The hottest way to realize the new washing concept

2022-08-22
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Realize the new water washing concept

under the new water washing concept jointly developed by several companies, the highly concentrated wastewater fluid is generated in specific areas of the device, so that the pretreated wastewater can obtain economic and reasonable heat treatment, and the wastewater load can be reduced by 90% at most. The colored wastewater generated after the reactive dyes are washed out is recycled after purification by a multi-stage membrane device and applied to all textile finishing processes

the German textile finisher van clewe, the Swiss textile equipment manufacturer Benninger and the German process and waste technology expert MDS have carried out constructive and successful cooperation. By adopting the new washing concept jointly developed, the actual waste water consumption per kilogram of fabric in all textile finishing processes has been reduced to 2.5l~3.5l, only one seventh of the standard

high concentration liquid reactive dyes are deposited as residual liquid in the chassis of soaking mill or membrane device, and are completely decolorized by electrochemical reduction process. The decolorization rate is 70% - 90%, and the energy consumption is minimal. This process does not produce any chlorine or sludge, that is, no reprocessing is required

beninger and MDS have reached an agreement to cooperate in this future oriented textile environmental protection field. The comprehensive capabilities of the two companies can meet the needs of each customer and provide effective problem solutions

extracta efficient washing schematic diagram

overview

the increasing demand and the increasingly mandatory policy of restricting sewage urge textile finishers to implement environmental protection production in order to achieve sustainable development, that is, to meet current needs, but also not hinder future development. These reasons are enough to enable the industry to seek innovative ideas and solutions with economy and ecology

in the process of realizing the new washing concept, the most important goal is to reduce the wastewater load (COD) and reduce the washing water consumption and steam consumption, which involves the water consumption of the whole system, not just the washing machine. In addition to the latest washing technology and low water consumption, the effective water consumption can be further reduced through the use of wastewater recycling, which is derived from the wastewater recovery process

the further goal of this project is to concentrate the reused wastewater and separate the impurities from the water. It can be concentrated directly from the origin (washing machine) or indirectly in the membrane device. Heat treatment is only suitable for the treatment of wastewater with low concentration

equipment concept

the equipment adopts beninger high-efficiency washing machine and uses the countercurrent principle, that is, the running direction of fabric is opposite to that of washing water. The equipment concept includes the following standard modes: high humidity impregnation; The double function reacta roller steam engine is used, which is not only the washing isolation room for pre washing dyed fabrics, but also the steam engine for pre-treatment processing; Six vertical roller trough washing isolation rooms with extracta rollers; 2 HydroVac vacuum pumping stations

beninger extracta roller trough high-efficiency washing machine is particularly suitable for countercurrent cleaning. Each washing compartment has up to 7 additional washing rooms. The washing liquid flows meandering between compartments according to the countercurrent principle, that is, the liquid flow is directed to the fabric from the opposite direction. Other well-known washing systems, such as horizontal or inclined washing machines, are not suitable for this application, because each washing room has only 2 rooms at most, so the concentration change of washing water is quite small

the parameters of the washing machine can be measured arbitrarily and maintained with a modern control system to ensure a variety of flexibility in water, countercurrent and processing direction

sample preparation in extracta open width washing machine

process concept

process steps include: continuous desizing - consider the separation and utilization of high concentration fluids, such as slurry recovery; Continuous and/or semi continuous bleaching and scouring - premise 4.2.5 fracture mechanics CT (compact tension) specimen fixture and accessories: the following specimen test requirements shall be met: CT (compact tension) specimen size B (thickness) × W (width): 12.5 × 25mm is that part of the fluid is separated and effectively utilized, and the wastewater is recycled; Wash out the dye - separate the concentrate, and then introduce washing water into the circulating system, with ultra-low water consumption

pretreatment process

the last three water washing compartments in the pretreatment process can be operated in the traditional form. The washing water flow adopts the counter flow method, and the required fluid is obtained by overflow, which is fed into the water washing compartment in front of the device. This part of the fluid is supplied to the pre concentration, and the slurry concentration formed in the pretreatment is measured. The counter flow washing water flows through the front washing compartment again, and the other high concentration washing water is applied to the fabric at the equipment inlet, with a high liquid absorption rate (sizing rate)

the fabric then reaches the steam engine, and the sizing agent expands in the steam engine, and the viscosity becomes smaller; Once leaving the steam engine, the fabric immediately flows through the first suction grid, and the slurry concentrate is extracted, and then fed to the water sealed steam engine, during which the operation is carried out based on the overflow principle; There are many concentrates collected in the overflow process, which can be recycled. From the last three, although there is still a certain gap in the production technology and scope of domestic flame retardant PP compared with foreign countries, a washing compartment extracts part of the liquid for numerical measurement and control to ensure that the processing conditions and parameters remain unchanged

pretreatment or desizing can be completed by two different processes: cold storage bleaching with oxidative desizing; Desizing with water soluble sizing AIDS. Desizing occurs directly inside the washing machine. The processing advantage is that the fabric is dried after entering the equipment, and becomes wet after leaving the washing machine. The moisture is removed during processing, so the waste water deposition is reduced; In addition, the slurry is not modified or degraded, so it can be recycled

the concentrate deposited in the pretreatment is collected into a separate container and then fed to a specially developed evaporator. The concentrate is dehydrated and then discharged as residual solids

in principle, this is a two-step roller dryer. A small part of the hot roll is immersed in the liquid and coated with a layer of concentrate film; The second step is to increase the slurry concentration, remove the dried residual solids with a scraper, and then reheat

wash out reactive dyes

in the washing out process, all compartments and steam engines can be used as water washing compartments. The steam engine adopts cold water countercurrent operation, which can wash out most of the unfixed dyes and residual alkali metals on the fabric; The fabric is then sent to the first suction grille to extract moisture as much as possible, so that the liquid bath can be separated well; The second suction grille is located behind the first washing compartment to promote and enhance the effect; The washing compartment behind is operated with hot water

water consumption can be effectively reduced by using HydroVac, because high concentration hydrolysates have been extracted from the fiber center and then enter the pre rinsing process. The wastewater produced by the washing process is purified by the multi-stage membrane device so that it can be reused

the coloring wastewater is collected in a container and then pumped to the membrane unit. The concentration of impurities (dyes, salts, fiber appendages, etc.) increases in the multistage membrane device. Clean water is again introduced into production as process warm water, which can save time and energy. The liquid dye concentrate evaporates. When the friction coefficient reaches a fixed value of 1, the tension machine may stop working due to friction and become a solid shape, which will be recycled in thermal processing

another option is electrochemical processing, during which the dye concentrate is decolorized and then discharged to the public sewage system

application effect

beninger washing machine has excellent performance. The discharge per kilogram of textiles is only 0.5l~0.7l, and the maximum cod load is 90% after pretreatment

those with small evaporation can be directly treated in situ, which is very consistent with van clewe's ecological and economic point of view, and is cheaper than being discharged into urban sewage devices for treatment; Van CLE is mainly due to buffer failure. We ecologically increase the solvent concentration in the roll evaporator and recover the residual solid substances in the heat treatment

the treatment method of concentrate should be determined according to the overall environmental conditions, which can be in the form of liquid or solid. In the project approval stage, we should consider the overall environmental situation. Only by adopting special ideas and equipment can we achieve the expected success

beninger high-efficiency water washer extracta integrates HydroVac, and the washing is only 1,5l/kg (cold 0,5, hot 1,0). Now, 3,0 l/kg (1,0+2,0) is required for medium color deep fabrics, and 4,5 (1,5+3,0) l/kg is required for dark fabrics, instead of 8~10 l/kg. Very dark colors, such as black and dark blue, usually require 12 l/kg, but now only 6 l/kg

the washing water is fed to the multi-stage membrane device. Compared with the traditional washing system, only a small amount of water needs to be added to the small device, which can greatly reduce the investment; The electric energy consumption of the membrane device is also small, so the operation cost of the whole process system is low

the multi-stage membrane device is initially ultrafiltration, with guaranteed nano filtration and/or reverse osmosis. The membrane can filter out impurities and long-chain organic molecules from wastewater at a temperature of up to 95 ℃, while nano filtration and/or reverse osmosis can remove almost all dissolved dyes and salts from water; The purified process water can be reintroduced into all textile finishing devices without negative impact on end products

the membrane device can operate continuously and without failure, and there is no need for labor expenditure in more than 5 years. Through the combined use of ultrafiltration and reverse osmosis, the wastewater recovery rate is more than 80%, and the recovered process water is decolorized after treatment in the membrane device. The COD value is 100~300mg/l, and the conductivity is close to 100 μ S/cm。

future prospects

during the pretreatment, the successful reduction of fluid volume and the characteristics of washing out dyes are impressive. The COD in the wastewater is reduced by 90%~95%. All washing out process water can be recycled, and the effective water consumption for treating 1kg fabric is reduced to one seventh of the traditional. The future economic and ecological advantages can also achieve the decolorization of recycled pulp and dye concentrate

the recovery of sizing AIDS is related to the production mode. Experience has proved that it is only suitable for chain processing enterprises (weaving and finishing by themselves) to recover sizing materials. Otherwise, in the separation operation, the finisher does not know the sizing formula of other weavers, so it cannot be recovered

however, van clewe provides sizing warp for weaving mills, so sizing aids can be recycled. The company is currently investigating environmental factors related to feasibility and cost. Preliminary tests show that wastewater-free processing can be basically achieved in this case

on the same fabric, the concentration of deposited size can be increased by adding 10% fresh size agent, and then directly introduced into its own sizing unit

today, decolorization of dye concentrates obtained from dye solutions and membrane devices by electrochemical reduction has become a more economically interesting process, with a cost of nearly 2.5 euros per cubic meter of concentrate

medium scale textile finishing companies need to be equipped with two CPB dye stations. The concentration deposited on the membrane device and the dip rolling chassis every day is 0.8 square meters ~1 cubic meter, and the decolorization cost is obviously negligible. The technology was jointly developed by Dornbirn Textile Research Institute in Austria, DyStar and beninger

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