Method for preventing ablation and leakage of solid oxygen generator and solid oxygen generator

Abstract

The present invention belongs to the technical field of chemical oxygen production, and provides a method for preventing ablation and leakage of a solid oxygen generator and a solid oxygen generator. The method for preventing ablation and leakage of a solid oxygen generator comprises: extending the length of the thermal insulation material along the axial direction of the solid oxygen column, and adding thermal insulation fillers in the extended thermal insulation material. The present invention changes the flow direction of the molten material at the end of the solid oxygen column from the original horizontal to the vertical direction by appropriately extending the thermal insulation material in the axial direction of the solid oxygen column; at the same time, due to the addition of thermal insulation fillers in the vertical direction, the temperature of the molten material will gradually decrease during the flow process until it solidifies, thereby completely avoiding the contact between the high-temperature molten material and the metal shell, and effectively preventing the ablation and leakage of the solid oxygen generator. Compared with several methods proposed in the prior art, it is simple to operate and low in cost.

Description

Technical Field

[0001] The invention relates to the technical field of chemical oxygen production, and in particular to a method for preventing ablation and leakage of a solid oxygen generator and a solid oxygen generator. Background Art

[0002] Solid oxygen generators are used as a respiratory oxygen source for standing or emergency personnel in confined spaces, and are widely used in civil aviation, space station oxygen, submarines, firefighting, plateaus, battlefields, mine rescue, etc. The working process of a solid oxygen generator is that chlorate-based solid oxygen columns release oxygen through thermal decomposition under the action of a catalyst. The basic chemical reaction equation of typical sodium chlorate solid oxygen is:

[0003] 2NaClO3→2NaCl+3O2+ΔHr

[0004] The energy released by the chemical reaction is ΔHr = -14731Cal / mol = -61.7kJ / mol. It can be seen that the solid oxygen generator releases a large amount of heat during use, and the surface temperature can reach up to 300°C. In particular, when the heat inside the solid oxygen generator accumulates to a certain extent, under the coupling of high temperature and high heat (ignition source), high-purity oxygen (combustible material), and metal shell (combustible material), the solid oxygen generator is prone to ablation and perforation, and violent combustion, leading to serious safety accidents and even major deaths. Therefore, how to prevent ablation and leakage of solid oxygen generators is an important part of ensuring the safety of personnel use.

[0005] CN203807161U uses phase change materials (such as paraffin) to absorb the heat generated by the thermal decomposition of solid oxygen medicine columns. CN106698354A uses a heat exchanger to reduce the temperature of solid oxygen medicine columns. CN107867675A uses an inner and outer ring structure, the inner ring is a medicine column containing a small amount of metal fuel, and the main components of the outer ring are sodium chlorate and a catalyst in a suitable ratio, which does not contain metal fuel. The outer ring medicine is designed to catalytically decompose by the heat transferred from the inner core medicine to reduce excessive heat accumulation. CN212403460 U reduces the reaction rate by adding retarders such as sodium chromate and barium chromate to the medicine column and arranging phase change materials such as HDPE hot melt adhesive powder, LDPE hot melt adhesive powder or PES copolyester hot melt adhesive powder outside the medicine column. CN217773033U proposes to dissipate heat by combining spiral pipes and cooling water. CN116750720A adds heat absorbents such as Al(OH)3 and Mg(OH)2 to the solid oxygen powder column to reduce the heat generated by the oxygen-producing powder core. CN112960651A adds an inner shell structure made of high-melting-point copper metal between the heat-insulating material layer close to the powder column and the outer shell of the solid oxygen generator, and adds copper wire to the outer wall of the inner shell for binding and reinforcement, using the method of high-melting-point metal heat resistance and increasing the overall strength of the structure to delay the contact between the internal heat and the outer shell.

[0006] In general, the existing technology alleviates the problem of energy accumulation by adopting phase change materials, adding retardants and heat absorbers, increasing heat dissipation structures, changing the structure of the grain, adding high melting point metal inner shells, and external bundling to avoid ablation leakage accidents. However, the use of phase change materials, heat dissipation structures, and the addition of high melting point metal inner shells lead to increased weight and volume, and the addition of retardants and heat absorbers makes the formula components more complex, the mixing degree decreases, and the fluctuation range of the combustion process increases. The manufacturing process of the special-shaped grain structure and the external bundling structure is complicated and costly. Therefore, it is very important to find a simple way to prevent ablation leakage of solid oxygen generators. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a method for preventing ablation and leakage of a solid oxygen generator and a solid oxygen generator.

[0008] Solid oxygen generators, especially those with large oxygen release (such as 500L and 1000L), are prone to ablation, perforation and leakage during use, which may cause fires. The reason is largely related to the thermal insulation structure of the solid oxygen column. Usually, the solid oxygen column is wrapped with thermal insulation material and then loaded into a metal shell. The thermal insulation material can prevent heat loss on the one hand, and help reduce the surface temperature of the solid oxygen generator on the other hand. During the wrapping operation, the length of the thermal insulation material is the same as that of the solid oxygen column in the axial direction of the solid oxygen column. In addition, a certain volume and weight of impurity gas absorption material (such as hopcalite, soda lime, calcium lime, etc.) is set below the end of the solid oxygen column to eliminate toxic and harmful CO, CO2, Cl2, etc. At the same time, in order to prevent the end of the solid oxygen column from adversely affecting the impurity gas absorption material during high-temperature decomposition, a certain thickness of porous thermal insulation material needs to be added between the two, and the size and shape of the porous thermal insulation material are highly consistent with the inner size and shape of the metal shell. From this structure, there is an obvious gap between the bottom of the solid oxygen column wrapped with insulation material and the porous insulation material below it. Under high heat accumulation, the molten oxygen generator will flow directly to the inner surface of the metal shell through the gap. At this time, the three elements of combustion are present, namely, ignition source (high temperature), combustion-supporting material (high-purity oxygen), and combustible material (metal shell). Since the ignition point of stainless steel is usually between 550-750℃, which is close to the internal temperature of the solid oxygen generator, it is entirely possible that the metal shell will be instantly ablated and perforated under the action of high-purity oxygen.

[0009] Based on this, in a first aspect, the present invention provides a method for preventing ablation leakage of a solid oxygen generator, comprising: extending the length of a thermal insulation material along the axial direction of the solid oxygen charge column, and adding a thermal insulation filler in the extended thermal insulation material.

[0010] The present invention appropriately extends the heat insulation material in the axial direction of the solid oxygen powder column, so that the flow direction of the molten material at the end of the solid oxygen powder column will be changed from the original horizontal direction to the current vertical direction. At the same time, due to the addition of several layers of heat insulation fillers in the vertical direction, the temperature of the molten material will gradually decrease during the flow process until it solidifies, thereby completely avoiding the contact between the high-temperature molten material and the metal shell, and effectively preventing the ablation and leakage of the solid oxygen generator.

[0011] Preferably, the extended length of the heat insulation material accounts for 10%-15% of the length of the solid oxygen column. If the extended length is too long, the structural strength of the product in the axial length will be reduced, making the product easy to damage and not conducive to use. If it is too short, the effect of preventing ablation leakage is poor.

[0012] In some embodiments of the present invention, the thermal insulation material is a porous thermal insulation material, such as one or more of glass fiber, asbestos, and rock wool.

[0013] In some embodiments of the present invention, the heat insulating filler is provided in 2-5 layers. The heat insulating filler is filled according to the shape of the inner cavity of the extended heat insulating material, and is provided in 2-5 layers according to the extended length, preferably evenly distributed in each layer. More preferably, 3-4 layers are provided.

[0014] Preferably, the thermal insulation filler is one or more of expanded perlite, hollow polyamide fiber, porous ceramic clay, and ceramic microbeads.

[0015] In a second aspect, the present invention provides a solid oxygen generator, comprising a solid oxygen charge and a thermal insulation material wrapped around the outer surface of the solid oxygen charge, wherein the length of the thermal insulation material is greater than the length of the solid oxygen charge, and a thermal insulation filler is additionally provided inside the portion of the thermal insulation material that exceeds the solid oxygen charge.

[0016] Preferably, the length of the thermal insulation material is 10%-15% longer than the length of the solid oxygen powder column.

[0017] In some embodiments of the present invention, the thermal insulation material is a porous thermal insulation material, such as one or more of glass fiber, asbestos, and rock wool.

[0018] In some embodiments of the present invention, the thermal insulation filler is one or more of expanded perlite, hollow polyamide fiber, porous ceramic clay, and ceramic microbeads.

[0019] In some embodiments of the present invention, the heat insulating filler is provided in 2-5 layers. The heat insulating filler is filled according to the shape of the inner cavity of the extended heat insulating material, and is provided in 2-5 layers according to the extended length, preferably evenly distributed in each layer. More preferably, 3-4 layers are provided.

[0020] In some embodiments of the present invention, the composition of the solid oxygen column is, by weight percentage, 90.0-95.0% sodium chlorate, 3-5.5% potassium perchlorate, 1-4% catalyst, and 0.5-5% binder.

[0021] In the above technical solution, the catalyst and the binder can be selected from conventional catalysts and binders in the field of solid oxygen powder columns. Preferably, the catalyst is cobalt oxide; the binder is ceramic fiber, especially in large solid oxygen generators.

[0022] The preparation method of the solid oxygen drug column in the present invention is carried out according to the conventional method in the art.

[0023] The present invention provides a method and a solid oxygen generator for preventing ablation and leakage of a solid oxygen generator. By appropriately extending the heat insulation material in the axial direction of the solid oxygen powder column, the flow direction of the molten material at the end of the solid oxygen powder column is changed from the original horizontal direction to the vertical direction; at the same time, due to the addition of heat insulation fillers in the vertical direction, the temperature of the molten material will gradually decrease during the flow process until it solidifies, thereby completely avoiding the contact between the high-temperature molten material and the metal shell, and effectively preventing the ablation and leakage of the solid oxygen generator. Compared with several methods proposed in the prior art, the operation is simple and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the oxygen release rate curve of the solid oxygen generator based on the new thermal insulation structure design in the embodiment of the present invention.

[0025] Figure 2 It is a comparison diagram of the effects of the method of the present invention (right figure) and the conventional method (left figure). DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0028] Example 1

[0029] This embodiment provides a solid oxygen generator, and the manufacturing method thereof is as follows:

[0030] The formula of the solid oxygen powder column used is: 91.0% sodium chlorate, 3.5% potassium perchlorate, 2.5% catalyst cobalt oxide, 3.0% ceramic fiber, divided into 8 sections, each section is 200 grams, the total weight is 1600 grams, the designed oxygen supply is about 530L, and the total length of the powder column is 440mm. Sodium chlorate, potassium perchlorate, cobalt oxide, and ceramic fiber are weighed respectively according to the proportion required by the formula. The weighed raw materials are put into a mixer for mechanical stirring and mixing, and the mixing time is 1 hour. After mixing, pour the mixture into a cylindrical mold. After loading, remove the tablets, press and form with 10 tons of pressure, and the pressure holding time is 5 minutes. After demolding, 8 Φ45mm×55mm cylindrical solid oxygen powder columns with exactly the same components, shapes, and sizes are obtained. Eight solid oxygen charge columns are stacked up, wrapped with a 500mm wide (440mm+60mm, 440mm is the total length of the charge column, and 60mm is the extended length) porous heat insulating material, and four layers of heat insulating fillers are added in the extended cavity (the cross section of each layer is perpendicular to the axial direction of the solid oxygen charge column). They are then loaded into a metal shell to make a corresponding solid oxygen generator, which is started by mechanical ignition.

[0031] The results show that the oxygen release rate of the solid oxygen generator continues to increase during the entire working process, with an initial oxygen release rate of about 5L / min and a maximum of more than 40L / min at the end, indicating that the combustion rate at the end of the solid oxygen column in the solid oxygen generator is the fastest, the temperature is out of control, and the risk of ablation leakage is high. However, due to the addition of a 60mm long porous thermal insulation material along the axial direction of the solid oxygen column to form a cavity, and the insertion of a thermal insulation material layer with a diameter of 45mm and a total thickness of 60mm (single piece thickness 15mm) in the cavity, ablation perforation leakage accidents are effectively prevented. The designed oxygen supply is about 530L, the actual oxygen supply is 528.7L, and the oxygen release time is about 25min. The specific oxygen release rate records are shown in Tables 1-1, 1-2, 1-3, 1-4, 1-5 and Figure 1 After the oxygen is released and the solid oxygen generator is disassembled after cooling, it can be clearly seen that the outer edge of a small section of the 60mm thermal insulation material layer inserted later is contaminated by the flowing molten material (such as Figure 2 As shown in the middle right figure, the outer edge of the inserted insulation material is contaminated with black molten material). On the contrary, the solid oxygen generator that does not extend the insulation material wrapped around the solid oxygen column and add insulation material will lead to ablation, leakage and combustion accidents (such as Figure 2 The method of the present invention is simple and effective.

[0032] Table 1-1

[0033] Time / h:mm:ss Instantaneous oxygen release rate / L / min Total oxygen release / L 0:00:00 O O 0:00:10 11.405 0.833 O:00:20 8.226 2.429 O:00:30 7.832 3.666 0:00:40 4.97 4.633 0:00:50 7.329 5.75 0:01:00 1O.559 7.044 0:01:10 11.104 9.031 0:01:20 9.98 10.817 0:01:30 9.071 12.363 0:01:40 8.456 13.854 0:01:50 6.088 15.185 0∶02∶00 6.907 16.173 O:02:10 8.115 17.325 0:02∶20 11.024 18.992 0:02：30 10.168 20.897 0∶02∶40 7.225 22.388 0:02:50 12.503 23.73 0∶03:00 10.709 25.884 0:03:10 9.023 27.575 0∶03:20 7.242 28.959 0:03:30 5.089 30.077 0:03:40 5.989 31.022 0:03∶50 9.97 32.417 0:04:00 10.183 34.031 0:04∶10 12.086 35.862 0:04∶20 16.017 38.132 0:04:30 15.381 40.711 0:04:40 16.036 43.432 0:04:50 12.946 46.085 0:05:00 11.315 47.889 O∶05∶10 13.206 50.082 0:05:20 17.24 52.38

[0034] Table 1-2

[0035] Time / h:mm:ss Instantaneous oxygen release rate / L / min Total oxygen release / L 0:05:30 13.723 55.071 O:05:40 18.953 57.782 0:05:50 22.357 61.136 0:06:00 22.571 65.324 0:06∶10 23.455 69.184 O:06∶20 23.682 73.282 O:06∶30 21.952 77.082 0:06:40 23.304 80.672 0:06:50 22.529 84.594 O:07:00 19.561 88.363 0:07:1O 18.581 91.151 O:07:20 17.966 94.203 O:07:30 18.629 97.563 O:07:40 17.211 100.297 O:07:50 17.604 103.499 O:08:00 18.356 106.134 0:08:1O 19.789 109.666 0:08:20 21.166 113.112 O:08:30 21.051 116.603 O:08:40 22.128 120.146 0:08:50 23.64 124.463 O:09:00 22.575 127.888 O:09:1O 22.191 131.617 0:09∶20 18.46 134.945 0:09∶30 18.078 138.053 O:09:40 16.988 141.186 O:09:50 18.21 143.868 O∶10∶00 19.13 147.295 0:10∶10 18.724 150.494 0:10:20 16.137 153.423 O:1O:30 14.81 155.991 O∶10∶40 13.963 158.282 0:10:50 14.485 160.618

[0036] Table 1-3

[0037] Time / h:mm:ss Instantaneous oxygen release rate / L / min Total oxygen release / L 0:11:00 17.691 163.297 O:11:10 18.607 166.449 0:11:20 18.612 169.65 O:11:30 18.317 172.798 0:11:40 17.593 175.781 O:11:50 17.322 178.975 0:12:00 21.32 181.86 0:12:10 16.498 185.439 0:12:20 19.01 188.041 0:12:30 20.055 191.705 0:12:40 15.615 194.674 0:12:50 19.477 197.29 0:13:00 18.401 200.846 0:13:10 16.591 203.69 0:13:20 16.002 206.506 0:13:3O 15.272 209.082 0:13:40 14.187 211.791 0:13:50 16.41 213.922 0:14:00 19.519 217.33 0:14:10 17.373 220.238 0∶14∶20 17.297 223.053 O:14:30 16.862 226.239 0:14:40 16.942 228.757 0:14:50 17.536 231.853 0∶15∶00 17.294 234.635 O∶15∶10 22.639 237.932 0:15:20 22.852 241.962 0:1530 21.251 245.57 0:15:40 23.715 249.336 0:15:50 25.532 253.53 0:16:00 23.985 257.699 O∶16∶10 23.064 261.652 0:16:20 21.48 265.349

[0038] Table 1-4

[0039] Time / h:mm:ss Instantaneous oxygen release rate / L / min Total oxygen release / L 0:16:30 27.625 269.282 O:16:40 26.874 274.197 0∶16∶50 21.752 277.858 0:17:00 21.465 281.731 0∶17∶10 22.885 284.93 0:17:20 26.108 289.424 0:17∶30 26.508 294.002 0:17:40 24.047 298.255 0:17:50 24.575 302.515 0:18:00 25.322 306.598 0:18:10 27.327 310.913 0:18:20 30.599 315.685 0:18:30 25.234 320.897 0:18:40 24.26 324.426 0∶18∶50 29.553 329.416 O∶19:00 31.787 334.518 0:19:10 31.368 339.844 0:19∶20 30.048 344.797 0∶19∶30 32.578 350.03 0:19:40 28.207 355.107 0∶19∶50 31.823 360.144 O:20∶00 32.865 365.485 0∶20∶1O 35.55 371.268 0∶20:20 34.97 377.118 0∶20:30 29.303 382.392 O:20∶40 26.256 387.426 0∶20∶50 24.276 391.111 0∶21∶00 27.425 396.019 0∶21:1O 26.093 400.18 0∶21∶20 25.292 404.603 0:21∶30 26.768 409.295 0:21:40 25.389 413.387 0:21:50 25.052 417.938

[0040] Table 1-5

[0041] Time / h:mm:ss Instantaneous oxygen release rate / L / min Total oxygen release / L 0:22:00 21.399 421.548 0:22:10 22.934 425.217 0:22:20 26.683 429.343 0:22:30 24.883 433.667 0:22:40 23.596 437.541 0:22:50 23.926 441.619 0:23:00 29.856 445.935 0:23:10 35.082 451.29 0:23:20 36.802 457.203 0:23:30 32.512 462.634 0:23:40 41.294 469.426 0:23:50 42.52 475.925 0:24:00 42.25 483.564 0:24:10 35.145 490.065 0:24:20 32.625 495.495 0:24:30 35.663 501.151 0:24:40 32.659 507.132 0:24:50 30.28 512.492 0:25:00 27.733 517.42 0:25:10 23.114 521.781 0:25:20 18.425 525.299 0:25:30 9.779 527.782 0:25:40 2.248 528.593 0:25:50 0.253 528.737

[0042] It should be noted that the endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this article.

[0043] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "specific implementations", or "some specific implementations" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preventing ablation and leakage of a solid oxygen generator, characterized in that: include: The length of the heat insulating material is extended along the axial direction of the solid oxygen charge column so that the molten material at the end of the solid oxygen charge column flows in the longitudinal direction, and heat insulating fillers are added in the extended heat insulating material.

2. The method for preventing ablation and leakage of a solid oxygen generator according to claim 1, characterized in that: The extended length of the heat insulation material accounts for 10%-15% of the length of the solid oxygen powder column.

3. The method for preventing ablation and leakage of a solid oxygen generator according to claim 1, characterized in that: The thermal insulation material is a porous thermal insulation material selected from one or more of glass fiber, asbestos, and rock wool.

4. The method for preventing ablation and leakage of a solid oxygen generator according to any one of claims 1 to 3, characterized in that: The heat insulating filler is provided with 2-5 layers.

5. The method for preventing ablation and leakage of a solid oxygen generator according to claim 4, characterized in that: The heat insulating filler is one or more of expanded perlite, hollow polyamide fiber, porous ceramic clay, and ceramic microbeads.

6. A solid oxygen generator, characterized in that: It comprises a solid oxygen charge column and a heat insulating material wrapped around the outer surface of the solid oxygen charge column. The length of the heat insulating material is greater than that of the solid oxygen charge column so that the molten material at the end of the solid oxygen charge column flows in the longitudinal direction. A heat insulating filler is added inside the portion of the heat insulating material that exceeds the solid oxygen charge column.

7. The solid oxygen generator according to claim 6, characterized in that: The length of the heat insulating material is 10%-15% longer than the length of the solid oxygen powder column.

8. The solid oxygen generator according to claim 6, characterized in that: The thermal insulation material is a porous thermal insulation material selected from one or more of glass fiber, asbestos, and rock wool; And / or, the thermal insulation filler is one or more of expanded perlite, hollow polyamide fiber, porous ceramic clay, and ceramic microbeads.

9. The solid oxygen generator according to claim 6, characterized in that: The heat insulating filler is provided with 2-5 layers.

10. The solid oxygen generator according to claim 6, characterized in that: Calculated by weight percentage, the composition of the solid oxygen column is: 90.0-95.0% sodium chlorate, 3-5.5% potassium perchlorate, 1-4% catalyst, and 0.5-5% binder.

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