the arc on the arc extinguishing grid. Since the nitrogen and argon mixed gas has good insulation properties, it can improve the arc extinguishing effect while reducing damage to the arc extinguishing grid.

[0022] (3) The coordination of the clamp, positioning groove, spring, rubber clamp and limit groove ensures that the moving contact and the static contact are firmly connected and wear is reduced. At the same time, the magnetic connection between the circular magnet and the annular magnet ensures that the separation and contact process between the moving contact and the static contact is smooth and reliable. The sealing ring between the circular magnet and the annular magnet ensures the sealing of the mixed gas tank to prevent external moisture from entering.

[0023] (4) The mixed gas released from the arc extinguishing chamber can be pumped into the mixed gas tank through the electric valve and the connecting pipe so that the gas can be recycled. At the same time, the drying ball can be replaced regularly through the cooperation of the elastic rope and the gas injection pipe. The pressure sensor monitors the pressure in the mixed gas tank in real time to ensure the safety of gas storage. If the argon and nitrogen content in the mixed gas tank is insufficient, it can be injected through the gas injection pipe to ensure that the argon and nitrogen content in the mixed gas tank is always sufficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The overall structural diagram of the present invention;

[0025] Figure 2 This is a schematic diagram of the opening structure of the movable contact of the present invention;

[0026] Figure 3 For the present invention Figure 2 A magnified view of the structure at center A;

[0027] Figure 4 It is a partial structural breakdown diagram of the whole invention;

[0028] Figure 5 For the present invention Figure 4 A magnified view of the structure at B in the middle;

[0029] Figure 6 This is a partial structural breakdown diagram of the gas recovery component and the drying component of the present invention.

[0030] Description of the numbers in the figure:

[0031] 1. Arc extinguishing housing; 101. Arc extinguishing grid piece 1; 102. Arc extinguishing grid piece 2; 104. Moving contact arc ignition piece; 105. Static contact arc ignition piece;

[0032] 2. Arc extinguishing member; 201. Partition plate; 202. Arc extinguishing chamber; 203. Storage chamber; 204. Mixed gas tank; 205. Gas outlet pipe; 206. Ring magnet;

[0033] 3. Round plate; 4. Moving contact; 5. Round magnet; 6. Sealing ring;

[0034] 7. Gas recovery parts; 701. Connecting pipe; 702. Electric valve;

[0035] 8. Drying element; 801. Drying ball; 802. Desiccant; 803. Breathable film; 804. Silicone pad; 805. Breathable hole; 806. Elastic rope; 807. Air injection tube; 808. Pressure sensor;

[0036] 9. Support plate; 10. Arc plate; 11. Static contact; 12. Fixed block; 13. Positioning slot; 14. Card block; 15. Limiting slot; 16. Spring; 17. Rubber card block; 18. Moving slot. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0038] Embodiment 1:

[0039] See also Figure 1-6 A molded case circuit breaker arc extinguishing system comprises an arc extinguishing housing 1, an arc extinguishing component 2, a gas recovery component 7 and a drying component 8. A plurality of arc extinguishing grids 101 are symmetrically mounted on the outer surface of the arc extinguishing housing 1, a plurality of arc extinguishing grids 102 are fixedly connected between the arc extinguishing grids 101, and a moving contact arc ignition piece 104 and a static contact arc ignition piece 105 are fixedly connected to the upper surface of the arc extinguishing housing 1 located on the arc extinguishing grids 101.

[0040] Specifically, the arc extinguishing component 2 is arranged on the outer surface of the arc extinguishing shell 1, and the arc extinguishing component 2 divides the interior of the arc extinguishing shell 1 into an arc extinguishing chamber 202 and a storage chamber 203 through a partition 201. The arc extinguishing chamber 202 is fixedly connected with a mixed gas tank 204 near the partition 201, and an outlet pipe 205 is opened at one end of the mixed gas tank 204. The gas recovery component 7 is arranged in the inner cavity of the arc extinguishing shell 1, and the gas recovery component 7 includes a connecting pipe 701 arranged below the arc extinguishing shell 1, one end of the connecting pipe 701 is connected to the interior of the mixed gas tank 204, and an electric valve 702 is arranged on the outer surface of the connecting pipe 701. The electric valve 702 is a valve that is opened and closed by an electric signal. In the arc extinguishing system of the molded case circuit breaker, the electric valve 702 is used to control the flow of gas.

[0041] The inner wall of the air outlet pipe 205 is fixedly connected with an annular magnet 206, and the side of the partition 201 is hinged with a circular plate 3 through a connecting plate. The outer surface of the circular plate 3 is fixedly connected with a moving contact 4, and the side of the moving contact 4 is fixedly connected with a circular magnet 5. The outer surface of the circular magnet 5 is fixedly connected with a sealing ring 6, and the outer surface of the sealing ring 6 abuts against the inner wall of the annular magnet 206. The circular magnet 5 is magnetically connected to the annular magnet 206. The interior of the arc extinguishing shell 1 is connected with a static contact 11 near the static contact arc-starting piece 105. The static contact 11 is a fixed contact in the circuit breaker, and is usually used in combination with the moving contact 4 to jointly complete the circuit closing and disconnecting functions. In the molded case circuit breaker, the static contact 11 is usually a fixed part, and the moving contact 4 is a movable part. The two contact or separate with each other during the operation of the circuit breaker to control the on and off of the current.

[0042] The outer surface of the static contact 11 is abutted with a fixed block 12, a positioning groove 13 is provided inside the fixed block 12, a block 14 is clamped inside the positioning groove 13, and the side of the block 14 is fixedly connected to the moving contact 4. A limiting groove 15 is provided inside the fixed block 12 near the positioning groove 13, a spring 16 is fixedly connected to the inner wall of the limiting groove 15, and a rubber block 17 is fixedly connected to the other end of the spring 16. A moving groove 18 is provided inside the block 14, and the rubber block 17 is clamped with the moving groove 18. The interior of the mixed gas tank 204 is filled with a mixed gas of argon and nitrogen. Argon and nitrogen are both colorless, odorless, and non-flammable inert gases. The mixed gas of argon and nitrogen has good insulating properties, which can effectively isolate current and prevent the formation and development of arcs. At the same time, the mixed gas of argon and nitrogen can also quickly absorb the heat generated by the arc and accelerate the extinction of the arc. Due to the high heat capacity of the two gases, they can effectively take away heat and reduce the arc temperature.

[0043] Furthermore, when the circuit breaker detects an overload or short circuit, the moving contact 4 and the static contact 11 are electrically separated to cause the moving contact 4 to move through the circular plate 3. When the moving contact 4 continues to move, it will drive the block 14 to separate from the positioning groove 13, and further discharge the argon and nitrogen mixed gas in the mixed gas tank 204 from the outlet pipe 205 and enter the arc extinguishing chamber 202. The arc generated in the arc extinguishing chamber 202 will contact the argon and nitrogen mixed gas, and the arc will be divided into multiple small segments by the arc extinguishing grid piece 101 and the arc extinguishing grid piece 2 102. The divided arc is extinguished by the mixed gas. Arc extinguishing accelerates the cooling and extinguishing of the arc. At the same time, the dry components contained in the mixed gas can dry the arc extinguishing grid 101 and the arc extinguishing grid 2 102. When the arc extinguishing work is completed, the moving contact 4 contacts the static contact 11 again through the circular plate 3, and the block 14 on the surface of the moving contact 4 can be engaged with the positioning groove 13 to ensure that the static contact 11 and the moving contact 4 are firmly connected. At the same time, the circular magnet 5 on the moving contact 4 will be magnetically connected to the annular magnet 206 in the mixed gas tank 204, and the sealing sleeve 6 on the surface of the circular magnet 5 ensures that the mixed gas tank 204 is sealed.

[0044] Embodiment 2:

[0045] Reference Figure 1-Figure 6 , which is the second embodiment of the present invention. This embodiment is based on the previous embodiment, and the drying element 8 is arranged in the inner cavity of the mixed gas tank 204.

[0046] Specifically, the drying element 8 includes a plurality of drying balls 801 arranged in the inner cavity of the mixed gas tank 204. The inner cavity of the drying ball 801 is provided with a desiccant 802. The desiccant 802 refers to a type of substance that can absorb moisture in the surrounding environment and keep the substance dry. It absorbs moisture through physical adsorption or chemical reaction, so that the desiccant 802 can absorb moisture in the mixed gas and keep the gas in a dry state. The outer surface of the desiccant 802 is fixedly connected with a breathable film 803. The breathable film 803 can be replaced by materials such as polytetrafluoroethylene, polyester, and polyurethane. It allows gas to pass through but can prevent solid particles or liquids from dripping in. In the arc extinguishing system of the molded case circuit breaker, the breathable film 803 is mainly used to ensure that the gas can pass freely, while preventing the desiccant 802 particles or other impurities from entering the mixed gas tank 204 or the arc extinguishing chamber 202.

[0047] The outer surface of the breathable film 803 is fixedly connected to a silicone pad 804, and the outer surface of the silicone pad 804 is provided with a plurality of breathable holes 805, and elastic ropes 806 are fixedly connected between the drying balls 801, and a gas injection pipe 807 is provided on the side of the mixed gas tank 204, and the outer surface of the gas injection pipe 807 is movably connected to a sealing cover, and the elastic rope 806 is inserted into the outer surface of the sealing cover and fixedly connected to a connecting block, and a pressure sensor 808 is arranged inside the mixed gas tank 204, and the outer surface of the arc extinguishing housing 1 is fixedly connected to a support plate 9 near the upper surface of the arc extinguishing grid 2 102, and the upper surface of the support plate 9 is fixedly connected to an arc plate 10.

[0048] Furthermore, the electric valve 702 is started to pump the mixed gas in the arc extinguishing chamber 202 into the mixed gas tank 204 through the connecting pipe 701, so that the desiccant 802 inside the multiple drying balls 801 can contact the mixed gas through the breathable film 803, and the moisture contained in the mixed gas can enter the drying balls 801 through the breathable holes 805 for adsorption, thereby keeping the gas dry, and the argon and nitrogen content in the mixed gas tank 204 can be monitored in real time through the pressure sensor 808. If the argon and nitrogen content is insufficient, the argon and nitrogen mixed gas can be injected into the interior through the gas injection pipe 807 to ensure that the argon and nitrogen content in the mixed gas tank 204 is always sufficient.

[0049] The working principle of the present invention is as follows: when the circuit breaker detects an overload or a short circuit, the moving contact 4 and the static contact 11 are electrically separated to cause the moving contact 4 to move through the circular plate 3. When the moving contact 4 moves, the circular magnet 5 is driven to move. The movement of the circular magnet 5 increases the pressure of the saturated argon and nitrogen in the mixed gas tank 204. The increased pressure causes the circular magnet 5 to separate from the annular magnet 206 in the gas outlet pipe 205, accelerating the movement of the moving contact 4. When the moving contact 4 continues to move, the block 14 is driven to separate from the positioning groove 13, further The mixed gas of argon and nitrogen in the mixed gas tank 204 is discharged from the gas outlet pipe 205 and enters the arc extinguishing chamber 202, and the arc generated in the arc extinguishing chamber 202 will come into contact with the mixed gas of argon and nitrogen, and the arc is divided into multiple small segments by the arc extinguishing grid 101 and the arc extinguishing grid 2 102, and the divided arc is extinguished by the mixed gas to accelerate the cooling and extinction of the arc. At the same time, the dry components contained in the mixed gas can dry the arc extinguishing grid 101 and the arc extinguishing grid 2 102 to reduce the erosion caused by the arc and prevent rust.

[0050] After the arc extinguishing work is completed, the moving contact 4 contacts the static contact 11 again through the circular plate 3, and the block 14 on the surface of the moving contact 4 can be engaged with the positioning groove 13. When the block 14 enters the positioning groove 13, it will touch the rubber block 17, and the rubber block 17 drives the spring 16 to enter the limit groove 15 for compression. When the block 14 is fully engaged with the positioning groove 13, the elasticity of the spring 16 drives the rubber block 17 to engage with the moving groove 18 in the block 14, ensuring that the static contact 11 is firmly connected to the moving contact 4. At the same time, the circular magnet 5 on the moving contact 4 will be magnetically connected to the annular magnet 206 in the mixed gas tank 204, and the sealing sleeve 6 on the surface of the circular magnet 5 ensures that the mixed gas tank 204 is sealed.

[0051] Subsequently, the electric valve 702 is started to pump the mixed gas in the arc extinguishing chamber 202 into the mixed gas tank 204 through the connecting pipe 701, so that the desiccant 802 inside the multiple drying balls 801 can contact the mixed gas through the breathable film 803, and the moisture contained in the mixed gas can enter the drying ball 801 through the breathable holes 805 for adsorption, thereby keeping the gas dry, and the argon and nitrogen content in the mixed gas tank 204 can be monitored in real time through the pressure sensor 808. If the argon and nitrogen content is insufficient, the argon and nitrogen mixed gas can be injected into the interior through the gas injection pipe 807 to ensure that the argon and nitrogen content in the mixed gas tank 204 is always sufficient. After the dry ball 801 has been used for a period of time, the dry ball 802 is removed through the gas injection pipe 807 for replacement.

[0052] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0053] In addition, it should be understood that although the present specification is described according to embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that those skilled in the art can understand.

Claims

1. A molded case circuit breaker arc extinguishing system, characterized in that: include: An arc-extinguishing housing (1), wherein a plurality of arc-extinguishing grid pieces (101) are symmetrically mounted on the outer surface of the arc-extinguishing housing (1), a plurality of arc-extinguishing grid pieces (102) are fixedly connected between the arc-extinguishing grid pieces (101), and a movable contact arc-striking piece (104) and a stationary contact arc-striking piece (105) are respectively fixedly connected on the upper surface of the arc-extinguishing grid pieces (101) of the arc-extinguishing housing (1); An arc extinguishing member (2) is arranged on the outer surface of the arc extinguishing housing (1), the arc extinguishing member (2) divides the interior of the arc extinguishing housing (1) into an arc extinguishing chamber (202) and a storage chamber (203) through a partition (201), a mixed gas tank (204) is fixedly connected to the arc extinguishing chamber (202) near the partition (201), and an outlet pipe (205) is provided at one end of the mixed gas tank (204); A gas recovery component (7) is arranged in the inner cavity of the arc extinguishing housing (1), the gas recovery component (7) comprising a connecting pipe (701) arranged below the arc extinguishing housing (1), one end of the connecting pipe (701) is connected to the interior of the mixed gas tank (204), and an electric valve (702) is arranged on the outer surface of the connecting pipe (701); A drying element (8) is arranged in the inner cavity of the mixed gas tank (204), and the drying element (8) comprises a plurality of drying balls (801) arranged in the inner cavity of the mixed gas tank (204). A desiccant (802) is arranged in the inner cavity of the drying balls (801), and a breathable film (803) is fixedly connected to the outer surface of the desiccant (802).

2. The arc extinguishing system for a molded case circuit breaker according to claim 1, characterized in that: The inner wall of the air outlet pipe (205) is fixedly connected to a ring magnet (206); the side of the partition (201) is hinged with a circular plate (3) via a connecting plate; the outer surface of the circular plate (3) is fixedly connected to a moving contact (4); and the side of the moving contact (4) is fixedly connected to a circular magnet (5).

3. The arc extinguishing system for a molded case circuit breaker according to claim 2, characterized in that: A sealing ring (6) is fixedly connected to the outer surface of the circular magnet (5), the outer surface of the sealing ring (6) abuts against the inner wall of the annular magnet (206), and the circular magnet (5) is magnetically connected to the annular magnet (206).

4. The arc extinguishing system for a molded case circuit breaker according to claim 1, characterized in that: A silica gel pad (804) is fixedly connected to the outer surface of the breathable film (803), and a plurality of breathable holes (805) are provided on the outer surface of the silica gel pad (804). Elastic ropes (806) are fixedly connected between the drying balls (801).

5. The arc extinguishing system for a molded case circuit breaker according to claim 4, characterized in that: An air injection pipe (807) is provided on the side of the mixed gas tank (204), and a sealing cover is movably connected to the outer surface of the air injection pipe (807). The elastic rope (806) is inserted into the outer surface of the sealing cover and fixedly connected to a connecting block.

6. The arc extinguishing system for a molded case circuit breaker according to claim 1, characterized in that: A pressure sensor (808) is disposed inside the mixed gas tank (204).

7. The arc extinguishing system for a molded case circuit breaker according to claim 1, characterized in that: A support plate (9) is fixedly connected to the outer surface of the arc-extinguishing housing (1) close to the upper surface of the second arc-extinguishing grid (102), and an arc-shaped plate (10) is fixedly connected to the upper surface of the support plate (9).

8. The arc extinguishing system for a molded case circuit breaker according to claim 2, characterized in that: A static contact (11) is connected to the interior of the arc-extinguishing housing (1) near the static contact arc-starting piece (105); a fixed block (12) is abutted against the outer surface of the static contact (11); a positioning groove (13) is provided inside the fixed block (12); a clamping block (14) is clamped inside the positioning groove (13); and a side surface of the clamping block (14) is fixedly connected to the moving contact (4).

9. The arc extinguishing system for a molded case circuit breaker according to claim 8, characterized in that: The fixed block (12) is provided with a limiting groove (15) near the positioning groove (13); the inner wall of the limiting groove (15) is fixedly connected to a spring (16); the other end of the spring (16) is fixedly connected to a rubber clamping block (17); a movable groove (18) is provided inside the clamping block (14); and the rubber clamping block (17) is clamped with the movable groove (18).

10. The arc extinguishing system for a molded case circuit breaker according to claim 1, characterized in that: The interior of the mixed gas tank (204) is filled with a mixed gas of argon and nitrogen.

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