An explosion-proof device with a built-in integrated breathing unit in a closed cavity and a preparation method thereof

Abstract

The application relates to a closed cavity explosion-proof device with an embedded integrated breathing unit and a preparation method thereof. A double-gas-path decoupling structure with a hollow guide rod embedded with a breathing unit is adopted. A central micro-breathing branch is connected with an anti-adhesion flexible moisture-proof valve plate and a moisture absorption column from top to bottom. An independent annular main pressure relief branch is arranged in the periphery. A heavy ion microporous membrane is matched in the outer layer as a waterproof and breathable barrier. The moisture-proof valve plate adopts a central anti-adhesion micropore and a notch root annular thinning groove structure. The moisture absorption column adopts 4A molecular sieve and epoxy resin pre-mixed integrated molding, and pure potassium carbonate is used as a pore forming agent. The application can improve problems such as valve plate high-temperature self-adhesion, moisture absorption component powder falling and membrane blockage, and gas path coupling interference, and improve pressure relief precision and long-acting moisture-proof performance. The application can be widely matched with various closed electrical equipment such as power battery packs, energy storage boxes, communication cabinets and the like.

Description

Technical Field

[0001] This application relates to the field of safety protection and pressure regulation technology for sealed electrical equipment, and in particular to an explosion-proof device for a sealed cavity with a built-in integrated breathing unit and its preparation method. Background Technology

[0002] With the implementation of updated safety standards for power batteries and the rapid development of energy storage systems and outdoor communication equipment, the operating conditions of various sealed electrical cavities are becoming increasingly complex, placing higher demands on explosion-proof pressure relief accuracy, long-term anti-condensation capability, and full life-cycle reliability. As a core safety protection component of sealed cavities, explosion-proof pressure regulating devices perform multiple functions, including maintaining daily temperature balance, providing explosion-proof pressure relief under extreme conditions, and preventing the intrusion of external moisture and dust. Their performance directly affects the operational safety and service life of sealed electrical equipment.

[0003] Currently, mainstream explosion-proof pressure regulating devices in the industry generally use expanded polytetrafluoroethylene (ePTFE) breathable membranes as the outer waterproof and breathable barrier, combined with cut-out silicone valves to achieve moisture-blocking opening and closing and daily low-pressure breathing. To suppress condensation inside the cavity, most solutions add bagged molecular sieve particles or moisture-absorbing cotton-like components to the breathing channel. In terms of airway layout, existing products mostly use a series or partially shared structure for the breathing channel and pressure relief channel, and breathing functional components are mostly independently externally arranged.

[0004] Existing technical solutions still have several shortcomings in practical applications: First, the microstructure of expanded polytetrafluoroethylene breathable membrane is a random fiber network structure, and the stress distribution on the membrane surface is uneven, resulting in a high dispersion of explosion-proof opening pressure. This can easily lead to problems such as false opening under low pressure or delayed opening under high pressure, making it difficult to meet the safety and accuracy requirements of the new generation of equipment. Second, under long-term high-temperature and high-low-temperature cycling environments of 85℃ to 120℃, the cut-type silicone valve plate is prone to molecular-level cold welding self-adhesion at the cut-fitting surface, causing the valve plate to fail to open normally under micro-pressure difference, resulting in the failure of the device's breathing function. Third, the built-in bagged or cotton-like moisture-absorbing components are not rigidly fixed, and dust is easily generated and shed under long-term vibration conditions, clogging the breathable membrane pores. In addition, traditional pore-forming moisture-absorbing materials often use chlorine-containing pore-forming agents, and the residual chloride ions can easily corrode the internal metal components. At the same time, the single-channel structure has the defects of high flow resistance and low moisture absorption efficiency. Fourth, the breathing and pressure relief air circuits are coupled and shared. When depressurizing, the high-pressure airflow directly washes over the breathing element, which not only affects the pressure relief flow and accuracy, but also easily causes the breathing element to shift and be damaged. In addition, the external breathing component results in a larger overall valve body size and poor installation adaptability. Summary of the Invention

[0005] This application provides a sealed cavity explosion-proof device with a built-in integrated breathing unit and its preparation method, in order to solve the existing technical problems of low pressure relief accuracy of explosion-proof pressure regulating devices, easy self-adhesion failure of silicone moisture barrier valve plates at high temperatures, serious powder shedding and high chloride ion residue of built-in moisture absorption components, and coupling interference between breathing and pressure relief gas paths.

[0006] In the first aspect, this application provides a sealed cavity explosion-proof device with a built-in integrated breathing unit, which includes, from top to bottom: a dirt-proof cover, a heavy ion microporous membrane assembly, a valve cover, a valve body, a hollow guide rod, a return spring, a moisture-proof valve plate, a moisture-absorbing column, and a rear cover; The hollow guide rod is slidably disposed in the central guide cavity of the valve body, and the return spring is disposed between the bottom of the hollow guide rod and the valve body to provide sealing pre-tightening force and return spring force; The moisture-blocking valve plate and the integrally formed moisture-absorbing column are embedded in the inner cavity of the hollow guide rod from top to bottom. The rear cover is sealed at the bottom of the inner cavity of the hollow guide rod, and a vent hole is reserved in the center to connect to the inside of the sealed cavity. The device is equipped with an independent central micro-breathing branch and an external main pressure relief branch.

[0007] Furthermore, the heavy ion microporous membrane is a track-etched membrane.

[0008] Furthermore, the moisture-barrier valve plate includes a circular silicone body; the center of the circular silicone body is provided with a through anti-adhesion micropore; a number of radial cuts extend evenly outward from the center of the anti-adhesion micropore; the circular silicone body is also provided with an annular thinning groove surrounding the anti-adhesion micropore, the depth of the annular thinning groove being 0.2 to 0.5 mm.

[0009] Furthermore, the outer diameter of the circular silicone body is 6 to 10 mm, and the thickness is 0.6 to 1.0 mm; the pore size of the anti-adhesion micropores is 0.3 to 0.5 mm; the length of a single radial cut is 2.5 to 5.0 mm; and the annular thinning groove is located at the root of the radial cut, with an inner diameter of 1.5 to 3.0 mm.

[0010] Furthermore, the circular silicone body is made of platinum vulcanized silicone rubber with a hardness of Shore A40 to 55 degrees; the moisture-blocking valve plate is sandwiched between the top surface of the hollow guide rod inner cavity and the integrally formed moisture-absorbing column.

[0011] Furthermore, the moisture-absorbing column is a hollow cylindrical rigid integral structure, which is a continuous porous skeleton formed by integral molding and curing of 4A molecular sieve functional powder and modified epoxy resin binder. The interior forms uniform and interconnected multi-level micron-level breathable channels with a porosity of 30% to 50%.

[0012] Furthermore, the raw material composition of the porous framework is as follows: 70 to 80 parts of low-chlorine ultrafine 4A molecular sieve, 18 to 25 parts of modified epoxy resin, 20 to 35 parts of potassium carbonate pore-forming agent, and 1 to 2 parts of silane coupling agent; the residual chloride ion content of the system is less than 10 ppm.

[0013] Furthermore, the potassium carbonate pore-forming agent adopts a two-stage particle size distribution of 50μm and 150μm, with a mass ratio of 4:6; after washing and elution with water, it forms a continuous and interconnected macroporous channel.

[0014] Furthermore, the modified epoxy resin is o-cresol-modified bisphenol F type epoxy resin, combined with a latent curing agent; the silane coupling agent is KH560 type, used to improve the interfacial bonding force between the molecular sieve and the epoxy group.

[0015] Furthermore, the hollow guide rod is a stepped hollow structure with a flange, with a central vent and guide post at the top, an outer circumferential sealing lip in the middle, and an installation cavity at the bottom.

[0016] Furthermore, the device controls the opening and closing of the peripheral main pressure relief branch through the axial displacement of the hollow guide rod, and controls the opening and closing of the central micro-breathing branch through the elastic deformation of the moisture-proof valve plate.

[0017] Secondly, this application provides a method for preparing a sealed cavity explosion-proof device with a built-in integrated breathing unit, comprising the following steps: Step 1: Ingredient mixing: After the low-chlorine ultrafine 4A molecular sieve is activated at high temperature and cooled under nitrogen protection, it is mixed with potassium carbonate pore-forming agent, modified epoxy resin, latent curing agent and silane coupling agent in a vacuum mixing equipment according to the mass ratio. After vacuum degassing, a uniform paste-like premix is ​​obtained. Step 2: Warm pressing: The premixed material is quantitatively injected into the molding mold with a central mandrel. After the mold is preheated, the molding process is carried out by segmented pressurization and venting. After demolding, a hollow cylindrical green body is obtained. Step 3: Step-by-step heating and curing: The green body is placed in a programmed heating equipment, and the resin cross-linking and curing is gradually completed by using a multi-stage step-by-step heating and heat preservation method. After slow cooling in the furnace, a rigid porous skeleton is formed. Step 4: Eluting and Gradient Drying: The solidified porous framework is placed in deionized water, and the soluble potassium carbonate pore-forming agent is eluted and removed using a negative pressure immersion circulation process to form continuous and interconnected multi-level channels; after elution, the internal moisture is removed using a gradient temperature drying process to obtain the finished moisture-absorbing column. Step 5: Finished product inspection and post-processing: The finished products are tested in sequence for size, porosity, air permeability resistance, dust loss and chloride ion residue. Qualified products are vacuum-packed for moisture protection after dust removal treatment.

[0018] Furthermore, in step 1, the molecular sieve activation conditions are: oven heating at 380℃ for 2 hours, with nitrogen protection throughout the cooling process; a double planetary vacuum stirrer is used, with a mixing time of 10 to 15 minutes, followed by vacuum degassing for at least 20 minutes; cooling water is used during the mixing process to control the material temperature to ≤40℃; the potassium carbonate pore-forming agent needs to be ground through a 200-mesh sieve before mixing; in step 2, the inner wall of the mold is coated with a Teflon non-stick coating, and the surface of the mandrel is mirror-polished; in step 4, the gradient drying process is: first drying at 60℃ for 2 hours, then heating to 100℃ for 2 hours, and finally heating to 120℃ for 1 hour.

[0019] The technical solutions provided in this application have the following advantages compared with the prior art: 1. Significantly improved pressure relief accuracy and flexible air permeability configuration: The pore size uniformity of the heavy ion direct-pore membrane is good, which can stably control the explosion-proof opening pressure deviation within ±5%, which is better than the control level of traditional expanded polytetrafluoroethylene membranes, and helps to reduce the risk of accidental opening and delayed opening; at the same time, the air permeability can be customized by adjusting the membrane pore size and porosity parameters to meet the needs of multiple scenarios and improve the versatility of the product.

[0020] 2. Effectively improves high-temperature adhesion problems and has excellent micro-pressure opening and closing performance: The central anti-adhesion microporous structure can physically destroy the stress conditions of silicone self-adhesion. High-temperature aging verification shows that it can significantly reduce the probability of incision adhesion failure. Combined with the flexible hinge formed by the root annular thinning groove, it can reduce the bending stiffness of the valve and stabilize the opening pressure in the range of 0.3 to 1.0 kPa. It can accurately respond to the micro-pressure difference caused by daily temperature changes and improve respiratory balance sensitivity.

[0021] 3. Low powder shedding and low chlorine residue, with high moisture absorption efficiency through multi-level channels: The integrated molding process can stably lock the molecular sieve in the epoxy matrix. Vibration tests show that the amount of powder shedding is low, which can effectively reduce the risk of clogging of the breathable membrane. The potassium carbonate pore-forming system constructs a through-pore mass transfer network, and the volumetric moisture absorption density is significantly improved compared with bagged molecular sieve particles of the same volume. The use of a chlorine-free pore-forming system results in low chloride ion residue, which helps to reduce the risk of corrosion of metal parts.

[0022] 4. High structural integration and effective decoupling of dual air paths: The breathing function unit is completely embedded in the piston cavity, which helps to reduce the axial dimension of the valve body and improve the structural compactness; the breathing branch and the pressure relief branch are physically separated, and the pressure relief airflow can avoid the internal breathing element, which helps to ensure the flow and accuracy of large-diameter pressure relief, and also avoids the displacement and damage of functional components caused by high-pressure airflow, thus improving operational reliability.

[0023] 5. Improved moisture protection: The dual effects of physical moisture barrier and physical moisture absorption can maintain a low humidity inside the cavity during damp heat testing, reduce the risk of condensation, and help extend the electrical insulation life of the sealed cavity and the service life of core components. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0027] Figure 1 An explosion diagram of a sealed cavity explosion-proof device with a built-in integrated breathing unit provided in an embodiment of this application.

[0028] Figure 2 This is a cross-sectional schematic diagram of a sealed cavity explosion-proof device with a built-in integrated breathing unit provided in an embodiment of this application.

[0029] Figure 3 This is a schematic diagram of the moisture barrier valve plate.

[0030] Figure 4 This is a schematic diagram of the hollow guide rod.

[0031] Figure 5 This is a schematic diagram of the gas path in the static moisture-proof state of the explosion-proof device.

[0032] Figure 6 This is a schematic diagram of the gas path for the low-pressure positive pressure exhaust of the explosion-proof device.

[0033] Figure 7 This is a schematic diagram of the air path for the low-pressure negative pressure air intake of the explosion-proof device.

[0034] Figure 8 A schematic diagram of the gas path for emergency explosion-proof pressure relief of the explosion-proof device.

[0035] Figure 9 A process flow diagram of a sealed cavity explosion-proof device with a built-in integrated breathing unit and its preparation method provided in this application embodiment.

[0036] Explanation of reference numerals in the attached figures: 1. Anti-fouling cover; 2. Test iron sheet; 3. Pressure ring; 4. Heavy ion microporous membrane; 5. Valve cover; 6. Inner sealing ring; 7. Valve body; 8. Outer sealing ring; 9. Hollow guide rod; 10. Return spring; 11. Moisture-barrier valve plate; 111. Anti-adhesion micropores; 112. Radial cuts; 113. Annular thinning groove; 12. Moisture-absorbing column; 13. Rear cover. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0039] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0040] To address the existing technical problems of low pressure relief accuracy in explosion-proof pressure regulating devices, easy self-adhesion failure of silicone moisture-proof valve plates at high temperatures, severe powder shedding and high chloride ion residue in built-in moisture-absorbing components, and coupling interference between breathing and pressure relief gas paths, this application provides a sealed cavity explosion-proof device with a built-in integrated breathing unit and its preparation method. This device achieves improved pressure relief accuracy, enhanced high-temperature anti-adhesion performance, low powder shedding and low chloride residue in the moisture-absorbing components, and independent gas path functions without interference through an integrated structural design with decoupled dual gas paths, the application of heavy ion microporous membranes, optimization of the anti-adhesion moisture-proof valve plate structure, and improvement of the material and process of the moisture-absorbing column.

[0041] Please see Figures 1 to 8 In the first aspect, this application provides a sealed cavity explosion-proof device with a built-in integrated breathing unit, which includes, from top to bottom: a dirt cover 1, a heavy ion microporous membrane 4 assembly, a valve cover 5, a valve body 7, a hollow guide rod 9, a reset spring 10, a moisture-proof valve plate 11, a moisture-absorbing column 12, and a rear cover 13. The hollow guide rod 9 is slidably disposed in the central guide cavity of the valve body 7, and the reset spring 10 is disposed between the bottom of the hollow guide rod 9 and the valve body 7 to provide sealing pre-tightening force and reset spring force; The moisture-blocking valve plate 11 and the integrally formed moisture-absorbing column 12 are embedded in the inner cavity of the hollow guide rod 9 from top to bottom. The rear cover 13 is sealed at the bottom of the inner cavity of the hollow guide rod 9, and a vent hole is reserved in the center to connect to the inside of the sealed cavity. The device is equipped with an independent central micro-breathing branch and an outer main pressure relief branch. During normal breathing, airflow flows along the micro-breathing branch on the central axis of the hollow guide rod 9, passing sequentially through the moisture-blocking valve 11 and the moisture-absorbing column 12 to achieve moisture blocking and dehumidification. During overpressure relief, the hollow guide rod 9 overcomes the spring force and shifts axially, opening the annular main pressure relief branch outside the piston, allowing airflow to bypass the internal breathing elements and achieve rapid pressure relief over a large diameter. In the embodiment provided in this application, all moisture-blocking and moisture-absorbing elements are embedded inside the hollow guide rod 9. Normal breathing uses the central branch, while overpressure relief uses the outer annular channel, achieving functional independence. The device as a whole, from top to bottom, includes a dirt-proof cover 1, a heavy ion microporous membrane 4 assembly, a valve cover 5, a valve body 7, an outer sealing ring 8, a hollow guide rod 9, a return spring 10, a moisture-blocking valve 11, a moisture-absorbing column 12, and a rear cover 13. The hollow guide rod 9 is the core bearing component. Its internal cavity houses the moisture-blocking valve plate 11 and the moisture-absorbing column 12 from top to bottom. The bottom is limited and fixed by the rear cover 13, forming an integrated micro-breathing unit. The outer periphery of the hollow guide rod 9 and the inner wall of the valve body 7 form a main pressure relief sealing pair, which is closed under normal conditions. When there is overpressure, the piston is axially displaced to open the outer large-diameter pressure relief channel.

[0042] In some optional embodiments, the heavy ion microporous membrane 4 is a track-etched membrane, using PET or PI as a substrate, with straight cylindrical through-holes formed by high-energy heavy ion irradiation and chemical etching, having a pore size of 0.05 to 15 μm and an open area ratio of 10% to 20%; the air permeability of the device is configured by adjusting the structural parameters of pore size and / or open area ratio. The heavy ion microporous membrane 4 uses PET or PI polymer substrate, with uniform and straight cylindrical through-holes formed by high-energy heavy ion irradiation combined with precision chemical etching. This structure has good pore size uniformity and relatively uniform stress distribution on the membrane surface, which helps to improve the stability of the explosion-proof opening pressure; by precisely controlling the structural parameters of pore size and open area ratio, the breathing flow requirements of different devices can be customized to achieve flexible configuration of air permeability.

[0043] In some optional embodiments, the moisture-blocking valve plate 11 includes a circular silicone body; the center of the circular silicone body is provided with a through anti-adhesion micropore 111; a plurality of radial cuts 112 extend uniformly outward from the center of the anti-adhesion micropore 111; the circular silicone body is also provided with an annular thinning groove 113 surrounding the anti-adhesion micropore 111, the depth of the annular thinning groove 113 being 0.2 to 0.5 mm; under zero pressure difference, the multi-valve relies on elastic closure, with only the central micropore slightly open; when the pressure difference reaches 0.3 to 1.0 kPa, the valve elastically and uniformly opens towards the low-pressure side along the annular thinning groove 113, achieving bidirectional air permeability. The outer diameter of the circular silicone body is 6 to 10 mm, and the thickness is 0.6 to 1.0 mm; the pore size of the anti-adhesion micropores 111 is 0.3 to 0.5 mm; the length of a single radial slit 112 is 2.5 to 5.0 mm; the annular thinning groove 113 is located at the root of the radial slits 112, and the inner diameter of the groove is 1.5 to 3.0 mm. The circular silicone body is made of platinum vulcanized silicone rubber with a hardness of Shore A 40 to 55 degrees; the moisture-blocking valve plate 11 is sandwiched between the top surface of the inner cavity of the hollow guide rod 9 and the integrally formed moisture-absorbing column 12.

[0044] The anti-adhesion micropores 111 physically sever the continuous contact surface of the radial cuts 112 at the center, disrupting the stress continuity of the cut contact surface and reducing the probability of silicone molecules self-adhesion under high temperature from a structural perspective. The annular thinning groove 113 reduces the effective bending thickness at the valve root, forming a flexible hinge structure. While maintaining the overall thickness and structural strength of the valve's outer sealing area, it reduces the valve's bending stiffness, allowing the valve to undergo uniform bending deformation along the annular groove under micro-pressure differential, achieving low-pressure opening and high-rebound reset performance. The moisture-blocking valve plate 11 is sandwiched between the top surface of the hollow guide rod 9's inner cavity and the moisture-absorbing column 12. The elastic silicone body can absorb axial vibration impact, providing a flexible buffer and limiting effect on the moisture-absorbing column 12, reducing the possibility of debris generated by hard contact wear.

[0045] In some optional embodiments, the moisture-absorbing column 12 is a hollow cylindrical rigid integral structure, which is a continuous porous skeleton formed by integral molding and curing of 4A molecular sieve functional powder and modified epoxy resin binder. The interior forms uniform and interconnected multi-level micron-level air-permeable channels with a porosity of 30% to 50%. By mass, the raw material composition of the porous skeleton is: 70 to 80 parts of low-chlorine ultrafine 4A molecular sieve, 18 to 25 parts of modified epoxy resin, 20 to 35 parts of potassium carbonate pore-forming agent, and 1 to 2 parts of silane coupling agent; the residual chloride ion content of the system is <10 ppm.

[0046] In some optional embodiments, the potassium carbonate pore-forming agent adopts a two-stage particle size distribution of 50μm and 150μm, with a mass ratio of 4:6; after washing and elution with water, it forms a continuous and interconnected macroporous channel.

[0047] In some optional embodiments, the modified epoxy resin is o-cresol-modified bisphenol F type epoxy resin, combined with a latent curing agent; the silane coupling agent is KH560 type, used to improve the interfacial bonding force between the molecular sieve and the epoxy group.

[0048] The moisture-absorbing column 12 is a hollow cylindrical rigid structure, formed by premixing, warm-pressing, step-curing, and eluting low-chlorine ultrafine 4A molecular sieve powder with modified epoxy resin to create a continuous, interconnected, multi-level porous framework. The molecular sieve powder can be ultrafine with a D50 particle size of 2 to 5 μm, and the internal macropore channels are interconnected, allowing airflow to pass axially through the column from the end face. The raw material system uses potassium carbonate as a pore-forming agent, employing a two-stage particle size distribution to construct large-size diffusion channels. After water washing and elution, it forms continuous, interconnected macropore channels, improving moisture absorption efficiency with low flow resistance. The pore-forming system does not introduce additional chlorine, reducing the residual chloride ion content. A matching silane coupling agent improves the interfacial bonding between the molecular sieve and the epoxy resin, enhancing the overall structural strength and vibration resistance of the framework.

[0049] In some optional embodiments, the hollow guide rod 9 is a stepped hollow structure with a flange, featuring a central vent and guide post at the top, an outer sealing lip in the middle, and an inner mounting cavity at the bottom. Under normal conditions, the return spring 10 pushes the hollow guide rod 9 upwards, causing the sealing lip to fit tightly against the inner wall of the valve body 7, blocking the main pressure relief branch on the periphery. In case of overpressure, the hollow guide rod 9 moves upwards as a whole, the sealing lip separates, and the large annular diameter fully opens, achieving rapid pressure relief.

[0050] In some optional embodiments, the device controls the opening and closing of the peripheral main pressure relief branch through the axial displacement of the hollow guide rod 9, and controls the opening and closing of the central micro-breathing branch through the elastic deformation of the moisture-blocking valve plate 11, thereby achieving four-level working state switching: static moisture blocking, micro-pressure positive pressure exhaust, micro-pressure negative pressure intake, and emergency explosion-proof pressure relief; after the pressure drops to the threshold, the hollow guide rod 9 can automatically reset. The device can automatically switch between four working states according to the internal and external pressure difference, namely static moisture blocking, micro-pressure positive pressure exhaust, micro-pressure negative pressure intake, and emergency explosion-proof pressure relief. During normal breathing, the airflow flows along the central axis of the piston throughout, connecting all moisture-blocking and moisture-absorbing elements in series; during overpressure relief, the piston moves axially as a whole, opening the peripheral annular large diameter, and the airflow bypasses the internal breathing elements, so the pressure relief and breathing functions do not interfere with each other.

[0051] Please see Figure 9 Secondly, this application provides a method for preparing a sealed cavity explosion-proof device with a built-in integrated breathing unit, comprising the following steps: Step 1: Ingredient mixing: After the low-chlorine ultrafine 4A molecular sieve is activated at high temperature and cooled under nitrogen protection, it is mixed with potassium carbonate pore-forming agent, modified epoxy resin, latent curing agent and silane coupling agent in a vacuum mixing equipment according to the mass ratio. After vacuum degassing, a uniform paste-like premix is ​​obtained. Step 2: Warm pressing: The premixed material is quantitatively injected into the molding mold with a central mandrel. After the mold is preheated, the molding process is carried out by segmented pressurization and venting. After demolding, a hollow cylindrical green body is obtained. Step 3: Step-by-step heating and curing: The green body is placed in a programmed heating equipment, and the resin cross-linking and curing is gradually completed by using a multi-stage step-by-step heating and heat preservation method. After slow cooling in the furnace, a rigid porous skeleton is formed. Step 4: Eluting and Gradient Drying: The solidified porous framework is placed in deionized water, and the soluble potassium carbonate pore-forming agent is eluted and removed using a negative pressure immersion circulation process to form continuous and interconnected multi-level channels; after elution, the internal moisture is removed using a gradient temperature drying process to obtain the finished moisture-absorbing column. Step 5: Finished product inspection and post-processing: The finished products are tested in sequence for size, porosity, air permeability resistance, dust loss and chloride ion residue. Qualified products are vacuum-packed for moisture protection after dust removal treatment.

[0052] In some optional embodiments, the molecular sieve activation conditions in step 1 are: oven heating at 380℃ for 2 hours, with nitrogen protection throughout the cooling process; a dual planetary vacuum stirrer is used, with a mixing time of 10 to 15 minutes, followed by vacuum degassing for at least 20 minutes; cooling water is used during the mixing process to control the material temperature to ≤40℃; the potassium carbonate pore-forming agent needs to be ground through a 200-mesh sieve before mixing; in step 2, the inner wall of the mold is coated with a Teflon non-stick coating, and the mandrel surface is mirror-polished; the gradient drying process in step 4 is: first drying at 60℃ for 2 hours, then heating to 100℃ for 2 hours, and finally heating to 120℃ for 1 hour; in high-requirement scenarios, TOC detection is added to assist in determining the elution endpoint, requiring TOC ≤5mg / L.

[0053] Working principle description I. Working principle of dual-air-path decoupling This invention utilizes the piston-like structure of the hollow guide rod 9 to completely physically separate the breathing air path from the pressure relief air path. Under normal low-pressure conditions, the hollow guide rod 9 remains closed under the preload of the spring, blocking the main pressure relief channel on the periphery. Airflow can only pass through the micro-breathing branch in the center of the hollow guide rod 9, passing sequentially through the moisture-absorbing and moisture-blocking elements to achieve gas drying and moisture-blocking protection. When the internal pressure of the cavity suddenly rises to the explosion-proof threshold, the gas pressure acts on the lower end face of the hollow guide rod 9, overcoming the spring force and pushing the guide rod axially upward. The outer annular large diameter is fully opened, and the high-pressure gas is directly discharged from the outer channel without contacting the internal breathing element. This ensures both the pressure relief flow rate and response speed, while avoiding the impact damage of the high-pressure airflow to the precision breathing element.

[0054] II. Moisture Barrier Valve Plate 11: Anti-Stickness and Flexible Opening / Closing Principle The central anti-adhesion micropore 111 severs the continuous bonding surface where the radial incisions 112 converge at the center, disrupting the continuous interface through which silicone molecules undergo cold welding diffusion under compressive stress, thus reducing the conditions for self-adhesion from the structural root. Simultaneously, the annular thinning groove 113 concentrates the bending deformation of the valve in the thin area at the root of the groove, reducing the pressure required for opening and also reducing the bonding pressure on the incision bonding surface, further reducing the risk of adhesion. When the valve opens, it bends evenly along the annular groove, resulting in uniform stress distribution and good consistency in opening and closing rebound.

[0055] III. Multi-level pore structure moisture absorption and mass transfer principle After elution, potassium carbonate pore-forming agent forms a continuous macroporous channel structure: the macroporous channel serves as the main channel for gas diffusion, reducing the overall flow resistance and ensuring rapid gas passage; at the same time, the macroporous channel increases the exposed adsorption interface of the molecular sieve, improving the moisture absorption efficiency and adsorption capacity, forming a "diffusion-adsorption" mass transfer network. Compared with moisture-absorbing materials with a single pore size, it has a higher moisture absorption rate and capacity in the same volume, while having lower flow resistance and not affecting the breathing permeability of the device.

[0056] Example 1: Standard Explosion-proof Pressure Regulator for Passenger Vehicles This embodiment is a standard sealed cavity explosion-proof pressure regulating device with F50 installation specifications, suitable for scenarios such as power battery packs, energy storage boxes, and communication cabinets. The overall structure is as follows. Figure 1 , Figure 2 As shown, from top to bottom, it includes: anti-fouling cover 1, test iron sheet 2, pressure ring 3, heavy ion microporous membrane 4, valve cover 5, inner sealing ring 6, valve body 7, outer sealing ring 8, hollow guide rod 9, reset spring 10, moisture barrier valve plate 11, moisture absorption column 12, and rear cover 13.

[0057] Key parameters for this embodiment: Heavy ion microporous membrane 4: PET substrate heavy ion track etching membrane, pore size 2μm, porosity 15%; uniform stress on the membrane surface, explosion-proof opening pressure deviation ≤±5%, protection level up to IP68, IPX9K.

[0058] Moisture-barrier valve 11: 8mm outer diameter, 0.8mm overall thickness, made of platinum-cured high-tear-resistance silicone rubber with a Shore A48 hardness; a Φ0.4mm through-hole anti-adhesion micropore 111 is opened in the center, extending into several radial slits 112 to form a multi-valve structure, with a single slit length of 3.5mm and an R0.2mm crack-resistant fillet at the outer end of the slit; an annular thinning groove 113 is provided around the micropore at the root of the slit, with a groove depth of 0.3mm and an inner diameter of 2.0mm, reducing the effective bending thickness at the valve root to 0.5mm, forming a continuous flexible hinge. The valve is installed in the upper part of the inner cavity of the hollow guide rod 9, and has the functions of moisture barrier, opening and closing, and axial buffering.

[0059] One-piece molded moisture-absorbing column 12: outer diameter 8mm, inner diameter 4mm, height 7.2mm, concentricity of inner and outer circles ≤0.05mm, overall porosity 45%; raw materials by mass: 78 parts D50 3μm low-chlorine 4A molecular sieve, 20 parts o-cresol formaldehyde modified bisphenol F epoxy resin, 28 parts potassium carbonate pore-forming agent, 2 parts KH560 silane coupling agent; potassium carbonate adopts a two-stage particle size distribution of 50μm and 150μm, with a mass ratio of 4:6, and is ground through a 200-mesh sieve before mixing; residual chloride ion content of finished product <10ppm.

[0060] Hollow guide rod 9: made of aluminum alloy, with an inner cavity diameter of 8.4mm and a single-sided gap of 0.2mm between it and the moisture-absorbing column 12; the width of the sealing lip on the outer periphery of the middle part is 1.2mm, which is in close contact with the inner wall of the valve body 7 under normal conditions.

[0061] Performance indicators: Explosion-proof opening pressure 4±0.2kPa; positive pressure air permeability ≥320ml / min@2.5kPa; moisture barrier valve 11 positive pressure opening 0.5 to 1.0kPa, negative pressure opening 1.0 to 3.0kPa.

[0062] The four-level working process in this embodiment: In static moisture-blocking mode: when the internal and external pressure difference is ≤0.5kPa, the return spring 10 pushes the hollow guide rod 9 upward, causing the outer sealing lip to adhere to the inner wall of the valve body 7, and the outer main pressure relief branch is completely closed; the multi-valve membrane of the moisture-blocking valve plate 11 closes naturally due to elasticity, with only the central micropore maintaining a very small amount of conduction. At this time, there is no directional airflow, and the diffusion of external water vapor is physically blocked by the moisture-blocking valve plate 11. The residual water vapor in the piston cavity is continuously adsorbed by the moisture-absorbing column 12, maintaining a low humidity baseline in the cavity; at the same time, the moisture-blocking valve plate 11 forms a flexible buffer for the moisture-absorbing column 12 below, absorbing vibration impact.

[0063] Micro-pressure positive pressure exhaust state: When the equipment heats up and the pressure inside the cavity rises to 0.5 to 1.5 kPa, the hollow guide rod 9 remains closed; the gas inside the cavity enters through the central hole of the rear cover 13, first flows through the moisture-absorbing column 12, and the molecular sieve desorbs moisture by heating to achieve self-regeneration. Then the gas pushes upward to open the multi-valve membrane of the moisture-blocking valve plate 11, passes through the central through hole at the top of the hollow guide rod 9 and the upper cavity of the valve cover 5, and is finally discharged to the outside through the heavy ion microporous membrane 4 to balance the internal pressure.

[0064] Micro-pressure negative pressure air intake state: When the equipment cools down to form a negative pressure, and the external pressure difference reaches 1.0 to 3.5 kPa, the hollow guide rod 9 remains closed; the outside air first passes through the heavy ion microporous membrane 4 to filter liquid water and dust, and then through the central hole at the top of the hollow guide rod 9 to push down the multi-valve membrane of the moisture barrier valve plate 11, enters the moisture absorption column 12 to complete deep drying, and finally enters the cavity through the central hole of the rear cover 13 to achieve air intake drying.

[0065] Emergency explosion-proof pressure relief state: When thermal runaway causes the internal pressure to rise above 4 kPa, the internal pressure acts on the lower end face of the hollow guide rod 9, overcoming the preload of the return spring 10 and pushing the hollow guide rod 9 upward axially; the outer circumferential sealing lip of the piston completely separates from the inner wall of the valve body 7, and the outer annular large-diameter main pressure relief branch is fully open. High-pressure gas is directly discharged rapidly through the annular channel on the outer side of the piston, the main pressure relief chamber of the valve body 7, and the heavy ion microporous membrane 4, bypassing the internal breathing element to complete the pressure relief. After the pressure drops below the threshold, the piston automatically resets under the action of the spring, restoring the moisture-proof breathing state.

[0066] Preparation Example of Moisture Absorbing Column 12 The manufacturing process of the integrally molded moisture-absorbing column 12 in this embodiment is as follows: Figure 7 As shown, the specific steps are as follows: Ingredient Mixing: Weigh each raw material according to the mass ratio; first, place the D503μm low-chlorine 4A molecular sieve in a 380℃ oven for 2 hours to fully remove crystal water and adsorbed water, and cool to room temperature under nitrogen protection; then premix the molecular sieve and potassium carbonate at low speed for 5 minutes, and then add o-cresol formaldehyde modified bisphenol F epoxy resin, latent curing agent, and silane coupling agent. Before mixing, the potassium carbonate is ground through a 200-mesh sieve and put into a double planetary vacuum mixer. Premix at low speed for 5 minutes, shear mix at high speed for 10 minutes, and finally degas under vacuum for 20 minutes to make a uniform, bubble-free paste premix; cooling water is circulated throughout the mixing process to control the material temperature ≤40℃.

[0067] Warm pressing: The premixed material is filled into a carbide mold with a double guide mandrel using a precision quantitative injection device. The mandrel diameter is 4mm and the outer diameter of the mold cavity is 8mm. The mold is preheated to 70℃ and a segmented pressurization and venting process is adopted: first, the pre-pressurizes and vents twice at 5MPa, and then increases to 8MPa and holds for 45s. The inner wall of the mold is coated with Teflon non-stick coating and the mandrel is mirror polished. After demolding, a green blank with uniform wall thickness is obtained.

[0068] Stepped heating and curing: The green body is laid flat in a programmed heating oven and cured in three stages: heating to 80℃ at 1℃ / min and holding for 2 hours for initial setting, then heating to 120℃ and holding for 3 hours for deep cross-linking, and finally heating to 140℃ and holding for 1 hour for curing; the entire process is slow cooling with the oven to eliminate internal thermal stress and form a rigid porous skeleton.

[0069] Elution and Gradient Drying: The cured column was placed in 70℃ deionized water and eluted using a negative pressure immersion circulation process at a vacuum of -0.085MPa. The deionized water was replaced every 30 minutes, and the conductivity of the immersion solution was monitored in real time until the conductivity was <5μS / cm, confirming complete elution of the pore-forming agent and the formation of continuous, interconnected multi-level channels. After elution, gradient drying was performed: first, drying at 60℃ for 2 hours, then increasing the temperature to 100℃ for 2 hours, and finally increasing the temperature to 120℃ for 1 hour to slowly remove internal moisture and avoid thermal stress on the framework. Finally, ion chromatography analysis showed that the residual chloride ion content in the system was <10ppm; for high-requirement scenarios, TOC detection can be added, requiring TOC ≤5mg / L.

[0070] Finished product inspection: The appearance, dimensions, porosity, air resistance, high-pressure air blowing dust amount, and chloride ion residue are tested in sequence. Qualified products are vacuum-packed and stored after high-pressure pulse air blowing dust removal.

[0071] Example 2: Extended Explosion-proof Pressure Regulator for High Humidity Energy Storage Scenarios This embodiment is an F50 installation specification explosion-proof pressure regulating device adapted to high humidity energy storage scenarios. The overall assembly structure from top to bottom includes: anti-fouling cover 1, test iron plate 2, pressure ring 3, heavy ion microporous membrane 4, valve cover 5, inner sealing ring 6, valve body 7, outer sealing ring 8, hollow guide rod 9, reset spring 10, moisture barrier valve plate 11, moisture absorption column 12, and rear cover 13.

[0072] Key parameters for this embodiment: Heavy ion microporous membrane 4: PET substrate heavy ion track etching membrane, pore size 2μm, porosity 15%; uniform stress on the membrane surface, explosion-proof opening pressure deviation ≤±5%, protection level up to IP68, IPX9K.

[0073] Moisture-barrier valve 11: 8mm outer diameter, 0.6mm overall thickness, made of platinum-cured high-tear-resistance silicone rubber with a hardness of Shore A48; a Φ0.4mm through-hole anti-adhesion micropore 111 is opened in the center, extending into several radial slits 112 to form a multi-valve structure, with a single slit length of 3.5mm and an R0.2mm crack-resistant fillet at the outer end of the slit; an annular thinning groove 113 is provided around the micropore at the root of the slit, with a groove depth of 0.3mm and an inner diameter of 2.0mm, reducing the effective bending thickness at the valve root to 0.3mm, forming a continuous flexible hinge. The valve is installed in the upper part of the inner cavity of the hollow guide rod 9, and has the functions of moisture barrier, opening and closing, and axial buffering.

[0074] One-piece molded moisture-absorbing column 12: outer diameter 8mm, inner diameter 4mm, height 20mm, concentricity of inner and outer circles ≤0.05mm, overall porosity approximately 50%; raw materials by mass: 78 parts D50 3μm low-chlorine 4A molecular sieve, 20 parts o-cresol formaldehyde modified bisphenol F epoxy resin, 32 parts potassium carbonate pore-forming agent, 2 parts KH560 silane coupling agent; potassium carbonate uses a two-stage particle size distribution of 50μm and 150μm, with a mass ratio of 4:6, and is ground through a 200-mesh sieve before mixing; residual chloride ion content in the finished product <10ppm.

[0075] Hollow guide rod 9: made of aluminum alloy, with an inner cavity diameter of 8.4mm. The inner cavity height is adjusted to match the size of the moisture absorption column 12, with a single-sided gap of 0.2mm between it and the moisture absorption column 12. The width of the sealing lip on the outer periphery of the middle part is 1.2mm, which is tightly fitted to the inner wall of the valve body 7 under normal conditions.

[0076] Performance indicators: Explosion-proof opening pressure 4±0.2kPa; positive pressure air permeability ≥320ml / min@2.5kPa; moisture absorption capacity is increased by about 120% compared with the standard model, and it can maintain the anti-condensation effect for a longer period of time in high humidity environment.

[0077] The four-stage working process in this embodiment is the same as in embodiment 1. Under static moisture-proof conditions, the moisture-absorbing column 12 can absorb more residual moisture in the inner cavity. During the micro-pressure positive and negative pressure breathing process, the longer moisture-absorbing column 12 can improve the gas drying depth and better meet the long-term anti-condensation requirements of energy storage boxes in high-humidity areas. Under emergency explosion-proof pressure relief conditions, the main external pressure relief branch is fully opened, and the high-pressure airflow bypasses the internal breathing element and is quickly discharged to ensure pressure relief safety.

[0078] Example 3: Explosion-proof pressure regulating device with multi-microporous anti-adhesion valve plate This embodiment is an F50-specification explosion-proof pressure regulating device adapted to high-temperature cyclic operating conditions. The overall assembly structure, from top to bottom, includes: 1. Anti-fouling cover, 2. Test iron plate, 3. Pressure ring, 4. Heavy ion microporous membrane, 5. Valve cover, 6. Inner sealing ring, 7. Valve body, 8. Outer sealing ring, 9. Hollow guide rod, 10. Reset spring, 11. Moisture-blocking valve plate, 12. Moisture-absorbing column, and 13.

[0079] Key parameters for this embodiment: Heavy ion microporous membrane 4: PET substrate heavy ion track etching membrane, pore size 2μm, porosity 15%; uniform stress on the membrane surface, explosion-proof opening pressure deviation ≤±5%, protection level up to IP68, IPX9K.

[0080] Moisture-barrier valve 11: 8mm outer diameter, 0.6mm overall thickness, made of platinum-cured high-tear-resistance silicone rubber with a hardness of Shore A48; three through-hole anti-adhesion micropores 111 are evenly arranged circumferentially along the inner side of the annular thinning groove 113, each micropore having a diameter of 0.3mm. Several radially distributed slits 112 extend outwards from each micropore, forming a multi-valve structure. Each slit is 3.5mm long, with a 0.2mm radius corner at the outer end to prevent cracking. An annular thinning groove 113 surrounds the micropore area at the root of the slits, with a depth of 0.3mm and an inner diameter of 2.0mm, effectively reducing the bending thickness at the valve root to 0.3mm, forming a continuous flexible hinge. The valve is installed on the upper part of the hollow guide rod 9, serving multiple functions including moisture barrier, opening / closing, and axial buffering.

[0081] One-piece molded moisture-absorbing column 12: outer diameter 8mm, inner diameter 4mm, height 7.2mm, concentricity of inner and outer circles ≤0.05mm, overall porosity 45%; raw materials by mass: 78 parts D50 3μm low-chlorine 4A molecular sieve, 20 parts o-cresol formaldehyde modified bisphenol F epoxy resin, 28 parts potassium carbonate pore-forming agent, 2 parts KH560 silane coupling agent; potassium carbonate adopts a two-stage particle size distribution of 50μm and 150μm, with a mass ratio of 4:6, and is ground through a 200-mesh sieve before mixing; residual chloride ion content of finished product <10ppm.

[0082] Hollow guide rod 9: made of aluminum alloy, with an inner cavity diameter of 8.4mm and a single-sided gap of 0.2mm between it and the moisture-absorbing column 12; the width of the sealing lip on the outer periphery of the middle part is 1.2mm, which is in close contact with the inner wall of the valve body 7 under normal conditions.

[0083] Performance indicators: Explosion-proof opening pressure 4±0.2kPa; positive pressure air permeability ≥320ml / min@2.5kPa; after 120℃ high temperature aging test, the probability of cut adhesion failure is further reduced compared with single microporous structure, and the opening and closing stability is better under high temperature conditions.

[0084] The four-level working process in this embodiment is the same as that in Embodiment 1. The multi-microporous structure can more comprehensively cut off the stress continuity at the root of the cut, improve the anti-adhesion redundancy, and maintain stable micro-pressure opening and closing performance under more severe long-term high-temperature cycling conditions. It is suitable for industrial power distribution cabinet scenarios that operate at high temperatures for a long time.

[0085] Example 4: 12 Explosion-proof Pressure Regulating Devices for Plug-in Modular Moisture Absorption Columns This embodiment is an F50 installation specification explosion-proof pressure regulating device adapted to high operation and maintenance scenarios. The overall assembly structure from top to bottom includes: anti-fouling cover 1, test iron plate 2, pressure ring 3, heavy ion microporous membrane 4, valve cover 5, inner sealing ring 6, valve body 7, outer sealing ring 8, hollow guide rod 9, reset spring 10, moisture barrier valve plate 11, pluggable modular moisture absorption column 12, and rear cover 13.

[0086] Key parameters for this embodiment: Heavy ion microporous membrane 4: PET substrate heavy ion track etching membrane, pore size 2μm, porosity 15%; uniform stress on the membrane surface, explosion-proof opening pressure deviation ≤±5%, protection level up to IP68, IPX9K.

[0087] Moisture-barrier valve 11: 8mm outer diameter, 0.6mm overall thickness, made of platinum-cured high-tear-resistance silicone rubber with a hardness of Shore A48; a Φ0.4mm through-hole anti-adhesion micropore 111 is opened in the center, extending into several radial slits 112 to form a multi-valve structure, with a single slit length of 3.5mm and an R0.2mm crack-resistant fillet at the outer end of the slit; an annular thinning groove 113 is provided around the micropore at the root of the slit, with a groove depth of 0.3mm and an inner diameter of 2.0mm, reducing the effective bending thickness at the valve root to 0.3mm, forming a continuous flexible hinge. The valve is installed in the upper part of the inner cavity of the hollow guide rod 9, and has the functions of moisture barrier, opening and closing, and axial buffering.

[0088] The pluggable modular moisture-absorbing column 12 has an outer diameter of 8mm, an inner diameter of 4mm, and a height of 7.2mm. The concentricity of the inner and outer circles is ≤0.05mm, and the overall porosity is 45%. The raw materials, by weight, are: 78 parts D50 3μm low-chlorine 4A molecular sieve, 20 parts o-cresphenol-modified bisphenol F epoxy resin, 28 parts potassium carbonate pore-forming agent, and 2 parts KH560 silane coupling agent. The potassium carbonate uses a two-stage particle size distribution of 50μm and 150μm, with a mass ratio of 4:6. The residual chloride ion content in the finished product is <10ppm. The hollow guide rod 9 has a corresponding quick-installation locking structure, allowing the moisture-absorbing column 12 to be directly plugged in and installed from the bottom of the guide rod without disassembling the entire valve body 7.

[0089] Hollow guide rod 9: made of aluminum alloy, with an inner cavity diameter of 8.4mm, built-in quick-release clip, and a single-sided gap of 0.2mm with the moisture-absorbing column 12; the width of the sealing lip on the outer periphery of the middle part is 1.2mm, which fits tightly against the inner wall of the valve body 7 under normal conditions.

[0090] Performance indicators: Explosion-proof opening pressure 4±0.2kPa; positive pressure air permeability ≥320ml / min@2.5kPa; moisture absorption column 12 replacement operation time ≤30 seconds, significantly improving operation and maintenance efficiency.

[0091] The four-level working process in this embodiment is the same as in embodiment 1. The daily breathing and explosion-proof pressure relief functions are not affected by the modular structure. During the maintenance cycle, the rear cover 13 can be directly removed to quickly replace the moisture-absorbing column 12 module without disassembling the entire explosion-proof pressure regulating device. It is suitable for scenarios with high operation and maintenance frequency, such as commercial vehicles and energy storage power stations, and can effectively reduce the later maintenance costs.

[0092] Example 5: Explosion-proof pressure regulating device with engineering plastic guide rod This embodiment is an explosion-proof pressure regulating device for F50 installation specifications adapted to lightweight requirements. The overall assembly structure from top to bottom includes: anti-fouling cover 1, test iron plate 2, pressure ring 3, heavy ion microporous membrane 4, valve cover 5, inner sealing ring 6, valve body 7, outer sealing ring 8, hollow guide rod 9, return spring 10, moisture barrier valve plate 11, moisture absorption column 12, and rear cover 13.

[0093] Key parameters for this embodiment: Heavy ion microporous membrane 4: PET substrate heavy ion track etching membrane, pore size 2μm, porosity 15%; uniform stress on the membrane surface, explosion-proof opening pressure deviation ≤±5%, protection level up to IP68, IPX9K.

[0094] Moisture-barrier valve plate 11: 8mm outer diameter, 0.8mm overall thickness, made of platinum-cured high-tear-resistance silicone rubber with a hardness of Shore A48; a Φ0.4mm through-hole anti-adhesion micropore 111 is opened in the center, extending into several radial slits 112 to form a multi-valve structure, with a single slit length of 3.5mm and an R0.2mm crack-resistant fillet at the outer end of the slit; an annular thinning groove 113 is provided around the micropore at the root of the slit, with a groove depth of 0.3mm and an inner diameter of 2.0mm, reducing the effective bending thickness at the valve root to 0.3mm, forming a continuous flexible hinge. The valve plate is installed in the upper part of the inner cavity of the hollow guide rod 9, and has the functions of moisture barrier, opening and closing, and axial buffering.

[0095] One-piece molded moisture-absorbing column 12: outer diameter 8mm, inner diameter 4mm, height 7.2mm, concentricity of inner and outer circles ≤0.05mm, overall porosity 45%; raw materials by mass: 78 parts D50 3μm low-chlorine 4A molecular sieve, 20 parts o-cresol formaldehyde modified bisphenol F epoxy resin, 28 parts potassium carbonate pore-forming agent, 2 parts KH560 silane coupling agent; potassium carbonate adopts a two-stage particle size distribution of 50μm and 150μm, with a mass ratio of 4:6, and is ground through a 200-mesh sieve before mixing; residual chloride ion content of finished product <10ppm.

[0096] Hollow guide rod 9: made of high-temperature resistant engineering plastic, with an inner cavity diameter of 8.4mm and a single-sided gap of 0.2mm with the moisture-absorbing column 12; the width of the sealing lip on the outer periphery of the middle part is 1.2mm, which fits tightly with the inner wall of the valve body 7 under normal conditions; the overall weight is reduced by about 40% compared with the aluminum alloy guide rod.

[0097] Performance indicators: Explosion-proof opening pressure 4±0.2kPa; positive pressure air permeability ≥320ml / min@2.5kPa; the overall product weight is lighter and the manufacturing cost is lower.

[0098] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0099] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 application.

[0100] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0101] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0102] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0103] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0104] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Since these modifications and variations fall within the scope of the claims and their equivalents, this application also intends to include these modifications and variations.

[0105] The above description describes specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A sealed cavity explosion-proof device with a built-in integrated breathing unit, characterized in that, From top to bottom, it includes: anti-fouling cover, heavy ion microporous membrane assembly, valve cover, valve body, hollow guide rod, return spring, moisture barrier valve plate, moisture absorption column, and rear cover; The hollow guide rod is slidably disposed in the central guide cavity of the valve body, and the return spring is disposed between the bottom of the hollow guide rod and the valve body to provide sealing pre-tightening force and return spring force; The moisture-blocking valve plate and the integrally formed moisture-absorbing column are embedded in the inner cavity of the hollow guide rod from top to bottom. The rear cover is sealed at the bottom of the inner cavity of the hollow guide rod, and a vent hole is reserved in the center to connect to the inside of the sealed cavity. The device is equipped with an independent central micro-breathing branch and an external main pressure relief branch.

2. The explosion-proof device with a sealed cavity and built-in integrated breathing unit according to claim 1, characterized in that, The heavy ion microporous membrane is a track-etched membrane.

3. The explosion-proof device with a sealed cavity and built-in integrated breathing unit according to claim 1, characterized in that, The moisture barrier valve plate includes a circular silicone body; the center of the circular silicone body has a through anti-adhesion micropore; several radial cuts extend evenly outward from the anti-adhesion micropore; the circular silicone body also has an annular thinning groove surrounding the anti-adhesion micropore, the depth of the annular thinning groove being 0.2 to 0.5 mm.

4. The explosion-proof device with a sealed cavity and built-in integrated breathing unit according to claim 3, characterized in that, The outer diameter of the circular silicone body is 6 to 10 mm, and the thickness is 0.6 to 1.0 mm; the pore size of the anti-adhesion micropores is 0.3 to 0.5 mm; the length of a single radial cut is 2.5 to 5.0 mm; the annular thinning groove is located at the root of the radial cut, and the inner diameter of the groove is 1.5 to 3.0 mm.

5. The explosion-proof device with a sealed cavity and built-in integrated breathing unit according to claim 3, characterized in that, The circular silicone body is made of platinum vulcanized silicone rubber with a hardness of Shore A40 to 55 degrees; the moisture barrier valve is sandwiched between the top surface of the hollow guide rod cavity and the integrally formed moisture-absorbing column.

6. The explosion-proof device with a sealed cavity and built-in integrated breathing unit according to claim 1, characterized in that, The moisture-absorbing column is a hollow cylindrical rigid integral structure. The whole is a continuous porous skeleton formed by integral molding and curing of 4A molecular sieve functional powder and modified epoxy resin binder. The interior forms uniform and interconnected multi-level micron-level air-permeable channels with a porosity of 30% to 50%.

7. The explosion-proof device with a sealed cavity and built-in integrated breathing unit according to claim 6, characterized in that, The porous framework is composed of the following raw materials: 70 to 80 parts of low-chlorine ultrafine 4A molecular sieve, 18 to 25 parts of modified epoxy resin, 20 to 35 parts of potassium carbonate pore-forming agent, and 1 to 2 parts of silane coupling agent; the residual chloride ion content of the system is less than 10 ppm.

8. The explosion-proof device with a sealed cavity and built-in integrated breathing unit according to claim 6, characterized in that, The potassium carbonate pore-forming agent has a two-stage particle size distribution of 50μm and 150μm, with a mass ratio of 4:6; after being washed and eluted with water, it forms a continuous and interconnected macroporous channel.

9. The explosion-proof device with a sealed cavity and built-in integrated breathing unit according to claim 6, characterized in that, The modified epoxy resin is o-cresol-modified bisphenol F type epoxy resin, combined with a latent curing agent; the silane coupling agent is KH560 type.

10. The explosion-proof device with a sealed cavity and built-in integrated breathing unit according to claim 1, characterized in that, The hollow guide rod is a stepped hollow structure with a flange, with a central vent and guide post at the top, an outer sealing lip in the middle, and an installation cavity at the bottom.

11. The explosion-proof device with a sealed cavity and built-in integrated breathing unit according to claim 1, characterized in that, The device controls the opening and closing of the main pressure relief branch on the periphery through the axial displacement of the hollow guide rod, and controls the opening and closing of the central micro-breathing branch through the elastic deformation of the moisture-proof valve plate.

12. A method for preparing a sealed cavity explosion-proof device with a built-in integrated breathing unit, characterized in that, Includes the following steps: Step 1: Ingredient mixing: After the low-chlorine ultrafine 4A molecular sieve is activated at high temperature and cooled under nitrogen protection, it is mixed with potassium carbonate pore-forming agent, modified epoxy resin, latent curing agent and silane coupling agent in a vacuum mixing equipment according to the mass ratio. After vacuum degassing, a uniform paste-like premix is ​​obtained. Step 2: Warm pressing: The premixed material is quantitatively injected into the molding mold with a central mandrel. After the mold is preheated, the molding process is carried out by segmented pressurization and venting. After demolding, a hollow cylindrical green body is obtained. Step 3: Step-by-step curing: The green body is placed in a programmed heating equipment and the resin cross-linking and curing are gradually completed by using a multi-stage step-by-step heating and heat preservation method. After slow cooling in the furnace, a rigid porous skeleton is formed. Step 4: Eluting and Gradient Drying: The solidified porous framework is placed in deionized water, and the soluble potassium carbonate pore-forming agent is eluted and removed using a negative pressure immersion circulation process to form continuous and interconnected multi-level channels; after elution, the internal moisture is removed using a gradient temperature drying process to obtain the finished moisture-absorbing column. Step 5: Finished product inspection and post-processing: The finished products are tested in sequence for size, porosity, air permeability resistance, dust fall amount and chloride ion residue. Qualified products are vacuum-packed for moisture protection after dust removal treatment.

13. The method for preparing a sealed cavity explosion-proof device with a built-in integrated breathing unit according to claim 12, characterized in that, In step 1, the molecular sieve activation conditions are: oven heating at 380℃ for 2 hours, with nitrogen protection throughout the cooling process; a double planetary vacuum stirrer is used, with a mixing time of 10 to 15 minutes, followed by vacuum degassing for at least 20 minutes; cooling water is used during the mixing process to control the material temperature to ≤40℃; the potassium carbonate pore-forming agent needs to be ground through a 200-mesh sieve before mixing; in step 2, the inner wall of the mold is coated with a Teflon non-stick coating, and the surface of the mandrel is mirror-polished; in step 4, the gradient drying process is: first drying at 60℃ for 2 hours, then heating to 100℃ for 2 hours, and finally heating to 120℃ for 1 hour.

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