Precipitated silica fine powder wet granulation system

Abstract

The system is characterized by comprising a pulper, a slurry storage tank, a drying tower and a fine powder dust collector connected in sequence, a fine powder bin connected to the pulper, and a fine powder outlet of the fine powder dust collector connected to a feeding port of the fine powder bin.

Description

Technical Field

[0001] This utility model relates to the field of granulation system technology, specifically to a wet granulation system for precipitated silica fine powder. Background Technology

[0002] Existing methods for granulating silica employ traditional drying techniques, such as centrifugal atomizers and pressure spray dryers.

[0003] The product obtained by centrifugal atomization is a powder, which causes dust pollution during use. Powdered silica is usually briquetized to obtain briquette silica products, but the powder content of the product is high, the particle size distribution of the briquette is uneven, the strength of the briquette particles is low, and the particles are easily broken.

[0004] Microsphere silica products obtained by pressure spray dryer have uniform particle size, but because they are obtained by direct drying of slurry with a solid content of 20%-25%, the slurry has a high water content, the drying temperature is as high as 400-600℃, the energy consumption is high, and the drying cost is high.

[0005] Micropearl precipitated silica has an average particle size of 200-250 micrometers. It is produced by spray drying a liquid slurry with a solid content of about 20% and removing fine powder. During the production process, more than 15% of the fine powder with a particle size of less than 150 micrometers is generated. Because the particle size does not meet the requirements for microspheres, it must be downgraded and sold, reducing the expected profit.

[0006] The prior art discloses a patent with publication number CN114632469A. This solution addresses the problems of high dust pollution in powdered silica products, high powder content in briquette silica products, and high drying costs for microbead silica. The method described involves solid-liquid separation, washing, pulping, grinding, and further solid-liquid separation followed by granulation, drying, and sieving to obtain silica briquettes with uniform particle size distribution. This method is simple, easy to operate, and produces granulated silica products with high purity and low production costs. It can be used to prepare rubber products, coatings, inks, adhesives, silicone rubber products, etc.

[0007] The shortcomings of existing technology have gradually become apparent with use, mainly in the following aspects:

[0008] First, all the fine powders are mixed back into the liquid slurry before spray drying and mixed into a uniform slurry. However, due to the structural limitations of the mixing, it is impossible to guarantee the uniformity of the mixing.

[0009] Secondly, in existing wet granulation systems, the slurry storage tank is prone to slurry adhering to the walls during storage, making it impossible to quickly discharge the slurry and affecting the use of subsequent equipment.

[0010] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Utility Model Content

[0011] To address the shortcomings of existing technologies, this invention provides a wet granulation system for precipitated silica fine powder. This system solves the problems of traditional technologies where all fine powders are incorporated back into the liquid slurry before spray drying and mixed into a uniform slurry. However, due to structural limitations in the mixing process, the uniformity of the mixture cannot be guaranteed. Furthermore, existing wet granulation systems often suffer from slurry adhesion to the walls of the slurry storage tank during storage, hindering rapid slurry discharge and affecting the use of subsequent equipment.

[0012] To achieve the above objectives, this utility model provides the following technical solution:

[0013] A wet granulation system for precipitated silica fine powder includes a pulping machine, a slurry storage tank, a drying tower, and a fine powder dust collector connected in sequence. The pulping machine is connected to a fine powder silo, and the fine powder outlet of the fine powder dust collector is also connected to the inlet of the fine powder silo.

[0014] As an optimized solution, an automatic weighing and feeding machine is connected between the fine powder silo and the pulping machine.

[0015] As an optimized solution, the feed end of the pulper is also connected to a filter press.

[0016] As an optimized solution, the outlet end of the filter press is connected to a hopper, and the outlet end of the hopper is connected to the feed end of the pulper.

[0017] As an optimized solution, a slurry transfer pump is connected between the pulper and the slurry storage tank.

[0018] As an optimized solution, a pressure pump is provided between the slurry storage tank and the drying tower.

[0019] As an optimized solution, the lower end of the drying tower is connected to a granular material hopper.

[0020] As an optimized solution, the air outlet end of the fine dust collector is connected to an induced draft fan.

[0021] As an optimized solution, the slurry storage tank is equipped with a scraping assembly that rubs against its inner wall.

[0022] As an optimized solution, the scraping assembly includes a central shaft rotatably mounted inside the slurry storage tank. The lower end of the central shaft is surrounded by a plurality of bottom scraping plates that rub against the bottom surface of the slurry storage tank. The outlet end of the slurry storage tank is located on the side wall near the bottom of the slurry storage tank.

[0023] As an optimized solution, the bottom scraper is arc-shaped and rotates along its outward convex direction.

[0024] As an optimized solution, each of the bottom scrapers has a side scraper that is vertically fixed to its outer end and makes frictional contact with the inner wall of the slurry storage tank.

[0025] As an optimized solution, the upper end of each of the side scrapers is fixed to the central shaft by a reinforcing rod.

[0026] Compared with the prior art, the beneficial effects of this utility model are:

[0027] All fine powders are incorporated back into the liquid slurry before spray drying and mixed into a uniform slurry. The step of incorporating the fine powders into the filter cake slurry machine has sufficient stirring intensity and stirring time to ensure uniform mixing.

[0028] The slurry containing fine powder is spray-dried, and more than 80% of the fine powder becomes granules, realizing wet granulation; about 15% of the fine powder that does not become granules and the newly generated fine powder are all recycled back into the liquid slurry, continuously circulating, completely eliminating the variety of fine powder, leaving only the variety of granules. The continuous recycling of fine powder is equivalent to fully realizing wet granulation.

[0029] Equipped with an automatic fine powder weighing and feeding system, it ensures the stability of the solid content and viscosity of the liquid slurry, precisely controls the amount of fine powder to be added back, and ensures that there is no residue of fine powder and that it is mixed evenly. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0031] Figure 1 This is a schematic diagram of the structure of this utility model;

[0032] Figure 2 This is a schematic diagram of the scraping assembly of this utility model.

[0033] In the diagram: 1-Pulping machine; 2-Pulp storage tank; 3-Drying tower; 4-Fine powder dust collector; 5-Filter press; 6-Hopper; 7-Fine powder silo; 8-Automatic weighing feeder; 9-Pulp transfer pump; 10-Pressure pump; 11-Particle material silo; 12-Fine powder outlet; 13-Exhaust fan; 14-Central shaft; 15-Bottom scraper; 16-Top scraper. Detailed Implementation

[0034] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0035] like Figure 1 and Figure 2 As shown, the wet granulation system for precipitated silica fine powder includes a pulper 1, a slurry storage tank 2, a drying tower 3, and a fine powder dust collector 4 connected in sequence. The pulper 1 is connected to a fine powder silo 7, and the fine powder outlet 12 of the fine powder dust collector 4 is also connected to the inlet of the fine powder silo 7.

[0036] An automatic weighing and feeding machine 8 is connected between the fine powder silo 7 and the pulping machine 1.

[0037] The feed end of the pulper 1 is also connected to the filter press 5.

[0038] The outlet end of the filter press 5 is connected to the hopper 6, and the outlet end of the hopper 6 is connected to the feed end of the pulper 1.

[0039] A slurry transfer pump 9 is connected between the pulping machine 1 and the slurry storage tank 2.

[0040] A pressure pump 10 is installed between the slurry storage tank 2 and the drying tower 3.

[0041] The lower end of the drying tower 3 is connected to a granular material silo 11.

[0042] The air outlet of the fine dust collector 4 is connected to an induced draft fan 13.

[0043] The slurry storage tank 2 is equipped with a scraping component that rotates and rubs against its inner wall.

[0044] The scraping assembly includes a central shaft 14 rotatably installed inside the slurry storage tank 2. The lower end of the central shaft 14 is surrounded by several bottom scraping plates 15 that rub against the bottom surface of the slurry storage tank 2. The outlet end of the slurry storage tank 2 is located on the side wall near the bottom of the slurry storage tank 2.

[0045] The bottom scraper 15 is arc-shaped and rotates along its outward convex direction, which can throw the slurry into the outside of the slurry storage tank 2 and make it quickly discharged along the outlet end.

[0046] By setting the bottom scraper 15 and the side scraper 16, frictional contact is achieved with the inner wall of the slurry storage tank 2, which scrapes the material, prevents the slurry from sticking to the wall, and improves the speed of material discharge.

[0047] Each bottom scraper 15 has a side scraper that is vertically fixed to its outer end and rubs against the inner wall of the slurry storage tank 2.

[0048] The upper end of each side scraper is fixed to the central shaft 14 by a reinforcing rod.

[0049] The main structures, including the pulper 1, automatic weighing and feeding machine 8, filter press 5, slurry storage tank 2, drying tower 3, and fine powder dust collector 4, are all known in the field. Since the specific structure is not an innovation of this solution, it will not be described in detail here. The innovation of this invention lies in the connection sequence between the main components and the rapid discharge of slurry from the discharge tank.

[0050] The working principle of this device is as follows:

[0051] All fine powders are incorporated back into the liquid slurry before spray drying and mixed into a uniform slurry. The step of incorporating the fine powders into the filter cake slurry machine 1 has sufficient stirring intensity and stirring time to ensure uniform mixing.

[0052] The slurry containing fine powder is spray-dried, and more than 80% of the fine powder becomes granules, realizing wet granulation; about 15% of the fine powder that does not become granules and the newly generated fine powder are all recycled back into the liquid slurry, continuously circulating, completely eliminating the variety of fine powder, leaving only the variety of granules. The continuous recycling of fine powder is equivalent to fully realizing wet granulation.

[0053] Equipped with an automatic fine powder weighing and feeding system, it ensures the stability of the solid content and viscosity of the liquid slurry, precisely controls the amount of fine powder to be added back, and ensures that there is no residue of fine powder and that it is mixed evenly.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A wet granulation system for precipitated silica fine powder, characterized in that: The system includes a pulper (1), a pulp storage tank (2), a drying tower (3), and a fine powder dust collector (4) connected in sequence. The pulper (1) is connected to a fine powder silo (7), and the fine powder outlet (12) of the fine powder dust collector (4) is also connected to the inlet of the fine powder silo (7). The slurry storage tank (2) is equipped with a scraping assembly that rotates and rubs against its inner wall. The scraping assembly includes a central shaft (14) rotatably mounted inside the slurry storage tank (2). The lower end of the central shaft (14) is surrounded by a plurality of bottom scraping plates (15) that rub against the bottom surface of the slurry storage tank (2). The outlet end of the slurry storage tank (2) is located on the side wall near the bottom of the slurry storage tank (2). The bottom scraper plate (15) is arc-shaped and rotates along its outward convex direction. Each of the bottom scrapers (15) has a side scraper that is vertically fixed to its outer end and is in frictional contact with the inner wall of the slurry storage tank (2).

2. The wet granulation system for precipitated silica fine powder according to claim 1, characterized in that: An automatic weighing and feeding machine (8) is connected between the fine powder silo (7) and the pulping machine (1).

3. The wet granulation system for precipitated silica fine powder according to claim 1, characterized in that: The feed end of the pulper (1) is also connected to a filter press (5), and the outlet end of the filter press (5) is connected to a hopper (6), and the outlet end of the hopper (6) is connected to the feed end of the pulper (1).

4. The wet granulation system for precipitated silica fine powder according to claim 1, characterized in that: A slurry transfer pump (9) is connected between the pulping machine (1) and the slurry storage tank (2), and a pressure pump (10) is provided between the slurry storage tank (2) and the drying tower (3).

5. The wet granulation system for precipitated silica fine powder according to claim 1, characterized in that: The lower end of the drying tower (3) is connected to a granular material silo (11).

6. The wet granulation system for precipitated silica fine powder according to claim 1, characterized in that: The air outlet end of the fine dust collector (4) is connected to an induced draft fan (13).

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