RU2135662C1 - Fabric treating method and apparatus - Google Patents

Abstract

FIELD: textile industry. SUBSTANCE: method involves washing fabric smoothed with synthetic size; separating used washing water by means of membrane and returning clear water (permeate) and valuable components into process; conducting process at controlled water flow rate, with flow rate of solution under separation process flowing over membrane being 3-4 m/s. Prior to feeding to membrane filters, used washing water is subjected to flotation cleaning. Apparatus has washing baths, guiding rollers, squeezing shafts, pipeline system and circulation circuit, process vessel for flotation cleaning of used water. Vessel has inlet pocket, perforated horizontal plate positioned in lower part and froth remover positioned in upper part. EFFECT: wider operational capabilities in the usage of regenerate, increased efficiency in joint operation of fabric production and cleaning equipment. 3 cl, 1 dwg, 1 tbl

Description

 The invention relates to the decoration of textile materials, in particular, to the development of resource-saving technologies, providing for the protection of the environment from harmful industrial pollution.

 Finishing equipment of many foreign companies at the request of the customer can be mounted in parallel with water purification equipment. The degree of water purification is quite high, but its cost often exceeds the cost of finishing equipment, as well as the occupied area.

 With the development of membrane technology for water treatment, it became possible to create local treatment schemes for individual lines or baths with the return to the production cycle of purified water and valuable components, for example, dressing dye, etc.

 The problem of discharge of depleted, diluted impregnation baths is solved in the invention described in RF patent N 1795990 "Method for controlling the continuous processing of tissue, mainly wet squeezed" (Pudysheva TS, Khokhlov V.M. et al. D 06 B 23/18, BI 1993, N 6). The impregnating solution diluted by the wetted cloth is stabilized by concentration, directing it to the membrane separating elements to separate the excess solvent in the form of a permeate.

 In some cases, textile materials in the process of their manufacture and finish are subjected to impregnation with various technological solutions, which after certain treatments and to achieve the required quality indicators of the finished product must be completely removed from the fabric. These materials include dressing applied to the weaving warp during weaving. From 30 to 70% of wastewater pollution of finishing industries are pollution from tissue drying processes (G.V. Vasiliev, Yu.M. Laslov and others. Wastewater treatment of textile enterprises. - Moscow: Stroyizdat, 1981).

 Recently, the use of synthetic dressing materials has increased, due to many reasons, including the requirement to reduce wastewater pollution and the need to facilitate desizing when finishing using modern high-performance methods. Synthetic adhesive materials (PVA, CMC, etc.) can be separated from the used wash water unchanged and reused. Effective regeneration is prevented by strong dilution of the wash water, damage to the dressing during desizing, and contamination of the sizing material. The efforts of researchers have been directed toward solving these problems.

 In the invention according to the patent of the Russian Federation N 1444424 "Method for desizing the fabric and device for its implementation" (Kozlov V.V., Pudysheva T.S. et al., MKI D 06 B 23/20, Publ. BI 1988 N 46 (prototype) instead of introducing wetting agents and other chemical materials, it was proposed to steam for 3 to 4 with the fabric coming up for desizing, washing and membrane separation of the used washing water with the return of purified water and valuable components.This made it possible to obtain a cleaner regenerate with undamaged dressing, improve adhesive and cohesive properties of the dressing, which worse during accumulation of wetting agents; this also made it possible to obtain more concentrated waste water containing valuable components.

The invention in a fairly simple and economical way allows you to return to the production cycle of sizing up to 25 kg of PVA per hour for a dry product and purified water with a temperature of 65 - 75 ^o C.

However, during desizing of harsh cotton fabrics, nitrogen-containing, waxy, dyeing substances (morin, gossipetin, etc.), that is, naturally-occurring compounds associated with cellulose fibers, get into the spent washing water even at a temperature of 60 - 62 ^o C and above. Along with the plasticizers, oils, wetting agents, antifoaming agents introduced into the dressing composition, these substances are related to harsh cellulose fiber and do not adversely affect glue and other properties of the dressing, especially since after dressing the dressing must be removed from the fabric. The amount of impurities does not exceed 5 - 7% of the total amount of the regenerated synthetic polymer, but even this amount is enough to give an unpleasant odor to the regenerator during long-term storage or transportation, as a result of oxidation of impurities, which are biodegradable products, unlike synthetic polymer (PVA), not biodegradable. By specially conducted tests it was established that for this reason 20 to 38 kg of PVA per hour is lost, which could be used repeatedly if a cleaner product is obtained during its regeneration. In addition, the polymer purified from impurities can find wide application directly in the finishing industry for finishing and printing a wide range of fabrics.

 In addition to the aforementioned, there are difficulties in achieving the optimal conjugation between the amount of waste wash water discharged to the membrane separation and the performance of ultrafiltration plants: to avoid them, they go for the placement of spare storage tanks, although this is not always justified and necessary.

 The problem solved by the invention is to expand the technological capabilities in the use of the regenerate, to achieve the greatest efficiency and conjugation in the work of finishing and treatment equipment.

 To solve this problem, in the proposed method, the water consumption for processing the tissue and the surface of the membrane separation (number of membranes) is determined based on the quality parameters of the tissue (surface density, width, size of adhesive dressing), its processing speed, as well as the specific permeability of the membranes and the rate of flow of the solution above the membrane.

где P - расход воды в обработке ткани без учета на унос тканью при установившемся режиме, забираемый на ультрафильтрацию в мембранной установке, м³/ч;
V - скорость обработки ткани, м/ч;
G - поверхностная плотность ткани, г/см²;
h - ширина ткани, см;
r - коэффициент приклея шлихты, %;
k - коэффициент удаления шлихты с ткани, %;
C_к - концентрация синтетического полимера в концентрате, которую планируют получить, г/л;
φ • Z - производительность мембранной установки по пермеату, м³/ч;
φ - удельная производительность (проницаемость 1 мембраны), л/м² ч;
Z - количество мембран, шт;

- производительность мембранной установки по концентрату, м³/ч,
при скорости протекания разделяемого раствора над мембраной W = 3-4 м/с, при этом отработанную промывную воду перед подачей на мембранные фильтры подвергают дополнительной очистке флотацией.In the proposed method for treating fabric dressed with a synthetic dressing, including washing the fabric and membrane separation of the waste washing water with the return of purified water and valuable components to the production cycle, the water flow used when working the fabric directly to remove the dressing is set, controlled and selected for membrane separation in according to the dependency:

where P is the flow rate of water in the processing of tissue without taking into account the ablation by the fabric at steady state, taken for ultrafiltration in a membrane unit, m ³ / h;
V - tissue processing speed, m / h;
G is the surface density of the tissue, g / cm ² ;
h is the width of the fabric, cm;
r is the coefficient of adhesion of the dressing,%;
k is the coefficient of removal of dressing from the fabric,%;
C _to - the concentration of the synthetic polymer in the concentrate, which they plan to receive, g / l;
φ • Z - permeate membrane unit productivity, m ³ / h;
φ - specific productivity (permeability of 1 membrane), l / m ² h;
Z is the number of membranes, pcs;

- the performance of the membrane installation in concentrate, m ³ / h,
at a flow rate of the solution to be separated above the membrane, W = 3-4 m / s, while the spent wash water before being fed to the membrane filters is subjected to additional purification by flotation.

 The device for implementing the method comprises washing baths, guide rollers, squeezing shafts, a piping system and a pump and membrane filters included in the circulation circuit for the discharge of waste washing water. The device is additionally equipped with air suction nozzles installed in the concentrate pipelines, as well as a working tank with an inlet pocket formed by the wall of the tank and a continuous vertical plate turning into a perforated horizontal plate located in the lower part of the tank. The concentrate supply pipe is located above the inlet pocket. In the upper part of the tank there is a foam removal unit.

 The problem is solved, in particular, by the fact that the process of membrane separation of spent wash water containing synthetic polymer dressing, for example, PVA, is carried out at a solution flow rate above the membrane of 3-4 m / s, instead of 2.0 - 2.5 m / s at the same, generally accepted pressure in the system, equal to 0.1 - 0.5 MPa.

It has been established that conducting the ultrafiltration process at a solution speed above the membrane of 3-4 m / s has the following advantages:
1. Eliminates the influence of the concentration polarization process, which takes place especially for adhesive, viscous solutions, such as polymer dressing.

 2. Increases the performance of membrane ultrafilters, the number of which on this basis can be reduced.

 3. The movement of the working solution at a speed of 3-4 m / s provides a more complete suction of air into the solution through the corresponding nozzles and more active ejection of air into the working solution contained in the tank, which generally provides for the supersaturation and partial dissolution of air in the solution. This ensures the subsequent flotation and removal of impurities from the polymer concentrate.

 The supersaturation of the treated wash solution with air and its partial dissolution in it ensures the formation of particle-bubble complexes and the removal of particles with the smallest sizes that practically all of the above impurities have in comparison with the size of the macromolecules of the synthetic polymer. Microbubbles released from such a solution take out especially fine particles of impurities on the surface of the solution in the form of foam, which is removed.

 The process of membrane separation at a flow rate of the solution above the membrane W = 3-4 m / s and the location of the jet of solution emerging at the indicated speed at a distance of 0.4 ± 0.2 m above the liquid level in the working tank provides ejection of air into the solution and the direction of the resulting mixtures for a horizontal perforated plate, which acts as a dispersive grating. As a result, unwanted impurities are removed by flotation. The device diagram is shown in FIG. 1.

 A device for implementing the method includes washing baths 1, squeezing shafts 2, guide rollers 3, intake pipe 4, including a metal mesh for retaining mechanical impurities, a discharge pipe for the waste spent solution 5, a supply pump 6; the circulation circuit contains a working tank 7, a circulation pump 8, a pipeline for supplying a washing solution 9 to membrane filters 10 equipped with pressure gauges 11 and shutoff valves 12, a permeate discharge pipe 13, a concentrate pipe 14 having an air suction port 15. A concentrate return pipe from a pipeline 14 located at a height of 0.4 ± 0.2 m above the inlet pocket 16, formed by the wall of the tank 7 and a vertical continuous plate 17 located parallel to the wall of the tank and turning into horizontal perforations this plate 18, located parallel to the bottom in the lower part of the tank 7. The foam removal unit includes a horizontal rotating bar 19, shifting the foam in the direction of the inner wall of the tray 20, through which the latter is removed into the sewer. The device is equipped with shut-off valves 21 and a lead pipe 22 of the ready-to-use concentrate to the place of its use.

 The device operates as follows.

 The resulting washing solution containing all the components included in the dressing formulation (cottonseed oil, surfactants, stearox, glycerin, PVA, etc.), as well as impurities containing compounds naturally occurring to cellulose fibers (morin, gossiletine), through a sampling unit 4, including a mesh to retain mechanical impurities through the pipeline 5, the pump 6 is fed into the working tank 7. The circulation pump 8 through the pipeline 9 delivers the solution to the membrane filters 10, equipped with pressure gauges 11 and shutoff valves 12.

 Parameters of ultrafiltration: the rate of flow of the solution above the membrane 4 m / s, pressure 0.28 MPa, brand F-1 membrane, specific permeability 200 l / h, the number of membranes - 6, the concentration of PVA in the regenerator 20 g / l.

 During membrane separation, two streams are formed, one of which, permeate (purified water), is discharged through line 13 for reuse as hot process water. Through the concentrate pipe 14 having an air suction pipe 15, the second stream — the concentrate solution — enters the inlet pocket 16 formed by a vertical continuous plate 17 located parallel to the wall of the tank 7, turning into a horizontal perforated plate 8 located parallel to the bottom of the tank 7. Due to differences of 0.4 ± 0.2 m in the levels of the solution located in the tank and the solution exiting the pipe branch pipe 14, air is ejected and the solution aerated, which, bypassing the inlet pocket 16, per second Even the speed of the outlet stream of the concentrated solution falls under the perforated plate 8, which acts as a dispersing grating. Here, the air is crushed into smaller bubbles, and the formation of particle-bubble complexes that float to the surface of the solution in the form of foam. The impurities mentioned above, as well as small fibers, are easily flotated, with the help of which the synthetic polymer material (PVA) is purified from impurities. The foam removal unit located in the upper part of the container includes a horizontal rotating bar 19 that moves the foam along the inner wall of the tray 20, along which the foam is discharged into the sewer.

 The solution is concentrated, passing the next cycle of membrane separation due to the removal of water in the form of permeate, and is also purified from impurities by removing the latter in the form of foam. Upon reaching a given concentration of the resulting regenerate (20 g / l PVA) by switching valves 21, the circulation pump 8 delivers the purified product to the place of its reuse through the pipe 22.

 The obtained PVA regenerate was used in the preparation of dressings for the treatment of bleached fabrics or printed with both white-earth and soil patterns; in the preparation of thickeners for printing inks, as well as in the sizing of weaving bases (during long-term storage or transportation of the latter (for more than 30 days) without any complications.

 In the conditions of ZiMa JSC (F. Zinoviev weaving and finishing factory), production tests were carried out to assess the possibility of using waste washing water containing polyvinyl alcohol (PVA) for the preparation of dressings.

Desizing was subjected to fabric art. 82068, the basics of which were sized with the composition, g / l:
PVA (brand BI-H) - 80
PVA (grade 6-1-H) - 100
cottonseed oil - 0.8
wetting agent - 0.4
stearox-6 - 1.3
glycerin - 8.0
The fabric came at a speed of 60 m / min into the bath 1, passing along the guide rollers 3, washed with hot water (temperature 85-95 ^o C), squeezed to a residual moisture = 90% in spin 2.

Объем воды, подаваемый в ванну, с учетом на унос ее тканью составил:

По приводимому способу и устройству был получен концентрат, содержащий 20 г/л ПВС, и на его основе приготовлен аппрет следующего состава, г/л:
ПВС - 10
Хлористый аммоний - 3,0
Карбамол-2 - 40
Оптический отбеливатель - 1,5
Данным аппретом обработаны ткани арт. 50 и 548 по ходовому режиму на линии ЛАО.Water consumption was determined and maintained based on the above dependence. The amount of water used to wash the tissue and taken to the membrane separation was:

The volume of water supplied to the bath, taking into account the ablation of its fabric was:

According to the presented method and device, a concentrate containing 20 g / l PVA was obtained, and on its basis a sizing of the following composition was prepared, g / l:
PVA - 10
Ammonium Chloride - 3.0
Carbamol-2 - 40
Optical Brightener - 1.5
This size processed fabrics art. 50 and 548 on the running mode on the LAO line.

Processing mode: speed 70 m / min; spin 90 ± 5%; drying temperature 100-120 ^o C to a moisture content of 25-30% - on drums, then to conditioned humidity in the chain field of the line. The quality of the fabric corresponds to the existing GOST and TU, the test results are shown in the table.

Claims (3)

1. A method of treating fabric lined with synthetic dressing, including washing the fabric and membrane separation of the used wash water with the return to the production cycle of purified water and valuable components, characterized in that the fabric treatment process is carried out at a controlled flow rate, determined in accordance with the relationship:

where P is the flow rate of water, m ³ / h taken to the membrane separation;
G is the surface density of the tissue, g / cm ² ;
h is the width of the fabric, cm;
V - tissue processing speed, m / h;
r is the coefficient of adhesion of the dressing,%;
K is the removal coefficient of the dressing in the volume (m ³ / h),%;
C _to - the concentration of the polymer dressing in the concentrate, which must be obtained, g / l;
φ is the specific productivity (permeability of the membranes), l / m ² h;
Z is the separation surface, m ² or the number of membranes at a flow rate of the solution to be separated above the membrane;
W = 3 - 4 m / s, while the spent wash water before being fed to the membrane filters is subjected to additional flotation treatment.  2. A device for treating fabric lined with synthetic dressing, containing washing baths, guide rollers, squeezing shafts, a piping system and a pump and membrane filters included in the circulating circuit for discharging waste washing water, characterized in that it is additionally equipped with a working tank with an inlet pocket, formed by the wall of the tank and a continuous vertical plate passing into a perforated horizontal plate located in the lower part of the tank, while the main concentrate pipeline Shchen suction nozzles and air inlet is positioned above the working container pocket.  3. The device according to claim 2, characterized in that it is equipped with a foam removal unit located in the upper part of the working tank.

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