System suitable for recycling dye in decolorized waste liquid

Abstract

The utility model discloses a system suitable for recycling dye in decolorized waste liquid, which relates to the technical field of textile dye stripping and recycling and comprises a reactor, a dehydration helix a, a dilution helix, a dehydration helix b, a self-cleaning filter a, a dye separation device a, a self-cleaning filter b and a dye separation device b, the dehydration helix a, the dilution helix, the dehydration helix b, the self-cleaning filter a and the dye separation device a are sequentially arranged on the rear side of the reactor station; the self-cleaning filter b and the dye separation device b are sequentially arranged on the rear side of the station of the dehydration screw b; the dye separation device a is connected to a decoloring solution blending tank; the dye separation device b is connected to the dilution screw and is connected to the decolorizing solution preparation tank for supplementing water; and the desorption liquid conveying pipelines of the dye separation device a and the dye separation device b are connected to a purification and concentration station. According to the dye stripping device, dye can be thoroughly stripped in the process of recovering the dye of old textiles, and the efficient recovery of the dye is realized.

Description

Technical Field

[0001] This utility model relates to the field of textile dye stripping and recycling technology, and in particular to a dye recycling and reuse system applicable to decolorization waste liquid. Background Technology

[0002] With the increasing scarcity of textile raw material resources, the high-value recycling of cotton-containing waste textiles has become an inevitable trend for the green development of the fiber industry. Preparing dissolving pulp is one of the effective ways to achieve high-value recycling of cotton-containing waste textiles. However, in the production process of preparing dissolving pulp from waste textiles, the wastewater generated from stripping dyes from the textiles causes resource waste and serious environmental pollution, failing to meet the requirements of modern industry for environmental protection and resource reuse.

[0003] Chinese patent document CN116057114A discloses a method for depolymerizing waste polymer materials and a system for using it. This utility model can separate dyes from fabrics and includes a system utilizing this separation method. However, when recycling dyes from fabrics, a decolorizing agent is usually used to decolorize the fabric, which has been pulverized into a paste, and then the dyes contained in the decolorizing solution are separated and recovered.

[0004] Therefore, there is a need to design a recycling system for efficiently stripping and recovering dyes from waste textiles. This system aims to solve the problems of waste dye resources and potential environmental pollution caused by waste textiles. It utilizes a decolorizing solution to strip dyes from textiles and recover the dyes in the decolorizing solution with high purity, so that the recovered dyes can be reused in the textile or other related industries. Utility Model Content

[0005] To address the shortcomings of the existing technology, this utility model provides a dye recovery and reuse system suitable for decolorization wastewater in the field of textile dye stripping and recycling.

[0006] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: a dye recovery and reuse system suitable for decolorization waste liquid, including a reactor, a dehydration spiral a, a dilution spiral, a dehydration spiral b, a self-cleaning filter a, a dye separation device a, a self-cleaning filter b, and a dye separation device b; the dehydration spiral a, the dilution spiral, and the dehydration spiral are sequentially arranged behind the reactor station through a slurry conveying pipe I; the self-cleaning filter a and the dye separation device a are sequentially arranged behind the reactor station through a decolorization liquid conveying pipe I; the decolorization liquid outlet end of the dehydration spiral a and the decolorization liquid outlet end of the dye separation device a are connected by a decolorization liquid conveying pipe. Channel II is connected to the reactor; the self-cleaning filter b and the dye separation device b are sequentially arranged behind the dewatering spiral b station via washing water conveying pipe I; the decolorizing liquid outlet of the dye separation device a is connected to the decolorizing liquid mixing tank via a decolorizing liquid conveying pipe; the washing water outlet of the dye separation device b is connected to the dilution spiral via washing water conveying pipe II, and is also connected to the decolorizing liquid mixing tank to replenish the water required for mixing the decolorizing liquid; a slurry conveying pipe II connects the self-cleaning filter a and the dewatering spiral a; the deionized liquid conveying pipes of the decolorizing liquid outlet of the dye separation device a and the washing water outlet of the dye separation device b are connected to the purification and concentration station.

[0007] Furthermore, the decolorizing liquid preparation tank is located on the decolorizing liquid conveying pipeline II between the dye separation device a and the reactor, and the decolorizing liquid preparation tank is provided with an injection port for injecting the decolorizing agent.

[0008] Furthermore, the decolorizing liquid preparation tank is connected to a steam pipeline, the steam pipeline is equipped with a steam regulating valve, and the decolorizing liquid preparation tank is equipped with a thermometer, the steam regulating valve and the thermometer being interlocked.

[0009] Furthermore, the decolorizing liquid conveying pipeline II is equipped with a decolorizing pump at the outlet end of the decolorizing liquid mixing tank, and a flow meter and a decolorizing liquid regulating valve are installed at the inlet end near the reactor. When the reactor is fed with slurry, the decolorizing liquid regulating valve is interlocked with the decolorizing pump frequency converter, the flow meter and the feed mixing screw frequency converter.

[0010] Furthermore, the slurry conveying pipe I is located at the bottom outlet end of the reactor and branches off to the decolorizing liquid conveying pipe III. The outlet end of the decolorizing liquid conveying pipe III is connected to the decolorizing liquid conveying pipe II located between the reactor and the decolorizing liquid mixing tank. The outlet end of the decolorizing liquid output pipe III is equipped with a decolorizing liquid regulating valve II and a flow meter II. During decolorization in the reactor, the decolorizing pump frequency converter is interlocked with the decolorizing liquid regulating valve II and the flow meter II.

[0011] Furthermore, a washing water tank is provided on the washing water delivery pipe I between the dehydration spiral b and the self-cleaning filter b.

[0012] Furthermore, a washing water pump is installed on the washing water delivery pipeline I between the washing water tank and the self-cleaning filter b, and a washing water regulating valve and a flow meter are installed on the washing water delivery pipeline II between the dye separation device b and the dilution spiral. The dilution spiral is interlocked with the washing water pump frequency converter, the flow meter and the washing water regulating valve.

[0013] Furthermore, the dewatering spiral b and the self-cleaning filter b are connected to the pulping station via the slurry conveying pipe III.

[0014] Furthermore, there are two dye separation devices a arranged in parallel, and dye separation devices a and b are resin columns or nanofiltration membranes.

[0015] In summary, this utility model has the following beneficial effects:

[0016] (1) A certain amount of blended fiber is fed into the reactor, and the decolorizing liquid is pumped in from the bottom of the reactor and drawn out from the top; it enters the self-cleaning filter and removes suspended solids, grease and other impurities in the decolorizing liquid by filtration; then it is introduced into the dye separation device, and after the dye is separated, a certain amount of decolorizing agent is added and it enters the reactor again to form a cycle; this system is suitable for the recycling and reuse of dye in decolorizing waste liquid, and can effectively solve the problem of resource waste and environmental pollution caused by dye wastewater in the process of preparing dissolving pulp from waste textiles.

[0017] (2) The entire system includes multiple components such as a reactor, dewatering spiral, dilution spiral, self-cleaning filter, and dye separation device. These components are connected in an orderly manner through a rationally designed slurry conveying pipeline, decolorizing liquor conveying pipeline, and washing water conveying pipeline to form a complete and efficient dye recycling process. This integrated system design ensures the continuity and efficiency of dye stripping and recycling from waste textiles.

[0018] (3) The dye recovery and reuse system in the decolorization waste liquid is equipped with a decolorization liquid preparation tank and a washing water tank. The decolorizing agent can be injected as needed, and water is injected through the dilution screw and then through the washing water tank. The interlocking control mechanism can accurately adjust the flow rate and delivery status of the decolorization liquid, as well as the supply and flow rate of the washing water, thereby improving the quality of dye recovery. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the dye recovery system.

[0020] The reference numerals in the attached figures are explained as follows:

[0021] 1. Reactor; 2. Dewatering screw a; 3. Dilution screw; 4. Dewatering screw b; 5. Self-cleaning filter a; 6. Dye separation device a; 7. Self-cleaning filter b; 8. Dye separation device b; 9. Decolorizing liquor mixing tank; 901. Steam pipe; 902. Steam regulating valve; 903. Thermometer; 10. Washing water tank; 11. Pulping station; 12. Purification and concentration station; 13. Pulp conveying pipe I; 14. Decolorizing liquor conveying pipe I; 15. Decolorizing liquor conveying pipe... Pipeline II; 151, Decolorizing Pump; 152, Flow Meter I; 153, Decolorizing Liquid Regulating Valve I; 16, Washing Water Pipeline I; 161, Washing Water Pump; 17, Washing Water Pipeline II; 171, Washing Water Regulating Valve; 172, Flow Meter III; 18, Slurry Pipeline II; 19, Desorption Liquid Pipeline; 20, Decolorizing Liquid Pipeline III; 201, Decolorizing Liquid Regulating Valve II; 202, Flow Meter II; 203, Slurry Pipeline III. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the embodiments.

[0023] Example 1:

[0024] like Figure 1 As shown, a dye recovery and reuse system suitable for decolorizing wastewater includes a reactor 1, a dehydration spiral a2, a dilution spiral 3, a dehydration spiral b4, a self-cleaning filter a5, a dye separation device a6, a self-cleaning filter b7, and a dye separation device b8. The dehydration spiral a2, dilution spiral 3, and dehydration spiral are sequentially arranged behind the reactor 1 via a slurry conveying pipe I13. The self-cleaning filter a5 and dye separation device a6 are sequentially arranged behind the reactor 1 via a decolorizing liquid conveying pipe I14. The decolorizing liquid outlet of the dehydration spiral a2 and the decolorizing liquid outlet of the dye separation device a6 are connected to the reactor 1 via a decolorizing liquid conveying pipe II15. The self-cleaning filter b7 and the dye separation device b8 are sequentially arranged behind the dewatering spiral b4 station via a washing water conveying pipe I16; the decolorizing liquid outlet of the dye separation device a6 is connected to the decolorizing liquid mixing tank 9; the washing water outlet of the dye separation device b8 is connected to the dilution spiral 3 via a washing water conveying pipe II17, and is also connected to the decolorizing liquid mixing tank 9 to supplement the water required for mixing the decolorizing liquid; a slurry conveying pipe II18 connects the self-cleaning filter a5 and the dewatering spiral a2; the deionized liquid conveying pipe 19 of the decolorizing liquid outlet of the dye separation device a6 and the washing water outlet of the dye separation device b8 is connected to the purification and concentration station 12.

[0025] In reactor 1, a decolorizing agent is pumped in and reacts with textile fibers to form a slurry. After separation by dye separation devices a6 and b8, a concentrated dye solution and a dilute separation solution are formed. The concentrated dye solution is purified and concentrated to obtain the dye. The slurry output from the self-cleaning filter b7 and the dehydration screw b4 can be collected separately.

[0026] The decolorizing solution for separating dyes circulates in the system, continuously peeling the dyes off the fibers. The dyes are then separated from the fiber phase. The separated concentrated dye solution is treated to obtain a purified and concentrated dye product, while the separated dilute solution containing the decolorizing solution is recycled. In this way, the dye content in the decolorizing solution is always kept at a low point, which is equivalent to continuously using fresh decolorizing solution to peel off the dyes, avoiding the dyes from re-dyeing the fibers. This ensures thorough dye removal and effectively guarantees the dye removal effect on the fibers.

[0027] Example 2:

[0028] Based on the dye recovery and reuse system for decolorization wastewater described in Example 1, such as Figure 1 As shown, the decolorizing liquid preparation tank 9 is located on the decolorizing liquid conveying pipeline II15 between the dye separation device a6 and the reactor 1, and the decolorizing liquid preparation tank 9 is provided with an injection port for injecting decolorizing agent.

[0029] The decolorizing liquid preparation tank 9 is connected to a steam pipe 901. A steam regulating valve 902 is provided on the steam pipe 901. A thermometer 903 is provided inside the decolorizing liquid preparation tank 9. The steam regulating valve 902 and the thermometer 903 are interlocked.

[0030] The decolorizing liquid conveying pipeline II15 is equipped with a decolorizing pump 151 at the outlet end of the decolorizing liquid mixing tank 9, and a flow meter 152 and a decolorizing liquid regulating valve 153 are installed near the inlet end of the reactor 1. When the reactor 1 is fed with slurry, the decolorizing liquid regulating valve 153 is interlocked with the frequency converter of the decolorizing pump 151, the flow meter 152 and the frequency converter of the feed mixing screw.

[0031] The slurry conveying pipe I13 is located at the bottom outlet end of reactor 1, and branches into the decolorizing liquid conveying pipe III20. The outlet end of the decolorizing liquid conveying pipe III20 is connected to the decolorizing liquid conveying pipe II15 located between reactor 1 and decolorizing liquid mixing tank 9. The outlet end of the decolorizing liquid output pipe III is equipped with a decolorizing liquid regulating valve II201 and a flow meter II202. When decolorizing in reactor 1, the frequency converter of decolorizing pump 151 is interlocked with the decolorizing liquid regulating valve II201 and the flow meter II202.

[0032] A washing water tank 10 is installed on the washing water delivery pipe I16 between the dehydration spiral b4 and the self-cleaning filter b7. A washing water pump 161 is installed on the washing water delivery pipe I16 between the washing water tank 10 and the self-cleaning filter b7. A washing water regulating valve 171 and a flow meter 172 are installed on the washing water delivery pipe II17 between the dye separation device b8 and the dilution spiral 3. The dilution spiral 3 is interlocked with the frequency converter of the washing water pump 161, the flow meter 172, and the washing water regulating valve 171.

[0033] The dewatering spiral b4 and the self-cleaning filter b7 are connected to the pulping station 11 via the slurry conveying pipe III203.

[0034] In this embodiment, reactor 1 is at least one reactor 1. The feeding mixing screw of reactor 1 fully mixes the dry-crushed fiber with the decolorizing liquid. The alkali in the decolorizing liquid wets the fiber, preventing the dry fiber from floating on the decolorizing liquid and failing to decolorize properly.

[0035] Dye extraction methods include:

[0036] 1. The dye that has been stripped off is adsorbed onto a resin. Once the resin is saturated, a desorbent is used to desorb the dye from the resin, resulting in a highly concentrated dye solution. This dye solution is then recycled and purified to obtain the dye and the desorbent, which can be reused. The decolorized solution from the resin-separated dye is recycled after replenishing the decolorizing agent.

[0037] 2. By replacing the resin column with a nanofiltration membrane, the dye solution from the reaction unit is passed through the nanofiltration membrane to obtain a high-concentration dye solution and a dye-free decolorizing solution. The dye-free decolorizing solution is recycled after replenishing the decolorizing agent, while the high-concentration dye solution is recovered and purified to obtain the dye.

[0038] A fixed amount of blended fiber is fed into reactor 1 and thoroughly mixed with the decolorizing liquid to impregnate the fiber. After the fiber is fed in, the decolorizing liquid is pumped in from the bottom of the reactor and led out through a multi-hole top. It then enters a self-cleaning filter to remove suspended solids, grease and other impurities from the decolorizing liquid through filtration. Then, a dye separation device, such as a resin column or nanofiltration membrane, is introduced to separate the dye. After the dye is separated, a fixed amount of decolorizing agent is added and the liquid re-enters the reaction tower to form a cycle.

[0039] During fiber feeding, the feed mixing screw frequency converter is interlocked with the decolorizing liquor flow meter 152 and the decolorizing liquor regulating valve 153 to ensure a uniform slurry enters the reaction unit. During the decolorization reaction, i.e., dye stripping, an interlock is formed between the decolorizing liquor flow meter 202, the decolorizing pump 151, and the decolorizing liquor regulating valve 153. Depending on the raw material and the ease of dye stripping, an appropriate dye stripping speed, i.e., the decolorizing liquor inflow rate, is selected.

[0040] After dye separation unit A6 becomes saturated with adsorbed dye, the decolorizing solution is transferred to dye separation unit B8 for continued operation. An online colorimeter is connected to the resin column outlet to determine whether the resin is saturated. Dye separation unit A6 is then regenerated by introducing a desorbent. The dye on the adsorbent is desorbed through methods such as heating and adding chemical reagents. Simultaneously, the desorbed and enriched dye solution is purified and concentrated. Impurities and residues are removed through methods such as distillation and filtration to obtain a pure dye product.

[0041] If a nanofiltration membrane is used, the concentrated solution rich in dye is purified and concentrated, while the dilute solution is replenished with a certain amount of decolorizing agent and then re-enters the reaction tower, forming a cycle.

[0042] After decolorization is completed, production is switched from the completed reactor 1 to another reactor 1 for continuous production. The completed reactor 1 then begins to pump the decolorized slurry from the bottom into the next process. At this time, the frequency converter of the slurry pump is interlocked with the frequency converters of the dewatering screw a2, dilution screw 3 and dewatering screw b4 to ensure the matching of the production capacity of the whole process.

[0043] In the above embodiments, the decolorizing agent is thiourea dioxide, which begins to decompose in an alkaline aqueous solution at 55°C, producing urea and hyposulfuric acid. Hyposulfuric acid is then generated. , and thus generate and Urea continues to decompose at 80℃, forming CO2 and NH3, which can be utilized... The strong reducing properties of dyes; sodium dithionite, due to the intermediate valence state of sulfur in its components, is chemically unstable and exhibits strong reducing properties; surfactants—fatty alcohol polyoxyethylene ether (Pingpingjia) or sodium dodecylbenzene sulfonate—reduce the surface tension of liquids and increase their wettability. It also has certain emulsifying, dispersing, and stabilizing properties; chelating agents—sodium gluconate (chelates metal ions); dimethyl sulfoxide (DMSO) can be used as a destaining agent for synthetic fibers.

[0044] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A system for recovery and reuse of dyes from decolorized effluent, characterized in that, The device comprises a reactor (1), a dewatering screw a (2), a dilution screw (3), a dewatering screw b (4), a self-cleaning filter a (5), a dye separation device a (6), a self-cleaning filter b (7) and a dye separation device b (8); the dewatering screw a (2), the dilution screw (3) and the dewatering screw are sequentially arranged at the rear side of the reactor (1) through slurry conveying pipeline I (13); the self-cleaning filter a (5) and the dye separation device a (6) are sequentially arranged at the rear side of the reactor (1) through decolorizing liquid conveying pipeline I (14); the outlet end of the dewatering screw a (2) and the outlet end of the dye separation device a (6) are connected with the reactor (1) through decolorizing liquid conveying pipeline II (15); the self-cleaning filter b (7) and the dye separation device b (8) are sequentially arranged at the rear side of the dewatering screw b (4) through washing water conveying pipeline I (16); the outlet end of the dye separation device a (6) is connected to a decolorizing liquid adjusting tank (9); the outlet end of the dye separation device b (8) is connected to the dilution screw (3) through washing water conveying pipeline II (17) and is also connected to the decolorizing liquid adjusting tank (9) to supplement the water required for adjusting the decolorizing liquid; the slurry conveying pipeline II (18) is connected between the self-cleaning filter a (5) and the dewatering screw a (2); the resolving liquid conveying pipeline (19) connected to the outlet end of the dye separation device a (6) and the outlet end of the dye separation device b (8) is connected to a purification and concentration station (12).

2. The system as claimed in claim 1, wherein, The decolorizing liquid adjusting tank (9) is arranged on the decolorizing liquid conveying pipeline II (15) between the dye separation device a (6) and the reactor (1); the decolorizing liquid adjusting tank (9) is provided with an injection inlet for injecting a decolorizing agent.

3. The system as claimed in claim 2, wherein, The decolorizing liquid adjusting tank (9) is connected with a steam pipeline (901); the steam pipeline (901) is provided with a steam adjusting valve (902); the decolorizing liquid adjusting tank (9) is provided with a thermometer (903); the steam adjusting valve (902) and the thermometer (903) are interlocked.

4. The system as claimed in claim 3, wherein, The decolorizing pump (151) is arranged at the outlet end of the decolorizing liquid adjusting tank (9); the flowmeter one (152) and the decolorizing liquid adjusting valve one (153) are arranged near the inlet end of the reactor (1); when the slurry is fed into the reactor (1), the decolorizing liquid adjusting valve one (153) is interlocked with the decolorizing pump (151) frequency converter, the flowmeter one (152) and the feed mixing screw frequency converter.

5. The system as claimed in claim 4, wherein, The slurry conveying pipeline I (13) is arranged at the bottom outlet end of the reactor (1); the slurry conveying pipeline I (13) is branched into a decolorizing liquid conveying pipeline III (20); the outlet end of the decolorizing liquid conveying pipeline III (20) is connected to the decolorizing liquid conveying pipeline II (15) between the reactor (1) and the decolorizing liquid adjusting tank (9); the outlet end of the decolorizing liquid conveying pipeline III (20) is provided with the decolorizing liquid adjusting valve two (201) and the flowmeter two (202); when the reactor (1) is decolorized, the decolorizing pump (151) frequency converter is interlocked with the decolorizing liquid adjusting valve two (201) and the flowmeter two (202).

6. The system as claimed in claim 1, wherein, The washing water conveying pipeline I (16) between the dehydration screw b (4) and the self-cleaning filter b (7) is provided with a washing water tank (10).

7. The system as claimed in claim 6, wherein, The washing water conveying pipeline I (16) between the washing water tank (10) and the self-cleaning filter b (7) is provided with a washing water pump (161), the washing water conveying pipeline II (17) between the dye separation device b (8) and the dilution screw (3) is provided with a washing water regulating valve (171) and a flowmeter three (172), and the dilution screw (3) is interlocked with the washing water pump (161) frequency converter, the flowmeter three (172) and the washing water regulating valve (171).

8. The system for recovery and reuse of dyes from decolorized waste liquid according to any one of claims 1-7, characterized in that, The dehydration screw b (4) and the self-cleaning filter b (7) are connected to the pulping station (11) through the slurry conveying pipeline III (203).

9. The system as claimed in claim 8, wherein, The dye separation device a (6) is parallel to two, and the dye separation device a (6) and the dye separation device b (8) are resin columns or nanofiltration membranes.

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