Two-stage thickening kettle

Abstract

The utility model discloses a two-stage thickening kettle which comprises a salt collecting hopper with a salt discharge port at the bottom, the top of the salt collecting hopper is connected with a barrel, an overflow flow guide weir is arranged at the top of the barrel, an overflow liquid discharge port is formed in the side direction of the overflow flow guide weir, a top cover is arranged above the overflow flow guide weir, and the salt collecting hopper, the barrel and the top cover are all hermetically connected to form a closed cavity; the two-stage thickening kettle further comprises a cyclone separator connected with the closed cavity in a sealed mode, a feeding port and a clear liquid outlet of the cyclone separator are both located outside the barrel, a heavy liquid outlet of the cyclone separator is located in the middle of the barrel, and the clear liquid outlet is provided with a valve. Through the coupling design of the cyclone separator and the closed cavity, the synergistic effect of first-stage hydraulic cyclone coarse separation and second-stage gravity settling fine separation is achieved. When the feed liquid treatment capacity is large and the feed concentration is low, the cyclone separator can pre-concentrate the low-concentration feed and discharge the clear liquid out of the system in advance, so that the subsequent treatment load is reduced.

Description

Technical Field

[0001] This utility model mainly relates to the field of concentration equipment technology, and in particular to thickening reactors. Background Technology

[0002] In the production processes of chemical, pharmaceutical, metallurgical, and new energy materials companies, high-salinity water is typically concentrated and separated using evaporation systems. The core processes of this system are as follows: feeding, preheating, heating and evaporation, thickening, centrifugation, and drying.

[0003] Taking the production of lithium carbonate, a key material in the new energy industry, as an example, it is generally prepared through an acid leaching process. During the concentration and salt separation of the raw lithium carbonate, the lithium precipitation mother liquor enters the evaporation system for secondary lithium carbonate recovery. The inorganic salt components in the mother liquor mainly include sodium sulfate and lithium carbonate, with sodium sulfate content of approximately 180 g / L and lithium carbonate in a saturated solution state with a concentration of 12.9 g / L. While the solubility of sodium sulfate is approximately 427 g / L, in this system, due to the influence of lithium carbonate salt and pH value, its actual saturated solubility is only about 350 g / L. To prevent sodium sulfate precipitation and its impact on the quality of the secondary lithium, the material is thickened when the evaporation concentration ratio reaches approximately 2 times. At this point, the crystals precipitated in the solution are lithium carbonate products, and based on the previous data, their solid content is extremely low, less than 1%.

[0004] However, the optimal solid-liquid ratio for centrifuge operation in the centrifugation process requires a solid-liquid ratio greater than 30%. Traditional thickeners typically have an optimal feed concentration of 10%-20%, which is clearly insufficient for such operating conditions. Therefore, there is an urgent need for a thickener capable of handling large liquid volumes and low feed concentrations. Utility Model Content

[0005] The technical problem this invention aims to solve is how to ensure a thickening effect under conditions of large liquid throughput and low feed concentration.

[0006] To overcome the shortcomings of existing technologies, a two-stage thickening reactor is provided.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] The two-stage thickening reactor includes a salt collection hopper with a salt discharge port at the bottom. The top of the salt collection hopper is connected to a cylindrical body. The top of the cylindrical body has an overflow guide weir, and an overflow discharge port is formed laterally on the overflow guide weir. A top cover is installed above the overflow guide weir. The salt collection hopper, the cylindrical body, and the top cover are all sealed together to form a closed cavity. The two-stage thickening reactor also includes a hydrocyclone separator sealed together with the closed cavity. The feed inlet and clear liquid outlet of the hydrocyclone separator are located outside the cylindrical body, while its heavy liquid outlet is located in the middle of the cylindrical body. The clear liquid outlet is equipped with a valve. Through the coupling design of the hydrocyclone separator and the closed cavity, the synergistic effect of primary hydrocyclone coarse separation and secondary gravity sedimentation fine separation is achieved. When the feed volume is large and the feed concentration is low, the hydrocyclone separator can pre-concentrate the low-concentration feed and discharge the clear liquid from the system in advance, thereby reducing the load on subsequent processing. The layout of the heavy liquid outlet located in the middle of the cylindrical body ensures that the pre-concentrated material has an optimal initial distribution state when entering the sedimentation zone. Furthermore, since the salt collection hopper, the cylinder, the top cover, and the hydrocyclone are all sealed together, the flow rate of the liquid flowing into the cylinder can be changed by adjusting the valve on the clear liquid outlet when the inlet volume remains constant. This allows the primary hydrocyclone coarse separation and the secondary gravity sedimentation fine separation to be linked, making the operation more convenient.

[0009] The lower part of the salt collection hopper is equipped with two flushing ports. One flushing port is connected to steam, and the other flushing port is connected to hot water. After the thickening process is completed, the inside of the sealed cavity can be back-flushed through the flushing ports to prevent the deposits from forming scale on the inner wall of the cavity, affecting the thickening effect and the normal operation of the equipment, and extending the service life of the equipment. This ensures that the equipment can always maintain a good working condition when processing materials for a long time, thereby improving the stability and reliability of the entire two-stage thickening reactor.

[0010] A packing layer is laid at the top opening of the cylinder. The packing layer uses anti-clogging random packing, which can effectively distribute the water evenly, ensure that the water passes through the overflow guide weir uniformly, avoid flow deviation, and prevent salt crystals from rising.

[0011] The upper half of the inner wall of the cylinder is provided with several flow-disrupting plates, which are evenly distributed along the circumference of the cylinder. The flow-disrupting plates are configured with a tripod support structure. By setting up the flow-disrupting plates, eddies can be effectively prevented, ensuring that the liquid passes stably through the packing layer. At the same time, by setting the flow-disrupting plates with a tripod support structure, salt spots can be effectively avoided at right-angle welds.

[0012] The bottom end of the cylinder tapers inward to form a conical shell-shaped cone head. This cone head design allows material to flow more concentratedly towards the center at the bottom of the cylinder, facilitating material discharge and collection. It also reduces material residue and accumulation at the bottom, preventing deterioration or clumping caused by prolonged material retention. This improves material processing efficiency and product quality. Furthermore, the shape of the cone head helps increase the overall strength and rigidity of the cylinder, enhancing the equipment's pressure resistance and ensuring safe and stable operation under high-pressure conditions.

[0013] The two-stage thickening reactor also includes a guide tube disposed in the upper half of the cylinder, and the heavy liquid outlet of the hydrocyclone separator is connected to the guide tube. The bottom of the guide tube has a funnel-shaped opening. The guide tube effectively guides the heavy liquid separated by the hydrocyclone separator to the central area of ​​the thickening reactor, ensuring thorough mixing between the heavy liquid and the material inside the cylinder, accelerating the thickening process. Simultaneously, the guide tube also acts as a guide, making the flow of material within the cylinder more orderly, reducing turbulence and eddies, further improving thickening efficiency and product quality, and ensuring rapid and effective concentration and separation of materials when processing large quantities of low-concentration feed. Furthermore, the top of the guide tube has a vent. The funnel shape expands the outflow area of ​​the heavy liquid, allowing it to enter the center of the cylinder more evenly, preventing salt crystals in the liquid from rising due to agitation.

[0014] The two-stage thickening reactor also includes a stirrer built into the cylinder, the top of which is connected to a drive device fixed to the top cover. The stirrer is configured as a frame structure, which fits against the inner wall of the cylinder.

[0015] The agitator thoroughly mixes the materials inside the cylinder, further enhancing the mixing process, accelerating crystal precipitation and aggregation, and improving thickening efficiency. The frame-type agitator fits snugly against the inner wall of the cylinder, effectively scraping away any material adhering to the inner wall and preventing scale buildup, thus ensuring the normal operation of the equipment. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a two-stage thickening reactor.

[0017] The labels in the diagram represent: 1. Salt collection hopper; 11. Salt discharge port; 12. Flushing port; 2. Cylinder body; 21. Packing layer; 22. Baffle plate; 23. Conical head; 3. Overflow guide weir; 31. Overflow discharge port; 4. Top cover; 5. Cyclone separator; 51. Feed inlet; 52. Clear liquid outlet; 53. Heavy liquid outlet; 6. Guide cylinder; 7. Agitator; 8. Drive unit. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Example

[0020] like Figure 1 As shown, in this embodiment, the two-stage thickening reactor includes a salt collecting hopper 1 with a salt discharge port 11 at the bottom. The top of the salt collecting hopper 1 is connected to the cylinder 2. The top of the cylinder 2 is provided with an overflow guide weir 3, and an overflow discharge port 31 is formed on the side of the overflow guide weir 3. A top cover 4 is installed above it. The salt collecting hopper 1, the cylinder 2, and the top cover 4 are all sealed together to form a closed cavity. The two-stage thickening reactor also includes a cyclone separator 5 eccentrically mounted through the top cover 4, which is sealed to the top cover 4. The feed port 51 and the clear liquid outlet 52 of the cyclone separator 5 are both located outside the cylinder 2, and its heavy liquid outlet 53 is located in the middle of the cylinder 2. The clear liquid outlet 52 is equipped with a valve. Specifically, the top of the overflow guide weir 3 is serrated, which makes the liquid surface more stable, and since there is no built-in support structure, it can reduce the salt deposition points.

[0021] In this embodiment, the salt collection hopper 1 adopts a narrow diameter structure, the diameter of which matches the salt production, which is conducive to the enrichment and growth of salt crystals. The lower part of the salt collection hopper 1 is provided with two rinsing ports 12, which are arranged vertically at intervals.

[0022] In this embodiment, a packing layer 21 is laid at the top opening of the cylinder 2, and anti-clogging loose packing is selected.

[0023] In this embodiment, the inner wall of the upper half of the cylinder 2 is provided with several turbulence-disrupting plates 22. The turbulence-disrupting plates 22 are evenly distributed along the circumference of the cylinder 2, and the turbulence-disrupting plates 22 are configured as a tripod support structure.

[0024] In this embodiment, the bottom end of the cylinder 2 is tapered inward to form a conical shell-shaped conical head 23.

[0025] In this embodiment, the two-stage thickening reactor also includes a guide tube 6 disposed in the upper half of the cylinder 2. The heavy liquid outlet 53 of the hydrocyclone separator 5 is connected to the guide tube 6, and a flared mouth is formed at the bottom of the guide tube 6.

[0026] In this embodiment, the two-stage thickening reactor also includes a stirrer 7 built into the cylinder 2. The top of the stirrer 7 is connected to a drive device 8 fixed on the top cover 4. The stirrer 7 is configured as a frame structure and fits against the inner wall of the cylinder 2.

[0027] When using a two-stage thickening reactor for thickening treatment, the low-solids-content liquid after evaporation enters through the feed inlet 51. Under the action of the hydrocyclone separator 5, it undergoes the first separation and concentration. The separated clear liquid flows out from the clear liquid outlet 52 and can be refluxed or sent to the next process as needed. The high-solids-content heavy liquid obtained from the hydrocyclone separation flows out from the heavy liquid outlet 53 at the bottom of the hydrocyclone separator 5 and enters through the guide tube 6. Under the guidance of the guide tube 6, the liquid reaches the middle of the cylinder 2 and continues to undergo the second separation. In the middle of the cylinder 2, the clear liquid rises through the packing layer 21 (the particles are intercepted by the packing layer), then overturns the top of the cylinder 2 and enters the overflow guide weir 3. After being guided by the overflow guide weir 3, it is discharged from the overflow discharge port 31 to the next stage. The solid crystals enter the middle of the cylinder 2 from the guide tube 6 and slowly sink under their own weight. After flowing through the cone head 23, they reach the salt collection hopper 1 at the bottom of the equipment. The solid crystals are enriched in the salt collection hopper 1 and then discharged to the rear centrifuge for dehydration through the salt discharge port 11.

[0028] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the present invention, or modify it into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, should fall within the protection scope of the present invention.

Claims

1. A double-stage thickening kettle, comprising a salt collecting bucket (1) provided with a salt discharging port (11) at the bottom, a cylinder (2) connected to the top of the salt collecting bucket (1), an overflow guide weir (3) provided at the top of the cylinder (2), a lateral overflow liquid discharging port (31) formed in the overflow guide weir (3), and a top cover (4) installed above the overflow guide weir (3), characterized in that: The salt collecting hopper (1), the barrel (2) and the top cover (4) are in sealing connection and form a closed cavity; the double-stage thickening kettle further comprises a cyclone separator (5) in sealing connection with the closed cavity, the feed inlet (51) and the clear liquid outlet (52) of the cyclone separator (5) are located outside the barrel (2), the heavy liquid outlet (53) is located at the middle part of the barrel (2), and the clear liquid outlet (52) is provided with a valve.

2. The two-stage pasty kettle according to claim 1, characterized in that: The lower part of the salt collecting hopper (1) is provided with two flushing openings (12).

3. The two-stage pasty kettle according to claim 1, characterized in that: The top opening of the barrel (2) is paved with a filler layer (21).

4. The two-stage pasty kettle according to claim 1, characterized in that: The inner wall of the upper half of the barrel (2) is provided with a plurality of spoiler plates (22), and the spoiler plates (22) are uniformly distributed along the circumference of the barrel (2).

5. The two-stage pasty kettle according to claim 4, characterized in that: The spoiler plates (22) are arranged in a tripod support structure.

6. The two-stage pasty kettle according to claim 1, characterized in that: The bottom end of the barrel (2) is inwardly folded to form a conical shell-shaped conical head (23).

7. The two-stage pasty kettle according to claim 1, characterized in that: The double-stage thickening kettle further comprises a flow guide cylinder (6) arranged in the upper half of the barrel (2), and the heavy liquid outlet (53) of the cyclone separator (5) is in communication with the flow guide cylinder (6).

8. The two-stage pasty kettle according to claim 7, characterized in that: The bottom of the flow guide cylinder (6) is formed with a bell mouth.

9. The two-stage pasty kettle according to claim 1, characterized in that: The double-stage thickening kettle further comprises a stirrer (7) arranged in the barrel (2), and the top end of the stirrer (7) is connected with a driving device (8) fixed on the top cover (4).

10. The two-stage pasty kettle according to claim 9, characterized in that: The stirrer (7) is arranged in a frame structure and is attached to the inner wall of the barrel (2).

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