Novel environment-friendly firecracker

Abstract

The invention discloses two novel environment-friendly firecrackers, and belongs to the technical field of firework manufacturing. The first scheme is based on direct heating and dynamic pressure sealing and comprises an outer shell, an inner shell and an internal solid peroxide oxygen source block. The core of the device is that a dynamic pressure sealing mechanism composed of a slidable baffle and a top soft sealing gasket is arranged, sealing is formed through pre-tightening of a lead at the beginning, pressure pushes the baffle to move upwards to press the sealing gasket after gas is generated through reaction, dynamic sealing enhanced along with the pressure is formed, and therefore the pressure is efficiently accumulated to achieve explosion. The second scheme is based on low-temperature indirect and uniform heating, the core is that the heat conductor embedded in the concave position of the inner shell is heated through a low-temperature lead, indirect and uniform heating of the solid oxygen source block is achieved, and decomposition and gas production of the solid oxygen source block are triggered. According to the two schemes, a blocky solid oxygen source is adopted, the problems of pollution and safety of a traditional firecracker are fundamentally solved, the defects that a powder environment-friendly firecracker is prone to being affected with damp and poor in reliability are overcome, and the firecracker is environmentally friendly, safe, high in reliability and real and traditional in experience feeling.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pyrotechnic manufacturing, and in particular to a novel environmentally friendly firecracker based on thermal decomposition of peroxide, and more particularly to two parallel technical solutions with different thermal triggering mechanisms. BACKGROUND

[0002] Firecrackers are traditional celebration items, and their traditional formula is usually based on black powder. Black powder poses significant safety risks during production and ignition, and produces a large amount of sulfur oxides, nitrogen oxides, carbon particles, and metal particles, which seriously harm air quality and human health.

[0003] To address the above problems, some environmentally friendly firecracker alternatives have appeared on the market, such as electronic firecrackers and cold light fireworks. However, electronic firecrackers cannot simulate the real explosion sound, shock wave, and chemical fire, and the experience is poor; cold light fireworks have visual effects, but their use is often restricted, and some chemical compositions may still produce harmful gases. In addition, some environmentally friendly firecrackers based on powdered chemicals have reliability problems such as moisture susceptibility, component separation, and high rate of duds.

[0004] Therefore, there is an urgent need in the art for an innovative solution that can fundamentally solve pollution problems, has excellent moisture resistance and reliability, and can perfectly reproduce the traditional firecracker sound, light, and shock wave experience. SUMMARY

[0005] (I) Invention Objectives The present application aims to provide two novel environmentally friendly firecracker solutions to overcome the shortcomings of the prior art through different but parallel technical paths. Both solutions aim to achieve sulfur and phosphorus pollution-free, high moisture resistance, high reliability, high safety, and real traditional firecracker experience.

[0006] (II) Technical Solutions To achieve the above invention objectives, the present application adopts the following two preferred technical solutions: Solution One: Environmentally friendly firecracker based on direct heating and dynamic pressure sealing The core of this solution is to achieve explosion effect through thermal decomposition of solid peroxide oxygen source combined with a unique dynamic sealing structure to accumulate pressure. Specifically, it includes: Shell structure: including an external support shell and an inner shell arranged inside it. The inner shell is made of biodegradable material (such as PLA, PHA) with excellent water vapor barrier properties, and a closed reaction chamber is formed inside it.

[0007] Reactant: a solid oxygen source block contained in the reaction chamber, whose composition is solid peroxide, such as sodium percarbonate, calcium peroxide, etc.

[0008] Ignition system: comprising a lead wire, which penetrates through the inner shell and extends to contact or adjacent to the solid oxygen source block, for initiating thermal decomposition of the solid oxygen source block.

[0009] Dynamic pressure sealing system: comprising a movable baffle plate arranged at the protrusion of the inner cavity, and a soft sealing pad arranged on the inner wall of the top of the inner shell. The lead wire penetrates through the baffle plate and is fixed to the bottom of the reaction cavity by its own tension or pre-tightening of the baffle plate, forming an initial seal. The system is configured to maintain the reaction cavity closed at the initial stage of the reaction; when the reaction generates gas pressure, the baffle plate is pushed to move upward, making it press against the soft sealing pad, forming a dynamic seal that is strengthened with the increase of pressure, thereby achieving efficient accumulation of pressure.

[0010] In a preferred embodiment, the ignition system further comprises a solid combustible agent (such as a metal wire) in close thermal contact with the lead wire. The solid combustible agent has the dual function of efficiently conducting heat from the lead wire to the reactants and participating in the vigorous oxidation reaction as the main fuel, which can significantly enhance the reaction intensity and visual effect.

[0011] Scheme II: Environmentally friendly firecrackers based on low-temperature indirect uniform heating The core of this scheme is to trigger the decomposition of the solid oxygen source through low-temperature, indirect heating, and to avoid local overheating by controlling the heat transfer path. Specifically, it includes: Shell structure: comprising an external supporting shell and an inner shell arranged inside it. The inner shell is made of biodegradable material (such as PHA) with pressure resistance and water vapor barrier property, and forms a reaction cavity inside.

[0012] Reactant: a solid oxygen source block contained in the reaction cavity, which is composed of solid peroxide, preferably urea peroxide with a lower decomposition temperature.

[0013] Low-temperature indirect heating system: comprising a low-temperature lead wire with a combustion temperature below 300℃, and a heat conductor in close contact with the low-temperature lead wire and arranged in the inner cavity of the inner shell. The heat conductor is used to conduct the heat generated by the low-temperature lead wire to the inner wall of the inner shell, and then heat the solid oxygen source block inside. The material and structure of the heat conductor can be selected according to the required heating rate and uniformity, for example, a metal tube can be used to achieve uniform heating, or a material with weak thermal conductivity can be used to achieve gentle gradient heating.

[0014] In a preferred embodiment, a pH adjuster can also be added to the reaction cavity to neutralize the acidic or basic by-products that may be produced during the reaction, so that the pH value of the aqueous solution of the solid residue after the reaction is stable between 5 and 9, further improving the environmental performance.

[0015] (Three) beneficial effects Compared with the prior art, the present application has the following beneficial effects: 1. Two technical paths achieve extreme environmental protection: The reaction products of scheme one are mainly environmentally friendly salts and metal oxides; Scheme two can effectively inhibit the generation of by-products such as ammonia gas generated by the decomposition of urea peroxide through indirect and / or uniform heating mechanism. Both of them avoid pollution of sulfur and phosphorus compounds and toxic gases from the root. The optional pH adjuster can further ensure the environmental friendliness of the residues.

[0016] 2. High reliability and moisture resistance: Both schemes use solid reaction substances in block or die-cast form, which have good physical stability and fundamentally avoid the problems of moisture absorption and component separation of powders. The dynamic sealing of scheme one ensures efficient pressure accumulation, and the controlled heating of scheme two ensures the completion of the reaction, which together makes the misfire rate very low.

[0017] 3. Excellent safety: The mechanical sensitivity of the reactants in scheme one is much lower than that of traditional black powder; Scheme two uses low-temperature and indirect heating to avoid the risk of high-temperature detonation from the source. Both of them significantly reduce the safety risks in the production, transportation and storage processes.

[0018] 4. Real traditional experience and adjustability: Scheme one can produce loud explosion sound and strong shock wave through dynamic sealing to accumulate high pressure; Scheme two can flexibly adjust the power and sound through the charge amount, shell strength and heating method, which together perfectly simulates the sensory experience of traditional firecrackers.

[0019] 5. Little dust pollution: Both schemes use block structure from the raw material form, only a few large dust particles are generated during production and use, which completely eliminates the pollution of inhalable particulate matter.

[0020] 6. Design flexibility: The solid combustible agent in scheme one is an optional component, which broadens the design ideas; The selection and configuration method of the heat conductor in scheme two is diverse, which can be optimized according to the thermal sensitivity of different peroxides, and has wide applicability. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the cross-sectional structure schematic diagram of the embodiment one (environment-friendly firecracker based on direct heating and dynamic pressure sealing) of the present application.

[0022] In the figure, 1. outer shell 2. inner shell 3. solid oxygen source block 4. lead 5. solid combustible agent 6. baffle 7. soft sealing pad.

[0023] Among them, the solid combustible agent (5) is shown by a dashed line, indicating that it is an optional component.

[0024] Figure 2 is the cross-sectional structure schematic diagram of the embodiment two (environment-friendly firecracker based on low-temperature indirect and uniform heating) of the present application.

[0025] Figure 3 Fig. 1 is a perspective view of the present application. Figure 2 Fig. 2 is a top view of the present application.

[0026] Fig. 3 is a cross-sectional view of the present application. DETAILED DESCRIPTION

[0027] The present application is further described in conjunction with the accompanying drawings and examples, but not limited to the scope of protection of the present application. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application. Example 1

[0028] In combination with Figure 1 The present example provides an environmentally friendly firecracker based on direct heating and dynamic pressure sealing.

[0029] The outer shell 1 is made of red renewable paperboard, and the top is pre-made with a mechanical weak line that is easy to break by indentation.

[0030] The inner shell 2 is made of polylactic acid (PLA) by injection molding, and is fixedly nested inside the outer shell 1 to form a closed reaction cavity.

[0031] The solid oxygen source block 3 is a cylinder of sodium percarbonate powder pressed by a tablet press and placed at the bottom of the reaction cavity.

[0032] The ignition system includes a lead wire 4. As a preferred solution of the present example, it also includes a thin iron wire 5 wrapped in a ring around the outer periphery of the lead wire 4 as a solid combustible agent. The lead wire 4 passes through a reserved hole on the inner shell 2 and is inclined at an angle of about 45 degrees through a movable baffle 6 made of PHA plastic. The movable baffle 6 is pre-tensioned and fixed at the protruding part of the inner cavity by the self-tension of the lead wire 4, forming an initial seal.

[0033] The soft sealing gasket 7 is made of elastic sponge rubber material and is fixed to the inner wall of the top of the inner shell 2 by adhesive.

[0034] During ignition, the user ignites the lead wire 4. The flame and heat directly act on the sodium percarbonate block 3 and simultaneously heat the solid combustible agent iron wire 5 to a red-hot state. This triggers the rapid thermal decomposition of the sodium percarbonate block 3 to release oxygen, which reacts violently with the red-hot iron wire 5 to produce a large amount of heat and gas. The gas pressure pushes the movable baffle 6 to move upward and tightly presses the soft sealing gasket 7 at the top to form a dynamically enhanced seal. The pressure in the cavity rapidly accumulates, eventually causing the outer shell 1 to break from the pre-made weak line at the top, producing an explosion effect.

[0035] It can be understood that, in the pursuit of the ultimate visual effect, also can omit solid combustible agent 5, only rely on the direct ignition of the fuse 4, sodium percarbonate decomposition gas explosion. Example 2:

[0036] In combination Figure 2 The embodiment provides an environment-friendly firecracker based on low-temperature indirect uniform heating.

[0037] The outer shell 3 and the inner shell 4 are integrally formed by blow molding process of biodegradable polyhydroxyalkanoate (PHA), the wall thickness of the inner shell 4 is slightly thinner than that of the outer shell 3, and a blasting weak area is preset at the top.

[0038] The solid oxygen source block 3 is a block body formed by die casting of urea peroxide.

[0039] The low-temperature indirect uniform heating system comprises an aluminum thin-walled heat conduction pipe 5 connected to the inner recess of the inner shell 4, and a low-temperature safety fuse 1 wound in a ring shape and having a combustion temperature of about 250 DEG C.

[0040] When the firecracker is fired, the low-temperature fuse 1 is ignited. The heat generated by the low-temperature fuse 1 is rapidly conducted to the aluminum heat conduction pipe 5, which uniformly heats the wall surface of the entire inner shell 4. The heat is conducted to the urea peroxide block 2 in the interior, so that the urea peroxide block 2 is entirely decomposed, a large amount of gas is generated, the pressure in the cavity is suddenly increased, and finally the shell is blasted from the weak part. Due to the uniform heating, local overheating is avoided, and the generation of by-products is effectively inhibited.

Claims

1. An environmentally friendly firecracker based on dynamic pressure sealing, characterized in that, include: One outer shell (1); An inner shell (2) is disposed inside the outer shell (1), and a sealed reaction chamber is formed inside the inner shell (2); A solid oxygen source block (3) is placed in the reaction chamber, and its composition is a pressed solid peroxide. An ignition component includes a lead wire (4) that passes through the inner shell (2) and extends to contact the solid oxygen source block (3); A dynamic pressure sealing mechanism includes a baffle (6) that can slide vertically along the inner wall of the reaction chamber, and a soft sealing gasket (7) fixedly disposed on the top inner wall of the inner shell (2); wherein, the lead wire (4) passes through the baffle (6) and presses the baffle (6) against the protruding structure at the bottom of the reaction chamber by its own tension to form an initial seal; The dynamic pressure sealing mechanism is configured such that when the gas pressure in the reaction chamber increases, it pushes the baffle (6) to slide upward and presses it against the soft sealing gasket (7) to form a dynamic reinforced seal.

2. The environmentally friendly firecracker according to claim 1, characterized in that, The ignition component further includes a solid combustible agent (5) that is in close thermal contact with the lead wire (4), wherein the solid combustible agent (5) is at least one of metal wire, carbon fiber or combustible polymer wire.

3. The environmentally friendly firecracker according to claim 1, characterized in that, The soft sealing gasket (7) is made of sponge, rubber, silicone or biodegradable elastic polymer, and the baffle (6) is made of biodegradable plastic, rigid cardboard or plant fiber pressed parts.

4. An environmentally friendly firecracker based on indirect uniform heating, characterized in that, include: One outer shell (3); An inner shell (4) is disposed inside the outer shell (3), and a reaction chamber is formed inside the inner shell (4); A solid oxygen source block (2) is contained in the reaction chamber, and its composition is solid peroxide; A heating system includes a low-temperature lead (1) with a combustion temperature below 300°C and a heat conductor (5); wherein, the top of the inner shell (4) is provided with a recess, the heat conductor (5) is embedded in the recess and closely fits the outer wall of the inner shell (4); the low-temperature lead (1) is in contact with the outer surface of the heat conductor (5); the heat conductor (5) is configured to uniformly conduct the heat generated by the low-temperature lead (1) to the wall of the inner shell (4).

5. The environmentally friendly firecracker according to claim 4, characterized in that, The heat conductor (5) is a metal tube or metal foil and is attached around the outer wall of the inner shell (4).

6. The environmentally friendly firecracker according to claim 1 or 4, characterized in that, The solid oxygen source block is one or more combinations of sodium percarbonate, urea peroxide, calcium peroxide, or magnesium peroxide.

7. The environmentally friendly firecracker according to claim 1 or 4, characterized in that, The reaction chamber is also equipped with a pH adjuster, which is at least one of a solid organic acid, a solid inorganic acid, or a salt thereof.

8. The environmentally friendly firecracker according to claim 7, characterized in that, The pH adjuster is citric acid, zinc oxide, calcium carbonate, or dihydrogen phosphate.

9. The environmentally friendly firecracker according to claim 1 or 4, characterized in that, The outer shell and / or inner shell are prefabricated with mechanically weak lines or weak areas that are prone to breakage.

10. The environmentally friendly firecracker according to claim 1 or 4, characterized in that, The inner shell is made of a biodegradable material, such as polyhydroxyalkanoate, polylactic acid, modified starch-based composite material, or biodegradable polyester.

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