Crystallization separator with salt leg

Abstract

The invention relates to the technical field of crystal separators, in particular to a crystal separator with a salt leg, which comprises a crystal separation cylinder, a salt leg cylinder arranged below the crystal separation cylinder, a stirring mechanism, an outer cylinder body and an inner cylinder body, the outer barrel body is provided with an upper end connecting section and a lower end growing section which are connected in sequence, and the upper end connecting section of the outer barrel body is fixed on the inner circumferential wall of the salt leg barrel. When the salt leg barrel is used, the upper end of the inner barrel body is lower than the upper end of the outer barrel body, and the lower end of the inner barrel body is higher than the lower end of the outer barrel body; a crystal growth area with a downward opening is formed between the lower end growth section of the outer barrel and the salt leg barrel, and a clarification area is formed between the inner barrel and the lower end growth section of the outer barrel, so that the structure can be used for carrying out size grading on salt particles in the salt leg barrel, the particle size of the finally obtained product is increased, and the particles are uniformly distributed; the salt particles can be collected more easily, and fine grains of fine salt can be eliminated in a concentrated manner.

Description

Technical Field

[0001] The present invention relates to the technical field of crystallization separators, in particular to a crystallization separator with salt legs. Background Art

[0002] Currently, in the field of wastewater treatment, wastewater containing large amounts of inorganic salts such as sodium chloride, ammonium chloride, sodium sulfate, and ammonium sulfate is often produced in many production fields such as chemical, fertilizer, pesticide, and textile industries. If high-salt wastewater is discharged directly without treatment, it will not only pollute the environment but also cause soil salinization in serious cases. Therefore, a suitable, feasible, and cost-effective method for wastewater treatment is needed. At present, the main wastewater treatment methods include physical and chemical filtration, MVR evaporation concentration, multi-effect evaporation technology, and membrane purification technology. MVR evaporation, single-effect evaporation, and multi-effect evaporation systems have been widely used in wastewater treatment processes.

[0003] The salt legs of the crystallizers in MVR evaporation, single-effect evaporation, and multi-effect evaporation systems generally do not have the function of particle size distribution, nor do they have the process of eliminating and dissolving fine salt particles. During system operation, large and small salt particles are discharged together into the centrifuge for filtration, resulting in generally small salt particles and uneven particle size distribution, which seriously affects the sales value of the product salt.

[0004] Therefore, it is very important to develop a new type of crystallization separator. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: in order to solve the problem that the salt legs of the crystallizer generally have no function of particle size distribution and no process of eliminating and dissolving fine salt particles, large-particle salt and small-particle salt are discharged together to the centrifuge for filtration during system operation, resulting in the salt particles generated by the system being generally small and the particle size distribution being uneven, which seriously affects the sales value of the product salt. A crystallizer with salt legs is now provided.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a crystallization separator with salt legs, including a crystallization separation cylinder and a salt leg cylinder arranged below the crystallization separation cylinder, the bottom of the salt leg cylinder is provided with a head, and also includes an outer cylinder and an upper inner cylinder, the outer cylinder has an upper end connecting section and a lower end growth section connected in sequence, the upper end connecting section of the outer cylinder is fixed on the inner circumferential wall of the salt leg cylinder, the outer cylinder and the salt leg cylinder are spaced apart from each other and form a crystal growth area with an opening facing downward, the upper inner cylinder and the lower inner cylinder are fixed in the outer cylinder along the axial direction of the outer cylinder, the upper end of the upper inner cylinder is located below the upper end of the outer cylinder, and the lower The lower end of the inner cylinder is located above the lower end of the outer cylinder, and the outer cylinder and the upper inner cylinder and the lower inner cylinder are spaced apart from each other. The upper inner cylinder and the lower inner cylinder are both located in the lower end growth section of the outer cylinder, and a clarification area is formed between the upper end of the upper inner cylinder and the lower end growth section of the outer cylinder. A stirring mechanism is provided in the upper inner cylinder and the lower inner cylinder, and a conveying pipe is provided under the upper inner cylinder. The conveying pipe is used to convey refined brine into the upper inner cylinder, and the head is respectively provided with a first discharge port connected to the interior, the crystallization separation cylinder is provided with a second feed port, and the salt leg cylinder is provided with a fine crystal outlet connected to the crystal growth area. Compared with the existing technology, this solution makes the upper end of the upper inner cylinder lower than the upper end of the outer cylinder, the lower end of the lower inner cylinder higher than the lower end of the outer cylinder, and forms a crystal growth zone with an opening facing downward between the outer cylinder and the salt leg cylinder, as well as a clarification zone between the upper inner cylinder and the lower end growth section of the outer cylinder, and combines the conveying pipe to transport the refined brine, and performs particle size classification on the salt particles in the salt leg cylinder, so that the final product particle size becomes larger and the particle distribution is uniform, which is more conducive to the collection of salt particles and the fine salt can be concentrated for fine crystal elimination. After the salt leg is modified, the circulation flow required for fine crystal elimination is smaller (because the salt is more concentrated), and the system operation energy consumption is low. At the same time, the lower inner cylinder cooperates with the stirring mechanism to achieve smoothing of the generated salt to prevent agglomeration, which is convenient for later use.

[0007] Since the crystals inside the crystallization separation cylinder will adhere to the inner wall during growth, as the production time increases, the crystals attached to the inner wall will grow, and after growing to a certain extent, they will detach on their own. The crystals that fall off after agglomeration will fall to the stirring mechanism below, causing the stirring mechanism to get stuck and unable to stir. It is necessary to stop production and carry out repairs, which reduces production efficiency and increases production and maintenance costs. Preferably, some embodiments are provided with a fixed screen between the crystallization separation cylinder and the salt leg cylinder. By fixing the screen between the crystallization separation cylinder and the salt leg cylinder, the screen can intercept and block the falling crystals, preventing the falling crystals from getting stuck in the stirring mechanism.

[0008] In order to ensure that the blocking net is effective and reliable, some embodiments are preferred. In some embodiments, the blocking net has an inner net part and an outer net part connected in sequence from the inside to the outside, the inner net part is located above the upper inner cylinder and covers the upper inner cylinder, and the mesh aperture of the outer net part is larger than the mesh aperture of the inner net part.

[0009] In order to realize the stirring mechanism, some embodiments are preferred, wherein the stirring mechanism includes a rotating shaft rotatably mounted on the head, a plurality of stirring paddles are provided at one end of the rotating shaft, a part of the plurality of stirring paddles are located in the upper inner cylinder, another part of the plurality of stirring paddles are located in the lower inner cylinder, and a driving mechanism is provided at the other end of the rotating shaft.

[0010] In some preferred embodiments, the driving mechanism is a servo motor.

[0011] In some preferred embodiments, the cross-section of the upper end connecting section of the outer cylinder is an inclined surface, and the inclined surface is gradually inclined downward from the outside of the salt leg cylinder to the inside.

[0012] Preferably, in some embodiments, the head is conical.

[0013] In some preferred embodiments, the ratio of the diameter of the outer cylinder to the diameters of the upper inner cylinder and the lower inner cylinder is 2-1.2.

[0014] The beneficial effects of the present invention are as follows: when the crystallizer with salt legs is in use, the upper end of the upper inner cylinder is lower than the upper end of the outer cylinder, the lower end of the lower inner cylinder is higher than the lower end of the outer cylinder, and a crystal growth zone with an opening facing downward is formed between the outer cylinder and the salt leg cylinder, and a clarification zone is formed between the upper inner cylinder and the lower end growth section of the outer cylinder, and the refined brine is transported in combination with the conveying pipe to perform particle size classification on the salt particles in the salt leg cylinder, so that the particle size of the final product becomes larger and the particle distribution is uniform, which is more conducive to the collection of salt particles and concentrates on the fine salt particles that can be transported. Fine crystal elimination is carried out. After the salt legs are modified, the circulation flow required for fine crystal elimination is smaller (because the salt is more concentrated), and the system has low energy consumption. At the same time, the lower inner cylinder and the stirring mechanism cooperate to grind the generated salt flat to prevent agglomeration, which is convenient for later use. It avoids the problem that the salt legs of the crystallizer generally have no particle size distribution function and no process of eliminating and dissolving fine salt particles. During the operation of the system, large and small salt particles are discharged together to the centrifuge for filtration, resulting in the salt particles generated by the system being generally small and the particle size distribution being uneven, which seriously affects the sales value of the product salt. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below with reference to the accompanying drawings and examples.

[0016] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 yes Figure 1 A partial enlarged view of middle A; Figure 3 A schematic diagram of the structure of the salt leg tube and the barrier net in the present invention; Figure 4 It is a top view of the blocking net in the present invention.

[0017] In the figure: 1. Crystallization separation cylinder, 2. Salt leg cylinder, 3. Head, 4. Stirring mechanism, 5. Outer cylinder, 6. Upper inner cylinder, 7. Upper connecting section, 8. Lower growth section, 9. Crystal growth zone, 10. Clarification zone, 11. First discharge port, 13. Second feed port, 14. Fine crystal outlet, 15. Screen, 16. Inner mesh part, 17. Outer mesh part, 18. Rotating shaft, 19. Stirring paddle, 20. Driving mechanism, 21. Lower inner cylinder, 22. Delivery pipe. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below in conjunction with the embodiments: The present invention is not limited to the following specific embodiments. Based on the disclosure of the present invention, a person skilled in the art may adopt a variety of other specific embodiments to implement the present invention. Any simple changes or modifications made to the design structure and concept of the present invention fall within the scope of protection of the present invention. It should be noted that the embodiments and features of the embodiments of the present invention may be combined with each other unless they conflict.

[0019] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0020] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0021] like Figure 1-4 As shown, a crystallization separator with salt legs comprises a crystallization separation cylinder 1, a salt leg cylinder 2, an outer cylinder 5, an upper inner cylinder 6 and a lower inner cylinder 21. The salt leg cylinder 2 is arranged below the crystallization separation cylinder 1. The diameter of the crystallization separation cylinder 1 is larger than the diameter of the salt leg cylinder 2. A head 3 is provided at the bottom of the salt leg cylinder 2. The outer cylinder 5 has an upper connecting section 7 and a lower growth section 8 connected in sequence. The upper connecting section 7 of the outer cylinder 5 is fixed on the inner circumferential wall of the salt leg cylinder 2. The outer cylinder 5 and the salt leg cylinder 2 are spaced apart from each other and form a crystal growth zone 9 with an opening facing downward. The upper inner cylinder 6 and the lower inner cylinder 21 are both fixed in the outer cylinder 5. The upper inner cylinder 6 and the lower inner cylinder 21 are spaced apart along the axial direction of the outer cylinder 5, and the outer cylinder 5, the upper inner cylinder 6 and the lower inner cylinder 21 are coaxially arranged. The upper end of the upper inner cylinder 6 is located below the upper end of the outer cylinder 5. The lower inner cylinder 2 1 The lower end is located above the lower end of the outer cylinder 5, and the outer cylinder 5 is spaced from the upper inner cylinder 6 and the lower inner cylinder 21. The upper inner cylinder 6 and the lower inner cylinder 21 are both located in the lower end growth section 8 of the outer cylinder 5. A clarification zone 10 is formed between the upper end of the upper inner cylinder 6 and the lower end growth section 8 of the outer cylinder 5. A stirring mechanism 4 is provided in each of the upper inner cylinder 6 and the lower inner cylinder 21. A conveying pipe 22 is provided below the upper inner cylinder 6. The conveying pipe 22 is used to convey refined brine into the upper inner cylinder 6. The head 3 is respectively provided with a first discharge port 11 connected to the interior, and the first discharge port 11 is used to discharge large-particle crystals. The crystallization separation cylinder 1 is provided with a second feed port 13, and the second feed port 13 is used to feed fine crystal dissolution. The salt leg cylinder 2 is provided with a fine crystal outlet 14 connected to the crystal growth zone 9. The head 3 is conical.

[0022] That is, the outer cylinder 5 separates the different functional areas in the salt leg cylinder 2. Among them, the crystals in the clarification area 10 settle in the mother liquor and are discharged from the first discharge port 11 of the head 3. The fine crystals are discharged from the top fine crystal outlet 14 and then returned to the salt leg of the crystallization separator after being dissolved by fresh feeding or heating with steam / hot water / cooling with cold water.

[0023] A blocking net 15 is fixedly installed between the crystallization separation cylinder 1 and the salt leg cylinder 2. The blocking net 15 is located above the outer cylinder 5. The blocking net 15 has an inner net part 16 and an outer net part 17 connected in sequence from the inside to the outside. The inner net part 16 is located above the upper inner cylinder 6 and covers the upper inner cylinder 6. The mesh aperture of the outer net part 17 is larger than the mesh aperture of the inner net part 16.

[0024] The stirring mechanism 4 includes a rotating shaft 18 rotatably mounted on the head 3, one end of the rotating shaft 18 is located in the salt leg tube 2, and one end of the rotating shaft 18 is provided with two stirring paddles 19, one stirring paddle 19 is located in the upper inner cylinder 6, and the other stirring paddle 19 is located in the lower inner cylinder 21. The other end of the rotating shaft 18 is provided with a driving mechanism 20, and the driving mechanism 20 is a servo motor. The servo motor is located outside the crystallizer. The salt leg tube 2 can adjust the rotation direction of the stirring mechanism 4. When the stirring is reversed, the large-particle salt rushes upward to the fine crystal elimination point, and the large-particle salt is continuously dissolved, meeting the needs of some companies to produce small-particle salt. Since the device usually generates hexagonal salt, the salt will clump, which is very inconvenient to use later. Conventionally, an anti-caking agent is used to prevent agglomeration. In this solution, the stirring paddle 19 in the lower inner cylinder 21 smoothes the edges and corners of the salt block, that is, the generated salt is spherical salt.

[0025] The cross section of the upper end connecting section 7 of the outer cylinder 5 is an inclined surface, which is gradually inclined downward from the outside of the salt leg tube 2 to the inside. The ratio of the diameter of the outer cylinder 5 to the diameter of the upper inner cylinder 6 and the lower inner cylinder 21 is 2 to 1.2. The diameter of the outer cylinder 5 is 0.6-0.9 of the diameter of the straight cylinder shell. For example, the diameter of the outer cylinder 5 exemplarily includes 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, etc. The upper inner cylinder 6 The diameter of the upper inner cylinder 6 and the lower inner cylinder 21 is 0.3-0.7 of the diameter of the straight cylindrical shell, and the diameters of the upper inner cylinder 6 and the lower inner cylinder 6 exemplarily include 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, etc. It should be noted here that the diameter of the upper inner cylinder 6 is equal to the diameter of the lower inner cylinder 21, and the diameters of the upper inner cylinder 6 and the lower inner cylinder 21 are both smaller than the diameter of the outer cylinder 5; The present invention does not specifically limit the diameters of the crystallization separation drum 1, the upper inner drum 6, the lower inner drum 21, and the outer drum 5. These diameters may be adjusted by those skilled in the art based on actual needs. When the diameters of the upper inner drum 6, the lower inner drum 21, and the outer drum 5 are within the ranges defined in this application, effective partitioning can be achieved, thereby enabling effective particle size classification of the salt particles in the salt drum 2.

[0026] When the above-mentioned crystallizer with salt legs is in use, the salt particles in the salt leg barrel 2 are acted upon by the stirring paddle 19 and the upper inner cylinder 6, and cooperate with the conveying pipe 22 to convey the refined brine into the upper inner cylinder 6, and the refined brine is used to eliminate fine crystals. The salt is subjected to a particle size classification in the salt leg barrel 2, and crystals with relatively small particles are distributed on the upper edge of the outer cylinder 5. The fine crystals are collected at this position, and the salt body is smoothed by the stirring paddle 19 in the lower inner cylinder 21, that is, the generated salt is smoothed into spherical salt. It should be noted that if the collected fine crystals enter the dissolution kettle and dissolve with the unsaturated raw material, the dissolved solution, due to the risk of dissolving the coarse crystals in the salt leg barrel 2, is pumped into the second feed port 13 on the upper side of the crystallization separation cylinder 1. If the collected fine crystals are dissolved by heating / cooling in the dissolution kettle, the dissolved solution is pumped into the bottom of the salt leg barrel 2 by the pump, and the crystals with larger particles are suspended at the bottom of the salt leg barrel 2 and continuously pumped into the centrifuge for centrifugal separation, so that the particle size of the product obtained is finally increased and the particle size distribution becomes uniform.

[0027] Application example: The above device is used to evaporate sodium chloride brine in a salt plant to make salt, including adding brine and controlling the temperature to 128~130℃ in the evaporation tank, and the temperature of the dissolving kettle to 134℃. When the stirring rate is 680~720r / min, the crystals can be stirred and the particle size classification can be achieved. The fine crystal elimination circulation volume is 5~10 m 3 / h, evaporation rate is 180-190m 3 / h, and when crystals are evaporated, continue evaporating for 6-8 h. There is no obvious explosive nucleation of crystals in the system, and the fine particles are also small. The main particle size can be controlled at about 1.0~1.2 mm.

[0028] The above description of the preferred embodiments of the present invention is intended to serve as a guide. Based on the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A crystallization separator with a salt leg, comprising a crystallization separation cylinder (1) and a salt leg cylinder (2) arranged below the crystallization separation cylinder (1), wherein a head (3) is arranged at the bottom of the salt leg cylinder (2), characterized in that: The invention also includes an outer cylinder (5), an upper inner cylinder (6) and a lower inner cylinder (21), wherein the outer cylinder (5) has an upper connecting section (7) and a lower growth section (8) connected in sequence, the upper connecting section (7) of the outer cylinder (5) is fixed on the inner peripheral wall of the salt leg cylinder (2), the outer cylinder (5) and the salt leg cylinder (2) are spaced apart from each other and form a crystal growth zone (9) with an opening facing downward, the upper inner cylinder (6) and the lower inner cylinder (21) are fixed in the outer cylinder (5) along the axial direction of the outer cylinder (5), the upper end of the upper inner cylinder (6) is located below the upper end of the outer cylinder (5), the lower end of the lower inner cylinder (21) is located above the lower end of the outer cylinder (5), and the outer cylinder (5) is provided with a plurality of intermediate portions between the upper inner cylinder (6) and the lower inner cylinder (21). They are spaced apart from each other, the upper inner cylinder (6) and the lower inner cylinder (21) are both located at the lower end growth section (8) of the outer cylinder (5), a clarification zone (10) is formed between the upper end of the upper inner cylinder (6) and the lower end growth section (8) of the outer cylinder (5), a stirring mechanism (4) is provided in each of the upper inner cylinder (6) and the lower inner cylinder (21), a conveying pipe (22) is provided below the upper inner cylinder (6), and the conveying pipe (22) is used to convey refined brine into the upper inner cylinder (6), a first discharge port (11) communicating with the interior is provided on the head (3), a second feed port (13) is provided on the crystallization separation cylinder (1), and a fine crystal outlet (14) communicating with the crystal growth zone (9) is provided on the salt leg cylinder (2).

2. A crystallization separator with salt legs according to claim 1, characterized in that: A blocking net (15) is fixedly provided between the crystallization separation cylinder (1) and the salt leg cylinder (2).

3. A crystallization separator with salt legs according to claim 2, characterized in that: The barrier net (15) comprises an inner net portion (16) and an outer net portion (17) connected in sequence from the inside out, the inner net portion (16) is located above the upper inner cylinder (6) and covers the upper inner cylinder (6), and the mesh aperture of the outer net portion (17) is larger than the mesh aperture of the inner net portion (16).

4. A crystallization separator with salt legs according to claim 1, characterized in that: The stirring mechanism (4) includes a rotating shaft (18) rotatably mounted on the head (3), a plurality of stirring paddles (19) are provided at one end of the rotating shaft (18), a portion of the plurality of stirring paddles (19) are located in the upper inner cylinder (6), and another portion of the plurality of stirring paddles (19) are located in the lower inner cylinder (21), and a driving mechanism (20) is provided at the other end of the rotating shaft (18).

5. The crystallization separator with salt legs according to claim 9, characterized in that: The driving mechanism (20) is a servo motor.

6. The crystallization separator with salt legs according to claim 1, characterized in that: The cross section of the upper end connecting section (7) of the outer cylinder (5) is an inclined surface, and the inclined surface is gradually inclined downward from the outside to the inside of the salt leg cylinder (2).

7. The crystallization separator with salt legs according to claim 1, characterized in that: The head (3) is conical.

8. The crystallization separator with salt legs according to claim 1, characterized in that: The ratio of the diameter of the outer cylinder (5) to the diameters of the upper inner cylinder (6) and the lower inner cylinder (21) is 2 to 1.2.

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