A crystallization and crystal growing apparatus

Abstract

The utility model discloses a crystallization device, including continuous crystallizer, the discharge gate of continuous crystallizer is connected with circulating pump, and the discharge gate of circulating pump is connected with the feed inlet of crystallization crystallization kettle and the backflow port of continuous crystallizer through three -way valve, the inside installation temperature sensor of crystallization crystallization kettle is equipped with cooling water inlet valve and cooling water outlet valve on the clamping sleeve, and the outside is equipped with the clamping sleeve, temperature sensor, cooling water inlet valve and cooling water outlet valve all are connected with controller signal. The utility model provides stable crystallization environment, and the small crystal is prompted to grow continuously to increase the product crystal grain size and improve its uniformity significantly, and the obtained large particle crystal has good flowability and is easy to separate, and the efficiency of subsequent centrifugal, drying procedure is improved greatly, the device structure design of the utility model is flexible, and intermittent operation can be realized, and the parallel configuration of multiple crystallization crystallization kettle can realize the continuous production of whole process, thereby guaranteeing the stability of production process and improving overall efficiency.

Description

Technical Field

[0001] This utility model relates to the field of chemical production equipment, and in particular to a crystallization and growth device that can effectively control crystal particle size and is suitable for highly soluble substances. Background Technology

[0002] Sodium hypophosphite is an important chemical product widely used in electroless plating, food additives, and pharmaceuticals. Crystallization is a crucial step in the production of sodium hypophosphite, determining its final physical form.

[0003] Currently, vacuum cooling crystallization devices are commonly used in the production of sodium hypophosphite. However, due to the high solubility of sodium hypophosphite and its extreme sensitivity to temperature changes, the solution rapidly reaches supersaturation during cooling, releasing a large number of fine crystal nuclei. This results in fine-grained sodium hypophosphite crystals with poor flowability, severely impacting the efficiency and effectiveness of subsequent solid-liquid separation and drying processes, thus hindering overall production capacity improvement and product quality stability.

[0004] Therefore, there is an urgent need for a crystallization device that can effectively increase the particle size of sodium hypophosphite crystals and improve the physical properties of the product. Utility Model Content

[0005] This invention provides a crystallization and growth device to solve the aforementioned problem caused by the excessively rapid cooling rate of sodium hypophosphite during vacuum cooling crystallization in the prior art.

[0006] To solve the above-mentioned technical problems, this utility model provides a crystallization and crystal growth device, including: a continuous crystallizer, at least one crystallization and crystal growth vessel, and a temperature control system; The outlet of the continuous crystallizer is connected to the inlet of the circulating pump via a pipeline, and the outlet of the circulating pump is connected to the inlet of the crystallization reactor and the reflux port of the continuous crystallizer via a switching valve. The bottom of the crystallization and growth vessel is equipped with a discharge pipe, an agitator inside, and a jacket outside. The jacket is equipped with a cooling water inlet valve and a cooling water outlet valve. The temperature control system includes a controller and a temperature sensor installed inside the crystallization reactor. The temperature sensor, cooling water inlet valve, and cooling water outlet valve are all connected to the controller. The controller adjusts the opening of the cooling water inlet valve and / or the cooling water outlet valve according to the detection value of the temperature sensor to maintain the temperature inside the crystallization reactor within a set range.

[0007] In a preferred embodiment of this utility model, the number of crystallization and growth vessels is two; the switching valve is a three-way switching valve, and its two outlets are respectively connected to the feed ports of the two crystallization and growth vessels.

[0008] In a preferred embodiment of this utility model, the bottom of the crystallization growth vessel has a conical structure.

[0009] In a preferred embodiment of this utility model, the cone angle of the cone structure is 60°.

[0010] In a preferred embodiment of the present invention, the discharge pipe is located at the lowest point of the bottom of the conical structure.

[0011] In a preferred embodiment of the present invention, the stirrer includes a stirring shaft and double-layer stirring blades disposed on the stirring shaft.

[0012] In a preferred embodiment of the present invention, the feed pipe of the continuous crystallizer is provided with a mass flow meter and a regulating valve for controlling the flow rate.

[0013] In a preferred embodiment of this invention, the device is suitable for crystallization of sodium hypophosphite solution.

[0014] The beneficial effects of this utility model are as follows: This utility model provides a crystal growth device by combining a continuous crystallizer with a crystal growth vessel with precise temperature control, which provides a stable crystal growth environment, promotes the continuous growth of fine crystals, thereby significantly increasing the product crystal particle size and improving its uniformity. The resulting large crystal particles have good flowability and are easy to separate, which greatly improves the efficiency of subsequent centrifugation and drying processes. The device structure of this utility model is flexible, and it can realize intermittent operation or continuous production of the entire process by parallel configuration of multiple crystal growth vessels, thereby ensuring the stability of the production process and improving the overall efficiency. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural schematic diagram of a preferred embodiment of a crystallization and crystal growth device according to the present invention; The components in the attached diagram are labeled as follows: 10. Continuous crystallizer; 11. Mass flow meter; 12. Control valve; 20. Crystallization reactor; 21. Valve; 30. Circulating pump; 40. Three-way switching valve; 50. Agitator; 51. Agitator shaft; 52. Double-layer agitator blades; 60. Jacket; 61. Cooling water inlet valve; 62. Cooling water outlet valve; 70. Temperature sensor; 80. Centrifuge; 90. Motor. Detailed Implementation

[0016] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention.

[0017] Example 1 This utility model discloses a crystal growth device.

[0018] The following examples illustrate the application of this device to the crystallization of sodium hypophosphite solution.

[0019] The crystallization and growth device includes: a continuous crystallizer 10, two crystallization and growth kettles 20, and a temperature control system.

[0020] Specifically, the continuous crystallizer 10 is a conventional vacuum-cooled crystallizer in the art, with an inlet and an outlet at its bottom. The inlet pipe is equipped with a mass flow meter 11 and a regulating valve 12 for controlling the flow rate of the sodium hypophosphite solution. The outlet is connected to the inlet of a circulating pump 30 via an outlet pipe. The outlet of the circulating pump 30 is connected to the inlet of a three-way switching valve 40. This three-way switching valve 40 has one inlet and three outlets, which are respectively connected via pipes to: the reflux port at the top of the continuous crystallizer 10 and the inlets of the two crystallization tanks 20. By controlling the position of the three-way switching valve 40, the crystal slurry from the circulating pump 30 can be selectively diverted to one of the three destinations mentioned above.

[0021] The bottom of the crystallization reactor 20 is a 60° conical structure, which facilitates the collection of crystal slurry. A discharge pipe 21 with a valve 21 is located at the lowest point of the cone bottom for discharging the crystal slurry after crystallization to subsequent separation equipment. An agitator 50 is located at the center of the crystallization reactor 20. This agitator 50 includes a stirring shaft 51 and double-layered stirring blades 52 fixed on the shaft. The agitator 50 is driven by a motor 90, and its rotation speed is preferably controlled within the range of 30-50 r / min. This rotation speed ensures uniform crystal slurry and prevents crystal sedimentation, while also avoiding excessive shear force that could damage crystal growth.

[0022] The crystallization reactor 20 is equipped with a jacket 60, on which a cooling water inlet valve 61 and a cooling water outlet valve 62 are connected for introducing cooling water to exchange heat with the material inside the reactor. A temperature sensor 70 is installed on the side wall of the crystallization reactor 20 to monitor the temperature of the crystal slurry inside the reactor in real time.

[0023] The temperature control system comprises a temperature sensor 70, a cooling water inlet valve 61, a cooling water outlet valve 62, and a controller. The temperature sensor 70, cooling water inlet valve 61, and cooling water outlet valve 62 are all connected to the controller via signal lines (shown as dashed lines in the figure). The controller is preferably a commonly used industrial PLC (Programmable Logic Controller) with a preset temperature range for the crystal growth process. For the sodium hypophosphite solution crystallization in this embodiment, this temperature is set to 50℃ ± 2℃.

[0024] Taking sodium hypophosphite crystallization as an example, the working principle or process of this invention is as follows: Continuous crystallization stage: A saturated sodium hypophosphite solution enters the continuous crystallizer 10 through the bottom pipe. Feeding stops when the liquid level reaches the set height, and the vacuum system is activated for cooling and crystallization. When the material temperature inside the crystallizer drops to approximately 60-65℃, the system enters continuous operation mode. Open the mass flow meter 11 and regulating valve 12 on the feed pipeline to allow the sodium hypophosphite solution to continuously enter the continuous crystallizer 10 at a constant flow rate; at the same time, start the circulation pump 30 to pump the crystal slurry containing a large number of fine crystals out of the continuous crystallizer 10.

[0025] Switching and Crystallization Stage: The crystal slurry pumped by the circulating pump 30 enters one of the crystallization growth vessels via the three-way switching valve 40, as shown in the attached diagram on the left. At this time, the agitator 50 of the crystallization growth vessel 20 operates at a speed of 40 r / min. The temperature sensor 70 monitors the temperature inside the crystallization growth vessel in real time and transmits the signal to the PLC controller. The PLC controller compares the measured temperature with the set value (50℃), and through PID calculation, outputs a control signal to adjust the opening of the cooling water inlet valve 61, thereby controlling the cooling water flow rate and precisely maintaining the temperature inside the vessel at a stable state of approximately 50℃. In this mild and controllable environment, the sodium hypophosphite crystals in the crystal slurry can grow slowly (i.e., "crystallization"), and the particle size gradually increases.

[0026] Alternating discharge and continuous operation: After the crystal growth process in the left crystal growth vessel 20 lasts for approximately 1-2 hours, the three-way switching valve 40 is operated to switch the crystal slurry flow to the ready crystal growth vessel on the right. Subsequently, the valve of the discharge pipe 21 at the bottom of the left vessel is opened to discharge the sodium hypophosphite crystal slurry, which has completed crystal growth and increased crystal size, to the centrifuge 80 for separation. The crystal growth vessel on the right repeats the above crystal growth process. The two crystal growth vessels 20 alternately perform feeding, crystal growth, and discharge operations in this way, ensuring that the front-end continuous crystallizer 10 can achieve truly continuous and uninterrupted operation.

[0027] The present invention provides a crystallization and crystal growth device that effectively increases the particle size of sodium hypophosphite crystals through the functional combination and synergistic operation of a continuous crystallizer 10 and a crystallization and crystal growth vessel 20.

[0028] In addition, the number of crystallization kettles can be increased according to the production scale, and the crystallization temperature can be adjusted according to the properties of the material to be crystallized.

[0029] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A crystallization and growth apparatus, characterized in that, include: Continuous crystallizer, at least one crystallization and growth vessel, and temperature control system; The outlet of the continuous crystallizer is connected to the inlet of the circulating pump via a pipeline, and the outlet of the circulating pump is connected to the inlet of the crystallization reactor and the reflux port of the continuous crystallizer via a switching valve. The bottom of the crystallization and growth vessel is equipped with a discharge pipe, an agitator inside, and a jacket outside. The jacket is equipped with a cooling water inlet valve and a cooling water outlet valve. The temperature control system includes a controller and a temperature sensor installed inside the crystallization reactor. The temperature sensor, cooling water inlet valve, and cooling water outlet valve are all connected to the controller. The controller adjusts the opening of the cooling water inlet valve and / or the cooling water outlet valve according to the detection value of the temperature sensor to maintain the temperature inside the crystallization reactor within a set range.

2. The crystallization and growth apparatus according to claim 1, characterized in that, The number of crystallization and growth vessels is two; the switching valve is a three-way switching valve, and its two outlets are respectively connected to the feed ports of the two crystallization and growth vessels.

3. The crystallization and growth apparatus according to claim 1, characterized in that, The bottom of the crystallization and growth vessel has a conical structure.

4. The crystallization and growth apparatus according to claim 3, characterized in that, The cone angle of the cone structure is 60°.

5. A crystallization and growth apparatus according to claim 3, characterized in that, The discharge pipe is located at the lowest point of the bottom of the conical structure.

6. The crystallization and growth apparatus according to claim 1, characterized in that, The agitator includes a stirring shaft and double-layered stirring blades disposed on the stirring shaft.

7. The crystallization and growth apparatus according to claim 1, characterized in that, The feed line of the continuous crystallizer is equipped with a mass flow meter and a regulating valve for controlling the flow rate.

8. A crystallization and growth apparatus according to any one of claims 1-7, characterized in that, The device is suitable for crystallization and growth of sodium hypophosphite solution.

Images