CN111825261A - Treatment system and treatment process for salt-containing organic wastewater in para-aramid production - Google Patents

Treatment system and treatment process for salt-containing organic wastewater in para-aramid production Download PDF

Info

Publication number
CN111825261A
CN111825261A CN202010737607.3A CN202010737607A CN111825261A CN 111825261 A CN111825261 A CN 111825261A CN 202010737607 A CN202010737607 A CN 202010737607A CN 111825261 A CN111825261 A CN 111825261A
Authority
CN
China
Prior art keywords
evaporator
shell
salt
liquid
solid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010737607.3A
Other languages
Chinese (zh)
Other versions
CN111825261B (en
Inventor
张文广
高金鹿
孙蓓蓓
刘忠
郑淑昀
黄彦超
候慧茹
高艳金
肖磊
魏建毅
赵辉
董菲菲
王冬冬
潘勇
张海民
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Henan Shenma Aramid Technology Development Co ltd
Original Assignee
HENAN SHENMA NYLON CHEMICAL CO Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by HENAN SHENMA NYLON CHEMICAL CO Ltd filed Critical HENAN SHENMA NYLON CHEMICAL CO Ltd
Priority to CN202010737607.3A priority Critical patent/CN111825261B/en
Publication of CN111825261A publication Critical patent/CN111825261A/en
Application granted granted Critical
Publication of CN111825261B publication Critical patent/CN111825261B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/02Treatment of water, waste water, or sewage by heating
    • C02F1/04Treatment of water, waste water, or sewage by heating by distillation or evaporation
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01DCOMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D3/00Halides of sodium, potassium or alkali metals in general
    • C01D3/04Chlorides
    • C01D3/06Preparation by working up brines; seawater or spent lyes
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01DCOMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D3/00Halides of sodium, potassium or alkali metals in general
    • C01D3/14Purification
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01FCOMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F11/00Compounds of calcium, strontium, or barium
    • C01F11/20Halides
    • C01F11/24Chlorides
    • C01F11/30Concentrating; Dehydrating; Preventing the adsorption of moisture or caking
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01FCOMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F11/00Compounds of calcium, strontium, or barium
    • C01F11/20Halides
    • C01F11/24Chlorides
    • C01F11/32Purification
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/38Treatment of water, waste water, or sewage by centrifugal separation
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00Nature of the contaminant
    • C02F2101/30Organic compounds

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Environmental & Geological Engineering (AREA)
  • Hydrology & Water Resources (AREA)
  • Materials Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Analytical Chemistry (AREA)
  • Heat Treatment Of Water, Waste Water Or Sewage (AREA)
  • Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)

Abstract

The application belongs to the technical field of wastewater treatment, and particularly relates to a treatment system and treatment process for salt-containing organic wastewater in para-aramid production. The system comprises a plurality of evaporators connected in series, a drying device, a solid-liquid separation device, a heating device and a gas phase condensation device; the upper part of the evaporator is provided with a first liquid inlet pipe, and the bottom of the evaporator is provided with a liquid outlet pipe; the liquid outlet pipe of the previous stage evaporator is connected with the first liquid inlet pipe of the next stage evaporatorAnd the liquid outlet pipe of the last stage of evaporator is connected with a solid-liquid separation device. The drying device comprises a shell and a rotary drying component arranged in the shell; the shell is of an inverted conical structure, and a heating sleeve is arranged outside the shell. In the treatment system, the NMP and the CaCl are realized by connecting a plurality of evaporators in series, separately controlling the evaporators and matching with a subsequent drying device with a special structure under the condition of not adding other precipitating agents or coagulants2And the NaCl is separated, so that the treatment cost is low.

Description

Treatment system and treatment process for salt-containing organic wastewater in para-aramid production
Technical Field
The application belongs to the technical field of wastewater treatment, and particularly relates to a treatment system and treatment process for salt-containing organic wastewater in para-aramid production.
Background
The poly-p-phenylene terephthamide (PPTA) fiber is para-aramid fiber for short, is a high-performance fiber, has excellent performances of high strength and modulus, high temperature resistance, acid and alkali resistance, light weight and the like, has the specific strength 5-6 times that of a steel wire, the specific modulus 2-3 times that of the steel wire or glass fiber, the toughness 2 times that of the steel wire and the weight only about 20 percent of that of the steel wire, and is widely applied to the civil and national defense fields. The liquid collected in the polymerization section in the production process of para-aramid fiber is called mother liquid, and CaCl with low concentration is contained in the mother liquid2NaCl, N-methylpyrrolidone (NMP) and large amounts of H2And O. In the subsequent solvent section, CHCl is used3Extracting the NMP in the mother liquor, recycling the extracted NMP, and using the remaining salt-containing water solution as the salt-containing wastewater of the solvent section. Although the solvent section can recover most of NMP, the recovery rate reaches 98%, the NMP is very soluble in water, and the salt-containing wastewater after extraction still contains a small amount of NMP. Therefore, the component in the salt-containing organic wastewater generated in the working section of the para-aramid fiber solvent is CaCl2、NaCl、H2O, NMP, basically consistent with the mother liquor, wherein the salt content is generally 3.5-5%, and CaCl2And NaCl in a mass ratio of about 4:1, and the content of NMP is 800-3000 ppm.
Because the salt content and NMP content in the salt-containing organic wastewater in the para-aramid solvent working section are far beyond the normal discharge index, the salt content and NMP content can not be directly discharged, and wastewater treatment is needed, but the problems of treating the wastewater at present mainly comprise: 1) because the content of chloride ions far exceeds the maximum chloride ion standard of biochemical treatment (the content of chloride ions required by biochemical treatment is less than 0.6 percent), biochemical bacteria can be directly killed, and organic matters can not be directly degraded by biochemical treatment; 2) wherein CaCl is2Similar to NaCl in chemical nature, it is difficult to isolate it by simple methods. At present, some devices and processes for treating mother liquor in the production process of para-aramid fiber exist, but the content of each component of salt-containing organic wastewater obtained in a solvent working section is greatly different from that of the mother liquor, so that the device and the process for treating the salt-containing organic wastewater by using the existing mother liquor are not suitable and are not economical. How to realize low cost and effectively add NMP (or NMP aqueous solution) and CaCl2、NaClThe three are separated, so that the salt-containing organic wastewater in the para-aramid solvent workshop section is effectively treated, and the problem to be solved urgently in the para-aramid industry is solved.
Disclosure of Invention
In order to solve the technical problems, the application aims to provide a treatment system for salt-containing organic wastewater in para-aramid production, and the treatment system can be used for treating para-aramid production wastewater, especially NMP and CaCl in production wastewater of a para-aramid solvent workshop section2And NaCl are separated, and the treatment process is simple and effective; based on a general inventive concept, the application also comprises a process for treating the salt-containing organic wastewater by using the treatment system.
In order to achieve the technical purpose, the following technical scheme is adopted in the application:
a treatment system for salt-containing organic wastewater in para-aramid production comprises a plurality of evaporators connected in series, a drying device, a solid-liquid separation device, a heating device and a gas-phase condensation device;
the upper part of the evaporator is provided with a first liquid inlet pipe, and the bottom of the evaporator is provided with a liquid outlet pipe; the liquid outlet pipe of the previous stage evaporator is connected with the first liquid inlet pipe of the next stage evaporator, and the liquid outlet pipe of the last stage evaporator is connected with the solid-liquid separation device; the side wall of the evaporator is also provided with a second liquid inlet pipe which is communicated with the bottom liquid outlet pipe so as to form an internal liquid circulation circuit, and the heating device is positioned on the internal liquid circulation circuit; the evaporator is also provided with a gas phase pipeline and is communicated with a gas phase condensing device through the gas phase pipeline;
the drying device comprises a shell and a rotary drying component arranged in the shell; the shell is of an inverted conical structure, and a heating sleeve is arranged outside the shell; the top of the shell is provided with a concentrated solution inlet pipe, and concentrated filtrate of the last stage evaporator after solid-liquid separation is guided into the shell through a concentrated solution inlet pipe; a discharge hole is formed in the bottom of the shell, and dried solids are discharged from the discharge hole; the rotary drying component comprises a rotating shaft, a connecting rod and a scraper; the top end of the rotating shaft is rotatably connected with the top of the shell; a plurality of connecting rods are sequentially arranged on the rotating shaft from bottom to top; the connecting rod is perpendicular to the rotating shaft, the length of the connecting rod is matched with the inner diameter of the shell on the same horizontal plane, and the scraping plate arranged at the end part of the connecting rod can scrape attachments on the inner wall of the shell;
the gas phase condensing device comprises a condenser, a condensate liquid storage tank and a vacuum pump; the condenser is communicated with the vacuum pump through a gas phase pipeline, and the condenser is communicated with the condensate liquid storage tank through a condensate liquid discharge pipe.
Preferably, the last stage of evaporator is further provided with a concentrated liquid discharge pipe, and the concentrated liquid discharge pipe is communicated with a concentrated liquid inlet pipe of the drying device. The drain pipe is connected with the drying device, and the concentrated solution in the last stage of evaporator can be directly discharged into the drying device for drying.
Preferably, an automatic online sodium ion detection device is arranged in the last stage of evaporator. After three-stage evaporation concentration, a large amount of NaCl crystals can be separated out at the bottom of the three-stage evaporator, and an online sodium ion automatic detection device is arranged to detect the concentration of sodium ions in a concentrated solution in real time and judge a reaction end point.
Preferably, an umbrella-shaped baffle is arranged on the rotating shaft; the umbrella-shaped baffle is positioned above the connecting rod; the umbrella-shaped baffle inclines downwards by taking the rotating shaft as a center, and a certain gap is reserved between the bottom of the umbrella-shaped baffle and the inner wall of the shell. The evaporation area can be increased by arranging the umbrella-shaped baffle: the concentrated solution entering the shell firstly falls on the umbrella-shaped baffle, the umbrella-shaped baffle uniformly distributes the concentrated solution to the inner wall of the shell in the rotating process, and the concentrated solution is concentrated, separated out and dried in the sliding process along the inner wall of the shell, so that the drying efficiency of the concentrated solution is effectively improved.
Preferably, the scraper blade and the inner wall of the shell are arranged in parallel, and a gap of 3-10 mm is reserved between the scraper blade and the inner wall of the shell. The scraper plates arranged in parallel with the inner wall of the shell are used for conveniently scraping off dry solids attached to the inner part of the shell.
Preferably, a gas phase pipeline is arranged at the top of the shell, and the drying device is communicated with the condenser through the gas phase pipeline.
A process for treating salt-containing organic wastewater in para-aramid production by using the treatment system specifically comprises the following steps:
1) conveying salt-containing organic wastewater in para-aramid production to a primary evaporator for evaporation concentration, wherein the control range of vacuum degree in the primary evaporator is-70 to-90 kpa, the temperature is controlled to be 65-75 ℃, and the concentration of salt after concentration is 5-8%;
2) delivering the concentrated wastewater from a liquid outlet pipe of the primary evaporator to a secondary evaporator for continuous evaporation, controlling the vacuum degree to be-75 to-95 kpa, the temperature to be 65-75 ℃, and the concentration of the concentrated salt to be 10-15%;
3) delivering the concentrated wastewater from a liquid outlet pipe of the second-stage evaporator to a third-stage evaporator for continuous evaporation, controlling the vacuum degree to be-85 to-95 kpa, the temperature to be 60 to 68 ℃, and the concentration of the concentrated salt to be 35 to 45 percent;
4) the gas evaporated in the processes of the steps 1) to 3) enters a condenser through a gas phase pipeline, and the obtained condensate is the water solution containing the NMP and is discharged into a condensate liquid storage tank;
5) introducing the concentrated wastewater obtained in the step 3) into a solid-liquid separation device for solid-liquid separation, wherein the obtained solid is NaCl; after solid-liquid separation, the filtrate is led into a drying device for further drying;
6) adjusting the rotating speed of a rotating shaft of the drying device to be 10-100 rpm and the drying temperature to be 180-200 ℃, scraping the dried solid attached to the inner wall of the shell by a rotating scraper and discharging the solid from a discharge hole, wherein the main component of the dried solid is CaCl2
Preferably, the vacuum degree in the step 1) is-80 kpa, and the temperature is 70 ℃; the vacuum degree in the step 2) is-85 kpa, and the temperature is 66 ℃; the vacuum degree in the step 3) is-92 kpa, and the temperature is 62 ℃.
Preferably, the vacuum degree in the step 6) is-90 kpa.
Preferably, the salt-containing organic wastewater in the para-aramid production is preheated at the preheating temperature of 30-50 ℃ before entering a first-stage evaporator.
In the treatment system, the NMP and the CaCl are realized by connecting a plurality of evaporators in series, separately controlling the evaporators and matching with a subsequent drying device with a special structure under the condition of not adding other precipitating agents or coagulants2Separation of NaClAnd the treatment cost is low. After the treatment by the device, NaCl crystals with the purity of more than 99 percent can be obtained in the solid-liquid separation step, and the recovery rate of the NaCl crystals is more than 74.29 percent. Through the evaporation and condensation process, more than 75% of NMP can be recovered in the condensate liquid storage tank. The main component of the final dry product is CaCl containing crystal water2In which is CaCl2∙2H2O and CaCl2∙4H2The mass ratio of O is about 1:1 and contains no more than 4.15% NaCl. The final dried product can be subjected to recrystallization or other refining processes to obtain CaCl with higher purity2The product can also be directly used for other purposes, such as sewage treatment in the monocrystalline silicon industry.
The processing system is simple in structure and strong in controllability; the process has high treatment efficiency, is easy to realize, and provides an economic and effective feasible way for large-scale continuous treatment of salt-containing organic wastewater in the working section of the para-aramid solvent.
Drawings
FIG. 1 is a schematic connection diagram of components of a salt-containing organic wastewater treatment system for para-aramid production.
Detailed Description
The present application is described in further detail below with reference to specific examples. In the embodiments, terms such as "upper", "lower", "inner" and "outer" are used only for illustrating the relative positional relationship of the respective structures, and are not used to limit the range in which the present application can be implemented, and changes or adjustments of the relative relationship are considered to be the scope in which the present application can be implemented without substantial technical changes.
Example 1
A treatment system for salt-containing organic wastewater in para-aramid production comprises a primary evaporator 1, a secondary evaporator 2, a tertiary evaporator 3, a drying device, a centrifugal machine 8, a heat exchanger and a gas phase condensing device which are connected in series in three stages;
the upper parts of the evaporators are provided with first liquid inlet pipes 6, and salt-containing organic wastewater in para-aramid production enters the evaporators from the first liquid inlet pipes 6; and a heat exchanger 7 is arranged on the first liquid inlet pipe 6 and can be used for preheating wastewater. The bottom of each evaporator is provided with a liquid outlet pipe 9, and the liquid outlet pipe 9 of the previous evaporator is connected with the first liquid inlet pipe 6 of the next evaporator through a connecting pipe, so that the evaporation concentrate in the first evaporator 1 can enter the second evaporator 2 for continuous evaporation, and the evaporation concentrate in the second evaporator 2 can enter the third evaporator 3 for continuous evaporation, thereby improving the evaporation efficiency; a circulating water pump 21 is arranged on the liquid outlet pipe 9. A second liquid inlet pipe 10 is further arranged on the side wall of the evaporator, an internal liquid circulation circuit is formed by the second liquid inlet pipe 10 and the liquid outlet pipe 9 through a connecting pipe, and a forced circulation pump 20 and a heat exchanger 7 are arranged on the internal liquid circulation circuit; waste water at the bottom of the evaporator is firstly circulated in an internal feed liquid circulation line by starting a forced circulation pump 20, the temperature of water in a pipeline is raised and heated by a heat exchanger 7 in the circulation process, the temperature of the waste water in the evaporator is controlled within a certain range, and evaporation and concentration of the waste water in the evaporator are realized; after the concentrated solution is concentrated to a certain degree, the circulating water pump 21 is started to pump out the concentrated solution, and the concentrated solution is sent to the next stage of evaporator to continue evaporation and concentration.
After the salt-containing organic wastewater is subjected to three-stage evaporation and concentration, a large amount of crystals are separated out from the bottom of the three-stage evaporator 3, and the component of the crystals is mainly NaCl. An automatic online sodium ion detector (not shown in the figure) is arranged in the third-stage evaporator 3, the concentration degree can be monitored online by detecting the concentration of sodium ions in the concentrated solution, the reaction end point is judged, and the sodium chloride can be discharged and discharged when the concentration of NaCl in the wastewater is 2.23-3.13%. The concentrated solution containing NaCl crystals is discharged from a liquid outlet pipe of the three-stage evaporator 3 and enters a centrifugal machine 8 for centrifugation; directly drying the solid after centrifugation to obtain NaCl crystals; after centrifugation, the filtrate enters a drying device from a concentrated solution inlet pipe 11 for further concentration and drying. In order to improve the concentration efficiency, a concentrated solution discharge pipe 12 is also arranged on the third-stage evaporator 3, and the concentrated solution discharge pipe 12 is communicated with a concentrated solution inlet pipe 11; when the concentration of NaCl in the concentrated wastewater in the three-stage evaporator 3 is reduced to 2.23-3.13%, the concentrated supernatant without solid crystals on the upper layer can be directly discharged into a drying device for drying, so that the treatment capacity of subsequent centrifugal operation is reduced.
The drying device comprises a shell 4 and a rotary drying component arranged in the shell 4; the shell 4 is an inverted conical knotThe outer part of the shell 4 is provided with a heating jacket (not shown in the figure); the top of the shell 4 is connected with a concentrated solution inlet pipe 11, and the centrifuged filtrate enters the shell 4 through the concentrated solution inlet pipe 11 to be dried; a discharge hole is formed in the bottom of the shell 4, and dried solids are discharged from the discharge hole; the obtained dry solid contains CaCl as main ingredient2. The rotary drying component comprises a rotating shaft 17, an umbrella-shaped baffle 19 and a plurality of horizontally arranged connecting rods 18 which are arranged on the rotating shaft 17, and a scraper 181 which is arranged at the end part of the connecting rods 18. The rotating shaft 17 is located on the axial center line of the shell 4, and the top end of the rotating shaft 17 is rotatably connected with the top of the shell 4. The umbrella-shaped baffle 19 is positioned at the upper part of the rotating shaft 17, the umbrella-shaped baffle 19 inclines downwards by taking the rotating shaft 17 as the center, and a certain gap is reserved between the bottom of the umbrella-shaped baffle 19 and the inner wall of the shell 4; the evaporation area inside the housing 4 can be greatly increased by providing the umbrella-shaped baffle 19: the concentrated solution entering the shell 4 firstly falls on the umbrella-shaped baffle 19, the umbrella-shaped baffle 19 uniformly distributes the concentrated solution to the inner wall of the shell 4 in the rotating process, and the concentrated solution is concentrated, separated out and dried in the sliding process along the inner wall of the shell 4, so that the drying efficiency of the concentrated solution is effectively improved. A connecting rod 18 is arranged below the umbrella-shaped baffle 19, the connecting rod 18 is perpendicular to the rotating shaft 17, and the length of the connecting rod 18 is matched with the inner diameter of the shell 4 on the same horizontal plane. The scrapers 181 are located at both ends of the link 18; the two ends of the scraper 181 extend to the upper and lower sides of the connecting rod 18, and the scraper 181 is approximately parallel to the inner wall of the casing 4, so as to ensure that the scraper 181 scrapes the inner wall of the casing 4 to the largest possible area. In order to avoid the friction damage of the scraper 181 on the inner wall of the shell 4, a gap of 3-10 mm is left between the scraper 181 and the inner wall of the shell 4.
The top of the first-stage evaporator 1, the top of the second-stage evaporator 2, the top of the third-stage evaporator 3 and the top of the shell 4 are communicated with a gas phase pipeline 13, and the evaporator and the drying device are communicated with a gas phase condensing device through the gas phase pipeline 13. The gas phase condensing device comprises a condenser 14, a condensate liquid storage tank 5 and a vacuum pump 15; the condenser 14 is communicated with the vacuum pump 15 through a gas phase pipeline, and the condenser 14 is communicated with the condensate storage tank 5 through a condensate drain pipe 16. Gas evaporated in the evaporation and drying processes is pumped out by a vacuum pump 15 and enters a condenser 14 for cooling and condensation through a gas phase pipeline 13, and the obtained condensate is the water solution containing the NMP and is discharged into a condensate liquid storage tank 5 for storage.
In the treatment system of the embodiment, the NMP, the CaCl and the like are realized by connecting a plurality of evaporators in series, controlling the evaporators in a step-by-step manner and matching with a subsequent drying device with a special structure under the condition of not adding other precipitating agents or coagulants2The NaCl is separated, and the treatment cost is low; and the three components do not change in nature, and other impurities are not introduced, so that the method is favorable for further extraction and purification of the three components.
Example 2
A process for treating salt-containing organic wastewater in para-aramid production by using the treatment system in the embodiment 1 comprises the following specific steps:
the salt-containing organic wastewater generated in a para-aramid solvent section is preheated to 40 ℃, and then enters a primary evaporator, wherein the salt content is about 3.5%, and the NMP content is 1600 ppm.
Controlling the vacuum degree of a primary evaporator to be-80 kpa and the temperature to be 70 ℃, and concentrating the salt-containing organic wastewater to be about 5.44%; the first-stage wastewater enters a second-stage evaporator, and the salt-containing organic wastewater is concentrated to about 11.56% under the conditions that the vacuum degree is-85 kpa and the temperature is 66 ℃; and the secondary wastewater enters a three-stage evaporator, and after the secondary wastewater is concentrated under the conditions that the vacuum degree is-92 kpa and the temperature is 62 ℃, the salt content is about 40.62 percent. The NaCl concentration in the concentrated solution is 2.61% detected by a sodium ion on-line automatic monitor, and a large amount of crystals are separated out at the bottom of the three-stage evaporator.
And conveying the mixed concentrated solution containing the crystal particles to a centrifugal machine for centrifugation by using a discharge pipe at the bottom of the three-stage evaporator, drying the obtained solid, and measuring the components of the solid, wherein the obtained solid is NaCl with the purity of 99.2 percent. And conveying the concentrated solution obtained by solid-liquid separation and the concentrated wastewater in the three-stage evaporator to a drying device for further concentration and drying.
The rotating speed of a rotating shaft in the drying device is adjusted to be 50rpm, the temperature is controlled to be 190 ℃, and the vacuum degree is controlled to be-90 kpa. In the drying process, the dried solid attached to the inner wall is scraped by the scraper and falls down from the discharge hole. The obtained dried solid was determined to be mainly CaCl2And a small amount of NaCl.
In the evaporation and drying processes, gas evaporated from the evaporator is pumped out by a vacuum pump, enters a condenser through a gas phase pipeline for cooling and condensation, the obtained condensate is the water solution containing the NMP, and the content of the NMP in a liquid storage tank of the condensate is measured to be 1200 ppm.
In practical production, the evaporation concentration process is continuously carried out: and when the concentrated wastewater in the first-stage evaporator flows into the second-stage evaporator, the first-stage evaporator replenishes new wastewater and continues to process. After accounting, the treatment system is utilized to continuously treat the salt-containing organic wastewater in the para-aramid solvent working section for 24 hours, wherein the salt content is about 140 kg. After centrifugal drying, 20.8kg of NaCl solid is obtained, and the recovery rate of NaCl is about 74.29%. During the condensation, the recovery of NMP was about 75%.
After drying by the drying device, about 173.7kg of dried solid can be obtained, and the content of sodium ions in the dried solid can be measured to obtain the content of sodium chloride in the dried solid of 7.2kg, wherein the mass percentage is 4.15%. The rest is CaCl containing crystal water2Determined to contain CaCl therein2∙2H254.5kg of O and CaCl2∙4H2O was 112 kg. According to CaCl2The CaCl is calculated by the above-mentioned treatment2Recovery of nearly 100%, but due to final CaCl2A small amount of NaCl and a small amount of NMP which is not distilled are mixed in the product, and CaCl with higher purity is obtained subsequently2The product can be subjected to subsequent recrystallization or other refining processes; the obtained CaCl containing a small amount of NaCl and a trace amount of NMP2The product can also be directly used, such as used in the wastewater treatment process of the monocrystalline silicon industry.
Example 3
A process for treating salt-containing organic wastewater in para-aramid production by using the treatment system in the embodiment 1 comprises the following specific steps:
the salt-containing organic wastewater in the para-aramid solvent section is preheated to 40 ℃, and then is input into a first-stage evaporator, wherein the salt content is about 4.2%, and the NMP content is 2000 ppm.
Concentrating the salt-containing organic wastewater to about 6.45% by a first-stage evaporator under the conditions of vacuum degree of-80 kpa and temperature of 70 ℃; the first-stage wastewater enters a second-stage evaporator, and the salt-containing organic wastewater is concentrated to about 12.32% under the conditions that the vacuum degree is-85 kpa and the temperature is 66 ℃; the secondary wastewater enters a three-stage evaporator, and after concentration under the conditions of vacuum degree of-92 kpa and temperature of 62 ℃, the salt content is about 40.89%. The NaCl concentration is 2.61% detected by a sodium ion on-line automatic monitor, and a large amount of NaCl crystals are separated out at the bottom of the three-stage evaporator.
And conveying the mixed concentrated solution containing the crystal particles to a centrifugal machine for centrifugation by using a discharge pipe at the bottom of the three-stage evaporator, drying the obtained solid, and measuring the components of the solid, wherein the obtained solid is NaCl with the purity of 98.7 percent. And conveying the concentrated solution obtained by solid-liquid separation and the concentrated wastewater in the three-stage evaporator to a drying device for further concentration and drying.
The rotating speed of a rotating shaft in the drying device is adjusted to be 50rpm, the temperature is controlled to be 190 ℃, and the vacuum degree is controlled to be-90 kpa. In the drying process, the dried solid attached to the inner wall is scraped by the scraper and falls down through the discharge hole to be discharged. The obtained dried solid was determined to be mainly CaCl2And a small amount of NaCl.
In the evaporation and drying processes, gas evaporated from the evaporator is pumped out by a vacuum pump, enters a condenser through a gas phase pipeline for cooling and condensation, the obtained condensate is the water solution containing the NMP, and the content of the NMP in a condensate liquid storage tank is 1600ppm by measurement.
After accounting, the treatment system is utilized to continuously treat the salt-containing organic wastewater 4t in the co-treatment para-aramid solvent working section for 24 hours, wherein the salt content is about 168 kg. After measurement and centrifugal drying, 25.9kg of NaCl solid is obtained, and the recovery rate of NaCl is about 77.08%. During the condensation, the recovery of NMP was about 80%. After drying by the drying device, about 207.48kg of dried solid can be obtained, and the content of sodium ions in the dried solid can be measured, wherein the content of sodium chloride is 7.7kg, and the mass percentage is 3.71%. The rest is CaCl containing crystal water2Determined to contain CaCl therein2∙2H2O is 65.38kg, CaCl2∙4H2The O content was 134.4 kg.
Example 4
A process for treating salt-containing organic wastewater in para-aramid production by using the treatment system in the embodiment 1 comprises the following specific steps:
the salt-containing organic wastewater in the para-aramid solvent section is preheated to 40 ℃, and then is conveyed into a primary evaporator, wherein the salt content is about 5%, and the NMP content is 2200 ppm.
Concentrating the salt-containing organic wastewater to about 7.05% by a first-stage evaporator under the conditions of vacuum degree of-80 kpa and temperature of 70 ℃; the first-stage wastewater enters a second-stage evaporator, and the salt-containing organic wastewater is concentrated to about 13.07 percent under the conditions that the vacuum degree is-85 kpa and the temperature is 66 ℃; and the secondary wastewater enters a three-stage evaporator, and after the secondary wastewater is concentrated under the conditions that the vacuum degree is-92 kpa and the temperature is 62 ℃, the salt content is about 40.96 percent. The NaCl concentration is 2.61% detected by a sodium ion on-line automatic monitor, and a large amount of NaCl crystals are separated out at the bottom of the three-stage evaporator.
And conveying the mixed concentrated solution containing the crystal particles to a centrifugal machine for centrifugation by using a discharge pipe at the bottom of the three-stage evaporator, drying the obtained solid, and measuring the components of the solid, wherein the obtained solid is NaCl with the purity of 99.0 percent. And conveying the concentrated solution obtained by solid-liquid separation and the concentrated wastewater in the three-stage evaporator to a drying device for further concentration and drying.
The rotating speed of a rotating shaft in the drying device is adjusted to be 50rpm, the temperature is controlled to be 190 ℃, and the vacuum degree is controlled to be-90 kpa. In the drying process, the dried solid attached to the inner wall is scraped by the scraper and falls down through the discharge hole to be discharged. The obtained dried solid was determined to be mainly CaCl2And a small amount of NaCl.
In the evaporation and drying processes, gas evaporated from the evaporator is pumped out by a vacuum pump, enters a condenser through a gas phase pipeline for cooling and condensation, the obtained condensate is the water solution containing the NMP, and the content of the NMP in a liquid storage tank of the condensate is 1800ppm by measurement.
After accounting, the treatment system is utilized to continuously treat 4t of salt-containing organic wastewater in a para-aramid solvent working section for 24 hours, wherein the salt content is about 200 kg. After measurement and centrifugal drying, 30.4kg of NaCl solid is obtained, and the recovery rate of NaCl is about 76%. During the condensation, the NMP recovery was about 81.82%. Drying with a drying device to obtain dried solid about 247.44kg, and measuring sodium ion content in the dried solid, wherein the sodium ion content contains chlorideThe amount of sodium was 9.6kg, the mass ratio was 3.87%. The rest is CaCl containing crystal water2Determined to contain CaCl therein2∙2H277.84kg of O and CaCl2∙4H2O was 160 kg.

Claims (10)

1. The utility model provides a processing system who contains salt organic waste water in para-aramid production which characterized in that: the system comprises a plurality of evaporators connected in series, a drying device, a solid-liquid separation device, a heating device and a gas phase condensation device;
the upper part of the evaporator is provided with a first liquid inlet pipe, and the bottom of the evaporator is provided with a liquid outlet pipe; the liquid outlet pipe of the previous stage evaporator is connected with the first liquid inlet pipe of the next stage evaporator, and the liquid outlet pipe of the last stage evaporator is connected with the solid-liquid separation device; the side wall of the evaporator is also provided with a second liquid inlet pipe which is communicated with the bottom liquid outlet pipe so as to form an internal liquid circulation circuit, and the heating device is positioned on the internal liquid circulation circuit; the evaporator is also provided with a gas phase pipeline and is communicated with a gas phase condensing device through the gas phase pipeline;
the drying device comprises a shell and a rotary drying component arranged in the shell; the shell is of an inverted conical structure, and a heating sleeve is arranged outside the shell; the top of the shell is provided with a concentrated solution inlet pipe, and concentrated filtrate of the last stage evaporator after solid-liquid separation is guided into the shell through a concentrated solution inlet pipe; a discharge hole is formed in the bottom of the shell, and dried solids are discharged from the discharge hole; the rotary drying component comprises a rotating shaft, a connecting rod and a scraper; the top end of the rotating shaft is rotatably connected with the top of the shell; a plurality of connecting rods are sequentially arranged on the rotating shaft from bottom to top; the connecting rod is perpendicular to the rotating shaft, the length of the connecting rod is matched with the inner diameter of the shell on the same horizontal plane, and the scraping plate arranged at the end part of the connecting rod can scrape attachments on the inner wall of the shell;
the gas phase condensing device comprises a condenser, a condensate liquid storage tank and a vacuum pump; the condenser is communicated with the vacuum pump through a gas phase pipeline, and the condenser is communicated with the condensate liquid storage tank through a condensate liquid discharge pipe.
2. The processing system of claim 1, wherein: and the last-stage evaporator is also provided with a concentrated solution drain pipe which is communicated with a concentrated solution inlet pipe of the drying device.
3. The processing system of claim 2, wherein: and a sodium ion automatic online detection device is arranged in the last stage of evaporator.
4. The processing system of claim 1, wherein: an umbrella-shaped baffle is arranged on the rotating shaft; the umbrella-shaped baffle is positioned above the connecting rod; the umbrella-shaped baffle inclines downwards by taking the rotating shaft as a center, and a certain gap is reserved between the bottom of the umbrella-shaped baffle and the inner wall of the shell.
5. The processing system of claim 4, wherein: the scraper blade and the inner wall of the shell are arranged in parallel, and a gap of 3-10 mm is reserved between the scraper blade and the inner wall of the shell.
6. The processing system of any of claims 1 to 5, wherein: the top of the shell is provided with a gas phase pipeline, and the drying device is communicated with the condenser through the gas phase pipeline.
7. The process for treating the salt-containing organic wastewater in the production of para-aramid by using the treatment system of claim 1 is characterized by comprising the following steps:
1) conveying salt-containing organic wastewater in para-aramid production to a primary evaporator for evaporation concentration, wherein the control range of vacuum degree in the primary evaporator is-70 to-90 kpa, the temperature is controlled to be 65-75 ℃, and the concentration of salt after concentration is 5-8%;
2) delivering the concentrated wastewater from a liquid outlet pipe of the primary evaporator to a secondary evaporator for continuous evaporation, controlling the vacuum degree to be-75 to-95 kpa, the temperature to be 65-75 ℃, and the concentration of the concentrated salt to be 10-15%;
3) delivering the concentrated wastewater from a liquid outlet pipe of the second-stage evaporator to a third-stage evaporator for continuous evaporation, controlling the vacuum degree to be-85 to-95 kpa, the temperature to be 60 to 68 ℃, and the concentration of the concentrated salt to be 35 to 45 percent;
4) the gas evaporated in the processes of the steps 1) to 3) enters a condenser through a gas phase pipeline, and the obtained condensate is the water solution containing the NMP and is discharged into a condensate liquid storage tank;
5) introducing the concentrated wastewater obtained in the step 3) into a solid-liquid separation device for solid-liquid separation, wherein the obtained solid is NaCl; after solid-liquid separation, the filtrate is led into a drying device for further drying;
6) adjusting the rotating speed of a rotating shaft of the drying device to be 10-100 rpm, and the drying temperature to be 180-200 ℃; the dried solid adhered to the inner wall of the shell is scraped by the rotating scraper and falls into a discharge hole for discharge, and the main component of the dried solid is CaCl2
8. The process of claim 7, wherein: the vacuum degree in the step 1) is-80 kpa, and the temperature is 70 ℃; the vacuum degree in the step 2) is-85 kpa, and the temperature is 66 ℃; the vacuum degree in the step 3) is-92 kpa, and the temperature is 62 ℃.
9. The process of claim 7, wherein: the vacuum degree of the step 6) is-90 kpa.
10. The process of any one of claims 7 to 9, wherein: the salt-containing organic wastewater in the production of the para-aramid fiber is preheated at the preheating temperature of 30-50 ℃ before entering a primary evaporator.
CN202010737607.3A 2020-07-28 2020-07-28 Treatment system and treatment process for salt-containing organic wastewater in para-aramid production Active CN111825261B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010737607.3A CN111825261B (en) 2020-07-28 2020-07-28 Treatment system and treatment process for salt-containing organic wastewater in para-aramid production

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010737607.3A CN111825261B (en) 2020-07-28 2020-07-28 Treatment system and treatment process for salt-containing organic wastewater in para-aramid production

Publications (2)

Publication Number Publication Date
CN111825261A true CN111825261A (en) 2020-10-27
CN111825261B CN111825261B (en) 2024-01-23

Family

ID=72925729

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010737607.3A Active CN111825261B (en) 2020-07-28 2020-07-28 Treatment system and treatment process for salt-containing organic wastewater in para-aramid production

Country Status (1)

Country Link
CN (1) CN111825261B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111807593A (en) * 2020-07-23 2020-10-23 河南神马尼龙化工有限责任公司 Integrated device and process for treating and utilizing salt-containing organic wastewater in para-aramid solvent workshop section

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20040026202A (en) * 2002-09-23 2004-03-30 주식회사 세화엔스텍 method of evaporatoring for vacuum evaporator
CN101805456A (en) * 2010-03-16 2010-08-18 苏州兆达特纤科技有限公司 Method for reclaiming solvent in poly(p-phenytene terephthalamide)resin production
CN104876245A (en) * 2015-05-11 2015-09-02 华东理工大学 Method for separating sodium chloride and calcium chloride in alkali preparation waste solution by crystallization
CN110917663A (en) * 2019-11-04 2020-03-27 恒天海龙(潍坊)新材料有限责任公司 Continuous defoaming device and method for solvent spinning cellulose spinning solution
CN212387914U (en) * 2020-07-28 2021-01-22 河南神马尼龙化工有限责任公司 Processing system who contains salt organic waste water in para-aramid production

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20040026202A (en) * 2002-09-23 2004-03-30 주식회사 세화엔스텍 method of evaporatoring for vacuum evaporator
CN101805456A (en) * 2010-03-16 2010-08-18 苏州兆达特纤科技有限公司 Method for reclaiming solvent in poly(p-phenytene terephthalamide)resin production
CN104876245A (en) * 2015-05-11 2015-09-02 华东理工大学 Method for separating sodium chloride and calcium chloride in alkali preparation waste solution by crystallization
CN110917663A (en) * 2019-11-04 2020-03-27 恒天海龙(潍坊)新材料有限责任公司 Continuous defoaming device and method for solvent spinning cellulose spinning solution
CN212387914U (en) * 2020-07-28 2021-01-22 河南神马尼龙化工有限责任公司 Processing system who contains salt organic waste water in para-aramid production

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111807593A (en) * 2020-07-23 2020-10-23 河南神马尼龙化工有限责任公司 Integrated device and process for treating and utilizing salt-containing organic wastewater in para-aramid solvent workshop section
CN111807593B (en) * 2020-07-23 2023-07-18 河南神马芳纶技术开发有限公司 Salt-containing organic wastewater treatment and utilization integrated device and process for para-aramid solvent working section

Also Published As

Publication number Publication date
CN111825261B (en) 2024-01-23

Similar Documents

Publication Publication Date Title
CN105036222B (en) A kind of recovery and treatment method of high-salt wastewater
CN104926011B (en) The evaporative crystallization zero-discharge treatment system and processing method of a kind of high-COD waste water
WO2006094437A1 (en) A method and an multi-effect evaporation for waste water of alkylene oxides
CN104973726A (en) Recovery processing method of high salinity wastewater containing sodium chloride and sodium sulfate
CN113149059B (en) Method and system for crystallization separation of fly ash water washing liquid and separation and purification of sodium salt and potassium salt based on seed crystal method
CN110615456B (en) Device and process for continuously producing aluminum sulfate octadecahydrate
CN107096249A (en) The high strong brine sub-prime crystallization complexes of Treated sewage reusing and handling process
CN212387914U (en) Processing system who contains salt organic waste water in para-aramid production
CN111825261B (en) Treatment system and treatment process for salt-containing organic wastewater in para-aramid production
CN109848169A (en) A kind of organic saliferous breeze refinement treatment process
CN212532622U (en) Salt-containing organic wastewater treatment and utilization integrated device for para-aramid solvent workshop section
CN211971803U (en) Novel materialized wastewater triple-effect evaporation system
CN212174689U (en) Contain sodium sulfate salt and sodium sulfite salt dinaphthol effluent disposal system
CN1214272A (en) Continuous stirring vacuum sodium sulfate crystallization technology
CN205710266U (en) Electroplating waste processing equipment
CN110790440B (en) High COD high salt wastewater treatment system
CN210795831U (en) Double-effect falling film and single-effect forced circulation double-row double-steam-inlet MVR evaporation crystallization system
CN210559423U (en) Thermal denitration system for dechlorination light salt brine
CN104892621B (en) Energy-saving emission-reduction process for producing pyromellitic dianhydride in solvent refining method
CN106629941B (en) Nickel-containing wastewater treatment system
CN213231891U (en) Automatic deoiling device in pharmaceutical intermediate waste water MVR evaporation crystallization
CN218924692U (en) Recovery system of lithium precipitation mother liquor
CN115637327B (en) Coupling device for extracting lithium from salt lake based on ultrasonic assistance and application method thereof
CN216573122U (en) Production equipment for melting and converting ammonium thiocyanate into thiourea
CN110128283B (en) 3, 5-diaminobenzoic acid production system and process

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
TA01 Transfer of patent application right
TA01 Transfer of patent application right

Effective date of registration: 20230317

Address after: Room 412, Management Committee of Pingdingshan Nylon New Material Industry Cluster, Gongdian Town, Ye County, Pingdingshan City, Henan Province, 467200

Applicant after: Henan Shenma Aramid Technology Development Co.,Ltd.

Address before: 467013 high tech Development Zone, east section of Jianshe Road, Pingdingshan City, Henan Province

Applicant before: HENAN SHENMA NYLON CHEMICAL Co.,Ltd.

GR01 Patent grant
GR01 Patent grant