Pressurized spray drying system for producing anhydrous calcium hydrogen phosphate

Abstract

The invention discloses a pressurized spray drying system for producing anhydrous calcium hydrogen phosphate, and relates to the field of anhydrous calcium hydrogen phosphate production drying, the pressurized spray drying system comprises a shell, the shell is provided with an upper opening and a lower opening, the lower opening fixes a discharge cylinder, the tail end of the discharge cylinder is provided with a fixed nozzle, and the shell is rotatably connected with symmetrically distributed filter plates near the upper opening. According to the invention, the V-shaped filter plate is combined with the slide column and slide groove linkage vibration design, impurities in filter holes are periodically removed, the filter efficiency is improved, and phosphate particle blockage is effectively avoided; coarse materials are crushed at a high speed through the grinding roller, fine materials are forced to flow back to the cavity through the first spiral pressurizing piece, and material liquid circulation treatment and efficient resource utilization are achieved. The double-shaft motor drives the second pressurizing piece to form a centrifugal pressurizing cavity, the feed liquid pressure is increased, it is ensured that the atomization particle size is qualified, the discharging resistance is reduced, and the drying efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of production and drying of anhydrous calcium hydrogen phosphate, and particularly to a pressurized spray drying system for producing anhydrous calcium hydrogen phosphate. Background Art

[0002] Anhydrous calcium hydrogen phosphate ( ) is an important inorganic chemical product and is widely used in fields such as food, medicine, feed, and toothpaste additives. Its physical and chemical properties (such as fluidity, solubility, particle uniformity, etc.) have a significant impact on the performance of end products. In the production process, the drying link is one of the key steps determining product quality.

[0003] In recent years, spray drying technology has gradually become the mainstream process for drying anhydrous calcium hydrogen phosphate due to its advantages such as rapid evaporation, continuous production, and controllable product particle size. This technology disperses the feed liquid into micron-sized droplets through an atomizing device, makes instant contact with the heat medium to complete heat and mass transfer, and finally obtains dry powder. However, in the actual production of anhydrous calcium hydrogen phosphate, undissolved phosphate particles or impurities in the raw material liquid are likely to deposit at the nozzle, and coupled with the large flow resistance of high-viscosity materials, it leads to uneven atomization particle size distribution, spray cone angle deviation, and even causes shutdown failures.

[0004] Based on the above situation, there is an urgent need for a pressurized spray drying system for producing anhydrous calcium hydrogen phosphate. Summary of the Invention

[0005] In order to overcome the drawback of easy blockage of the nozzle in the existing spray drying system for anhydrous calcium hydrogen phosphate, the present invention provides a pressurized spray drying system for producing anhydrous calcium hydrogen phosphate.

[0006] A pressurized spray drying system for producing anhydrous calcium hydrogen phosphate includes a housing with upper and lower openings. The lower opening is fixedly connected to a discharge cylinder, and a fixed nozzle is installed at the end of the discharge cylinder. The housing is rotatably connected near the upper opening with symmetrically distributed filter plates. The two filter plates are inclined inward. Branch ports are opened on both sides of the housing corresponding to the inclined ends of the filter plates. A grinding cylinder is fixedly connected to one side of the housing near the branch ports. A double-shaft motor is installed on the outside of the housing. Its upper output shaft penetrates through the grinding cylinder and is connected to a grinding roller through a coupling. Drain pipes are symmetrically connected to both sides of the grinding cylinder, and the outlets of the symmetrically distributed drain pipes are both located in a double-square cavity.

[0007] As an improvement of the above solution, a number of first booster pieces are also connected to the upper output shaft of the double-shaft motor.

[0008] As an improvement to the above solution, a convex block is fixedly connected to the end of the grinding roller, on which there is an inclined surface. On one side of the outer shell close to the convex block, symmetrically distributed first springs are fixedly connected. A lifting plate is connected between the symmetrically distributed first springs. The grinding roller passes through the lifting plate and has a clearance fit. Symmetric chutes are provided on the lifting plate. On one side of the symmetrically distributed filter plates close to the branch port, symmetrically distributed sliding columns are provided, and the sliding columns are arranged in the chutes.

[0009] As an improvement to the above solution, a convex column is provided on the inner side of the top wall of the lifting plate, and the convex column is in extrusion fit with the inclined surface of the convex block.

[0010] As an improvement to the above solution, the output shaft on the lower side of the double-shaft motor is connected to a connecting shaft through a coupling, and several second boosting sheets are welded on the connecting shaft.

[0011] As an improvement to the above solution, a rotary nozzle is rotatably connected to the outside of the discharge cylinder. A plurality of second liquid discharge ports are circumferentially opened on its inner wall, and the second liquid discharge ports are circumferentially equidistributed. A plurality of first liquid discharge ports are circumferentially opened on the inner wall of the discharge cylinder, and the first liquid discharge ports and the second liquid discharge ports are staggered.

[0012] As an improvement to the above solution, a pressure relief cylinder is fixedly connected to the discharge cylinder. A driving rod is slidably connected in the pressure relief cylinder. A second spring is connected between the driving rod and the pressure relief cylinder, and the second spring is wound around the driving rod. A bent guide groove is opened inside the rotary nozzle, and the driving rod slides in the guide groove through a ball bearing provided at the end.

[0013] As an improvement to the above solution, an annular light belt is installed on the outside of the fixed nozzle.

[0014] The present invention has the following advantages: The present invention adopts a "V"-shaped filter plate combined with a linkage vibration design of sliding columns and chutes to periodically remove impurities in the filter holes, improve the filtration efficiency, and effectively avoid the blockage of phosphate particles; the coarse material is crushed at high speed by the grinding roller, and the fine material is forced to flow back to the cavity by the spiral first boosting sheet to realize the cyclic treatment of the material liquid and the efficient utilization of resources; the double-shaft motor drives the second boosting sheet to form a centrifugal boosting cavity, which improves the pressure of the material liquid, ensures that the atomization particle size is qualified and reduces the discharge resistance, and improves the drying efficiency.

[0015] The present invention realizes precise regulation through a pressure driving mechanism. When the pressure in the discharge cylinder exceeds the threshold value, the driving rod moves downward to drive the rotary nozzle to rotate, and the spiral trajectory of the bent guide groove is used to dynamically align the liquid discharge ports, synchronously matching the spraying flow rate of the fixed nozzle, ensuring that the atomization particle size is uniform, and avoiding nozzle blockage; the annular light belt realizes real-time visual monitoring of the atomization state through the light scattering effect, and helps to quickly judge the atomization uniformity and operating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-dimensional structural schematic diagram of the present invention.

[0017] Figure 2 This is a sectional view of the three-dimensional structure of the present invention.

[0018] Figure 3 This is a sectional view of the three-dimensional structure of components such as the biaxial motor, fixed nozzle, and grinding roller of the present invention.

[0019] Figure 4 This is a sectional view of the three-dimensional structure of components such as the bump, lifting plate, and first spring of the present invention.

[0020] Figure 5 This is a schematic diagram of the three-dimensional structure of components such as the filter plate, bump, and lifting plate of the present invention.

[0021] Figure 6 This is a sectional view of the three-dimensional structure of the biaxial motor, connecting shaft, and second pressure-increasing piece of the present invention.

[0022] Figure 7 This is a sectional view of the three-dimensional structure of components such as the rotary nozzle, drive rod, and second spring of the present invention.

[0023] Figure 8 This is a schematic diagram of the three-dimensional structure of the rotary nozzle and drive rod of the present invention.

[0024] Figure 9 This is a schematic diagram of the three-dimensional structure of the fixed nozzle and annular light belt of the present invention.

[0025] In the reference numerals: 101 - housing, 1011 - discharge cylinder, 102 - filter plate, 1021 - sliding column, 103 - biaxial motor, 104 - fixed nozzle, 105 - grinding roller, 106 - first pressure-increasing piece, 107 - drain pipe, 108 - grinding cylinder, 109 - branch port, 201 - bump, 202 - lifting plate, 203 - first spring, 301 - connecting shaft, 302 - second pressure-increasing piece, 401 - first drain port, 402 - rotary nozzle, 4021 - second drain port, 403 - guide groove, 404 - drive rod, 405 - second spring, 406 - pressure relief cylinder, 501 - annular light belt. Detailed implementation manners

[0026] The present invention will be further described below in conjunction with the embodiments shown in the drawings.

[0027] Embodiment 1: A pressurized spray drying system for producing anhydrous calcium hydrogen phosphate, as Figures 1 - 3As shown in the figure, it includes a housing 101. The housing 101 is provided with openings at both the upper and lower ends. The upper opening is connected to a feeding pipe to introduce the liquid material, and the lower opening is fixedly connected to a discharging cylinder 1011. A fixed nozzle 104 is installed at the end of the discharging cylinder 1011 for atomizing the liquid material. There is a double-loop cavity inside the housing 101. Through double-channel feeding, the housing 101 is rotatably connected with symmetrically distributed filter plates 102 near the upper opening. The two filter plates 102 are inclined inward to form a "V"-shaped filtering surface, which can intercept large-particle impurities in the raw liquid material and cause the unfiltered coarse material to flow to both sides by gravity.

[0028] Branch ports 109 are opened on both sides of the housing 101 corresponding to the inclined ends of the filter plates 102. A grinding cylinder 108 is fixedly connected to one side of the housing 101 near the branch ports 109. The coarse material enters the grinding cylinder 108 through the branch ports 109. A double-shaft motor 103 is installed on the outer side of the housing 101. Its upper output shaft penetrates through the grinding cylinder 108 and is connected to a grinding roller 105 through a coupling. The double-shaft motor 103 drives the grinding roller to rotate at a high speed to perform secondary crushing and homogenization treatment on the coarse material. Drain pipes 107 are symmetrically connected to both sides of the grinding cylinder 108. The outlets of the symmetrically distributed drain pipes 107 are both located inside the double-loop cavity. The treated fine material flows back into the double-loop cavity through the drain pipes 107, mixes with the main material flow, and then enters the discharging cylinder 1011.

[0029] As Figure 3 shown, several first booster vanes 106 are also connected to the upper output shaft of the double-shaft motor 103. The first booster vanes 106 are spiral fan-shaped blades, which are equidistantly distributed along the axial direction of the output shaft. The blade inclination angle is 15° - 25°. The material is selected from 316L stainless steel or tungsten carbide coating, which has both wear resistance and corrosion resistance. The gap between the outer edge of the blade and the inner wall of the grinding cylinder 108 is 1 - 3 mm to ensure that there is no friction with the cylinder wall during high-speed rotation, and at the same time, a centrifugal boosting effect is formed. When the ground fine material accumulates at the bottom of the grinding cylinder 108, the first booster vanes 106 generate centrifugal force through rotation, and throw the material tangentially along the spiral blade towards the inlet of the drain pipe 107, forming a local pressure gradient to forcibly push the liquid material into the double-loop cavity quickly.

[0030] As Figure 4 and Figure 5 shown, a convex block 201 is fixedly connected to the end of the grinding roller 105, and it has an inclined surface. Symmetrically distributed first springs 203 are fixedly connected to one side of the housing 101 near the convex block 201. A lifting plate 202 is connected between the symmetrically distributed first springs 203. The grinding roller 105 passes through the lifting plate 202 with a clearance fit, and the clearance is 0.5 - 1.5 mm. Symmetric chutes are provided on the lifting plate 202, and polytetrafluoroethylene wear-resistant bushings are inlaid on the inner walls of the chutes.

[0031] The symmetrically distributed filter plates 102 are provided with symmetrically distributed sliding columns 1021 on the side close to the branch inlet 109. The surface of the sliding column 1021 is treated with hard chromium plating, and its diameter has a clearance fit with the width of the sliding groove. The sliding column 1021 is arranged in the sliding groove. An inner convex column is provided on the top wall of the lifting plate 202, and the convex column is in extrusion fit with the inclined surface of the convex block 201. When the grinding roller 105 rotates, the inclined surface of the convex block 201 periodically extrudes the convex column of the lifting plate 202, generating a reciprocating lifting motion. Through the linkage of the sliding groove and the sliding column 1021, the filter plate 102 is driven to vibrate, realizing the self-cleaning function of the impurity interception surface.

[0032] As Figure 6 shown, the output shaft on the lower side of the double-shaft motor 103 is connected with a connecting shaft 301 through a coupling. A rubber buffer pad is embedded in the coupling to absorb vibration shock. A number of second pressure-increasing pieces 302 are welded on the connecting shaft 301. The pressure-increasing pieces are in a spiral fan-shaped structure. The clearance between the outer edge of the second pressure-increasing piece 302 and the inner wall of the discharge cylinder 1011 is 1.5 - 2.5 mm, forming a centrifugal pressure-increasing cavity, and the pressure-increasing efficiency is increased by 15% - 20% compared with the conventional design.

[0033] During use, align the feed pipe with the upper opening of the housing 101, and use appropriate clamps or connectors to firmly fix the feed pipe to the end of the upper opening of the housing 101. After the liquid material enters the housing 101 through the feed pipe, the "V"-shaped inclined filter plate 102 intercepts undissolved phosphate particles and impurities. The intercepted coarse materials slide along the filter plate 102 to both sides of the branch inlet 109 under the action of gravity and enter the grinding cylinder 108 for secondary treatment.

[0034] The coarse materials entering the grinding cylinder 108 are crushed by the high-speed rotation of the grinding roller 105 to a particle size < 50 μm, and the fine materials are forced into the drain pipe 107 by the centrifugal force generated by the spiral first pressure-increasing piece 106 and flow back to the double-loop cavity.

[0035] When the double-shaft motor 103 drives the grinding roller 105 to rotate, the inclined surface of the convex block 201 at its end periodically extrudes the convex column of the lifting plate 202, forcing the lifting plate 202 to drive the filter plate 102 to vibrate up and down. Through the linkage of the sliding column 1021 and the sliding groove, the filter holes are self-cleaned, avoiding blockage and improving the filtration efficiency.

[0036] The lower output shaft of the double-shaft motor 103 drives the second pressure-increasing piece 302 to rotate, forming a centrifugal pressure-increasing cavity with a clearance of 1.5 - 2.5 mm from the inner wall of the discharge cylinder 1011, increasing the pressure of the liquid material by 0.8 - 1.2 MPa, ensuring that the atomization particle size ≤ 50 μm, and at the same time reducing the discharge resistance.

[0037] After the high-pressure liquid material enters the fixed nozzle 104, it forms a high-speed jet, instantaneously contacts with the heat medium at 200 - 300 °C, realizes efficient heat and mass transfer, and obtains anhydrous calcium hydrogen phosphate powder with uniform particle size.

[0038] Example 2: On the basis of Example 1, as Figure 7 and Figure 8 shown, a rotary nozzle 402 is rotatably connected to the outside of the discharge cylinder 1011. A plurality of second liquid discharge ports 4021 are circumferentially formed on its inner wall. The second liquid discharge ports 4021 are circumferentially equidistantly distributed. A plurality of first liquid discharge ports 401 are circumferentially formed on the inner wall of the discharge cylinder 1011. The first liquid discharge ports 401 and the second liquid discharge ports 4021 are staggeredly distributed. The rotary nozzle 402 and the discharge cylinder 1011 are connected by a flange, and the flange sealing surface uses a fluororubber O-ring to achieve dynamic sealing.

[0039] A pressure relief cylinder 406 is fixedly connected to the discharge cylinder 1011. A driving rod 404 is slidably connected to the pressure relief cylinder 406, and is in clearance fit with the inner wall of the pressure relief cylinder 406. A second spring 405 is connected between the driving rod 404 and the pressure relief cylinder 406. The second spring 405 is wound around the driving rod 404. A bent guide groove 403 is formed inside the rotary nozzle 402. A polytetrafluoroethylene wear-resistant bushing is embedded in the guide groove 403. The driving rod 404 slides in the guide groove 403 through a ball bearing provided at the end.

[0040] As Figure 9 shown, an annular light belt 501 is installed outside the fixed nozzle 104. The light belt adopts an IP67 waterproof grade, and the light source is a high-brightness LED, which is connected to the nozzle through a flange buckle.

[0041] When the pressure in the discharge cylinder 1011 exceeds the threshold value, the pressure acts on the driving rod 404, causing it to move downward, and the second spring 405 deforms. Since the end of the driving rod 404 is stuck in the bent guide groove 403 of the rotary nozzle 402, its downward movement drives the rotary nozzle 402 to rotate through the spiral trajectory of the guide groove 403, so that the second liquid discharge port 4021 is aligned with the first liquid discharge port 401. The high-pressure liquid material enters the 402 through the aligned liquid discharge ports and then is sprayed out through the 402 to form a uniform atomization effect. The rotation angle of the rotary nozzle 402 is regulated in real time by the system pressure to ensure that the spraying flow rate of the first liquid discharge port 401 is synchronously matched with that of the fixed nozzle 104, and to avoid uneven atomization particle size or nozzle blockage caused by sudden pressure increase.

[0042] When the pressure in the discharge cylinder 1011 is lower than the threshold value, under the elastic force of the second spring 405, the driving rod 404 moves upward and resets, thereby driving the rotary nozzle 402 to also rotate and reset in the reverse direction; the annular light belt 501 is turned on during the operation of the device to provide lighting for the staff and visual monitoring of the atomization state. Through the light scattering effect, the atomization uniformity of the rotary nozzle 402 and the fixed nozzle 104 can be directly observed, which is convenient for quickly judging the operation efficiency of the system.

[0043] Although the present invention has been described in detail with reference to the above embodiments, it will be apparent to those skilled in the art from this disclosure that various changes or modifications can be made to the present invention without departing from the principles and spirit of the invention as defined by the claims. Therefore, the detailed description of the embodiments of this disclosure is only for explanation and not for limiting the present invention, but the scope of protection is defined by the content of the claims.

Claims

1. A pressurized spray drying system for producing anhydrous calcium hydrogen phosphate, comprising a housing (101) with upper and lower openings. A discharge cylinder (1011) is fixedly installed at the lower opening, and a spray head (104) is fixedly installed at the end of the discharge cylinder (1011). It is characterized in that: Near the upper opening of the housing (101), symmetrically distributed filter plates (102) are rotatably connected. The two filter plates (102) are inclined inward. On both sides of the housing (101), branch ports (109) are provided corresponding to the inclined ends of the filter plates (102). On one side of the housing (101) near the branch ports (109), a grinding cylinder (108) is fixedly connected. A double-shaft motor (103) is installed on the outer side of the housing (101). The upper output shaft thereof penetrates through the grinding cylinder (108) and is connected to a grinding roller (105) through a coupling. Drain pipes (107) are symmetrically connected to both sides of the grinding cylinder (108). The outlets of the symmetrically distributed drain pipes (107) are all located in the rectangular cavity.

2. The pressurized spray drying system for producing anhydrous calcium hydrogen phosphate according to claim 1, characterized in that: A number of first booster plates (106) are also connected to the upper output shaft of the double-shaft motor (103).

3. The pressurized spray drying system for producing anhydrous calcium hydrogen phosphate according to claim 2, wherein: A convex block (201) is fixedly connected to the end of the grinding roller (105), and it has an inclined surface. On one side of the housing (101) near the convex block (201), symmetrically distributed first springs (203) are fixedly connected. A lifting plate (202) is connected between the symmetrically distributed first springs (203). The grinding roller (105) passes through the lifting plate (202) with a clearance fit. Symmetric chutes are provided on the lifting plate (202). On the side of the symmetrically distributed filter plates (102) near the branch ports (109), symmetrically distributed sliding columns (1021) are provided, and the sliding columns (1021) are arranged in the chutes.

4. The pressurized spray drying system for producing anhydrous calcium hydrogen phosphate according to claim 3, wherein: On the inner side of the top wall of the lifting plate (202), a convex column is provided, and the convex column is in pressing fit with the inclined surface of the convex block (201).

5. A pressure spray drying system for producing anhydrous calcium hydrogen phosphate as described in claim 4, characterized in that: The lower output shaft of the double-shaft motor (103) is connected to a connecting shaft (301) through a coupling. A number of second booster plates (302) are welded on the connecting shaft (301).

6. A pressure spray drying system for producing anhydrous calcium hydrogen phosphate as described in claim 5, characterized in that: A rotating spray head (402) is rotatably connected to the outer side of the discharge cylinder (1011). A number of second drain ports (4021) are circumferentially provided on its inner wall, and the second drain ports (4021) are circumferentially equidistributed. A number of first drain ports (401) are circumferentially provided on the inner wall of the discharge cylinder (1011), and the first drain ports (401) are staggered with the second drain ports (4021).

7. A pressure spray drying system for producing anhydrous calcium hydrogen phosphate as claimed in claim 6, characterized in that: A pressure relief cylinder (406) is fixedly connected to the discharge cylinder (1011). A driving rod (404) is slidably connected in the pressure relief cylinder (406). A second spring (405) is connected between the driving rod (404) and the pressure relief cylinder (406), and the second spring (405) is wound around the driving rod (404). A bent guide groove (403) is provided inside the rotating spray head (402), and the driving rod (404) slides in the guide groove (403) through a ball bearing provided at the end.

8. The pressure spray drying system for producing anhydrous calcium hydrogen phosphate according to claim 7, characterized in that: An annular light strip (501) is installed on the outer side of the fixed spray head (104).

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