A circulating accelerated crystallizer

Abstract

The utility model relates to a kind of circulating acceleration crystallizers, including first crystallization tank, second crystallization tank, second crystallization tank is installed in the lower end of first crystallization tank;First crystallization tank includes first shell, motor is installed in the top of first shell, feed hopper, the inside of first shell is penetrated with stirring shaft, the outside of stirring shaft is fixed with multiple pieces of stirring blade, stirring rod, the inside shaft direction of stirring shaft is provided with cavity, the side of stirring shaft is provided with feed hole, second crystallization tank includes second shell, the volume of second shell is less than the volume of first shell, second shell is set in the bottom of first shell, first shell, second shell between being provided with baffle, the lower end of stirring shaft penetrates baffle and extends to second shell, the lower end of cavity is communicated with second shell, stirring shaft is sealingly rotatably connected with baffle, stirring rod is located in the inside of second shell, cooling circulation pipe is installed in the inside of second shell, multiple centrifuges are connected in the lower end outlet of second shell.

Description

Technical Field

[0001] This utility model relates to the field of chemical production technology, and in particular to a circulating accelerated crystallizer. Background Technology

[0002] In industrial production, sodium fluorosilicate is mainly prepared by reacting fluorosilicic acid (usually a byproduct of phosphate fertilizers or fluorochemicals) with sodium chloride (or sodium carbonate, sodium sulfate, or other sodium sources). A certain concentration of fluorosilicic acid solution and sodium salt solution (usually saturated or near-saturated solutions) are continuously or intermittently added to a crystallization tank according to a stoichiometric ratio. A double decomposition reaction occurs within the crystallization tank: `H₂SiF₆ + 2NaCl → Na₂SiF₆↓ + 2HCl` (when using NaCl) or `H₂SiF₆ + Na₂CO₃ → Na₂SiF₆↓ + H₂O + CO₂↑` (when using Na₂CO₃). The resulting sodium fluorosilicate (Na₂SiF₆) has low solubility in water (which increases with increasing temperature), and quickly reaches supersaturation in the reaction mixture, thus precipitating crystals.

[0003] Good stirring and temperature control can effectively prevent crystals from scaling on the tank walls and agitators, ensuring long-term stable operation of the equipment and reducing the frequency of shutdowns for cleaning and maintenance costs. Because the reaction crystallization tank has a large volume (to ensure production efficiency), precise temperature control is difficult during cooling crystallization.

[0004] Therefore, a circulating accelerated crystallizer is needed to solve the above-mentioned technical problems. Utility Model Content

[0005] This invention addresses the technical problems existing in the prior art by providing a circulating accelerated crystallizer.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: a circulating accelerated crystallizer, including a first crystallization tank and a second crystallization tank, wherein the second crystallization tank is installed at the lower end of the first crystallization tank; The first crystallization tank includes a first shell, a motor and a feed hopper are installed on the top of the first shell, a stirring shaft runs through the interior of the first shell, multiple stirring blades and stirring rods are fixed on the outside of the stirring shaft, a cavity is axially arranged inside the stirring shaft, a feed hole is provided on the side of the stirring shaft, the feed hole communicates with the cavity, and the stirring blades and feed hole are both located inside the first shell. The second crystallization tank includes a second shell, the volume of which is smaller than that of the first shell. The second shell is located at the bottom of the first shell. A partition is provided between the first shell and the second shell. The lower end of the stirring shaft passes through the partition and extends into the second shell. The lower end of the cavity is connected to the second shell. The stirring shaft is rotatably and sealed to the partition. The stirring rod is located inside the second shell. A cooling circulation pipe is installed inside the second shell. Multiple centrifuges are connected to the lower outlet of the second shell.

[0007] Preferably, in the above-described circulating accelerated crystallizer, a reflux pipe is connected between the lower end outlet of the second housing and the first housing, and a hydraulic pump is connected to the reflux pipe.

[0008] Preferably, in the above-described circulating accelerated crystallizer, a solenoid valve is installed at the lower end outlet of the second housing, and the lower end outlet of the second housing is connected to a plurality of centrifuges via a delivery pipe.

[0009] Preferably, in the above-described circulating accelerated crystallizer, a discharge port is provided on the bottom side of the first housing, and a sealing cap is installed at the discharge port.

[0010] Preferably, in the above-described circulating accelerated crystallizer, the cooling circulation pipe is spiral-shaped and fixed to the inner wall of the second housing.

[0011] Preferably, in the above-mentioned circulating accelerated crystallizer, one end of the cooling circulation pipe is connected to a liquid inlet, and the other end of the cooling circulation pipe is connected to a liquid outlet. The liquid inlet and the liquid outlet are both fixed on the outer wall of the second housing, and the liquid inlet and the liquid outlet are connected to an external cooling circulation system.

[0012] Preferably, in the above-described circulating accelerated crystallizer, the stirring rod is arranged parallel to the stirring shaft, and multiple connecting rods are fixedly connected between the stirring rod and the stirring shaft.

[0013] The beneficial effects of this utility model are as follows: By pouring the reaction raw materials into different feed hoppers, the raw materials enter the first crystallization tank, and the motor drives the stirring shaft to rotate. The solution is mixed and stirred by the stirring blades. The mixed solution enters the cavity through the feed hole and then enters the second crystallization tank through the lower port of the cavity. Since the volume of the second shell is small, it is easy to accurately control the temperature of the solution inside. Furthermore, the second crystallization tank can be stirred by the connecting rod and the stirring rod, so that the solution inside is evenly distributed, and a better crystallization effect can be achieved. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the internal structure of the first crystallization tank of this utility model; Figure 3 This is a schematic diagram of the internal structure of the second crystallization tank of this utility model.

[0015] The attached diagram lists the components represented by each number as follows: 1. Motor, 2. Hydraulic pump, 3. First crystallization tank, 31. Feed hopper, 32. Stirring shaft, 33. Stirring blade, 34. Sealing cover, 35. Cavity, 36. First shell, 37. Feed hole, 38. Baffle plate, 4. Second crystallization tank, 41. Cooling circulation pipe, 42. Stirring rod, 43. Connecting rod, 44. Liquid inlet, 45. Liquid outlet, 46. Second shell, 5. Conveying pipe, 6. Centrifuge. Detailed Implementation

[0016] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0017] like Figures 1-3 As shown, a circulating accelerated crystallizer includes a first crystallization tank 3 and a second crystallization tank 4, with the second crystallization tank 4 installed at the lower end of the first crystallization tank 3.

[0018] The first crystallization tank 3 includes a first housing 36. A motor 1 and multiple feed hoppers 31 are mounted on the top of the first housing 36. A stirring shaft 32 passes through the interior of the first housing 36. The first crystallization tank 3 and the second crystallization tank 4 share a single stirring shaft 32. The second crystallization tank 4 includes a second housing 46, the volume of which is smaller than that of the first housing 36. The second housing 46 is located at the bottom of the first housing 36. A partition 38 is provided between the first housing 36 and the second housing 46. The lower end of the stirring shaft 32 passes through the partition 38 and extends into the second housing 46. Multiple stirring blades 33 and stirring rods 42 are fixed to the outer side of the stirring shaft 32. The stirring shaft 32 has an axial cavity 35 inside, and a feed hole 37 is provided on the side of the stirring shaft 32. The feed hole 37 is connected to the cavity 35. The stirring blade 33 and the feed hole 37 are both located inside the first housing 36.

[0019] The lower end of cavity 35 communicates with the second housing 46, and the stirring shaft 32 is rotatably connected to the partition plate 38 in a sealed manner. The stirring rod 42 is located inside the second housing 46, and is arranged parallel to the stirring shaft 32. Multiple connecting rods 43 are fixedly connected between the stirring rod 42 and the stirring shaft 32. The stirring blades 33 are used to stir the first crystallization tank 3; the connecting rods 43 and the stirring rod 42 are used to stir the second crystallization tank 4. A return pipe is connected between the lower outlet of the second housing 46 and the first housing 36. A hydraulic pump 2 is connected to the return pipe. The hydraulic pump 2 can circulate the solution in the second crystallization tank 4 into the first crystallization tank 3 to ensure that the solution is fully mixed and to ensure the crystallization effect.

[0020] A cooling circulation pipe 41 is installed inside the second housing 46. The cooling circulation pipe 41 is spiral-shaped and fixed to the inner wall of the second housing 46. One end of the cooling circulation pipe 41 is connected to an inlet 44, and the other end is connected to an outlet 45. Both the inlet 44 and the outlet 45 are fixed to the outer wall of the second housing 46. The inlet 44 and the outlet 45 are connected to an external cooling circulation system to cool the second crystallization tank 4. Because the second housing 46 has a small volume, it is easy to accurately control the temperature of the solution inside. The second crystallization tank 4 can be stirred by the connecting rod 43 and the stirring rod 42 to make the solution inside evenly distributed, thus achieving a better crystallization effect.

[0021] Multiple centrifuges 6 are connected to the lower outlet of the second housing 46. A solenoid valve is installed at the lower outlet of the second housing 46, and the lower outlet of the second housing 46 is connected to the multiple centrifuges 6 through a conveying pipe 5. The solution after preliminary mixing and reaction in the first crystallization tank 3 enters the cavity 35 through the feed hole 37, and then enters the second crystallization tank 4 through the lower port of the cavity 35. After cooling and crystallization in the second crystallization tank 4, the solution enters the multiple centrifuges 6 through the lower outlet and the conveying pipe 5. The centrifuges 6 separate the crystal particles and the filtrate, and collect the filtrate through external equipment.

[0022] A discharge port is provided on the bottom side of the first housing 36, and a sealing cover 34 is installed at the discharge port. When cleaning the inside of the first housing 36, wastewater can be discharged through the discharge port.

[0023] Working principle: The reaction raw materials are poured into different feed hoppers 31. After the raw materials enter the first crystallization tank 3, the motor 1 drives the stirring shaft 32 to rotate. The stirring blades 33 mix and stir the solution. The mixed solution enters the cavity 35 through the feed hole 37 and enters the second crystallization tank 4 through the lower port of the cavity 35. The solution in the second crystallization tank 4 can be stirred by the connecting rod 43 and the stirring rod 42. After cooling and crystallization in the second crystallization tank 4, the solution enters multiple centrifuges 6 through the lower outlet and the conveying pipe 5. The centrifuges 6 separate the crystal particles and the filtrate and collect them through external equipment.

[0024] In the description of this utility model, it should be understood that the terms "upper," "lower," "left," and "right," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or a specific orientational structure and operation. Therefore, they should not be construed as limitations on this utility model. Furthermore, "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "multiple" means two or more.

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] The above description provides a detailed account of one embodiment of the present invention. However, this description is merely a preferred embodiment and should not be construed as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the claims of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A circulating accelerated crystallizer, characterized in that: It includes a first crystallization tank (3) and a second crystallization tank (4), with the second crystallization tank (4) installed at the lower end of the first crystallization tank (3); The first crystallization tank (3) includes a first housing (36), a motor (1) and a feed hopper (31) are installed on the top of the first housing (36), a stirring shaft (32) runs through the inside of the first housing (36), a number of stirring blades (33) and stirring rods (42) are fixed on the outside of the stirring shaft (32), a cavity (35) is axially arranged inside the stirring shaft (32), a feed hole (37) is arranged on the side of the stirring shaft (32), the feed hole (37) communicates with the cavity (35), and the stirring blades (33) and the feed hole (37) are both located inside the first housing (36); The second crystallization tank (4) includes a second shell (46), the volume of which is smaller than that of the first shell (36). The second shell (46) is located at the bottom of the first shell (36). A partition (38) is provided between the first shell (36) and the second shell (46). The lower end of the stirring shaft (32) passes through the partition (38) and extends into the second shell (46). The lower end of the cavity (35) is connected to the second shell (46). The stirring shaft (32) is rotatably connected to the partition (38). The stirring rod (42) is located inside the second shell (46). A cooling circulation pipe (41) is installed inside the second shell (46). Multiple centrifuges (6) are connected to the lower outlet of the second shell (46).

2. The circulating accelerated crystallizer according to claim 1, characterized in that: A return pipe is connected between the lower end outlet of the second housing (46) and the first housing (36), and a hydraulic pump (2) is connected to the return pipe.

3. The circulating accelerated crystallizer according to claim 1, characterized in that: A solenoid valve is installed at the lower outlet of the second housing (46), and the lower outlet of the second housing (46) is connected to a plurality of centrifuges (6) through a delivery pipe (5).

4. The circulating accelerated crystallizer according to claim 1, characterized in that: The bottom side of the first housing (36) is provided with a discharge port, and a sealing cover (34) is installed at the discharge port.

5. The circulating accelerated crystallizer according to claim 1, characterized in that: The cooling circulation pipe (41) is spiral-shaped and is fixed to the inner wall of the second housing (46).

6. The circulating accelerated crystallizer according to claim 5, characterized in that: One end of the cooling circulation pipe (41) is connected to an inlet (44), and the other end of the cooling circulation pipe (41) is connected to an outlet (45). The inlet (44) and outlet (45) are both fixed on the outer wall of the second housing (46), and the inlet (44) and outlet (45) are connected to an external cooling circulation system.

7. The circulating accelerated crystallizer according to claim 1, characterized in that: The stirring rod (42) is arranged parallel to the stirring shaft (32), and multiple connecting rods (43) are fixedly connected between the stirring rod (42) and the stirring shaft (32).

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