Tubular multichannel barrier explosion-proof structural body and preparation method thereof

Abstract

The invention relates to a tubular multi-channel barrier explosion-proof structural body, belongs to the technical field of barrier explosion prevention, and solves the problems that an explosion-proof structural body in the prior art is large in filling density, poor in fluidity in the filling process, needs to be further improved in flame-retardant and explosion-proof performance and structural strength, and poor in product process stability. The invention provides a tubular multi-channel blocking anti-explosion structural body, the anti-explosion structural body comprises an outer tubular body 1 and an inner tubular body 3 which are coaxially arranged from outside to inside, the outer tubular body 1 is a circular truncated cone-shaped tubular body or a regular prismatic table-shaped tubular body, and the inner tubular body 3 is a circular truncated cone-shaped tubular body or a regular prismatic table-shaped tubular body; the small end face of the outer tubular body 1 is flush with the large end face of the inner tubular body 3, and the large end face of the outer tubular body 1 is flush with the small end face of the inner tubular body 3. The explosion-proof structural body is high in structural strength, reasonable in layout, capable of effectively restraining flame propagation and enabling explosion pressure waves to be sharply attenuated, and excellent in explosion-proof performance; the flame retardant property is not lower than V-0 level, the compression strength is not lower than 15MPa, and the filling density can be as low as 55.87 kg / m < 3 >.

Description

Technical Field

[0001] The present invention relates to the technical field of explosion isolation and prevention, and in particular to a tubular multi-channel explosion isolation and prevention structure body and a preparation method thereof. Background Art

[0002] The explosion isolation and prevention technology is a technology that can effectively prevent the explosion of inflammable and explosive gaseous and liquid hazardous chemicals caused by accidental accidents (such as static electricity, welding, shooting, collision, incorrect operation, etc.) during storage and transportation. Installing explosion isolation and prevention materials with explosion-proof functions in containers can fundamentally solve the problems of combustion, explosion and other dangers that occur during the storage, transportation and use of inflammable and explosive liquid and gaseous hazardous chemicals.

[0003] The explosion isolation and prevention material is specifically a honeycomb structure, which can divide the interior of the storage, transportation and use containers of inflammable and explosive liquid and gaseous hazardous chemicals into several "small chambers" or "cavities". These "small chambers" or "cavities" can effectively contain the spread of flames and sharply attenuate the explosion pressure wave; at the same time, this honeycomb structure material has a high surface efficiency per unit volume, so it has good heat absorption, can quickly absorb the heat released by combustion, reduce the temperature after the combustion reaction, reduce the expansion degree of the reaction gas, and the pressure value in the container does not increase much, so that the combustion speed cannot reach the explosion limit speed, thus achieving the purpose of explosion prevention.

[0004] Currently, the existing explosion isolation and prevention materials generally have defects such as insufficient structural strength, poor flame retardancy and explosion prevention performance, poor product stability, and poor corrosion resistance. Problems such as collapse and slag falling are likely to occur, and they cannot meet the requirements of flame retardancy and explosion prevention under special conditions. Summary of the Invention

[0005] In view of the above analysis, the present invention aims to provide a tubular multi-channel explosion isolation and prevention structure body to solve at least one of the problems of the existing explosion isolation and prevention materials, such as large filling density, poor fluidity during the filling process, insufficient structural strength, poor flame retardancy and explosion prevention performance, poor product stability, poor corrosion resistance, easy collapse, slag falling, etc.

[0006] The object of the present invention is mainly achieved by the following technical solutions:

[0007] The present invention provides a tubular multi-channel explosion isolation and prevention structure body, characterized in that the explosion isolation and prevention structure body includes an outer tubular body 1 and an inner tubular body 3 coaxially arranged from outside to inside. The outer tubular body 1 is a frustum-shaped tubular body or a regular prism frustum-shaped tubular body, and the inner tubular body 3 is a frustum-shaped tubular body or a regular prism frustum-shaped tubular body;

[0008] The small end face of the outer tubular body 1 is flush with the large end face of the inner tubular body 3, and the large end face of the outer tubular body 1 is flush with the small end face of the inner tubular body 3;

[0009] The inner surface of the outer tubular body 1 and the outer surface of the inner tubular body 3 are connected by trapezoidal support pieces 2. The trapezoidal support pieces 2 are arranged radially along the explosion-proof structure member and are evenly distributed in a circumferential direction; the trapezoidal support pieces 2 are connected to the generatrices and / or side edges of the outer tubular body 1 and the inner tubular body 3;

[0010] A circular or polygonal connecting piece 4 is arranged on the small end surface of the inner tubular body 3;

[0011] The explosion-proof structure body is divided into a plurality of identical divided areas by the trapezoidal support pieces 2, and through holes are provided in the outer tubular body 1 and the inner tubular body 3 corresponding to each divided area.

[0012] Specifically, when both the outer tubular body 1 and the inner tubular body 3 are regular frustum structures, the number of sides of the two is equal, and the connecting line of the corresponding frustum vertices is located on the same radial line.

[0013] Preferably, a weight reduction notch is provided on the upper edge and / or the lower edge of the trapezoidal support piece 2.

[0014] Preferably, the area ratio of the through holes is 70-80%, the number of the through holes ≥ 1, and the shapes of the through holes are circular, elliptical, triangular, trapezoidal, square, rectangular or other polygons.

[0015] Optionally, the inner tubular body 3 is a multi-layer structure.

[0016] Specifically, the included angle between the generatrix or the side edge of the outer tubular body 1 and the inner tubular body 3 and the axis is 0.5-30°.

[0017] Specifically, the explosion-proof structure body is made of an antistatic and flame-retardant modified resin; the modified resin contains a matrix resin, a flame-retardant filler, a conductive filler and an additive; the content of each component is calculated by mass parts: 4-8 parts of the matrix resin, 1-3 parts of the flame-retardant filler, 0.5-2 parts of the conductive filler, and 0.5-1 part of the additive.

[0018] Specifically, the matrix resin is one or more of resins such as polyethylene, polypropylene, polyvinyl chloride, polyamide, polycarbonate, polyester, polyphenylene sulfide, polystyrene, etc.;

[0019] The conductive filler is one or more of carbon fiber, carbon nanotube, graphite, graphene, carbon black;

[0020] The flame-retardant filler is one of a phosphorus-based flame retardant, a nitrogen-based flame retardant or a nitrogen-phosphorus-based synergistic flame retardant;

[0021] The additive is a lubricant and / or an internal release agent.

[0022] Specifically, the explosion-proof structure body is made by an injection molding process.

[0023] The present invention also provides a method for preparing the explosion-proof structure, which specifically comprises the following steps:

[0024] Step 1: Mix the ingredients according to the preset formula by a mixer, prepare the mixture system into mixture particles by single-screw or twin-screw extrusion, and then transfer them to an injection molding machine for molding;

[0025] Step 2: prepare an injection mold, inject the molten mixture system into the forming mold through an injection molding machine, and obtain the finished explosion-proof structure after the forming mold is kept warm, pressurized, cooled, and demolded.

[0026] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0027] 1. The explosion-proof structure provided by the present invention forms a plurality of stable small compartments with a certain barrier effect through an outer tubular body, an inner tubular body, and a trapezoidal support body. These small compartments can effectively curb the spread of flames and sharply attenuate the explosion pressure wave; at the same time, this material has a high surface efficiency per unit volume and good heat absorption, and can quickly absorb the heat released by combustion, so that the temperature after the combustion reaction is reduced, the expansion degree of the reaction gas is reduced, and the pressure value in the container is not increased much, so that the combustion speed does not reach the limit speed of the explosion, thereby achieving the purpose of explosion prevention.

[0028] Among them, it is particularly worth emphasizing that the outer tubular body is a truncated cone tubular body or a regular prism-shaped tubular body, and the inner tubular body is a truncated cone tubular body or a regular prism-shaped tubular body; the small end face of the outer tubular body is flush with the large end face of the inner tubular body, and the large end face of the outer tubular body is flush with the small end face of the inner tubular body; that is, the large and small end faces of the outer tubular body and the inner tubular body are arranged in opposite directions (see Figure 1 ). The above arrangement enables the small compartment to form a trapezoidal structure in the axial section. Compared with the small compartments with the same axial width in the prior art, the small compartments with the trapezoidal structure have greatly improved structural strength and stability, can withstand stronger explosion shock waves, and have a better explosion-proof effect.

[0029] Secondly, because the outer tubular body adopts a truncated cone or a regular prism shape, it is more stable in the container under normal assembly conditions and is not prone to shaking and collision, which not only extends the life of the explosion-proof structural parts, but also protects the inner wall of the container.

[0030] The explosion-proof structure also adds a circular or polygonal connecting piece on the small end face of the inner tubular body. The connecting piece can further improve the overall strength of the structure on the one hand, and also provide axial partition on the other hand, which is beneficial to improve the explosion-proof performance.

[0031] In addition, the above-mentioned connecting piece can be used as an injection port of the injection molding process, so that the structural part can meet the requirements of the injection molding process. When the above-mentioned structural part is prepared by modified resin and injection molding process, the entire structural part can have excellent flame retardant and explosion-proof properties and a smoother surface, and the product stability is greatly improved.

[0032] 2. The explosion-proof structure has a low filling density and has little effect on the flow of liquid in the container (good fluidity during the filling process). The explosion-proof structure is provided with through holes on the outer tubular body and the inner tubular body, and the proportion of the through hole area is limited, so that the strength of the explosion-proof structure and the flame retardant and explosion-proof performance are ensured, while significantly reducing the impact on the flow of the fluid medium. Tests show that the impact on the flow velocity of the fluid medium does not exceed 0.5%.

[0033] On the other hand, the opening of the through hole also effectively reduces the weight and volume of the explosion-proof structure, avoids occupying too much internal space in the container, and helps to increase the filling density of the explosion-proof structure. The filling density of the explosion-proof structure can be as low as 55.87kg / m 3 .

[0034] In addition, during the filling process of the explosion-proof structure, there is no dislocation or intersection between the units, and the fluidity is better. There are intersections between the units of the explosion-proof structure in the prior art (for example, various auxiliary support structures are set in the prior art to improve the structural strength, resulting in the existence of "beams" and other structures in the internal space of the small compartment; or the small compartment is not connected in the axial direction). The crossed units will cause the filling density to increase and affect the flow of the fluid medium. The filling density of the explosion-proof structure can be as low as 55.87kg / m 3 .

[0035] 3. The explosion-proof structure is a whole, and the angles and dimensions (mainly thickness) of each structural part are designed to meet the needs of actual production. Therefore, the explosion-proof structure can be prepared by injection molding;

[0036] Injection molding can accurately control the weight of each product. The direct weight difference between independent products can be controlled within 1%. At the same time, the consistency of product dimensions is much higher than that of extrusion molding. In addition, the injection molding process has better adaptability to materials and can be applied to more types of resins for processing.

[0037] For the explosion-proof structural parts, when flame-retardant and antistatic modified resins are used for preparation through injection molding, the best comprehensive explosion-proof performance can be obtained, and the product stability / consistency is excellent. It is particularly preferred that when the modified resins of the present invention are used for preparation, the flame-retardant and explosion-proof performance is better.

[0038] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the following specification, and some advantages can be made obvious from the specification, or understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained from the content specifically pointed out in the specification and the drawings. Description of the Drawings

[0039] The drawings are only for the purpose of showing specific embodiments, and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference signs represent the same components.

[0040] Figure 1 Schematic perspective view of an embodiment of a tubular multi-channel barrier explosion-proof structure (Embodiment 1);

[0041] Figure 2 Top view of an embodiment of a tubular multi-channel barrier explosion-proof structure (Embodiment 1);

[0042] Figure 3 Front view of an embodiment of a tubular multi-channel barrier explosion-proof structure (Embodiment 1);

[0043] Figure 4 Cross-sectional view of an embodiment of a tubular multi-channel barrier explosion-proof structure (Embodiment 1);

[0044] Figure 5 Schematic perspective view of an embodiment of a tubular multi-channel barrier explosion-proof structure (Embodiment 3).

[0045] Reference Signs:

[0046] 1, outer tubular body; 2, trapezoidal support piece; 3, inner tubular body; 4, connecting piece. Detailed Description of the Embodiments

[0047] The following will specifically describe the preferred embodiments of the present invention in conjunction with the drawings. The drawings form a part of this application and are used together with the embodiments of the present invention to explain the principles of the present invention, and are not used to limit the scope of the present invention.

[0048] The present invention provides a tubular multi-channel barrier explosion-proof structure. The explosion-proof structure includes an outer tubular body and an inner tubular body that are coaxially arranged from outside to inside. The outer tubular body is a frustum of a cone or a regular frustum structure, and the inner tubular body is a frustum of a cone or a regular frustum structure;

[0049] The small end face of the outer tubular body is flush with the large end face of the inner tubular body, and the large end face of the outer tubular body is flush with the small end face of the inner tubular body;

[0050] The inner surface of the outer tubular body and the outer surface of the inner tubular body are connected by trapezoidal support pieces, which are arranged radially along the explosion-proof structural member and are evenly distributed in a circumferential direction; the trapezoidal support pieces are connected to the generatrix and / or side edges of the outer tubular body and the inner tubular body;

[0051] The explosion-proof structure provided by the present invention forms stable and multiple small compartments with a certain blocking effect through the outer tubular body, the inner tubular body, and the trapezoidal support body. These small compartments can effectively contain the spread of flames, causing the explosion pressure wave to decay sharply; at the same time, this material has a high surface efficiency per unit volume and good heat absorption properties, and can quickly absorb the heat released by combustion, reducing the temperature after the combustion reaction, shrinking the expansion degree of the reaction gas, and not increasing the pressure value in the container much, so that the combustion speed cannot reach the explosion limit speed, thus achieving the purpose of explosion protection.

[0052] Among them, it is particularly worth emphasizing that the outer tubular body is a frustum-shaped tubular body or a regular pyramid frustum-shaped tubular body, and the inner tubular body is a frustum-shaped tubular body or a regular pyramid frustum-shaped tubular body; the small end face of the outer tubular body is flush with the large end face of the inner tubular body, and the large end face of the outer tubular body is flush with the small end face of the inner tubular body; that is to say, the outer tubular body and the inner tubular body are arranged in the opposite direction (see Figure 1 ). The above setting makes the small compartments form a trapezoidal structure in the axial section. The trapezoidal-structured small compartments have greatly improved structural strength and stability compared with the small compartments with the same width up and down in the prior art, can withstand stronger explosion shock waves, and have a more excellent explosion-proof effect.

[0053] Secondly, due to the frustum-shaped or regular pyramid frustum-shaped design of the outer tubular body, under normal assembly conditions, it is more stable in the container, not easy to shake and collide, which not only extends the service life of the explosion-proof structural member but also protects the inner wall of the container.

[0054] The small end face of the inner tubular body is provided with circular or polygonal connecting pieces. The explosion-proof structure also adds circular or polygonal connecting pieces to the small end face of the inner tubular body. On the one hand, the above connecting pieces can further improve the overall strength of the structural member, and on the other hand, they also provide an axial partition, which is beneficial to improving the explosion-proof performance.

[0055] In addition, the above connecting pieces can be used as injection ports for the injection molding process, so that the structural member can meet the requirements of the injection molding process. When the above structural member is prepared by using a modified resin and the injection molding process, the entire structural member can have excellent flame retardant and explosion-proof properties and a smoother surface, and the product stability is greatly improved.

[0056] Preferably, through holes are formed in the connecting piece, and the through holes are arranged in accordance with the specific injection molding process requirements (injection port design) and the shape of the inner tubular body; the through holes help to reduce the influence of the structural member on the fluid flow in the container, and are beneficial to reducing the volume and weight of the explosion-proof structure.

[0057] Specifically, when both the outer tubular body and the inner tubular body are regular frustums, the number of sides of the two is equal, and the connecting lines of the corresponding frustum vertices are located on the same diameter line. When both the outer tubular body and the inner tubular body are regular frustums, in order to ensure the uniformity of the entire structural member and achieve isotropy as much as possible, the number of sides of the outer tubular body and the inner tubular body should be equal and the connecting lines of the corresponding frustum vertices should be located on the same diameter line; the above setting method helps to improve the overall stability of the structure. It should be noted that the structural strength and uniformity of a regular frustum with an even number of sides are better than those of a regular frustum with an odd number of sides.

[0058] Preferably, the regular frustum is a regular frustum with 2, 4, 6, 8, 10, or 12 sides, and a regular frustum with 6 or 8 sides is particularly preferred; mainly to ensure excellent explosion-proof performance without significantly increasing the weight of a single structure.

[0059] Similarly, when one of the outer tubular body or the inner tubular body is a regular frustum (that is, only one of the two is a regular frustum structure and the other is a frustum of a cone structure), a regular frustum structure with an even number of sides is still preferred, and a regular frustum with 6 or 8 sides is particularly preferred.

[0060] Optionally, weight-reducing notches are provided on the upper edge and / or the lower edge of the trapezoidal support piece. The setting of the weight-reducing notches can increase the internal void space of the explosion-proof structure, improve the explosion-proof effect, and help to reduce the volume and weight of the entire explosion-proof structure, further saving costs; in principle, the total area ratio of the weight-reducing notches does not exceed 10% of the area of the trapezoidal support piece, otherwise it may affect the overall structural strength and explosion-proof performance.

[0061] Specifically, the explosion-proof structure is divided into a plurality of identical divided areas by the trapezoidal support piece, and through holes are formed in the outer tubular body and the inner tubular body corresponding to each divided area. The setting of the above through holes makes the entire structural member radially connected, and the circumferential direction is blocked / divided by the trapezoidal support piece; radial connection is to prevent the explosion-proof structure from affecting the flow rate of the fluid medium / fuel and thus affecting the refueling or unloading speed; circumferential division is to ensure the explosion-proof effect of the explosion-proof structure and has a blocking and partitioning effect on combustion waves and shock waves.

[0062] Preferably, the proportion of the area of the through holes is 60-80%, such as 60%, 65%, 70%, 75%, 80%. If it is too large, it will affect the structural strength of the entire structure; if it is too small, it will affect the fuel flow efficiency and explosion-proof effect, and will also increase the weight of a single structure, thereby increasing the weight per unit volume of the product. The number of through holes in a single divided area ≥ 1, and the shape of the through holes is circular, oval, triangular, trapezoidal, square, rectangular or other polygons.

[0063] Particularly preferably, the proportion of the area of the through holes in both the outer tubular body and the inner tubular body is 75% and the number of through holes in a single divided area is 1, that is, there is 1 through hole in the outer tubular body and 1 through hole in the inner tubular body.

[0064] Optionally, the inner tubular body is a multi-layer structure, the shapes of the layers of the multi-layer structure match and are coaxial with each other, the large-diameter sides and the small-diameter sides of two adjacent inner tubular bodies are arranged at the same end, and the trapezoidal support pieces extend radially inward and are connected to each layer structure of the inner tubular body, so that the inner tubular body and the outer tubular body of the multi-layer structure form an integral body.

[0065] It should be noted that when there is a regular frustum-shaped structure in the multi-layer structure of the inner tubular body and there are more than 2 regular frustum-shaped structures in the explosion-proof structure (such as several layers in the outer tubular body + inner tubular body; or several layers in the inner tubular body); the number of side edges of each regular frustum should be equal to ensure that the trapezoidal support pieces can be connected radially along the side edges.

[0066] It should be emphasized that when the inner tubular body is a multi-layer structure, through holes are provided at corresponding positions in each divided area of each layer structure.

[0067] Specifically, the multi-layer structure is 2-3 layers, preferably 2 layers. Too many layers will not significantly improve the structural strength and flame-retardant explosion-proof performance, and will significantly increase the weight and volume of the explosion-proof structure.

[0068] Specifically, the angle between the generatrix or side edge of the outer tubular body and the inner tubular body and the axis is 0.5-30°, such as 0.5°, 1°, 2°, 5°, 10°, 15°, 20°, 25°, 30°. The outer tubular body and the inner tubular body of the above shapes are helpful to improve the structural strength of the structural member, especially the structural strength of the internal small compartments, and are beneficial to the flow and filling of the modified resin in the injection molding process. The slopes of the inner and outer tubular bodies can be the same or different, but the inner side of the small-diameter end face of the outer tubular body is not connected to the outer side of the large-diameter end face of the inner tubular body, that is, the inner diameter of the small-diameter end face of the outer tubular body is greater than the outer diameter of the large-diameter end face of the inner tubular body.

[0069] Particularly preferably, the slopes of the inner and outer tubular bodies are the same, which is more conducive to processing and forming, making the symmetry of the forming die higher, and the life and stability are both higher.

[0070] Specifically, the thickness of each component of the explosion-proof structure is uniform, ranging from 0.1 to 2.0 mm, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0 mm. If the thickness is too thin, it is not conducive to forming (especially in the injection molding process), and the structural strength of the product is low. If the thickness is too thick, the weight of the product per unit volume is too large. Preferably, the thickness is 0.4 mm.

[0071] Specifically, the inner diameter of the large end face of the outer tubular body is 20 - 500 mm, such as 20, 30, 33, 50, 80, 100, 200, 300, 400, 500 mm. This range is suitable for the installation port sizes of containers such as small fuel tanks, pipelines, and large oil tanks; the height is 3 - 300 mm, such as 3, 10, 20, 30, 50, 80, 100, 200, 300 mm. The height comprehensively considers the installation port size of the container and the convenience of installation.

[0072] Preferably, the large end of the outer tubular body is preferably 33 mm, and the height is 30 mm. This size is determined based on the size of the refueling port of portable oil drums on the market, which is convenient for installation and takes into account the explosion-proof effect.

[0073] Specifically, the size of the inner tubular body is determined according to the size of the outer tubular body, as long as the inner diameter of the small-diameter end face of the outer tubular body is greater than the outer diameter of the large-diameter end face of the inner tubular body; the height of the inner tubular body is the same as that of the outer tubular body.

[0074] Specifically, the explosion-proof structure is made by the injection molding process. Injection molding can accurately control the weight of each product. The direct weight difference between independent products can be controlled within 1%, and at the same time, the consistency of the product's external dimensions is much higher than that of extrusion molding; moreover, the injection molding process has better adaptability to materials and can be applied to more types of resins for processing;

[0075] For the explosion-proof structural part, when it is prepared by the injection molding process using flame-retardant and antistatic modified resin, the best comprehensive explosion-proof performance can be obtained, and the product stability / consistency is excellent.

[0076] Specifically, the explosion-proof structure is made of antistatic and flame-retardant modified resin.

[0077] Specifically, the modified resin contains matrix resin, flame-retardant filler, conductive filler, and additive; the content of each component is calculated by mass: matrix resin 4 - 8 parts, flame-retardant filler 1 - 3 parts, conductive filler 0.5 - 2 parts, additive 0.5 - 1 part.

[0078] The functions and content determination basis of each component are as follows:

[0079] Matrix resin: The matrix resin is the main material for preparing the explosion-proof structure, and its properties are directly related to the compatibility with the contact medium and the structural strength of the product. Whether the matrix resin is added too much or too little will affect the realization of the flame retardancy, conductivity and other functions of the modified material. If too much matrix resin is added (i.e., too little of other components are added), the modified function cannot be realized; if too little is added, the product performance improvement is not obvious and the product cost increases significantly (the cost of other components is relatively high).

[0080] Conductive filler: It improves the conductivity of the modified resin. Since the matrix resin is usually an insulating material, and the contact medium in the application scenario, such as hydrocarbon fuel, is a saturated aliphatic hydrocarbon, and static electricity accumulation is likely to occur due to intermolecular friction. Therefore, the explosion-proof filler should have the ability to conduct electricity or static electricity, which can prevent the accumulation of static charges from triggering static discharge phenomena and improve the safety of the contact medium itself. If too much conductive filler is added, the product cost will increase and the forming ability of the modified material will be affected, the fluidity will decrease, resulting in a decrease in the melt index and the product cannot be formed; if too little is added, the conductivity cannot be achieved.

[0081] Flame retardant filler: It improves the flame retardancy of the modified resin. Since the matrix resin is usually a non-flame-retardant material, and the contact media in the application scenario are mostly flammable and explosive hydrocarbon fuels and liquid hazardous chemicals (such as alcohols, ketones, ethers, aromatic hydrocarbons, etc.), which are prone to catch fire and burn. Therefore, it is necessary to ensure that the explosion-proof structure itself does not burn and avoid the combustion or explosion of the contact medium caused by the combustion of the explosion-proof structure itself. If too much flame retardant filler is added, the product cost will increase and the forming ability of the modified material will be affected, the fluidity will decrease, resulting in a decrease in the melt index and the product cannot be formed; if too little is added, the flame retardancy cannot be achieved.

[0082] Additive: The additive is a lubricant and / or a demolding agent. The lubricant plays a role in lubricating the matrix resin, enabling it to improve the crystallization ability of the matrix resin molecules during the processing process and retaining its bulk properties to the greatest extent; the function of the demolding agent is because the explosion-proof structure of the present invention is formed by thin-wall injection molding, and an injection mold is required during the molding process, and the product demolding process is relatively difficult. Therefore, by adding a demolding agent to the matrix resin, the demolding ability of the product is improved, the demolding effect is improved, which helps to stabilize production and improve the finished product rate. Appropriate addition helps to improve the product performance, and excessive addition will lead to a decrease in the product performance.

[0083] Synergistic effect: The above-mentioned components are added according to the product performance requirements, and a flame retardant filler system and a conductive filler system that conform to the matrix resin system are adopted to ensure that the explosion-proof structure has excellent flame retardancy, low volume resistivity and good fluidity, and is suitable for the injection molding process.

[0084] Specifically, the matrix resin is one or more of polyethylene, polypropylene, polyvinyl chloride, polyamide, polycarbonate, polyester, polyphenylene sulfide, polystyrene and the like; all of the above resins are thermoplastic resins, which can be processed by injection molding process, and can achieve functional requirements by flame retardant and conductive modification.

[0085] Because the explosion-proof structure is an explosion-proof safety product for hazardous chemicals, there are many types of flammable and explosive hazardous chemicals, and different types of hazardous chemicals, such as alcohol, require resins such as polyethylene or polypropylene with low polarity as the matrix material, so that the matrix resin and alcohol hazardous chemicals have good compatibility; and for hydrocarbon fuels, such as gasoline and diesel, resins with high polarity are required as the matrix resin, such as polyamide, polyphenylene sulfide, etc.

[0086] The conductive filler is one or more of carbon fiber, carbon nanotube, graphite, graphene, and carbon black;

[0087] The flame retardant filler is one of a phosphorus flame retardant, a nitrogen flame retardant or a nitrogen-phosphorus synergistic flame retardant. Common flame retardants of the above types can meet the implementation needs. Exemplarily, the flame retardant filler is triphenyl phosphate or melamine phosphate.

[0088] The additive is a lubricant and / or an internal mold release agent, which is mainly used to increase the demoulding ability of the base resin during the modification process, reduce the risk of being unable to demould, and improve the product qualification rate. Common commercial products can meet the implementation needs. For example, the additive is pentaerythritol stearate or calcium stearate.

[0089] Specifically, the volume resistivity of the modified resin is not more than 1.0×10 10 Ω.cm, the combustion grade is not less than UL94V-1, and the melt index is not less than 10g / 10min. Barrier explosion-proof structures are used in hydrocarbon fuels and hazardous chemicals. These materials often cause explosion accidents during transportation, use, transfer and storage due to friction, electric shock, etc. of their own molecules (such as fuel is hydrocarbon, non-polar materials, friction generates static electricity), which leads to charge concentration and discharge. Therefore, barrier explosion-proof materials are required to have anti-static ability. Relevant product standards, such as GJB 8455 "General Technical Specifications for Barrier Explosion-proof Materials for Oil Tank Filling", require that the volume resistivity of such materials shall not exceed 1.0×10 10 Ω.cm.

[0090] It is worth mentioning that this is because the product adopts the injection molding process, and the melt index is too low, which means that the fluidity of the modified resin material in the high-temperature molten state is worse, and thin-wall injection molding is more difficult, or even impossible to form, which affects the product molding quality and molding efficiency.

[0091] Specifically, the volume resistivity of the explosion-proof structural member provided by the present invention is ≤6.3×108 Ω·cm, the amount of debris in vibration test ≤ 1.0 mg / L, the flame retardancy is not lower than V-0 level, the compressive strength is not lower than 15 MPa, the melt index is not lower than 47 g / 10 min, and no secondary explosion occurs in the explosion-proof test.

[0092] The present invention also provides a preparation method of the explosion-proof structure body, which specifically includes the following steps:

[0093] Step 1: Weigh materials according to a preset formula, mix them evenly through a mixer, prepare the mixture system into mixture particles by single-screw or twin-screw extrusion, and then transfer them into an injection molding machine for molding;

[0094] Step 2: Prepare an injection mold, inject the molten mixture system into the forming mold through an injection molding machine, and obtain the finished explosion-proof structure body after heat preservation, pressure holding, cooling, and demolding of the forming mold.

[0095] Example 1

[0096] This example provides a tubular multi-channel barrier explosion-proof structure body (as shown in Figure 1 ), the explosion-proof structure body includes an outer tubular body and an inner tubular body coaxially arranged from outside to inside. The outer tubular body is frustum-shaped, and the inner tubular body is frustum-shaped;

[0097] The small end face of the outer tubular body is flush with the large end face of the inner tubular body, and the large end face of the outer tubular body is flush with the small end face of the inner tubular body;

[0098] The inner surface of the outer tubular body and the outer surface of the inner tubular body are connected by trapezoidal support pieces. The trapezoidal support pieces are arranged radially along the explosion-proof structure member and are evenly distributed in a circumferential direction; the trapezoidal support pieces are connected to the generatrices of the outer tubular body and the inner tubular body; there are a total of 8 trapezoidal support pieces;

[0099] The small end face of the inner tubular body is provided with a circular connecting piece. The connecting piece is provided with 8 trapezoidal through holes (chamfered) evenly distributed in a circumferential direction and corresponding to the divided areas / small compartments. The area ratio of the through holes is 60% of the area of the connecting piece;

[0100] Trapezoidal weight-reducing notches are arranged on the upper and lower edges of the trapezoidal support pieces, and the area of a single notch accounts for 5% of the total area of the trapezoidal support piece;

[0101] The explosion-proof structure body is divided into 8 completely identical divided areas by the trapezoidal support pieces. Through holes are opened in the outer tubular body and the inner tubular body corresponding to each divided area;

[0102] The area ratio of the through holes is 75%, the number of through holes is 1, and the shape of the through holes is trapezoidal (chamfered);

[0103] The thickness of each component of the explosion-proof structure is 0.4 mm;

[0104] The inner diameter of the large end face of the outer tubular body is 33 mm, the inner diameter of the small end face is 30 mm, and the height is 30 mm; the inner diameter of the large end face of the inner tubular body is 18 mm, the inner diameter of the small end face is 15 mm, and the height is 30 mm.

[0105] The explosion-proof structure is made of a modified resin. The composition of the modified resin is as follows by mass: the matrix resin is polycarbonate, the flame retardant filler is triphenyl phosphate, the conductive filler is carbon nanotubes, and the additive is pentaerythritol stearate. The content of each component is 70%:15%:8%:7% by mass percentage.

[0106] The explosion-proof structure of this embodiment is obtained by an injection molding process.

[0107] Example 2

[0108] The difference between this embodiment and Example 1 is that the explosion-proof structure is made of a modified resin. The composition of the modified resin is as follows by mass: the matrix resin is polypropylene, the flame retardant is melamine phosphate, the conductive filler is carbon fiber, and the additive is calcium stearate. The content of each component is 60%:20%:14%:6% by mass percentage.

[0109] Example 3

[0110] The difference between this embodiment and Example 1 is that the product structure is a three-layer tubular body design. The outer tubular body is a single-layer frustum structure, and the inner tubular body is a two-layer frustum structure. (As Figure 5 shown)

[0111] Among them, the inner diameter of the large end face of the outer tubular body is 38 mm, the inner diameter of the small end face is 34 mm, and the height is 34 mm; the inner diameter of the large end face of the middle tubular body is 27 mm, the inner diameter of the small end face is 23 mm, and the height is 34 mm; the inner diameter of the large end face of the inner tubular body is 17 mm, the inner diameter of the small end face is 15 mm, and the height is 34 mm.

[0112] According to JT / T 1046 "Technical Requirements for Blocking and Explosion Protection of Fuel Tanks and Liquid Fuel Transport Tanks of Road Transport Vehicles", GJB8455 "General Technical Specifications for Blocking and Explosion Protection Materials for Fuel Tanks and Oil Tanks Filling", and AQT 3001 "Technical Requirements for Blocking and Explosion Protection of Oil (Gas) Storage Tanks in Gas Stations (Gas Stations)", all three standards stipulate that the volume resistivity of the blocking and explosion protection materials shall not be greater than 1.0×10 10 Ω·cm, the flame retardant level shall not be lower than V-1 level, the amount of debris after the vibration test shall not exceed 1.3 mg / L and 1.0 mg / L respectively, and the filling density shall not exceed 80 kg / m 3, no secondary explosion occurs during the static explosion test. Table 1 shows the relevant test results of Examples 1-3 of the present invention, and the test results meet the requirements of relevant standards.

[0113] Table 1 Performance Test Results of Examples 1-3

[0114]

[0115] The volume resistivity of the explosion-proof structural member provided by the present invention is ≤6.3×10 8 Ω·cm, the debris amount in the vibration test is ≤1.0 mg / L, the flame retardant performance is not lower than V-0 level, and the filling density is ≤76 kg / m 3 , the compressive strength is not lower than 15 MPa, the melt index is not lower than 47 g / 10 min, and no secondary explosion occurs during the explosion-proof test.

[0116] It should be noted that in Example 3, the inner tubular body of the multi-layer structure sacrifices the performance of filling density, but helps to improve the strength and stability of the overall structure. Moreover, due to the division of more "small compartments", the flame retardant and explosion-proof performance is further improved; since the test conditions of the static explosion test and the flame retardant level are limited by relevant standards, the advantages of the multi-layer structure cannot be intuitively shown. The test results are all without secondary explosion and the flame retardant level is V-0 (the highest level). This is hereby explained.

[0117] In fact, according to the above test results, it can also be seen that the relevant performance of the structure in Example 1 can fully meet the requirements of explosion-proof and flame retardant, and the indicators such as filling density, flame retardant performance and compressive strength are significantly improved.

[0118] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A tubular multi-channel barrier explosion-proof structure, characterized in that The explosion-proof structure includes an outer tubular body (1) and an inner tubular body (3) which are coaxially arranged from outside to inside. The outer tubular body (1) is a frustum-shaped tubular body or a regular prism frustum-shaped tubular body, and the inner tubular body (3) is a frustum-shaped tubular body or a regular prism frustum-shaped tubular body; The small end face of the outer tubular body (1) is flush with the large end face of the inner tubular body (3), and the large end face of the outer tubular body (1) is flush with the small end face of the inner tubular body (3); The inner surface of the outer tubular body (1) and the outer surface of the inner tubular body (3) are connected by trapezoidal support pieces (2). The trapezoidal support pieces (2) are arranged along the radial direction of the explosion-proof structure member and are evenly distributed along the circumference; The trapezoidal support pieces (2) are connected to the generatrices and / or side edges of the outer tubular body (1) and the inner tubular body (3); A circular or polygonal connecting piece (4) is arranged on the small end face of the inner tubular body (3); The explosion-proof structure is divided into a plurality of identical divided areas by the trapezoidal support pieces (2), and through holes are provided in the corresponding outer tubular body and inner tubular body of each divided area.

2. The explosion-proof structure according to claim 1, characterized in that, When both the outer tubular body (1) and the inner tubular body (3) are regular prism frustum-shaped tubular bodies, the number of sides of the two is equal, and the connecting line of the corresponding prism vertices is located on the same radial line.

3. The explosion-proof structure according to claim 1, characterized in that, A weight reduction notch is provided on the upper edge and / or the lower edge of the trapezoidal support piece (2).

4. The explosion-proof structure according to claim 1, characterized in that, The area ratio of the through holes is 70-80%, the number of through holes ≥ 1, and the shape of the through holes is circular, elliptical, triangular, trapezoidal, square, rectangular or other polygons.

5. The explosion-proof structure according to claim 1, characterized in that The inner tubular body (3) is a multi-layer structure.

6. The explosion-proof structure according to claim 1, wherein, The included angle between the generatrix or side edge of the outer tubular body (1) and the inner tubular body (3) and the axis is 0.5-30°.

7. The explosion-proof structure according to claim 1, wherein The explosion-proof structure is made of an antistatic and flame-retardant modified resin; The modified resin contains a matrix resin, a flame retardant filler, a conductive filler and an additive; The content of each component is calculated by mass: 4-8 parts of matrix resin, 1-3 parts of flame retardant filler, 0.5-2 parts of conductive filler, and 0.5-1 part of additive.

8. The explosion-proof structure according to claim 7, wherein, The matrix resin is one or more of resins such as polyethylene, polypropylene, polyvinyl chloride, polyamide, polycarbonate, polyester, polyphenylene sulfide, polystyrene, etc.; The conductive filler is one or more of carbon fiber, carbon nanotube, graphite, graphene, carbon black; The flame retardant filler is one of a phosphorus-based flame retardant, a nitrogen-based flame retardant or a nitrogen-phosphorus-based synergistic flame retardant; The additive is a lubricant and / or an internal mold release agent.

9. The explosion-proof structure according to claim 7 or 8, characterized in that The explosion-proof structure is made by an injection molding process.

10. A method for preparing the explosion-proof structure according to any one of claims 1 to 9, characterized in that, Specifically, it includes the following steps: Step 1: Weigh according to a preset formula, mix evenly through a mixer, prepare the mixture system into mixture particles by single-screw or twin-screw extrusion, and then transfer them into an injection molding machine for molding; Step 2: Prepare an injection mold, inject the molten mixture system into the forming mold through an injection molding machine, and obtain the finished explosion-proof structure after heat preservation, pressure holding, cooling and demolding of the forming mold.

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