Ammonium perchlorate filtering and drying device and drying method thereof

Abstract

The application belongs to the technical field of drying devices, and relates to an ammonium perchlorate filtering and drying device and a drying method thereof. The drying device comprises a drying box, a heating element is arranged in the drying box, a filtering assembly is arranged in the drying box, rotating plates are rotatably arranged at two ends of the drying box, and two mounting plates of the filtering assembly are slidably connected in the drying box. One of the two mounting plates of the same filtering assembly is fixedly connected with the corresponding rotating plate, and the other mounting plate is rotatably connected with the rotating plate. The rotating plate drives the filtering assembly to rotate, filters the ammonium perchlorate, and makes the caked ammonium perchlorate stay on the filter screen. The filtering assembly is folded, and then the caked ammonium perchlorate is preliminarily extruded and crushed. The ammonium perchlorate is dispersed into the folds of the filtering assembly, the ammonium perchlorate is prevented from being accumulated together, and the crushing efficiency is improved. The filtering assembly is twisted and deformed, the ammonium perchlorate is extruded and crushed, and the drying efficiency and drying effect are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of drying devices, and relates to an ammonium perchlorate filtering and drying device and a drying method thereof. BACKGROUND

[0002] As a strong oxidant, ammonium perchlorate is widely used in aerospace and people's life. In order to improve the purity and chemical stability of ammonium perchlorate and improve the safety of storage and use, it is necessary to dry ammonium perchlorate.

[0003] The hygroscopicity of ammonium perchlorate makes ammonium perchlorate easy to stick together into a block. In the drying process, the sticking of ammonium perchlorate will cause the heat transfer efficiency to be reduced, the heat and moisture transfer path to be blocked, and the internal moisture to be difficult to quickly spread to the surface, thereby affecting the drying efficiency and the drying effect.

[0004] To solve the above problems, the application provides an ammonium perchlorate filtering and drying device and a drying method thereof. SUMMARY

[0005] To solve the problems in the background art, the application provides an ammonium perchlorate filtering and drying device and a drying method thereof.

[0006] In order to achieve the above purpose, the technical scheme adopted by the application is as follows: an ammonium perchlorate filtering and drying device, comprising a drying box, a heating element is arranged in the drying box; a filtering assembly is arranged in the drying box, rotating plates are rotatably arranged at both ends of the drying box; both ends of the filtering assembly are slidably connected in the mounting plates; one of the two mounting plates on the same filtering assembly is fixedly connected with one of the rotating plates, and the other mounting plate is rotatably connected with the other rotating plate; a driving element for unfolding or folding the filtering assembly is arranged in the mounting plate; the rotating plate drives the filtering assembly to rotate to filter the ammonium perchlorate, and then the filtering assembly is folded, one end of the filtering assembly is driven by the mounting plate to rotate relative to the rotating plate, and then the filtering assembly is twisted to crush the ammonium perchlorate remaining on the filtering assembly.

[0007] Further, the filtering assembly comprises a filter screen and an extension piece; the two ends of the filter screen are connected with the extension pieces, the two ends of the extension piece are connected with connecting columns, and the connecting columns are slidably arranged in the corresponding mounting plates; the two connecting columns are away from each other, and the filtering assembly is unfolded; the two connecting columns are close to each other, and the extension assembly is folded.

[0008] Further, the extension piece comprises mounting rods and elastic strips, the mounting rods and the elastic strips are both provided in plurality, and the mounting rods and the elastic strips are alternately arranged, two adjacent mounting rods are connected through the elastic strips, and the mounting rods and the elastic strips are both fixedly connected with the filter screen.

[0009] Further, the driving member comprises a sliding block which is slidingly arranged in the mounting plate, a limiting block is slidingly arranged on the sliding block, an inclined block is fixedly connected to one end of the connecting column which extends into the mounting plate, and an inclined surface which cooperates with the inclined block is arranged on the limiting block.

[0010] Further, a screw rod is rotatably arranged in the mounting plate, a third motor which is drivingly connected with the screw rod is arranged in the mounting plate, and the sliding block is threadedly connected with the screw rod.

[0011] Further, a connecting shaft is fixedly connected between the two rotating plates.

[0012] The filtering assembly is provided with two filtering assemblies which are arranged on the two sides of the connecting shaft.

[0013] Further, a first motor is fixedly arranged on the drying box, a driving wheel is connected to the output shaft of the first motor, a driven wheel is connected to one end of the connecting shaft, and a belt is wound between the driven wheel and the driving wheel.

[0014] Further, the drying box is arranged on a fixing base, a fixing column is arranged on the fixing base, and the drying box is connected with the fixing column.

[0015] Further, the heating member is a heating layer which is embeddedly arranged in the side wall of the drying box.

[0016] The high ammonium perchlorate filtering and drying method provided by the application comprises the following steps:

[0017] S1, ammonium perchlorate is added into the drying box;

[0018] S2, the heating member is started to dry the ammonium perchlorate in the drying box;

[0019] S3, the rotating plate is rotated to drive the mounting plate to rotate, and the mounting plate drives the filtering assembly to rotate to filter the ammonium perchlorate, and the agglomerated ammonium perchlorate is retained on the filtering assembly;

[0020] S4, the filtering assembly is folded;

[0021] S5, one end of the filtering assembly is rotated relative to the rotating plate by the mounting plate to twist the filtering assembly and crush the agglomerated ammonium perchlorate.

[0022] Compared with the prior art, the present application has the following beneficial effects: when the filter assembly is unfolded, the rotating plate is rotated, the rotating plate drives the filter assembly to rotate, the ammonium perchlorate is filtered, and the caked ammonium perchlorate is retained on the filter screen. The filter assembly is folded, and then the caked ammonium perchlorate is preliminarily extruded and crushed. And the ammonium perchlorate is dispersed into the folds of the filter assembly, which avoids the ammonium perchlorate from piling up together, and is beneficial to improve the crushing efficiency and then improve the drying efficiency.

[0023] One of the mounting plates is rotated relative to the rotating plate, and then the filter assembly is twisted and deformed, the ammonium perchlorate is extruded and crushed, which is beneficial to improve the drying efficiency and drying effect.

[0024] When the filter assembly is filtering, the ammonium perchlorate is disturbed and turned, which is helpful to improve the drying efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the overall structure schematic view in the first direction of the present application;

[0026] Figure 2 is the overall structure schematic view in the second direction of the present application;

[0027] Figure 3 is the internal structure schematic view of the drying box in the present application;

[0028] Figure 4 is the A part enlarged view of the present application; Figure 3

[0029] Figure 5 is the state schematic view of the first filter assembly and the second filter assembly in the present application at the initial time;

[0030] Figure 6 is the B part enlarged view of the present application; Figure 5

[0031] Figure 7 is the sectional view of the mounting plate in the present application;

[0032] Figure 8 is the C part enlarged view of the present application; Figure 7

[0033] Figure 9 is the structure schematic view of the sliding block in the present application;

[0034] Figure 10 is the structure schematic view of the filter assembly in the present application in the folded state.

[0035] ​​​In the diagram: 1. Fixed base; 2. Fixed column; 3. Drying oven; 4. First motor; 5. First rotating plate; 6. Second rotating plate; 7. Suction pipe; 8. Feed pipe; 9. Discharge pipe; 10. Second motor; 11. Driven wheel; 12. Belt; 13. Drive wheel; 14. Connecting shaft; 15. Filter screen; 16. Heating layer; 17. Mounting plate; 18. First slide groove; 19. Third motor; 20. Lead screw; 21. Second slide groove; 22. Slider; 23. Mounting rod; 24. Limiting block; 241. First inclined plane; 242. Second inclined plane; 25. Inclined block; 26. Connecting column; 27. Relief groove; 28. Spring; 29. ​​Elastic strip. Detailed Implementation

[0036] 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.

[0037] like Figures 1-10 As shown, the technical solution adopted by the present invention is as follows: an ammonium perchlorate filtration and drying device, comprising a drying box 3 and a filter assembly.

[0038] like Figure 1 , Figure 2 As shown, the drying chamber 3 is installed on the fixed base 1. Two fixed columns 2 are installed on the upper end of the fixed base 1. The drying chamber 3 is installed between the two fixed columns 2, and the axis of the drying chamber 3 is set horizontally.

[0039] A feed pipe 8 is installed on the drying chamber 3. A discharge pipe 9 is installed at the bottom of the drying chamber 3. The ammonium perchlorate to be dried is put into the drying chamber 3 through the feed pipe 8. The dried ammonium perchlorate is discharged through the discharge pipe 9.

[0040] A heating element is installed inside the drying oven 3 to heat the ammonium perchlorate inside the drying oven 3, thereby drying the ammonium perchlorate. In this embodiment, the heating element includes a heating layer 16, which is embedded in the side wall of the drying oven 3.

[0041] The drying chamber 3 is equipped with a suction pipe 7, which is connected to an external suction pump. The suction pipe 7 is used to draw air out of the drying chamber 3, so that the air pressure inside the drying chamber 3 is lower than the atmospheric pressure, which helps to accelerate the evaporation of moisture and improve the drying efficiency.

[0042] Rotating plates are rotatably mounted at both ends of the drying oven 3. A connecting shaft 14 is fixedly connected between the two rotating plates, and the connecting shaft 14 is coaxial with the drying oven 3.

[0043] In this embodiment, two rotating plates are defined as a first rotating plate 5 and a second rotating plate 6 for convenience of description.

[0044] The first motor 4 is installed on the drying box 3, and a driving wheel 13 is fixedly connected to an output shaft of the first motor 4. One end of a connecting shaft 14 extends to the outside of the rotating plate and is fixedly connected to a driven wheel 11. A belt 12 is wound between the driven wheel 11 and the driving wheel 13.

[0045] The filter assembly is installed between the first rotating plate 5 and the second rotating plate 6. In this embodiment, two filter assemblies are provided, and the two filter assemblies are arranged on both sides of the connecting shaft 14.

[0046] Each filter assembly includes a filter screen 15 and an expansion piece. The expansion piece is installed at both ends of the filter screen 15. When the expansion piece is extended, the filter assembly is unfolded. When the filter assembly rotates around the connecting shaft 14, the filter assembly filters the ammonium perchlorate in the drying box 3, so that the caked ammonium perchlorate is retained on the filter assembly. Then, the filter assembly is folded, and the caked ammonium perchlorate is crushed during the folding of the filter assembly, which is beneficial to improve the drying effect and efficiency.

[0047] As shown in Figure 10 The expansion piece includes a mounting rod 23 and an elastic strip 29. The mounting rod 23 and the elastic strip 29 are both provided in plurality, and the mounting rod 23 and the elastic strip 29 are arranged alternately, and two adjacent mounting rods 23 are connected by the elastic strip 29. The mounting rod 23 and the elastic strip 29 are both fixedly connected to the filter screen 15. In a natural state, the elastic strip 29 is in a C shape.

[0048] The mounting rod 23 at both ends of the expansion piece is connected to a connecting column 26. The connecting column 26 is slidingly arranged in a mounting plate 17. The mounting plate 17 is provided with a first sliding groove 18 which slidingly cooperates with the connecting column 26. A driving piece is installed in the mounting plate 17, and the driving piece drives the connecting column 26 to slide along the first sliding groove 18, so that the two connecting columns 26 on the same expansion piece move away from each other, the elastic strip 29 is straightened, the expansion piece is unfolded, and then the filter screen 15 is unfolded. The two connecting columns 26 on the same expansion piece move close to each other, and the filter assembly is folded.

[0049] When the filter assembly is in an unfolded state, the corresponding elastic piece is in a straightened state, and the elastic piece blocks the corresponding first sliding groove 18.

[0050] The driving member comprises the sliding blocks 22 and the limiting blocks 24, the second sliding grooves 21 are formed in the mounting plates 17, and the two sliding blocks 22 are slidably arranged in the second sliding grooves 21. The two sliding blocks 22 correspond to the two connecting columns 26 in the same mounting plate 17 in a one-to-one manner. The limiting blocks 24 are elastically and slidably connected to the sliding blocks 22. Specifically, the letting-position grooves 27 are formed in the sliding blocks 22, the limiting blocks 24 are slidably arranged in the letting-position grooves 27, springs 28 are arranged in the letting-position grooves 27, and the springs 28 are fixedly connected between the limiting blocks 24 and the sliding blocks 22. As shown in Figs. Figure 7 、 Figure 8 The upper end of the limiting block 24 is provided with the first inclined surface 241 and the second inclined surface 242. The end of the connecting column 26 extending into the mounting plate 17 is fixedly connected with the inclined block 25. The inclined block 25 cooperates with the limiting block 24. The first inclined surface 241 cooperates with the inner side of the inclined block 25, i.e. the side close to the other inclined block 25, and the second inclined surface 242 cooperates with the outer side of the inclined block 25, i.e. the side away from the other inclined block 25.

[0051] The lead screws 20 are rotatably arranged in the mounting plates 17, the third motors 19 are arranged in the mounting plates 17, and the output shafts of the third motors 19 are fixedly connected with the lead screws 20. The sliding blocks 22 are threadedly connected with the lead screws 20. In this embodiment, the third motor 19 is a double-shaft motor, the two output shafts of the third motor 19 are respectively drivingly connected with the two lead screws 20, the two lead screws 20 correspond to the two sliding blocks 22 in a one-to-one manner, and the sliding blocks 22 are threadedly connected with the corresponding lead screws 20. The third motor 19 rotates, the lead screws 20 rotate, and then the two sliding blocks 22 move close to or away from each other.

[0052] The limiting block 24 is arranged on the side of the corresponding inclined block 25 close to the other inclined block 25, the two sliding blocks 22 move away from each other, the sliding block 22 pushes the inclined block 25 to move through the limiting block 24, the two connecting columns 26 move away from each other, and then the filter assembly is unfolded. When the filter assembly is completely unfolded, the inclined block 25 cannot move further. With the continuous movement of the two sliding blocks 22, the limiting block 24 moves downward under the extrusion of the inclined block 25, and then the limiting block 24 moves to the outer side of the inclined block 25. After losing the limiting of the limiting block 24, the elastic strip 29 restores the deformation, and then the filter assembly returns to the folded state.

[0053] In the two mounting plates 17 on the same filter assembly, the middle part of one mounting plate 17 is fixedly connected with the second rotating plate 6, and the middle part of the other mounting plate 17 is rotatably connected with the first rotating plate 5. The second motor 10 is arranged on the first rotating plate 5, and the output shaft of the second motor 10 is fixedly connected with the middle part of the corresponding mounting plate 17. When the filter assembly is in the folded state, the corresponding mounting plate 17 is driven to rotate by the second motor 10, the end of the filter assembly is rotated, and then the filter assembly is twisted to crush the ammonium perchlorate on the filter assembly.

[0054] Working principle: In order to facilitate the description, the two filter assemblies are named as the first filter assembly and the second filter assembly. Initially, the first filter assembly is in the unfolded state, and the telescopic part in the first filter assembly is in the straightened state and blocks the corresponding first sliding groove 18. The limiting block 24 in the first filter assembly abuts against the inner side of the corresponding inclined block 25. The second filter assembly is in the folded state. As shown in the figure, the first filter assembly is on the left side of the connecting shaft 14, and the second filter assembly is on the right side of the connecting shaft 14. Figure 3

[0055] In use, ammonium perchlorate is put into the drying box 3 through the feeding pipe 8, and the height of the ammonium perchlorate in the drying box 3 is lower than the connecting shaft 14. The heating layer 16 is started to heat and dry the ammonium perchlorate in the drying box 3.

[0056] During the drying process, the first motor 4 is started to drive the driving wheel 13 to rotate, the driving wheel 13 drives the driven wheel 11 to rotate through the belt 12, the connecting shaft 14 rotates, the first rotating plate 5 and the second rotating plate 6 rotate, and the first filter assembly and the second filter assembly rotate. As shown in the direction, the connecting shaft 14 rotates counterclockwise. The first filter assembly rotates counterclockwise and passes through the lower part of the drying box 3, the first filter assembly filters the ammonium perchlorate in the drying box 3, until the first filter assembly moves to the right side of the connecting shaft 14 and is in a horizontal state, the agglomerated ammonium perchlorate is retained on the first filter assembly, and the first motor 4 is paused. The first filter assembly remains on the right side of the connecting shaft 14 and is in a horizontal state, and at this time the second filter assembly is on the left side of the connecting shaft 14. Figure 3 It should be noted that since the telescopic part in the first filter assembly blocks the corresponding first sliding groove 18, when the first filter assembly filters the ammonium perchlorate, the ammonium perchlorate can be prevented from entering the first sliding groove 18.

[0057] After that, in the first filter assembly, the third motor 19 is started to make the two sliding blocks 22 move away from each other, and since the two inclined blocks 25 cannot move away further, the limiting block 24 moves downward along the accommodation groove 27, and then the limiting block 24 moves to the outer side of the inclined block 25. After losing the limiting of the limiting block 24, the elastic strip 29 quickly recovers the elastic deformation, the first filter assembly is folded, the mounting rod 23 moves to the vertical state, and the first filter assembly is folded to extrude the agglomerated ammonium perchlorate thereon, and the agglomerated ammonium perchlorate is preliminarily crushed. The agglomerated ammonium perchlorate is dispersed into the wrinkles on the filter screen 15, which avoids the accumulation of ammonium perchlorate on the filter screen 15 and is conducive to improving the crushing effect.

[0058]

[0059] ​​Afterwards, the second motor 10 on the first filter assembly is started, the second motor 10 drives the corresponding mounting plate 17 to rotate, and then the one end of the first filter assembly is rotated.

[0060] Afterwards, the first filter assembly is reset to the folded state by the second motor 10.

[0061] On the first filter assembly, the third motor 19 is started, the lead screw 20 is rotated, the two sliding blocks 22 are close to each other, and the two limiting blocks 24 are close to each other. When the limiting block 24 contacts the inclined block 25, the inclined block 25 extrudes the second inclined surface 242 to make the limiting block 24 move downward, and then the limiting block 24 moves to the inner side of the inclined block 25. Then, the two sliding blocks 22 are away from each other, the two limiting blocks 24 are away from each other, the limiting block 24 pushes the inclined block 25 to move outward through the first inclined surface 241, the two inclined blocks 25 are away from each other, the two connecting columns 26 are away from each other, and then the first filter assembly is unfolded.

[0062] It should be noted that the elastic force of the spring 28 and the elastic strip 29 should be reasonably set, so that the limiting block 24 can push the inclined block 25 to move outward through the first inclined surface 241 to unfold the telescopic part, and when the inclined block 25 cannot continue to move, the limiting block 24 can move into the relief groove 27 by overcoming the elastic force of the spring 28.

[0063] When the first filter assembly is completely unfolded, as the two limiting blocks 24 continue to move away from each other, the inclined block 25 extrudes the first inclined surface 241 to make the limiting block 24 move downward, and then the limiting block 24 moves to the outer side of the inclined block 25, and the inclined block 25 loses the limiting of the limiting block 24. The elastic strip 29 restores the deformation, and then the first filter assembly quickly moves to the folded state.

[0064] When it is necessary to filter the agglomerated ammonium perchlorate in the drying box 3 again, the second filter assembly is unfolded, and then the connecting shaft 14 is rotated to rotate the first filter assembly and the second filter assembly, and the second filter assembly filters the ammonium perchlorate in the drying box 3.

[0065] When the filter assembly rotates along the drying box 3 to filter the ammonium perchlorate, the ammonium perchlorate is constantly disturbed and turned, which helps to make the ammonium perchlorate evenly heated and helps to improve the drying effect.

[0066] The ammonium perchlorate filtering and drying method in the application comprises the following steps:

[0067] S1, ammonium perchlorate is added into the drying box 3.

[0068] S2, the heating element is started, and the heating element dries the ammonium perchlorate in the drying box 3.

[0069] S3, the rotating plate is rotated, the rotating plate drives the mounting plate 17 to rotate, the mounting plate 17 drives the filtering assembly to rotate, the ammonium perchlorate is filtered, and the caked ammonium perchlorate is retained on the filtering assembly.

[0070] S4, the filtering assembly is folded.

[0071] S5, one end of the filtering assembly is rotated relative to the rotating plate by the mounting plate 17, so that the filtering assembly is twisted, and the caked ammonium perchlorate is crushed by extrusion.

[0072] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can make modifications to the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to part of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An ammonium perchlorate filtering and drying device, comprising a drying box (3) provided with a heating element inside; characterized in that: The drying box (3) is provided with a filtering assembly, and both ends of the drying box (3) are rotatably provided with rotating plates; both ends of the filtering assembly are slidably connected in the mounting plates (17); among the two mounting plates (17) on the same filtering assembly, one mounting plate (17) is fixedly connected with one rotating plate, and the other mounting plate (17) is rotatably connected with the other rotating plate; the mounting plate (17) is provided with a driving member for unfolding or folding the filtering assembly; The rotating plate drives the filtering assembly to rotate to filter the ammonium perchlorate, and then the filtering assembly is folded, one end of the filtering assembly is driven by the mounting plate (17) to rotate relative to the rotating plate, and then the filtering assembly is twisted to crush the ammonium perchlorate remaining on the filtering assembly; The filtering assembly comprises a filter screen (15) and an expansion member; both ends of the filter screen (15) are connected with the expansion member, both ends of the expansion member are connected with connecting columns (26), and the connecting columns (26) are slidably arranged in the corresponding mounting plates (17); the two connecting columns (26) are away from each other, and the filtering assembly is unfolded; the two connecting columns (26) are close to each other, and the expansion assembly is folded; The expansion member comprises mounting rods (23) and elastic strips (29), the mounting rods (23) and the elastic strips (29) are both provided in plurality, and the mounting rods (23) and the elastic strips (29) are alternately arranged, two adjacent mounting rods (23) are connected through the elastic strip (29), and the mounting rod (23) and the elastic strip (29) are both fixedly connected with the filter screen (15); The driving member comprises a sliding block (22), the sliding block (22) is slidably arranged in the mounting plate (17), a limiting block (24) is slidably arranged on the sliding block (22), one end of the connecting column (26) extending into the mounting plate (17) is fixedly connected with an inclined surface block (25), and the limiting block (24) is provided with an inclined surface matched with the inclined surface block (25).

2. The ammonium perchlorate filtration and drying apparatus of claim 1, wherein: A lead screw (20) is rotatably arranged in the mounting plate (17), a third motor (19) is mounted in the mounting plate (17) and is drivingly connected with the lead screw (20), and the sliding block (22) is threadedly connected with the lead screw (20).

3. The ammonium perchlorate filtration and drying apparatus of claim 1, wherein: Two rotating plates are fixedly connected with a connecting shaft (14); the connecting shaft (14) is fixedly connected between the two rotating plates; the filtering assembly is provided with two, and the two filtering assemblies are arranged on the two sides of the connecting shaft (14).

4. The ammonium perchlorate filtration and drying apparatus of claim 3, wherein: A first motor (4) is fixedly installed on the drying box (3), an output shaft of the first motor (4) is connected with a driving wheel (13), one end of the connecting shaft (14) is connected with a driven wheel (11), and the driven wheel (11) and the driving wheel (13) are provided with a belt (12) therebetween.

5. The ammonium perchlorate filtration and drying apparatus of claim 1, wherein: The drying box (3) is installed on a fixed base (1), a fixed column (2) is installed on the fixed base (1), and the drying box (3) is connected with the fixed column (2).

6. The ammonium perchlorate filtration and drying apparatus of claim 1, wherein: The heating member is a heating layer (16), and the heating layer (16) is embeddedly installed in the side wall of the drying box (3).

7. A method for filtering and drying ammonium perchlorate, using the ammonium perchlorate filtering and drying device according to claim 1, characterized in that, The method comprises the following steps: S1, ammonium perchlorate is added into the drying box (3); S2, start the heating element, the heating element dries the ammonium perchlorate in the drying box (3); S3, make the rotating plate rotate, the rotating plate drives the mounting plate (17) to rotate, the mounting plate (17) drives the filtering assembly to rotate, the ammonium perchlorate is filtered, and the caked ammonium perchlorate is retained on the filtering assembly; S4, make the filtering assembly fold; S5, make one end of the filtering assembly rotate relative to the rotating plate through the mounting plate (17), so that the filtering assembly is twisted, and the caked ammonium perchlorate is crushed by extrusion.

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