WO2020088294A1

WO2020088294A1 - Device for evaporation and crystallization

Info

Publication number: WO2020088294A1
Application number: PCT/CN2019/112400
Authority: WO
Inventors: 陈志荣; 刘金龙; 邱贵生; 王志轩; 马啸; 周有桂; 陈卫勇; 刘晓庆
Original assignee: 浙江新和成股份有限公司; 浙江大学; 山东新和成氨基酸有限公司; 山东新和成精化科技有限公司; 山东新和成药业有限公司
Priority date: 2018-10-31
Filing date: 2019-10-22
Publication date: 2020-05-07
Also published as: DE112019001119T5

Abstract

Provided by the present invention is a device used for evaporation and crystallization. The device comprises an evaporation container and a crystallization container. The device used for evaporation and crystallization further comprises a first circulation unit and a second circulation unit. The first circulation unit comprises a first branch pipe, a first circulation pump, and a first circulation inlet pipe that are successively connected. The second circulation unit comprises a second branch pipe, a second circulation pump, a heater, and a second circulation inlet pipe that are successively connected. The first circulation inlet pipe and the second circulation inlet pipe are connected to the evaporation container. By means of providing an additional first circulation loop, a portion of fine crystals are reintroduced into the crystallization container as a crystal nucleus, and a product that has more uniform particles and a controllable particle size is finally obtained.

Description

Device for evaporation and crystallization

Related application

This application requires the application on October 31, 2018, the application number is 201811291575.8, the name is "device for evaporative crystallization" and the application on October 31, 2018, the application number is 201821784240.5, the name is "for evaporative crystallization The priority of the Chinese patent application of "device" is hereby incorporated by reference in its entirety.

Technical field

The invention relates to the field of chemical equipment, in particular to a device for evaporation and crystallization.

Background technique

In the continuous crystallization process, the method of evaporating solvent crystallization is often used. The corresponding device generally includes an evaporation container, a crystallization container and a circulation circuit. The device is difficult to effectively control the particle size of the crystal, resulting in uneven distribution of crystal size, poor crystal regularity, and low crystal purity, which affects the quality of the product . In addition, the crystallization efficiency of the device is relatively low.

Summary of the invention

In view of the above problems, the present invention provides a device for evaporative crystallization with high crystallization efficiency.

The present invention provides an apparatus for evaporative crystallization, which includes:

An evaporation container, the evaporation container is used to evaporate the solvent, a guide tube is provided at the bottom of the evaporation container, and an evaporation gas outlet is also provided at the top of the evaporation container;

A crystallization container, the crystallization container is used for crystallization, the crystallization container is located below the evaporation container, the guide tube extends into the crystallization container, and communicates with the crystallization container, the bottom of the crystallization container is provided There is a crystal slurry outlet; wherein, the side wall of the crystallization container is connected with a circulating material outlet pipe, and the circulating material outlet pipe is branched into a first branch pipe and a second branch pipe;

The device for evaporating and crystallization further includes a first circulation unit and a second circulation unit. The first circulation unit includes the first branch pipe, the first circulation pump, the first circulation inlet pipe, and the first branch pipe The first circulation pump is connected; the first circulation inlet pipe has a first end and a second end, the first end of the first circulation inlet pipe is connected to the first circulation pump, the first circulation inlet pipe The second end of the is connected to the evaporation container;

The second circulation unit includes the second branch pipe, a second circulation pump, a heater, and a second circulation inlet pipe. The second branch pipe is connected to the second circulation pump and the heater in sequence, and the second circulation inlet The tube has a third end and a fourth end, the third end of the second circulation inlet tube is connected to the heater, and the fourth end of the second circulation inlet tube is connected to the evaporation container;

The device for evaporating and crystallization further includes a raw material liquid inlet pipe connected to the second branch pipe and used for pumping the raw material liquid to the heater through the second circulation.

The crystallization vessel is also provided with a rectifier classifier. The rectifier classifier includes a plurality of channels, and the ratio of the size of the lower end of the channel to the size of the upper end of the channel is 1.1: 1 to 10: 1.

The size of the upper end of the channel is 3 mm to 100 mm.

The opening rate of the channel is 5% -50%.

A defoamer and defoamer is provided inside the evaporation container near the evaporation gas outlet.

The side wall of the evaporation container and the side wall of the crystallization container are also provided with a balance tube, and the balance tube communicates the evaporation container and the crystallization container.

The invention also provides the application of the device for evaporative crystallization in the field of continuous crystallization.

The device for evaporative crystallization has the following advantages:

Due to multiple forces (fluid force from the evaporation container, force caused by discharge, force caused by the first circulation pump and the second circulation pump), the The crystallization liquid in the crystallization vessel is in a turbulent state, which can effectively avoid the occurrence of crystal agglomeration, making the size of the precipitated crystal particles controllable; at the same time, the turbulent state further promotes the separation of large and small crystals, and plays a role in the first circulation pump and the second circulation pump Next, the fine crystal particles in the crystal particles are circulated and introduced into the heater and the evaporation container. Part of the fine crystal particles that are circulated and introduced into the evaporation vessel can be used as crystal nuclei for the next cycle of crystallization, so that the subsequent crystal particles precipitate faster and form crystal particles of a more uniform size.

A heater is provided in the second branch pipe, which can give the heat of the raw material liquid or the second mother liquid transported by the second circulation unit, and cause it to evaporate part of the solvent in the evaporation container, which is more beneficial to the raw material liquid or the second mother liquid The crystallization vessel performs crystallization. The device can realize the continuous formation of crystalline particles, the crystallization efficiency is high, and it is suitable for industrial production.

Further, when a rectifier classifier is also provided in the crystallization vessel, the rectifier classifier can sort out the chaotic flow field distribution in the crystallization vessel (when there is no rectifier classifier), so that the length of the liquid flow process below the rectifier classifier tends In order to be consistent, the flow velocity of each stream tends to be consistent, so that the flow field distribution is regular and orderly, which promotes more uniform precipitation of crystalline particles. At the same time, there is a flow rate difference between the rectifier classifier channel and the rectifier classifier. Because the low flow rate below the rectifier classifier is unable to continuously entrain larger crystalline particles, the larger crystalline particles are in the low-flow fluid under the rectifier classifier. Precipitation occurs during entrainment, and the fine-grained particles entrained by the flow below the rectifier classifier near the channel of the rectifier classifier will be entrained by the high-velocity liquid flow in the channel of the rectifier classifier and recirculated into the heater for reheating Dissolve, and circulate into the evaporation vessel as crystal nuclei. In the whole process, by adjusting the opening ratio of the channel and the ratio of the upper and lower dimensions of the channel, the role of screening and separating crystals can be achieved, so that the final product with more uniform and controllable crystal size can be obtained.

BRIEF DESCRIPTION

FIG. 1 is a schematic structural diagram of an apparatus for evaporative crystallization according to Embodiment 1 of the present invention.

FIG. 2 is a schematic structural diagram of an apparatus for evaporative crystallization according to Embodiment 2 of the present invention.

3 is a schematic structural view of a rectifier and classifier in the device for evaporative crystallization of FIG. 2.

Among them, 1. raw material liquid inlet pipe; 2a, first branch pipe; 2b, second branch pipe; 3. second circulation pump; 4. heater; 5. second circulation inlet pipe; 6. evaporation vessel; 7. diversion Pipe; 8. Crystallization vessel; 9. Defoaming and demister; 10. Evaporation gas outlet; 11. Balance pipe; 12. Circulation material outlet pipe; 13. First circulation pump; 14. First circulation inlet pipe; 15. Crystal slurry discharge port; 16, centrifuge; 17, rectifier classifier; 18, channel.

detailed description

The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

Please refer to FIG. 1, Embodiment 1 of the present invention provides an apparatus for evaporative crystallization. The device for evaporating and crystallization includes an evaporating container 6 and a crystallization container 8. The crystallization container 8 is located below the evaporating container 6. The evaporating container 6 is used to evaporate the solvent, and the crystallization container 8 is used for crystallization. The top of the evaporating container 6 is provided with The evaporation gas outlet 10, the bottom of the evaporation container 6 is provided with a guide tube 7, the guide tube 7 extends into the crystallization container 8 and communicates with the crystallization container 8, and the side wall of the crystallization container 8 is connected with a circulating material outlet tube 12, circulating The material outlet pipe 12 branches into a first branch pipe 2a and a second branch pipe 2b.

The evaporative crystallization also includes a first circulation unit and a second circulation unit, the first circulation unit includes a first branch 2a, a first circulation pump 13, a first circulation inlet pipe 14, the first branch 2a and the first circulation The pump 13 is connected, and the first circulation inlet pipe 14 has a first end and a second end. The first end of the first circulation inlet pipe 14 is connected to the first circulation pump 13, and the second end of the first circulation inlet pipe 14 is connected to the evaporation Container 6.

The second circulation unit includes the second branch pipe 2b, the second circulation pump 3, the heater 4 and the second circulation inlet pipe 5. The second branch pipe 2b is connected to the second circulation pump 3 and the heater 4 in sequence, and the second circulation inlet The tube 5 has a third end and a fourth end. The third end of the second circulation inlet 5 is connected to the heater 4, and the fourth end of the second circulation inlet 5 is connected to the evaporation container 6.

The device for evaporating and crystallization further includes a raw material liquid inlet pipe 1, which is connected to the second branch pipe 2b, and is used to send the raw material liquid to the heater 4 through the second circulation pump 3.

There are two circulation circuits outside the crystallization vessel 8 and the evaporation vessel 6. The first circulation circuit (corresponding to the first circulation unit) is: crystallization vessel 8, circulation material outlet pipe 12, first branch pipe 2a, first circulation pump 13, first circulation inlet pipe 14, evaporation vessel 6; second circulation The circuit (corresponding to the second circulation unit) is: a crystallization vessel 8, a circulation material outlet pipe 12, a second branch pipe 2b, a second circulation pump 3, a heater 4, a second circulation inlet pipe 5, and an evaporation vessel 6. Among them, the second branch 2b is also responsible for connecting to the raw material liquid inlet pipe 1 and continuously introducing the raw material liquid into the second circulation circuit.

The first circulation circuit is used to lead part of the mother liquor (defined as the first mother liquor) in the crystallization container 8 and part of the fine crystal particles (defined as the first fine crystal) obtained by the crystallization directly to the evaporation vessel 6, the part of the fine crystals The particles can be used as crystal nuclei in the next cycle, which will induce more uniform crystal particles. It should be noted that the first fine crystals can continue to grow to obtain larger and more uniform crystalline particles. At the same time, the re-entry of the first fine crystals into the crystallization container 8 will also induce more crystalline particles to form orderly, that is, That is to say, the effect of the first circulation circuit is divided into two aspects: one is to make a larger number of crystalline particles formed; the other is to make fine-crystalline particles grow into uniform crystalline particles.

The second circulation circuit is used to pass another part of the mother liquid (defined as the second mother liquid) in the crystallization container 8 and another part of the fine crystal particles (defined as the second fine crystal) obtained by crystallization into the evaporation container 6 through the action of the heater 4 After the solvent evaporates, it enters the crystallization vessel 8 to perform the next cycle of crystallization.

The evaporation vessel 6 generally does not require additional heating. The temperature of the raw material liquid or the second mother liquid flowing from the second circulation inlet 5 after being heated by the heater 4 will increase. Therefore, the raw material liquid or the second The mother liquor evaporates part of the solvent in the evaporation container 6. In order to avoid that the foam generated during the evaporation of the solvent entrains part of the product and causes loss of yield, a defoaming and defoaming device 9 is provided near the evaporation gas outlet 10 inside the evaporation container 6, and the defoaming and defoaming device 9 can be Screen structure or other types of defoamer and demister.

The side wall of the evaporation container 6 and the side wall of the crystallization container 8 are also provided with a balance tube 11, which connects the evaporation container 6 and the crystallization container 8.

The bottom of the crystallization container 8 is provided with a crystal slurry discharge port 15.

Please refer to FIG. 2, Embodiment 2 of the present invention provides an apparatus for evaporative crystallization. The device for evaporative crystallization is basically the same in structure as the device for evaporative crystallization of Embodiment 1, except that a rectifier and classifier 17 is provided in the crystallization vessel 8. Referring to FIG. 3, the rectifier classifier 17 includes multiple channels 18. The function of the rectifier classifier 17 is to obtain more uniform crystalline particles.

The design purpose of the size of the lower end of the channel 18 is greater than the size of the upper end of the channel 18 has two aspects: (1) to prevent the phenomenon of "backmixing" of particles; (2) to avoid the possibility of the channel 18 being blocked. The axial section of the channel 18 may be, but not limited to, trapezoidal, bowl-shaped, or drop-shaped.

The ratio of the size of the lower end of the channel 18 to the size of the upper end of the channel 18 is 1.1: 1 to 10: 1. Preferably, the ratio of the size of the lower end of the channel 18 to the size of the upper end of the channel 18 It is 1.5: 1 ～ 5: 1.

The size of the upper end of the channel 18 is 3 mm to 100 mm, preferably 5 mm to 50 mm.

The aperture ratio of the plurality of channels 18 (that is, the sum of the area of the upper ends of the channels as a percentage of the area of the upper surface of the rectifier classifier) is 5% to 50%, preferably 10% to 30%.

The device for evaporative crystallization has the following advantages:

The evaporation container 6 is used to evaporate the solvent in the raw material liquid, and the crystallization container 8 is used for crystallization. By forking the circulating material outlet pipe 12 into a first branch pipe 2a and a second branch pipe 2b, the first branch pipe 2a is used to transform the raw material liquid The fine crystal particles in the crystal particles formed by the crystallization are redirected into the evaporation container 6, and the fine crystal particles can be used as crystal nuclei for the next cycle of crystallization, thereby inducing more and more uniform crystal particles to form; the second branch 2b The heater 4 is provided to give heat to the raw material liquid or the second mother liquid, and the partial evaporation of the solvent in the evaporation container 6 is more conducive to the crystallization of the raw material liquid or the second mother liquid in the crystallization container 8.

The device can be used for the continuous formation of grains. In particular, it is suitable for vitamin B6, hexonic acid, sucralose, ethyl maltol, methionine, gulonic acid, citric acid, threonine, tryptophan, sodium gluconate, glucose, glutamic acid, Evaporative crystallization of lysine or sorbitol.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To simplify the description, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered within the scope of this description.

The above-mentioned embodiments only express several embodiments of the present invention, and their descriptions are more specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that, for a person of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all fall within the protection scope of the present invention. Therefore, the protection scope of the invention patent shall be subject to the appended claims.

Claims

A device for evaporative crystallization, including:

An evaporation container (6) is used to evaporate the solvent, a guide tube (7) is provided at the bottom of the evaporation container (6), and an evaporation gas is also provided at the top of the evaporation container (6) Export (10);

A crystallization container (8), the crystallization container (8) is used for crystallization, the crystallization container (8) is located below the evaporation container (6), and the guide tube (7) extends to the crystallization container (8) 8) inside and communicate with the crystallization container (8), the bottom of the crystallization container (8) is provided with a crystal slurry discharge port (15);

A circulating material outlet pipe (12) is connected to the side wall of the crystallization container (8), and the circulating material outlet pipe (12) branches into a first branch pipe (2a) and a second branch pipe (2b);

The device for evaporative crystallization also includes a first circulation unit and a second circulation unit, the first circulation unit includes the first branch (2a), a first circulation pump (13), and a first circulation inlet ( 14), the first branch pipe (2a) is connected to the first circulation pump (13); the first circulation inlet pipe (14) has a first end and a second end, and the first circulation inlet pipe (14) ) Has a first end connected to the first circulation pump (13), and a second end of the first circulation inlet pipe (14) is connected to the evaporation vessel (6);

The second circulation unit includes the second branch pipe (2b), a second circulation pump (3), a heater (4) and a second circulation inlet pipe (5). The second branch pipe (2b) is A second circulation pump (3) and a heater (4) are connected, the second circulation inlet pipe (5) has a third end and a fourth end, and the third end of the second circulation inlet pipe (5) is connected to all The heater (4) is connected, and the fourth end of the second circulation inlet tube (5) is connected to the evaporation container (6);

The device for evaporating and crystallization further includes a raw material liquid inlet pipe (1), the raw material liquid inlet pipe (1) is connected to the second branch pipe (2b), and is used to send the raw material liquid through the second circulation pump (3) To the heater (4).
The device for evaporative crystallization according to claim 1, characterized in that a rectifying classifier (17) is further provided in the crystallization vessel (8), and the rectifying classifier (17) includes a plurality of channels (18) ), The ratio of the size of the lower end of the channel (18) to the size of the upper end of the channel (18) is 1.1: 1 to 10: 1.
The device for evaporative crystallization according to claim 2, characterized in that the size of the upper end of the channel (18) is 3 mm to 100 mm.
The device for evaporative crystallization according to claim 2, characterized in that the opening rate of the channel (18) is 5% to 50%.
The device for evaporative crystallization according to claim 1, characterized in that a defoamer and defoamer (9) is provided inside the evaporation container (6) near the evaporation gas outlet (10).
The device for evaporative crystallization according to claim 1, characterized in that a side wall of the evaporation container (6) and the side wall of the crystallization container (8) are further provided with a balance tube (11), The balance tube (11) communicates the evaporation container (6) and the crystallization container (8).
The application of the evaporative crystallization device according to any one of claims 1 to 6 in the field of continuous crystallization.