阅读说明：本技术 一种碳纤维生产中聚合液回收处理的方法和装置 (Method and device for recycling polymerization liquid in carbon fiber production ) 是由 沈传石 张立坚 赵彦国 刘运波 周占发 宋立志 齐志军 时英勇 张伟 杨昆 陈志 于 2021-10-14 设计创作，主要内容包括：本发明涉及一种碳纤维生产中聚合液回收处理的方法和装置,其解决现有技术中存在的技术问题,其设有脱单塔进料泵；第一静态混合器；脱单塔；浓缩塔；浓缩塔出料泵；第二静态混合器；聚合液产品罐；聚合液回收罐；聚合液回收泵；回收聚合液过滤器；加氨设施；所述聚合液回收罐收集不合格聚合液,通过聚合液回收泵出口管线及回收聚合液过滤器后与脱单塔进料泵出口合格聚合液混合,进入第一静态混合器,进行初步混合后,进入脱单塔、浓缩塔,除杂脱泡后由浓缩塔出料泵送出,进一步氨化后进入第二静态混合器,经检测合格聚合液送聚合液产品罐。本发明同时提供碳纤维生产中聚合液回收处理的方法。本发明可用于碳纤维生产领域。(The invention relates to a method and a device for recovering and treating polymerization liquid in carbon fiber production, which solve the technical problems in the prior art and are provided with a feeding pump of a demonomerization tower; a first static mixer; a demonomerization tower; a concentration tower; a discharge pump of the concentration tower; a second static mixer; a polymerization liquid product tank; a polymerization liquid recovery tank; a polymerization liquid recovery pump; recovering the polymerization liquid filter; an ammonia addition facility; the polymerization liquid recovery tank collects unqualified polymerization liquid, the polymerization liquid is mixed with qualified polymerization liquid at the outlet of a feeding pump of a demouding tower after passing through an outlet pipeline of the polymerization liquid recovery tank and a recovered polymerization liquid filter, the polymerization liquid enters a first static mixer, the polymerization liquid enters the demouding tower and a concentration tower after being preliminarily mixed, the polymerization liquid is conveyed out by a discharge pump of the concentration tower after impurity removal and defoaming, the polymerization liquid enters a second static mixer after being further aminated, and the qualified polymerization liquid is conveyed to a polymerization liquid product tank after detection. The invention also provides a method for recovering and treating the polymerization liquid in the carbon fiber production. The invention can be used in the field of carbon fiber production.)

1. A polymerization liquid recovery processing device in carbon fiber production is characterized in that a feeding pump of a demonomerization tower is arranged; a first static mixer; a demonomerization tower; a concentration tower; a discharge pump of the concentration tower; a second static mixer; a polymerization liquid product tank; a polymerization liquid recovery tank; a polymerization liquid recovery pump; recovering the polymerization liquid filter; an ammonia addition facility;

the polymerization liquid recovery tank collects unqualified polymerization liquid, the polymerization liquid passes through an outlet pipeline of the polymerization liquid recovery tank and a recovered polymerization liquid filter, then is mixed with qualified polymerization liquid at an outlet of a feeding pump of the demonomerization tower, enters the first static mixer, is preliminarily mixed, then enters the demonomerization tower and the concentration tower, is discharged by a discharge pump of the concentration tower after impurity removal and defoaming, enters the second static mixer after further ammoniation, and is sent to a polymerization liquid product tank after the qualified polymerization liquid is detected.

2. A polymer liquid recovery processing device according to claim 1, further comprising a feed pump variable frequency controller; a single feed removal pressure detection point; a demonomerization feeding pressure regulating valve; an online rotational viscometer; a three-way switch valve; a variable frequency controller of a polymer liquid recovery pump;

the polymerization liquid recovery pump frequency-variable controller accurately controls the recovery amount of unqualified polymerization liquid, mixes the qualified polymerization liquid of the feed pump frequency-variable controller in proportion, and is stable through pressure detection and regulating valve control system before single feeding before entering a single feeding tower, and an online rotary viscometer is configured after ammoniation to timely detect the quality of recovered polymerization liquid products and store the polymerization liquid products in a corresponding storage tank through a three-way switch valve.

3. A method for recovering and treating polymerization liquid in carbon fiber production is characterized by comprising the following steps:

(1) when key indexes of the polymerization liquid product are unqualified in inspection and analysis, sending the batch of products to a polymerization liquid recovery tank for storage; when the online polymerization liquid is qualified and stable, keeping the frequency conversion of the gear pump of the online polymerization liquid unchanged, starting a polymerization liquid recovery pump, adjusting the recovered polymerization liquid, and sending the two polymerization liquids to a first static mixer for mixing;

(2) the blended polymer liquid passing through the static mixer enters a demonomerization tower and a concentration tower;

(3) the polymerization liquid treated by the demonomerization tower and the concentration tower is sent to an ammoniation facility by a discharge pump of the concentration tower for ammoniation treatment, the ammoniation coefficient is adjusted and tracked and detected, the ammoniation coefficient in the process needs to be adjusted up on the original basis, and the ammonia neutralization degree of the blended polymerization liquid product is within the qualified index range;

(4) after being treated by an ammoniation facility, the polymerization liquid is analyzed by an online rotary viscometer, meanwhile, sampling is carried out for offline inspection, analysis and proofreading, and the qualified polymerization liquid is sent to a polymerization liquid storage tank and sent to the next procedure.

4. The method according to claim 3, wherein in the step (2), the amount of the polymer solution to be recovered should not exceed 5% by volume of the total polymer solution when the polymer solution to be recovered is passed through the demonomerization column and the concentration column again.

5. The method for recycling and treating the polymerization solution in the carbon fiber production according to claim 3, wherein in the step (1), an SH type static mixer is used for blending the polymerization solution.

6. The method for recycling the polymerization solution in the carbon fiber production according to claim 3, wherein in the step (1), when the viscosity and the solid content are simultaneously rejected, the process is carried out by a viscosity rejection process; when the situation that the viscosity and the ammonia neutralization degree are unqualified simultaneously occurs, processing by a viscosity unqualified processing method; when the solid content and the ammonia neutralization degree are unqualified at the same time, the solid content is processed by an unqualified solid content processing method; and unqualified viscosity, solid content and ammonia neutralization degree are generated at the same time, and the treatment is carried out in a viscosity unqualified treatment mode.

Technical Field

The invention relates to a method and a device for producing carbon fibers, in particular to a method and a device for recovering and treating polymerization liquid in carbon fiber production.

Background

The polymerization reaction is used as AN important component of the production of carbon fiber precursors, Acrylonitrile (AN) is used as a polymerization monomer in the production process of Polyacrylonitrile (PAN) -based carbon fibers, and dimethyl sulfoxide (DMSO) is used as a solvent. Unqualified polymerization liquid can be generated under the conditions of starting and stopping the carbon fiber precursor, adjusting the polymerization formula and sudden abnormity, and if the polymerization liquid is not recycled, the waste of the polymerization liquid is caused, and the solid waste treatment cost is increased. If the treatment is improper, the sewage treatment cost is increased for the sewage treatment device, so that the unqualified polymerization liquid is recycled in the actual production process.

At present, the recovery treatment of the polymerization liquid adopts an extraction method, namely unqualified polymerization liquid is discharged from a storage tank, a solvent in the polymerization liquid is extracted through a constant-temperature water bath, and the extracted solidified polymerization liquid is treated as solid waste. The treatment method treats the polymerization solution as waste, so that a large amount of raw materials and auxiliary materials are wasted, and the investment of extraction equipment is required to be increased.

Chinese patent application publication No. CN104178848A discloses a recovery device and method for waste spinning solution generated in a carbon fiber precursor preparation process, the device at least comprises: a waste spinning solution collecting tank, a polymerization solution defoaming kettle, a precision filter and a circulating shear pump; this useless spinning liquid collecting vat includes: the device comprises a tank body, a heat exchanger, a hot water inflow pipe, a hot water outflow pipe, a temperature controller, a nozzle, a solvent inlet pipe, a nitrogen inlet pipe, a waste spinning solution inlet, a waste spinning solution outlet, a circulating mixed solution inlet and a circulating mixed solution outlet. The recovery method comprises the following steps: collecting the waste spinning solution in a waste spinning solution collecting tank, spraying a solvent into the waste spinning solution collecting tank through a nozzle, homogenizing through a circulating shear pump, introducing nitrogen for protection, filtering through a precision filter, and defoaming through a polymerization solution defoaming kettle to obtain the spinning solution for normal spinning.

However, the apparatus mainly has the following problems: (1) the device mainly aims at the unqualified spinning solution caused by impurities, gel and bubbles, the generation condition of waste spinning solution is more complicated, and the device lacks the treatment measures of the unqualified key indexes such as viscosity, solid content and ammonia neutralization degree; (2) the device is an independent device, the equipment investment is large, and waste spinning solution is conveyed to spinning through a conveying pump after being treated by the device, so that the fluctuation of the feeding amount and the quality is easily caused.

Disclosure of Invention

The invention aims to solve the technical problems in the prior art and provides a method and a device for recovering and treating polymerization liquid in fiber production.

Therefore, the invention provides a polymerization liquid recovery processing device in carbon fiber production, which is provided with a feeding pump of a demonomerization tower; a first static mixer; a demonomerization tower; a concentration tower; a discharge pump of the concentration tower; a second static mixer; a polymerization liquid product tank; a polymerization liquid recovery tank; a polymerization liquid recovery pump; recovering the polymerization liquid filter; an ammonia addition facility; the polymerization liquid recovery tank collects unqualified polymerization liquid, the polymerization liquid passes through an outlet pipeline of the polymerization liquid recovery tank and a recovered polymerization liquid filter, then is mixed with qualified polymerization liquid at an outlet of a feeding pump of the demonomerization tower, enters the first static mixer, is preliminarily mixed, then enters the demonomerization tower and the concentration tower, is discharged by a discharge pump of the concentration tower after impurity removal and defoaming, enters the second static mixer after further ammoniation, and is sent to a polymerization liquid product tank after the qualified polymerization liquid is detected.

Preferably, the polymerization liquid recovery processing device in carbon fiber production provided by the invention is also provided with a feeding pump variable frequency controller; a single feed removal pressure detection point; a demonomerization feeding pressure regulating valve; an online rotational viscometer; a three-way switch valve; a variable frequency controller of a polymer liquid recovery pump; the polymerization liquid recovery pump frequency-variable controller accurately controls the recovery amount of unqualified polymerization liquid, mixes the qualified polymerization liquid of the feed pump frequency-variable controller in proportion, and is stable through pressure detection and regulating valve control system before single feeding before entering a single feeding tower, and an online rotary viscometer is configured after ammoniation to timely detect the quality of recovered polymerization liquid products and store the polymerization liquid products in a corresponding storage tank through a three-way switch valve.

The invention also provides a method for recovering and treating the polymerization liquid in fiber production, which comprises the following steps: (1) and when the key indexes of the polymerization liquid product are unqualified in inspection and analysis, sending the batch of products to a polymerization liquid recovery tank for storage. When the online polymerization liquid is qualified and stable, keeping the frequency conversion of the gear pump of the online polymerization liquid unchanged, starting a polymerization liquid recovery pump, adjusting the recovered polymerization liquid, conveying two strands of polymerization liquid to a first static mixer, and mixing the two strands of polymerization liquid through left and right twisted spiral sheets in a mixer channel, wherein the mixing amount of the recovered polymerization liquid accounts for 3% of the volume fraction of the total treatment amount; (2) the blended polymer solution passing through the static mixer enters a demonomerization tower and a concentration tower, the amount of polymer solution treated by the demonomerization tower and the concentration tower is slightly increased in the process, the amount of on-line polymer solution is not changed, the demonomerization and the defoaming amounts are stable, and the polymer solution after blending does not influence the technological parameters of a continuous production line; (3) the polymerization liquid treated by the demonomerization tower and the concentration tower is sent to an ammoniation facility by a discharge pump of the concentration tower for ammoniation treatment, the ammoniation coefficient is adjusted and tracked and detected, the ammoniation coefficient in the process needs to be adjusted by 2 percent on the original basis, and the neutralization degree of the ammonia in the mixed polymerization liquid product is within the qualified index range; (4) after being treated by an ammoniation facility, the polymerization liquid is analyzed by an online rotary viscometer, meanwhile, sampling is carried out for offline inspection, analysis and proofreading, and the qualified polymerization liquid is sent to a polymerization liquid storage tank and sent to the next procedure.

Preferably, in the step (1), when the recovered polymerization solution passes through the monomer removal tower and the concentration tower again, a small amount of macromolecular structures are degraded into micromolecules due to high operation temperature, so that the product quality is affected, and the amount of the recovered polymerization solution should not exceed 5% of the volume of the total polymerization solution.

Preferably, in the step (2), an SH type static mixer is adopted for mixing the polymerization liquid, and the mixer is suitable for the high-viscosity polymerization liquid medium.

Preferably, in the step (1), the recovery of the polymerization solution has unqualified solid content, and the volume fraction of the unqualified polymerization solution accounting for 4% of the total treatment amount can also meet the method.

Preferably, in the steps (1) and (3), the method can be satisfied when the neutralization degree of the recovered polymerization liquid ammonia is unqualified, and the volume fraction of the unqualified polymerization liquid blending amount accounting for 5% of the total treatment amount is also satisfied, and the ammonia adding coefficient of the process needs to be adjusted to be 3% on the original basis.

Preferably, when the situation that the viscosity and the solid content are simultaneously unqualified occurs, the treatment is carried out by a viscosity unqualified treatment method; further, when the situation that the viscosity and the ammonia neutralization degree are simultaneously unqualified occurs, the viscosity is processed by a unqualified viscosity processing method; further, when the solid content and the ammonia neutralization degree are unqualified at the same time, the solid content is processed by an unqualified solid content processing method; furthermore, unqualified viscosity, solid content and ammonia neutralization degree are simultaneously generated, and the treatment is carried out in a viscosity unqualified treatment mode.

The invention has the following beneficial effects:

according to the invention, the polymer liquid index of the product is detected, the unqualified polymer liquid is accurately subjected to proportion recovery control on line, and zero output of unqualified products is realized under the condition that the quality of the final polymer liquid product is not influenced.

Drawings

Fig. 1 is a schematic structural diagram of a recovery processing device for a polymerization liquid in a monomer recovery tower in carbon fiber precursor production according to an embodiment of the present application.

In the figure: 1. feeding a polymerization solution; 2. a demonomerization tower feed pump; 3. a feed pump variable frequency controller; 4. a stripping feed sampling point; 5. a first static mixer; 6. a first static mixer internal; 7. a single feed removal pressure detection point; 8. a demonomerization feeding pressure regulating valve; 9. a demonomerization tower; 10. a concentration tower; 11. a discharge pump of the concentration tower; 12. a second static mixer; 13. a second static mixer internal; 14. an online rotational viscometer; 15. a polymer liquid product sampling point; 16. a three-way switch valve; 17. a polymerization liquid product tank; 18. a polymerization liquid recovery tank; 19. a polymerization liquid recovery pump; 20. a variable frequency controller of a polymer liquid recovery pump; 21. recovering a polymerization solution sampling point; 22. recovering the polymerization liquid filter; 23. and (4) an ammonia adding facility.

Detailed Description

The present invention will be further described with reference to the following examples.

Example 1

As shown in the attached figure 1, the device for recovering and treating the polymerization liquid in the carbon fiber production comprises a polymerization liquid recovery pump 19, a first static mixer 5, a single-removing tower feeding pump 2, a single-removing tower 9, a concentration tower 10 and other devices, an online rotary viscometer 14, an automatic regulating valve, a DCS control system and other instruments.

And the polymerized liquid recovery pump 19, the single-tower-removing feeding pump 2 and the concentration tower discharging pump 11 adopt an inlet gear pump, the single-rotation volume of the gear pump is fixed, and during mixing, the rotating speed of the gear pump is adjusted to accurately measure and mix.

The two strands of polymerization liquid simultaneously enter a first static mixer 5, and simultaneously enter a second static mixer 12 after ammonia adding treatment, the two static mixers adopt SH type, the mixer consists of double channels, spiral sheets are placed in the channels, the positions of the double channels of adjacent units are staggered by 90 degrees, and a fluid redistribution chamber is arranged between the units, so that the two strands of polymerization liquid are fully mixed.

The monomer removing tower and the concentration tower are provided with liquid distributors, the polymerization liquid flows from the top to the bottom of the tower in a uniformly distributed manner, and the polymerization liquid can be fully mixed while the monomer removing and concentration effects are completed.

The online rotary viscometer 14 can detect key indexes online, can feed back main product indexes after blending at the first time, and can adjust online in time to ensure the blending effect to play a key role.

The polymerization device outputs 40m in the maintenance and driving stage³The off-grade polymer solution having a viscosity of 600 poise is stored in the recovered polymerization liquid tank 18, assuming that the polymer solution product viscosity control index is 650. + -.20 poise.

The feeding quantity of a feeding pump 2 of the single stripping tower is 5m³The viscosity of the polymer feed at this point on the line was 550 poise as shown by the analysis of data from the demonomerization feed sampling point 4, and the viscosity of the polymer product was 650 poise as shown by the analysis of data from the polymer product sampling point 15.

And starting a polymer liquid recovery pump 19, and checking the unqualified polymer liquid indexes through a polymer liquid product sampling point 21. Adjusting the frequency conversion control flow to 0.155m³The gel was filtered through a polymer recovery filter 22, which recovered polymer accounted for 3% of the total feed.

The blended polymer liquid passes through a first static mixer 5, the feeding pressure is displayed through a single removing feeding pressure detection point 7, and cascade control is formed by the blended polymer liquid and a single removing feeding pressure regulating valve 8, so that the pressure of the blended polymer liquid entering a single removing tower 9 is stable.

Theoretically calculating the retention time of the polymer liquid in the demonomerization tower 9 and the concentration tower 10 to be 5h, and increasing the ammoniation coefficient of the ammoniation facility 23 to 102 percent of the original set parameters 5h after the polymer liquid recovery pump 19 is started.

The aminated polymer liquid passes through a second static mixer 12, the viscosity is obtained between 640-650 poise through an online rotational viscometer 14, sampling is carried out at a polymer liquid product sampling point 15 for 2h for proofreading, normal sampling frequency is recovered after 3 continuous detection samples are qualified, and the qualified polymer liquid product is sent to a polymer liquid product tank 17.

The blending time of the polymerization solution is 258h, and the polymerization solution product is tracked to subsequent spinning and carbonization procedures, so that the traceability of the product is ensured.

And returning the ammonia adding coefficient before blending after the treatment of the recovered polymerization liquid is finished.

The recovery rate of the unqualified polymerization liquid can reach 100 percent, and the quality qualification rate of the polymerization liquid product is 100 percent.

Example 2

The system for recovering and treating the polymerization liquid in the monomer recovery tower in the production of carbon fiber precursors provided by the embodiment is the same as that in the embodiment 1, and the method for recovering the polymerization liquid by adopting the system is as follows:

the polymerization device outputs 40m in the maintenance and driving stage³The off-specification polymerization liquid having an ammonia neutralization degree of 0.6 is stored in the recovered polymerization liquid tank 18, and it is assumed that the control index of the ammonia neutralization degree of the polymerization liquid product is 0.8. + -. 0.05.

1. Feeding a polymerization solution; 2. a demonomerization tower feed pump; 3. a feed pump variable frequency controller; 4. a stripping feed sampling point; 5. a first static mixer; 6. a first static mixer internal; 7. a single feed removal pressure detection point; 8. a demonomerization feeding pressure regulating valve; 9. a demonomerization tower; 10. a concentration tower; 11. a discharge pump of the concentration tower; 12. a second static mixer; 13. a second static mixer internal; 14. an online rotational viscometer; 15. a polymer liquid product sampling point; 16. a three-way switch valve; 17. a polymerization liquid product tank; 18. a polymerization liquid recovery tank; 19. a polymerization liquid recovery pump; 20. a variable frequency controller of a polymer liquid recovery pump; 21. recovering a polymerization solution sampling point; 22. recovering the polymerization liquid filter; 23. and (4) an ammonia adding facility.

The feeding quantity of a feeding pump 2 of the single stripping tower is 5m³And h, the polymerization liquid product sampling point 15 analysis data shows that the neutralization degree of the polymerization liquid ammonia of the product is 0.8.

And starting a polymer liquid recovery pump 19, and checking the unqualified polymer liquid indexes through a polymer liquid product sampling point 21. Adjusting the flow rate of frequency conversion control to 0.263m³The gel was filtered through a polymer recovery filter 22, which recovered polymer accounted for 5% of the total feed.

The blended polymer liquid passes through a first static mixer 5, the feeding pressure is displayed through a single removing feeding pressure detection point 7, and cascade control is formed by the blended polymer liquid and a single removing feeding pressure regulating valve 8, so that the pressure of the blended polymer liquid entering a single removing tower 9 is stable.

Theoretically calculating the retention time of the polymer liquid in the demonomerization tower 9 and the concentration tower 10 to be 5h, and increasing the ammoniation coefficient of the ammoniation facility 23 to 0.84% 5h after the polymer liquid recovery pump 19 is started.

The aminated polymerization solution is sampled at a polymerization solution product sampling point 15 once through a second static mixer 12 for 2 hours for analysis, the ammonia neutralization value is within the range of 0.8 +/-0.05, and the normal sampling frequency is recovered after 3 continuous detection samples are qualified.

The blending time of the polymerization solution is 152h, and the polymerization solution product is tracked to subsequent spinning and carbonization procedures, so that the traceability of the product is ensured.

And returning the ammonia adding coefficient before blending after the treatment of the recovered polymerization liquid is finished.

The recovery rate of the unqualified polymerization liquid can reach 100 percent, and the quality qualification rate of the polymerization liquid product is 100 percent.