Glycine alcohol precipitation mother liquor treatment system

Abstract

The utility model belongs to the technical field of glycine production processes, and particularly relates to a glycine alcohol precipitation mother liquor treatment system. Comprising a cooling crystallization kettle, a jacket is arranged outside the cooling crystallization kettle, the jacket is connected with a first cooling system and a second cooling system, the second cooling system comprises a liquid chlorine gasification pool, and cooling liquid is contained in the liquid chlorine gasification pool. The second cooling system is additionally arranged, after the first cooling system is used for cooling, the second cooling system is used for further cooling, and the problem that the ammonium chloride precipitation rate is insufficient due to the fact that the cooling capacity of the first cooling system is insufficient when the first cooling system is used is avoided. And the dual purposes of saving energy, reducing consumption and improving productivity are achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of glycine production process, and specifically relates to a glycine alcohol precipitation mother liquor processing system. Background Art

[0002] Glycine, also known as aminoacetic acid, is the simplest amino acid in the natural α-amino acids and is used in the fields of pesticide glyphosate, feed additives, food additives and nutritional products. The traditional chloroacetic acid ammonolysis method is generally used for the preparation of glycine, that is, chloroacetic acid and ammonia react under alcohol precipitation conditions with urotropine as a catalyst to generate glycine. The mother liquor of glycine is a methanol-water solution containing ammonium chloride, and ammonium chloride can be recovered as a by-product.

[0003] The processing flow of the mother liquor in the prior art is usually as follows: methanol-water solution containing ammonium chloride is distilled to recover methanol, the liquid after distillation is evaporated and concentrated, the concentrated liquid is cooled and crystallized, and the residue containing crystalline solid and liquid is centrifuged for solid-liquid separation to obtain the finished ammonium chloride product. For example, the prior art CN103303942B discloses a method and equipment for recovering ammonium chloride from glycine mother liquor, specifically, the glycine mother liquor containing ammonium chloride is concentrated by two-effect evaporation, and then separated by continuous crystallization to obtain ammonium chloride. The specific steps are as follows: the mother liquor of glycine is preliminarily evaporated and concentrated by vacuum in the first-effect evaporator; it is further evaporated and concentrated in the second-effect evaporator; finally, it is sent to the flash evaporator, flash-evaporated and concentrated under vacuum to make the concentration reach 45±3%; the flash concentrated liquid is sent to the continuous crystallizer for cyclic heat exchange cooling and crystallization; the ammonium chloride product is obtained by thickening and centrifugal separation. The whole process has the characteristics of small steam consumption, fast evaporation speed, and high efficiency and energy saving.

[0004] The process of circulating heat exchange cooling crystallization usually uses circulating water for cooling. The temperature of cooling crystallization will affect the precipitation rate of ammonium chloride and the production capacity of this section. Insufficient cooling capacity of circulating water will easily lead to a serious reduction in the recovery rate of ammonium chloride. If circulating water is continued to be used for cooling, the processing time of the section will be increased, the production capacity will be further reduced, and the increase of secondary crystals in the filtrate will also increase the burden of environmental protection treatment costs. Utility Model Content

[0005] In order to solve the technical problem of insufficient cooling temperature in the process of treating glycine mother liquor in the prior art, the utility model provides a glycine alcoholization mother liquor treatment system.

[0006] To achieve the above purpose, the technical solution of the utility model is as follows:

[0007] A glycine alcohol precipitation mother liquor processing system comprises a cooling crystallization kettle, wherein a jacket is arranged outside the cooling crystallization kettle, the jacket is connected to a first cooling system and a second cooling system, the second cooling system comprises a liquid chlorine gasification tank, and the liquid chlorine gasification tank contains a coolant.

[0008] Furthermore, a heat exchange pipe is arranged in the liquid chlorine gasification pool, the inlet and outlet of the heat exchange pipe are both located only outside the liquid chlorine gasification pool, and liquid chlorine is introduced into the heat exchange pipe.

[0009] Furthermore, the coolant in the liquid chlorine gasification pool is salt water.

[0010] Furthermore, the second cooling system also includes a delivery pipeline and a return pipeline. The liquid chlorine gasification tank is connected to the jacket through the delivery pipeline, and the coolant is delivered into the jacket through the delivery pipeline; the jacket is connected to the liquid chlorine gasification tank through a return pipeline, and the coolant is delivered to the liquid chlorine gasification tank through the return pipeline after heat exchange.

[0011] Furthermore, the delivery pipeline is connected to the bottom of the jacket, and the return pipeline is connected to the top of the jacket.

[0012] Furthermore, the second cooling system further includes a first delivery pump, and the first delivery pump is arranged on the delivery pipeline.

[0013] Furthermore, a discharge port is arranged at the bottom of the cooling crystallization kettle, the discharge port is connected to a discharge main pipe, and the discharge main pipe is connected to a centrifuge.

[0014] Furthermore, the number of the material discharge main pipes is 1, or the number of the material discharge main pipes is more than 2.

[0015] Furthermore, when the number of the material discharge main pipe is one, a second delivery pump is arranged on the material discharge main pipe; when the number of the material discharge main pipe is two or more, all the material discharge main pipes are connected to the second delivery pump, and the second delivery pump is connected to the centrifuge.

[0016] Furthermore, the centrifuge is a continuous feed horizontal centrifuge.

[0017] Furthermore, the centrifuge is connected to an auger conveyor.

[0018] Furthermore, the auger conveyor has a feed port, the feed port is connected to a feed pipe, a closed collecting bin is arranged on the feed pipe, and the closed collecting bin is connected to the centrifuge.

[0019] Furthermore, a mesh screen is arranged inside the closed collection bin, a vibration module is arranged on a side wall of the closed collection bin, and the vibration module is connected to the mesh screen.

[0020] Furthermore, a material level controller is also arranged in the closed collecting bin.

[0021] Furthermore, the auger conveyor is connected to a weighing module.

[0022] Furthermore, an audible and visual alarm is provided on the weighing module.

[0023] Compared with the prior art, the utility model has the following beneficial effects:

[0024] The glycine alcohol precipitation mother liquor treatment system provided by the utility model is based on the existing technology, and a second cooling system is added. After cooling by the first cooling system, the second cooling system is used to further cool down, so as to avoid the problem of insufficient ammonium chloride precipitation rate caused by insufficient cooling capacity of the first cooling system. In addition, the second cooling system of the utility model utilizes liquid chlorine and coolant for heat exchange, and indirectly utilizes the cold capacity of liquid chlorine for secondary cooling. The cold capacity of liquid chlorine is the waste cold capacity of the energy system in the plant area, so as to avoid the need for additional refrigeration units to provide cold capacity during the cooling crystallization process, and break the limitation that the production capacity is overly dependent on the circulating water temperature and cooling time of the first cooling system, so as to achieve the dual purpose of energy saving and consumption reduction and increasing production capacity.

[0025] The utility model sets a closed collection bin at the feed port of the auger conveyor to avoid the disadvantages of waste discharge, realize closed feeding, and also avoid the problems of high labor intensity of workers caused by traditional open-air / semi-open-air forklift material transfer and packaging. In addition, the utility model adopts a continuous feeding horizontal centrifuge to realize continuous closed material transfer, reducing the work intensity and process time of centrifugal operation.

[0026] The bottom of the cooling crystallization kettle of the utility model is connected to a material discharge main pipe, and a plurality of material discharge main pipes are arranged to avoid blockage of the material discharge main pipe. In addition, a second delivery pump is arranged between the material discharge main pipe and the centrifuge, and the material is forcibly delivered by the second delivery pump, thereby shortening the time of traditional material transfer relying on material gravity and reducing problems such as pipeline blockage caused by lowering of material temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of a glycine alcohol precipitation mother liquor treatment system provided by the utility model.

[0028] Description of reference numerals:

[0029] 1. Cooling crystallization kettle, 2. Jacket, 3. Liquid chlorine gasification tank, 4. Heat exchange pipeline, 5. Delivery pipeline, 6. Return pipeline, 7. First delivery pump, 8. Unloading main pipe, 9. Centrifuge, 10. Second delivery pump, 11. Auger conveyor, 12. Feed pipe, 13. Closed collection bin, 14. Screen, 15. Vibration module, 16. Weighing module. DETAILED DESCRIPTION

[0030] The technical solution of the utility model will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the utility model. All other embodiments obtained by ordinary technicians in this field without making creative work are within the protection scope of the utility model.

[0031] It should be noted that, unless otherwise specifically stated, the relative arrangements and numerical expressions of the components and steps described in these embodiments should not be construed as limiting the scope of the present invention.

[0032] The following description of the exemplary embodiments is merely illustrative and does not in any sense limit the present invention and its application or use. The techniques, methods and devices known to ordinary technicians in the relevant fields may not be discussed in detail here, but in the case of applying these techniques, methods and devices, these techniques, methods and devices should be regarded as part of this specification.

[0033] The utility model provides a glycine alcohol precipitation mother liquor processing system, such as Figure 1 As shown, it includes a cooling crystallization kettle 1, a jacket 2 is arranged outside the cooling crystallization kettle 1, and the jacket 2 is connected to a first cooling system and a second cooling system. The first cooling system uses conventional circulating water for cooling; the connection port of the first cooling system and the jacket 2 and the connection port of the jacket 2 and the second cooling system can be shared or different connection ports can be used. The second cooling system includes a liquid chlorine gasification pool 3, and the liquid chlorine gasification pool 3 contains a coolant.

[0034] After the material after evaporation and concentration of the kettle residue is placed in the cooling crystallization kettle 1, it is first cooled by circulating water using the first cooling system. After cooling, the circulating water in the jacket 2 is drained, and then secondary cooling is performed using the second cooling system; the material in the cooling crystallization kettle is cooled to about room temperature, and the mixture of crystallized material and liquid enters the next process.

[0035] A heat exchange pipe 4 is arranged in the liquid chlorine gasification pool 3, and the inlet and outlet of the heat exchange pipe 4 are only arranged outside the liquid chlorine gasification pool 3. Liquid chlorine is introduced into the heat exchange pipe 4, and the coolant in the liquid chlorine gasification pool 3 is brine. After the liquid chlorine passes through the heat exchange pipe 4 inside the liquid chlorine gasification pool 3, the temperature of the liquid chlorine is lower than that of the brine. Therefore, the liquid chlorine and the brine exchange heat, the liquid chlorine absorbs heat to become chlorine gas, and the brine releases heat to become low-temperature brine. The low-temperature brine is transported to the jacket 2 to cool the material in the cooling crystallization kettle 1. In order to increase the contact area between the liquid chlorine and the brine, the heat exchange pipe 4 is set in an S-shaped bend in the liquid chlorine gasification pool.

[0036] The second cooling system also includes a delivery pipe 5 and a return pipe 6. The liquid chlorine gasification pool 3 is connected to the jacket 2 through the delivery pipe 5, and the coolant is delivered into the jacket 2 through the delivery pipe 5; the jacket 5 is connected to the liquid chlorine gasification pool 3 through the return pipe 6, and the coolant is delivered to the liquid chlorine gasification pool 3 through the return pipe 6 after heat exchange, thereby realizing circulating cooling.

[0037] In order to increase the cooling efficiency and avoid the influence of gravity on the coolant, the delivery pipe 5 is connected to the bottom of the jacket 2 , and the return pipe 6 is connected to the top of the jacket 2 .

[0038] The second cooling system also includes a first delivery pump 7, which is arranged on the delivery pipeline 5. The first delivery pump 7 can increase the delivery efficiency of the coolant and can also control the delivery amount of the coolant. In addition, a temperature sensor is arranged inside the cooling crystallization kettle 1, and the temperature sensor is used to detect the temperature inside the cooling crystallization kettle 1. The power or speed of the first delivery pump 7 can be adjusted using the temperature data collected by the temperature sensor, thereby controlling the crystallization cooling rate. When the temperature of the material in the cooling crystallization kettle 1 drops to 25°C, keep it warm for 30 minutes, and then send the material to the next process.

[0039] A discharge port is arranged at the bottom of the cooling crystallization kettle 1, and the discharge port is connected to a discharge pipe 8, and the discharge pipe 8 is connected to a centrifuge 9. The cooled material is sent into the centrifuge 9 through the discharge pipe 8 for solid-liquid separation. Among them, the number of the discharge pipes 8 is 1, or the number of the discharge pipes 8 is 2 or more. When the number of the discharge pipes 8 is 1, a second delivery pump 10 is arranged on the discharge pipe 8, and at the same time, a discharge pipe 8 with a larger diameter can be used to avoid material blockage; when the number of the discharge pipes 8 is 2 or more, all the discharge pipes 8 are connected to the second delivery pump 10, and the second delivery pump 10 is connected to the centrifuge 9. The second delivery pump 10 provides power for the transportation of materials, improves the material transmission speed, and also avoids the risk of material blockage.

[0040] The centrifuge 9 is a horizontal centrifuge with continuous feeding, which realizes continuous material transfer and reduces the working time of centrifugal operation. The centrifuge 9 is connected to the auger conveyor 11, which is arranged below the centrifuge 9; after the material is separated into solid and liquid by the centrifuge 9, the solid material is sent to the auger conveyor 11, and the liquid material is discharged through other pipelines for treatment.

[0041] The auger conveyor 11 has a feed port, which is connected to a feed pipe 12. A closed collection bin 13 is provided on the feed pipe 12, and the closed collection bin 13 is connected to the centrifuge 9. A mesh screen 14 is provided inside the closed collection bin 13, and the mesh screen 14 is arranged horizontally to receive solid materials falling from above. A vibration module 15 is provided on the side wall of the closed collection bin 13, and the vibration module 15 is connected to the mesh screen 14. The vibration module 15 causes the mesh screen 14 to vibrate, and then the material on the mesh screen 14 falls into the auger conveyor 11 below, ensuring that the bin does not accumulate, block, or overflow. The connection between the vibration module 15 and the mesh screen 14 and the vibration principle thereof belong to the prior art and will not be further described here.

[0042] A material level controller is also provided in the closed collection bin 13, and the material level controller is used to detect the material height in the closed collection bin 13 to avoid material accumulation; the material level controller may be a material level sensor. In order to clean the closed collection bin 13 and the auger conveyor 11, the auger conveyor 11 may also be connected to a backwashing jet pipe, and the backwashing jet pipe is connected to the tail of the auger conveyor 11. When cleaning is required, tap water is sprayed through the backwashing jet pipe to clean the auger conveyor 11, and at the same time, the closed collection bin 13 can also be preliminarily cleaned.

[0043] The auger conveyor 11 is connected to the weighing module 16. After passing through the auger conveyor 11, the solid material reaches the weighing module 16 for weighing and packaging to obtain the finished ammonium chloride. The weighing module 16 is provided with an audible and visual alarm. When the material on the weighing module 16 reaches the upper weight limit, the audible and visual alarm gives an alarm prompt to avoid the finished product overflowing and causing material leakage.

[0044] A valve is provided at the discharge port of the cooling crystallization kettle 1; the first delivery pump 7, the temperature sensor, the valve provided at the discharge port of the cooling crystallization kettle 1, the second delivery pump 10, the centrifuge 9, the auger conveyor 11, the material level controller, the weighing module 16, and the sound and light alarm are all electrically connected to the DCS controller. The above electrical connection methods are all existing technologies and will not be repeated here.

[0045] The first delivery pump 7 delivers low-temperature brine to the jacket 2 of the cooling crystallization kettle 1 to cool the material in the cooling crystallization kettle 1. The speed of the first delivery pump 7 and the temperature in the cooling crystallization kettle 1 are controlled by the DCS interlock to control the crystallization cooling rate; when the temperature of the material in the cooling crystallization kettle 1 drops to 25°C, keep it warm for 30 minutes; open the lower discharge port of the cooling crystallization kettle 1, the second delivery pump 10, the centrifuge 9 and the auger conveyor 11, and control the speed of the second delivery pump 10, the centrifugal time of the centrifuge 9, the speed of the auger conveyor 11 and the material level control through the DCS interlock. The controller is interlocked with the weighing module 16. When the material level controller detects that the material level is higher than the set value, the frequency of the second delivery pump 10 is automatically reduced, and the material inlet and outlet of the centrifuge 9 are reduced. When the material level is reduced, the frequency of the second delivery pump 10 is automatically restored, and ammonium chloride is continuously produced under automatic control and discharged into ton bags. When the weight displayed on the weighing module 16 is 950kg, the sound and light alarm will sound on site, the speed of the second delivery pump 10 will be reduced, the time of the centrifuge 9 will be extended, and the auger conveyor 11 will be closed. After replacing the new ton bag, normal operation will be restored. Manual stop and recovery buttons are set on site.

[0046] The above specific implementation methods are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model is described in detail with reference to examples, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A glycine alcohol precipitation mother liquor treatment system, comprising a cooling crystallization kettle, characterized in that: A jacket is arranged outside the cooling crystallization kettle, and the jacket is connected to a first cooling system and a second cooling system. The second cooling system comprises a liquid chlorine gasification pool, and the liquid chlorine gasification pool contains a coolant.

2. The glycine alcoholation mother liquor treatment system according to claim 1, characterized in that: A heat exchange pipe is arranged in the liquid chlorine gasification pool, the inlet and outlet of the heat exchange pipe are both arranged only outside the liquid chlorine gasification pool, and liquid chlorine is introduced into the heat exchange pipe; the coolant in the liquid chlorine gasification pool is salt water.

3. The glycine alcoholation mother liquor treatment system according to claim 1, characterized in that: The second cooling system further comprises a delivery pipeline and a return pipeline, wherein the liquid chlorine gasification pool is connected to the jacket via the delivery pipeline, and the coolant is delivered into the jacket via the delivery pipeline; the jacket is connected to the liquid chlorine gasification pool via the return pipeline, and the coolant is delivered to the liquid chlorine gasification pool via the return pipeline after heat exchange; The delivery pipeline is connected to the bottom of the jacket, and the return pipeline is connected to the top of the jacket.

4. The glycine alcoholation mother liquor treatment system according to claim 3, characterized in that: The second cooling system further includes a first delivery pump, which is disposed on the delivery pipeline.

5. The glycine alcoholation mother liquor treatment system according to claim 1, characterized in that: A discharge port is arranged at the bottom of the cooling crystallization kettle, and the discharge port is connected to a discharge main pipe, and the discharge main pipe is connected to a centrifuge.

6. The glycine alcoholation mother liquor treatment system according to claim 5, characterized in that: The number of the material discharge main pipes is 1, or the number of the material discharge main pipes is 2 or more; When the number of the material discharge main pipe is one, a second delivery pump is arranged on the material discharge main pipe; when the number of the material discharge main pipe is two or more, all the material discharge main pipes are connected to the second delivery pump, and the second delivery pump is connected to the centrifuge.

7. The glycine alcoholation mother liquor treatment system according to claim 5 or 6, characterized in that: The centrifuge is a continuous feed horizontal centrifuge.

8. The glycine alcoholation mother liquor treatment system according to claim 5 or 6, characterized in that: The centrifuge is connected to the auger conveyor; The auger conveyor has a feed port, which is connected to a feed pipe. A closed collecting bin is arranged on the feed pipe, and the closed collecting bin is connected to the centrifuge.

9. The glycine alcoholization mother liquor treatment system according to claim 8, characterized in that: A mesh screen is arranged inside the closed collection bin, a vibration module is arranged on the side wall of the closed collection bin, and the vibration module is connected to the mesh screen.

10. The glycine alcoholation mother liquor treatment system according to claim 8, characterized in that: The auger conveyor is connected to a weighing module, and an audible and visual alarm is arranged on the weighing module.

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