Polyoxymethylene dioxolane extraction lye recycling device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 新疆心连心能源化工有限公司
- Filing Date
- 2025-06-30
- Publication Date
- 2026-07-24
Smart Images
Figure CN224548113U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of waste alkali recycling technology, and is a polyoxymethylene dioxane extraction alkali recycling device. Background Technology
[0002] In the traditional polyoxymethylene (POM) production process, the dioxane (DOX) system plays a crucial role. POM is a high-performance thermoplastic engineering plastic widely used in the automotive, electronics, and industrial equipment industries due to its high strength, abrasion resistance, and chemical resistance. DOX is one of the key raw materials for synthesizing POM, and its purity directly affects the quality of the final POM product.
[0003] In the dioxapentane extraction process, an extraction tower is used. The extraction tower is the core of the liquid-liquid extraction device, utilizing the difference in solubility of different substances in two immiscible solvents to achieve separation and purification. The sodium hydroxide aqueous solution at the bottom of the extraction tower is typically used to neutralize or wash acidic substances generated during the process. Simultaneously, a decanter is used to separate liquid layers of different densities. The waste alkaline solutions generated from these two processes were originally designed to be intermittently discharged into a waste alkaline solution storage tank and planned to be sent to the polyoxymethylene (POM) wastewater treatment system for neutralizing wastewater generated by the POM plant.
[0004] However, problems arose during actual operation. The amount of waste alkaline solution generated during the dioxane extraction process exceeded design expectations. Analysis revealed a high salt content in the waste alkaline solution, reaching 20,930 ppm, far exceeding the designed 8,000 ppm. Polyoxymethylene (POM) wastewater treatment systems typically rely on the activated sludge process, in which microorganisms (bacteria) are the primary agents for decomposing organic matter. The high salt content in the waste alkaline solution generated during the dioxane extraction process inhibits microorganisms, resulting in low sludge activity, substandard wastewater treatment, and a severe impact on subsequent POM wastewater treatment systems.
[0005] Therefore, due to the increased amount of waste alkali and excessive salt content during the dioxane extraction process, the waste alkali, originally designed to neutralize wastewater, has become a burden on the polyoxymethylene wastewater treatment system. This has led to reduced sludge activity and poor treatment effect in the polyoxymethylene wastewater treatment system, which in turn affects the overall operation of the polyoxymethylene unit. Summary of the Invention
[0006] This invention provides a device for recovering alkaline solution from polyoxymethylene dioxane extraction, which overcomes the shortcomings of the prior art. It can effectively solve the problems of increased waste alkaline solution volume and excessive salt content in the existing dioxane extraction process, which leads to reduced sludge activity and poor treatment effect in the polyoxymethylene wastewater treatment system.
[0007] The technical solution of this utility model is achieved through the following measures: a polyoxymethylene dioxinex extraction alkali recovery device, comprising a waste alkali storage tank, a discharge pump, an alkali regeneration evaporator, an alkali regeneration condenser, a regenerated alkali storage tank, an organic waste liquid storage tank, and a dioxinex extract storage tank. A waste alkali inlet pipeline is fixedly connected to the lower inlet of the waste alkali storage tank. A first processing pipeline is fixedly connected between the lower outlet of the waste alkali storage tank and the inlet of the discharge pump. A second processing pipeline connects the outlet of the discharge pump to the upper inlet of the alkali regeneration evaporator. The top of the alkali regeneration evaporator... A third treatment pipeline is fixedly connected between the outlet of the alkaline regeneration condenser and the inlet of the alkaline regeneration condenser; a fourth treatment pipeline is fixedly connected between the outlet of the alkaline regeneration condenser and the inlet of the organic waste liquid storage tank; a waste liquid outlet pipeline is fixedly connected to the bottom outlet of the organic waste liquid storage tank; a fifth treatment pipeline is fixedly connected between the bottom outlet of the alkaline regeneration evaporator and the inlet of the regenerated alkaline storage tank; a sixth treatment pipeline is fixedly connected between the bottom outlet of the regenerated alkaline storage tank and the inlet of the dioxane extract storage tank; and a seventh treatment pipeline is fixedly connected between the sixth treatment pipeline and the waste alkaline inlet pipeline.
[0008] The following are further optimizations and / or improvements to the above-mentioned utility model technical solution: The above-mentioned alkaline regeneration evaporator is equipped with a wire mesh demister on the upper inner side and a heating coil on the lower inner side. The inlet of the heating coil is fixedly connected to a steam inlet pipeline, the outlet of the heating coil is fixedly connected to a steam outlet pipeline, the steam outlet pipeline is fixedly connected to a first cooling water inlet pipeline, the steam inlet pipeline is fixedly connected to a first cooling water outlet pipeline, and the steam outlet pipeline between the heating coil and the first cooling water inlet pipeline is fixedly connected to an vent pipeline.
[0009] The above-mentioned alkaline regeneration evaporator is equipped with a first liquid level detector on its side and a sodium hydroxide concentration detector at its bottom. A steam flow controller is fixedly installed on the steam inlet pipe on the left side of the first cooling water outlet pipe. A first temperature detector is installed at the bottom of the alkaline regeneration evaporator and a pressure detector is installed at the top of the alkaline regeneration evaporator. The steam flow controller is interlocked with the first temperature detector and the pressure detector respectively.
[0010] The lower inner side of the aforementioned waste alkali storage tank, organic waste liquid storage tank, and regenerated alkali storage tank is equipped with cooling coils. The inlets of the cooling coils of the waste alkali storage tank, organic waste liquid storage tank, and regenerated alkali storage tank are all fixedly connected to temperature-controlled medium inlet pipelines. The outlets of the cooling coils of the waste alkali storage tank, organic waste liquid storage tank, and regenerated alkali storage tank are all fixedly connected to temperature-controlled medium outlet pipelines. The cold source inlet of the alkali regeneration condenser is fixedly connected to a second cooling water inlet pipeline, and the cold source outlet of the alkali regeneration condenser is fixedly connected to a second cooling water outlet pipeline.
[0011] The above also includes a backup discharge pump, an eighth processing pipeline is fixedly connected between the first processing pipeline and the inlet of the backup discharge pump, and a ninth processing pipeline is fixedly connected between the outlet of the backup discharge pump and the second processing pipeline.
[0012] The above-mentioned waste alkali storage tank, organic waste liquid storage tank and regenerated alkali storage tank are all equipped with a second liquid level detector, the fourth treatment pipeline is equipped with a second temperature detector, and the regenerated alkali storage tank and the sixth treatment pipeline of the seventh treatment pipeline are equipped with a transfer pump and a peroxide content detector in sequence.
[0013] The aforementioned fifth treatment pipeline is fixedly connected to a demineralized water inlet pipeline, and the fifth treatment pipeline between the demineralized water inlet pipeline and the regenerated alkali storage tank is fixedly connected to the inlet of the organic waste liquid storage tank via a sewage outlet pipeline.
[0014] A fourth valve is provided on the first cooling water inlet pipeline, a third valve is provided on the first cooling water outlet pipeline, a first valve is provided on the steam inlet pipeline between the steam flow controller and the first cooling water outlet pipeline, and a second valve is provided on the steam outlet pipeline to the left of the first cooling water inlet pipeline.
[0015] This utility model has a reasonable and compact structure and is easy to use. By adding an alkali regeneration evaporator, an alkali regeneration condenser, a regenerated alkali storage tank, an organic waste liquid storage tank, and a dioxane extract storage tank and supporting pipelines after the waste alkali storage tank, it can efficiently realize the rational disposal and resource recovery of waste alkali, concentrate and remove impurities from the waste alkali for reuse, reduce the cost of preparing fresh alkali, reduce pollutant emissions, and reduce the burden on the polyoxymethylene wastewater treatment system. Attached Figure Description
[0016] Appendix Figure 1 This is a schematic diagram of the process flow of this utility model.
[0017] Appendix Figure 1The codes in the diagram are as follows: 1 for waste alkali storage tank, 2 for discharge pump, 3 for standby discharge pump, 4 for alkali regeneration evaporator, 5 for alkali regeneration condenser, 6 for regenerated alkali storage tank, 7 for organic waste liquid storage tank, 8 for dioxane extract storage tank, 9 for waste alkali inlet pipeline, 10 for first treatment pipeline, 11 for second treatment pipeline, 12 for third treatment pipeline, 13 for fourth treatment pipeline, 14 for waste liquid outlet pipeline, 15 for fifth treatment pipeline, 16 for sixth treatment pipeline, 17 for seventh treatment pipeline, 18 for heating coil, 19 for steam inlet pipeline, 20 for steam outlet pipeline, 21 for first cooling water inlet pipeline, 22 for first cooling water outlet pipeline, and 23 for first liquid level detector. 24 is a sodium hydroxide concentration detector; 25 is a steam flow controller; 26 is a cooling coil; 27 is a temperature-controlled medium inlet pipeline; 28 is a temperature-controlled medium outlet pipeline; 29 is a second cooling water inlet pipeline; 30 is a second cooling water outlet pipeline; 31 is an eighth treatment pipeline; 32 is a ninth treatment pipeline; 33 is a first temperature detector; 34 is a second liquid level detector; 35 is a second temperature detector; 36 is a pressure detector; 37 is a demineralized water inlet pipeline; 38 is a wastewater outlet pipeline; 39 is a wire mesh demister; 40 is a drain pipeline; 41 is a first valve; 42 is a second valve; 43 is a third valve; 44 is a fourth valve; 45 is a transfer pump; and 46 is a peroxide content detector. Detailed Implementation
[0018] This utility model is not limited to the following embodiments, and the specific implementation method can be determined according to the technical solution of this utility model and the actual situation.
[0019] Unless otherwise specified, all equipment and devices used in this invention are existing and commonly known in the art. For example, the first liquid level detector 23, the sodium hydroxide concentration detector 24, the second liquid level detector 34, the first temperature detector 33, the second temperature detector 35, the pressure detector 36, the wire mesh demister 39, and the peroxide content detector 46 are existing and commonly known equipment.
[0020] In this utility model, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.
[0021] The present invention will be further described below with reference to the embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1As shown, the polyoxymethylene dioxane extract alkali recovery device includes a waste alkali storage tank 1, a discharge pump 2, an alkali regeneration evaporator 4, an alkali regeneration condenser 5, a regenerated alkali storage tank 6, an organic waste liquid storage tank 7, and a dioxane extract storage tank 8. A waste alkali inlet pipeline 9 is fixedly connected to the lower inlet of the waste alkali storage tank 1. A first processing pipeline 10 is fixedly connected between the lower outlet of the waste alkali storage tank 1 and the inlet of the discharge pump 2. A second processing pipeline 11 connects the outlet of the discharge pump 2 to the upper inlet of the alkali regeneration evaporator 4. The top outlet of the alkali regeneration evaporator 4 is connected to the inlet of the alkali regeneration condenser 5. A third treatment pipeline 12 is fixedly connected between the outlets; a fourth treatment pipeline 13 is fixedly connected between the outlet of the alkali regeneration condenser 5 and the inlet of the organic waste liquid storage tank 7; a waste liquid outlet pipeline 14 is fixedly connected to the bottom outlet of the organic waste liquid storage tank 7; a fifth treatment pipeline 15 is fixedly connected between the bottom outlet of the alkali regeneration evaporator 4 and the inlet of the regenerated alkali storage tank 6; a sixth treatment pipeline 16 is fixedly connected between the bottom outlet of the regenerated alkali storage tank 6 and the inlet of the dioxane extract storage tank 8; and a seventh treatment pipeline 17 is fixedly connected between the sixth treatment pipeline 16 and the waste alkali inlet pipeline 9.
[0022] This invention involves sending the waste alkaline solution generated from the dioxapentane extraction process (containing 29% to 30% wt of sodium hydroxide, 1.70% wt of dioxapentane, 1.86% wt of HClO, 0.51% wt of MeOH, and 65.07% wt of H2O, etc.) to a waste alkaline solution storage tank 1, and then to an alkaline solution regeneration evaporator 4 for evaporation and concentration. The vapors generated in the alkaline solution regeneration evaporator 4 (such as organic compounds like dioxapentane, HClO, and MeOH) are evaporated. The solution is condensed in the alkali regeneration condenser 5, and the condensate is sent to the organic waste liquid storage tank 7 for further treatment or sent to the polyoxymethylene wastewater treatment system for treatment. The concentrate in the alkali regeneration evaporator 4 is cooled and sent to the regenerated alkali storage tank 6. The qualified concentrate (regenerated alkali with organic matter removed and sodium hydroxide concentration of about 45%) is sent to the dioxane extract storage tank 8 and can be used as the extract in the dioxane extraction process. The unqualified concentrate is returned to the waste alkali storage tank 1 for reprocessing.
[0023] This invention, by adding an alkali regeneration evaporator 4, an alkali regeneration condenser 5, a regenerated alkali storage tank 6, an organic waste liquid storage tank 7, and a dioxane extract storage tank 8, along with supporting pipelines, after the waste alkali storage tank 1, can efficiently achieve the rational disposal and resource recovery of waste alkali, concentrate and remove impurities from the waste alkali for reuse, reduce the cost of preparing fresh alkali, reduce pollutant emissions, and reduce the burden on the polyoxymethylene wastewater treatment system.
[0024] The above-mentioned polyoxymethylene dioxane extraction alkali solution recovery device can be further optimized and / or improved according to actual needs: Example 2: Its difference from Example 1 is as follows: (See attached) Figure 1As shown, the upper inner side of the alkaline regeneration evaporator 4 is provided with a wire mesh demister 39, and the lower inner side of the alkaline regeneration evaporator 4 is provided with a heating coil 18. The inlet of the heating coil 18 is fixedly connected to a steam inlet pipeline 19, and the outlet of the heating coil 18 is fixedly connected to a steam outlet pipeline 20. The steam outlet pipeline 20 is fixedly connected to a first cooling water inlet pipeline 21, and the steam inlet pipeline 19 is fixedly connected to a first cooling water outlet pipeline 22. The steam outlet pipeline 20 between the heating coil 18 and the first cooling water inlet pipeline 21 is fixedly connected to a venting pipeline 40.
[0025] During use, the wire mesh demister 39 efficiently separates liquid droplets from the gas, effectively reducing equipment corrosion. The heating coil 18 inside the alkali regeneration evaporator 4 ensures efficient evaporation. Steam is delivered to the heating coil 18 via the steam inlet pipeline 19, evaporating and concentrating the waste alkali solution inside the alkali regeneration evaporator 4, accelerating evaporation and improving evaporation efficiency. After concentration and evaporation, the concentrated liquid in the alkali regeneration evaporator 4 is cooled down to approximately 40°C via the added first cooling water inlet pipeline 21 and first cooling water outlet pipeline 22. When the cooling water in the heating coil 18 needs to be drained after cooling, the cooling water is discharged through the steam outlet pipeline 20 and the drain pipeline 40.
[0026] Example 3: Its difference from Example 2 is as follows: (See attached) Figure 1 As shown, the alkaline regeneration evaporator 4 is equipped with a first liquid level detector 23 on its side, and a sodium hydroxide concentration detector 24 is also provided at the bottom of the alkaline regeneration evaporator 4. A steam flow controller 25 is fixedly installed on the steam inlet pipe 19 on the left side of the first cooling water outlet pipe 22. A first temperature detector 33 is provided at the bottom of the alkaline regeneration evaporator 4, and a pressure detector 36 is provided at the top of the alkaline regeneration evaporator 4. The steam flow controller 25 is interlocked with the first temperature detector 33 and the pressure detector 36 respectively.
[0027] During operation, the liquid level in the alkali regeneration evaporator 4 is detected by the added first liquid level detector 23. When the liquid level of the waste alkali solution sent from the waste alkali solution storage tank 1 in the alkali regeneration evaporator 4 reaches 60%, the discharge pump 2 stops delivering the waste alkali solution. The sodium hydroxide concentration detector 24 detects the sodium hydroxide concentration of the concentrate in the alkali regeneration evaporator 4. When the sodium hydroxide concentration reaches about 45%wt, the evaporation and concentration can be stopped. The first temperature detector 33 and the pressure detector 36 can detect the internal temperature and pressure of the alkali regeneration evaporator 4, respectively. When the first temperature detector 33 detects that the internal temperature of the alkali regeneration evaporator 4 is higher than 130℃ or the pressure detector 36 detects that the internal pressure of the alkali regeneration evaporator 4 is higher than 25KPa, the steam flow controller 25 can be interlocked to stop the supply of steam, ensuring the safe operation of the alkali regeneration evaporator 4.
[0028] Example 4: It differs from Example 3 in that, as shown in the attached document... Figure 1 As shown, cooling coils 26 are provided on the lower inner side of the waste alkali storage tank 1, the organic waste liquid storage tank 7, and the regenerated alkali storage tank 6. The inlets of the cooling coils 26 of the waste alkali storage tank 1, the organic waste liquid storage tank 7, and the regenerated alkali storage tank 6 are all fixedly connected to temperature-controlled medium inlet water pipelines 27. The outlets of the cooling coils 26 of the waste alkali storage tank 1, the organic waste liquid storage tank 7, and the regenerated alkali storage tank 6 are all fixedly connected to temperature-controlled medium outlet water pipelines 28. The inlet of the cold source of the alkali regeneration condenser 5 is fixedly connected to a second cooling water inlet water pipeline 29, and the outlet of the cold source of the alkali regeneration condenser 5 is fixedly connected to a second cooling water outlet water pipeline 30.
[0029] During use, cooling coils 26 are installed on the inner side of the lower part of the waste alkali storage tank 1, the organic waste liquid storage tank 7, and the regenerated alkali storage tank 6. Each cooling coil 26 is equipped with a temperature-controlled medium inlet pipe 26 and a temperature-controlled medium outlet pipe 27. The temperature-controlled medium is water at a temperature of 50°C. The temperature of the waste alkali storage tank 1, the organic waste liquid storage tank 7, and the regenerated alkali storage tank 6 is controlled by the water at a temperature of 50°C. This effectively prevents the alkali in each storage tank from crystallizing at low temperatures, which can easily lead to pipe blockage and equipment damage.
[0030] Example 5: It differs from Examples 1 to 4 in that, as shown in the appendix... Figure 1 As shown, it also includes a backup discharge pump 3, an eighth processing pipeline 31 is fixedly connected between the first processing pipeline 10 and the inlet of the backup discharge pump 3, and a ninth processing pipeline 32 is fixedly connected between the outlet of the backup discharge pump 3 and the second processing pipeline 11.
[0031] During use, by adding a backup discharge pump 3, one is in operation and the other is on standby, to ensure the normal operation of the device.
[0032] Example 6: Its difference from Examples 1 to 5 is as follows: (See attached) Figure 1 As shown, a second liquid level detector 34 is installed on the waste alkali storage tank 1, the organic waste liquid storage tank 7 and the regenerated alkali storage tank 6, and a second temperature detector 35 is installed on the fourth treatment pipeline 13. A transfer pump 45 and a peroxide content detector 46 are installed sequentially on the sixth treatment pipeline 16 of the regenerated alkali storage tank 6 and the seventh treatment pipeline 17.
[0033] During use, by adding a second liquid level detector 34 to the waste alkali storage tank 1, the organic waste liquid storage tank 7, and the regenerated alkali storage tank 6, the liquid level in these tanks can be detected. A second temperature detector 35 is added to monitor the temperature of the condensate in the alkali regeneration condenser 5 in real time. A peroxide content detector 46 is added to ensure that when the peroxide content in the regenerated alkali in the regenerated alkali storage tank 6 is within acceptable limits, the qualified regenerated alkali is sent to the dioxane extract storage tank 8 for later use. When the peroxide content in the regenerated alkali is unacceptable, it is sent to the organic waste liquid storage tank 7 for further treatment via the sixth treatment pipeline 16, the seventh treatment pipeline 17, and the waste alkali inlet pipeline 9.
[0034] Example 7: Its difference from Examples 1 to 6 is as follows: (See attached) Figure 1 As shown, a demineralized water inlet pipeline 37 is fixedly connected to the fifth treatment pipeline 15, and a sewage outlet pipeline 38 is fixedly connected between the fifth treatment pipeline 15 and the inlet of the organic waste liquid storage tank 7 between the demineralized water inlet pipeline 37 and the regenerated alkali liquid storage tank 6.
[0035] During use, by adding a demineralized water inlet pipeline 37, the demineralized water is used to clean the alkaline regeneration evaporator 4. The wastewater after cleaning is sent to the organic waste liquid storage tank 7 through the fifth treatment pipeline 15. The temperature of the demineralized water is 90℃. Using 90℃ demineralized water for rinsing helps to improve the cleaning effect and reduce the cleaning time.
[0036] Example 8: It differs from Examples 2 to 9 in that: as shown in the appendix Figure 1 As shown, a fourth valve 44 is provided on the first cooling water inlet pipeline 21, a third valve 43 is provided on the first cooling water outlet pipeline 22, a first valve 41 is provided on the steam inlet pipeline 19 between the steam flow controller 25 and the first cooling water outlet pipeline 22, and a second valve 42 is provided on the steam outlet pipeline 20 on the left side of the first cooling water inlet pipeline 21.
[0037] During operation, by opening the first valve 41 and the second valve 42, steam is heated to the heating coil 18 via the steam inlet pipeline 19, and the heated steam is sent out via the steam outlet pipeline 20. By closing the first valve 41, the second valve 42 is closed after a 30-second delay, and then the third valve 43 is opened, followed by the fourth valve 44 after a 30-second delay, cooling water is sent to the heating coil 18 of the alkali regeneration evaporator 4 via the first cooling water inlet pipeline 21 and the steam outlet pipeline 20. The cooling water cools the concentrated liquid in the alkali regeneration evaporator 4 to about 40°C.
[0038] Depending on the needs, the pipelines and equipment of the polyoxymethylene dioxane extraction alkali recovery device may also be equipped with conventional valves, thermometers and pressure gauges known in the art, as required by production.
[0039] The above technical features constitute the embodiments of this utility model, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.
[0040] The process of using this utility model: First, the waste alkali solution generated by the dioxane extraction process is sent to the waste alkali solution storage tank 6 through the waste alkali solution inlet pipeline 9. The waste alkali solution in the waste alkali solution storage tank 6 is pumped to the alkali solution regeneration evaporator 4 by the discharge pump 2. When the first liquid level detector 23 detects that the liquid level in the alkali solution regeneration evaporator 4 has reached about 60%, the discharge pump 2 stops. Then, close the third valve 43 and the fourth valve 44, and open the first valve 41 and the second valve 42. 0.5 MPa steam is introduced into the heating coil 18 in the alkali regeneration evaporator 4 by the steam flow controller 25. The waste alkali in the alkali regeneration evaporator 4 is heated by the 0.5 MPa steam until it boils. The vapor (dioxanone, methanol and other organic matter) generated in the alkali regeneration evaporator 4 is separated by the wire mesh demister 39 and then sent to the alkali regeneration condenser 5 for condensation by the third treatment pipeline 12. When the first temperature detector 33 detects that the temperature in the alkali regeneration evaporator 4 reaches 115℃ to 118℃ and the first liquid level detector 23 detects that the liquid level in the alkali regeneration evaporator 4 has dropped, evaporation continues. When the sodium hydroxide concentration detector 24 detects that the sodium hydroxide concentration of the concentrate (i.e., the regenerated alkali) in the alkali regeneration evaporator 4 reaches about 45% wt, evaporation is completed and the steam supply is stopped. Next, close the first valve 41, and after a 30-second delay, close the second valve 42. Then, open the third valve 43, and after a 30-second delay, open the fourth valve 44. Start adding cooling water to the heating coil 18 of the alkali regeneration evaporator 4. Cool the regenerated alkali in the alkali regeneration evaporator 4 by cooling the alkali. When the first temperature detector 33 detects that the temperature of the concentrate is about 40°C, send the cooled regenerated alkali to the regenerated alkali storage tank 6 through the fifth processing pipeline 15. Finally, the regenerated alkali solution in the regenerated alkali solution storage tank 6 is tested by the peroxide content detector 46. When the peroxide content in the regenerated alkali solution is qualified, the qualified regenerated alkali solution is sent to the dioxane extract storage tank 8 for later use. When the peroxide content in the regenerated alkali solution is unqualified, it is sent to the waste alkali solution storage tank 1 for further treatment via the sixth treatment pipeline 16, the seventh treatment pipeline 17, and the waste alkali solution inlet pipeline 9. After draining the regenerated alkali solution from the alkali solution regeneration evaporator 4, the alkali solution regeneration evaporator 4 is cleaned with demineralized water at a temperature of 90°C. The demineralized water at approximately 90°C is sent to the alkali solution regeneration evaporator 4 via the demineralized water inlet pipeline 37. The wastewater after cleaning is sent to the organic waste liquid storage tank 7 via the fifth treatment pipeline 15 and the sewage outlet pipeline 38. The wastewater in the organic waste liquid storage tank 7 is sent to the post-treatment or polyoxymethylene wastewater treatment system for treatment via the waste liquid outlet pipeline 14.
Claims
1. A device for recovering alkaline solution extracted from polyoxymethylene dioxane, characterized in that... The system includes a waste alkali storage tank, a discharge pump, an alkali regeneration evaporator, an alkali regeneration condenser, a regenerated alkali storage tank, an organic waste liquid storage tank, and a dioxane extract storage tank. A waste alkali inlet pipeline is fixedly connected to the lower inlet of the waste alkali storage tank. A first treatment pipeline is fixedly connected between the lower outlet of the waste alkali storage tank and the inlet of the discharge pump. A second treatment pipeline connects the outlet of the discharge pump to the upper inlet of the alkali regeneration evaporator. A third treatment pipeline is fixedly connected between the top outlet of the alkali regeneration evaporator and the inlet of the alkali regeneration condenser. A fourth treatment pipeline is fixedly connected between the outlet of the alkali regeneration condenser and the inlet of the organic waste liquid storage tank. A waste liquid discharge pipeline is fixedly connected to the bottom outlet of the organic waste liquid storage tank. A fifth treatment pipeline is fixedly connected between the bottom outlet of the alkali regeneration evaporator and the inlet of the regenerated alkali storage tank. A sixth treatment pipeline is fixedly connected between the bottom outlet of the regenerated alkali storage tank and the inlet of the dioxane extract storage tank. A seventh treatment pipeline is fixedly connected between the sixth treatment pipeline and the waste alkali inlet pipeline.
2. The polyoxymethylene dioxane extraction alkali solution recovery device according to claim 1, characterized in that... The upper inner side of the alkaline regeneration evaporator is equipped with a wire mesh demister, and the lower inner side of the alkaline regeneration evaporator is equipped with a heating coil. The inlet of the heating coil is fixedly connected to a steam inlet pipeline, the outlet of the heating coil is fixedly connected to a steam outlet pipeline, the steam outlet pipeline is fixedly connected to a first cooling water inlet pipeline, the steam inlet pipeline is fixedly connected to a first cooling water outlet pipeline, and the steam outlet pipeline between the heating coil and the first cooling water inlet pipeline is fixedly connected to an vent pipeline.
3. The polyoxymethylene dioxane extraction alkali solution recovery device according to claim 2, characterized in that... The alkaline regeneration evaporator is equipped with a first liquid level detector on its side and a sodium hydroxide concentration detector at its bottom. A steam flow controller is fixedly installed on the steam inlet pipe to the left of the first cooling water outlet pipe. A first temperature detector is installed at the bottom of the alkaline regeneration evaporator and a pressure detector is installed at the top of the alkaline regeneration evaporator. The steam flow controller is interlocked with the first temperature detector and the pressure detector respectively.
4. The polyoxymethylene dioxane extraction alkali solution recovery device according to claim 1, 2, or 3, characterized in that... Cooling coils are installed on the inner side of the lower part of the waste alkali storage tank, organic waste liquid storage tank, and regenerated alkali storage tank. The inlets of the cooling coils of the waste alkali storage tank, organic waste liquid storage tank, and regenerated alkali storage tank are all fixedly connected to temperature-controlled medium inlet pipelines. The outlets of the cooling coils of the waste alkali storage tank, organic waste liquid storage tank, and regenerated alkali storage tank are all fixedly connected to temperature-controlled medium outlet pipelines. The cold source inlet of the alkali regeneration condenser is fixedly connected to a second cooling water inlet pipeline, and the cold source outlet of the alkali regeneration condenser is fixedly connected to a second cooling water outlet pipeline.
5. The polyoxymethylene dioxane extraction alkali solution recovery device according to claim 1, 2, or 3, characterized in that... It also includes a backup discharge pump, an eighth processing pipeline is fixedly connected between the first processing pipeline and the inlet of the backup discharge pump, and a ninth processing pipeline is fixedly connected between the outlet of the backup discharge pump and the second processing pipeline.
6. The polyoxymethylene dioxane extraction alkali solution recovery device according to claim 4, characterized in that... It also includes a backup discharge pump, an eighth processing pipeline is fixedly connected between the first processing pipeline and the inlet of the backup discharge pump, and a ninth processing pipeline is fixedly connected between the outlet of the backup discharge pump and the second processing pipeline.
7. The polyoxymethylene dioxane extraction alkali solution recovery device according to claim 1, 2, 3, or 6, characterized in that... A second liquid level detector is installed on the waste alkali storage tank, the organic waste liquid storage tank, and the regenerated alkali storage tank. A second temperature detector is installed on the fourth treatment pipeline. A transfer pump and a peroxide content detector are installed sequentially on the sixth treatment pipeline of the regenerated alkali storage tank and the seventh treatment pipeline. Or / and, a demineralized water inlet pipeline is fixedly connected to the fifth treatment pipeline. A sewage outlet pipeline is fixedly connected between the fifth treatment pipeline between the demineralized water inlet pipeline and the regenerated alkali storage tank and the inlet of the organic waste liquid storage tank.
8. The polyoxymethylene dioxane extraction alkali solution recovery device according to claim 4, characterized in that... A second liquid level detector is installed on the waste alkali storage tank, the organic waste liquid storage tank, and the regenerated alkali storage tank. A second temperature detector is installed on the fourth treatment pipeline. A transfer pump and a peroxide content detector are installed sequentially on the sixth treatment pipeline of the regenerated alkali storage tank and the seventh treatment pipeline. Or / and, a demineralized water inlet pipeline is fixedly connected to the fifth treatment pipeline. A sewage outlet pipeline is fixedly connected between the fifth treatment pipeline between the demineralized water inlet pipeline and the regenerated alkali storage tank and the inlet of the organic waste liquid storage tank.
9. The polyoxymethylene dioxane extraction alkali solution recovery device according to claim 5, characterized in that... A second liquid level detector is installed on the waste alkali storage tank, the organic waste liquid storage tank, and the regenerated alkali storage tank. A second temperature detector is installed on the fourth treatment pipeline. A transfer pump and a peroxide content detector are installed sequentially on the sixth treatment pipeline of the regenerated alkali storage tank and the seventh treatment pipeline. Or / and, a demineralized water inlet pipeline is fixedly connected to the fifth treatment pipeline. A sewage outlet pipeline is fixedly connected between the fifth treatment pipeline between the demineralized water inlet pipeline and the regenerated alkali storage tank and the inlet of the organic waste liquid storage tank.
10. The polyoxymethylene dioxin extraction alkali solution recovery device according to claim 2, 3, 6, 8, or 9, characterized in that... A fourth valve is provided on the first cooling water inlet pipeline, a third valve is provided on the first cooling water outlet pipeline, a first valve is provided on the steam inlet pipeline between the steam flow controller and the first cooling water outlet pipeline, and a second valve is provided on the steam outlet pipeline to the left of the first cooling water inlet pipeline.