Multi-stage phosphoric acid spray dryer

Abstract

The invention relates to the technical field of spray drying, in particular to a multistage phosphoric acid spray dryer. Comprising a drying tower; a cover plate is arranged at the upper end of the drying tower, hot air mechanisms are arranged on the cover plate and the drying tower, and a centrifugal spray head and a material blocking mechanism used for prolonging the falling time of phosphoric acid are rotationally installed in the drying tower. A phosphoric acid solution is atomized through the centrifugal spray head, the atomized phosphoric acid solution is dried in time, then the conical pipe is knocked through the knocking part to vibrate the conical pipe so as to promote falling of phosphoric acid powder and prevent the phosphoric acid powder from being attached, and then the crushed phosphoric acid powder is thrown out through centrifugal force to be dried again. Dehydration is enhanced while adhesion is prevented, so that the drying efficiency and quality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of spray drying, and particularly relates to a multi-stage phosphoric acid spray dryer. Background Art

[0002] A phosphoric acid spray dryer is a device used to convert liquid phosphoric acid or its solution into dry powder or granules, and is widely used in industries such as chemical industry, food, and pharmaceuticals; the working process of the phosphoric acid spray dryer is as follows: liquid phosphoric acid or its solution is transported to an atomizer by a pump, and a centrifugal atomizing head throws out the atomized liquid phosphoric acid. Subsequently, high-temperature hot air contacts the atomized droplets in the drying tower, and through heat conduction, water evaporates rapidly within a few seconds, and the droplets are dehydrated and solidified to form dry powder. The dried powder and waste gas enter a cyclone separator and a bag filter for gas-solid separation and collection.

[0003] However, the above processing process has the following problems: only by using a centrifugal spray head to throw out the atomized liquid phosphoric acid for drying, the thrown phosphoric acid directly falls, so that the atomized droplets only experience contact with high-temperature hot air once, and some larger droplets cannot be completely dehydrated in a short time, thus affecting the quality of the product; secondly, the phosphoric acid thrown out by the centrifugal spray head is easily attached to the inner wall of the drying tower, and it is difficult for the attached phosphoric acid to fall only by its own gravity after drying.

[0004] Therefore, the problems of incomplete drying of phosphoric acid and the atomized droplets that are easily attached to the inner wall of the drying tower and are not easily dropped from the inner wall of the drying tower after drying are technical problems that need to be solved by those skilled in the art. Summary of the Invention

[0005] In view of the above problems, embodiments of the present invention provide a multi-stage phosphoric acid spray dryer to solve the above-mentioned technical problems.

[0006] To achieve the above object, embodiments of the present invention provide the following technical solution: a multi-stage phosphoric acid spray dryer, including a drying tower; a cover plate is provided at the upper end of the drying tower, and a hot air mechanism is provided on both the cover plate and the drying tower. A centrifugal spray head and a baffle mechanism for extending the falling time of phosphoric acid are rotatably installed in the drying tower; wherein: the baffle mechanism includes a conical tube provided at the lower end of the cover plate, and a conical tube and a straight tube are sequentially arranged in the drying tower from top to bottom below the centrifugal spray head. The lower end of the conical tube is rotatably installed with a storage box, and discharge holes are evenly formed in the outer circumferential wall of the storage box along its circumference. A guide cone is fixedly installed on the inner bottom wall of the storage box, and a knocking part and a crushing part are provided on the storage box. A rotating shaft is coaxially and fixedly installed on the centrifugal spray head, and the lower end of the rotating shaft fixedly penetrates through the guide cone and the storage box; the knocking part includes hammers uniformly arranged along the circumference at the upper end of the storage box, and the hammers are also axially misaligned with the rotating shaft. The hammers rotate with the centrifugal spray head to knock the conical tube at a high frequency and the knocking points are constantly changing, so that the conical tube vibrates to assist in discharging materials.

[0007] The crushing part includes a grinding ring arranged in the storage box and cooperating with the material guiding cone. Under the action of the hot air blown by the upper hot air mechanism and the rotational centrifugal force of the storage box, the phosphoric acid powder passes between the grinding ring and the material guiding cone and is crushed, and is thrown out through the discharge hole to receive re-drying by the lower hot air mechanism.

[0008] As a preferred solution, the knocking part further includes a first shaft plate. The upper end of the storage box is rotatably installed with a first connecting rod through the first shaft plate, and the upper end of the storage box is rotatably installed with a second connecting rod located between two adjacent first connecting rods through a second shaft plate. The upper ends of the first connecting rod and the second connecting rod are both fixedly installed with knocking hammers through flexible columns. A driving part for driving the first connecting rod and the second connecting rod to swing reciprocally is jointly arranged on the storage box and the conical tube. The knocking hammer on the second connecting rod is lower than the knocking hammer on the first connecting rod.

[0009] As a preferred solution, the driving part includes waist-shaped grooves. The lower ends of the first connecting rod and the second connecting rod are both provided with waist-shaped grooves. The upper end of the storage box is slidably installed with shaft seats corresponding to the first connecting rod and the second connecting rod along its radial direction. A roller shaft that slidably penetrates the corresponding waist-shaped groove is fixedly installed on the shaft seat. One end of the shaft seat close to the center of the storage box is fixedly installed with a connecting plate. A guiding part for guiding the reciprocating movement of the connecting plate is arranged between the conical tube and the connecting plate.

[0010] As a preferred solution, a first material blocking tube is uniformly and fixedly installed on the inner wall of the straight tube along its axial direction. The inner wall of the straight tube is fixedly installed with a second material blocking tube located below the first material blocking tube through a support column. The first material blocking tube is a frustum-shaped structure with an inner diameter at the upper end larger than that at the lower end. A material discharging hole is opened in the middle of the lower end of the first material blocking tube. The second material blocking tube is a frustum-shaped structure with an inner diameter at the upper end smaller than that at the lower end. The upper end of the second material blocking tube is rotatably connected to the rotating shaft.

[0011] As a preferred solution, the hot air mechanism includes a through hole. A through hole is opened in the middle of the cover plate. The centrifugal spray head is coaxial with the through hole and the through hole is located outside the centrifugal spray head. A hot air cylinder is fixedly installed on the upper end of the cover plate. A through hole coaxial with the through hole is opened on the hot air cylinder. The inner cavity of the hot air cylinder is communicated with the through hole. Air pipes are uniformly and obliquely installed along the circumferential direction of the drying tower above the straight tube. An annular tube communicated with the air pipes is fixedly installed on the outer wall of the drying tower.

[0012] As a preferred solution, retaining rings are fixedly installed at positions corresponding to the conical tube and the straight tube on the inner wall of the drying tower. Limiting grooves are uniformly opened along the circumferential direction at the upper ends of the retaining rings. Limiting blocks corresponding to the limiting grooves are fixedly installed on the conical tube and the straight tube. And the inner diameter of the retaining ring located above is smaller than the outer diameter of the straight tube.

[0013] As a preferred solution, the grinding ring is fixedly installed on the lower end face of the conical tube. The inner ring surface of the grinding ring is set as an inclined grinding surface, and the gap between the inclined grinding surface and the outer wall of the material guiding cone gradually decreases from top to bottom.

[0014] As a preferred solution, the guiding member includes an annular plate. The annular plate is fixedly installed on the outer wall of the lower end of the conical tube. A wave groove is formed along the circumference of the lower end of the annular plate, and a guide post that is slidably matched with the wave groove is fixedly installed at the upper end of the connecting plate.

[0015] As a preferred solution, a fixing plate is fixedly installed at the upper end of the hot air cylinder. The upper end of the centrifugal spray head is rotatably installed at the lower end of the fixing plate, and the upper end of the rotating shaft rotatably penetrates through the fixing plate.

[0016] One or more of the above technical solutions in the embodiments of the present invention have at least one of the following technical effects: First, the present invention atomizes the phosphoric acid solution through the centrifugal spray head and immediately dries the atomized phosphoric acid solution. Then, the conical tube is vibrated by the knocking part to promote the falling of the phosphoric acid powder and prevent the phosphoric acid powder from adhering. Then, the broken phosphoric acid powder is thrown out by centrifugal force to be dried again, preventing adhesion and strengthening dehydration at the same time, so as to improve the drying efficiency and quality.

[0017] Second, the present invention adopts the synergistic effect of the layered hot air system and the multi-stage material baffle design to solve the limitations of traditional single-stage drying. The hot air cylinder at the top directly conducts preliminary drying on the atomized droplets through the through hole, while the secondary hot air system composed of the annular tube and the inclined air duct obliquely sends high-temperature air flow from the side wall of the drying tower to form staggered convection, forcing the phosphoric acid powder to repeatedly collide and stay in the multi-stage drying cavity composed of the conical tube and the straight tube, so as to improve the drying quality.

[0018] Third, the present invention solves the low-efficiency problem of traditional gravity-dependent shedding through the design of mechanical vibration to prevent adhesion, forced crushing, and re-drying. In terms of vibration anti-adhesion, the conical tube is vibrated during preliminary drying through the linkage of a single drive and a mechanical structure, so as to effectively peel off the phosphoric acid powder adhering to the inner wall of the conical tube, and improve the feeding speed and utilization rate of the phosphoric acid powder.

[0019] Fourth, in the present invention, the hammer is axially misaligned on the rotating shaft to form several misaligned knocking points, which can knock on multiple positions of the conical tube, improve the vibration effect of the conical tube, and at the same time make the conical tube receive a more uniform knocking force, so that the powder layers at different heights can be effectively shaken off, reducing the stacking gradient of the powder in the axial direction of the conical tube, expanding the coverage range of effective knocking, and improving the overall powder removal rate. In addition, the knocking points are continuously changed by the continuous circumferential movement of the hammer, and the knocking area is dynamically adjusted to prevent the powder from re-adhering at specific positions.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Brief Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the provided drawings.

[0022] Figure 1 It is a schematic three-dimensional structure diagram of the present invention.

[0023] Figure 2 It is a partial structure sectional view of the present invention.

[0024] Figure 3 is Figure 2 an enlarged view of the structure at A in

[0025] Figure 4 It is a schematic structure diagram of the knocking part of the present invention.

[0026] Figure 5 It is a schematic structure diagram of the driving part of the present invention.

[0027] Figure 6 It is a schematic structure diagram of the wave groove of the present invention.

[0028] Figure 7 It is a schematic structure diagram of the first material blocking pipe and the second material blocking pipe of the present invention.

[0029] Reference numerals: 10, drying tower; 11, cover plate; 12, centrifugal spray head; 13, rotating shaft; 14, fixing plate; 2, material blocking mechanism; 20, conical pipe; 200, retaining ring; 201, limiting block; 21, straight pipe; 210, first material blocking pipe; 211, second material blocking pipe; 23, storage box; 24, guiding cone; 25, knocking part; 250, first connecting rod; 251, flexible column; 252, hammer; 253, second connecting rod; 4, driving part; 40, shaft seat; 41, connecting plate; 5, guiding part; 50, ring plate; 51, wave groove; 52, guiding column; 26, crushing part; 260, grinding ring; 3, hot air mechanism; 30, through hole; 31, hot air cylinder; 32, air duct; 33, annular pipe. Detailed Embodiments

[0030] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0031] As Figure 1 and Figure 2 shown, a multi-stage phosphoric acid spray dryer includes a drying tower 10; a cover plate 11 is detachably installed at the upper end of the drying tower 10, and hot air mechanisms 3 are provided on both the cover plate 11 and the drying tower 10. A centrifugal spray head 12 and a material blocking mechanism 2 for extending the falling time of phosphoric acid are rotatably installed in the drying tower 10, and a rotating shaft 13 is coaxially and fixedly installed on the centrifugal spray head 12.

[0032] As Figure 1 , Figure 2 , Figure 3 and Figure 4 shown, the material blocking mechanism 2 includes a conical tube 20 detachably installed at the lower end of the cover plate 11. In the drying tower 10, a conical tube 20 and a straight tube 21 are sequentially arranged from top to bottom below the centrifugal spray head 12. The lower end of the conical tube 20 is rotatably installed inside the upper side of the straight tube 21. The outer ring wall of the storage box 23 is evenly provided with discharge holes along its circumferential direction. A guide cone 24 is fixedly installed on the inner bottom wall of the storage box 23. The lower end of the rotating shaft 13 fixedly penetrates through the guide cone 24 and the storage box 23. A knocking part 25 and a crushing part 26 are provided on the storage box 23.

[0033] As Figure 2 and Figure 4 shown, the knocking part 25 includes hammers 252 evenly arranged along the circumferential direction at the upper end of the storage box 23, and the hammers 252 are also axially offset from the rotating shaft 13. The hammers 252 rotate with the centrifugal spray head 12 and knock on the outer wall of the conical tube 20 at a high frequency, causing the conical tube 20 to vibrate to assist in discharging materials.

[0034] As Figure 2 , Figure 3 and Figure 4 shown, the crushing part 26 includes a grinding ring 260 arranged in the storage box 23 and cooperating with the guide cone 24. The dry phosphoric acid passes between the grinding ring 260 and the guide cone 24 through the blowing of the hot air mechanism 3 and the rotation of the storage box 23, is crushed, and is thrown out through the discharge holes for re-drying.

[0035] As Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, at the positions on the inner wall of the drying tower 10 corresponding to the conical tube 20 and the straight tube 21 one by one, retaining rings 200 are fixedly installed. At the upper end of the retaining ring 200, limiting grooves are evenly formed along its circumferential direction. On the conical tube 20 and the straight tube 21, limiting blocks 201 fixedly installed corresponding to the limiting grooves one by one are provided, and the inner diameter of the retaining ring 200 located above is smaller than the outer diameter of the straight tube 21.

[0036] During specific operation, first, the worker installs the straight tube 21 into the drying tower 10 manually, and then installs the cover plate 11 onto the upper end of the drying tower 10. The straight tube 21 abuts against the lower retaining ring 200, and the retaining ring 200 supports the straight tube 21. Moreover, the limiting block 201 on the straight tube 21 is clamped into the limiting groove on the lower retaining ring 200 to limit the rotation of the straight tube 21. The conical tube 20 abuts against the upper retaining ring 200, and at the same time, the limiting block 201 on the conical tube 20 is clamped into the limiting groove of the upper retaining ring 200, thereby restricting the downward movement and rotation of the conical tube 20. At the same time, the lower end of the rotating shaft 13 is inserted into the shaft bracket arranged in the drying tower 10, and subsequently, the rotating shaft 13 can rotate on the shaft bracket.

[0037] After the cover plate 11 is fixed to the upper end of the drying tower 10, the centrifugal spray head 12 rotates at a high speed. At the same time, an external conveyor transports the phosphoric acid solution into the centrifugal spray head 12. Along with the rotation of the centrifugal spray head 12, the phosphoric acid solution is thrown out in an atomized state. At the same time, the hot air mechanism 3 transports hot air into the drying tower 10. The thrown-out phosphoric acid solution is dried into crystal powder by the hot air. And part of the solution that fails to be dried in time flows on the inner wall of the conical tube 20 and is finally dried by the hot air. During the drying process, the hammer 252 reciprocally knocks on the conical tube 20 at a high frequency, causing the conical tube 20 to vibrate. As a result, the dried phosphoric acid crystals on the conical tube 20 break away from the conical tube 20 and fall towards the storage box 23, and through the cooperation of the grinding ring 260 and the guiding cone 24, the phosphoric acid crystals are broken into appropriate sizes. The appropriately sized phosphoric acid crystals are thrown out from the discharge hole on the storage box 23 and dried again to remove the excess moisture in the phosphoric acid crystals.

[0038] As Figure 1 and Figure 2 shown, the hot air mechanism 3 includes a through hole 30. A through hole 30 is formed in the middle of the cover plate 11. The centrifugal spray head 12 and the through hole 30 are coaxial, and the through hole 30 is located outside the centrifugal spray head 12. A hot air cylinder 31 is fixedly installed at the upper end of the cover plate 11. A through hole coaxial with the through hole 30 is formed in the hot air cylinder 31. The inner cavity of the hot air cylinder 31 is communicated with the through hole 30. Along the circumferential direction of the drying tower 10 and above the straight tube 21, air ducts 32 are evenly and obliquely installed. An annular tube 33 communicated with the air ducts 32 is fixedly installed on the outer wall of the drying tower 10.

[0039] As Figure 2As shown, a fixing plate 14 is fixedly installed at the upper end of the hot air blower 31. The upper end of the centrifugal spray head 12 is rotatably installed at the lower end of the fixing plate 14, and the upper end of the rotating shaft 13 rotatably penetrates through the fixing plate 14.

[0040] As Figure 2 , Figure 4 and Figure 5 As shown, the knocking part 25 further includes a first shaft plate. A first connecting rod 250 is rotatably installed at the upper end of the storage box 23 through the first shaft plate. A hammer 252 is fixedly installed at the upper end of the first connecting rod 250 through a flexible column 251. A second connecting rod 253 located between two adjacent first connecting rods 250 is rotatably installed at the upper end of the storage box 23 through a second shaft plate. A hammer 252 is also fixedly installed at the upper end of the second connecting rod 253 through a flexible column 251. The height of the hammer 252 on the second connecting rod 253 is lower than that of the hammer 252 on the first connecting rod 250. The hammers 252 at different heights cooperate to form knocking points with a staggered layout, which can knock on multiple positions of the conical tube 20 to improve the vibration effect of the conical tube 20. At the same time, the knocking force received by the conical tube 20 is more evenly distributed, avoiding local fatigue caused by repeated knocking at a single height, enabling powder layers at different heights to be effectively shaken off, expanding the effective knocking coverage range, improving the overall powder removal rate, and reducing the powder accumulation gradient in the axial direction of the conical tube 20. A driving member 4 for driving the first connecting rod 250 and the second connecting rod 253 to swing reciprocally is commonly provided on the storage box 23 and the conical tube 20.

[0041] During specific operation, an external hot air system is communicated with the hot air pipe 32 and the annular pipe 33, so that the hot air in the hot air pipe 32 blows towards the phosphoric acid solution ejected by the centrifugal spray head 12 through the through hole 30, enabling the phosphoric acid solution to be dried, while the hot air in the annular pipe 33 blows towards the straight tube 21 through the air pipe 32 to dry the phosphoric acid powder.

[0042] A motor (not shown in the figure) is fixedly installed at the upper end of the fixing plate 14 through a bracket. A liquid injection pipe communicated with the centrifugal spray head 12 is connected to the fixing plate 14. The output shaft of the motor is connected to the rotating shaft 13 and drives the rotating shaft 13 to rotate. The rotating shaft 13 drives the centrifugal spray head 12 to rotate at a high speed, and the centrifugal spray head 12 sprays out the phosphoric acid solution. At the same time, the rotation of the rotating shaft 13 drives the storage box 23 to rotate, and the storage box 23 drives the lower ends of the first connecting rod 250 and the second connecting rod 253 to swing reciprocally through the driving member 4. The first connecting rod 250 and the second connecting rod 253 drive the corresponding hammers 252 to reciprocally knock on the conical tube 20 through the flexible columns 251, causing the conical tube 20 to vibrate to assist in discharging materials. During the process of the hammer 252 reciprocally knocking on the conical tube 20, the flexible column 251 can play a role in buffering and vibration transmission, extend the contact time through elastic deformation, enhance the vibration transmission efficiency, and make the powder more likely to fall off.

[0043] As Figure 2 ,Figure 4 and Figure 5 As shown in Figure 5 , the driving member 4 includes an oblong slot. The lower ends of the first connecting rod 250 and the second connecting rod 253 are both provided with oblong slots. Along the radial direction of the upper end of the storage box 23, shaft seats 40 corresponding to the first connecting rod 250 and the second connecting rod 253 are slidably installed. Roller shafts that slidably penetrate the corresponding oblong slots are fixedly installed on the shaft seats 40. A connecting plate 41 is fixedly installed at one end of the shaft seat 40 close to the center of the storage box 23. A guiding member 5 for guiding the reciprocating movement of the connecting plate 41 is provided between the conical tube 20 and the connecting plate 41.

[0044] As Figure 2 、 Figure 4 、 Figure 5 and Figure 6 As shown in Figure 5 and Figure 6 , the guiding member 5 includes an annular plate 50. The annular plate 50 is fixedly installed on the outer wall of the lower end of the conical tube 20. A wave slot 51 is provided along the circumferential direction of the lower end of the annular plate 50. A guide post 52 that is slidably engaged with the wave slot 51 is fixedly installed at the upper end of the connecting plate 41.

[0045] As Figure 2 and Figure 3 As shown in Figure 2 and Figure 3 , the grinding ring 260 is fixedly installed on the lower end surface of the conical tube 20. The inner ring surface of the grinding ring 260 is set as an inclined grinding surface, and the gap between the inclined grinding surface and the outer wall of the material guiding cone 24 gradually decreases from top to bottom.

[0046] As Figure 2 and Figure 7 As shown in Figure 2 and Figure 7 , a first baffle tube 210 is uniformly and fixedly installed on the inner wall of the straight tube 21 along its axial direction. A second baffle tube 211 located below the first baffle tube 210 is fixedly installed on the inner wall of the straight tube 21 through a support column. The first baffle tube 210 is a frustum structure with an inner diameter at the upper end larger than that at the lower end. A material discharging hole is provided in the middle of the lower end of the first baffle tube 210. The second baffle tube 211 is a frustum structure with an inner diameter at the upper end smaller than that at the lower end. The upper end of the second baffle tube 211 is rotatably connected to the rotating shaft 13.

[0047] As Figures 2 to 7As shown, during specific operation, the rotation of the rotating shaft 13 drives the processing storage box 23 to rotate. During the rotation of the storage box 23, the guide post 52 is driven to slide in the wave groove 51. The wave groove 51 reciprocally pushes the shaft seat 40 to move radially through the guide post 52 and the connecting plate 41. The shaft seat 40 drives the lower end of the corresponding connecting rod one 250 or connecting rod two 253 to swing reciprocally through the cooperation of the roller shaft and the waist-shaped groove. Since the connecting rod one 250 and the connecting rod two 253 are essentially a lever structure, the small swing of the lower end of the connecting rod one 250 or the connecting rod two 253 can be converted into a larger displacement and acceleration at its upper end. Furthermore, the connecting rod one 250 and the connecting rod two 253 drive the hammer 252 to perform reciprocating high-frequency knocking on the conical tube 20. The vibration generated by the knocking causes the phosphoric acid powder on the inner wall of the conical tube 20 to fall off and drop into the crushing part 26. The rotation of the storage box 23 also causes the hammer 252 to continuously move circumferentially, making the knocking points constantly change, avoiding local wear of the conical tube 20 caused by long-term knocking at a fixed position. By dynamically adjusting the knocking area, it prevents the powder from reattaching at specific positions, and the vibration of the flexible column 251 is more conducive to enhancing the knocking-off effect.

[0048] The rotation of the rotating shaft 13 drives the storage box 23 and the feeding cone 24 to rotate synchronously. The phosphoric acid powder drops between the feeding cone 24 and the grinding ring 260. Under the blowing of the hot air in the through hole 30 and the centrifugal force generated by the rotation of the storage box 23, the phosphoric acid powder enters between the feeding cone 24 and the grinding ring 260. The feeding cone 24 and the grinding ring 260 cooperate to grind the passing phosphoric acid powder. The ground phosphoric acid powder is thrown out from the discharge hole with the rotation of the storage box 23 and is dried again by the hot air blown out from the hot air pipe 32 to remove excess moisture. The thrown phosphoric acid powder then falls along the inclined inner wall of the baffle pipe one 210 and drops from the feeding hole to the inclined outer wall of the baffle pipe two 211, and then falls along the inclined outer wall of the baffle pipe two 211. Finally, it enters the external separator connected to the lower end of the drying tower 10 from the lower end of the drying tower 10, and the dry powder and the waste gas are separated by the external separator. By alternately arranging a number of baffle pipes one 210 and baffle pipes two 211, the falling path of the dry powder is extended, thereby increasing the falling time of the dry powder in the drying tower 10 to ensure the drying effect of the phosphoric acid powder.

[0049] It should be noted that when the storage box 23 rotates, since the connecting rod one 250 and the connecting rod two 253 are not fixedly connected, their movements will lag behind the storage box 23 relatively. The elasticity of the flexible column 251 may also cause the movement of the hammer 252 to lag, but the movement lag is not necessarily a disadvantage. Rational utilization can form a vibration superposition effect, and multi-frequency vibration can enhance powder removal. The non-fully synchronous movement of the hammer 252 may randomize the vibration wave and enhance the knocking-off effect.

[0050] To avoid excessive lag, the following improvement measures can be taken: adjust the stiffness of the flexible column 251, select a flexible column 251 with medium stiffness to balance the buffering and knocking forces; adjust the mass of the hammer 252, and lightweight and high-strength materials such as titanium alloy can be used to reduce inertia; adjust the rotation speed of the rotating shaft 13 to shorten the movement cycle and reduce the lag cumulative effect; reduce the frictional resistance, and lubricants can be added or ball bearings can be installed at the waist-shaped groove and the roller shaft, and at the guide post 52 and the wavy groove 51.

[0051] None of the above improvement measures require creative labor. Selecting a flexible column 251 with medium stiffness is a conventional design in material mechanics. Adding lubricants or ball bearings is a common means in machinery to reduce frictional resistance. Using lightweight and high-strength materials is a common means for lightweighting. Adjusting the rotation speed is a common process parameter adjustment.

[0052] Of course, torsion springs (not shown in the figure) can also be installed at the first shaft plate and the first connecting rod 250, and at the second shaft plate and the second connecting rod 253 to assist the hammer 252 to quickly reset and control the lag phase difference.

[0053] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0054] In addition, the terms "first", "second", "No. 1", "No. 2" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", "No. 1", "No. 2" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0055] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "connected", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0056] The embodiments of the specific implementation manners are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A multi-stage phosphoric acid spray dryer, comprising a drying tower; characterized in that: A cover plate is provided at the upper end of the drying tower. Hot air mechanisms are provided on both the cover plate and the drying tower. An atomizing head and a material blocking mechanism for prolonging the falling time of phosphoric acid are rotatably installed in the drying tower. Among them: The material blocking mechanism includes a conical tube provided at the lower end of the cover plate. A conical tube and a straight tube are sequentially arranged in the drying tower from top to bottom and are located below the atomizing head. The lower end of the conical tube is rotatably installed with a storage box. The outer ring wall of the storage box is evenly provided with discharge holes along its circumference. A guiding cone is fixedly installed on the inner bottom wall of the storage box. A knocking part and a crushing part are provided on the storage box. A rotating shaft is coaxially and fixedly installed on the atomizing head. The lower end of the rotating shaft fixedly penetrates through the guiding cone and the storage box. The knocking part includes hammers evenly arranged along the circumference at the upper end of the storage box, and the hammers are also axially offset from the rotating shaft. The hammers rotate with the atomizing head to knock the conical tube at a high frequency and the knocking points are constantly changing, causing the conical tube to vibrate to assist in discharging materials. The crushing part includes a grinding ring arranged in the storage box and cooperating with the guiding cone. The phosphoric acid powder passes between the grinding ring and the guiding cone under the action of the hot air blown by the upper hot air mechanism and the centrifugal force of the rotating storage box, is crushed, and is thrown out through the discharge holes to receive re-drying by the lower hot air mechanism.

2. The multi-stage phosphoric acid spray dryer according to claim 1, wherein: The knocking part further includes a first shaft plate. The upper end of the storage box is rotatably installed with a first connecting rod through the first shaft plate. The upper end of the storage box is rotatably installed with a second connecting rod located between two adjacent first connecting rods through a second shaft plate. Hammers are fixedly installed at the upper ends of the first connecting rod and the second connecting rod through flexible columns. A driving part for driving the first connecting rod and the second connecting rod to swing reciprocally is jointly provided on the storage box and the conical tube.

3. The multi-stage phosphoric acid spray dryer according to claim 2, characterized in that: The driving part includes kidney-shaped grooves. The lower ends of the first connecting rod and the second connecting rod are both provided with kidney-shaped grooves. The upper end of the storage box is slidably installed along its radial direction with shaft seats corresponding to the first connecting rod and the second connecting rod one by one. A roller shaft slidably penetrating through the corresponding kidney-shaped groove is fixedly installed on the shaft seat. A connecting plate is fixedly installed at one end of the shaft seat close to the center of the storage box. A guiding part for guiding the connecting plate to move reciprocally is provided between the conical tube and the connecting plate.

4. A multi-stage phosphoric acid spray dryer according to claim 1, characterized in that: A first material blocking tube is evenly and fixedly installed on the inner ring wall of the straight tube along its axial direction. A second material blocking tube located below the first material blocking tube is fixedly installed on the inner ring wall of the straight tube through a support column. The first material blocking tube is a frustum-shaped structure with an inner diameter at the upper end larger than that at the lower end. A material discharging hole is provided in the middle of the lower end of the first material blocking tube. The second material blocking tube is a frustum-shaped structure with an inner diameter at the upper end smaller than that at the lower end. The upper end of the second material blocking tube is rotatably connected to the rotating shaft.

5. A multi-stage phosphoric acid spray dryer according to claim 1, characterized in that: The hot air mechanism includes a through hole. A through hole is provided in the middle of the cover plate. The atomizing head is coaxial with the through hole and the through hole is located outside the atomizing head. A hot air cylinder is fixedly installed at the upper end of the cover plate. A through hole coaxial with the through hole is provided on the hot air cylinder. The inner cavity of the hot air cylinder is communicated with the through hole. Air pipes are evenly and obliquely installed on the drying tower along its circumference and are located above the straight tube. An annular tube communicated with the air pipes is fixedly installed on the outer ring wall of the drying tower.

6. The multi-stage phosphoric acid spray dryer according to claim 1, wherein: On the inner wall of the drying tower, retaining rings are fixedly installed at positions corresponding to the conical pipe and the straight pipe one by one. Limiting grooves are evenly formed along the circumferential direction at the upper end of the retaining ring. Limiting blocks corresponding to the limiting grooves one by one are fixedly installed on the conical pipe and the straight pipe, and the inner diameter of the retaining ring located above is smaller than the outer diameter of the straight pipe.

7. A multi-stage phosphoric acid spray dryer according to claim 1, characterized in that: The grinding ring is fixedly installed on the lower end face of the conical pipe. The inner ring surface of the grinding ring is set as an inclined grinding surface, and the gap between the inclined grinding surface and the outer wall of the material guiding cone gradually decreases from top to bottom.

8. The multi-stage phosphoric acid spray dryer according to claim 3, wherein: The guiding member includes an annular plate. The annular plate is fixedly installed on the outer wall of the lower end of the conical pipe. A wave groove is formed along the circumferential direction at the lower end of the annular plate. A guide post that is slidably engaged with the wave groove is fixedly installed at the upper end of the connecting plate.

9. The multi-stage phosphoric acid spray dryer according to claim 5, characterized in that: A fixing plate is fixedly installed at the upper end of the hot air cylinder. The upper end of the centrifugal spray head is rotatably installed at the lower end of the fixing plate, and the upper end of the rotating shaft rotatably penetrates through the fixing plate.

10. A multi-stage phosphoric acid spray dryer according to claim 2, characterized in that: The height of the hammer on the second connecting rod is lower than that of the hammer on the first connecting rod.

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