Crystallization cooler for continuous crystallization
By combining spiral and propeller-type stirring blades with an inverted conical shell, the problems of crystal sticking to the walls, settling to the bottom, and clogging of the discharge port in lithium hydroxide crystallizers are solved, achieving uniform stirring and crystal particle size control, thus improving crystallization quality.
Patent Information
- Application Number
- CN202520078191.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-14
- Publication Date
- 2025-12-30
- Estimated Expiration
- 2035-01-14
AI Technical Summary
In the production process of lithium hydroxide, existing crystallization coolers have problems such as poor stirring effect, which leads to crystal sticking to the wall and settling to the bottom, blockage of the discharge port, and crystal breakage when the stirring speed is too high, making it difficult to control the crystal particle size and distribution.
The design employs a combination of spiral and propeller impellers, along with an inverted conical shell and baffles, to achieve uniform dispersion of materials under low-speed stirring, avoiding crystal stratification and clogging. Temperature is controlled by a cooling water heat exchange jacket.
It achieves uniform mixing of materials at low stirring speeds, avoids crystal sticking to the walls and settling to the bottom, ensures smooth discharge, obtains ideal crystal particle size and distribution, and improves product quality consistency.
Smart Images
Figure CN223732145U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the technical field of chemical crystallization cooling equipment, and particularly relates to a crystallization cooler. BACKGROUND
[0002] Lithium hydroxide is an important inorganic compound, which has a wide application in the fields of batteries, ceramics, rubber and the like. In industrial production, the evaporation crystallization process of lithium hydroxide is a common production method. In the production process of lithium hydroxide monohydrate, the MVR evaporation crystallizer used belongs to the continuous crystallization category, that is, the continuous operation process of continuous addition of the material to be crystallized and continuous removal of the product of the crystallizer from the crystallizer, and the feeding and discharging are performed simultaneously. The lithium hydroxide aqueous solution is evaporated and concentrated to a certain solid content, and then gradually cooled to precipitate lithium hydroxide monohydrate crystals. The cooling of the lithium hydroxide slurry is performed in the crystallization cooler, and the precipitated crystals and the solution are in the same chamber. If the stirring effect is poor, the precipitated crystals will stick to the wall or sink to the bottom. The high solid content at the bottom of the crystallization cooler leads to the blockage of the discharge port of the crystallization cooler. After the new slurry is fed, the concentration of the upper slurry to be precipitated is low, and the solid-liquid suspension exists. There is an obvious concentration gradient in the crystallization cooler, which is not conducive to the control of the crystal size and morphology, and the crystal size distribution is wide. On the other hand, if the stirring speed is too high, the collision frequency of the precipitated crystals will increase, or the collision between the stirring blade and the crystals will cause the crystals to break and produce secondary nucleation, which is not conducive to the formation of large particles of crystals and the control of the crystal size distribution. Therefore, a crystallization cooler capable of fully stirring to ensure good stirring effect is needed. SUMMARY
[0003] The technical problem to be solved by the utility model is to overcome the deficiencies and defects mentioned in the above background technology, and to provide a continuous crystallization crystallization cooler capable of uniform stirring at a low stirring speed, solving the problems of crystal sticking to the wall and sinking to the bottom, improving the uniformity of the system material, and obtaining ideal crystal size and distribution.
[0004] To solve the above technical problems, the technical scheme provided by the utility model is as follows:
[0005] A continuous crystallization crystallization cooler, comprising a crystallization cooler shell for containing a solution to be crystallized, a cooling device for cooling the solution to be crystallized to crystallize, and a stirring device for stirring the solution to be crystallized, the stirring device comprising a stirring shaft arranged in the crystallization cooler shell and a stirring paddle arranged on the stirring shaft, the stirring paddle comprising a spiral stirring paddle for making the solution to be crystallized upward and a propeller stirring paddle for further dispersing the solution to be crystallized, the spiral stirring paddle being below the crystallization cooler shell and the propeller stirring paddle being above the spiral stirring paddle. The spiral stirring paddle is arranged to make the material move upward, and the propeller stirring paddle is arranged to make the material have upward and peripheral motion effects, so that the material is further dispersed after entering the action area of the propeller stirring paddle, ensuring uniform distribution of the material. Specifically, when stirring, the stirring shaft rotates to drive the lower spiral stirring paddle to mix the material, and the bottom layer of material is pulled upward along the blade to stir. In order to enhance the overall stirring effect, the material can be more evenly distributed at low stirring speed. The propeller stirring paddle is arranged above the spiral stirring paddle, so that the material flows upward along the inner wall during stirring. In this way, the separated crystals and the solution can be prevented from being stratified, and the problem of blockage of the discharge port caused by too high solid content of the bottom layer of material can be solved.
[0006] In the above-mentioned continuous crystallization crystallization cooler, preferably, the top end of the crystallization cooler shell is provided with a feed inlet, and the bottom is provided with a discharge outlet. The bottom of the crystallization cooler shell is in the shape of an inverted cone. The inverted cone shape makes it easier for the material to slide to the discharge outlet by gravity, improving the smoothness and efficiency of the discharge, reducing the possibility of blockage and poor flow during the discharge process, and the inverted cone-shaped bottom has no dead angle, facilitating cleaning and maintenance.
[0007] In the above-mentioned continuous crystallization crystallization cooler, preferably, the inner wall of the crystallization cooler shell is vertically provided with a flow baffle for increasing the turbulent degree of the agitated solution to be crystallized. This arrangement can eliminate the swirling of the solution in the crystallization cooler shell, increase the turbulent degree of the agitated solution, increase the degree of confusion when the solution flows, and improve the stirring effect.
[0008] In the above-mentioned continuous crystallization crystallization cooler, preferably, the stirring shaft is vertically arranged at the center line position inside the crystallization cooler shell, and the outside of the crystallization cooler shell is provided with a stirring motor for driving the stirring shaft to rotate. This arrangement can make the stirring paddle cover all areas inside the shell when rotating, realize uniform stirring of the material, effectively reduce the dead angle area during stirring, and ensure that all materials in the shell can be fully stirred.
[0009] Preferably, the propeller stirring blades are arranged at different heights.
[0010] Preferably, the spiral stirring blade comprises a shaft body and spiral blades arranged on the shaft body, and the shaft body is a reverse cone or a reverse conical frustum.
[0011] Preferably, the spiral blades are arranged in a pair and symmetrically distributed on the shaft body.
[0012] Preferably, the cooling device comprises a cooling water heat exchange jacket arranged on the outer wall of the crystallization cooler shell, a cooling water inlet arranged below the cooling water heat exchange jacket, and a cooling water outlet arranged above the cooling water heat exchange jacket.
[0013] The crystallization cooler for continuous crystallization can be used for cooling and crystallization of lithium hydroxide and other similar products.
[0014] Compared with the prior art, the crystallization cooler for continuous crystallization has the following advantages:
[0015] The spiral stirring blade and the propeller stirring blade are arranged, so that the crystallization solution can be stirred more uniformly at a low stirring speed after entering the crystallization cooler shell from the feed inlet, the separated crystals and the crystallization solution are prevented from being stratified, the uniformity of the system material is improved, the problems of crystal wall sticking, bottom sinking and blockage of the discharge port are solved, the continuous and stable operation of the equipment is ensured, ideal crystal size and distribution are obtained, and the quality consistency and stability of the product are improved. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.
[0017] Figure 1 The cross-sectional structure schematic diagram of the crystallization cooler for the continuous crystallization of the embodiment;
[0018] Figure 2 The top view of the propeller stirring paddle of the embodiment.
[0019] Legend
[0020] 1, discharge port; 2, drain; 3, cooling water inlet; 4, cooling water heat exchange jacket; 5, spiral stirring paddle; 51, shaft body; 52, spiral blade; 6, propeller stirring paddle; 7, baffle; 8, crystallization cooler shell; 9, stirring shaft; 10, feed inlet; 11, cooling water outlet; 12, stirring motor. DETAILED DESCRIPTION
[0021] In order to facilitate the understanding of the present application, the following will combine the drawings and the preferred embodiments of the specification to make a more comprehensive and detailed description of the present application, but the protection scope of the present application is not limited to the following specific embodiments.
[0022] It should be particularly noted that when a certain element is described as "fixed to, fixedly connected to, connected to or communicated to" another element, it can be directly fixed, fixedly connected, connected or communicated to another element, or indirectly fixed, fixedly connected, connected or communicated to another element through other intermediate connecting elements.
[0023] Unless otherwise defined, all the professional terms used in the following are the same as those commonly understood by those skilled in the art. The professional terms used in this paper are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present application.
[0024] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by existing methods.
[0025] Embodiment:
[0026] As Figure 1As shown, the continuous crystallization cooler of this embodiment includes a crystallization cooler shell 8 for containing the solution to be crystallized, a cooling device for cooling the solution to be crystallized to crystallize, and a stirring device for stirring the solution to be crystallized. The stirring device includes a stirring shaft 9 disposed in the crystallization cooler shell 8 and stirring blades disposed on the stirring shaft 9. The stirring blades include a spiral stirring blade 5 for causing the solution to be crystallized to rise and a propulsion stirring blade 6 for further dispersing the solution to be crystallized. The spiral stirring blade 5 is located below the crystallization cooler shell 8, and the propulsion stirring blade 6 is located above the spiral stirring blade 5.
[0027] In this embodiment, the crystallizer cooler shell 8 has a feed inlet 10 at the top and a discharge outlet 1 at the bottom, and the bottom of the crystallizer cooler shell 8 is inverted conical. A flushing port may also be provided at the top of the crystallizer cooler shell 8.
[0028] In this embodiment, a baffle plate 7 is vertically installed on the inner wall of the crystallizer shell 8 to increase the turbulence of the agitated solution to be crystallized. The baffle plate 7 can be a vertical baffle, and two baffle plates can be installed vertically on the inner side wall of the crystallizer shell 8. In other embodiments, the number and position can be set according to the actual situation.
[0029] In this embodiment, the stirring shaft 9 is vertically arranged at the center line position inside the crystallizer housing 8, and a stirring motor 12 for driving the stirring shaft 9 to rotate is provided outside the crystallizer housing 8.
[0030] In this embodiment, multiple propulsion-type stirring blades 6 are arranged at different height intervals. For example... Figure 2 As shown, the propeller-type stirring blade 6 can be a five-bladed propeller-type stirring blade, and two can be arranged at intervals, so that the stirring device forms a three-layer stirring. The lower layer uses a spiral stirring blade 5, and the upper and middle layers use two coaxial propeller-type stirring blades 6. When the solution to be crystallized enters the crystallizer shell 8 from the feed inlet 10, it can be more evenly distributed at a low stirring speed, avoiding the separation of the precipitated crystals from the solution, and avoiding the collision between the stirring blades and the crystals caused by high-speed stirring, which would lead to crystal breakage and secondary nucleation.
[0031] In this embodiment, the spiral stirring blade 5 includes a shaft 51 and spiral blades 52 disposed on the shaft 51. The shaft 51 is an inverted cone or an inverted frustum.
[0032] In this embodiment, a pair of spiral blades 52 are provided, symmetrically distributed on the shaft 51.
[0033] In this embodiment, the cooling device includes a cooling water heat exchange jacket 4 disposed on the outer wall of the crystallizer shell 8. A cooling water inlet 3 is disposed below the cooling water heat exchange jacket 4, and a cooling water outlet 11 is disposed above the cooling water heat exchange jacket 4. A drain outlet 2 is disposed at the bottom end of the cooling water heat exchange jacket 4.
[0034] In the embodiment, taking lithium hydroxide cooling crystallization as an example, the specific operation steps are as follows: firstly, 18-25 DEG C cooling circulating water is introduced from the cooling water inlet 3 of the cooling water heat exchange jacket 4, then a certain amount of material is introduced from the feed inlet 10 of the crystallization cooler shell 8, the stirring motor 12 is started, and the frequency of the motor can be adjusted, the stirring speed is 25-50 r / min, the separated crystals are subjected to the double helical stirring force of the helical stirring blade 5 and rise, the rising material enters the action area of the propeller stirring blade 6 and is further dispersed, so that the material can be uniformly distributed, after a certain residence time, the material is taken out from the discharge port 1 of the crystallization cooler shell 8.
[0035] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can be variously changed and modified. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A continuously crystallizing crystallization cooler, comprising a crystallization cooler housing (8) for accommodating a solution to be crystallized, a cooling device for cooling the solution to be crystallized for crystallization, and a stirring device for stirring the solution to be crystallized, characterized in that The stirring device comprises a stirring shaft (9) arranged in the crystallization cooler shell (8) and stirring paddles arranged on the stirring shaft (9), the stirring paddles comprise a spiral stirring paddle (5) for making the solution to be crystallized to be in an upward trend and a propelling stirring paddle (6) for further dispersing the solution to be crystallized, the spiral stirring paddle (5) is located below the crystallization cooler shell (8), and the propelling stirring paddle (6) is located above the spiral stirring paddle (5).
2. The continuous crystallization crystallization cooler according to claim 1, characterized in that, The crystallization cooler shell (8) is provided with a feeding port (10) at the top end and a discharging port (1) at the bottom, and the bottom of the crystallization cooler shell (8) is in a reverse conical shape.
3. The continuous crystallization crystallization cooler of claim 1, wherein, A flow baffle (7) for increasing the turbulent degree of the agitated solution to be crystallized is arranged vertically on the inner wall of the crystallization cooler shell (8).
4. The continuous crystallization crystallization cooler of claim 1, wherein, The stirring shaft (9) is arranged vertically at the central axis position inside the crystallization cooler shell (8), and an agitator motor (12) for driving the stirring shaft (9) to rotate is arranged outside the crystallization cooler shell (8).
5. The continuous crystallization crystallization cooler of claim 1, wherein, The propelling stirring paddles (6) are arranged at different heights.
6. The continuous crystallization crystallization cooler of claim 1, wherein, The spiral stirring paddle (5) comprises a shaft body (51) and spiral blades (52) arranged on the shaft body (51), and the shaft body (51) is in a reverse conical or reverse conical frustum shape.
7. The continuous crystallization crystallization cooler of claim 6, characterized in that, The spiral blades (52) are arranged in a pair and symmetrically distributed on the shaft body (51).
8. The continuous crystallization crystallization cooler according to any one of claims 1-7, characterized in that, The cooling device comprises a cooling water heat exchange jacket (4) arranged on the outer wall of the crystallization cooler shell (8), a cooling water inlet (3) is arranged below the cooling water heat exchange jacket (4), and a cooling water outlet (11) is arranged above the cooling water heat exchange jacket (4).