Thiourea crystallization kettle

Abstract

The invention discloses a thiourea crystallization kettle which comprises a kettle body, the interior of the kettle body is hollow to form a thiourea crystallization cavity, a temperature control unit capable of adjusting the temperature is arranged in the thiourea crystallization cavity, the thiourea crystallization kettle further comprises a drainage structure arranged in the thiourea crystallization cavity, and the drainage structure comprises an annular drainage cylinder; the drainage cylinder divides the thiourea crystallization cavity into an inner reaction cavity and an outer reaction cavity which are communicated with each other, a drainage assembly is arranged in the inner reaction cavity, the drainage assembly can drive a thiourea solution to circularly flow between the inner reaction cavity and the outer reaction cavity, and the ratio of the vertical height of the drainage cylinder to the vertical height of the thiourea crystallization cavity is not less than 50%. The uniformity of the particle size of thiourea crystals separated out from the thiourea solution is improved; and as the ratio of the vertical height of the drainage cylinder to the vertical height of the thiourea crystallization cavity is not less than 50%, the flow uniformity of the thiourea crystals is improved, and the possibility that the thiourea crystals are accumulated at the bottom of the kettle body is reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of crystallization equipment, and specifically relates to a thiourea crystallization kettle. Background Art

[0002] As an important chemical reagent, thiourea can be used as a reducing agent, decolorizing agent and addition agent. It can be used to prepare transfer colloids and form protonated colloids. It is also used as a synthetic raw material for drugs such as chloramphenicol. It plays an important role in the field of organic synthesis.

[0003] The preparation of thiourea usually includes the ammonium thiocyanate method, the diazomethane method and the lime nitrogen method. The most commonly used method is the lime ammonia method. Lime nitrogen and hydrogen sulfide gas undergo absorption synthesis reaction in a synthesis reactor to obtain a thiourea solution. The thiourea solution is then placed in a crystallization kettle for cooling and crystallization to obtain thiourea crystals, which are then dried to obtain the thiourea finished product. In traditional technology, a urea crystallizer is usually used to crystallize thiourea solution. However, due to the large difference in molecular structure between thiourea and urea, specifically, the molecular formula of thiourea is (NH2)2CS, which is an organic compound; and the molecular formula of urea is (NH2)2CO, which is an inorganic compound. There is a large difference in their molecular structures. Using a urea crystallizer to crystallize thiourea will cause the thiourea crystals obtained after the thiourea solution is condensed to accumulate at the bottom of the crystallizer, resulting in problems such as poor crystal form and uneven particle size. Therefore, how to design a device for crystallization of thiourea solution has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present application provides a thiourea crystallization kettle to solve the technical problems of uneven thiourea crystal particle size and poor crystal form after thiourea solution crystallizes in the prior art.

[0005] The technical solution adopted in this application is:

[0006] A thiourea crystallization kettle comprises a kettle body, wherein the interior of the kettle body is hollow to form a thiourea crystallization chamber, wherein a temperature control unit capable of adjusting the temperature is arranged in the thiourea crystallization chamber, and further comprising a drainage structure arranged in the thiourea crystallization chamber, wherein the drainage structure comprises an annular drainage cylinder, wherein the drainage cylinder divides the thiourea crystallization chamber into an inner reaction chamber and an outer reaction chamber which are interconnected, wherein a drainage component is arranged in the inner reaction chamber, wherein the drainage component can drive a thiourea solution to circulate between the inner reaction chamber and the outer reaction chamber, and wherein the ratio of the vertical height of the drainage cylinder to the vertical height of the thiourea crystallization chamber is not less than 50%.

[0007] The thiourea crystallization kettle described in this application also includes the following additional technical features:

[0008] The ratio of the vertical height of the drainage tube to the vertical height of the thiourea crystallization chamber is 55%-75%.

[0009] The drainage tube has a first opening at the top and a second opening at the bottom. The projections of the first opening and the second opening on the horizontal plane are both circular. The area ratio of the first opening to the second opening is 1.2-1.4.

[0010] The guide tube is provided with a first arc-shaped guide portion and a second arc-shaped guide portion at the first opening and the second opening, respectively, which are notched toward the outer reaction chamber.

[0011] The top and bottom of the kettle body are respectively provided with a third arc-shaped guide portion and a fourth arc-shaped guide portion which are concave toward the outer reaction chamber, and the tangent line of any point on the first arc-shaped guide portion passes through the third arc-shaped guide portion, and / or the tangent line of any point on the second arc-shaped guide portion passes through the fourth arc-shaped guide portion.

[0012] The temperature control unit comprises a plurality of temperature regulating rods which are arranged at intervals in the outer reaction chamber and extend in a vertical direction, and projections of at least some of the plurality of temperature regulating rods on a horizontal plane fall on the circumference of the same circle.

[0013] The distances between any two adjacent temperature regulating rods whose projections fall on the circumference of the same circle are equal.

[0014] The temperature control unit further includes an upper temperature regulating ring located at the top of the temperature regulating rod and a lower temperature regulating ring located at the bottom of the temperature regulating rod, and the projections of the upper temperature regulating ring and the lower temperature regulating ring on the horizontal plane overlap.

[0015] The drainage component includes a driving motor arranged at the bottom of the kettle body and a rotating column connected to the driving motor, the driving motor can drive the rotating column to rotate, and at least one drainage fan blade is installed on the rotating column, and the blade extension direction of the drainage fan blade is perpendicular to the axial direction of the drainage tube.

[0016] The number of the drainage blades is multiple, and the angles between two adjacent drainage blades are equal.

[0017] Due to the adoption of the above technical solution, the beneficial effects achieved by this application are as follows:

[0018] 1. The thiourea crystallization kettle of the present application is provided with a thiourea crystallization chamber inside the kettle body, and a drainage structure including an annular drainage tube is provided in the thiourea crystallization chamber to divide the thiourea crystallization chamber into an inner reaction chamber and an outer reaction chamber, and a drainage component is also provided in the inner reaction chamber. Under the catalytic action of the drainage component, the thiourea solution circulates in the inner reaction chamber and the outer reaction chamber and gradually condenses and crystallizes under the temperature control action of the temperature control unit. The thiourea crystals after partial solidification continue to circulate between the inner reaction chamber and the outer reaction chamber with the thiourea solution under the drainage action of the drainage component, thereby avoiding the accumulation of a large number of thiourea crystals at the bottom of the kettle body. The urea thioate crystals are concentrated in the annular space between the drainage tube and the kettle body, thereby reducing the interference of the large amount of accumulation of urea thioate crystals on the crystallization of the urea thioate solution, so that the urea thioate solution is always in a roughly stable and smooth motion state during the circulating flow crystallization process, thereby improving the uniformity of the particle size of the urea thioate crystals precipitated from the urea thioate solution; and since the ratio of the vertical height of the drainage tube to the vertical height of the urea thioate crystallization chamber is not less than 50%, such a setting reduces the flow velocity of the condensed urea thioate crystals in the annular space between the drainage tube and the kettle body to a certain extent, improves the flow uniformity of the urea thioate crystals, and further reduces the possibility of the urea thioate crystals accumulating at the bottom of the kettle body.

[0019] 2. As a preferred embodiment of the present application, the ratio of the vertical height of the drainage tube to the vertical height of the thiourea crystallization chamber is 55%-75%. Such a configuration further reduces the accumulation of thiourea crystals in the inner reaction chamber, especially at the axial position of the corresponding kettle body, and more thiourea crystals are dispersed to the top of the thiourea crystallization chamber, making the distribution of thiourea crystals more uniform and dispersed, further reducing the effect of local accumulation of thiourea crystals on the crystallization of thiourea solution, and helping to improve the uniformity and stability of thiourea crystal precipitation.

[0020] 3. As a preferred embodiment of the present application, the drainage tube has a first opening at the top and a second opening at the bottom, the projections of the first opening and the second opening on the horizontal plane are both circular, and the area ratio of the first opening to the second opening is 1.2-1.4. Such a configuration, on the one hand, allows the thiourea solution to circulate along the path of the inner reaction chamber, the first opening, the outer reaction chamber, and the second opening in the thiourea crystallization chamber, thereby reducing the probability of liquid convection impact of the thiourea solution during the flow process, thereby reducing the occurrence of turbulence caused by the convection impact of the thiourea solution, and further improving the uniformity of thiourea crystallization; on the other hand, the area ratio of the first opening to the second opening is 1.2-1.4, further improving the aggregation amount of thiourea crystals in the upper part of the thiourea crystallization chamber, thereby further reducing the accumulation of thiourea crystals at the bottom of the thiourea crystallization chamber, which helps to improve the crystallization uniformity of the thiourea solution.

[0021] 4. As a preferred embodiment of the present application, the drainage tube is provided with a first arc-shaped guide portion and a second arc-shaped guide portion which are notched toward the outer reaction chamber at the first opening and the second opening, respectively. With such arrangement, on the one hand, when the thiourea solution flows from the inner reaction chamber to the outer reaction chamber, the thiourea solution near the drainage tube slowly changes its flow direction under the action of the first arc-shaped guide portion and the second arc-shaped guide portion, so that the thiourea solution gradually moves in the direction toward the outer reaction chamber, so that it can be more evenly diffused into the outer reaction chamber after entering the outer reaction chamber, and the flow velocity of the thiourea solution at the connection point between the inner reaction chamber and the outer reaction chamber caused by the change of movement direction is reduced, so as to maintain the uniformity of the circulation of the thiourea solution, which is conducive to improving the crystal uniformity and particle size consistency of the thiourea crystals precipitated by the thiourea.

[0022] 5. As a preferred embodiment of the present application, the top and bottom of the kettle body are respectively provided with a third arc-shaped guide portion and a fourth arc-shaped guide portion which are concave toward the outer reaction chamber, and the tangent line of any point on the first arc-shaped guide portion passes through the third arc-shaped guide portion, and / or the tangent line of any point on the second arc-shaped guide portion passes through the fourth arc-shaped guide portion. Since the thiourea solution will change its flow direction during the flow from the inner reaction chamber to the outer reaction chamber and from the outer reaction chamber to the inner reaction chamber, if the thiourea solution after the flow direction is changed directly hits the wall of the drainage tube or the inner wall of the kettle body, it will cause the thiourea solution to collapse and transform into multiple streams of fluid. The multiple streams of fluid collide with each other and disrupt the uniformity of the flow of the thiourea solution, so that the flow rate of this part of the thiourea solution is different from that of the rest of the thiourea solution, and even turbulence is stimulated inside the thiourea solution, resulting in differences in particle size and uniformity of the precipitated thiourea crystals; and the tangent line of any point on the first arc-shaped guide portion is changed to the inner wall of the drainage tube or the inner wall of the kettle body. The first arc-shaped guide portion has a plurality of thiourea solutions, each of which has a plurality of thiourea solutions. ... After the flow direction changes, the thiourea solution directly impacts the wall of the drainage tube or the inner wall of the kettle body, thereby avoiding the liquid collapse of the thiourea solution and the drastic changes in the flow direction and flow rate caused by the violent impact, which helps to improve the uniformity of the circulation flow of the thiourea solution and provide a guarantee for the uniformity of the thiourea crystal particle size; similarly, the second arc-shaped guide portion is set so that the tangent of any point on it passes through the fourth arc-shaped guide portion. When part of the thiourea solution moves along the outer wall of the drainage tube, the flow direction will be changed from a straight line to a curve under the guidance of the second arc-shaped guide portion, and part of the thiourea solution will break away from the second arc-shaped guide portion and continue to move along the tangent direction. Since the tangent of any point on the second arc-shaped guide portion passes through the fourth arc-shaped guide portion, the thiourea solution that escapes from any point on the second arc-shaped guide portion can move to the fourth arc-shaped guide portion along the tangent direction, change its movement direction under the guidance of the fourth arc-shaped guide portion, and be guided forward, thereby preventing the thiourea solution from directly impacting the wall of the drainage tube or the inner wall of the kettle body after the flow direction is changed, thereby avoiding the liquid collapse of the thiourea solution caused by violent impact and the drastic change of flow direction and flow velocity, which is helpful to improve the uniformity of the circulation flow of the thiourea solution and provide guarantee for the uniformity of the thiourea crystal particle size. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0024] Figure 1 This is a cross-sectional view of a thiourea crystallization kettle according to one embodiment of the present application.

[0025] in:

[0026] 1 kettle body;

[0027] 2 thiourea crystallization chamber, 21 inner reaction chamber, 22 outer reaction chamber;

[0028] 3 temperature control unit, 31 temperature regulating rod, 32 upper temperature regulating ring, 33 lower temperature regulating ring;

[0029] 4 drainage tube, 41 first opening, 42 second opening;

[0030] 5 a first arc-shaped guide portion;

[0031] 6 second arc-shaped guide portion;

[0032] 7 a third arc-shaped guide portion;

[0033] 8 fourth arc-shaped guide portion;

[0034] 9 rotating column;

[0035] 10 drainage blades. DETAILED DESCRIPTION

[0036] In order to more clearly illustrate the overall concept of the present application, a detailed description is given below in an illustrative manner in conjunction with the accompanying drawings.

[0037] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below. It should be noted that the embodiments of the present application and the features in each embodiment may be combined with each other without conflict.

[0038] In addition, in the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0039] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] In the present application, unless otherwise clearly specified and limited, a first feature "above" or "below" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0041] like Figure 1 As shown, a thiourea crystallization kettle comprises a kettle body 1, wherein the kettle body 1 is hollow inside to form a thiourea crystallization chamber 2, wherein a temperature control unit 3 capable of adjusting the temperature is provided in the thiourea crystallization chamber 2, and further comprising a drainage structure provided in the thiourea crystallization chamber 2, wherein the drainage structure comprises an annular drainage tube 4, wherein the drainage tube 4 divides the thiourea crystallization chamber 2 into an inner reaction chamber 21 and an outer reaction chamber 22 which are interconnected, wherein a drainage component is provided in the inner reaction chamber 21, wherein the drainage component can drive the thiourea solution to circulate between the inner reaction chamber 21 and the outer reaction chamber 22, and wherein the ratio of the vertical height of the drainage tube 4 to the vertical height of the thiourea crystallization chamber 2 is not less than 50%.

[0042] The thiourea crystallization kettle of the present application is provided with a thiourea crystallization chamber 2 inside the kettle body 1, and a drainage structure including an annular drainage tube 4 is provided in the thiourea crystallization chamber 2 to divide the thiourea crystallization chamber 2 into an inner reaction chamber 21 and an outer reaction chamber 22, and a drainage component is also provided in the inner reaction chamber 21. Under the catalytic action of the drainage component, the thiourea solution circulates in the inner reaction chamber 21 and the outer reaction chamber 22 and gradually condenses and crystallizes under the temperature adjustment action of the temperature control unit 3. The thiourea crystals after partial solidification continue to circulate between the inner reaction chamber 21 and the outer reaction chamber 22 with the thiourea solution under the drainage action of the drainage component, thereby avoiding a large number of thiourea crystals in the inner reaction chamber 21 and the outer reaction chamber 22. The accumulation at the bottom of the kettle body 1 reduces the interference of a large amount of accumulation of thiourea crystals on the crystallization of the thiourea solution, so that the thiourea solution is always in a roughly stable and smooth motion state during the circulating flow crystallization process, thereby improving the uniformity of the particle size of the thiourea crystals precipitated from the thiourea solution; and since the ratio of the vertical height of the drainage tube 4 to the vertical height of the thiourea crystallization chamber 2 is not less than 50%, such a setting reduces the flow velocity of the condensed thiourea crystals in the annular gap between the drainage tube 4 and the kettle body 1 to a certain extent, improves the flow uniformity of the thiourea crystals, and further reduces the possibility of accumulation of thiourea crystals at the bottom of the kettle body 1.

[0043] Figure 1 H1 shown in the figure is the vertical height of the drainage tube 4, H2 is the vertical height of the thiourea crystallization chamber 2, and H1≥0.5H2.

[0044] The present application does not limit the installation method of the drainage tube 4. In one embodiment, a plurality of first positioning grooves are provided on the drainage tube 4, and a plurality of second positioning grooves are provided on the side wall of the kettle body 1. The drainage tube 4 and the kettle body 1 are detachably connected by inserting the positioning rods into the first positioning grooves and the second positioning grooves respectively.

[0045] As a preferred embodiment of the present application, Figure 1 As shown, the ratio of the vertical height of the drainage tube 4 to the vertical height of the thiourea crystallization chamber 2 is 55%-75%. Such a configuration further reduces the accumulation of thiourea crystals in the inner reaction chamber 21, especially at the axial position corresponding to the kettle body 1, and more thiourea crystals are dispersed to the top of the thiourea crystallization chamber 2, making the distribution of thiourea crystals more uniform and dispersed, further reducing the influence of local accumulation of thiourea crystals on the crystallization of thiourea solution, which helps to improve the uniformity and stability of thiourea crystal precipitation. Figure 1 H1 shown in the figure is the vertical height of the drainage tube 4, H2 is the vertical height of the thiourea crystallization chamber 2, and 0.75H2≥H1≥0.55H2.

[0046] As a preferred embodiment of the present application, Figure 1 As shown, the drainage tube 4 has a first opening 41 at the top and a second opening 42 at the bottom. The projections of the first opening 41 and the second opening 42 on the horizontal plane are both circular, and the area ratio of the first opening 41 to the second opening 42 is 1.2-1.4. Such arrangement, on the one hand, allows the thiourea solution to circulate along the path of the inner reaction chamber 21, the first opening 41, the outer reaction chamber 22, and the second opening 42 in the thiourea crystallization chamber 2, reducing the probability of liquid convection impact during the flow of the thiourea solution, thereby reducing the occurrence of turbulence caused by the convection impact of the thiourea solution, and further improving the uniformity of thiourea crystallization; on the other hand, the ratio of the area of ​​the first opening 41 to the second opening 42 is 1.2-1.4, further increasing the amount of thiourea crystals gathered in the upper part of the thiourea crystallization chamber 2, thereby further reducing the accumulation of thiourea crystals at the bottom of the thiourea crystallization chamber 2, which helps to improve the uniformity of crystallization of the thiourea solution. This embodiment does not limit the ratio of the area of ​​the first opening 41 to the second opening 42. In another embodiment, the first opening 41 and the second opening 42 can be set to be equal in area.

[0047] As a preferred embodiment of this implementation, Figure 1 As shown, the drainage tube 4 is provided with a first arc-shaped guide portion 5 with a notch toward the outer reaction chamber 22 at the first opening 41 and the second opening 42, respectively. On the one hand, when the thiourea solution flows from the inner reaction chamber 21 to the outer reaction chamber 22, the thiourea solution near the drainage tube 4 slowly changes its flow direction under the action of the first arc-shaped guide portion 5, so that the thiourea solution gradually moves in the direction toward the outer reaction chamber 22, so that after entering the outer reaction chamber 22, it diffuses more evenly into the outer reaction chamber 22, reduces the flow velocity of the thiourea solution at the connection point between the inner reaction chamber 21 and the outer reaction chamber 22 due to the change of the movement direction, so as to maintain the uniformity of the circulation of the thiourea solution, which is conducive to improving the crystal uniformity and particle size consistency of the thiourea crystals precipitated by the thiourea.

[0048] This embodiment does not limit the structural form of the kettle body 1 and the structural form of the first arc-shaped guide portion 5, and they can adopt any one of the following examples:

[0049] Example 1: A third arc-shaped guide portion 7 concave toward the outer reaction chamber 22 is provided on the top of the kettle body 1 , and a tangent line of any point on the first arc-shaped guide portion 5 passes through the third arc-shaped guide portion 7 .

[0050] Example 2: A fourth arc-shaped guide portion 8 concave toward the outer reaction chamber 22 is provided at the bottom of the kettle body 1 , and a tangent line of any point on the second arc-shaped guide portion 5 passes through the fourth arc-shaped guide portion 8 .

[0051] Example 3: Figure 1 As shown, the top and bottom of the kettle body 1 are respectively provided with a third arc-shaped guide portion 7 and a fourth arc-shaped guide portion 8 which are concave toward the outer reaction chamber 22, and the tangent line of any point on the first arc-shaped guide portion 5 passes through the third arc-shaped guide portion 7, and the tangent line of any point on the second arc-shaped guide portion 5 passes through the fourth arc-shaped guide portion 8.

[0052] In this example, if Figure 1As shown, the drainage direction of the drainage component is from bottom to top. Under the action of the drainage component, the thiourea solution moves upward in the inner reaction chamber 21, enters the outer reaction chamber 22 at the upper part of the thiourea crystallization chamber 2, and then moves downward and enters the inner reaction chamber 21 again from the lower part of the thiourea crystallization chamber 2, thereby forming a cycle. Since the thiourea solution will change its flow direction during the flow from the inner reaction chamber 21 to the outer reaction chamber 22 and from the outer reaction chamber 22 to the inner reaction chamber 21, if the thiourea solution after the flow direction change directly hits the wall of the drainage tube 4 or the inner wall of the kettle body 1, it will cause the thiourea solution to collapse and transform into multiple streams of fluid. The multiple streams of fluid collide with each other and disrupt the uniformity of the flow of the thiourea solution, so that the flow rate of this part of the thiourea solution is different from that of the rest of the thiourea solution, and even turbulence is stimulated inside the thiourea solution, resulting in differences in particle size and uniformity of the precipitated thiourea crystals; and any one of the first arc-shaped guide portions 5 is directly connected to the drainage tube 4 or the inner wall of the kettle body 1. The tangents of any point on the first arc-shaped guide portion 5 all pass through the third arc-shaped guide portion 7. Under the guidance of the first arc-shaped guide portion 5, the flow direction of the thiourea solution is changed from a straight line to a curve. Part of the thiourea solution will move along the first arc-shaped guide portion 5 until it escapes from the drainage tube 4, and part of the thiourea solution will escape from the first arc-shaped guide portion 5 and continue to move along the tangent direction. Since the tangents of any point on the first arc-shaped guide portion 5 all pass through the third arc-shaped guide portion 7, the thiourea solution that escapes from any point on the first arc-shaped guide portion 5 can move along the tangent direction to the third arc-shaped guide portion 7, and change its movement direction under the guidance of the third arc-shaped guide portion 7, and be guided forward, avoiding The thiourea solution directly impacts the wall of the drainage tube 4 or the inner wall of the kettle body 1 after the flow direction changes, thereby avoiding the liquid collapse of the thiourea solution and the drastic changes in the flow direction and flow rate caused by the violent impact, which is helpful to improve the uniformity of the circulation of the thiourea solution and provide a guarantee for the uniformity of the thiourea crystal particle size; similarly, the second arc-shaped guide portion 5 is set so that the tangent of any point on it passes through the fourth arc-shaped guide portion 8. When part of the thiourea solution moves along the outer wall of the drainage tube 4, the flow direction will be changed from a straight line to a curve under the guidance of the second arc-shaped guide portion 5, and part of the thiourea solution will break away from the second arc-shaped guide portion 5 and continue to move along the tangent direction Movement, and since the tangent of any point on the second arc-shaped guide portion 5 passes through the fourth arc-shaped guide portion 8, the thiourea solution that escapes from any point on the second arc-shaped guide portion 5 can move to the fourth arc-shaped guide portion 8 along the tangent direction, change its movement direction under the guidance of the fourth arc-shaped guide portion 8, and be guided forward, avoiding the thiourea solution from directly impacting the wall of the drainage tube 4 or the inner wall of the kettle body 1 after the flow direction is changed, thereby avoiding the liquid collapse of the thiourea solution caused by violent impact and the drastic change of flow direction and flow velocity, which is helpful to improve the uniformity of the circulation of the thiourea solution and provide guarantee for the uniformity of the thiourea crystal particle size.

[0053] As a preferred embodiment of the present application, Figure 1 As shown, the temperature control unit 3 includes a plurality of temperature control rods 31 arranged at intervals in the outer reaction chamber 22 and extending in the vertical direction, and at least part of the projections of the plurality of temperature control rods 31 on the horizontal plane fall on the circumference of the same circle. By setting a plurality of temperature control rods 31, on the one hand, the uniformity of the temperature control of the thiourea solution by the temperature control unit 3 can be increased, and the unbalanced precipitation of the thiourea crystals caused by the uneven temperature control of the thiourea solution can be avoided, which helps to improve the crystallization efficiency while ensuring the uniformity of the particle size of the thiourea crystals; and setting the temperature control rods 31 so that at least part of the projections on the horizontal plane fall on the circumference of the same circle further improves the uniformity of the arrangement of the temperature control rods 31 in the outer reaction chamber 22, thereby further improving the uniformity of the precipitation of the thiourea crystals.

[0054] As a preferred embodiment of this implementation, Figure 1 As shown, the distance between any two adjacent temperature regulating rods 31 projected on the circumference of the same circle is equal. This arrangement further improves the uniformity of the distribution of the temperature regulating rods 31 in the outer reaction chamber 22, thereby further improving the consistency of the temperature change of the thiourea solution and the uniformity of the thiourea crystal precipitation.

[0055] As another preferred embodiment of this embodiment, Figure 1 As shown, the temperature control unit 3 also includes an upper temperature regulating ring 32 located at the top of the temperature regulating rod 31 and a lower temperature regulating ring 33 located at the bottom of the temperature regulating rod 31, and the projections of the upper temperature regulating ring 32 and the lower temperature regulating ring 33 on the horizontal plane overlap. By setting the upper temperature regulating ring 32 and the lower temperature regulating ring 33, the consistency of the temperature change at the top and bottom of the thiourea crystallization chamber 2 is improved, and setting the upper temperature regulating ring 32 and the lower temperature regulating ring 33 so that their projections on the horizontal plane overlap, it is helpful to improve the balance of the temperature change at the top and bottom of the thiourea crystallization chamber 2.

[0056] As a preferred embodiment of the present application, Figure 1 As shown, the drainage assembly includes a driving motor arranged at the bottom of the kettle body 1 and a rotating column 9 connected to the driving motor, the driving motor can drive the rotating column 9 to rotate, and at least one drainage blade 10 is installed on the rotating column 9, and the blade extension direction of the drainage blade 10 is perpendicular to the axial direction of the drainage tube 4.

[0057] Preferably, if Figure 1 As shown, there are multiple drainage blades 10, and the angles between two adjacent drainage blades 10 are equal. Specifically, multiple drainage blades 10 are installed on the same rotating column 9, and each drainage blade 10 is located in the same horizontal plane.

[0058] Anything not described in this application can be achieved by adopting or drawing on existing technologies.

[0059] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0060] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A thiourea crystallization kettle, comprising a kettle body, wherein the interior of the kettle body is hollow to form a thiourea crystallization cavity, wherein a temperature control unit capable of adjusting the temperature is provided in the thiourea crystallization cavity, wherein: The invention also includes a drainage structure arranged in the thiourea crystallization chamber, wherein the drainage structure includes an annular drainage tube, wherein the drainage tube divides the thiourea crystallization chamber into an inner reaction chamber and an outer reaction chamber which are interconnected, wherein a drainage component is arranged in the inner reaction chamber, wherein the drainage component can drive the thiourea solution to circulate between the inner reaction chamber and the outer reaction chamber, and wherein the ratio of the vertical height of the drainage tube to the vertical height of the thiourea crystallization chamber is not less than 50%.

2. The thiourea crystallization kettle according to claim 1, characterized in that The ratio of the vertical height of the drainage tube to the vertical height of the thiourea crystallization chamber is 55%-75%.

3. The thiourea crystallization kettle according to claim 1, characterized in that The drainage tube has a first opening at the top and a second opening at the bottom. The projections of the first opening and the second opening on the horizontal plane are both circular. The area ratio of the first opening to the second opening is 1.2-1.

4.

4. The thiourea crystallization kettle according to claim 3, characterized in that The guide tube is provided with a first arc-shaped guide portion and a second arc-shaped guide portion at the first opening and the second opening, respectively, which are notched toward the outer reaction chamber.

5. The thiourea crystallization kettle according to claim 4, characterized in that: The top and bottom of the kettle body are respectively provided with a third arc-shaped guide portion and a fourth arc-shaped guide portion which are concave toward the outer reaction chamber, and the tangent line of any point on the first arc-shaped guide portion passes through the third arc-shaped guide portion, and / or the tangent line of any point on the second arc-shaped guide portion passes through the fourth arc-shaped guide portion.

6. The thiourea crystallization kettle according to claim 1, characterized in that: The temperature control unit comprises a plurality of temperature regulating rods which are arranged at intervals in the outer reaction chamber and extend in a vertical direction, and projections of at least some of the plurality of temperature regulating rods on a horizontal plane fall on the circumference of the same circle.

7. The thiourea crystallization kettle according to claim 6, characterized in that: The distances between any two adjacent temperature regulating rods whose projections fall on the circumference of the same circle are equal.

8. The thiourea crystallization kettle according to claim 6, characterized in that: The temperature control unit further includes an upper temperature regulating ring located at the top of the temperature regulating rod and a lower temperature regulating ring located at the bottom of the temperature regulating rod, and the projections of the upper temperature regulating ring and the lower temperature regulating ring on the horizontal plane overlap.

9. The thiourea crystallization kettle according to claim 1, characterized in that: The drainage component includes a driving motor arranged at the bottom of the kettle body and a rotating column connected to the driving motor, the driving motor can drive the rotating column to rotate, and at least one drainage fan blade is installed on the rotating column, and the blade extension direction of the drainage fan blade is perpendicular to the axial direction of the drainage tube.

10. The thiourea crystallization kettle according to claim 9, characterized in that: The number of the drainage blades is multiple, and the angles between two adjacent drainage blades are equal.

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