A vacuum crystallizer for ammonium perchlorate

Abstract

This invention discloses an ammonium perchlorate vacuum crystallizer, relating to the field of vacuum crystallizer technology, including a vacuum crystallization tank. To increase the residence time of the ammonium perchlorate solution in the vacuum crystallizer without increasing the energy consumption of the vacuum generator, the present invention sets the spray head as a cylindrical structure. When the ammonium perchlorate solution enters the spray chamber through the connecting pipe, the solution pushes the blades as it passes, causing the connecting pipe to rotate. Simultaneously, the upper baffle rotates. Due to the obstruction of the lower baffle, the spray holes on the spray head face the bottom of the filter screen. When the ammonium perchlorate solution in the spray chamber is sprayed out from the spray holes, it forms an upward spray, increasing the dispersibility of the ammonium perchlorate solution and thus increasing its residence time in the vacuum crystallization tank. This achieves a higher cooling rate of the ammonium perchlorate solution while maintaining low vacuum generator consumption.

Description

Technical Field

[0001] This invention relates to the field of vacuum crystallizer technology, and in particular to an ammonium perchlorate vacuum crystallizer. Background Technology

[0002] Ammonium perchlorate is a white crystalline solid with deliquescent properties. It is a strong oxidizing agent and can explode when mixed with reducing agents, organic matter, flammable materials such as sulfur, phosphorus, or metal powders. Contact with strong acids poses a risk of combustion and explosion. It is used in the manufacture of explosives and fireworks, and as an analytical reagent. Magnesium metal initiates the oxidation of aluminum, which in turn triggers the decomposition of ammonium perchlorate, producing a large amount of gas. It is used in rocket launches, the manufacture of ammonium perchlorate explosives, engraving agents, and artificial hail suppressants. Product packaging can be customized according to different user needs, using woven bags, cartons, iron drums, etc.

[0003] Ammonium perchlorate crystals are produced using a vacuum crystallizer. The working principle of a vacuum crystallizer is to cool and crystallize the material solution by drawing a vacuum, and it is a commonly used piece of equipment in current industrial crystallization processes.

[0004] In vacuum crystallizers, the raw material solution is mostly preheated by an external heater before being injected into the crystallizer. Upon entering the vacuum evaporator, a flash evaporation effect occurs immediately, instantly removing the steam. The cooling process then continues until a steady state is reached, at which point the solution temperature and saturated vapor pressure are in equilibrium.

[0005] Vacuum crystallization essentially relies on both concentration and cooling to create supersaturation and crystallize.

[0006] However, vacuum crystallizers have the following drawbacks in practical use:

[0007] Because the vacuum crystallizer needs to be evacuated in real time, the pressure difference between the inside and outside of the vacuum crystallizer is large. When the ammonium perchlorate solution is added to the vacuum crystallizer, the flow rate is relatively high. Therefore, the residence time of the ammonium perchlorate solution in the vacuum crystallizer is limited, which makes it difficult to improve the yield of ammonium perchlorate crystals. If the residence time of the ammonium perchlorate solution in the vacuum crystallizer is increased by increasing the height of the vacuum crystallizer, the equipment will occupy a large volume, and the energy consumption of the vacuum generator will increase significantly due to the increase in the internal space of the vacuum crystallizer.

[0008] Therefore, it is necessary to propose an ammonium perchlorate vacuum crystallizer to solve the above problems. Summary of the Invention

[0009] The purpose of this invention is to provide an ammonium perchlorate vacuum crystallizer to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: an ammonium perchlorate vacuum crystallizer, comprising a vacuum crystallization tank, wherein a vacuum suction tube is provided at the upper end of the vacuum crystallization tank, a vacuum generating pipe is connected to the vacuum suction tube, and a vacuum generator is connected to the end of the vacuum generating pipe away from the vacuum suction tube; a filter screen, a spray head and a filter cotton layer are arranged sequentially from top to bottom inside the vacuum crystallization tank; a rubber ring is fixedly provided at the outer ring of the filter screen, and the outer ring of the rubber ring is fixedly provided on the inner wall of the vacuum crystallization tank; and multiple sets of filter holes penetrating vertically are provided on the filter screen.

[0011] The injection head has a cylindrical structure and an internal injection chamber. A connecting pipe is fixedly installed on the side of the injection head, communicating with the interior of the injection chamber. A rotating tube is fixedly installed on the outer circumference of the connecting pipe at the end away from the injection head. A feed pipe is installed on the side of the connecting pipe away from the injection head and is fixedly installed on the vacuum crystallizer. The end of the feed pipe away from the connecting pipe extends to the outside of the vacuum crystallizer. An external pipe is integrally installed at the end of the feed pipe near the connecting pipe. A rotating groove is installed inside the external pipe, opening towards the side away from the feed pipe. The rotating tube is rotatably mounted in the rotating groove. The opening of the rotating groove is connected by a screw... A limiting ring is fixed in place, which is movably sleeved on the outer ring of the connecting pipe and limits the rotating pipe to a rotating groove. Multiple blades are fixedly arranged on the inner ring of the connecting pipe, and these blades are distributed at equal angles along the inner ring of the connecting pipe. An upper stop block is fixedly arranged above the end of the rotating pipe near the feed pipe. A lower stop block is fixedly welded to the lower end of the inner ring of the feed pipe near the external pipe, and the lower stop block corresponds to the upper stop block. Multiple injection holes are arranged below the injection chamber, and the ends of these injection holes away from the injection chamber are distributed openly towards the outer ring of the injection head.

[0012] Preferably, the filter cotton layer has a conical shell structure, and a support ring is fixedly provided at the lower outer ring of the filter cotton layer. The support ring is arranged around the inner ring of the vacuum crystallizer, and the outer ring of the support ring is fixedly connected to the inner wall of the vacuum crystallizer.

[0013] Preferably, a second support plate is movably attached to the inner ring of the filter cotton layer, and a blocking ring is fixedly provided at the lower end of the second support plate. Multiple sets of the second support plates are distributed along the inner ring of the filter cotton layer from top to bottom. A first support plate is attached to the upper inner wall of the filter cotton layer, and a support column is fixedly provided at the lower end of the first support plate. The end of the support column away from the first support plate is fixed to the lower inner wall of the vacuum crystallizer. A bracket is fixedly provided on the support column, and the end of the bracket away from the support column is fixedly connected to the inner ring of the corresponding blocking ring.

[0014] Preferably, a drying trough is provided on the support ring, a drive shaft is rotatably arranged in the drying trough, a cotton column is fixedly arranged on the drive shaft, an upper baffle plate is arranged above the cotton column, and a side baffle plate is arranged at the lower end of the upper baffle plate. The upper baffle plate and the side baffle plate are both fixedly arranged in the inner ring of the vacuum crystallizer. A drying channel is formed between the upper baffle plate and the cotton column. A material inlet is formed between the side of the upper baffle plate away from the inner ring of the vacuum crystallizer and the inner wall of the drying trough, and the material inlet leads to the drying channel. A scraper is fixedly arranged on the side of the side baffle plate away from the inner ring of the vacuum crystallizer. The scraper is movably attached to the outer ring of the cotton column. A discharge trough is connected to the end of the drying channel away from the inlet. A crystallization collection box is fixedly installed in the outer ring of the vacuum crystallizer. The end of the discharge trough away from the drying channel is connected to the interior of the crystallization collection box.

[0015] Preferably, a squeezing plate and a connecting rod are fixedly provided on the lower surface of the support ring, and a guide plate is fixedly connected to the lower end of the connecting rod. The guide plate is located below the squeezing plate. The end of the squeezing plate near the cotton column squeezes against the outer ring of the cotton column. A water film is formed between the end of the guide plate near the cotton column and the outer ring of the cotton column to form a gap. The end of the guide plate away from the cotton column is inclined towards the lower end of the vacuum crystallizer.

[0016] Preferably, multiple drying tanks are provided, and the multiple drying tanks are distributed at equal angles along the axis of the support ring.

[0017] Preferably, the upper end of the filter hole is the upper opening, the lower end of the filter hole is the lower opening, the filter screen has an elastic sheet structure, and the diameter of the lower opening is smaller than the diameter of the upper opening.

[0018] Preferably, a second cleaning pipe is fixedly provided at the lower end of the vacuum crystallizer, and the second cleaning pipe is connected to the interior of the vacuum crystallizer.

[0019] Preferably, a support leg is fixedly installed on the lower surface of the vacuum crystallizer, and the support leg is supported on the ground below the vacuum crystallizer.

[0020] Preferably, a crystallization discharge pipe is provided on one side of the lower end of the crystallization collection box, and a first cleaning pipe is provided on one side of the upper end of the vacuum crystallization tank. The first cleaning pipe connects to the interior of the vacuum crystallization tank, and one end of the first cleaning pipe that connects to the interior of the vacuum crystallization tank is located above the filter screen.

[0021] The technical effects and advantages of this invention are as follows:

[0022] 1. To increase the residence time of ammonium perchlorate solution in a vacuum crystallizer without increasing the energy consumption of the vacuum generator, this invention configures the spray head as a cylindrical structure. The ammonium perchlorate solution is input from the feed pipe. When the ammonium perchlorate solution enters the spray chamber through the connecting pipe, it passes through the blades. As the ammonium perchlorate solution passes through the blades, it pushes the blades, causing the connecting pipe to rotate. The upper baffle rotates synchronously with the connecting pipe. Due to the blocking effect of the lower baffle, the upper baffle stops after rotating 180°. At this point, the spray holes on the spray head face the bottom surface of the filter screen, and the ammonium perchlorate solution in the spray chamber is sprayed out from the spray holes. It forms an upward spray pattern, and multiple spray holes are provided. The ends of these spray holes, away from the spray chamber, are distributed in an open manner towards the outer ring of the spray head. This results in the ammonium perchlorate solution being sprayed out from multiple spray holes in an open spray pattern, increasing the dispersibility of the ammonium perchlorate solution and increasing its residence time in the vacuum crystallizer. This achieves the goal of increasing the residence time of the ammonium perchlorate solution in the vacuum crystallizer without increasing its height. It also increases the cooling rate of the ammonium perchlorate solution while keeping the vacuum generator's losses low, thereby improving the yield of the crystallized ammonium perchlorate solution.

[0023] 2. When the supply of ammonium perchlorate solution to the feed pipe is stopped, the blades will return to their original position due to the gravity of the spray head after losing the driving force of the ammonium perchlorate solution. This causes the spray holes to face away from the filter screen, allowing the residual ammonium perchlorate solution in the spray chamber to be discharged cleanly from the spray holes. This avoids the phenomenon that residual ammonium perchlorate solution may easily remain inside the spray chamber when the spray holes are set directly above the spray head, and also avoids the phenomenon that ammonium perchlorate solution crystallizes in the spray chamber and blocks the spray holes. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the ammonium perchlorate vacuum crystallizer of the present invention.

[0025] Figure 2 This is a schematic diagram of the internal structure of the ammonium perchlorate vacuum crystallizer of the present invention.

[0026] Figure 3 This is a schematic diagram of the filter structure of the present invention.

[0027] Figure 4 This is a schematic diagram of the spray head structure of the present invention.

[0028] Figure 5 For the present invention Figure 2 Enlarged schematic diagram of the structure at point A in the middle.

[0029] Figure 6 For the present invention Figure 2 Enlarged schematic diagram of the structure at point B.

[0030] In the diagram: 1. Vacuum crystallizer; 2. Vacuum generator; 3. Vacuum generating pipe; 4. Crystallization collection box; 5. Vacuum suction pipe; 6. First cleaning pipe; 7. Feed pipe; 8. Crystallization discharge pipe; 9. Support leg; 10. Filter screen; 11. Spray head; 12. Support column; 13. Support ring; 14. Filter cotton layer; 15. Second cleaning pipe; 16. Rubber ring; 17. Filter hole; 18. Upper opening; 19. Lower opening; 20. Spray chamber; 21. Connecting pipe; 22. Rotating groove; 23. External pipe; 24. Upper baffle; 25. Lower baffle; 26. Blade; 27. Rotating pipe; 28. Limiting ring; 29. ​​Spray hole; 30. Upper baffle plate; 31. Discharge groove; 32. Side baffle plate; 33. Scraper; 34. Drying channel; 35. Cotton column; 36. Drive shaft; 37. Water film forming gap; 38. Guide plate; 39. Connecting rod; 40. Extrusion plate; 41. Drying tank; 42. First support plate; 43. Second support plate; 44. Baffle ring; 45. Support. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] This invention provides, for example Figures 1-6 The ammonium perchlorate vacuum crystallizer shown includes a vacuum crystallization tank 1. A vacuum suction pipe 5 is installed at the upper end of the vacuum crystallization tank 1, and a vacuum generating pipe 3 is connected to the vacuum suction pipe 5. A vacuum generator 2 is connected to the end of the vacuum generating pipe 3 furthest from the vacuum suction pipe 5. Inside the vacuum crystallization tank 1, from top to bottom, a filter screen 10, a spray head 11, and a filter cotton layer 14 are arranged sequentially. In this invention, the ammonium perchlorate solution is first sprayed into the vacuum crystallization tank 1 through the spray head 11. Then, the vacuum generator 2 is activated, drawing a vacuum from the upper end of the vacuum crystallization tank 1. The ammonium perchlorate solution undergoes a flash evaporation effect in the vacuum crystallizer, and the ammonium perchlorate solution exhibits [the following properties] under negative pressure conditions. With a relatively low boiling point, it can be operated without excessively high temperatures. The boiling point of the ammonium perchlorate solution decreases as the vacuum level increases. This decrease in the boiling point of the ammonium perchlorate solution will cause it to boil violently and release water vapor. Even a small amount of water vaporization can carry away considerable heat, thus rapidly lowering the temperature of the ammonium perchlorate solution. The vapor is drawn away from the vacuum suction tube 5, and then the ammonium perchlorate solution begins to cool down. When it reaches a stable state, the temperature of the ammonium perchlorate solution is in equilibrium with the saturated vapor pressure. After cooling down, the ammonium perchlorate solution begins to crystallize. The ammonium perchlorate crystals fall onto the filter cotton layer 14, and the remaining waste liquid passes through the filter cotton layer 14 and reaches the lower end of the vacuum crystallizer 1.

[0033] To increase the residence time of the ammonium perchlorate solution in the vacuum crystallizer without increasing the energy consumption of the vacuum generator 2, the nozzle 11 is designed as a cylindrical structure. An injection chamber 20 is provided inside the nozzle 11. A connecting pipe 21 is fixedly installed on the side of the nozzle 11, communicating with the interior of the injection chamber 20. A rotating pipe 27 is fixedly installed on the outer circumference of the end of the connecting pipe 21 away from the nozzle 11. A feed pipe 7 is installed on the side of the connecting pipe 21 away from the nozzle 11, and is fixedly installed on the vacuum crystallizer 1. The end of the feed pipe 7 away from the connecting pipe 21 extends to the outside of the vacuum crystallizer 1. An external pipe 23 is integrally installed at the end of the feed pipe 7 near the connecting pipe 21. An internal rotating groove 22 is provided in the external pipe 23. The rotating groove 22 opens towards the side away from the feed pipe 7. The rotating pipe 27 is rotatably disposed in the rotating groove 22. A limit ring 28 is fixed to the opening of the rotating groove 22 by screws. The limit ring 28 is movably sleeved on the outer ring of the connecting pipe 21 and limits and blocks the rotating pipe 27 in the rotating groove 22. A blade 26 is fixedly provided on the inner ring of the connecting pipe 21. Multiple blades 26 are provided and are distributed at equal angles along the inner ring of the connecting pipe 21. An upper stop block 24 is fixedly provided above the end of the rotating pipe 27 near the feed pipe 7. A lower stop block 25 is fixedly welded to the lower end of the inner ring of the feed pipe 7 near the external pipe 23. The lower stop block 25 and the upper stop block are connected. Corresponding to 24, a spray hole 29 is provided below the spray chamber 20. The spray hole 29 connects the inside and outside of the spray chamber 20. The weight of the part of the spray head 11 with the spray hole 29 is greater than the weight of the rest of the spray head 11. The ammonium perchlorate solution is fed in from the feed pipe 7. When the ammonium perchlorate solution enters the spray chamber 20 through the connecting pipe 21, it passes through the blade 26. When the ammonium perchlorate solution passes through the blade 26, it pushes the blade 26, causing the connecting pipe 21 to rotate. When the connecting pipe 21 rotates, the upper stop block 24 rotates synchronously. Due to the blocking effect of the lower stop block 25, the upper stop block 24 stops after rotating 180°. At this time, the spray hole 29 on the spray head 11 faces the bottom surface of the filter screen 10. The perchlorate in the spray chamber 20... When the ammonium solution is ejected from the injection holes 29, it forms an upward spray. There are multiple injection holes 29, and the ends of the multiple injection holes 29 away from the injection chamber 20 are distributed in an open manner towards the outer ring of the injection head 11. This makes the ammonium perchlorate solution sprayed from the multiple injection holes 29 in an open spray state, which increases the dispersibility of the ammonium perchlorate solution and increases the residence time of the ammonium perchlorate solution in the vacuum crystallizer 1. This achieves the goal of increasing the residence time of the ammonium perchlorate solution in the vacuum crystallizer 1 without increasing the height of the vacuum crystallizer 1. It also increases the cooling rate of the ammonium perchlorate solution while keeping the wear of the vacuum generator 2 low, thereby improving the yield of the crystallized ammonium perchlorate solution.

[0034] Furthermore, the injection holes 29 are spiral channels, and the ammonium perchlorate solution ejected from multiple injection holes 29 is ejected in a spiral shape, which further increases the residence time of the ammonium perchlorate solution in the vacuum crystallizer 1.

[0035] It should be noted that the aforementioned openness refers to a fan-shaped outward diffusion state. When the supply of ammonium perchlorate solution to the feed pipe 7 is stopped, the blade 26, having lost the pushing force of the ammonium perchlorate solution, will reset due to the gravity of the spray head 11, causing the spray hole 29 to face away from the filter screen 10. This allows the residual ammonium perchlorate solution in the spray chamber 20 to be completely discharged from the spray hole 29, avoiding the phenomenon that residual ammonium perchlorate solution may easily remain inside the spray chamber 20 if the spray hole 29 is directly set above the spray head 11. If residual ammonium perchlorate solution remains inside the spray chamber 20, it will crystallize inside the spray chamber 20, causing the spray hole 29 to become clogged and difficult to clean.

[0036] The filter cotton layer 14 has a conical shell structure. A support ring 13 is fixedly installed at the lower outer ring of the filter cotton layer 14. The support ring 13 is arranged around the inner ring of the vacuum crystallizer 1, and the outer ring of the support ring 13 is fixedly connected to the inner wall of the vacuum crystallizer 1. After the ammonium perchlorate solution produces ammonium perchlorate crystals, waste liquid is generated at the same time. The ammonium perchlorate crystals and waste liquid are separated by the filtration of the filter cotton layer 14. The ammonium perchlorate crystals are filtered out above the filter cotton layer 14, and the waste liquid is filtered out below the filter cotton layer 14. A second cleaning pipe 15 is fixedly installed at the lower end of the vacuum crystallizer 1. The second cleaning pipe 15 is connected to the interior of the vacuum crystallizer 1. The waste liquid is finally discharged from the second cleaning pipe 15. A support leg 9 is fixedly installed on the lower surface of the vacuum crystallizer 1. The support leg 9 supports the ground below the vacuum crystallizer 1.

[0037] To improve the dryness of ammonium perchlorate crystals, a second support plate 43 is movably attached to the inner ring of the filter cotton layer 14. A blocking ring 44 is fixedly installed at the lower end of the second support plate 43. Multiple sets of the second support plate 43 are distributed from top to bottom along the inner ring of the filter cotton layer 14. A first support plate 42 is attached to the upper inner wall of the filter cotton layer 14. A support column 12 is fixedly installed at the lower end of the first support plate 42. The end of the support column 12 away from the first support plate 42 is fixed to the lower inner wall of the vacuum crystallizer 1. A bracket 45 is fixedly installed on the support column 12. The end of the bracket 45 away from the support column 12 is fixedly connected to the inner ring of the corresponding blocking ring 44. When the ammonium perchlorate crystals fall along the filter cotton layer 14, the waste liquid contained in the ammonium perchlorate crystals will be gradually absorbed by the filter cotton layer 14 and drip down from the bottom of the filter cotton layer 14. The ammonium perchlorate crystals first fall to the middle position directly above the filter cotton layer 14. At this time... When the ammonium perchlorate crystals contain the maximum amount of waste liquid, and the waste liquid comes into contact with the middle of the top of the filter cotton layer 14, the waste liquid is absorbed by the filter cotton layer 14 and drips to the bottom of the filter cotton layer 14. Since the filter cotton layer 14 has a conical structure, the waste liquid flows downward along the lower inner wall of the filter cotton layer 14. A large amount of waste liquid flows to the lower part of the filter cotton layer 14, resulting in higher humidity in the lower part of the filter cotton layer 14. Therefore, the second support plate 43 and the blocking ring 44 can block the waste liquid flowing downward along the lower inner wall of the filter cotton layer 14, so that the waste liquid flows directly downward along the blocking ring 44, reducing the humidity in the lower part of the filter cotton layer 14. This results in less waste liquid in the ammonium perchlorate crystals at the lower end of the filter cotton layer 14, thereby improving the dryness of the ammonium perchlorate crystals and avoiding the phenomenon of the separated waste liquid wetting the ammonium perchlorate crystals again.

[0038] In actual use, the second support plate 43 can also be attached to the upper surface of the filter cotton layer 14, so that the blocking ring 44 passes through the lower end of the filter cotton layer 14, further preventing the waste liquid contained in the filter cotton layer 14 from continuing to flow to the lower part of the filter cotton layer 14. It can be set according to actual needs.

[0039] Although the second support plate 43 and the baffle ring 44 at the bottom of the filter cotton layer 14 improve the dryness of the ammonium perchlorate crystals at the lower end of the filter cotton layer 14, a drying groove 41 is also provided on the support ring 13 to further improve the dryness of the ammonium perchlorate crystals. A drive shaft 36 is rotatably installed in the drying groove 41, and a cotton column 35 is fixedly installed on the drive shaft 36. An upper baffle plate 30 is installed above the cotton column 35, and a side baffle plate 32 is installed at the lower end of the upper baffle plate 30. Both the upper baffle plate 30 and the side baffle plate 32 are fixedly installed in the vacuum crystallization tank. At the inner ring of the vacuum crystallizer 1, a drying channel 34 is formed between the upper baffle plate 30 and the cotton column 35. A material inlet is formed between the side of the upper baffle plate 30 away from the inner ring of the vacuum crystallizer 1 and the inner wall of the drying tank 41, allowing material to enter. The material inlet leads to the drying channel 34. A scraper 33 is fixedly installed on the side of the side baffle plate 32 away from the inner ring of the vacuum crystallizer 1. The scraper 33 is movably attached to the outer ring of the cotton column 35. A discharge trough 31 is connected to the end of the drying channel 34 away from the inlet. A crystallization collection box 4 is fixedly installed on the outer ring of the vacuum crystallizer 1. The discharge trough 31 is located at the outer ring of the vacuum crystallizer 1. One end of the drying channel 34 is connected to the interior of the crystallization collection box 4. Ammonium perchlorate crystals sliding along the filter cotton layer 14 to the support ring 13 will enter the drying channel 34 through the material inlet. A motor (not shown in the figure; the motor can be installed at one end of the drive shaft 36, a common driving method, which will not be elaborated here; alternatively, a motor slot can be provided on one side of the drying tank 41) drives the drive shaft 36 to rotate. When the drive shaft 36 rotates, it drives the cotton column 35 to rotate synchronously. As the cotton column 35 rotates, the material inlet... Ammonium perchlorate crystals are pushed into the drying channel 34. The height of the drying channel 34 is set to allow a single ammonium perchlorate crystal to pass through easily. When a single ammonium perchlorate crystal passes through the drying channel 34, the wastewater remaining on its surface is absorbed by the cotton column 35. The finally dried ammonium perchlorate crystals are discharged from the discharge tank 31 into the crystallization collection box 4 for storage. The dryness of the dried ammonium perchlorate crystals is infinitely close to 100%. A crystallization discharge pipe 8 is provided on one side of the lower end of the crystallization collection box 4. The crystallization discharge pipe 8 is used to discharge the ammonium perchlorate crystals collected in the crystallization collection box 4.

[0040] The scraper 33 mentioned above serves to prevent ammonium perchlorate crystals from entering the lower part of the vacuum crystallizer 1 through the space between the side baffle 32 and the cotton column 35.

[0041] Considering that the cotton column 35 is prone to saturation when continuously absorbing wastewater from ammonium perchlorate crystals, a pressing plate 40 and a connecting rod 39 are fixedly installed on the lower surface of the support ring 13. A guide plate 38 is fixedly connected to the lower end of the connecting rod 39. The guide plate 38 is located below the pressing plate 40. The end of the pressing plate 40 near the cotton column 35 presses against the outer ring of the cotton column 35. A water film gap 37 is formed between the end of the guide plate 38 near the cotton column 35 and the outer ring of the cotton column 35. The end of the guide plate 38 away from the cotton column 35 is inclined towards the lower end of the vacuum crystallizer 1. As the cotton column 35 rotates, the pressing plate 40 can squeeze the water droplets on the cotton column 35 into the lower end of the vacuum crystallizer 1. Since the guide plate 38 is blocked below the pressing plate 40, the wastewater will drip down along the guide plate 38 into the vacuum crystallizer. The wastewater flows into the lower end of the tank 1 and is not absorbed by the cotton column 35 again. When the extrusion plate 40 extrudes the cotton column 35, in addition to the water droplets that drip directly downwards, water droplets also flow downwards along the outer ring of the cotton column 35. In order to prevent the water droplets from wetting the upper end of the cotton column 35 near the drying channel 34 during the downward flow of the water droplets, the width of the water film forming gap 37 is set to be small. When the wastewater flowing along the outer ring of the cotton column 35 reaches the water film forming gap 37, a water film will be formed at the water film forming gap 37. Due to the obstruction of the water film, the wastewater preferentially flows through the surface of the guide plate 38 to the lower end of the inner wall of the vacuum crystallizer 1, avoiding the phenomenon of wastewater continuing to wet the position near the drying channel 34 along the cotton column 35, thus fully ensuring the drying effect of the cotton column 35 on the continuous discharge of ammonium perchlorate crystals.

[0042] In actual use, multiple drying tanks 41 are provided, and the multiple drying tanks 41 are distributed at equal angles along the axis of the support ring 13, which improves the efficiency of ammonium perchlorate crystal discharge.

[0043] Considering that ammonium perchlorate solution is prone to crystallization during the spraying process in vacuum crystallizer 1, the initially condensed ammonium perchlorate crystals are small in size and tend to be closer to the spray head 11. Since the spray head 11 is close to the vacuum suction tube 5, in order to prevent the small ammonium perchlorate crystals from being sucked into the vacuum suction tube 5, a filter screen 10 is provided between the vacuum suction tube 5 and the spray head 11. The filter screen 10 is provided with multiple sets of vertically penetrating filter holes 17, which are used to allow water vapor to pass through. The smaller ammonium perchlorate crystals are blocked below the filter screen 10, thus preventing the phenomenon of small ammonium perchlorate crystals being sucked out by the vacuum suction tube 5.

[0044] The upper end of the filter hole 17 is the upper opening 18, and the lower end is the lower opening 19. The filter screen 10 has an elastic sheet structure, with the diameter of the lower opening 19 being smaller than the diameter of the upper opening 18. A rubber ring 16 is fixedly installed on the outer ring of the filter screen 10, and the outer ring of the rubber ring 16 is fixedly installed on the inner wall of the vacuum crystallization tank 1. Both the rubber ring 16 and the filter screen 10 have a certain degree of elasticity. When water vapor passes through the filter hole 17 at high speed, it will cause the filter screen 10 to bulge upward. When the water vapor flow rate is lower than the flow rate passing through the filter hole 17 in the previous second, the rubber ring bulges upward. The elastic recovery of the rubber ring 16 and the filter screen 10 will cause the filter screen 10 to bulge downwards and return to its original position. When the filter screen 10 bulges upwards, the elasticity of the filter screen 10 will reduce the diameter of the lower opening 19, thereby preventing small ammonium perchlorate crystals from being discharged downwards through the filter holes 17. When the filter screen 10 bulges downwards, the elasticity of the filter screen 10 will increase the diameter of the lower opening 19, thereby promoting the downward detachment of ammonium perchlorate crystals that are blocked in the filter holes 17, thus preventing blockage at the filter holes 17.

[0045] A first cleaning pipe 6 is provided on one side of the upper end of the vacuum crystallizer 1. The first cleaning pipe 6 connects to the interior of the vacuum crystallizer 1. One end of the first cleaning pipe 6 that connects to the interior of the vacuum crystallizer 1 is located above the filter screen 10. The first cleaning pipe 6 is used to discharge impurities and other substances accumulated on the upper surface of the filter screen 10.

Claims

1. An ammonium perchlorate vacuum crystallizer, comprising a vacuum crystallization tank (1), wherein a vacuum suction tube (5) is provided at the upper end of the vacuum crystallization tank (1), a vacuum generating pipe (3) is connected to the vacuum suction tube (5), and a vacuum generator (2) is connected to the end of the vacuum generating pipe (3) away from the vacuum suction tube (5), characterized in that: The vacuum crystallizer (1) is provided with a filter screen (10), a spray head (11) and a filter cotton layer (14) arranged from top to bottom inside. A rubber ring (16) is fixedly arranged on the outer ring of the filter screen (10), and the outer ring of the rubber ring (16) is fixedly arranged on the inner ring wall of the vacuum crystallizer (1). The filter screen (10) is provided with multiple sets of filter holes (17) that run vertically through it. The spray head (11) has a cylindrical structure, and a spray chamber (20) is provided inside the spray head (11). A connecting pipe (21) is fixedly provided on the side of the spray head (11), and the connecting pipe (21) communicates with the inside of the spray chamber (20). A rotating pipe (27) is fixedly provided on the outer ring of the end of the connecting pipe (21) away from the spray head (11). A feed pipe (7) is provided on the side of the connecting pipe (21) away from the spray head (11). The feed pipe (7) is fixedly provided on the vacuum crystallizer (1). The end of the feed pipe (7) away from the connecting pipe (21) extends to the outside of the vacuum crystallizer (1). An external pipe (23) is integrally provided at the end of the feed pipe (7) near the connecting pipe (21). A rotating groove (22) is provided inside the external pipe (23). The rotating groove (22) opens towards the side away from the feed pipe (7). The rotating pipe (27) is rotatably disposed in the rotating groove (22). A limit ring (28) is fixed at the opening of the rotating groove (22) by screws. The limit ring (28) is movable. The moving sleeve is installed on the outer ring of the connecting pipe (21) and limits and blocks the rotating pipe (27) in the rotating groove (22). A blade (26) is fixedly installed on the inner ring of the connecting pipe (21). Multiple blades (26) are provided and are distributed at equal angles along the inner ring of the connecting pipe (21). An upper stop block (24) is fixedly installed above the end of the rotating pipe (27) near the feed pipe (7). A lower stop block (25) is fixedly welded to the lower end of the inner ring of the feed pipe (7) near the external pipe (23). The lower stop (25) corresponds to the upper stop (24). A spray hole (29) is provided below the spray chamber (20). The weight of the part of the spray head (11) with the spray hole (29) is greater than the weight of the rest of the spray head (11). The spray hole (29) is a spiral channel. The spray hole (29) connects the inside and outside of the spray chamber (20). There are multiple spray holes (29). The ends of the multiple spray holes (29) away from the spray chamber (20) are distributed in an open manner towards the outer ring of the spray head (11).

2. The ammonium perchlorate vacuum crystallizer according to claim 1, characterized in that: The filter cotton layer (14) has a conical shell structure. A support ring (13) is fixedly provided at the lower outer ring of the filter cotton layer (14). The support ring (13) is arranged around the inner ring of the vacuum crystallizer (1), and the outer ring of the support ring (13) is fixedly connected to the inner wall of the vacuum crystallizer (1).

3. The ammonium perchlorate vacuum crystallizer according to claim 2, characterized in that: A second support plate (43) is movably attached to the inner ring of the filter cotton layer (14). A blocking ring (44) is fixedly provided at the lower end of the second support plate (43). Multiple sets of the second support plate (43) are distributed from top to bottom along the inner ring of the filter cotton layer (14). A first support plate (42) is attached to the upper inner wall of the filter cotton layer (14). A support column (12) is fixedly provided at the lower end of the first support plate (42). The end of the support column (12) away from the first support plate (42) is fixed to the lower inner wall of the vacuum crystallizer (1). A bracket (45) is fixedly provided on the support column (12). The end of the bracket (45) away from the support column (12) is fixedly connected to the inner ring of the corresponding blocking ring (44).

4. The ammonium perchlorate vacuum crystallizer according to claim 2, characterized in that: A drying groove (41) is provided on the support ring (13). A drive shaft (36) is rotatably arranged in the drying groove (41). A cotton column (35) is fixedly arranged on the drive shaft (36). An upper baffle plate (30) is arranged above the cotton column (35). A side baffle plate (32) is arranged at the lower end of the upper baffle plate (30). The upper baffle plate (30) and the side baffle plate (32) are both fixedly arranged in the inner ring of the vacuum crystallizer (1). A drying channel (34) is formed between the upper baffle plate (30) and the cotton column (35). The upper baffle plate (30) is far away from the inside of the vacuum crystallizer (1). A material inlet is formed between one side of the ring and the inner wall of the drying tank (41) for material entry. The material inlet leads to the drying channel (34). A scraper (33) is fixedly provided on the side of the side baffle plate (32) away from the inner ring of the vacuum crystallizer (1). The scraper (33) is movably attached to the outer ring of the cotton column (35). A discharge trough (31) is connected to the end of the drying channel (34) away from the inlet. A crystallization collection box (4) is fixedly installed on the outer ring of the vacuum crystallizer (1). The end of the discharge trough (31) away from the drying channel (34) is connected to the interior of the crystallization collection box (4).

5. The ammonium perchlorate vacuum crystallizer according to claim 4, characterized in that: The lower surface of the support ring (13) is fixedly provided with an extrusion plate (40) and a connecting rod (39). The lower end of the connecting rod (39) is fixedly connected with a guide plate (38). The guide plate (38) is located below the extrusion plate (40). The end of the extrusion plate (40) near the cotton column (35) is pressed against the outer ring of the cotton column (35). A water film is formed between the end of the guide plate (38) near the cotton column (35) and the outer ring of the cotton column (35), forming a gap (37). The end of the guide plate (38) away from the cotton column (35) is inclined toward the lower end of the vacuum crystallizer (1).

6. The ammonium perchlorate vacuum crystallizer according to claim 4, characterized in that: The drying tank (41) is provided in multiple ways, and the multiple drying tanks (41) are distributed at equal angles along the axis of the support ring (13).

7. The ammonium perchlorate vacuum crystallizer according to claim 1, characterized in that: The upper end of the filter hole (17) is the upper opening (18), and the lower end of the filter hole (17) is the lower opening (19). The filter screen (10) has an elastic sheet structure, and the diameter of the lower opening (19) is smaller than the diameter of the upper opening (18).

8. The ammonium perchlorate vacuum crystallizer according to claim 1, characterized in that: The lower end of the vacuum crystallizer (1) is fixedly provided with a second cleaning pipe (15), which is connected to the interior of the vacuum crystallizer (1).

9. The ammonium perchlorate vacuum crystallizer according to claim 1, characterized in that: A support leg (9) is fixedly installed on the lower surface of the vacuum crystallizer (1), and the support leg (9) is supported on the ground below the vacuum crystallizer (1).

10. An ammonium perchlorate vacuum crystallizer according to claim 4, characterized in that: A crystallization discharge pipe (8) is provided on one side of the lower end of the crystallization collection box (4), and a first cleaning pipe (6) is provided on one side of the upper end of the vacuum crystallization tank (1). The first cleaning pipe (6) is connected to the interior of the vacuum crystallization tank (1), and one end of the first cleaning pipe (6) connected to the interior of the vacuum crystallization tank (1) is located above the filter screen (10).

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